Siffre's life in the cave was spartan at best. He lived in a tent that sat on a small wooden platform with a bed, a table, a chair, and a phone that he could use to call his research team above ground. His underground home was equipped with a single lightbulb, which provided a soft glow to the piles of frozen food and 800 gallons of water nearby. There were no clocks or calendars, no way for him to discover what time it was or whether it was day or night. And this was how he lived, alone, for six months.
Siffre's work, along with the experiments of a handful of other researchers, helped kickstart a scientific interest in sleep that has resulted in sleep performance centers at major universities like Harvard and the University of Pennsylvania. Given that we spend almost 1/3 of our lives sleeping, it's hard to believe the topic has only gained a large scientific following in recent years.
In this article, I'll share the science of sleep and how it works, discuss why many people suffer from sleep deprivation without knowing it, and offer practical tips for getting better sleep, falling asleep fast, and having more energy.
How much sleep do you really need? To answer that question, let's consider an experiment conducted by researchers at the University of Pennsylvania and Washington State University.
Second, participants didn't notice their own performance declines. When participants graded themselves, they believed that their performance declined for a few days and then tapered off. In reality, they were continuing to get worse with each day. In other words, we are poor judges of our own performance decreases even as we are going through them. In the real world, well-lit office spaces, social conversations, caffeine, and a variety of other factors can make you feel fully awake even though your actual performance is sub-optimal. You might think that your performance is staying the same even on low amounts of sleep, but it's not. And even if you are happy with your sleep-deprived performance levels, you're not performing optimally.
Here's another way to say it: 95 percent of adults who get less than 7 hours of sleep on a routine basis will experience decreased mental and physical performance. According to Harvard Medical School, “The average length of time Americans spend sleeping has dropped from about nine hours a night in 1910 to about seven hours today.” And according to Dr. Lawrence Epstein at Harvard Medical School, 20 percent of Americans (1 in 5) get less than six hours of sleep per night.
There is no need to worry about optimizing how much REM or slow wave sleep you get. Your body is smarter than you are and because it makes adjustments based on previous sleep cycles, you can't really force yourself to get more REM sleep, for example, during a particular sleep session. All you can do is make sure you get enough sleep and then let your body do the rest. This is particularly important as you age because the percentage of time spent in REM and slow wave sleep decreases as you get older. As an example, a 60-year-old may need to sleep for 10 hours to get the same about of REM sleep that a 20-year-old can get in 7 hours. To put it simply: there is no substitute for sleeping.
Now that we understand how sleep works, let's talk about some practical strategies for getting better sleep.
Stop smoking or chewing tobacco. Tobacco use has been linked to a long line of health issues and poor sleep is another one on the list. I don't have any personal experience with tobacco use, but I have heard from friends who have quit successfully that Allen Carr's Easy Way to Stop Smoking book is the best resource on the topic.
If you want even more strategies for how to sleep better, check out my article 3 Ways to Improve Your Sleep.
Sound. A quiet space is key for good sleep. If peace and quiet is hard to come by, try controlling the bedroom noise by creating “white noise” with a fan. Or, use earplugs (here's a good pair).
Alcohol. This one is a slippery slope. It is true that having a drink before bed — a “night cap” — often does help people fall asleep fast. However, while it makes it easier to fall asleep, it actually reduces the quality of your sleep and delays the REM cycle. So you fall asleep faster, but it's possible that you'll wake up without feeling rested. It's probably best to improve your sleep through other methods before resorting to alcohol to do the job.
Use strategic naps. Generally speaking, one nap in the early afternoon is the best way to add napping to your sleep cycle. This is particularly useful if you aren't getting enough sleep each night as your body may be able to make up the deficit during your nap.
Cumulative sleep debt is robbing companies of billions of dollars in revenue. It's robbing individuals of sharper mental performance. It's preventing athletes from performing at their best. And it's a barrier between you and optimal performance.
The ideas in this article offer a variety approaches on how to get better sleep. If you're looking for more practical strategies on how to create better sleep habits (or better habits in general), then read my book Atomic Habits or browse my best articles on behavior change and habit formation.
Thanks to Sam Sager for his tireless help researching this article and to Scott Britton for his slideshow on sleep strategies.


The earliest recorded example of the use of an internal combustion engine in a railway locomotive is the prototype designed by William Dent Priestman, which was examined by Sir William Thomson in 1888 who described it as a "[Priestman oil engine] mounted upon a truck which is worked on a temporary line of rails to show the adaptation of a petroleum engine for locomotive purposes.". In 1894, a 20 hp (15 kW) two axle machine built by Priestman Brothers was used on the Hull Docks. In 1896 an oil-engined railway locomotive was built for the Royal Arsenal, Woolwich, England, in 1896, using an engine designed by Herbert Akroyd Stuart. It was not, strictly, a diesel because it used a hot bulb engine (also known as a semi-diesel) but it was the precursor of the diesel.
Following the expiration of Dr. Rudolf Diesel's patent in 1912, his engine design was successfully applied to marine propulsion and stationary applications. However, the massiveness and poor power-to-weight ratio of these early engines made them unsuitable for propelling land-based vehicles. Therefore, the engine's potential as a railroad prime mover was not initially recognized. This changed as development reduced the size and weight of the engine.
In 1906, Rudolf Diesel, Adolf Klose and the steam and diesel engine manufacturer Gebrüder Sulzer founded Diesel-Sulzer-Klose GmbH to manufacture diesel-powered locomotives. Sulzer had been manufacturing Diesel engines since 1898. The Prussian State Railways ordered a diesel locomotive from the company in 1909, and after test runs between Winterthur and Romanshorn the diesel–mechanical locomotive was delivered in Berlin in September 1912. The world's first diesel-powered locomotive was operated in the summer of 1912 on the Winterthur–Romanshorn railroad in Switzerland, but was not a commercial success. During further test runs in 1913 several problems were found. After the First World War broke out in 1914, all further trials were stopped. The locomotive weight was 95 tonnes and the power was 883 kW with a maximum speed of 100 km/h. Small numbers of prototype diesel locomotives were produced in a number of countries through the mid-1920s.
Adolphus Busch purchased the American manufacturing rights for the diesel engine in 1898 but never applied this new form of power to transportation. He founded the Busch-Sulzer company in 1911. Only limited success was achieved in the early twentieth century with internal combustion engined railcars, due, in part, to difficulties with mechanical drive systems.
General Electric (GE) entered the railcar market in the early twentieth century, as Thomas Edison possessed a patent on the electric locomotive, his design actually being a type of electrically propelled railcar. GE built its first electric locomotive prototype in 1895. However, high electrification costs caused GE to turn its attention to internal combustion power to provide electricity for electric railcars. Problems related to co-coordinating the prime mover and electric motor were immediately encountered, primarily due to limitations of the Ward Leonard current control system that had been chosen.
A significant breakthrough occurred in 1914, when Hermann Lemp, a GE electrical engineer, developed and patented a reliable direct current electrical control system (subsequent improvements were also patented by Lemp). Lemp's design used a single lever to control both engine and generator in a coordinated fashion, and was the prototype for all internal combustion–electric drive control systems.
In 1917–18, GE produced three experimental diesel–electric locomotives using Lemp's control design, the first known to be built in the United States. Following this development, the 1923 Kaufman Act banned steam locomotives from New York City because of severe pollution problems. The response to this law was to electrify high-traffic rail lines. However, electrification was uneconomical to apply to lower-traffic areas.
The first regular use of diesel–electric locomotives was in switching (shunter) applications, which were more forgiving than mainline applications of the limitations of contemporary diesel technology and where the idling economy of diesel relative to steam would be most beneficial. GE entered a collaboration with the American Locomotive Company (ALCO) and Ingersoll-Rand (the "AGEIR" consortium) in 1924 to produce a prototype 300 hp (220 kW) "boxcab" locomotive delivered in July 1925. This locomotive demonstrated that the diesel–electric power unit could provide many of the benefits of an electric locomotive without the railroad having to bear the sizeable expense of electrification. The unit successfully demonstrated, in switching and local freight and passenger service, on ten railroads and three industrial lines. Westinghouse Electric and Baldwin collaborated to build switching locomotives starting in 1929. However, the Great Depression curtailed demand for Westinghouse's electrical equipment, and they stopped building locomotives internally, opting to supply electrical parts instead.
In June 1925, Baldwin Locomotive Works outshopped a prototype diesel–electric locomotive for "special uses" (such as for runs where water for steam locomotives was scarce) using electrical equipment from Westinghouse Electric Company. Its twin-engine design was not successful, and the unit was scrapped after a short testing and demonstration period. Industry sources were beginning to suggest “the outstanding advantages of this new form of motive power”. In 1929, the Canadian National Railways became the first North American railway to use diesels in mainline service with two units, 9000 and 9001, from Westinghouse. However, these early diesels proved expensive and unreliable, with their high cost of acquisition relative to steam unable to be realized in operating cost savings as they were frequently out of service. It would be another five years before diesel-electric propulsion would be successfully used in mainline service, and nearly ten years before it would show real potential to fully replace steam.
Before diesel power could make inroads into mainline service, the limitations of diesel engines circa 1930 - low power-to-weight ratios and narrow output range - had to be overcome. A major effort to overcome those limitations was launched by General Motors after they moved into the diesel field with their acquisition of the Winton Engine Company, a major manufacturer of diesel engines for marine and stationary applications, in 1930. Supported by the General Motors Research Division, GM's Winton Engine Corporation sought to develop diesel engines suitable for high speed mobile use. The first milestone in that effort was delivery in early 1934 of the Winton 201A, a two-stroke, Roots-blown, uniflow-scavenged, unit-injected diesel engine that could deliver the required performance for a fast, lightweight passenger train. The second milestone, and the one that got American railroads moving towards diesel, was the 1938 delivery of GM's Model 567 engine that was designed specifically for locomotive use, bringing a fivefold increase in life of some mechanical parts and showing its potential for meeting the rigors of freight service.
Diesel–electric railroad locomotion entered mainline service when the Burlington Railroad and Union Pacific used custom-built diesel "streamliners" to haul passengers, starting in late 1934.Burlington's Zephyr trainsets evolved from articulated three car sets with 600 hp power cars in 1934 and early 1935, to the Denver Zephyr semi-articulated ten car trainsets pulled by cab-booster power sets introduced in late 1936. Union Pacific started diesel streamliner service between Chicago and Portland Oregon in June 1935, and in the following year would add Los Angeles and Oakland California, and Denver Colorado to the destinations of diesel streamliners out of Chicago. The Burlington and Union Pacific streamliners were built by the Budd Company and the Pullman-Standard Company, respectively, using the new Winton engines and power train systems designed by GM's Electro-Motive Corporation. EMC's experimental 1800 hp B-B locomotives of 1935 demonstrated the multiple-unit control systems used for the cab/booster sets and the twin engine format used with the later Zephyr power units. Both of those features would be used in EMC's later production model locomotives. The lightweight diesel streamliners of the mid-1930s demonstrated the advantages of diesel for passenger service with breakthrough schedule times, but diesel locomotive power would not fully come of age until regular series production of mainline diesel locomotives commenced and it was shown suitable for full-size passenger and freight service.
Following their 1925 prototype, the AGEIR consortium produced 25 more units of 300 hp (220 kW) "60 ton" AGEIR boxcab switching locomotives between 1925 and 1928 for several New York City railroads, making them the first series-produced diesel locomotives.  The consortium also produced seven twin-engine "100 ton" boxcabs and one hybrid trolley/battery unit with a diesel-driven charging circuit. ALCO acquired the McIntosh & Seymour Engine Company in 1929 and entered series production of 300 hp (220 kW) and 600 hp (450 kW) single-cab switcher units in 1931. ALCO would be the pre-eminent builder of switch engines through the mid-1930s and would adapt the basic switcher design to produce versatile and highly successful, albeit relatively low powered, road locomotives.
GM, seeing the success of the custom streamliners, sought to expand the market for diesel power by producing standardized locomotives under their Electro-Motive Corporation. In 1936 EMC's new factory started production of switch engines. In 1937 the factory started producing their new E series streamlined passenger locomotives, which would be upgraded with more reliable purpose-built engines in 1938. Seeing the performance and reliability of the new 567 model engine in passenger locomotives, EMC was eager to demonstrate diesel's viability in freight service.
Following the successful 1939 tour of EMC's FT demonstrator freight locomotive set, the stage was set for dieselization of American railroads. In 1941 ALCO-GE introduced the RS-1 road-switcher that occupied its own market niche while EMD's F series locomotives were sought for mainline freight service. The US entry into World War II slowed conversion to diesel; the War Production Board put a halt to building new passenger equipment and gave naval uses priority for diesel engine production. During the petroleum crisis of 1942-43, coal-fired steam had the advantage of not using fuel that was in critically short supply. EMD was later allowed to increase production of its FT locomotives and ALCO-GE was allowed to produce a limited number of DL-109 road locomotives, but most in the locomotive business were restricted to making switch engines and steam locomotives.
In the early postwar era, EMD dominated the market for mainline locomotives with their E and F series locomotives. ALCO-GE in the late 1940s produced switchers and road-switchers that were successful in the short-haul market. However, EMD launched their GP series road-switcher locomotives in 1949, which displaced all other locomotives in the freight market including their own F series locomotives. GE subsequently dissolved its partnership with ALCO and would emerge as EMD's main competitor in the early 1960s, eventually taking the top position in the locomotive market from EMD.
Early diesel–electric locomotives in the United States used direct current (DC) traction motors, but alternating current (AC) motors came into widespread use in the 1990s, starting with the Electro-Motive SD70MAC in 1993 and followed by the General Electric's AC4400CW in 1994 and AC6000CW in 1995.
In 1914, world's first functional diesel–electric railcars were produced for the Königlich-Sächsische Staatseisenbahnen (Royal Saxon State Railways) by Waggonfabrik Rastatt with electric equipment from Brown, Boveri & Cie and diesel engines from Swiss Sulzer AG. They were classified as DET 1 and DET 2 (de.wiki). Due to shortage of petrol products during World War I, they remained unused for regular service in Germany. In 1922, they were sold to Swiss Compagnie du Chemin de fer Régional du Val-de-Travers (fr.wiki), where they were used in regular service up to the electrification of the line in 1944. Afterwards, the company kept them in service as boosters till 1965.
The engine Ээл2 (Eel2 original number Юэ 001/Yu-e 001) started on October 22. It had been designed by a team led by Yuri Lomonosov and built 1923–1924 by Maschinenfabrik Esslingen in Germany. It had 5 driving axles (1'E1'). After several test rides, it hauled trains for almost three decades from 1925 to 1954. Though proved to be world's first functional diesel locomotive, it did not become a series, but it became a model for several classes of Soviet diesel locomotives.
The engine Щэл1 (Shch-el 1, original number Юэ2/Yu-e 2), started on November 9. It had been developed by Yakov Modestovich Gakkel (ru.wiki) and built by Baltic Shipyard in Saint Petersburg. It had ten driving axles in three bogies (1' Co' Do' Co' 1'). From 1925 to 1927, it hauled trains between Moscow and Kursk and in Caucasus region. Due to technical problems, afterwards it was out of service. Since 1934, it was used as a stationary electric generator.
Diesel-powered or "oil-engined" railcars, generally diesel–mechanical, were developed by various European manufacturers in the 1930s, e.g. by William Beardmore and Company for the Canadian National Railways (the Beardmore Tornado engine was subsequently used in the R101 airship). Some of those series for regional traffic were begun with gasoline motors and then continued with diesel motors, such as Hungarian BCmot (The class code doesn't tell anything but "railmotor with 2nd and 3rd class seats".), 128 cars built 1926 – 1937, or German Wismar railbuses (57 cars 1932 – 1941). In France, the first diesel railcar was Renault VH, 115 units produced 1933/34. In Italy, after 6 Gasoline cars since 1931, Fiat and Breda built a lot of diesel railmotors, more than 110 from 1933 to 1938 and 390 from 1940 to 1953, Class 772 known as Littorina, and Class ALn 900.
In Germany, the Flying Hamburger was built in 1932. After a test ride in December 1932, this two coach diesel railcar (in English terminology a DMU2) started service at Deutsche Reichsbahn (DRG) in February 1933. It became the prototype of DRG Class SVT 137 with 33 more highspeed DMUs, built for DRG till 1938, 13 DMU 2 ("Hamburg" series), 18 DMU 3 ("Leipzig" and "Köln" series), and 2 DMU 4 ("Berlin" series).
In 1945, a batch of 30 Baldwin diesel–electric locomotives, Baldwin 0-6-6-0 1000, was delivered from the United States to the railways of the Soviet Union.
In 1947, the London Midland & Scottish Railway introduced the first of a pair of 1,600 hp (1,200 kW) Co-Co diesel–electric locomotives (later British Rail Class D16/1) for regular use in the United Kingdom, although British manufacturers such as Armstrong Whitworth had been exporting diesel locomotives since 1930. Fleet deliveries to British Railways, of other designs such as Class 20 and Class 31, began in 1957.
One of the first home developed diesel vehicles of China was the DMU Dongfeng (东风), produced in 1958 by CSR Sifang. Series production of China's first diesel locomotive class, the DFH 1, began in 1964 following construction of a prototype in 1959.
The Trans-Australian Railway built 1912 to 1917 by Commonwealth Railways (CR) passes through 2000 km of waterless (or salt watered) desert terrain unsuitable for steam locomotives. The original engineer Henry Deane envisaged diesel operation to overcome such problems. Some have suggested that the CR worked with the South Australian Railways to trial diesel traction. However, the technology was not developed enough to be reliable.
Some Australian railway companies bought McKeen railcars.
High speed vehicles for those days' possibilities on 3 ft 6 in (1,067 mm) were the 10 Vulcan railcars of 1940 for New Zealand.
A diesel–mechanical locomotive uses a mechanical transmission in a fashion similar to that employed in most road vehicles. This type of transmission is generally limited to low-powered, low speed shunting (switching) locomotives, lightweight multiple units and self-propelled railcars.
A British Rail Class 03 diesel–mechanical shunter with a jackshaft under the cab.
The mechanical transmissions used for railroad propulsion are generally more complex and much more robust than standard-road versions. There is usually a fluid coupling interposed between the engine and gearbox, and the gearbox is often of the epicyclic (planetary) type to permit shifting while under load. Various systems have been devised to minimise the break in transmission during gear changing; e.g., the S.S.S. (synchro-self-shifting) gearbox used by Hudswell Clarke.
Diesel–mechanical propulsion is limited by the difficulty of building a reasonably sized transmission capable of coping with the power and torque required to move a heavy train. A number of attempts to use diesel–mechanical propulsion in high power applications have been made (e.g., the 1,500 kW (2,000 hp) British Rail 10100 locomotive), although none have proved successful in the end.
For locomotives powered by a combination of diesel or fuel cells and batteries or ultracapacitors, see hybrid train.
In a diesel–electric locomotive, the diesel engine drives either an electrical DC generator (generally, less than 3,000 horsepower (2,200 kW) net for traction), or an electrical AC alternator-rectifier (generally 3,000 horsepower (2,200 kW) net or more for traction), the output of which provides power to the traction motors that drive the locomotive. There is no mechanical connection between the diesel engine and the wheels.
The EMD F40PH (left) and MPI MPXpress-series MP36PH-3S (right) locomotives coupled together by Metra use diesel–electric transmission.
A diesel–electric locomotive's power output is independent of road speed, as long as the unit's generator current and voltage limits are not exceeded. Therefore, the unit's ability to develop tractive effort (also referred to as drawbar pull or tractive force, which is what actually propels the train) will tend to inversely vary with speed within these limits. (See power curve below). Maintaining acceptable operating parameters was one of the principal design considerations that had to be solved in early diesel–electric locomotive development and, ultimately, led to the complex control systems in place on modern units.
Locomotive power output, and thus speed, is typically controlled by the engine driver using a stepped or "notched" throttle that produces binary-like electrical signals corresponding to throttle position. This basic design lends itself well to multiple unit (MU) operation by producing discrete conditions that assure that all units in a consist respond in the same way to throttle position. Binary encoding also helps to minimize the number of trainlines (electrical connections) that are required to pass signals from unit to unit. For example, only four trainlines are required to encode all possible throttle positions.
North American locomotives, such as those built by EMD or General Electric, have nine throttle positions, one idle and eight power (as well as an emergency stop position that shuts down the prime mover). Many UK-built locomotives have a ten-position throttle. The power positions are often referred to by locomotive crews as "run 3" or "notch 3", depending upon the throttle setting.
As will be seen in the following discussion, the propulsion system is designed to produce maximum traction motor torque at start-up, which explains why modern locomotives are capable of starting trains weighing in excess of 15,000 tons, even on ascending grades. Current technology allows a locomotive to develop as much as 30 percent of its loaded driver weight in tractive force, amounting to some 120,000 pounds-force (530 kN) of drawbar pull for a large, six-axle freight (goods) unit. In fact, a consist of such units can produce more than enough drawbar pull at start-up to damage or derail cars (if on a curve) or break couplers (the latter being referred to in North American railroad slang as "jerking a lung"). Therefore, it is incumbent upon the engine driver to carefully monitor the amount of power being applied at start-up to avoid damage. In particular, "jerking a lung" could be a calamitous matter if it were to occur on an ascending grade, except that the safety inherent in the correct operation of automatic train brakes installed in wagons today, prevents runaway trains by automatically applying the wagon brakes when train line air pressure drops.
A locomotive's control system is designed so that the main generator electrical power output is matched to any given engine speed. Given the innate characteristics of traction motors, as well as the way in which the motors are connected to the main generator, the generator will produce high current and low voltage at low locomotive speeds, gradually changing to low current and high voltage as the locomotive accelerates. Therefore, the net power produced by the locomotive will remain constant for any given throttle setting (see power curve graph for notch 8).
In older designs, the prime mover's governor and a companion device, the load regulator, play a central role in the control system. The governor has two external inputs: requested engine speed, determined by the engine driver's throttle setting, and actual engine speed (feedback). The governor has two external control outputs: fuel injector setting, which determines the engine fuel rate, and load regulator position, which affects main generator excitation. The governor also incorporates a separate overspeed protective mechanism that will immediately cut off the fuel supply to the injectors and sound an alarm in the cab in the event the prime mover exceeds a defined RPM. Not all of these inputs and outputs are necessarily electrical.
The load regulator is essentially a large potentiometer that controls the main generator power output by varying its field excitation and hence the degree of loading applied to the engine. The load regulator's job is relatively complex, because although the prime mover's power output is proportional to RPM and fuel rate, the main generator's output is not (which characteristic was not correctly handled by the Ward Leonard elevator- and hoist-type drive system that was initially tried in early locomotives). Instead, a quite complex electro-hydraulic Woodward governor was employed. Today, this important function would be performed by the Engine control unit, itself being a part of the Locomotive control unit.
In newer designs controlled by a “traction computer,” each engine speed step is allotted an appropriate power output, or “kW reference”, in software. The computer compares this value with actual main generator power output, or “kW feedback”, calculated from traction motor current and main generator voltage feedback values. The computer adjusts the feedback value to match the reference value by controlling the excitation of the main generator, as described above. The governor still has control of engine speed, but the load regulator no longer plays a central role in this type of control system. However, the load regulator is retained as a “back-up” in case of engine overload. Modern locomotives fitted with electronic fuel injection (EFI) may have no mechanical governor; however a “virtual” load regulator and governor are retained with computer modules.
At standstill, main generator output is initially low voltage/high current, often in excess of 1000 amperes per motor at full power. When the locomotive is at or near standstill, current flow will be limited only by the DC resistance of the motor windings and interconnecting circuitry, as well as the capacity of the main generator itself. Torque in a series-wound motor is approximately proportional to the square of the current. Hence, the traction motors will produce their highest torque, causing the locomotive to develop maximum tractive effort, enabling it to overcome the inertia of the train. This effect is analogous to what happens in an automobile automatic transmission at start-up, where it is in first gear and thus producing maximum torque multiplication.
As the locomotive accelerates, the now-rotating motor armatures will start to generate a counter-electromotive force (back EMF, meaning the motors are also trying to act as generators), which will oppose the output of the main generator and cause traction motor current to decrease. Main generator voltage will correspondingly increase in an attempt to maintain motor power, but will eventually reach a plateau. At this point, the locomotive will essentially cease to accelerate, unless on a downgrade. Since this plateau will usually be reached at a speed substantially less than the maximum that may be desired, something must be done to change the drive characteristics to allow continued acceleration. This change is referred to as "transition," a process that is analogous to shifting gears in an automobile.
Reconnecting the two separate internal main generator stator windings of two rectifiers from parallel to series to increase the output voltage.
In older locomotives, it was necessary for the engine driver to manually execute transition by use of a separate control. As an aid to performing transition at the right time, the load meter (an indicator that shows the engine driver how much current is being drawn by the traction motors) was calibrated to indicate at which points forward or backward transition should take place. Automatic transition was subsequently developed to produce better operating efficiency and to protect the main generator and traction motors from overloading from improper transition.
A common option on diesel–electric locomotives is dynamic (rheostatic) braking.
The armature of each traction motor is connected across a forced-air-cooled resistance grid (the dynamic braking grid) in the roof of the locomotive's hood.
Dynamic braking is particularly beneficial when operating in mountainous regions; where there is always the danger of a runaway due to overheated friction brakes during descent. In such cases, dynamic brakes are usually applied in conjunction with the air brakes, the combined effect being referred to as blended braking. The use of blended braking can also assist in keeping the slack in a long train stretched as it crests a grade, helping to prevent a "run-in", an abrupt bunching of train slack that can cause a derailment. Blended braking is also commonly used with commuter trains to reduce wear and tear on the mechanical brakes that is a natural result of the numerous stops such trains typically make during a run.
Metro-North's GE Genesis P32AC-DM electro-diesel locomotive can also operate off of third-rail electrification.
These special locomotives can operate as an electric locomotive or as a diesel locomotive. The Long Island Rail Road, Metro-North Railroad and New Jersey Transit Rail Operations operate dual-mode diesel–electric/third-rail (catenary on NJTransit) locomotives between non-electrified territory and New York City because of a local law banning diesel-powered locomotives in Manhattan tunnels. For the same reason, Amtrak operates a fleet of dual-mode locomotives in the New York area. British Rail operated dual diesel–electric/electric locomotives designed to run primarily as electric locomotives with reduced power available when running on diesel power. This allowed railway yards to remain un-electrified, as the third rail power system is extremely hazardous in a yard area.
Hydraulic drive systems using a hydrostatic hydraulic drive system have been applied to rail use. Modern examples included 350 to 750 hp (260 to 560 kW) shunting locomotives by CMI Group (Belgium), 4 to 12 tonne 35 to 58 kW (47 to 78 hp) narrow gauge industrial locomotives by Atlas Copco subsidiary GIA. Hydrostatic drives are also utilised in railway maintenance machines (tampers, rail grinders).
Application of hydrostatic transmissions is generally limited to small shunting locomotives and rail maintenance equipment, as well as being used for non-tractive applications in diesel engines such as drives for traction motor fans.
British Rail diesel–hydraulic locomotives: Class 52 "Western", Class 42 "Warship" and Class 35 "Hymek"
Diesel–hydraulic locomotives are less efficient than diesel–electrics. The first-generation BR diesel hydraulics were significantly less efficient (c. 65%) than diesel electrics (c. 80%) — moreover initial versions were found in many countries to be mechanically more complicated and more likely to break down. Hydraulic transmission for locomotives was developed in Germany. There is still debate over the relative merits of hydraulic vs. electrical transmission systems: advantages claimed for hydraulic systems include lower weight, high reliability, and lower capital cost.
In Germany and Finland, diesel–hydraulic systems have achieved high reliability in operation. In the UK the diesel–hydraulic principle gained a poor reputation due to the poor durability and reliability of the Maybach Mekydro hydraulic transmission. Argument continues over the relative reliability of hydraulic systems, with questions over whether data has been manipulated to favour local suppliers over non-German ones.
Diesel–hydraulic drive is common in multiple units, with various transmission designs used including Voith torque converters, and fluid couplings in combination with mechanical gearing.
The majority of British Rail's second generation passenger DMU stock used hydraulic transmission. In the 21st century designs using hydraulic transmission include Bombardier's Turbostar, Talent, RegioSwinger families; diesel engined versions of Siemens's Desiro platform, and the Stadler Regio-Shuttle.
Other main-line locomotives of the post war period included the 1950s GMD GMDH-1 experimental locomotives; the Henschel & Son built South African Class 61-000; in the 1960s Southern Pacific bought 18 Krauss-Maffei KM ML-4000 diesel–hydraulic locomotives. The Denver & Rio Grande Western also bought three, all of which were later sold to SP.
In the 21st century series production standard gauge diesel–hydraulic designs include the Voith Gravita, ordered by Deutsche Bahn, and the Vossloh G2000, G1206 and G1700 designs, all manufactured in Germany for freight use.
The diesel-pneumatic locomotive was of interest in the 1930s because it offered the possibility of converting existing steam locomotives to diesel operation. The frame and cylinders of the steam locomotive would be retained and the boiler would be replaced by a diesel engine driving an air compressor. The problem was low thermal efficiency because of the large amount of energy wasted as heat in the air compressor. Attempts were made to compensate for this by using the diesel exhaust to re-heat the compressed air but these had limited success. A German proposal of 1929 did result in a prototype but a similar British proposal of 1932, to use an LNER Class R1 locomotive, never got beyond the design stage.
Most diesel locomotives are capable of multiple unit operation (MU) as a means of increasing horsepower and tractive effort when hauling heavy trains. All North American locomotives, including export models, use a standardized AAR electrical control system interconnected by a 27-pin jumper cable between the units. For UK-built locomotives, a number of incompatible control systems are used, but the most common is the Blue Star system, which is electro-pneumatic and fitted to most early diesel classes. A small number of types, typically higher-powered locomotives intended for passenger only work, do not have multiple control systems. In all cases, the electrical control connections made common to all units in a consist are referred to as trainlines. The result is that all locomotives in a consist behave as one in response to the engine driver's control movements.
The ability to couple diesel–electric locomotives in an MU fashion was first introduced in the EMD FT four-unit demonstrator that toured the United States in 1939. At the time, American railroad work rules required that each operating locomotive in a train had to have on board a full crew. EMD circumvented that requirement by coupling the individual units of the demonstrator with drawbars instead of conventional knuckle couplers and declaring the combination to be a single locomotive. Electrical interconnections were made so one engine driver could operate the entire consist from the head-end unit. Later on, work rules were amended and the semi-permanent coupling of units with drawbars was eliminated in favour of couplers, as servicing had proved to be somewhat cumbersome owing to the total length of the consist (about 200 feet or nearly 61 meters).
In mountainous regions, it is common to interpose helper locomotives in the middle of the train, both to provide the extra power needed to ascend a grade and to limit the amount of stress applied to the draft gear of the car coupled to the head-end power. The helper units in such distributed power configurations are controlled from the lead unit's cab through coded radio signals. Although this is technically not an MU configuration, the behaviour is the same as with physically interconnected units.
Cab arrangements vary by builder and operator. Practice in the U.S. has traditionally been for a cab at one end of the locomotive with limited visibility if the locomotive is not operated cab forward. This is not usually a problem as U.S. locomotives are usually operated in pairs, or threes, and arranged so that a cab is at each end of each set. European practice is usually for a cab at each end of the locomotive as trains are usually light enough to operate with one locomotive. Early U.S. practice was to add power units without cabs (booster or B units) and the arrangement was often A-B, A-A, A-B-A, A-B-B, or A-B-B-A where A was a unit with a cab. Center cabs were sometimes used for switch locomotives.
In North American railroading, a cow-calf set is a pair of switcher-type locomotives: one (the cow) equipped with a driving cab, the other (the calf) without a cab, and controlled from the cow through cables. Cow-calf sets are used in heavy switching and hump yard service. Some are radio controlled without an operating engineer present in the cab. This arrangement is also known as master-slave. Where two connected units were present, EMD called these TR-2s (approximately 2,000 hp or 1,500 kW); where three units, TR-3s (approximately 3,000 hp or 2,200 kW).
A Canadian National Railway train showing the placement of the headlight and ditch lights on the locomotive.
The lights fitted to diesel locomotives vary from country to country. North American locomotives are fitted with two headlights (for safety in case one malfunctions) and a pair of ditch lights. The latter are fitted low down at the front and are designed to make the locomotive easily visible as it approaches a grade crossing. Older locomotives may be fitted with a Gyralite or Mars Light instead of the ditch lights.
Although diesel locomotives generally emit less sulphur dioxide, a major pollutant to the environment, and greenhouse gases than steam locomotives, they are not completely clean in that respect. Furthermore, like other diesel powered vehicles, they emit nitrogen oxides and fine particles, which are a risk to public health. In fact, in this last respect diesel locomotives may perform worse than steam locomotives.
For years, it was thought by American government scientists who measure air pollution that diesel locomotive engines were relatively clean and emitted far less health-threatening emissions than those of diesel trucks or other vehicles; however, the scientists discovered that because they used faulty estimates of the amount of fuel consumed by diesel locomotives, they grossly understated the amount of pollution generated annually (In Europe, where most major railways have been electrified, there is less concern). After revising their calculations, they concluded that the annual emissions of nitrogen oxide, a major ingredient in smog and acid rain, and soot would be by 2030 nearly twice what they originally assumed.
This would mean that diesel locomotives would be releasing more than 800,000 tons of nitrogen oxide and 25,000 tons of soot every year within a quarter of a century, in contrast to the EPA's previous projections of 480,000 tons of nitrogen dioxide and 12,000 tons of soot. Since this was discovered, to reduce the effects of the diesel locomotive on humans (who are breathing the noxious emissions) and on plants and animals, it is considered practical to install traps in the diesel engines to reduce pollution levels and other forms (e.g., use of biodiesel).
In 2008, the United States Environmental Protection Agency (EPA) mandated regulations requiring all new or refurbished diesel locomotives to meet Tier II pollution standards that slash the amount of allowable soot by 90% and require an 80% reduction in nitrogen oxide emissions. See List of low emissions locomotives.
Other technologies that are being deployed to reduce locomotive emissions and fuel consumption include "Genset" switching locomotives and hybrid Green Goat designs. Genset locomotives use multiple smaller high-speed diesel engines and generators (generator sets), rather than a single medium-speed diesel engine and a single generator. Because of the cost of developing clean engines, these smaller high-speed engines are based on already developed truck engines. Green Goats are a type of hybrid switching locomotive utilizing a small diesel engine and a large bank of rechargeable batteries. Switching locomotives are of particular concern as they typically operate in a limited area, often in or near urban centers, and spend much of their time idling. Both designs reduce pollution below EPA Tier II standards and cut or eliminate emissions during idle.
As diesel locomotives advanced, the cost of manufacturing and operating them dropped, and they became cheaper to own and operate than steam locomotives. In North America, steam locomotives were custom-made for specific railway routes, so economies of scale were difficult to achieve. Though more complex to produce with exacting manufacturing tolerances (1⁄10000-inch or 0.0025-millimetre for diesel, compared with 1⁄100-inch (0.25 mm) for steam), diesel locomotive parts were easier to mass produce. Baldwin Locomotive Works offered almost five hundred steam models in its heyday, while EMD offered fewer than ten diesel varieties.. In the United Kingdom, British Railways built steam locomotives to standard designs from 1951 onwards. These included standard, interchangeable parts, and were cheaper to produce than the diesel locomotives then available. The capital cost per drawbar horse power was £13 6s (steam), £65 (diesel), £69 7s (turbine) and £17 13s (electric).
Diesel locomotives offer significant operating advantages over steam locomotives. They can safely be operated by one person, making them ideal for switching/shunting duties in yards (although for safety reasons many main-line diesel locomotives continue to have 2-man crews: an engineer and a conductor/switchman) and the operating environment is much more attractive, being quieter, fully weatherproof and without the dirt and heat that is an inevitable part of operating a steam locomotive. Diesel locomotives can be worked in multiple with a single crew controlling multiple locomotives in a single train — something not practical with steam locomotives. This brought greater efficiencies to the operator, as individual locomotives could be relatively low-powered for use as a single unit on light duties but marshaled together to provide the power needed on a heavy train. With steam traction a single very powerful and expensive locomotive was required for the heaviest trains or the operator resorted to double heading with multiple locomotives and crews, a method which was also expensive and brought with it its own operating difficulties.
Steam engines required large quantities of coal and water, which were expensive variable operating costs. Further, the thermal efficiency of steam was considerably less than that of diesel engines. Diesel's theoretical studies demonstrated potential thermal efficiencies for a compression ignition engine of 36% (compared with 6–10% for steam), and an 1897 one-cylinder prototype operated at a remarkable 26% efficiency.
By the mid-1960s, diesel locomotives had effectively replaced steam locomotives where electric traction was not in use. Attempts to develop advanced steam technology continue in the 21st century but have not made a significant impact.
^ Churella 1998, p. 15.
^ a b Stover, John F. (1997). American Railroads. Chicago, Illinois: The University of Chicago Press. p. 212. ISBN 978-0-226-77658-3.
^ Edison, Thomas A. U.S. Patent No. 493,425, filed January 19, 1891, and issued March 14, 1891 Accessed via the Edison Papers at: US Patent #493,425 on February 8, 2007.
^ Churella 1998, pp. 25-27.
^ Churella 1998, p. 27.
^ a b Kettering, E.W. (29 November 1951). History and Development of the 567 Series General Motors Locomotive Engine (PDF). ASME 1951 Annual Meeting. Atlantic City, New Jersey: Electro-Motive Division, General Motors Corporation. Retrieved 6 January 2015.
^ Pinkepank 1973, p. 209–211.
^ "vecchia loco ferrovie della Calabria - Ferrovie.it". www.ferrovie.it.
^ "The first russian diesel locos". izmerov.narod.ru.
^ "DD50 5　DD50 2｜随時アップ：消えた車輌写真館｜鉄道ホビダス". rail.hobidas.com.
^ "A German Diesel-Pneumatic Locomotive". Douglas-self.com. Retrieved 2011-08-20.
^ "Development of the Flameproof Diesel Vehicle Applied New Exhaust Gas Dry Type Treatment System". Sciencelinks.jp. 2009-03-18. Archived from the original on 2012-02-17. Retrieved 2011-08-20.
^ King, Joe (2008-09-22). "Engineering gets $1 million grant to make locomotives leaner, greener". Northern Illinois University. Archived from the original on 2012-09-10. Retrieved 2011-08-06.
^ Eilperin, Juliet (2006-08-14). "Attention to Locomotives' Emissions Renewed". Washington Post. Retrieved 2011-08-06.
^ Hawthorne, Michael (February 14, 2011). "Metra finds 'alarming' pollution on some trains". Chicago Tribune. Retrieved 2011-08-06.
^ Wilkins, Davell (2011-04-13). "Study: Installed Traps In Diesel Engines Reduce Pollution Levels". Top News. Retrieved 2011-08-06.
^ "Pollution on Metra Trains Worse Than Thought: Report". Fox Chicago News. 2011-02-14. Retrieved 2011-08-06.
^ Lydersen, Kari (April 21, 2011). "Black Carbon Testing Finds High Levels". The New York Times. Retrieved August 6, 2011.
^ "Multi-Engine GenSet Ultra Low Emissions Road-Switcher Locomotive" (PDF). National Railway Equipment Company. Retrieved 2012-06-03.
^ "Railpower Technologies Products". Archived from the original on January 14, 2008. Retrieved 2012-06-03.
^ RJ Corman Railpower Genset & Hybrid Switchers. Trainweb.org. Retrieved on 2013-08-16.
^ Churella 1998, p. 10.
^ Churella 1998, p. 19.
^ SmartStart® IIe - Automatic Engine Start/Stop System. Ztr.com. Retrieved on 2013-08-16.
^ Churella 1998, pp. 12-17.
^ Churella 1998, p. 14.
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Is it possible to work full time and earn my master's degree?
Yes. Many CU graduate students are working professionals with full or part time jobs. Classes are offered in a variety of formats to accommodate busy schedules. A list of course formats for each degree program is listed below.
This will vary by enrollment status and program. Generally, students will complete their coursework in 2-3 years if they attend full time. Classes are available in fall, spring and summer sessions. Your graduate advisor will work with you to create a course schedule to help you stay on track.
I may need to take a semester or two off; how long do I have to finish my degree?
You have up to 6 years to complete your degree and all program requirements. If you take off for a full academic year, you will need to reapply and meet the current academic requirements prior to readmission.
Can I still pursue a degree I'm interested in if I don't have a bachelor's degree in that field?
Cameron's master's programs were designed for current practitioners and for those who don't have a bachelor's in a specific field; however, some of the degrees are more specialized and require alternative certifications prior to beginning the program or provide an option for completing various pre-requisite courses. To learn about which degrees apply, please feel free to request more information about your degree of interest.
I'm not sure I'll do well in online classes; how do they differ from a traditional class setting?
Just like a traditional classroom, the teaching style of each instructor will differ. You will do well if you remember to be self-disciplined and schedule your study time, carefully read and follow instructions, learn and understand the technology used, participate, follow university policies, and seek assistance when needed.
Are there financial assistance options available to graduate students?
While Cameron keeps tuition and fees low, various financial assistance options such as grants, loans, scholarships, tuition waivers, and educational benefits (often available through employers) are also available to graduate students. Please feel free to request more information to learn about options specific to your degree of interest.
I'm still working on my bachelor's degree; how can I start working on my master's now?
If you are within 16 hours of completing your bachelor's degree, you may pursue graduate study upon admission and completion of a degree audit with the registrar's office at your current institution. Please visit the "Application Process" section to learn about the proper documentation required for this process as well as to review the mailing address to use for sending these items.
I started a master's degree at another school but didn't finish; is it possible to transfer those credits?
Upon completing at least 12 graduate credit hours at Cameron, you may apply with the Dean of your school to request up to 12 graduate credit hours to be transferred to Cameron.


NEW YORK - An emotional and defiant Serena Williams argued she had been treated differently by umpire Carlos Ramos than a man would have been in the same situation, following the pair's stunning row in the final of the US Open.
Williams was beaten 6-2, 6-4 by Naomi Osaka, but the 20-year-old's historic triumph - the first by a Japanese player in a grand slam singles final - was sadly overshadowed on a truly remarkable evening in New York.
After conceding the first set, Williams took furious objection to receiving a code violation for coaching from umpire Ramos early in the second, angrily telling him: "I don't cheat to win. I'd rather lose."
Yet that was just the beginning of the drama as the 23-time slam singles champion, who remains one shy of Margaret Court's record haul, then earned a point penalty for racket abuse before being sensationally docked a game after she had continued to berate Ramos, calling the official a "thief".
For his part, Williams' coach Patrick Mouratoglou admitted he had passed messages to Williams, while arguing all coaches do likewise. Yet the Frenchman said he did not think Williams had looked at him and Serena insisted: "I wasn't being coached."
In a tense news conference, Williams was asked if she would do anything differently with the power to go back in time.
"I don't know. You definitely can't go back in time. I can't sit here and say I wouldn't say he (Ramos) is a thief, because I thought he took a game from me," she responded. "He alleged that I was cheating, and I wasn't cheating.
"But I've seen other men call other umpires several things. I'm here fighting for women's rights and for women's equality and for all kinds of stuff. For me to say 'thief' and for him to take a game, it made me feel like it was a sexist remark. He's never taken a game from a man because they said 'thief'."
Williams went on to reference a controversy earlier in the tournament, when Alize Cornet earned a violation for removing her shirt on court, although in that case tournament organizers subsequently apologized.
"For me it blows my mind. But I'm going to continue to fight for women and to fight for us to have equal (rights) ... like Cornet should be able to take off her shirt without getting a fine. This is outrageous," an unrepentant Williams continued. Cornet was not actually fined.
Before leaving the room, to a smattering of applause, she added: "I just feel like the fact that I have to go through this is just an example for the next person that has emotions, and that wants to express themselves, and wants to be a strong woman.


Are Americans Afraid to Talk About Their Faith Online?
On social networks like Twitter and Facebook, few regularly mention their religious beliefs.
Professions of faith are never not a big deal. Even preachers and imams and rabbis, who get paid to talk about God, share something intensely personal when they talk about their religious beliefs. Most faith traditions have rituals dedicated to declaring, this is what I believe: Catholics repeat the Nicene creed; Muslims recite the shahadah; Jews say the sh'ma.
All of which feel very different, of course, from #godtweets.
It's so casual: With 140 characters and the click of a button, anyone can declare their fundamental beliefs about the metaphysical nature of the universe. It's a little disorienting to think of any tweet in the same category as a formal religious ritual—being in church feels very different from scrolling through a newsfeed full of selfies and emojis.
But really, faith-related tweets and Facebook and Instagram posts are just a tech-y form of witnessing: When people share their beliefs publicly, they're affirming their own faith and offering it up to their community. Every part of life has its echo in social media; why should religion be any different? Just as some people choose to trumpet their baby announcements or relationship status on Facebook, so some choose to tweet their daily thanks to God.
But according to a new report from Pew, the way people talk about their faith online actually is different from how they talk about it in real life. In a nationally representative survey of more than 3,200 Americans, only 20 percent said they had "shared something about [their] religious faith on social networking websites/apps" in the past week. Twice as many said they had talked about faith in person within the same period.
Although people from different religious backgrounds reported different levels of what one might call faith-sharing, this relationship between on- and offline sharing was roughly the same across Christian denominations and the religiously unaffiliated: Twice as many people talked about their religious beliefs offline vs. online.
Perhaps the most interesting thing about this is that there's hardly any variation among age groups: People younger and older than 50 were nearly equally likely to say they'd talked about their faith on social media within the last week. That's remarkable for two reasons: In general, younger Americans are less religious than older Americans, and they're also much heavier users of social media. Across two demographics who think about both faith and the Internet very differently, the mores of talking about God online seem to be similar.
This survey doesn't say much what those mores are. But it does suggest that people like talking about their religious beliefs face-to-face more than they do online—or, perhaps, they're more willing. Broadcasting your faith to all your Facebook friends is a very public act, and religion is a very personal thing; it may be that people feel more comfortable discussing God in communities that exist offline, like youth groups or book clubs. These spaces can feel much less vulnerable: It's possible to know exactly who will hear you and maybe even have a sense of how they'll respond. On Facebook or Twitter, that's impossible.
It's not that faith and technology don't mix. The Bible app YouVersion has been downloaded more than 157 million times since the company was founded in 2008; by comparison, Instagram has 200 million monthly users.* But reading the Scriptures is private in a way that tweeting or using Facebook can never be, and perhaps that's why people are less likely to look to those kinds of networks as outlets for exploring their faith. Even offline, the social rules that govern how people talk about faith are complex; online, those rules are mediated through layers of irony, exposure—and, potentially, judgment.
* This article originally misstated the name of the Bible app YouVersion. We regret the error.


Sometimes trust is broken in a relationship. How do you repair broken trust? Unfortunately, there is no sure-fire solution. Consider one of the following strategies.
People want to be heard. Letting people vent and blow off their steam does not mean you agree with them. It just means you are listening. So, let the person who feels wronged tell his side of the story. You don't have to agree; you just have to listen. Check to make sure you understand by summarizing what the other is saying. Ask the counterparty if you've got his side of the story straight.
You don't have to agree; you just have to listen.


Tamworth's Chaffey Dam is the focus of a three-year, cooperative effort to unravel, understand, and devise ways of managing the mechanisms that cause blue-green algal blooms in warm-climate water storages. Through a series of experiments at Chaffey Dam, researchers aim to discover why attempts to control algal blooms by mixing the water in lakes using a technique called artificial destratification have been largely unsuccessful. They believe the answer may lie in the interplay between physical processes controlling light availability to algae and chemical processes controlling the availability of nutrients.
Expertise gained by CSIRO scientists at Sarawak, Malaysia, has led to their involvement in a million-dollar project to assist in the conservation of Bangladesh's hilsa fishery. Most hilsa are caught using drift or gill nets from traditional, non-mechanised wooden boats. The fishery is an integral part of the economy and social life of millions of people in Bangladesh, so it is vital that overfishing and pollution are controlled.
A study centred on seven open-cut coal mines in Queensland's Bowen Basin will help mining companies develop strategies to reduce the long-term impacts of their activities on the environment. Of concern is the quality and quantity of water entering the sites last excavated.
Two decades of ecological research drew to a close in May 1995 when CSIRO's Division of Wildlife and Ecology ceased managing Kapalga Research Station in the Kakadu National Park, NT. Kapalga has been at the forefront of research for conservation management in tropical Australia since its establishment by the Division in 1976. Studies have focused on the wildlife of Kakadu's wetlands, the impact of Asian water buffalo, and recently fire - the Top End's most contentious land management issue.
The Climate Variability Program, involving the CSIRO, Bureau of Meteorology, and other federal and state research agencies aims to contribute to climatic forecasts for events such as El Nino, so plans can be devised to manage the impact of climatic extremes.
Scientists at CSIRO and the Bureau of Meteorology Research Centre are working to develop an ocean-atmosphere model that simulates the El Nino-Southern Oscillation.
For over 30 years researchers have tried to simulate the world's climate by computer models that link oceanic and atmospheric processes. The difficulty in predicting sea-surface temperatures is one of many constraints that climate modellers are working to overcome. They also face complications such as: the influence of 'chaos'; the need for enormous computing power; variations in geographical scale; the difficulty of representing convection; and factors beyond the Pacific Basin that affect the climate system.
Computer models which generate predictions of long-term weather sequences are being used to aid studies of the behaviour of environmental systems that are climate-driven. This includes the impact of extreme weather events on large structures and cities, and processes such as erosion and water quality in lakes and streams.
The commercial fishing industry is as susceptible to the vagaries of climate variability as any farmer. An important outcome of climate variability models could be to help fisheries authorities understand the range of variability in marine ecosystems, and how this affects resource management.
Australia's forest industry, firefighting agencies, and natural disaster authorities have a mutual interest in improved forecasting of El Nino events. Researchers at the CSIRO Division of Forestry are attempting to tie better prediction of drought or significant rainfall events into information systems that would give fire-control agencies more time to plan for high-risk summers.
No industry sector in Australia feels the impact of drought earlier or more severely than agriculture. CSIRO's climate variability program aims, in the long term, to give rural communities reliable predictions of climate as far as three seasons ahead, and to develop tools to simplify decision-making. Farmers will use more reliable predictions of seasonal conditions to enhance their agronomic and economic decisions.
In Australia's arid zone the way graziers manage environmental climate variability can magnify or minimise the impact of grazing on the landscape. What makes management challenging is the diversity of climatic regimes in the rangelands.
Knowing what is likely to happen to the climate a season ahead could have profound impacts on the way farmers and graziers manage weeds, pests and diseases. Computer software that can predict the response of a plant or insect pest to short-term climate variation is being developed by CSIRO. The prediction will help state agriculture departments and farmers to devise better control strategies for particular weeds or pests thus minimising damage.
Changed fire regimes since European settlement have enabled tropical rainforest in northern Queensland to advance into wet schlerophyll habitat. The encroachment is affecting animals dependent on the sclerophyll forest and creating debate about appropriate management of the forest.
The book, Birds of South-western Australia, presents the results of a community-based observer scheme to map the distribution of birds in Western Australia's south-western agricultural area, to gauge numbers between 1987-1990, and to examine changes to their distribution and abundance this century. It also examines the major agents of change, and suggests ways of incorporating nature conservation into landscape management, so that declining birds may be protected.
A profile of entomologist Elwood Zimmerman, whose research work has culminated in the monumental 8 volume work, Australian Weevils.
The endangered Richmond birdwing butterfly has come under increasing pressure from the clearing of remnant rainforest verges in southern Queensland and northern New South Wales. 130 schools across the butterfly's former range, between Grafton and Maryborough, have been involved in planting the vine on which the butterfly depends. At the same time, community efforts to remove the imported Dutchman's pipe, which is toxic and poisons the emerging caterpillars which feed on it, are starting to have an impact.


Fund due diligence is much like startup diligence. It's about the team and strategy. And the odds are the same - LPs source a thousand fund opportunities, invest in a dozen, and get returns from a few. For LPs, due diligence begins and ends with the fund's investment team. The one question LP seeks to answer - Can this team generate strong returns?
Top-quartile managers with demonstrated & repeatable track records over fund cycles are sought after. Yet other LPs focus on emerging managers, who may bring fresh thinking. All fund-raising is at the mercy of markets. With Mr. Market on its side, even a mediocre group may have an oversubscribed fund.
§ Post-investment fund monitoring: Do both sides have the ability to build a transparent relationship?
While some seek to invest proven top-quartile established funds, others seek emerging managers. Some start the search with sectors and whittle down the universe of fund managers based on additional criteria. For LPs, the primary filter—performance—remains high on the list.
Lisa Edgar, managing director of Top Tier Capital Partners, a fund-of-funds prefers to start her screening process with performance. "In an environment defined by change, it is important to assess the fund manager's ability to produce superior returns across various technological and economic cycles," she says. A GP's ability to produce superior returns across various cycles is evident only after the venture firm has raised and invested a few funds. Georganne Perkins, managing director at Fisher Lynch Capital, a fund-of-funds seeks proven GPs as well. "A roman numeral V or higher is a good start," she points out. The "V" indicates the firm has invested capital over four previous fund cycles. Such a firm would have established a track record and a brand in the investment arena. Perkins, who formerly managed the PE investment portfolio at Stanford University, reviews over 200 fund documents, or private placement memorandums (PPMs), each year to invest in a handful of funds.
Most institutional investors typically see anywhere from 200 to 600 fund documents on a yearly basis. With such a high volume, the best way to stand above the ambient noise level is to begin a relationship via an introduction. Without a warm introduction, fund documents that come in the door cold often head for the trash can. But who makes the introduction is equally important. A trusted relationship, ideally another peer-level limited partner, an existing GP, or a respected attorney can make this path much easier. An inappropriate starting point could blow up this process very quickly.
"For state pension fund managers, getting calls from politicians is typical, including calls from the governor's office. Those who use pressure tactics, despite stellar performance, are starting with a deficit," says Robert "Bob" Clone, who served as director of private equity State of Michigan and Indiana retirement plans, managing over $50 billion in assets. Institutional investors often like to take it slow and warm up to a new fund manager over time, cautiously observing the fund's evolution and performance.
G. Thomas Doyal, managing director of global private equity investments for a family office, says, "We watch managers over several years and multiple investment cycles before we are ready to engage." Doyal, who sees about 50 fund documents each year, reviews them only after a strong relationship has been established with the investment team. "It is very unusual for us to look at anything cold," he says.
For newer managers, the ability to engage via an introduction and proactively build these potential institutional relationships is important. Providing meaningful updates on investments and performance can make the path easier. "Like any entrepreneur looking for the next best opportunity, we are always seeking the most promising managers—the Kleiner Perkins of the future,"advises Kenneth Van Heel, who manages $10 billion in assets as the head of the corporate pension fund for Dow Chemical Company.
Alex Bangash, an advisor to institutional LPs has found the best managers by watching for those who become magnets for smart entrepreneurs. “How desirable is a VC to entrepreneurs? Do they want your service?” he asks. Alex is the founder of Trusted Insight, an institutional investor platform for Alternatives, with over 60,000 LP members in 98 countries. A social network of LPs, Alex Bangash launched Trusted Insight to share LP expertise and due diligence across various sectors and geography.
Institutional investors evaluate venture firms on the two primary criteria: the fund managers' expertise and their investment strategy. Secondary criteria include investment terms and market conditions.
§ Fund managers' expertise. The foremost and primary criteria, limited partners seek to understand entrepreneurial / domain expertise. Performance is one of the foremost criteria.
§ Investment strategy. What is a fund's investment strategy, and how does it stand apart from the rest of venture funds? What unique factors / differentiators or "unfair advantage" does this combination of people and strategy bring to the VC arena?
In "What Drives Venture Capital Fund Raising?" authors Paul A. Gompers and Josh Lerner conclude that "Fund performance is an important determinant of the ability to raise new capital. Reputation, in the firm age and size, also positively impacts the ability to raise a new fund."
This theme, "performance is primary," recurs in various strands of academic literature. In a survey of investment criteria, over 200 U.S.-based LPs confirm the importance of performance. In order of priority, the LPs started with internal rate of return with a minimum floor of 12 percent and ideally closer to 30 percent to be considered for investment. The returns are also typically tied to a benchmark index for comparing performance. A performance of 400 basis points above the benchmark index, Russell 3000 or S&P 500 is often a threshold established by institutional investors. Other criteria included a consistent track record, diversification of the limited partners, team experience, and fund strategy.
In their book Beyond the J Curve, authors Thomas Meyer and Pierre-Yves Mathonet propose qualitative scoring criteria, which ranks the fund management team and fund strategy as the two top weighted factors, as shown below.
Considers the overall picture. For example, the fit between the team, fund size, and the strategy.
Source: Thomas Meyer and Pierre-Yves Mathonet, Beyond the J Curve—Managing a Portfolio of Venture Capital and Private Equity Funds (Chichester, UK: John Wiley & Sons, 2005), 221.
While all the listed criteria are important, Lisa Edgar of Top Tier Capital Partners asks a fundamental question - "Are we going to make money in this fund?"
Which pretty much sums it all up. It may be easier for a proven team to raise Fund V but what if you are just getting started? In my next post, we'll look at emerging managers - those who are on the path to raise Fund I.


My daughter is 16 years old. I have had a lot of problems with her. She thinks she's her own boss. She goes in and out of the house without permission. Finally, after a lot of things that I have tried with her, I told her that if she was going to do whatever she wants, do not ask me for nothing. She kept on doing the same behavior.
Last night, I called her at 2:30 am, first she told me she was on her way to the house. I called again around 3:00 and she said she was going at a friend's house that she will be home in 30 more minutes.
I got so mad, I told her that I was going to close the doors. She said, “fine I’ll sleep at one of my friend's house.” I said ok but it will be forever. When she asked why, I said “because you don't listen to me,” and I hung up the phone.
This morning I disconnected her cell. When I came back from work, she was here grabbing her clothes. This is not the first time that she leaves the house. I am so tired of her attitude. So, she left the house.
What do you think I should do next? This has been going on for almost 6 months now. I think I had tried everything, but she won't listen to nobody.
It sounds like you and your daughter are in a power struggle. Power struggles can create frustration, anger and resentment on the part of the parent and the child. Resentment can cause a further breakdown of communication until it seems as if all you do is argue.
In order to end such arguments, it must be the parent that begins to take charge in a positive way. However, the most effective step, to simply stop arguing, can also be the most difficult. It sounds quite simple, just stop arguing, but in reality, it takes discipline and effort to change the pattern of behavior. By refusing to participate in the argument, the power of the out-of-control child disappears. She only continues to have power over you if you allow her to.
To stop the power struggle, prepare yourself ahead of time. Sit down, after your daughter is in bed for the night and it is quiet, and make a list of the times that you most often argue. Is it getting ready for school, doing homework, completing chores, getting home on time, etc? For each situation, determine a few choices that you can give your kid.
When preparing the choices, make sure to list only those that you are willing to carry out. If you are not willing to pick up your daughter and bring her to school in her pajamas, don’t threaten to or she will know that she still has control of the situation.
Once you have decided on the choices you will give your out-of-control daughter, stick to them and practice your self-control to not yell. Walk away, leave the room, and wait outside if you have to. But an argument can only happen if there is more than one person. With just one person, it is simply a temper tantrum.
I think u did the right thing by disconnecting her cell phone. usually they dont get far without there phone. u can also call the police and they will bring her home or give her another choice. this usually works and scares them into knowing u mean business and she must follow your rules.
I could not handle my Daughter any more so I went to child support, she went to stay at one place but they to soon could not handle her & she not into going out she a scream and also does hit.The carer that she is with now has also had some bad times. But when she is good she is good but when she,s bad its World War 3. I have seen her afew times this year & the carer saids Iam a good parent even through at times I flet like a bad parent. Child support is there for both us Parents & the Child.
This is what you say to your daughter. By making the choice to stay out after curfew she makes the choice to not use the car. Period. Take the keys or remove the spark plugs if you have to. Give her a time frame to conduct proper behavior in order to get car privileges back.And if she argues you tell 'I'm not arguing'once only. Ignore after that.


Will Spotify build a smart speaker? The data is mixed.
You may have seen reports that Spotify is planning on getting into the hardware line, possibly with the goal of manufacturing their own smart speaker. After all, they compete with Apple and Amazon on the music streaming front; it only makes sense for them to offer their own music listening device as well.
So, is Spotify doing this to convince investors for their forthcoming IPO that they're not just a one-stream pony? Or is this a real effort to compete with Amazon and Apple? One of the advantages we have is: Access to a deep dive of data, not just a single data point. And looking at Spotify's hiring record as a whole we've gotta say, this does not look like a serious effort. At least not yet.
We are looking for a passionate and seasoned Senior Product Manager that will join the Platform & Partner Experience team working to build frictionless and creative Spotify experiences via fully-connected hardware devices. You will be leading an initiative to deliver hardware directly from Spotify to existing and new customers; a category defining product akin to Pebble Watch, Amazon Echo, and Snap Spectacles.
Remember Snap Spectacles? Of course you don't remember Snap Spectacles. They were a stunning $40 million dollar failure. Snap only managed to sell 150,000 of them (with millions more still sitting in warehouses, unsellable). But at the time, everyone speculated that Spotify was going to move into the wearable space, perhaps with a two-way wrist radio/ wireless streamer.
The speculation cropped up again over the past weeks, as a handful of new Spotify job listings hit. Coincidentally, Apple was launching their HomePod speaker. Coincidentally, Spotify was launching an IPO to raise $1 billion dollars.
So, let's examine the notion: Spotify will build a hardware smart-speaker to compete with Apple and Amazon.
We are looking for a passionate Senior Project Manager that will contribute in the creation of innovative Spotify experiences via connected hardware. You will be responsible for the overall hardware project delivery and work with suppliers to deliver the optimal Spotify experience to millions of users. Above all, your work will impact the way the world experiences music.
And pretty much the same listing applies to Project Manager Hardware Production (including most of the same verbiage).
Product Analyst – Hardware Products - but this one has a much more amorphous job description: "Work closely with cross-functional teams of user researchers, designers and engineers... You know how to understand and solve loosely defined problems and come up with relevant answers and actionable insights to guide product development decisions."
Senior Business Development Manager, Hardware - but this one looks like it's for integration with other companies' products: "We are looking for an excellent Business Development Manager that will focus specifically on developing and negotiating impactful strategic relationships with the key players in the Connected Devices space."
As we reported earlier today, Apple is piling on the Engineers... 1,270 hardware engineers. Here's our picture of Apple's hiring.
Okay, but how about overall job trends? Is there anything in the data that betrays a prospective Spotify Manhattan Project of hardware - of any kind?
Apple is notorious for building a beautiful, well-designed garden with high, high walls to keep out the competition. They kinda treat their users the way Krushchev treated East Berlin.
"...the speaker requires you have an iOS device to use it, and it demands an Apple Music account to make use of Siri-powered voice control playback. It is antithetical to platform-agnostic Sonos and unabashedly so, as if Apple is daring its competitors to try and compete with its hardware prowess and platform lock-in."
To be fair, you've gotta figure that anybody laying out $300 for Apple's baby boombox is probably already an Apple fanatic, and so not really Spotify's target audience in the first place. As @nickstatt continued, while he's tempted to go for the lustrous tones of the HomePOd, he's not going to abandon his 6 years' worth of Spotify playlists and user experience.
""Many of our competitors enjoy competitive advantages such as greater name recognition, legacy operating histories, and larger marketing budgets, as well as greater financial, technical, human, and other resources... Apple, Amazon, and Google, have developed, and are continuing to develop, devices for which their music streaming service is preloaded, creating a visibility advantage."
Hardware projects are notoriously hard, and ambitious attempts like Apple's HomePod are proof that even with loads of money and brainpower, first attempts at a new kind of product often feel unfinished. It could be years before the unprofitable Spotify starts to hit its stride in an industry it's unfamiliar with, and that's assuming the company has the guts to stick it out that long.
And writing at Hypebot, Bobby Owsinski sees an even bigger red flag for Spotify. They grew their services to #1 in the world on other people's platforms. How long will they be welcome there if they become direct competitors?
That all changes when Spotify becomes a gear manufacturer and that’s when we’ll start to see things get nasty, especially if the company’s market leadership begins to erode. You’ll start to see other hardware manufacturers make exclusive deals with other streaming networks, and you’ll see the big 3 (Apple, Amazon and Google) shut out Spotify from their own ecosystems.
On the other hand, Forbes' Parmy Olson takes the opposite approach. With smart speakers growing rapidly, and pushing a huge increase in music listening, Spotify has to provide its own hardware or die.
...half of all the music currently being streamed in the United States is being playing on the Amazon Echo or Google Home devices.... Meanwhile, if you like Spotify because of a well-designed user interface, that suddenly becomes less relevant on a smart speaker. When you talk to a computer rather than look at it, you are beholden a single purveyor of a single stream of information. You can’t quickly switch between apps and songs like you can on a screen.
“Spotify has always been looking to diversify from [music] rights,” says a separate, legal source close to the company, who added that the company has 70 to 80 lawyers advising on everything from digital content arrangements to dealing with Silicon Valley tech giants.
Maybe if they want to be taken seriously they should hire a lot more engineers, too.


Over the past few months, as I sat contemplating one of the biggest decisions of my life - whether to announce that my time as head of USGBC was sunsetting, and that in a year- and-a-half I would enter an exciting new chapter of life during which I would start tackling any number of the projects on my still-robust wish list - I remained torn right up to the very end.
But then one morning out of the blue, I received an email and in the process found myself blessed with a wonderful, almost magical and deeply cathartic moment of clarity.
It was in reading this particular email over coffee that the decision I had labored over for so long became -- for the first time ever - well, easy. The email was from a young man named Devin Rosen, whose words - and I mean this literally - brought tears to my eyes.
Even though I had only met Devin once, I never forgot him because the young man blew me away. It was 2007. We were both on Capitol Hill to testify at a Green Schools Caucus; me as an activist getting paid to do what I do, him as a 10 year-old student deeply concerned about his generation's relationship to our planet, and how it may play out in the years ahead.
"You sat right next to me as we testified before Congress at the Green Schools Caucus briefing. I was there representing my school, Great Seneca Creek Elementary. As a fifth grader, I wasn't really aware of the significance of the situation. I just thought I was talking to a bunch of people, like my dad, who wore fancy suits and ties. Now I recognize the experience as one of the huge accomplishments of my life so far."
And the tone in that passage was the exact brand of innocence, honesty and old-soul wisdom Devin put on display that day before Congress some eight years ago. That's why I never forgot him.
"Once the briefing finished, you came up to me, firmly shook my hand, gave me your business card, which I still have, and bestowed upon me a pen in a nice case with the USGBC emblem on the front (I actually used that exact pen on my AP exams this year. It still works well). You told me to give you a call once I graduated. Well, now as an 18-year-old high school graduate with big, bright, solar-powered dreams for the future, I figured I would contact you and say hello."
As I read the above passage, suddenly all the tumblers fell into place. I saw clearly for the very first time that I could, indeed, step aside and let go of the reins of the USGBC. And I could do so with a clear conscience, because not only would the organization we conceived and nurtured so many years ago be in good hands now, it would be in even better hands in the not-too-distant future. I saw that there are generations of environmental leaders still to come who will march forward relentlessly like columns upon columns of soldiers with right and goodness on their side.
Let me cue you in on a little secret. Even though the word sits in our title, all bare, bold and unapologetic, USGBC has never really, truly been about buildings. Not, in fact, by a long shot. It's been about those who inhabit those buildings, and those who design, build and use them.
In other words, It's been all about people. Or, to put even a finer point on it, USGBC has been about the children - yours, mine and theirs - and the future they will write.
It was in reading Devin's email that I was suddenly reminded of that, just as I was reminded of something that perhaps I'd always known but never fully grasped: At some point my generation - men and women of great depth, character, wisdom and insight who have carried the torch of environmental responsibility and preached the gospel of oneness with nature throughout the most important era in our movement's history - will someday have to pass that torch on.
Not because we've lost our passion, or because we've drifted from our mission. But because, just like any discipline, future generations will go to places, imagine things and scale mountains we never even knew existed.
My friends, I cannot tell you how much playing even a small part in what USGBC has accomplished over the years has meant to me. Nor can I begin to explain the love I have in my heart for the many friends I've made over the years or the emotions that welled up inside me as many of them reached out to wish me well.
But please understand - I'm not going away. I simply have other things I want to do, and an incredible woman with whom I want to spend the rest of my days doing them.


What's the link between bladder infections, CAFOs and Missouri farmers?
I want to highlight a couple of stories we recently produced at the Food & Environment Reporting Network (@FERNnews on Twitter), where I serve as editor in chief. I'm pointing them out because I'm particularly proud of these stories and they took some time to come to fruition.
The first, which appeared last week in a joint investigation with ABC News was reported by Maryn McKenna, a brilliant science journalist who focuses on nasty microbes (check out her recent book Superbug: The Fatal Menace of MRSA). This past spring, she told me she had come across a number of studies that genetically linked the microbes in antibiotic-resistant bladder infections with antibiotic-resistant bacteria found in chicken. I immediately sensed there was a good story here, because bladder infections affect, as the story points out, one-in-seven women.
Although the researchers had, in effect, genetically fingerprinted the bacteria, the question arose whether chicken causes the infections. The researchers assert that chicken are a likely and important source of these highly resistant infections, although as Maryn points out, establishing that in a scientific experiment would be unethical because it would risk infecting healthy subjects with antibiotic-resistant bacteria. The chicken council also issued a press release questioning the link and we quoted these scientists in the Atlantic item mentioned above.
The second story, "Whose Side Is the Farm Bureau On?", which ran at The Nation, concerned the big agricultural lobby (and insurance firm) known as the Farm Bureau. The Farm Bureau puts itself forward as the voice of family farmers but reporter Ian Shearn, a Pulitizer Prize winner, focused on a case in Missouri that showed how the bureau actually operates. When giant CAFOs were polluting the waters around small farms, not only did the bureau support the CAFOs, but it pushed for state legislation that would limit civil suits against such operations. Those suits were being filed by small farmers.
Unlike Maryn's health story, Ian's focused on farmers, but the link between both of them were the practices of concentrated animal operations. While these operations produce plentiful and inexpensive food, they have costs that ripple through society -- whether in being the likely source of recurrent bladder infections commonly suffered by women or in the pollution suffered by Missouri farmers. In short, these stories put a cost on cheap food.
Here's the video from the joint investigation between FERN and ABC News.
Even as interest in all things food-related skyrockets, space devoted to serious food issues continues to lose out to the gastroporn of hot restaurants and hotter chefs. So last year, a group of fed-up food writers launched the Food & Environment Reporting Network (FERN), a nonprofit that funds investigative journalism on matters of food, agriculture, and environmental health. Its first piece, on New Mexico’s dairy industry, was published last fall in High Country News; a second story, published on msnbc.com in January, explained how a drug designed to keep pigs lean is hurting US pork exports. CJR’s Brent Cunningham spoke with Sam Fromartz, FERN’s editor in chief.
Just a quick note. On Sunday, I did an interview with the Heritage Radio Network talking about the new non-profit journalism venture I'm involved with, FERN. This might give you a better idea of what we're trying to accomplish and the type of stories we're doing.
At the link above, you can listen to the whole 30-minute interview or digest it in segments. The host, Katy Keiffer, was a pleasure to talk to -- and she mentioned she actually read this blog. OK, so I know someone is out there!
I'm pleased to announce that this week the Food & Environment Reporting Network launched. I've been working on this a non-profit journalism venture quiety for some time (two or more years), and now serve as editor. It grew out of an impromptu discussion with several people into an organization with a staff, board and editorial advisory board. Our launch coincided with the publication of our first story in High Country News, an award-winning Western magazine which collaborated with us on the piece.
We're supported in this work by several foundations who believe in our vision of producing stories on food, agriculture and environmental health at a time when interest in those areas is growing but in-depth coverage is waning. In our model, we work closely with reporters and media partners so that these stories can see the light of day. We also have a code of ethics that governs our work.
Now, you might wonder, why not just start a blog? Well, blogs are good models, but what we have in mind is traditional reporting: sending a reporter into the field on an in-depth investigation and giving them the chance to really look into a story. This kind of work is expensive and often falls through the cracks in the rush of the 24-hour news cycle. If you're tied to a blog, this work is especially tough.
Our first story is a clear example of how this works. Reporter Stephanie Paige Ogburn went down to New Mexico to look into a story about water pollution arising from large dairy farms, focusing on a citizen who launched a campaign to fight it. The story is a good one, in part because the character isn't your typical "environmentalist." (He sports an NRA hat). Ogburn widens the net from what might be viewed as a local story, tying it into broader issues the West has faced with mega-dairies. She also explains the complex regulatory issues with ease.


Shepherds: Annunciation -- Angel, emanating rays, holding scroll inscribed PUER NATUS EST, appears in arc of heaven in sky above two shepherds, including one kneeling, holding bagpipe in both hands, and the other with hat hanging around his neck, holding staff in left hand, and with right hand raised. Between the shepherds sits a dog. In background are flock of sheep, trees, and distant castle.
1) John Baptist: preaching -- John, nimbed, wearing garment of skins, gesturing, stands before three men, one kneeling with hands crossed on his breast. In background are trees and sky with stars.
2) John Baptist: preaching -- John, nimbed, wearing garment of skins, gesturing, stands before four soldiers, all wearing armor, one kneeling with joined hands raised. Diapered background.
3) John Baptist: recognizing Christ -- Christ, with crossed nimbus, stands with right hand raised before John Baptist, nimbed, wearing garment of skins, kneeling with joined hands raised. Sky with stars in background.
4) Christ: Baptism, removing Garments -- Christ, with crossed nimbus, wearing short loin cloth, removes outer garment. Before him kneels John Baptist, nimbed, wearing garment of skins, with hands on his breast. Sky with stars in background.


This one is about: Fetal Cleft Palate Repair: Could it Someday Become a Reality?
Recent observations have shown that fetal skin tissue, if repaired early in gestation, heals without scarring. The authors sought to test this lack of scarring phenomenon in a fetal lamb model. Surgical clefts of the palate were created and repaired in the same operation in ten fetal lambs. The surgery was performed at different gestational ages. After repair the fetuses were returned to the uterus. One month after birth the palatal tissue was examined. The results indicated that when the clefts were repaired before 70 days gestation there was no scar formation and the tissue appeared normal in every respect. In the clefts repaired after 70 days gestation significant scar formation was observed.
This is one of the first studies to specifically focus on fetal cleft palate repair. Earlier studies have focused on fetal repair of clefts of the lip and alveolus. Further studies are needed to determine differences in fetal healing between the lip and palate. Additionally, more studies are needed in large animal models before application to human fetuses can become a possibility.
The big question in everyone's mind, of course is this: What does this mean for our children? Well, it could mean nothing, and it could mean everything. But most of all it means that the future of cleft care is full of exciting possibilities.
Of course, for children already born, fetal repair is a moot point. But for our children's siblings yet to be born, and for our children's children, and for generations to come, there may be some very welcome news indeed on the horizon.
Could it be possible to actually "undo" a cleft, simply by repairing it early enough? At this time, we don't know for sure, but the research is promising. If, however, we find that what we are learning from these early animal studies remains true for human fetuses as well, then there may very well be a time when a child with a cleft can be born perfectly normal.
However, even under the best of circumstances, that time is not exactly just around the corner. As is indicated in the review, many more studies must be done before we can even begin to apply this technology to human babies. And, while some fetal surgery is done today, it is done only rarely, and then only for life threatening conditions, and not for cleft repair. Fetal surgery is simply too risky for both the mother and child.
More realistically, this sort of research teaches us a great deal about how the body forms scar tissue and how scar tissues resulting from surgeries may be minimized in the future - even when surgery is performed after birth.
By some estimates we might see some of this technology actually affecting our children within the next few decades. When one realizes how that, at the beginning of this century a cleft was considered a "crippling" condition, and the cleft-born person was treated as an outcast, one can hardly help but believe the truism that "we've come a long way, baby!"
The possibility of prenatal surgical repair, as well as other technological surgical advancements, is one of the best arguments ever for perfecting the technology that allows for prenatal diagnosis. At present, a prenatal diagnosis allows the family to prepare for the birth of a cleft-affected child. Perhaps in the future such a diagnosis can provide parents with the opportunity of avoiding the problems that go along with a cleft-affected birth.
As promising as that may be, there will probably always be cleft-born children. A prenatal diagnosis occurs most often when possible problems with the fetus are suspected - perhaps because one or the other parent has an inheritable condition. Many clefts remain unsuspected, and therefore, many children will continue to be born with a cleft that is suspected only when it is evident by birth.
But perhaps the cleft-affected child born today can conceive with the certainty that her child need not be born with a cleft as well - even if the gene is shared. Dare we dream?
The Cleft Palate-Craniofacial Journal: Vol. 35, No. 5, pp. 425P429.
Eric J. Stelnicki, M.D., Karen Vanderwall, M.D., William Y. Hoffman, M.D., Zoltan Szabo, Ph.D., Michael R. Harrison, M.D., Rob Foster, and Michael T. Longaker, M.D.
Interventions and Results: In contrast to previous open fetal cleft lip repairs in the same model, none of the five fetuses reported here had a good aesthetic result. Although there was no evidence of scar histologically, the edges of the lip were poorly approximated. The epithelial lining and underlying dermis of the wound margins were notably inverted. The orbicularis oris muscle, which had been reapproximated, appeared thin and hypoplastic. Most of the vermilion elements were poorly aligned, and in one animal, there was a complete dehiscence of the repair.
Conclusions: In a more representative model of cleft lip that is not an acute lip wound, in utero endoscopic suture repair of the ovine lip gave a poor result using current technology. Only a meticulously performed, multilayered, open repair of a cleft appears to give a good cosmetic and functional outcome. Further studies to improve the endoscopic repair as our technology advances are therefore warranted.
--------Dr. Canady, the author of the research discussed above, will be attending the WIDE SMILES Symposium on Cleft care, where he will present topics on the Future of Cleft Care and on Adolescent Issues.