Cruise M127 is an integral part of the EU-FP7 project "Blue Mining: Breakthrough Solutions for
the Sustainable Deep Sea Mining Value Chain" and is addressing research questions regarding
the nature and resource potential of marine minerals, especially seafloor massive sulfides (SMS)
along mid-ocean ridges. The cruise left from Bridgetown (Barbados) in the evening of May 25th
and reached the working area at 26°N on the Mid-Atlantic Ridge on May 30th (Fig.1.1). One of
the main tasks during the cruise was mapping of the TAG segment (26°N) in various resolutions.
This included ship-based multibeam mapping over the entire length of the ridge segment as well
as high-resolution mapping using an autonomous underwater vehicle (AUV) flying close to the
seafloor (40-100 m altitude).
The ship-based multibeam mapped along 710 nautical miles of profile lines covering
approximately 7,000 km2 in the working area. Another 1,800 nautical miles of lines were mapped
on the transit from Barbados to the working area and from there back to the Azores. The AUV
was used on 19 missions, usually with survey times close to the seafloor of between 10 and 12
hours. Most dives provided maps with a resolution of 2 m and collected a number of other
parameters with its sensors at the same time. Two dives were devoted to mapping points of
interest in 50 cm resolution.
Seismic work, as the 2nd important part of the cruise, included refraction and reflection
seismics with airgun shots and multichannel seismic streamer records being compiled along 49
profiles on 8 survey runs (230 nautical miles in total length). Additionally, 22 ocean bottom
seismometers (OBS) and 9 ocean bottom hydrophones (OBH) deployments were undertaken. The
seismic work was hampered by problems with the compressor, for which the oil could not be cold
enough at the beginning. This was later solved with the help of the ships crew. Deep-towed
streamer work could also not be performed because of continued problems with the streamer that
could not be resolved on board. A series of 6 ocean bottom electro-magnetic stations (OBEM)
were deployed as preparation for the up-coming RRS James Cook cruise, which is also part of the
Blue Mining project.
A modular towed instrument platform (HYBIS) was used to deploy 10 of the (OBS) to the
seafloor with high precision. Since this platform has built-in cameras and can be equipped with a
sampling module we used this instrument later in the cruise to further visually inspect the
seafloor and select locations for sampling.
The final instrument being used was a short (3m) gravity corer for sediment sampling. In the
course of the cruise 35 stations were attempted of which 22 stations successfully retrieved
sediment for some of which ship-board analyses showed very high concentrations of copper.
Rock fragments were recovered in 9 stations indicating the volcanic nature of those sampling
stations. At the end of the cruise all Ocean Bottom Seismometers (OBS) were recovered. Only
the six OBEM were intentionally left behind.
Station work in the working area ended on 20:30 LT on June 23rd when the 5 day transit to
Ponta Delgada was started. During the transits from and to the working area 3 ARGO floats were
deployed and the ship-based multibeam and the 75-kHz ADCP collected data in international
waters. The cruise ended 09:00 LT of June 28th with docking in Ponta Delgada.
Overall on 1/3 of the cruise was used for the transit and 2/3 for stations work and transits
within the working area (Fig. 1.2). Most of station time was devoted to geophysical work
including seismic profiling and the deployment and recovery of the instruments.


Background: The use of psychological therapies for patients with psoriasis has been proposed based on observations that the severity of their disease may correlate with emotional stress. The aim of this pilot study was to evaluate the effect of hypnosis as a treatment modality for patients with psoriasis. Methods: We performed a 3-month randomized, single-blind, controlled trial of the use of hypnosis in adults with stable, chronic, plaque-type psoriasis. Highly or moderately hypnotizable subjects were randomized to receive either hypnosis with active suggestions of improvement (5 patients) or neutral hypnosis with no mention of their disease process (6 patients). After this period, the study was unblinded, and all the patients were treated for an additional 3 months with hypnosis with active suggestions of improvement. Results: Highly hypnotizable subjects showed significantly greater improvement than did moderately hypnotizable subjects, independent of treatment group assignment (active suggestion or neutral hypnosis). Conclusion: Although this study included a very limited number of patients, the results suggest that hypnosis may be a useful therapeutic modality for highly hypnotizable subjects with psoriasis, and merits further testing in a larger patient population.


Survival strategies exhibited over 4 years by Ralstonia solanacearum phylotype (ph) II biovar (bv) 2 in environmental water microcosms were examined. The bacterium is a devastating phytopathogen whose ph II bv 2 causes bacterial wilt in solanaceous crops and ornamental plants. Outbreaks of the disease may originate from dissemination of the pathogen in watercourses, where it has to cope with prolonged nutrient limitation. To ascertain the effect of long-term starvation on survival and pathogenicity of R. solanacearum in natural water microcosms, survival experiments were conducted. Microcosms were prepared from different sterile river water samples, inoculated separately with two European strains of ph II at 10(6) c.f.u. ml(-1) and maintained at 24 degrees C for 4 years. In all assayed waters, starved R. solanacearum remained in a non-growing but culturable state during the first year, maintaining approximately the initial numbers. Thereafter, part of the population of R. solanacearum progressively lost the ability to form colonies, and non-culturable but metabolically active cells appeared. During the whole period, the bacterium remained pathogenic on host plants and underwent a transition from typical bacilli to small cocci which tended to aggregate. Some starved R. solanacearum cells filamented and formed buds. Starvation response, viable but non-culturable state, morphological changes and aggregation have not previously been reported for this pathogen as survival mechanisms induced in oligotrophic conditions. The potential existence of long-starved pathogenic cells in environmental waters may raise new concerns about the epidemiology of bacterial wilt disease.


Context: Aiming at gaining knowledge about students' thoughts and actions in deciding to stay in or drop out of an educational programme, an empirical study was conducted on dropout among 18-24-year-old students in VET and basic general adult learning. Approach: In order to pursue this aim, the study combined two sets of data: weekly student surveys and interviews with these same students. While the surveys provide a weekly snapshot of the students' thoughts regarding the probability of them continuing in the programme, their satisfaction with the educational programme as a whole, the specific lessons they attend, and the atmosphere at the school, the interviews contribute with detailed descriptions of the students' thoughts on the same matters.Findings: Based on the students' answers over an eight-week period, it was possible to trace a graph illustrating changes in the students' attitudes. These graphs can be placed within four categories of development: the stable, the positive, the unstable, and the negative. The latter can furthermore be differentiated as reflecting a stable decline, a fluctuating decline, or a sudden decline. In the interviews, the aim was to elicit the individual students' thoughts and actions at the points when their graphs took a turn. Conclusions: The findings show that the students' thoughts and actions concern matters both inside and outside the school. Furthermore, seemingly trivial matters in the students' lives are shown to have a potentially decisive influence on the students' thoughts about staying in or dropping out of a programme. These findings confirm the importance of focusing on students' decision-making processes in research on dropout. However, further research is needed to increase understanding of processes leading to decisions to drop out of education, including the qualification of methods to capture these processes.


In this thesis report, an approach to use Microsoft Kinect to scan an object and providea 3D model for further processing has been proposed. The additional requiredhardware to rotate the object and fully expose it to the sensor, the drivers and SDKsused and the implemented software are discussed. It is explained how the acquireddata is stored and an efficient storage and mapping method requiring no specialhardware and memory is introduced. The solution proposed circumvents the PointCloud registration task based on the fact that the transformation from one frame tothe next is known with extremely high precision. Next, a method to merge theacquired 3D data from all over the object into a single noise-free model is proposedusing Spherical Transformation and a few experiments and their results aredemonstrated and discussed.


Building Information Age Businesses for the 21st Century, Lynda M. Applegate Appendix A: E-Business Models Appendix B: E-Business Revenue and Cost Models The Embedding Stage of Electronic Commerce, Vladimir Zwass Web Evaluation, Carsten Totz, Kai Riemer, and Stefan Klein Supply Chain Management, G. Prem Premkumar Online Auctions: A Closer Look, Alok Gupta and Ravi Bapna Bid Together, Buy Together: On the Efficacy of Group-Buying Business Models in Internet-Based Selling, Robert Kauffman and Bin Wang The Great Experiment: Pricing on the Internet, Karen Clay, Ramayya Krishnan, and Michael Smith Virtual Trade Fairs: An Emerging Internet Application, Ramesh Sharda and Ramesh Sambasivan Planning Business-to-Business E-Procurement Marketplaces, Jae Kyu Lee and Efraim Turban Internet Evolution and Social Impact, Sara Kiesler, Robert Kraut, Jonathon Cummings, Bonka Boneva, Vicki Helgeson, and Anne Crawford Designing a Curriculum for the Death of E-Business: Five Principles, Bradley C. Wheeler Electronic Commerce Partnerships Between Business and Academia, J. Owen Cherrington and Brian Carini The Covered Bazaar on the Internet: Culturally Specific Alternatives to "Web-Marts", Fay Sudweeks and Simeon J. Simoff Electronic Government, Yurong Yao and Blake Ives E-Business Goes Global: Institutional Environments and Governance of Global Internet Firms, Sirkka L. Jarvenpaa and Sai K. Yayavaram Paradigm for Financial Modernization in E-Commerce, Martin Nemzow Knowledge Management in E-Services: From Mass Customization to Service Individualization, Amrit Tiwana and Balasubramaniam Ramesh Preventing and Detecting Fraud in Electronic Commerce Systems, W. Steve Albrecht and Conan C. Albrecht Protecting a Borderless World: Recognizing and Understanding Security Threats to E-Commerce, Steven Roberts and Dorothy E. Denning The Critical Role of Independent Security Audits, Nahum Goldmann and Edward Orton Trusted Electronic Market Transactions: A Macro- and a Micro-Level View, Gunther Pernul, Alexander W. Rohm, and Gaby Herrmann Development of Reliable E-Commerce Applications in Large and Open Distributed Systems, Rida A. Bazzi and Feras Karablieh Distributed Software Component Integration: A Framework for a Rule-Based Approach, Susan D. Urban, Suzanne W. Dietrich, Amy Sundermier, Ying Jin, Sunitha Kambhampati, and Yinghui Na Collaborative Architectures that Support Electronic Business, Conan C. Albrech A Business Component-Based Approach to E-Business Process Design, Amitava Dutta and Tarun K. Sen Reducing Distance in Electronic Commerce using Virtual Reality, Kenneth R. Walsh XML, A Collaborative Enabler of E-Business through the Mediation of Heterogeneous Data between Trading Partners, Paul Benjamin Lowry and William T. Neumann


Problems for environmental management are taking on a new urgency. This book addresses aspects of environmental management that raise fundamental questions about governmental roles and the relationship of humans to the environment. It examines the interaction of local and national governments and the strengths and weaknesses of co-operative vs. coercive environmental management, through a focus on the management of natural hazards. Leading experts in the field examine new and innovative environmental management and planning programmes with particular focus on North America and Australia. This book offers a new understanding of environmental problems and explores the appropriate policy mix that must be developed for environmental management to strive towards environmental sustainability.


About the book:
the definitive reference source for the exploration of Japanese business and management. Reflecting the multidisciplinary nature of this field, the Encyclopedia consolidates and contextualises the leading research and knowledge about the Japanese business system and Japanese management thought and practice. It will be welcomed by scholar and student alike as an essential resource for teaching, an invaluable companion to independent study, and a solid starting point for wider exploration.


'Order' is a funny, fuzzy term in the international relations literature. While scholars have adopted many different definitions for the concept, most have not been clear on how their conception can be measured, how it can logically and empirically vary, and how it complements or clashes with alternative conceptualizations of the same term. In short, the literature on order in international relations is in a state of utter disorder. This paper aims to clean up the messy conceptual debate over what 'order' means in world politics. Drawing from both international relations (IR) theory and the literature on concept formation in the social sciences, it presents a new conceptualization of international order that seeks to address the shortcomings of its predecessors. More specifically, I present a 'two-step' conceptualization of international order that helps us both clarify and move beyond the stale debate between realism, liberalism and constructivism in IR theory. The first step establishes a baseline definition of what kind of behavior constitutes a state of order in the international system. The second step focuses on the 'stuff' that must be present to induce the behavior identified in the first step. I posit that while the three major approaches to order in the IR theory literature ultimately agree on the first step definition, they disagree on this crucial second step. The paper proceeds in four sections: First, I offer a first-step definition for order as patterned, equilibrium-perpetuating behavior among a particular system's units. That is, an ordered system induces its units to behave in ways that enable and reproduce the status quo. I then show how this definition broadly fits with how realists, institutionalists and constructivists already approach international order. Second, I demonstrate that the differences between these approaches come not in the first step definition but in the second. While realists emphasize material power forces bringing about this equilibrium-perpetuating state, liberals focus on the institutional environment and constructivists upon the presence of common ideas or identities across actors. Third, I develop my own second-step conceptualization, arguing that the 'stuff' of order can most usefully be conceptualized as the presence of 'observed rules' among an international system's units. Finally, I explicate the ways in which, in this new conceptualization, order could logically and empirically vary. I conclude by combining these elements to begin sketching a logically exhaustive typology of international orders.


Indeterminate Bodies organizes a number of theoretical and empirical studies around the concept and actuality of indeterminacy, as it relates to body and society. Located within the struggle to apprehend different categories of 'body' in the volatile flows of late-capital, indeterminacy is considered through such multiple incarnations as economy, contingency, inheritance, question, force, uncertainty, materiality and affective resistance to determination. While indeterminacy is often positioned as the 'trouble' or friction in subject/object knowledge-formation (framed as ontological or empirical challenge), it also engenders affects such that some subjects are both in and out of recognition. Questions of indeterminacy overlap with work on imperceptibility, giving rise to interlocked questions about the modes of representation, categorization, inclusion, exclusion and sensibility in the production of bodies. We address the hesitancies, difficulties and necessities of working with and through indeterminacy in order open up new descriptions, visions and modes of political work.


Environmental reservoirs are the potential sources of pathogenic E. coli. These are ideal habitat for survival, growth, and proliferation of E. coli as they are rich in nutrients. A wide range of different animals harbor pathogenic E. coli, which are consistently associated with human and animal diarrheal infection. Infected cattle typically excrete pathogenic E. coli. These discharges are released into the aquatic environment or storm water runoff. The surface water carries a number of pathogenic bacteria when used for the drinking purposes. Apart from these, the water is treated in municipal treatment plants and supplied through pipelines for drinking purposes. The processed clean water sometimes also gets contaminated due to leakage of nearby sewer lines. Highly prevalent diarrheagenic E. coli variants are present in the surface and potable waters in India. The consumption of unsafe water in developing countries causes a number of disease outbreaks. The detection of target pathogens needs improvements to overcome existing drawbacks and should be based on simple, sensitive and specific methodologies. Polymerase Chain Reaction is one of the latest techniques in modern biology which is effective in the detection of these pathogens. Real Time PCR technique has advantages over conventional methods in terms of rapidity, high specificity and sensitivity. The real time PCR uses primer pair and molecular probe (TaqMan, Molecular Beacon, Scorpion etc.) for the sensitive detection of pathogens.


In recent years, increasing concerns about climate change and the liberalisation of the energy market have provided the necessary impetus for a revolutionary restructuring of the electricity network. Traditional power networks are designed to operate in a passive and unidirectional way as their main functionality encompasses the transfer of energy from the power stations to the customer, with minimum loss. Increased electricity production from renewable energy sources (RES) coupled with energy efficiency lie at the heart of the ambitious targets set by Europe and globally in the quest to curb greenhouse gas emissions and to reach energy sustainability. As a result, complete restructuring of the electricity networks will have to take place in order to accommodate increased penetration of RES and distributed generation (DG) which is associated with electricity production from RES. Especially in regions with high solar irradiance, the penetration of photovoltaic (PV) systems is expected to increase in the near future as the technology becomes more competitive. High penetration of PV systems will definitely have serious consequences on the operation of the electricity grid and further challenges will arise as penetration levels increase. Thereafter the security and stability of the power system should be considered carefully to identify possible impacts due to uncontrolled deployment. The occurrence of power quality problems is not only negatively affecting utility customers but is also affecting the generated energy from Photovoltaic (PV) systems and the stability of the power system. The severity and frequency of occurrence of power quality issues can be the result of distribution grid topology/dynamics, arising due to high PV system concentration or even abnormal PV system operation. Analytical tools and accurate models of PV systems must be developed in order to evaluate their behaviour in the context of the full network. The utilization of accurate simulation models is of great importance in an attempt to assess the real consequences of localized energy production from distributed energy sources and in particular PV. A common detailed PV system model is formed by a PV array, an inverter and a power grid interface as shown in Fig. 1. Figure 1: General schematic of a Detailed Photovoltaic System. The PV array is affected by the solar irradiance, the temperature and the specific characteristics of the chosen PV module technology. The PV array converts the solar irradiance into DC power which is then delivered to the distribution grid via the PV inverter. A Maximum Power Point Tracking (MPPT) Controller is used to absorb the maximum available energy. The MPPT Controller varies the duty cycle of a DC/DC converter to adjust the voltage at the output of the PV array (DC link A). The DC/DC converter is connected to a DC link (DC link B) of which the voltage is maintained constant by a DC/AC inverter circuit topology. In more detail, the DC/AC inverter is set to inject the power reaching the DC link B into the electricity grid and in that way the DC link B remains constant. A filter is always placed at the output of the inverter to eliminate undesirable harmonic currents produced by the switching operation of the inverter [1]. A generic PV system model for transient studies, the parameters of which can be tuned using transient data is developed in this work. The adopted analysis utilizes existing knowledge to formulate an accurate transient representation that considers the PV system control circuit and dynamics [2], [3]. The model is tuned and validated using transient data obtained from a detailed PV system circuit topology developed in Matlab Simulink via the Nelder-Mead simplex algorithm [4]. Its abstract representation is shown in Fig. 2. The proposed model is actually a three phase representation capable of simulating with sufficient accuracy normal/unbalanced operating conditions and voltage regulation. Harmonics are also incorporated into the model to reveal its capability for use in complete power quality studies. Figure 2: Proposed Transient Photovoltaic System Model (TPVSM). This PV system model is able to characterize the transient behaviour of PV systems in a generic way via a parameter estimation process. In addition, it enables the analysis of more aspects of power quality and voltage stability with higher accuracy under balanced and unbalanced conditions. It must also be pointed out that the proposed model is simpler and faster, thus allowing the computationally efficient simulation of complex problems. Figure 3: Output current response to a step change in active power input. The transient response of both the detailed and the proposed PV system model during a step change in active power input is shown in Fig. 3 (the reactive power input is kept at a zero value). In the next step, the developed model is used to assess the voltage transient response of a distribution grid busbar (point of common coupling of the PV system with the electricity grid) and the results are shown in Fig. 4. The comparison is made with the "Theil inequality coefficient". The specific inequality coefficient provides a measure of how well a time series of observed values compares to a corresponding time series of estimated values. A value of 0 indicates zero difference or perfect predictions, whereas a value of 1 indicates poor model performance. Values lower than 0.3 depict good agreement between estimated and observed data. As can be seen from the results and inequality coefficient in Figs. 3 and 4, good agreement has been obtained between the detailed and the proposed PV system model. It is important to stress that the proposed generic model can been tuned by using experimental data as well. Figure 4: Transient reponse of voltage during a step change in reactive power reference. In summary, the proposed generic model is in line with current DG standards as it can be used for studies of voltage regulation/power quality. The aim of the aforementioned research is to enhance the effort of assessing the consequences of high PV penetration and facilitate corrective action with appropriate technical solutions so as to enable the safe and unrestricted deployment of these technologies in electricity grids [5]. References [1] S.-K. Kim, J.-H. Jeon, C.-H. Cho, E.-S. Kim, and J.-B. Ahn, "Modeling and simulation of a grid-connected PV generation system for electromagnetic transient analysis," Sol. Energy, vol. 83, no. 5, pp. 664–678, May 2009. [2] M. Liang and T. Q. Zheng, "Synchronous PI control for three-phase grid-connected photovoltaic inverter," in 2010 Chinese Control and Decision Conference, CCDC 2010, 2010, no. 2, pp. 2302–2307. [3] Z. Xueguang, X. Dianguo, and L. Weiwei, "A novel PLL design method applied to grid fault condition," in Conference Proceedings-IEEE Applied Power Electronics Conference and Exposition-APEC, 2008, pp. 2016–2020. [4] W. Bao, X. Zhang, and L. Zhao, "Parameter estimation method based on parameter function surface," Sci. China Technol. Sci., vol. 56, no. 6, pp. 1485–1498, 2013. [5] M. Patsalides, A. Stavrou, V. Efthymiou, and G. E. Georghiou, "A Generic Transient PV System Model for use in Power Quality Studies," Renew. Energy, 2015, Accepted.


Macroalgae are undoubtedly a major supplier of organic carbon to marine food webs, yet few studies have attempted to examine primary production in complex macroalgal communities. Many studies have tested the photosynthetic characteristics of single species with little attention given to the associated algal assemblages. The role of canopy structure and species diversity in these assemblages will help in understanding the role of biodiversity in enhancing ecosystem function. In the present study, photosynthesis-irradiance relationships (P-E curves) of intact intertidal algal assemblages showed no signs of saturation at high irradiance levels, as is typically seen in single- species curves. Canopy-forming species appear to play a vital role in enhancing overall assemblage net photosynthesis, particularly at high irradiances (>1500 µmol m -2 s -1 ), with the loss of canopy species causing up to a 50% decline in the photosynthetic rate of assemblages. There is also evidence that the mechanisms of light use are significantly different in intact assemblages because they do not act as the sum of their parts at high irradiance levels. Furthermore, with greater structural com- plexity, net photosynthesis of the assemblage is enhanced, particularly at high irradiance. The present study demonstrates the importance of using realistic species compositions and assemblage structure to identify the potential mechanisms enhancing function with increasing diversity. A better understanding of light-use efficiency within macroalgal communities underpins the role of biodiver- sity and community structure in these ecosystems and the potential effects of species loss on various forms of ecosystem function.


Motivated by recent phonon spectroscopy experiments in the fractional quantum Hall regime we consider processes in which thermally excited magnetoroton excitations are scattered by low energy phonons. We show that such scattering processes can never give rise to dissociation of magnetorotons into unbound charged quasiparticles as had been proposed previously. In addition we show that scattering of magnetorotons to longer wavelengths by phonon absorption is possible because of the shape of the magnetoroton dispersion curve and it is shown that there is a characteristic cross-over temperature above which the rate of energy transfer to the electron gas changes from an exponential (activated) to a power law dependence on the effective phonon temperature.


Among all non-linear optical effects observed in single-mode optical fibres, stimulated Brillouin scattering (SBS) is of particular importance since it has numerous practical implications. SBS occurs when laser waves are scattered through the interaction of light with hypersonic acoustic waves in the medium. It manifests through the generation of a backscattered Stokes wave that carries most of the input optical power once a definite intensity level is reached within the fibre core. It limits the maximum optical power that can be transmitted through an optical fibre and therefore can cause a severe penality for fibre optics telecommunications. The backscattered Stokes wave is down shifted in frequency with respect to the incident lightwave frequency. This frequency shift – often called the Brillouin frequency shift – depends on the fibre parameters and on the wavelength of the incident light. It is directly proportional to the acoustic velocity and ranges from 12 to 13 GHz for silica fibres at a 1.3 µm wavelength. The Brillouin frequency shift is also very sensitive to environmental quantities changing the acoustic velocity such as temperature and strain. This feature makes SBS very interesting for temperature and strain monitoring in optical fibres and has been used in the design of fibre optics sensors. In the present work, a novel method to measure SBS characteristics in single-mode optical fibres has been developed. It is based on the so-called pump and probe technique using two counterpropagating optical waves within the test fibre. It basically presents the originality to require only one laser source and relies on an electro-optic modulator to generate the probe signal by microwave modulation of the pump light. The inherent high stability of the experimental set-up has made possible the characterisation of different fibres in terms of SBS parameters with a higher accuracy than the traditional two lasers set-up. The influence of dopant concentration in silica fibres on the SBS properties has been fully characterised. Furthermore it has been determined that the presence of core dopants decreases the acoustic velocity resulting in a smaller Brillouin frequency shift. The temperature and strain effects on the SBS characteristics have been extensively investigated. The problem of the evolution of the polarisation of the interacting lightwaves has been studied and a model clarified the so far unexplained behaviour in low birefringence fibres. A new measurement procedure has been defined to achieve polarisation-independent Brillouin gain determination. The second facet of the present thesis deals with the concept of distributed fibre optics sensors based on SBS. The determination of the Brillouin frequency shift gives access to the temperature or strain experienced by the fibre, while a modified OTDR technique provides the information on the position. Here again the use of a single laser source together with an electro-optic modulator brings several advantages. Besides the convenient flexibility in the generation of the probe signal, it makes possible to pulse the optical signals to localise the interaction within the test fibre. The overall temperature or strain distribution of the test fibre can be carried out by measuring the Brillouin frequency shift at any locations throughout the test fibre. A sensor has been experimentally achieved and its performances can be summarised as follow: spatial resolution less than 10 meters over more than 10 kilometres, with a resolution on the Brillouin frequency determination of 1 MHz, that corresponds to a ±1°C temperature resolution or to a 2x10-5 strain resolution. The dynamic range can be increased up to 30 kilometres to the detriment of the spatial resolution. The ultimate performances of the SBS distributed fibre optics sensors have been investigated in terms of spatial resolution and dynamic range. It turns out that these sensors are eventually dedicated to distributed measurements over several tens of kilometres with a spatial resolution limited to the meter range. Finally two practical applications of such sensors are described: the measurement of the strain distribution in installed fibre optics cables for telecommunications and the temperature monitoring of electrical energy distribution cables. On site measurements using a Brillouin sensor have been performed for the first time thanks to the high stability and reliability of the sensor.


The economics of biodiesel production shows that the cost of raw material is the main driver of the overall production costs. Operation cost of biodiesel production does not reflect significant economy of scale because scale-dependent variable such as labour, chemical and maintenance costs are only a small part of the operating expenses. The success of the biodiesel industry is therefore reliant upon the availability of adequate supplies of reasonably priced feedstocks. The potential oil crops for use in Southern Africa countries for biodiesel production are not well-documented. This paper analyzes the potential availability of biodiesel feedstock in Southern Africa and discusses their suitability, adaptability of the various oils as precursors for biodiesel production. Potential feedstocks are identified which is by no means an all inclusive list but contains major oil crops/feedstock that can be used for biodiesel production. The current and future availability of each feedstock are evaluated and growing regions for dedicated biodiesel oil seeds is proposed using multi criteria decision analysis based on analytic hierarchy process methodology. This paper also discusses the sustainability of using non-food crops as biodiesel feedstock against the backdrop of current biofuel policies and initiatives in Southern Africa. This study provides investment information to potential investors and further set the context for biofuel discussion and development in the African continent.


Isolated complex I deficiency is the most frequently observed oxidative phosphorylation defect in children with mitochondrial disease, leading to a diverse range of clinical presentations, including Leigh syndrome. For most patients the genetic cause of the biochemical defect remains unknown due to incomplete understanding of the complex I assembly process. Nonetheless, a plethora of pathogenic mutations have been described to date in the seven mitochondrial-encoded subunits of complex I as well as in 12 of the nuclear-encoded subunits and in six assembly factors. Whilst several mitochondrial DNA mutations are recurrent, the majority of these mutations are reported in single families. We have sequenced core structural and functional nuclear-encoded subunits of complex I in a cohort of 34 paediatric patients with isolated complex I deficiency, identifying pathogenic mutations in 6 patients. These included a novel homozygous NDUFS1 mutation in an Asian child with Leigh syndrome, a previously identified NDUFS8 mutation (c.236C>T, p.P79L) in a second Asian child with Leigh-like syndrome and six novel, compound heterozygous NDUFS2 mutations in four white Caucasian patients with Leigh or Leigh-like syndrome. Three of these children harboured an identical NDUFS2 mutation (c.875T>C, p.M292T), which was also identified in conjunction with a novel NDUFS2 splice site mutation (c.866+4A>G) in a fourth Caucasian child who presented to a different diagnostic centre, with microsatellite and single nucleotide polymorphism analyses indicating that this was due to an ancient common founder event. Our results confirm that NDUFS2 is a mutational hotspot in Caucasian children with isolated complex I deficiency and recommend the routine diagnostic investigation of this gene in patients with Leigh or Leigh-like phenotypes.


Abstract Disabled children are significantly more likely to grow up in poverty than their non-disabled peers. We used longitudinal data from Waves 3–7 (2001–2005) of the UK Families and Children Study to explore the relationship between the presence of a disabled child in the family and poverty transitions. When compared to other families, families supporting a disabled child are more likely to be exposed to persistent or recurrent poverty, less likely to escape from an episode of poverty and more likely to descend into poverty. However, statistically controlling for the effects of salient family characteristics either attenuates, eliminates or reverses these associations. That is, when compared to other families with similar levels of personal and social resources, families supporting a disabled child are no more likely to escape from or descend into poverty than other families. Results are discussed in relation to the need for social policy to invest in strengthening the broader capabilities of families of disabled children.


Get Involved For a Better UNC and A Better You Grow your leadership skills, your intellect and your circle of friends ? get involved to help foster health and well-being at UNC. Student Wellness offers tons of great options. Attend a Student Wellness or health-related event [1]on campus Connect with us to provide education and outreach [2] to your student group Join a Peer Health Organization [3] Register for a workshop or training [4] Visit us [5] for resources, a piece of fruit, or cup of coffee. On us!


Feed industry is very demanding in terms of logistics. This activity implies supplying, processing and, most of all, distributing perishable products (raw materials and feed), to a very large number of clients, often scattered in wide market areas (animal farms) with different qualitative, quantitative and timing needs. So far the use of ICTs within the feed industry in Italy regarded mostly the production phase in terms of feed composition optimisation, and the internal logistics. External relationships like e-CRM, etc.. have so far been rarely adopted. For many Italian small and medium enterprises, mostly in the agro-food sector, the diffusion of ICTs solutions for the management of their client relationship has been quite slow. The aim of this paper is to examine the factors affecting the success in the implementation of an e-CRM solution in an Italian feed industry; the implementation strategies adopted and their impact on the company logistics performances have been investigated; the methodological framework for the e-solution implementation strategy analysis is the "Building of organizational support for Supply chain Improvement" as defined in the SCOR model (Bolstorff P., Rosenbaum R., 2003). The SCOR model provided a useful analytical framework in order to define the variables affecting the successful implementation of the e-CRM. The results show a dramatic improvement in the Progeo- Mangimi customer relationship performances; the fundamental role of the Progeo management to organise and motivate the personnel involved, and to interact with the customers, emerged.


This paper describes a case study of an innovative application of Short Messaging Service (SMS) technology in the higher education sector to enable students to access administrative and assessment information. Moreover, staff can send class group reminders and assessment feedback in the form of tabulated results. The rationale behind the SMS pilot testing of this innovative application implemented recently at an Australian university was to reduce the need for students to access university or home computer systems for course timetables, class locations, assessment schedules, marks and feedback. A powerful additional feature of this technology is to provide students with a familiar communication tool that keeps them informed. To gain the best learning outcome from a class, students can check for reading or work/learning expectations, at any time before the scheduled class. It was concluded that this type of mobile technology pilot usage can in general be extended to guide universities' choice of information service functions with carefully crafted trigger words to increase students' adoption of SMS to enhance their learning satisfaction.


Preface Supplements To the Student: How to Succeed in Your Statistics Course Applications Index 1. Speaking of Statistics 1.1 What Is/Are Statistics? 1.2 Sampling 1.3 Types of Statistical Studies 1.4 Should You Believe a Statistical Study? Focus on Psychology: Are You Driving "Drunk" on Your Cell Phone? Focus on Public Health: Is Your Lifestyle Healthy? 2. Measurement in Statistics 2.1 Data Types and Levels of Measurement 2.2 Dealing with Errors 2.3 Uses of Percentages in Statistics 2.4 Index Numbers Using Technology: Inflation Calculator Focus on Politics: Who Benefited Most from Lower Tax Rates? Focus on Economics: Can a Redefined CPI Help Solve the Budget Crisis? 3. Visual Displays of Data 3.1 Frequency Tables Using Technology: Frequency Tables 3.2 Picturing Distributions of Data Using Technology: Bar Graphs Using Technology: Pie Charts Using Technology: Line Charts and Histograms 3.3 Graphics in the Media Using Technology: Graphs with Multiple Data Sets 3.4 A Few Cautions About Graphics Focus on History: Can War Be Described with a Graph? Focus on Environment: Are We Changing Earth's Atmosphere? 4. Describing Data 4.1 What Is Average? Using Technology: Mean, Median, and Mode 4.2 Shapes of Distributions 4.3 Measures of Variation Using Technology: Boxplots Using Technology: Standard Deviation 4.4 Statistical Paradoxes Focus on the Stock Market: What's Average About the Dow? Focus on Economics: Are the Rich Getting Richer? 5. A Normal World 5.1 What Is Normal? 5.2 Properties of the Normal Distribution Using Technology: Standard Scores in Excel Using Technology: Standard Scores and Percentiles 5.3 The Central Limit Theorem Focus on Education: What Can We Learn from SAT Trends? Focus on Psychology: Are We Smarter than Our Parents? 6. Probability in Statistics 6.1 The Role of Probability in Statistics: Statistical Significance 6.2 Basics of Probability 6.3 The Law of Large Numbers 6.4 Ideas of Risk and Life Expectancy 6.5 Combining Probabilities (Supplementary Section) Focus on Social Science: Do Lotteries Harm the Poor? Focus on Law: Is DNA Fingerprinting Reliable? 7. Correlation and Causality 7.1 Seeking Correlation Using Technology: Scatterplots and Correlation Coefficients 7.2 Interpreting Correlations 7.3 Best-Fit Lines and Prediction 7.4 The Search for Causality Focus on Education: What Helps Children Learn to Read? Focus on Environment: What Is Causing Global Warming? 8. From Samples to Populations 8.1 Sampling Distributions 8.2 Estimating Population Means Using Technology: Confidence Interval Estimate of a Population Mean 8.3 Estimating Population Proportions Using Technology: Confidence Interval Estimate of a Population Proportion Focus on History: Where Did Statistics Begin? Focus on Literature: How Many Words Did Shakespeare Know? 9. Hypothesis Testing 9.1 Fundamentals of Hypothesis Testing 9.2 Hypothesis Tests for Population Means Using Technology: Hypothesis Test for a Population Mean 9.3 Hypothesis Tests for Population Proportions Using Technology: Hypothesis Test for a Population Proportion Focus on Health and Education: Will Your Education Help You Live Longer? Focus on Agriculture: Are Genetically Modified Foods Safe? 10. t Tests, Two-Way Tables, and ANOVA 10.1 t Distribution for Inferences about a Mean Using Technology: The t Distribution 10.2 Hypothesis Testing with Two-Way Tables Using Technology: Hypothesis Testing with Two-Way Tables 10.3 Analysis of Variance (One-Way Anova) Using Technology: Analysis of Variance Focus on Criminology: Can You Tell a Fraud When You See One? Focus on Education: What Can a Fourth-Grader Do with Statistics? Epilogue: A Perspective on Statistics Appendix A: z-Score Tables Appendix B: Table of Random Numbers Suggested Readings Credits Glossary Answers Index


A growing number of people--immigrants, refugees, asylum-seekers, displaced individuals, and families--lead lives that transcend national boundaries. Often because of economic pressures, these individuals continually move through places, countries, and cultures, becoming exposed to unique risk and protective factors. Though migration itself has existed for centuries, the availability of fast and cheap transportation as well as today's sophisticated technologies and electronic communications have allowed transmigrants to develop transnational identities and relationships, as well as engage in transnational activities. Yet despite this new reality, social work has yet to establish the parameters of a transnational social work practice. In one of the first volumes to address social work practice with this emergent and often marginalized population, practitioners and scholars specializing in transnational issues develop a framework for transnational social work practice. They begin with the historical and environmental context of transnational practice and explore the psychosocial, economic, environmental, and political factors that affect at-risk and vulnerable transnational groups. They then detail practical strategies, supplemented with case examples, for working with transnational populations utilizing this population's existing strengths. They conclude with recommendations for incorporating transnational social work into the curriculum.


The absorber section is a critical component in solar thermal collectors and is responsible for converting electromagnetic radiation into sensible thermal energy. The optical properties of the surface of the absorber dictates the effectiveness of this conversion. In this work, a manufacturing process is designed to provide bulk surface treatment for solar absorber plates in order to enhance their radiative properties. The process utilizes a novel approach of graphene synthesis and simultaneous deposition via high pressure blasting of graphite. The results show enhanced spectral, thermal and electrochemical performance of the absorber due to the turbostratic nature of graphene adhesion to its surface, especially when three blasting passes are used. The absorptivity of the absorber exhibited a 7% increase when three passes were applied on its surface, while thermal performance increased by 22%. Using graphene has also enhanced the corrosion resistance of the absorber plate. This manufacturing system will provide a facile yet effective treatment of absorbers with various degrees of automation. Applied as a final layer, the process can be retrofitted to existing manufacturing facilities with minimum overhead costs


Only some state of the art driving automation systems (DAS) of current self-driving cars include system restrictions that actively counteract misuse instead of only informing the drivers of the limitations of the system. Misuse can lead to accidents, which could reduce acceptance of self-driving cars at a population level. However, system restrictions could also affect acceptance as DAS with restrictions might be perceived less useful and provide less ease of use. In this paper, we describe an experiment that investigates this trade-off between safety and traditional technology acceptance constructs. We implement four different versions of a driving simulation application using a novel platform for mobile online experiments, MOE. We measure technology acceptance using an adapted UTAUT2 questionnaire before and after the driving simulation and compare it between the four different versions. This research has implications for new technologies that require a trade-off between safety and technology acceptance including self-driving cars.


In 1993 Landauer and Redmond [2] defined a "lattice of information," where a partition over the type of secret's possible values could express the security resilience of a sequential, deterministic program: values within the same cell of the partition are those that the programs does not allow an attacker to distinguish. That simple, compelling model provided not only a refinement order for deterministic security (inverse refinement of set-partitions) but, since it is a lattice, allowed the construction of the "least-secure deterministic program more secure than these other deterministic programs", and its obvious dual. But Landauer treated neither demonic nor probabilistic choice. Later work of our own, and independently of others, suggested a probabilistic generalisation of Landauer's lattice [1, 3] — although it turned out that the generalisation is only a partial order, not a lattice [5]. This talk looks between the two structures above: I will combine earlier qualitatitve ideas [6] with very recent quantitative results [4] in order to explore – What an appropriate purely demonic lattice of information might be, the "meat in the sandwich" that lies between Landauer's deterministic, qualitative lattice and our probabilistic partial order. – The importance of compositionality in determining its structure. – That it is indeed a lattice, that it generalises [2] and that it is generalised by [1, 3]. – Its operational significance and, of course, – Thoughts on how it might help with constructing (secure) programs.


Abstract A once-for-life, uniform composition, blanket-free and fuel-shuffling-free reference core has been designed for the Encapsulated Nuclear Heat Source (ENHS) to provide the design goals of a nearly zero burnup reactivity swing throughout ~20 yr of full-power operation up to the peak discharge burnup of more than 100 GWd/t HM. What limits the core life is radiation damage to the HT-9 structural material. The temperature coefficients of reactivity are all negative, except for that of the coolant expansion. However, the negative reactivity coefficient associated with the radial expansion of the core structure can compensate for the coolant thermal expansion. The void coefficient is positive but of no safety concern because the boiling temperature of lead or lead-bismuth is so high that there is no conceivable mechanism for the introduction of significant void fraction into the core. The core reactivity coefficients, reactivity worth, and power distributions are almost constant throughout the core life. It was found possible to design such once-for-life cores using different qualities of Pu and transuranics as long as U is used as the primary fertile material. It is also feasible to design ENHS cores using nitride rather than metallic fuel. Relative to the reference metallic fuel core, nitride fuel cores offer up to ~25% higher discharge burnup and longer life, up to ~38% more energy per core, a significantly more negative Doppler reactivity coefficient, and less positive coolant expansion and coolant void reactivity coefficient but a somewhat smaller negative fuel expansion reactivity coefficient. The pitch-to-diameter ratio (1.45 of the nitride fuel cores using enriched N) is larger than that (1.36) for the reference metallic fuel core, implying a reduction of the coolant friction loss, thus enabling an increase in the power level that can be removed from the core by natural circulation cooling. It is also possible to design Pu-U(10Zr) fueled ENHS-type cores using Na as the primary coolant with either Na or Pb-Bi secondary coolants. The Na-cooled cores feature a tighter lattice and are therefore more compact but have spikier power distribution, more positive coolant temperature reactivity coefficients, and smaller reactivity worth of the control elements.


Drag tests on aquaculture net panels were carried out in the towing tank Lilletanken (NTNU) for fifteen current velocities. The data were post-treated and discussed in order to characterize the dependency of the drag forces on several parameters, as the solidity ratio, the Reynold number, or the nets' material and size. The behaviour of the turbulent flows around, and in the wake of the net panels has then been described. Several experiments were also achieved in model-scale for wave conditions. The resulting loads were analyzed, and the influence of the wave periods and steepness on the loads were then investigated. The study has been extended to the force amplitude harmonics, significant for high steepness. In parallel, CFD models were created in the open source software OpenFoam. They have been defined from the dimensions and properties of the experimental installation in order to produce comparable results. A convergence study was achieved to mesh 2D top and side views of the system. The twines of the nets were too small to be meshed, and were modeled thanks to a pressure drop added in the Navier-Stokes equations. The results revealed large differences between the numerical and experimental loads for high solidity ratios. The uncertainties linked to the experimental set-up have been discussed, focusing on the water elevation on the nets during the experiments, or the speed-up caused by the frames supporting the nets.


The current study was carried out on behalf of GKN Aerospace as a Master's thesis at Chalmers University
of Technology. The Department of Propulsion Engineering at this company wished to develop a deeper
understanding into the performance of supersonic engine intakes and to relate this to the in
uential physical
notions and geometry alterations. The ultimate objective was to obtain a CFD model to study the effects
of key variations of geometrical and physical parameters on the aerodynamic performance. This model was
initially to be validated on a model scale against the results of wind tunnel tests. The specific means by which
this validation was done was to compare the mass
ow and total pressure recovery at the outlet of the intake,
as predicted by wind tunnel tests and by the CFD model. The results of the validation study show that despite
the two-dimensional geometry of the intake, the
ow in the interior of the intake is highly three-dimensional.
This is mainly attributed to the separation in the subsonic diffuser, induced by shock waves and end-wall,
turbulent effects. This has highlighted distinct dierences in the means by which the global, gross effects of
total pressure recovery is estimated in wind tunnel tests as compared to the model. Nevertheless, disregarding
from the explicable differences, a sound model was achieved.
The secondary objective was to scale this generic model intake to a real size, to meet the mass
ow requirements
of a typical engine. As the scaling was performed, alterations to the external compression ramp
geometry was implemented. This was done in order to investigate the global eects of having an isentropic,
continuous-curve type ramp as compared to a discrete, two-step ramp. As the parametric study was carried
out, it was concluded that the effect of having a discrete ramp was mainly that of reducing the mass
ow
swallowed by the intake. While having comparable levels of global total pressure recovery, the discrete-ramp
geometry featured the positive effect of limiting
ow separation and distortion in the diffuser section. This
effect was attributed to the reduction in velocity and momentum of the ingested mass
ow, due to less efficient
external compression and increased mass
ow spillage. Finally, aerodynamic performance of the large-scale
intake was assessed in terms of aerodynamic drag forces and pitch torque. On the basis of the conclusions
formed in this project, some recommendations for future work were given.


In this study, three magnetometer stations in China and four co-located magnetometers and geoelectric field detectors in Japan were primarily used for observing co-seismic signatures excited by nuclear explosions conducted in North Korea between 2006 2017. The observations in Japan did not measure considerable magnitudes of the co-seismic electromagnetic (EM) signals corresponding to the geomagnetic and geoelectric fields at large distances from the explosion source. However, the geomagnetic field detectors in northeast China detected clear co-seismic signatures, shortly after the arrival time of the seismic waves. On the day of the most powerful blast on 3 September 2017, the horizontal component of the geomagnetic field with a maximum amplitude of ±5 nT was measured at the Changchun station in China, located at a distance of less than 500 km from the explosion source. In order to understand the measured signals, three mechanisms that can induce these signals were simulated. The electrokinetic and dynamo effects were observed to primarily contribute to the formation of the surface-wave-related EM signals, whereas the shaking and vibration of the instrument caused the continuous oscillation seen in the geomagnetic observations. Article history: Received 3 January 2020 Revised 29 September 2020 Accepted 24 November 2020


This paper reports on the design and development of an electronic classroom and con- ference room which was opened in the city of Linz, Austria, in late 1996. This room was devel- oped in a multidisciplinary approach and contains several unique features. After an introduction about the background, rationale for merging the concepts of classroom and conference room, and an overview about the four layers of the logical architecture, the paper emphasizes issues associated with the facilities installed. Then the attention is drawn upon a "consumables" layer which we propose to insert between such facilities and the usual software tools. A brief over- view of the tools and contents layers completes the description.


From the exponential function of Euler's equation to the geometry of a fundamental form, a calculation of the fine-structure constant and its relationship to the proton-electron mass ratio is given. Equations are found for the fundamental constants of the four forces of nature: electromagnetism, the weak force, the strong force and the force of gravitation. Symmetry principles are then associated with traditional physical measures.


On October 1, 2018, new law governing the use of employee noncompetition agreements went into effect in the Commonwealth of Massachusetts. The updated rules, a compromise between those seeking to increase worker mobility and those intent on preserving certain intellectual property protections, were the culmination of many years of legislative debate. Before the passage of the new measures, Massachusetts exemplified the type of state that tended to honor employee covenants not to compete. One scholar famously identified Massachusetts's high enforcement of noncompetes as the primary cause of the Route 128 business district's relative downfall compared to Silicon Valley, where noncompetition agreements are generally void. Time will tell whether the new noncompete legal regime will help the Route 128 region catch up to Silicon Valley's explosive growth; in the interim, as the national dispute over the merits of noncompetition agreements rages on, other states will surely look to Massachusetts before choosing whether—and how—to rewrite their employee noncompete laws. This Note examines the recent Massachusetts legislation in the context of the region's history and the broader national discussion on noncompete laws, arguing that the new rules in Massachusetts set a useful example while leaving several issues—particularly surrounding the garden leave provision and government enforcement—unresolved.


To Save the Children of Korea is the first book about the origins and history of international adoption. Although it has become a commonplace practice in the United States, we know very little about how or why it began, or how or why it developed into the practice that we see today.Arissa Oh argues that international adoption began in the aftermath of the Korean War. First established as an emergency measure through which to evacuate mixed-race "GI babies," it became a mechanism through which the Korean government exported its unwanted children: the poor, the disabled, or those lacking Korean fathers. Focusing on the legal, social, and political systems at work, this book shows how the growth of Korean adoption from the 1950s to the 1980s occurred within the context of the neocolonial U.S.-Korea relationship, and was facilitated by crucial congruencies in American and Korean racial thought, government policies, and nationalisms. It also argues that the international adoption industry played an important but unappreciated part in the so-called Korean "economic miracle." Korean adoption served as a kind of template as international adoption began, in the late 1960s, to expand to new sending and receiving countries. Ultimately, Oh demonstrates that although Korea was not the first place that Americans adopted from internationally, it was the place where organized, systematic international adoption was born.


Partial discharge (PD) testing has been used for over 60 years primarily as a method to detect aging of the stator winding insulation in motors and generators rated 6 kV and above. More recently it has also been used by some machine manufacturers as a means of assuring the quality of the insulation. The PD measuring systems in use work either in the low frequency regime (less than about 1 MHz) or in the very high frequency (30–300 MHz) range. By reference to several international standards, published work as well as some experiments described here, the advantages and disadvantages of the two approaches are reviewed. In most circumstances it is now clear that off-line PD tests should be done in the low frequency range. For on-line tests, either frequency range can be used, but with different advantages.


Abstract WeedSOFT® is a decision support system that was developed to help farmers and consultants in Nebraska with the selection of optimal weed management strategies. WeedSOFT® evolved from HERB, a bioeconomic model for soybean that was developed in North Carolina. The program is composed of four independent modules, namely, ADVISOR, EnviroFX, MapVIEW, and WeedVIEW. ADVISOR helps the user select a treatment based on maximum yield or maximum net gain. EnviroFX and MapVIEW provide environmentally relevant herbicide information and county soil maps that indicate vulnerability to groundwater contamination. WeedVIEW is a visual library of color images and line drawings of 46 common weed species. Over 500 farmers and consultants in Nebraska and adjacent states use WeedSOFT®. As a result of the current regionalization effort, the user base is expected to increase rapidly during the next 2 or 3 yr. This article explains the algorithms implemented in the current version of WeedSOFT®. Nomenclature: Soybean, Glycine max (L.) Merr.


Life cycles of diatoms in polar regions comprise various stages in which the frustules of vegetative cells are discarded. These include gametangial stages during the sexual phase and the transition to stages such as resting spores/cells or winter forms.Diatoms from untreated samples from water, deep-water, sediment traps or surface sediment were identified, counted and measured. Biogenic silica content was analysed from water and sediment traps samples. Antarctic Peninsula (AP) water column and shelf surface sediment samples were taken from an autumn cruise (ANTXVIII/5b). Greenland Sea (GS) samples were taken from 3 years' sediment trap deployments, 2 autumn and 1 summer cruise during ARKTIEFII.Proboscia inermis (21%) and Corethron pennatum (17%) dominated biomass at the AP during an autumn bloom (2.5 mgChla/m3). Massive sexual reproduction was detected in both species besides the formation of winter stages in P. inermis. Male gametes and winter forms are liberated from vegetative frustules. Eucampia antarctica winter forms were discarding the vegetative theca and rudimentary valve and Odontella weissflogii was observed only as resting spores also discarding the vegetative remnant cell wall. The latter species were present in lower numbers. At the GS Rhizosolenia hebetata f. semispina, Proboscia eumorpha and Fragilariopsis cf. cylindriformis were the only important diatom species. The former two were passing through a sexual phase in which male gametangial frustules were being discarded. R. hebetata f. semispina auxospores undergo a further transformation into R. h. f. hiemalis which discards the rudimentary auxospore wall. Sinking events of empty halves of frustules and remnants were recorded in sediment traps (GS) and observed in the surface sediment samples (AP). The comparison of the specific size-frequency distributions of the width of empty halves found sedimented with that from intact cell walls in the water column was made for both regions. The matching of these size-frequency distributions, the observation of auxospores, gametangial cells and resting cells, releasing high amounts of empty cell walls, in conjunction with the analysis of BSi profiles and BSi measurements in the trapped material provides evidence that life cycles of these big diatom species can drive the silica flux.Analysis of the constituents of diatoms in the high latitudes areas studied led to the conclusion that a large portion of biogenic silica transported to depth is directly related to the remnants of diatom life cycle stages. Consideration of these processes can help to clarify the high Si:C ratios commonly found in high latitude sinking matter.


Raised shell projections on the inner shell walls that form pits on the internal moulds of Devonian ammonoids have been known for several decades. New specimens from Morocco reveal novel details of these structures; most, if not all, of which consist of a capsule of ammonoid shell that covers tiny tubes attached to the outer (= lateral or ventral) shell wall from the inside. In accordance with comparable Recent occurrences of similar structures in molluscs, we use the term "pearls" for these structures and the pits they form on the internal moulds. The nature of these encapsulated tubes is described and discussed. Because of the presence of these tubes inside the pearls, pearl arrangement, and their similarity to Recent mollusc occurrences, the tubes are interpreted as traces of parasitoses. The pearls and pits were grouped into five types based on differences in morphology, size, and arrangement. Then, having used these traits to perform a simple cladistic analysis, the resulting cladogram was compared to the phylogeny of ammonoids. Based on this comparison, it appears likely that the parasites underwent a co-evolution with the ammonoids, which lasted 10 to 15 Ma. Patterns of evolutionary events include co-speciation, "drowning on arrival" (end of parasite lineage near base of a new host clade), and "missing the boat" (parasite lineage does not adapt to a new host clade, thus not evolving a new parasite clade). Because of the lack of fossilised soft tissue, only speculations can be made about the systematic affiliation of the parasites, their life-cycle, infection strategy, and ecological framework. Some co-occurring bivalves also have pits reminiscent to structures caused by trematodes in Recent forms. Based on the available information, the tubes are interpreted as artefacts of trematode infestations, which, if correct, would extend the fossil record of parasitic trematodes into the Early Devonian.


The multidisciplinary project AEROFIL has been defined and coordinated
with the idea of developing novel filter designs to be employed in aeronautic
hydraulic systems. The cartridge filters would be constructed using eco-friendly
filtration media supported by unconventional disposable or reusable solid
components. My main contribution to this project is the development of a robust
and cost-effective design and analysis tool for simulating the hydrodynamics in
these pleated cartridge filters. The coupled free and porous flow regimes are
generally observed in filtration processes. These processes have been the subject of
intense investigation for researchers over the decades who are striving hard to
resolve some of the critical issues related to the free/porous interfacial constraints
and their mathematical representations concerning its industrial applications. [Continues.]


In a two-part field study, we studied the communication tool use of 29 college students and 20 recent college graduates. In comparing the two groups' communication choices, we explored how transitioning from attending college to working full time impacts communication. We discuss how communication changes for recent college graduates in terms of both the content of their conversations, as well as the communication methods they use. We found that convenience plays a major role in the adoption and usage of communication tools, with participants preferring methods that were easily accessible at work, at home and in transit. We identify life changes recent graduates experience as they transition into emerging adulthood: the effect of being on a computer at work all day, changing social circles and scenes, being geographically distant from friends and family, and the desire for a professional persona. We discuss the impact of these changes on communication.


OBJECTIVE
Because treatment with tumor necrosis factor (TNF) antagonists may increase the risk of tuberculosis (TB), and because knowledge of the risk of TB in rheumatoid arthritis (RA) not treated with biologics is scarce and of uncertain generalizability to low-risk populations, this study sought to determine the risk of TB among Swedish patients with RA.

METHODS
Using data from Swedish nationwide and population-based registers and data from an ongoing monitoring program of TNF antagonists, the relative risks of TB in patients with RA (versus the general population) and of TB associated with TNF antagonists (versus RA patients not treated with biologics) were determined by comparing the incidence of hospitalization for TB in 3 RA cohorts and 2 general population cohorts from 1999 to 2001. We also reviewed the characteristics of all reported cases of TB in RA patients treated with TNF antagonists in Sweden and calculated the incidence of TB per type of TNF antagonist between 1999 and 2004.

RESULTS
During 1999-2001, RA patients who were not treated with TNF antagonists were at increased risk of TB versus the general population (relative risk 2.0, 95% confidence interval [95% CI] 1.2-3.4). RA patients treated with TNF antagonists had a 4-fold increased risk of TB (relative risk 4.0, 95% CI 1.3-12) versus RA patients not treated with TNF antagonists. The reported TB cases during 1999-2004 in RA patients exposed to TNF antagonists (9 infliximab, 4 etanercept, 2 both) were predominantly pulmonary. TB occurred up to 3 years following the start of treatment.

CONCLUSION
Irrespective of whether TNF antagonists are administered, Swedish patients with RA are at increased risk of TB. During 1999-2001, TNF antagonists were associated with an increased risk of TB, up to 4-fold in magnitude. This increased risk may persist over time during treatment and is related to both infliximab and etanercept.


The innovation of band-gap engineering in advanced materials caused by the alloying of different semiconductors into solid-solution nanostructures provides numerous opportunities and advantages in optoelectronic property tailoring. The semiconductor solid-solution nanostructures have multifarious emission wavelength, adjustability of absorption edge, tunable electrical resistivity, and cutting-edge photoredox capability, and these advantages can be rationalized by the assorted synthesis strategies such as, binary, ternary, and quaternary solid-solutions. In addition, the abundance of elements in groups IIB, IIIA, VA, VIA, and VIIA provides sufficient room to tailor-make the semiconductor solid-solution nanostructures with the desired properties. Recent progress of semiconductor solid-solution nanostructures including synthesis strategies, structure and composition design, band-gap engineering related to the optical and electrical properties, and their applications in different fields is comprehensively reviewed. The classification, formation principle, synthesis routes, and the advantage of semiconductor solid-solution nanostructures are systematically reviewed. Moreover, the challenges faced in this area and the future prospects are discussed. By combining the information together, it is strongly anticipated that this Review may shed new light on understanding semiconductor solid-solution nanostructures while expected to have continuous breakthroughs in band-gap engineering and advanced optoelectronic nanodevices.


The massive parallelism offered by Graphics Processing Units (GPUs) is now routinely exploited to accelerate computationally intensive tasks in a wide variety of application domains. Efficient GPU programming in languages such as CUDA and OpenCL requires careful application of hand optimisations to exploit parallelism and locality while minimising synchronisation. The effectiveness of such optimisations can be highly dependent on workload and the structure of input data, making it difficult to assess performance in general by testing alone. To address this, we study the problem of estimating the Worst-Case Execution Time (WCET) of GPU-accelerated applications. We propose the use of hybrid WCET analysis whereby execution times of small program segments are deduced from traces of execution and a calculation backend derived from the Control Flow Graph (CFG) produces a WCET estimate. Standard techniques which construct a CFG from a binary cannot be applied directly to GPU code because they miss implicit execution paths that arise due the way branches are implemented in hardware - we present a solution using standard compiler analysis. We further describe how to extend the basic hybrid WCET analysis of sequential code so that concurrent timing effects in the GPU execution model are incorporated. We have implemented our analysis as a tool built on top of the GPGPU-sim open source simulator. We evaluate our tool using a set of benchmarks drawn from the CUDA SDK: results show that effective modelling of concurrency is key to reducing pessimism in the WCET calculation.


This article analyses the new challenges that the ECB faces in implementing its monetary policy and asks to what extent judicial review can help address these. The ECB mandate provides no clear guidance for many of the ECB's recent challenges, which include a sovereign bond market panic, technical limits to the efficacy of its tools, and questions concerning the environmental impact of its operations. For this reason, the ECB's decisions suffer from democratic authorization gaps; it makes choices with far-reaching consequences for which there is no clear basis in the mandate. In this context, courts can either opt to accept choices made by the ECB, as the ECJ has mostly done, or, as the Bundesverfassungsgericht decided to do, itself weigh in on monetary policy. Neither approach, we argue, can improve the tenuous democratic legitimacy of the ECB in the absence of proper democratic guidance. There are, however, other ways the Member States and the EU's political institutions can provide the ECB with guidance on how to deal with its new choices.


A numerical study is conducted on the heat and fluid flow characteristics in an annulus between two concentric square ducts. Inner and outer walls are assumed to be isothermal, but at different temperatures. The flow through the annular duct is assumed to be laminar, steady, and both hydrodynamically and thermally fully developed with constant physical properties. For the Cartesian coordinate system, the governing equations are discretized by using the control volume method and are solved by the ADI method. The upwind scheme and the central difference scheme were employed to represent the convection and diffusion terms, respectively. The Stone's method was employed to solve the pressure-correction equation based on the SIMPLE Algorithm. Solutions were obtained for air (Pr=0.7). The velocity and temperature fields, the friction coefficients and Nusselt numbers are presented depending on the dimension ratio, a/b. With the increasing dimension ratio, it has been shown that the convective heat transfer is remarkably enhanced at the inner wall, while it becoming worse at the outer wall. The present results are compared with those for an annulus between two concentric cylinders and, finally, it is disclosed that the present or former geometry suggest lower heat transfer rates and friction factors


This study aims for deeper understanding of the composition and phase changes occurring during HVOF spraying of the powder to WC-CoCr coatings. Also, the effect of lamellar microstructure on the mechanical properties is studied. Compositional and microstructural features are studied by means of X-ray diffraction, XRF, FE-SEM and TEM (EDX, EELS). Mechanical properties are mainly studied by different instrumented indentation and nanoindentation techniques. The use of two new fracture parameters, complementing the fracture toughness value of the coating, are proposed and examined. Higher load range indentations are used to measure cross-sectional and surface hardness, elastic modulus and fracture toughness of the coatings. Mechanical properties of individual phases are studied by nanoindentation. To our knowledge this is the first time that the mechanical properties of this amorphous/nanocrystalline matrix are studied. ICP (In-situ Coating Property) sensor, developed for quality control and residual stress evaluation, is also used to measure the elastic modulus and coefficient of thermal expansion (CTE) of the coatings. Abrasion wear resistance of the coatings are studied according to standard ASTM G 65D.
Because of the brittle nature of HVOF coatings, the main focus of this study is in the effects of coating microstructure on fracture toughness, and on crack initiation and propagation resistance. It is shown that even when two similar coatings have equal indentation fracture toughness values, the critical crack initiation loads may be very different. This new parameter is expected to be extremely useful in the evaluation of the coating performance under loading conditions.


Abstract Flower signaling and orientation are key characteristics that determine a flower's pollinator guild. However, many flowers actively move during their daily cycle, changing both their detectability and accessibility to pollinators. The flowers of the wild tobacco Nicotiana attenuata orientate their corolla upward at sunset and downward after sunrise. Here, we investigated the effect of different flower orientations on a major pollinator of N. attenuata, the hawkmoth Manduca sexta. We found that although flower orientation influenced the flight altitude of the moth in respect to the flower, it did not alter the moth's final flower choice. These behavioral observations were consistent with the finding that orientation did not systematically change the spatial distribution of floral volatiles, which are major attractants for the moths. Moreover, hawkmoths invested the same amount of time into probing flowers at different orientations, even though they were only able to feed and gather pollen from horizontally and upward‐oriented flowers, but not from downward‐facing flowers. The orientation of the flower was hence crucial for a successful interaction between N. attenuata and its hawkmoth pollinator. Additionally, we also investigated potential adverse effects of exposing flowers at different orientations to natural daylight levels, finding that anther temperature of upward‐oriented flowers was more than 7°C higher than for downward‐oriented flowers. This increase in temperature likely caused the significantly reduced germination success that was observed for pollen grains from upward‐oriented flowers in comparison to those of downward and horizontally oriented flowers. These results highlight the importance of flower reorientation to balance pollen protection and a successful interaction of the plant with its insect pollinators by maintaining the association between flower volatiles and flower accessibility to the pollinator.


4G technology bring great prospects for the future. To obtain the desired goal, a multiplexing technique known as the OFDM i.e. Orthogonal Frequency Division Multiplexing was being suggested. OFDM provides sufficient data rate as other methods but requires less bandwidth. The idea of OFDM was conceptualized in the 60"s. Weinstein and Ebert showed that OFDM can be employed or implemented using Fast Fourier Transform (FFT). With arrival of VLSI and advancement in DSP techniques, OFDM was practically implemented. OFDM has three main problems namely Intersymbol Interference (ISI), PAPR known as Peak-to-average Power ratio and the intercarrier Interference (ICI). One of most severe problem among these is ICI. Efficient methods were proposed to eliminate the ISI and reduce PAPR. This paper explains the factors that causes ICI in the 4G LTE wireless system and possible solutions to this kind of interference. The ICI increases the system probability of bit error rate (BER) increases. The system BER can be reduced by reducing the factors which have significant affects to cause ICI. Keywords— OFDM, Multicarrier Techniques, 4G, LTE, Digital Modulation


Laboratory Animal Science is a multidisciplinary science contributing to the humane use and care of animals and to the quality of animal experiments. Animal staff, researchers and regulators strive continuously to improving welfare of animals used in research. Transportation of small laboratory rodents has thus far stayed mainly below the radar of their scrutiny. Not only does transportation directly affect the welfare of the animal, the effects of transportation on research results can lead to the wrong conclusions. Daily routine procedures with small laboratory rodents imply many stressors that cause temporary deviation from the animal's (physiological) homeostasis. In stressful situations the animal will react in a different way to a stimulus as compared to how it would react in an unstressed situation. In that sense a stressful response of the animal may therefore bias research results. Those involved in animal research are at least aware that animals need acclimatization after arriving at their facility. However, the duration of this acclimatization period is seldom based on evidence-based research, even though the experts are clear in their warnings on the effects of transportation on research results. To acquire reliable data from transferred animals transfer stress can perhaps be ameliorated by implementing an acclimatization period between arrival and onset of the study. The studies presented in this thesis were designed to measure the effects of transportation on Wistar rats, a frequently used general purpose outbred strain of rats and the duration of these effects. The results might help to optimizing the transportation and acclimatization process, to improve the welfare of the animals and increase the validity of research results. By mimicking the daily practise used in animal transfer, the studies were set up to be translatable to other research fields. By means of radiotelemetry physiological measurements were performed on heart rate, blood pressure and locomotor activity. Effects on behaviour were studied by performing home cage observations on activity, social interactions and self-grooming. Blood samples were taken to measure the effects on plasma corticosterone, glucose and creatine kinase. Also bodyweight, body temperature and environmental temperature were taken into account. Overall, the results show that transferring rats from a breeder to a research facility significantly affects their physiology and behaviour. Some parameters seem to stabilize at a level different from initial baseline, which indicates allostasis rather than homeostasis. After two weeks, parameters that stabilize, have reached their (new) baseline level. Not all parameters do stabilize within two weeks. In corticosterone we've found highly fluctuating and continuously increasing levels in female rats. Therefore we cannot consider corticosterone a reliable indicator for acclimatization in adolescent female rats. Although affected by transfer, locomotor activity shows inconsistent durations of effect. Longer acclimatization possibly leads to stabilization of locomotor activity, which should be investigated further. Based on the longest allostatic stabilization found in the combined results of all studies in this thesis, an acclimatization period of two weeks would be advisable.


Countourites are a widespread but poorly known group of sediments linked to the action of powerful bottom currents in deep water. Although we know they are especially common along continental margins and through oceanic gateways, they have been surrounded by contoversy since they were first recognized in the early 1960s. Where correctly recognized and decoded they can provide one of the keys to our better understanding of bottom water circulation and of the ocean–climate link. They are part of the spectrum of deposits that confronts the oil industry as exploration moves into progressively greater water depths.

This memoir is an important outcome of the International Geological Correlation Project 432 on Bottom Currents, Contourites and Palaeocirculation . It includes 30 papers involving over 75 key scientists from around the world. Following an introductory state–of–the–art paper by the editors, there are 25 separate case studies on modern drifts and four on ancient contourite series. Each contribution highlights the specific geological and oceanographic setting, bathymetry, physiographic and stratigraphic context, seismic attributes and sedimentary characteristics of that drift. Case studies range from some of the well-documented North Atlantic drifts to those much less known from the Mediterrenean, from important syntheses of the Gulf of Cadiz and Vema Channel Gateway, to completely new data on South Atlantic, Pacific and Antartic margin systems. The four papers on ancient series from Japan, China and Cyprus serve to emphasise the complex nature and subtle characteristics of contourites, which make their identification a scientific challenge.

This volume is dedicated to the memory of Charlie Hollister (1936–1999), one of the founding fathers and pioneers of countourite research.


This issue brings together leading specialists from diverse fields including multiple subspecialties of anesthesiology, as well as surgery, cardiology, oncology, neurology, hospital medicine, endocrinology, and others. A multidisciplinary approach is essential to patient safety and optimal outcomes, so this valuable and unique monograph brings the anesthesiologist up to date on current integrated methods of preoperative assessment, consultation, and patient preparation for surgery. The Article topics include preoperative evaluation and prep of the patient for cardiac surgery; noncardiac surgery in the patient with heart disease; identification and evaluation of the patient with lung disease; surgery on the patient with endocrine dysfunction; obesity, metabolic syndrome, and the surgical patient; surgery in a patient with liver disease; surgery in the patient with renal dysfunction; anemia in the preoperative patient; perioperative anticoagulant management; preop prep of the surgical patient with neurologic disease; and emergency and urgent surgery.


Improve your grammar with Collins Grammar for IELTS and get the score you need. IELTS is the world's leading test of English for higher education and migration and is recognised by 6000 institutions in over 135 countries. Collins Grammar for IELTS is a self-study book for learners of English who plan to take the Academic module of the IELTS test. This book is an ideal tool for learners studying at CEF level B1 or above or with a band score 5-5.5 who are aiming for a band score of 6 or higher. Twenty 4-page units present key areas of grammar with practice exercises similar to the ones in the IELTS test. Practical exam strategies and tips help you improve your IELTS score. Practice exam sections at the end of each unit allow you to familiarise yourself with the test questions. The Audio CD contains texts for Listening practice as well as model answers showing you how to use certain grammatical structures in the IELTS Speaking test. * Also available in the 'Collins English for Exams' series: - Listening for IELTS - Speaking for IELTS - Writing for IELTS - Reading for IELTS - Vocabulary for IELTS


In the last 25 years we have seen the web enable new digital means for historians to reach broader publics and audiences. Over that same period of time, archives and archivists have been exploring and engaging with related strands of digital transformation. In one strand, similar focus on community work through digital means has emerged in both areas. While historians have been developing a community of practice around public history, archivists and archives have similarly been reframing their work as more user-centered and more closely engaged with communities and their records. A body of archival work and scholarship has emerged around the function of community archives that presents significant possibilities for further connections with the practices of history and historians. In a second strand, strategies for understanding and preserving digital cultural heritage have also taken shape. While historians have begun exploring using tools to produce new forms of digital scholarship, archivists and archives have been working to both develop methods to care for and make available digital material. Archivists have established tools, workflows, vocabulary and infrastructure for digital archives, and they have also managed the digitization of collections to expand access. At the intersection of these two developments, we see a significant convergence between the needs and practices of public historians and archivists. Historians' new forms of scholarship increasingly function as forms of knowledge infrastructure. Archivists work on systems for enabling access to collections are themselves anchored in longstanding commitments to infrastructure for enabling the use of records. At this convergence, there is a significant opportunity for historians to begin to connect more with archivists as peers, as experts in questions of the structure and order of sources and records. In this essay we explore the ways that archives, archivists, and archival practice are evolving around both analog and digital activities that are highly relevant for those interested in working in digital public history.


Stochastic differential equations (SDEs) provide a natural framework for modelling intrinsic stochasticity inherent in many continuous-time physical processes. When such processes are observed in multiple individuals or experimental units, SDE driven mixed-effects models allow the quantification of between (as well as within) individual variation. Performing Bayesian inference for such models, using discrete time data that may be incomplete and subject to measurement error is a challenging problem and is the focus of this paper. We extend a recently proposed MCMC scheme to include the SDE driven mixed-effects framework. Fundamental to our approach is the development of a novel construct that allows for efficient sampling of conditioned SDEs that may exhibit nonlinear dynamics between observation times. We apply the resulting scheme to synthetic data generated from a simple SDE model of orange tree growth, and real data consisting of observations on aphid numbers recorded under a variety of different treatment regimes. In addition, we provide a systematic comparison of our approach with an inference scheme based on a tractable approximation of the SDE, that is, the linear noise approximation.


AbstractSimulated along-track ocean altimetry data were used to implement the use of a nonlinear dynamic propagator to perform three-dimensional (time and 2D space) interpolation of mesoscale sea surface height (SSH). The method is an inverse approach to processing altimetry data unevenly sampled in time and space into high-level gridded altimetry maps. The inverse approach, similar to the standard objective mapping, contains some correction terms to the innovation vectors to account for nonlinear dynamics. Another key improvement is to solve for the covariance functions through a Green's function approach. From the Observing System Simulation Experiments carried out to simulate a three-satellite constellation over the Gulf Stream region, the new method can significantly reduce mapping errors and improve the resolving capabilities compared to the standard linear objective analysis such as that used by the AVISO gridding.


The superficial effect of hardening caused after vibration-assisted ball burnishing and its consequences in the tensile behavior of a carbon steel material are studied in this paper. As ball burnishing affects the material to hundredths of micrometers in depth through plastic deformation, the overall macro effect of this modification was studied. Different levels of preload and vibration amplitude were studied to address the described issue. The study was done in two phases. First of all, the depth to which ball burnishing affects the material was studied by performing Vickers indentation tests with different loads. It was proven that the effects of ball burnishing are best represented when a 0.05 kg load is used, as higher loads include more volume of core material in the measurement, hence hiding the effect of ball burnishing. In a second phase, the ball burnished specimens were subjected to tensile tests. It was proven that an increase of burnishing preload diminishes the ductile behavior of the material and increases its strength representative values, although the proportion of affected material in the cross-section of the specimen is reduced with regard to the whole surface. Additionally, as the preload increases, the effects of assistance through vibrations is reduced, and the effect of the static preload acquires more relevance in modifying the macroscopic mechanical properties of the steel alloy. Experiments using different amplitudes and new forces are encouraged to obtain more information about how the material can be modified optimally through vibration-assisted ball burnishing.


This paper presents the case of World Bank support to the mass titling component of the Cambodia Land Management and Administration Project. This was a project for which there was clear national demand, as evidenced by the fact that the Cambodian government had already attempted to implement mass titling a decade previously, but had lacked the human and technical resources to complete it. The case describes a consensus between donors and a host nation government during the planning and approval of the intervention, which dissolves into conflict during implementation. Ultimately, the case raises questions about the ethics of intervention. When governments want approximately the rules of the game suggested by donors (functioning institutions to facilitate markets) but do not want a level playing field, how should this be understood and resolved? Must donors always be passively complicit in elite projects until domestic politics hold them accountable to their own rules?


Multidomain traffic engineering (TE) has the potential not only of guaranteeing the quality of service (QoS) to connections spanning multiple domains but also of effectively utilizing intradomain resources. The hierarchical Optical Internetworking Forum (OIF) External Network-to-Network Interface (E-NNI) control plane platform has emerged as a promising candidate aiming at guaranteeing multidomain QoS provisioning. Recent efforts have been made to extend OIF E-NNI in the multicarrier scenario. However, open issues such as confidentiality, the choice of TE metric, the routing controller (RC) architecture, the path computation method, and the abstraction schemes responsible for selecting the appropriate value of the TE metric to be announced have not been addressed yet. In this study, what we believe to be a novel RC architecture integrating the path computation element (PCE) is proposed to enable the efficient provisioning of end-to-end QoS-guaranteed services. The key role of the TE metric is analyzed and discussed, together with different TE metric abstraction schemes. The end-to-end delay is here considered as the most suitable candidate and a novel family of such schemes, named delay-bandwidth aware (DBA), are proposed and evaluated by means of simulations. Results show the ability of such schemes to globally preserve control plane stability and network resource utilization while advertising a high service level.


The functional diversity of enzyme families is thought to have been caused by repeated recruitment events--gene duplications followed by conversions to new functions. However, mathematical models show this can only work if beneficial new functions are achievable by just one or two base changes in the duplicate genes. Having found no convincing demonstration that this is feasible, we previously chose a highly similar pair of E. coli enzymes from the GABA-aminotransferase-like (GAT) family, 2-amino-3-ketobutyrate CoA ligase (Kbl2) and 8-amino-7-oxononanoate synthase (BioF2), and attempted to convert the first to perform the function of the second by site-directed mutagenesis. In the end we were unable to achieve functional conversion by that rational approach. Here we take a complementary approach based on random mutagenesis. Focusing first on single mutations, we prepared mutated libraries of nine genes from the GAT family and tested for BioF2 function in vivo. None of the singly mutated genes had this function. Focusing next on double mutations, we prepared and tested 70% of the 6.5 million possible mutation pairs for Kbl2 and for BIKB, an enzyme described as having both Kbl2 and BioF2 activities in vitro. Again, no BioF2 activity was detected in vivo. Based on these results, we conclude that conversion to BioF2 function would require at least two changes in the starting gene and probably more, since most double mutations do not work for two promising starting genes. The most favorable recruitment scenario would therefore require three genetic changes after the duplication event: two to achieve low-level BioF2 activity and one to boost that activity by overexpression. But even this best case would require about 10^15 years in a natural population, making it unrealistic. Considering this along with the whole body of evidence on enzyme conversions, we think structural similarities among enzymes with distinct functions are better interpreted as supporting shared design principles than shared evolutionary histories.