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Two opposing selective pressures have shaped the evolution of the structure of the blood-gas barrier in air breathing vertebrates. The first pressure, which has been recognized for 100 years, is to facilitate diffusive gas exchange. This requires the barrier to be extremely thin and have a large area. The second pressure, which has only recently been appreciated, is to maintain the mechanical integrity of the barrier in the face of its extreme thinness. The most important tensile stress comes from the pressure within the pulmonary capillaries, which results in a hoop stress. The strength of the barrier can be attributed to the type IV collagen in the extracellular matrix. In addition, the stress is minimized in mammals and birds by complete separation of the pulmonary and systemic circulations. Remarkably, the avian barrier is about 2.5 times thinner than that in mammals and also is much more uniform in thickness. These advantages for gas exchange come about because the avian pulmonary capillaries are unique among air breathers in being mechanically supported externally in addition to the strength that comes from the structure of their walls. This external support comes from epithelial plates that are part of the air capillaries, and the support is available because the terminal air spaces in the avian lung are extremely small due to the flow-through nature of ventilation in contrast to the reciprocating pattern in mammals.
- evolution
- pulmonary circulation
- gas exchange
- type IV collagen
- wall stress
- stress failure
- respiratory physiology
The Two Selective Pressures Affecting the Blood-Gas Barrier
One of the most critical structures for efficient pulmonary gas exchange in air-breathing vertebrates is the blood-gas barrier. After it was realized some 100 years ago that oxygen and carbon dioxide move through this barrier by passive diffusion (15), it was clear that an important selective pressure was that the barrier be extremely thin and have a large surface area. These characteristics follow immediately from the Fick diffusion equation, which states that the amount of gas diffusing across the barrier is proportional to the area of the barrier and inversely proportional to its thickness.
However, a second selective pressure, which acts as a major constraint to the thinning of the gas-exchanging barrier, has only recently been recognized. This is because, in addition to the barrier being thin and having a large area, it must have sufficient strength to resist mechanical failure in the face of the large stresses developing within it (36). These stresses arise primarily because of the transmural pressure of the pulmonary capillaries that increases when the cardiac output rises as in severe exercise. An additional factor increasing the stress under some conditions is a high state of lung inflation, where the tension in the alveolar walls increases and part of the increased stress is transmitted to the capillary walls. Even with relatively small increases in capillary transmural pressure during exercise, the wall stress associated with these can be very high because of the extreme thinness of the wall. Thus we can see immediately that the strong selective pressure to have a thin blood-gas barrier inevitably results in a propensity to develop very high wall stresses.
The purpose of this review is to discuss the interaction between these two selective pressures and, in particular, to show how the avian lung evolved a solution for the blood-gas barrier that is radically different from that in all other air-breathing lungs.
Structure of the Blood-Gas Barrier
Figure 1A shows a diagram of the typical structure of the blood-gas barrier in air-breathing vertebrates. Although the structure is relatively simple, it beautifully conforms to the two selective pressures listed above; that is, it is extraordinary thin but remarkably strong. There are only three layers: epithelium, extracellular matrix (ECM), and endothelium. The epithelium is typically covered by a thin aqueous layer that has the function of reducing the surface tension.
The epithelial layer exists because this is the interface between the organism and the air of the environment. Lungs first evolved as an outgrowth from the primitive gut, which is lined by epithelium. The endothelial layer exists because the pulmonary blood vessels derive from endoderm, and all capillaries are lined by endothelial cells. Both the epithelial and endothelial cellular layers are typically extremely thin, thus allowing efficient diffusive gas exchange.
The third layer, the ECM, is critically important for the second selective pressure, that is, maintaining the integrity of the blood-gas barrier in the face of large forces that would otherwise damage it. The cellular layers themselves are not strong. However, the basement membranes of the epithelial and endothelial cells contain type IV collagen, the fibers of which have a high ultimate tensile strength (6). The structure of type IV collagen is shown in Fig. 1B, and it is mainly confined to the center of the ECM layer, where it often shows as an electron-dense band in electron micrographs. The thickness of the type IV collagen layer is as little as 50 nm, thus combining extreme thinness with great strength. Despite its thinness, this layer is the lifeline that maintains the integrity of the blood-gas barrier and prevents the contents of the pulmonary capillaries from spilling into the air spaces.
The success of this simple design from an evolutionary point of view is seen when we compare the structure of the blood-gas barrier from the air-breathing vertebrates, including the air-breathing fishes, amphibia, reptiles, mammals, and, finally, birds. Examples are shown in Fig. 2. It is remarkable that the structure has remained so consistent over such an enormous evolutionary scale. Note that the three layers are clearly visible in all instances, and in several, the central electron-dense bands in the middle of the ECM can be identified.
The Selective Pressure to Facilitate Gas Diffusion Through the Blood-Gas Barrier
Thinness of the blood-gas barrier.
We have seen that the first selective pressure for the blood-gas barrier is that it be very thin and have a large area. In keeping with this, Fig. 3 shows that the mean thickness of the barrier decreases from amphibians to reptiles to mammals and birds in keeping with the different gas exchange needs among the different classes of vertebrates. Only the mammals and birds are homeothermic endoderms with the capability of high sustained maximal oxygen consumption. Furthermore, some birds have a higher mass-specific maximal oxygen consumption than any mammals (31), and birds often have a higher aerobic scope, that is, the increase in oxygen consumption from resting to maximal values (3). Therefore, the marked decrease in mean thickness of the barrier is in keeping with the gas exchange needs.
The data plotted in Fig. 3 are from Table 1 of Maina and West (21), which includes 34 species of birds, 37 species of mammals, 16 species of reptiles, and 10 species of amphibians. The plots show the mean harmonic thickness because the investigators who collected these data were particularly interested in the diffusing capacity of the lung for oxygen, and the mean harmonic thickness is the appropriate measurement for this. The reason is that thickness is in the denominator of the diffusion equation. The mean harmonic thickness is determined by taking the reciprocal of the mean of the sum of the reciprocals of the measurements made perpendicular to the plane of the barrier. It is perhaps not surprising that reptiles have substantially thinner barriers than amphibians, because the latter class of vertebrates uses the skin for respiratory gas exchange in addition to the lung. The fact that the thickness of the barrier is further reduced in mammals and birds is expected, because these classes are capable of much higher sustained maximal oxygen consumptions. However, the marked difference between mammals and birds is perhaps unexpected. The values of the mean harmonic thickness are 0.47 and 0.19 μm, respectively, which means that the mean thickness in these two groups differs by a factor of 2.5. Even in members of the two classes that have small body sizes, there are large differences. For example, the thickness in the violet-eared humming bird is 0.099 μm, whereas that in the shrew is 0.34 μm, a 3.4-fold difference (21). The extraordinary ability of birds to reduce the thickness of the blood-gas barrier is one of the main points of this review and is discussed below. All the mean values shown in Fig. 3 are significantly different from each other at the level of P < 0.001.
Although the differences between the mean values are so large, there are some substantial differences within each class of vertebrates. For example, within the birds, the ostrich has a mean thickness of 0.56 μm, and the value in the Humboldt penguin is 0.53 μm. However, all the values of the other birds in the group vary between 0.32 μm for the domestic fowl and 0.12 μm for the common gull. It has been suggested that the thicker blood-gas barrier in the diving birds such as penguins might help to prevent collapse of the air capillaries during dives. There also are differences within the mammals, with the domestic pig having the highest value at 0.72 μm and the ground mole rat having the lowest value at 0.20 μm. However, despite these appreciable differences within each class of vertebrates, the standard errors as shown by the bars are very small.
Surface area of the blood-gas barrier.
In contrast to the highly conserved structure of the blood-gas barrier, as shown in Fig. 2, and the relatively small variation in the thickness of barrier within each vertebrate class, as shown in Fig. 3, the surface area of the barrier changes enormously between species (24). The surface area of the barrier is closely related to the size of the lung, and obviously this varies greatly both within and between classes of vertebrates. Gehr et al. (11) documented the strong relationship between the surface area of the barrier and the body mass of mammals. For example, the surface area varies from ∼0.02 to over 1,000 m2 between the smallest shrew and the horse. It is this very large difference in surface area that enables the much higher maximal oxygen consumptions of the big mammals compared with the small ones. In other words, the enormous differences in maximal oxygen consumption between animals of different body size are made possible not by changes in the structure or thickness of the blood-gas barrier but by the large changes in surface area.
There also are differences between the classes of birds and mammals. Birds have about a 15% larger surface area of the blood-gas barrier compared with mammals of the same body mass despite the fact that the volume of the gas-exchanging tissue in the bird parabronchi is much smaller than that in the mammal (19). This is made possible by the tight packing of the pulmonary capillaries in the avian parabronchi. Reptiles and amphibia have relatively small surface areas of the blood-gas barrier, ∼10 cm2/g body mass within the range of 10–100 g (24). This is a factor of about 10 less than that in many mammals. These numbers are consistent with the fact that the lungs of reptiles and amphibia are less finely divided, and the air spaces are much larger than in mammals (28).
The Selective Pressure to Maintain the Mechanical Integrity of the Blood-Gas Barrier
Strength of the blood-gas barrier.
So far we have considered the structure, thickness, and surface area of the blood-gas barrier, because these are the important factors for the first evolutionary pressure that allows adequate amounts of gas to diffuse between the air and blood. We now turn to the second selective pressure, that is, the features that allow the integrity of the barrier to be sustained in the face of large mechanical forces that would otherwise damage the barrier.
Available evidence indicates that the strength of the barrier comes from the ECM, particularly the type IV collagen within this, as shown in Fig. 1. For example, if the capillary transmural pressure is increased to high levels in experimental lung preparations, electron micrographs show disruptions in the epithelial and endothelial layer, but the ECM generally remains intact (36). Furthermore, it has been shown that the elastic properties of isolated rabbit renal tubules are determined by the ECM (35), and the same is true of the distensibility of capillaries in frog mesentery (26). In addition, the thickness of the ECM of capillaries in the systemic circulation increases down the body along with the transmural pressure, and this is particularly well seen in a giraffe (43). In all these examples, the ECM has a critical role.
The structure of type IV collagen is shown in Fig. 1B. The COOH-terminal end of the molecule has an EC1 globular domain that enables two of the 400-nm-long molecules to join to form a doublet. The NH2 terminus has a 7S domain that enables four doublet molecules to form a matrix configuration somewhat like chicken wire. The 7S domain links with integrins α1β1 and α2β1 (13). The total collagen IV layer, as shown in parts of Fig. 2, may have a thickness of only 50 nm, which means that the layers that look like chicken wire or chain-link fence are stacked above each other to give great strength combined with some porosity.
Few measurements of the ultimate tensile strength of type IV collagen fibers are available, but measurements of basement membrane from the lens capsule of cat (6) indicate an ultimate tensile strength of ∼1–2 × 106 N/m2, a very high value that approximates that of nonreinforced concrete. Extrapolation of measurements from isolated rabbit renal tubules gives values that are consistent with this finding (21, 35).
Stresses in the blood-gas barrier.
Figure 4 is a diagram showing the two principle stresses to which the blood-gas barrier is potentially exposed. First, there is a hoop or circumferential stress that results from the difference of pressure between the inside and the outside of the capillary in accordance with the Laplace relationship. If the capillary is regarded as a thin-walled cylindrical tube, the stress S is given by Pr/t, where P is the transmural pressure, r is the radius of the capillary, and t is the thickness of the load-bearing structure. Calculations of the tensile stress in the type IV collagen layer in the pulmonary capillaries of humans during intense exercise suggest that they approach the values for the ultimate tensile strength cited above (38).
A second cause of wall stress occurs if the lung is inflated to high volumes. The increased longitudinal tension of the alveolar wall is partly transmitted to the capillaries that basically make up the wall. It has been shown that for a given capillary transmural pressure, inflating the lung to the high volumes in experimental preparations causes ultrastructural damage to the wall (7). Because the parabronchial structures do not change volume during respiration, this potential cause of increased stress in the blood-gas barrier is avoided.
Stress failure of the blood-gas barrier.
There is experimental evidence that if the transmural pressure of pulmonary capillaries is raised to high levels in mammalian preparations, ultrastructural changes in the blood-gas barrier occur. Typically, these are breaks in the alveolar epithelium and capillary endothelium, and less commonly, in the ECM itself. In experimental rabbit lungs, the first signs of stress failure are seen at a capillary transmural pressure of ∼25 mmHg, and the number of breaks increases steadily up to a pressure of ∼50 mmHg (30). These pressures are in the same range as those calculated to occur in the human lung during heavy exercise (38).
Stress failure of the barrier is known to occur under some physiological conditions. The most striking example is so-called exercise-induced pulmonary hemorrhage in thoroughbred racehorses. Tracheal washings from these animals contain hemosiderin-laden macrophages, indicating that essentially all of these horses in training are bleeding into their lungs (41). The reason for the stress failure is that these animals have been selectively bred for high aerobic performance over hundreds of years, and their cardiac outputs are so high that the filling pressures of the left side of the heart are enormous. The result is that the pulmonary capillary pressure may approach 100 mmHg (37).
It is also known that elite human athletes lose the integrity of their blood-gas barriers during very high levels of exercise. For example, top-level cyclists who exercise close to their maximal oxygen consumption for a few minutes subsequently show a higher concentration of red blood cells in their alveoli than sedentary controls who do not exercise. The red cells are detected using bronchoalveolar lavage whereby small amounts of saline are injected into the alveolar spaces via bronchoscopy and subsequently recovered. The increased concentration of red blood cells is accompanied by abnormally high concentrations of total protein, albumin, and leukotriene B4 (12).
Many pathological conditions in humans cause stress failure of the blood-gas barrier when the pulmonary capillary pressure becomes abnormally high. These conditions include high-altitude pulmonary edema (27) and various cardiac diseases. There also is evidence of damage to the blood-gas barrier if the lung is inflated to high volumes in the intensive care unit (4) and also in diseases where the type IV collagen is weakened, such as Goodpasture's syndrome (42).
Separation of the pulmonary circulation from the systemic circulation.
So far in this discussion of the selective pressure to maintain the integrity of the blood-gas barrier, the emphasis has been on the strength of the barrier, including the stresses to which it is subjected and the consequences if these are too high. Another important evolutionary strategy has been to maintain a sufficiently low pressure in the pulmonary capillaries so that high hoop stresses could be avoided. This is thought to be one of the major reasons for the development of a separate pulmonary circulation.
As vertebrates evolved from heterothermic ectotherms as in amphibia and reptiles to the homeothermic endothermic mammals and birds, not only did the maximum oxygen transfer by the lung increase, but the means of delivering the oxygenated blood to the peripheral tissues had to be greatly raised. The consequent high cardiac outputs inevitably result in increased pressures in the outflow tract from the heart. For example, the mean aortic pressure in many mammals is ∼100 mmHg and is even higher in birds. Therefore, it became increasingly important to protect the pulmonary capillaries from the high pressures.
In fishes, where the heart is composed of a single atrium and single ventricle, blood is pumped to the gills via the ventral aorta, and from there it is distributed to the rest of the body by the dorsal aorta. In this arrangement the hydrostatic pressure in the gill capillaries must exceed that in the dorsal aorta. As an example, in the albacore tuna (Thunnis alalunga), the mean dorsal aortic pressure has been reported as high as 79 mmHg (1). Therefore, the pressure in the fish gills is much higher than can be tolerated without stress failure in some mammals. This necessitates a thicker capillary wall in tuna than in mammals.
In the evolutionary progression toward endothermy in mammals and birds, a gradual separation of the pulmonary circulation from the systemic circulation occurs (5). Complete separation is only seen in the mammals and birds, and as a result, these two classes of vertebrates are the only ones capable of sustained very high oxygen consumptions. In the modern amphibian, for example, the frog, the beginnings of the separation of the two circulations can be seen in that there are two atria but only one undivided ventricle. Nevertheless, there is some streaming of blood within the heart with the result that much of the better oxygenated blood from lungs finds its way into the aorta. This preferential distribution of blood from lungs to the peripheral tissues is another major benefit resulting from the two separate circulations. This benefit is in addition to the need to limit the hydrostatic pressure in the pulmonary capillaries.
Although this streaming of blood is advantageous in terms of oxygen delivery, the pulmonary capillaries are still exposed to a relatively high pressure because the ventricle is undivided. It is only because these ectothermic animals have relatively low maximum oxygen consumptions that the blood-gas barrier need not be as thin as it is in mammals and birds (Fig. 3). In addition, amphibia have the advantage that much of the gas exchange occurs through the skin, which is therefore a second gas-exchanging organ. In fact, in amphibia, the outflow from the undivided ventricle goes to a pulmocutaneous artery, which in some species allows the flow to be preferentially directed to either the lung or the skin.
Further separation of the two circulations is seen in the noncrocodilian reptiles such as snakes, where there are two atria and now the ventricle is partially divided. This arrangement improves the streaming of blood so that, from the point of view of gas exchange, there is now a rudimentary double circulation. However, the fact that the ventricles are undivided means that the pulmonary capillaries are exposed to the high pressures.
The monitor lizard (Varana exanthematicus) provides an interesting variant. There is a ridge in the ventricle of this animal that separates the two outflow tracts to the lungs and the rest of the body during systole. The result is that the pressure in the pulmonary artery is lower than in the aorta because of the resistance to flow caused by the ridge (2). Pulmonary gas exchange is therefore facilitated, allowing unusually high oxygen consumptions, and the blood-gas barrier is protected from the high systemic pressures, which otherwise might cause stress failure.
Crocodilian reptiles differ from noncrocodilian in that they are the first animals in the evolutionary line that do not have a right-to-left communication in the heart. However, there is a shunt between the pulmonary artery and aorta with the result that the pressure in the pulmonary capillaries is normally the same as that in the systemic pressure. The shunt also allows diversion of the right ventricular output to the aorta, causing a shunt around the lung during diving (40).
The highest sustained maximal oxygen consumptions are seen in mammals and birds, and it is therefore necessary that the walls of the pulmonary capillaries be extremely thin (Fig. 3). This in turn means that the pressures in the capillaries need to be much lower than those in the systemic circulation to avoid stress failure of the blood-gas barrier. There is no other solution to providing an extremely thin blood-gas barrier than completely separating the pulmonary and systemic circulations.
It is fascinating that intrauterine development of mammals shows some similarities with the progression of changes on an evolutionary scale as discussed above. In the human fetus, for example, the aorta and main pulmonary artery are connected by the large, short ductus arteriosus. This anatomy has similarities to that of amphibia and most noncrocodilian reptiles in that in the fetus, both ventricles discharge into what is essentially a common conduit. However, it is interesting that, as in amphibians and reptiles, some streaming of blood occurs within the fetal heart. It transpires that much of the best-oxygenated blood from the placenta that arrives in the heart from the inferior vena cava does not leave the heart through the pulmonary artery, but rather crosses the right atrium to the left atrium through the patent foramen ovale. From there, it is mainly distributed to the head and brain. By contrast, the more poorly oxygenated blood in the superior vena cava is mainly streamed to the right ventricle so that part of it reaches the lung whereas much enters the descending aorta.
Nevertheless, despite this streaming of blood that improves oxygenation of the brain, the pressure in the pulmonary artery is as high as that in the aorta because of the large shunt through the ductus arteriosus. It would be natural to expect this high pressure to cause stress failure of the walls of the pulmonary capillaries. This is avoided by having a high resistance in the small pulmonary arteries, which have large amounts of vascular smooth muscle. As a consequence of this high pulmonary vascular resistance, only about 15% of the cardiac output reaches the lungs, and the pressure in the pulmonary capillaries is kept low. Naturally, the blood flow to the lung need not be high as in the adult, because all the gas exchange occurs through the placenta, and the only function of the pulmonary blood flow is to provide for nutrition to the developing lung.
At birth, radical changes occur in the circulation. Because the lung now replaces the placenta for gas exchange, it is necessary to provide a rapid increase in pulmonary blood flow. This is brought about by a large fall in pulmonary vascular resistance, mainly as a result of the release of hypoxic pulmonary vasoconstriction when the newborn baby takes its first breaths. At the same time, the patent ductus arteriosus begins to close, thus reducing the amount of shunted blood. It is remarkable that this complicated series of events occurs so successfully in the majority of births. Incidentally, the vulnerability of the fetal pulmonary capillaries has been demonstrated by showing that the pulmonary capillaries in newborn rabbit lung are more fragile than in the adult and therefore more liable to stress failure (8, 9). A possible reason for the fragility of the capillaries is that they are exposed to such a low pressure during most of fetal life. It is known that the thickness, and therefore presumably the strength, of the blood-gas barrier undergoes remodeling in response to changes in capillary hydrostatic pressure (22).
The Unique Avian Solution for the Blood-Gas Barrier
Extreme thinness of the barrier.
The extreme thinness of the blood-gas barrier in birds was discussed in relation to Fig. 3, where we showed that the mean harmonic thicknesses for a large group of birds and mammals differs by a factor of 2.5. Figure 5 shows electron micrographs from the lungs of chicken (Gallus gallus; A) and dog (Canis familiaris; B), and the much thinner barrier in the bird is immediately evident. Studies of the total thickness of the barrier and also the thicknesses of the endothelial, ECM, and epithelial layers have been carried out in our laboratory comparing chicken, rabbit, dog, and horse lungs (33). The total thickness of the avian blood-gas barrier is much less than that for mammals, as would be expected from Fig. 3, but in addition, the thicknesses of each of the three layers making up the barrier is also much less in the chicken. The most obvious differences are in the ECM thickness, where the values for chicken, rabbit, dog, and horse are 0.045 ± 0.02, 0.174 ± 0.23, 0.319 ± 0.51, and 0.386 ± 0.64 μm, respectively. In other words, the ECM is seven times thicker in the dog than in the chicken.
This finding of an extremely thin ECM layer in the bird is paradoxical because, as discussed earlier, there is strong evidence that the strength of the blood-gas barrier comes from the ECM layer, and flying is a very energetic activity. For example, Butler et al. (3) found that pigeons flying in a wind tunnel increased their oxygen consumption from 20.3 at rest to 200 ml·kg−1·min−1, and this was accompanied by a rise in cardiac output from 555 to 2,410 ml·kg−1·min−1. Peters et al. (25) in similar studies reported an increase in oxygen consumption from 17.8 to 310 ml·kg−1·min−1, while cardiac output increased from 303 to 2,244 ml·kg−1·min−1. Therefore, it is surprising that the integrity of the blood-gas barrier can be maintained with such a thin ECM layer in the face of a high metabolic rate that is presumably associated with high pulmonary capillary pressures.
Uniform thickness of the blood-gas barrier.
Further inspection of Fig. 5 shows another important difference between the blood-gas barriers of the chicken and dog. The blood-gas barrier in the chicken is extraordinarily uniform in thickness in addition to being very thin. By contrast, in the dog, there is considerable variability in the thickness of the blood-gas barrier. It is well known that the pulmonary capillaries of mammalian lungs tend to be "polarized" in the sense that one side of the barrier is very thin but the other is much thicker. On the thin side, the barrier consists only of the alveolar epithelial cell, capillary endothelial cell, and the interstitial layer, the last being made up of the fusion of the two basement membranes. By contrast, on the thick side, the interstitium includes fibrils of type I collagen and even occasional cells, such as fibroblasts (34). We have documented the much smaller variation in the thickness of the blood-gas barrier in the chicken compared with that in rabbit, dog, and horse by calculating the coefficient of variation of the total thickness of the barrier (33). The measurements show that the coefficient of variation in the chicken is less than one-half the value found in the dog, for example.
The fact that the pulmonary capillary of mammals is polarized, that is, that one side is considerably thicker than the other, has important implications for the efficiency of diffusive gas exchange. Gehr et al. (10) reported that approximately one-half the total surface area of the blood-gas barrier in the human lung was located on the thick side of the pulmonary capillaries. This means that about 50% of the blood-gas barrier is inefficient for diffusion. Clearly, the arrangement in the bird is much more efficient.
What is the reason for the thick side of the pulmonary capillary in the mammalian lung when this is so deleterious for overall diffusive gas exchange? The answer is that a type I collagen cable extends all the way from one end of an alveolar wall to another, and in doing so, it must pass through one side of the capillaries that are strung out along the alveolar wall (34). This cable is apparently necessary to maintain the integrity of the alveolar wall, and perhaps the capillaries themselves, and is shown diagrammatically in Fig. 6. The cable is a required mechanical support system for the delicate alveolar walls that extend over such a large distance.
External support of avian capillaries.
A major difference between avian and mammalian lungs is the environment of the pulmonary capillaries. Figure 7 shows that whereas in mammals the pulmonary capillaries are strung out along the alveolar wall, and are therefore essentially unsupported at right angles to the wall, in the avian lung the capillaries are nested in a honeycomb-like structure of air capillaries. In other words, birds are unique among air-breathing vertebrates in that the capillaries are supported from the outside as well as by the intrinsic structure of their walls. The hypothesis is that these outside supports contribute to the mechanical integrity of the capillary and thus allow the blood-gas barrier to be much thinner and more uniform than in mammals.
Nature of the external support of the pulmonary capillaries.
As discussed above, the avian blood-gas barrier is very thin and uniform in thickness compared with that in mammals, and yet the exercise levels, and therefore presumably the pulmonary capillary pressures, in birds are high. This must mean that the barrier has additional mechanical support. However, the micromechanics of how the capillary walls are supported by their surrounding structures are unclear. Since the only tissue around the capillaries consists of the air capillaries (Figs. 5 and 7A), these seem to be the only candidates. The components of the air capillaries connected to the outside of the pulmonary capillaries are the epithelial bridges or plates that form the walls of the air capillaries. As Fig. 8 A shows, these bridges are extraordinary thin, only ∼50 nm in thickness in some places, and as Fig. 8B indicates, they consist of plates that connect with the walls of adjacent blood capillaries. A short Supplemental Video clarifies the structures shown in Fig. 8B. (Supplemental data for this article is available online at the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology website).
At first sight it might seem unlikely that such thin structures could provide sufficient mechanical support. To resist outward displacement of the blood capillary wall by the transmural pressure, the bridges would have to be strong in compression. However, with a wall thickness of only ∼50 nm, it seems unlikely that this could be the case. We would expect such thin sheets to buckle under a compressive load. On the other hand, the geometrical arrangement of the epithelial plates is complicated, and there may be some sharing of the loads that is not apparent. Figure 9, A and B, contrasts the mechanical support of mammalian and avian pulmonary capillaries. In mammals, the capillaries are unsupported at right angles to the alveolar wall. By contrast, in birds, the capillaries are supported on the outside by epithelial plates that form part of the air capillaries.
Perhaps the answer to how the blood-gas barrier is supported lies in the junction where the sheet makes its connection to the wall. Figures 5, 7, and 8, A and B, show an expansion of the bridges at the sites of connection to the capillary wall. If this tissue is strong in tension along the line of the junction, it would act as an additional support to prevent failure caused by hoop stress in the capillary wall. An analogy is a coarse net made of nylon that is wrapped around a rubber bulb containing a high gas pressure. The cords of nylon in the net support the wall of the rubber bulb, preventing it from expanding. In this way, the hoop stresses in the wall of the bulb are not allowed to increase. In effect, the high stresses are transferred to the nylon net. This arrangement would work best if the linear junctions between the plates and the capillary wall were numerous and also oriented in different directions like the net referred to above. We do not yet have enough information on the three-dimensional geometry at the electron microscopy level to know whether this is the case.
It should be pointed out that just because structures such as the epithelial plates, or their junctions with the capillary walls, are very thin does not necessarily mean that they cannot sustain substantial mechanical loads. It may be that the loads are shared in an efficient manner that we do not as yet understand. A possible analogy is the spokes of a bicycle wheel that individually are only a few millimeters in diameter but together can support a load on the wheel of perhaps 50 kg.
Another possible factor that might help to sustain the mechanical loads is the surface tension in the air capillaries. These surface tension forces could be very high, because the radius of curvature of the air capillaries is only ∼5–10 μm. It is easy to imagine that a network of such structures with a high surface tension could be very rigid, and in fact, the parabronchial tissue of duck lung has been shown to be very resistant to compression (16). We have almost no information on the possible role of surface tension, although it is known that bird lungs contain surfactant and also another trilaminar lipoprotein structure, the function of which is unclear (14, 23). The lipoprotein is located on the epithelial bridges (14).
Finally, it should be noted that in some places two blood capillaries, or even more, abut each other, as shown in Figs. 5 and 6A, and this will confer some mechanical support. However, this geometry also reduces the area of the blood-gas barrier available for gas exchange.
Reason for the small terminal air-spaces in the avian lung.
The support to the pulmonary capillaries in the avian lung comes about because the terminal air spaces, that is, the air capillaries, are very much smaller than the terminal air spaces of the mammalian lung, that is, the alveoli. What is the reason for this? The answer is the flow-through pattern of ventilation in the avian lung in contrast to the reciprocating ventilation of the mammalian lung. Extensive reviews of the air flow system in birds are available (see, for example, Ref. 19). In the mammal, a small tidal volume of ∼0.5 liter in humans is delivered into a large resting volume of the lung of perhaps 3.5 liters. Despite this small inspired volume, some of the fresh gas must travel to the periphery of the lung through a complicated process of convection and diffusion. This necessitates relatively large terminal air spaces that provide little resistance to flow. By contrast, the avian lung with its flow-through system means that the air can be pumped by the air sacs through the tiny air capillaries. This is the essential difference that contributes to the much more efficient blood-gas barrier in the avian lung.
Perspectives and Significance
The main purpose of this brief review is to elucidate the two separate selective pressures that have shaped the evolution of the structure of the blood-gas barrier in air-breathing vertebrates. The first pressure, which is that the barrier has to be extremely thin and have a large area, is well known and indeed was recognized 100 years ago. The review points out that the avian lung has been particularly successful in this respect in that the blood-gas barrier is generally much thinner than that in mammals. In addition, the thickness of the avian barrier is much more uniform than that in mammals, and these two characteristics are advantageous for gas exchange by passive diffusion.
The second selective pressure has only recently been recognized. This is the requirement to maintain the mechanical strength of the barrier in the face of its extreme thinness. The factors causing tensile stresses in the barrier are discussed, the most important of these being the hoop stress that arises because of the capillary transmural pressure. The primary material responsible for the strength of the barrier is believed to be the type IV collagen in the ECM between the alveolar epithelium and capillary endothelium. An important factor minimizing the hoop stress in the barrier in birds and mammals is the complete separation of the pulmonary and systemic circulations. Indeed, this separation is essential for the development of the high sustained oxygen consumptions seen in birds and mammals, where a very thin blood-gas barrier is mandatory.
A unique feature of the avian lung is that the pulmonary capillaries are supported by epithelial plates that are part of the air capillaries in the parabronchial tissue.. The precise way in which the tissues surrounding the pulmonary capillaries allow the blood-gas barrier to be so thin and so uniform is not understood. Possible mechanisms include mechanical support by the epithelial plates themselves or mechanical support arising from the junctions of the epithelial plates with the capillary walls. These junctions show expansions of tissue that may reinforce the capillary wall like a nylon net around a rubber bulb and thus share the hoop stresses. It would be valuable to have more information on the three-dimensional microanatomy of the epithelial bridges and plates and their mode of junction with the walls of the capillaries.
Finally, it is pointed out that this unique support of the avian pulmonary capillaries that allows the blood-gas barrier to be so thin and uniform comes about because of the different modes of ventilation in avian and mammalian lungs. Because the avian lung has separated the gas-exchanging and ventilating functions, the air spaces surrounding the avian pulmonary capillaries are very small air capillaries that are available to supply mechanical support. This is in contrast to the situation in mammalian lungs, where the pulmonary capillaries are strung out along the alveolar walls and are unsupported at right angles to the walls. Nature has produced a more efficient respiratory system in birds than in mammals.
This work was supported by National Heart, Lung, and Blood Institute Grant R01 HL 60968.
No conflicts of interest are declared by the author(s).
I thank Zhenxing Fu for assistance and the UCSD National Center for Microscopy and Imaging Research and Director Mark Ellisman for the electron tomography.
- Copyright © 2009 American Physiological Society


text:
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subset: commoncrawl


text:
Jimmy D's Car Care Center
Review for Jimmy D's Car Care Center
KATHY A. on 11/03/2015
"Honest & Reliable"
My brakes were making a "noise", so took it to the place I trust. They checked it out & assured me there were no concerns. Drove away with no worries.
Vehicle: Chevrolet Aveo
Service Date: 11/02/2015
Review Created: 11/03/2015 04:14 PM


text:
HLA, the High-Level Assembler lets you write true low-level code
while enjoying the benefits of high-level language programming.
WWW: http://webster.cs.ucr.edu/AsmTools/HLA/
make generate-plist
To install the port: cd /usr/ports/lang/hla/ && make install clean
cd /usr/ports/lang/hla/ && make install clean
A package is not available for ports marked as: Forbidden / Broken / Ignore / Restricted
PKGNAME: hla
ONLY_FOR_ARCHS: i386
SHA256 (hla/hlasrc.zip) = 733c6a9c1ba5b1099e74d2d2b8a9c6582b9871e1ba8279e4df1dd3d302a3c59e
SIZE (hla/hlasrc.zip) = 7387630
SHA256 (hla/bsd.hla.tar.gz) = fedafa5551a483ee01c3a4f8a21dc71e2d055d3e86c21cc4317495faa769b472
SIZE (hla/bsd.hla.tar.gz) = 8068509
SHA256 (hla/HLARef_html.zip) = d316833db51a52b47ea3332dfe4e428e253ce33bcd4444a8ce6f5d5cac70af54
SIZE (hla/HLARef_html.zip) = 251672
SHA256 (hla/HLAstdlib_html.zip) = e9010a755acbcdc88d42d3c10c6e48455665d0fa45f8306defcb2f0eed71e31d
SIZE (hla/HLAstdlib_html.zip) = 7399757
SHA256 (hla/lex.yy.c) = bb18f933b161af0cd4d9dee79c84fe010cfa06cd9d34524bd3c8967a908d3a6a
SIZE (hla/lex.yy.c) = 842708
SHA256 (hla/hello.hla) = 661e6f88d870431a49db6ded8aaabf37cc4ab20e5f49f130615e6bb86ece8a4c
SIZE (hla/hello.hla) = 139
NOTE: FreshPorts displays only information on required and default dependencies. Optional dependencies are not covered.
===> The following configuration options are available for hla-1.103:
DOCS=on: Build and/or install documentation
TEST=off: Build and/or run tests
===> Use 'make config' to modify these settings
bison dos2unix zip:infozip
Number of commits found: 16
- Always accompany OSVERSION check with OPSYS check
Approved by: portmgr blanket
Update to 3.0.4
- Add LICENSE
- Use USES=localbase
- Use PORTDATA
- Sort PLIST
Changes: http://git.savannah.gnu.org/cgit/bison.git/tree/NEWS
Differential Revision: https://reviews.FreeBSD.org/D9073
Exp-run by: antoine
Cleanup no longer needed CHMOD usage after r424898.
Submitted by: mat
Exp-run by: antoine
Sponsored by: Absolight
- Switch to options helpers
- Fix wrkdir permissions
lang/hla: store all distfiles at my place
Fix build as a user.
Sponsored by: Absolight
Cleanup plist
Stage, unbreak without gcc, and introduce a TEST option.
Reset maintainership for ports not staged with no pending PR
With hat: portmgr
Convert l* to USES=zip
Add NO_STAGE all over the place in preparation for the staging support (cat:
Convert USE_BISON to USES= bison
It brings bison as a build dependency in case it is set the following way:
USES= bison or USES= bison:build
it brings bison as a run dependency in case it is set the following way:
USES= bison:run
it brings bison both as a run and build dependency in case it the set the
following way:
USES= bison:both
While here trim some headers
Convert some USE_GNOME= gnomehack to USES= pathfix
- remove MD5
- Fix extraction of HTML documentation
Reported by: PH via erwin
- Update to 1.103
- Switch to the native version of HLA's stdlib
- New port: hla
High Level Assembler (HLA) is an assembly language developed by Randall Hyde
which can use high-level language constructs to aid x86 assembly programmer
beginners and advanced assembly developers alike.
Servers and bandwidth provided byNew York Internet, SuperNews, and RootBSD
No vulnerabilities have been reported in the past 14 days
* - modified, not new
All vulnerabilities


text:
Bold labels are required.
The use of the Internet or this form for communication with the firm or any individual member of the firm does not establish an attorney-client relationship. Confidential or time-sensitive information should not be sent through this form.
Privacy Policy
James L. English, P.C.
421 South Tejon Street, Suite 301
Colorado Springs,
Phone: 719-602-5662
Fax: 719-633-1091
Colorado Springs Law Office Map


text:
The final 250 kilometre race takes place tomorrow at 15.15 ACST.
It was a day that promised much but didn't deliver for Team BOC's Jason Bright in the first two races at the Clipsal 500 in Adelaide.
Red Bull's Jamie Whincup took out the race with team mate Lowndes second and Shane Van Gisbergen third.
Jason Bright Race one: "I felt as though we could get a little bit further up. We had the speed in the car but I didn't want to take too many risks there toward the end behind Scott and Rick (Kelly). Being the first race of the year and with another an hour later, I mean, if it was for the championship it would've been another story but at this stage it just wasn't worth it."
Race two started well, with Bright holding on to fourth place off the grid. With an early pit stop planned things looked good for the Team BOC driver. Unfortunately wheel gun problems robbed Bright of any hope of a strong result, dropping him from 3rd to 21st.
Following a safety car brought out by debris from James Courtney's damaged HRT passenger side door, Bright clawed back some positions but a technical issue with the car brought a halt to any meaningful comeback and Bright finished in 21st.
Red Bull's Craig Lowndes took out the win from the Volvo of Scott Mclaughlin with champion Jamie Whincup finishing third.
Jason Bright Race two: "We've had a quick car all weekend and haven't come out of today with as many points as we hoped but there's always tomorrow and we need to really get a good result. The pitstop was disappointing but something else broke on the car so I don't think we could've held on to fourth. We've got the speed, we've got the tyre life and as long as we qualify well and stay out of trouble we'll be right tomorrow."
The final 250 kilometre race takes place tomorrow at 15.15 ACST.
Team BOC


text:
Order Test Kit
All AVISE® testing is completed in our CAP accredited, state-of-the-art laboratory in San Diego, CA. Each test must be submitted in a customized AVISE® Test Kit by a physician and delivered to us via priority overnight FedEx (on our dime!).
To order test kits for your practice, please fill out the simple form below:
Thank you for your support, your kits will arrive within 5 business days.


text:
Year Established:2011
Business Type:
Management Certifiation:
It is one of the newest energy recycle machine which has important use for the energy industry.
This ball press machine is used to make coal briquette (sawdust charcoal briquette) into different shapes like square, round, stick, ball and so on.
The raw material comes form small size metal powder, waste coal dust, coal clay in storage and so on. With this machine, the waste coal chunk can be made into briquettes to recycle.


text:
Now a candidate, Rice resigns as corruption panel co-chair
Now that her candidacy in the 4th Congressional District is official, Democrat Kathleen Rice has resigned as co-chair of Gov. Andrew M. Cuomo's special commission to investigate public corruption.
In a letter Wednesday to Cuomo, Rice, the Nassau district attorney, writes that, "as I announce this week that I am seeking a new public office, I find it crucial to insulate and safeguard the Commission's work from potential distractions posed by a high-profile political campaign involving one of its senior members."
Rice has helped lead the Moreland Commission panel since last July in its investigations of potential New York election law violation. She wrote to Cuomo that she believed the commission's work "has helped to give New Yorkers an historic opportunity to demand and shape the vital reforms we need to restore trust in our state's political system."
Cuomo's panel late last year issued a preliminary report of what it called the "pay to play" culture in state government. It found examples of alleged wrongdoing involving state grants, campaign contributions and reimbursements to lawmakers and recommended publicly financing campaigns to limit the influence of big donors, closing loopholes that now allow companies to ignore the current state contribution limits and toughening penalties for bribery.
Rice had said that investigations would continue in 2014.
With Yancey Roy


text:
Los Angeles Performance Practice presents
Sat. October 7, 2017
Doors: 7:30 pm / Show: 8:00 pm (event ends at 9:00 pm)
Bootleg Theater
Los Angeles, CA
October 7 & 8 // 8:00p
October 8 // 3:00p
"A unique choreographic voice, creating work that is meditative, introspective, haunting, and ... dream-like." —SeeDance
MARSHMALLOW SEA, the latest evening-length work from choreographer Stephanie Zaletel and her company of six dancers, reflects on water and its symbols to explore fluidity and force, sustenance and submission. Zaletel dives beyond linear narratives and submits to dream logic, offering an overwhelming surge of memories disrupted by a staggered, fractured pace.
Composer Jonathan Snipes performs his score live, utilizing MaxMSP, field recordings and modular synth to construct a sonic atmosphere of persistence.
Costumes by Amabelle Aguiluz and set design by prolific recycling artist Clare Graham.
MARSHMALLOW SEA is presented as part of the 5th annual Los Angeles Exchange (LAX) Festival, produced by Los Angeles Performance Practice.https://www.bootlegtheater.org/event/1541012/
With performances and events that are geographically focused in and around Downtown L.A., the Festival program hosts ten days of contemporary performance by Los Angeles-based artists, presented in dialogue with works by guest artists from beyond our borders.
Produced by Los Angeles Performance Practice, this year's festival is made in collaboration with our partnering venues:
Bootleg Theater & Factory
Automata Arts
Theatre at Ace Hotel
Los Angeles Theatre Center
The Bob Baker Marionette Theater
Bootleg Theater
2220 Beverly Blvd
Los Angeles, CA, 90057


text:
Bill Bowerbird is now available on Indigo and Amazon! Wickety-tickety-woo-hoo-hoo! You can also visit the Bill Bowerbird website here!
Bill is an eccentric collector, a borrower, a re-user, and recycler. He is a tinkerer, a mechanic, an engineer, and musician. He is a little Vaudeville, a little MacGyver, a little Fred Astaire, a little Dr. John.
Bill is not just your average type of bird. Bill is a bowerbird. And like any good bowerbird, Bill loves to collect interesting objects and build elaborate nests. Bill also has a great gang of friends, likes to throw parties, and loves going to bed. But Bill has one problem! He's got a terrible, unbearable beak-ache! What to do, what to do? Wickety-tickety-BOO-hoo-hoo!
He has a great gang of friends, like Gary the Grouse, Dr. Hoot (the owl), Wade the Walrus, Yolanda the Yak, the rope-skipping beavers Evie and Stevie, and the zebras Zee and Za. Empathy, community and sharing are very important in Bill's world. Bill also loves to have fun! He loves parties AND he loves going to bed!
Bowerbirds are native to New Guinea and Australia. To attract their mates, the males (whom are very boring in plumage), build elaborate, colour-sorted nests from sticks and interesting found objects (often garbage).
[Image credits TBA]


text:
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Week 1 Zero Waste
Friday, March 08, 2013
Here's the summary of my 'zero waste march' goal. It's not really zero, but I'm finding making a conscious effort to reduce waste to be eye opening.
What we consumed:
- 1lb of brussel sprouts
- 3 heads of romaine lettuce
- 1lb tomatoes
- 1/2 lb carrots
- 1/2 lb celery
- 6 mini cucumbers
- 3 large onions
- 1 head cabbage
- 1 lb steak
- 1 lb ground beef
- 1 whole chicken (5lbs)
- 1 lb pork butt
- 1/2 dozen eggs
- 1/2 lb red potatoes
Taking inventory of my fridge, it looks like I'm buying too many vegetables.
Here's what we have left:
1/2 lb tomatoes
6 mini cukes
2 lbs snap peas
1 lb brussel sprouts
6 whole onions
1/2 lb carrots
1/2 lb celery
I don't have a cellar, unfortunately, so the onions will only be good for another week. The remaining cucumbers were turned into pickles. The remaining sprouts will get eaten this weekend most likely.
The immediate concern is I have to do something with the snap peas fast. They have a fairly high sugar content, and won't last much longer. I'll either have to blanch them for freezing, or pickle them. I might do a combo of both.
I'm pleased that we didn't throw away any meat this week. No, wait. There was one little chicken wing that got pushed to the back of the fridge and sat too long. I thought I had this in the bag, so I was mortified when I found it this morning. Darn you, chicken wing.
We had excess meat we purchased, but we sealed and froze what we didn't use.
What we threw out:
- 1 rotten onion (bruised during shipping)
- 1 chicken wing
We also threw out some refuse from removing cabbage or lettuce leaves, but that was expected. I'll feel better about it once we get a composter. Hubs and I are in a slight disagreement over it. He's concerned about bugs and decay, and wants an enclosed system; I want something more open and natural. My main objection to the enclosed system is they are ugly. I don't want a garbage can in my garden. So we're still working on the details. If we had a composter, I would have happily thrown my rotten onion in there, knowing it would be recycled in my garden rather than dying in a landfill over mounds of plastic Coke bottles and Huggies diapers.
Oh there's no guilt like treehugger guilt.
This weekend I'll be busy making plans for the excess veggies. Now that I have a rough inventory of what we use versus what we buy, I'll scale down slightly what we buy for next week.
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I'm not much of a treehugger, but I hate wasting money! Thanks for inspiring me to be more careful about food waste.
1718 days ago
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1721 days ago
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1721 days ago
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Great goals! I love my composter. Even more, I love the lovely compost that I get as a result.
1721 days ago
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Well done!
1721 days ago
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My SparkPage
That is a thorough assessement! And a lot of veggies...
Maybe you could hide the composter behind a decorative fence or lattice?
1721 days ago
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My SparkPage
Don't forget about vermi-composting! Worms are such little work horses!! You get the castings for your garden and my vermicomposting pile has never smelled.
I take extra veggies, boil in a few cups of water and then blend with a hand blender adding a little salt and spices to taste. I then use it as a sauce on pasta or add broth and some protein and make soup. In the past, I have used onions, carrots, broccoli, cauliflower, beans, peas, mushrooms, garlic and celery. Never snap peas. It freezes well.
Consider making gaspacho with the cukes and tomatoes.
1721 days ago
Comment edited on: 3/8/2013 7:11:17 PM
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It does sound like you are doing pretty well with your plan.
1721 days ago
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What a great plan!!!
1721 days ago
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text:
A spin off forum of Rise of the Demigods
A refugee camp for all the naysayers, disagreers and disgruntled hooligans who were left stranded and without shelter when the TS4 Receptacle closed.
receptacle, refugees, refugee, #camp, naysayers, disagreers, disgruntled, hooligans, left, stranded, shelter, closed
A place for Percy Jackson and the Olympians fans to roleplay.
percy, jackson, demigod, #camp, half, blood, forumotion, olympus, forum, fanfiction, site
An RPG site that is based off of Rick Riordan's Percy Jackson series! Come join Camp Half-Blood and RP, chat, and meet new campers! Have fun and watch out for monsters!
free, forum, rise, demigods, site, rick, riordan's, percy, jackson, series, #camp, half, blood, half-blood, halfblood, role, play, roleplaying
Mystery lurks within the camp of our clan, enter with caution.
super secret sci-cave refugee camp
Forest River Wildcat Camper forum, A place for Wildcat camper owners to meet and share all their camping knowledge and meet new friends. Thats Scottz Rig
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text:
The previous agricultural policy document was finalized in 1988 and was supposed to remain operative until the year 2000. Hence, in year 2001, a new policy document was launched. The new policy document bears most of the features of the old one, but with more focused direction and better articulation.
Objectives of New Agricultural Policy
In a broad sense, the objectives of the new agricultural policy are very similar to those of the old one. They include:
(i) The achievement of self-sufficiency in basic food supply and the attainment of food security;
(ii) Increased production of agricultural raw materials for industries;
(iii) Increased production and processing of export crops, using improved production and processing technologies;
(iv) Generating gainful employment;
(v) Rational utilization of agricultural resources, improved protection of agricultural land resources from drought, desert encroachment, soil erosion and flood, and the general preservation of the environment for the sustainability of agricultural production;
(vi) Promotion of the increased application of modern technology to agricultural production; and,
(vii) Improvement in the quality of life of rural dwellers.
Key Features of the Policy
The key features of the new policy are as follows:
Evolution of strategies that will ensure self-sufficiency and improvement in the level of technical and economic efficiency in food production. This is to be achieved through:
(i) The introduction and adoption of improved seeds and seed stock,
(ii) adoption of improved husbandry and appropriate machinery and equipment,
(iii) Efficient utilization of resources,
(iv) Encouragement of ecological specialization, and
(v) Recognition of the roles and potentials of small -scale farmers as the
Major producers of food in the country.
Reduction of risks and uncertainties in agriculture, to be achieved through the introduction of a more comprehensive agricultural insurance scheme to reduce the natural hazard factor militating against agricultural production and security of investment.
A nationwide, unified and all-inclusive extension delivery system under the Agricultural Development Programs (ADPs).
Active promotion of agro-allied industry to strengthen the linkage effect of agriculture on the economy.
Provision of such facilities and incentives as rural infrastructure, rural banking, primary health care, cottage industries etc, to encourage agricultural and rural development and attract youths (including school leavers) to go back to the land.
Major Content of the Policy Framework
The policies cover issues on:
(i) Agricultural resources (land, labor, capital, seeds, fertilizer, etc) whose supply and prices affect the profitability of agricultural business,
(ii) Crops, livestock, fisheries and agro-forestry production,
(iii) Pest control,
(iv) Mechanization,
(v) Water resources and irrigation,
(vi) Rural infrastructure,
(Vii) Agricultural extension and technology transfer,
(viii) Research and development (R&D),
(ix) Agricultural commodity storage, processing and marketing,
(x) Credit supply,
(xi) Insurance,
(xii) Agricultural cooperatives,
(xiii) Training and manpower development, and
(xiv) Agricultural statistics and information management.
The successful implementation of the agricultural policy is, however, contingent upon the existence of appropriate macroeconomic policies that provide the enabling environment for agriculture to grow in equilibrium with other sectors. They affect profitability of agricultural enterprises and the welfare of farmers through their effects on the flow of credit and investment funds, taxes, tariffs, subsidies, budgetary allocation, etc.
The New Policy Direction
According to the document, the new agricultural policy will herald in a new policy direction via new policy strategies that will lay the foundation for sustained improvement in agricultural productivity and output. The new strategies involve:
(i) Creating a more conducive macro-environment to stimulate greater private sector investment in agriculture;
(ii) Rationalizing the roles of the tiers of government and the private sector in their promotional and supportive efforts to stimulate agricultural growth;
(iii) Reorganizing the institutional framework for government intervention in the agricultural sector to facilitate the smooth and integrated development of the sector;
(iv) Articulating and implementing integrated rural development programs to raise the quality of life of the rural people;
(v) Increasing budgetary allocation and other fiscal incentives to agriculture and promoting the necessary developmental, supportive and service-oriented activities to enhance agricultural productivity, production and market opportunities; and
(vi). Rectifying import tariff anomalies in respect of agricultural products and promoting the increased use of agricultural machinery and inputs through favourable tariff policy.
Key Agricultural Development, Supportive and Service Delivery Programs of the Federal Government
Following the redefined roles and responsibilities of tiers of government and the private sector, the main thrust of federal government programs and activities will be directed at obviating the technical and structural problems of agriculture in the following respects.
Development Programs and Activities
These will include research and development, (including biotechnology development), animal vaccine production, veterinary drug manufacture, agro -chemicals manufacture, water management, adaptive technology promotion, and the creation and operation of an Agricultural Development Fund.
(a) Research and development, including biotechnology: The effort in this direction is to finance agricultural research, including biotechnology and the breeding of predators for the biological control of crop pests which the private sector may not be willing to invest in due to the high capital outlay and a relatively low return from agricultural investments. The output of the research system will be disseminated by the extension services of the states and local governments to farmers, ranging from small-scale to large-scale farmers.
(b) Animal vaccine production:The capacity of the National Veterinary Research Institute (NVRI), which is the premier institution for animal vaccine production in the West Africa sub-region, will be strengthened, enlarged and modernized in order to raise the level of vaccine production in Nigeria to a self-sufficiency level and also to cater for the entire West Africa sub-region.
(c) Veterinary drug manufacture:A veterinary drug manufacturing outfit with the capacity to meet the needs of the West Africa sub-region will be established. Relevant agencies of government will collaborate with the private sector for the accelerated take off of the factory. Government interests in this venture will, however, be sold to the private sector in line with the privatization policy.
(d) Agro -chemicals manufacture: Government will manufacture and promote the production of agro-chemicals by the private sector and will ensure the protection of the users, the eco-system and the environment through appropriate pesticide legislation. Effective monitoring mechanism to ensure compliance with the law will be put in place.
(e) Water management: Currently, large dams constructed in the country have impounded a lot of water with high fisheries and duck farming potentials and having the capacity for irrigation. The completion of the outstanding downstream irrigation infrastructure of the already completed large dams in the country will be accorded top priority in order to make them useful to the farmers and to maximize the benefits of the huge investments already incurred in constructing them.
Emphasis will now shift to developing small dams as a more cost effective way of utilizing water resources for irrigation in the country. The maintenance of the existing large dams will, however, continue to be the responsibility of the Federal Government. In addition, rain harvesting for irrigation agriculture is to be promoted where surface and underground water is not readily available.
(f) Adaptive technology: Economic deregulation has increased agricultural production costs astronomically. At the same time, globalization of trade, which thrives on comparative advantage in production, makes efficiency of production and the application of economies of scale mandatory if Nigeria is to get a sizeable market share in the highly competitive global trade arena. In order to improve efficiency of production, therefore, simple labor -and cost-saving devices that are appropriate for the current level of agricultural production and processing in the country will be developed and mass-produced. The National Centre for Agricultural Mechanization (NCAM), the institution established for this purpose, will be strengthened. Other initiatives in this direction, such as animal traction and hand tools technology development, will be encouraged.
(g) Agricultural Development Fund: The National Agricultural Development Fund is to provide the necessary impetus for the sustainable development of the agricultural sector. It will support both public and private sectors in carrying out activities that will boost agricultural and rural development, with emphasis on all facets of agricultural research, market development, extension delivery, long-term credit, rural Institutions development and enterprise promotion. The Fund will derive its revenues from:
(i) Savings from subsidy withdrawals on fertilizer,
(ii) 5 percent of the proceeds from the privatization of government enterprises,
(iii) funds from international commodity organizations.
(iv) 2 percent levy on the profits of agro-based industries,
(v) 50 percent of Sugar Development Levy,
(vi) 1.0 percent levy on the profits of oil companies,
(vii) Appropriation from government annual budget of not less than 2 percent of the total budget, and
(viii) take-off grant from the federal government.
Supportive Activities
These will comprise input incentive support and commodity marketing and export activities.
a) Input incentive support: Government incentive support for inputs will be administered in a cost-effective and focused manner to ensure that the intended beneficiaries derive full benefit from the distribution of:
(i) seeds, seedlings, fingerlings, brood stock etc,
(ii) fertilizers,
(iii) agro-chemicals,
(IV) tractors and implements,
(v) vaccines
(VI) veterinary drugs, and
(vii) agricultural credit. State and local governments are also to be encouraged to subsidize these inputs, as an additional incentive for agriculture.
b) Commodity marketing and export: The development of an efficient agricultural marketing system is being promoted through the provision of adequate market information. The buyer of last resort mechanism built into the marketing system will provide price stabilization effect on the system. The three multi-commodity marketing companies already approved by government will be the fulcrum of this system. The companies which will be private sector-led and managed, but with initial substantial public sector participation, will also ensure quality management and export promotion, in conformity with international quality standards for Nigeria's agricultural commodities.
Service Delivery Activities
These activities will cover input supply and distribution, agricultural extension, micro-credit delivery, cooperatives and farmer/commodity associations, commodity processing and storage, agro-allied industry and rural enterprise development, and export promotion of agricultural and agro-industrial products.
(a) Input supply and distribution: Government is creating the more conducive environment for profitable investments in the production and distribution of inputs such as improved starter materials, animal health drugs, fertilizers, etc. Fertilizer supply will be hinged on complete privatization and liberalization in the production, distribution and marketing of the commodity. The main role of the government will be to strictly monitor the quality standard of all fertilizers (both local and foreign) to ensure that only certified products reach the farmer. Government will also encourage the use of organic fertilizers to complement the inorganic fertilizers currently in use. The seed industry development program will be reinvigorated and community seed development programs will be promoted to ensure the provision of adequate and good quality seeds to local farmers. The organized private sector will be mobilized, encouraged and given incentives to actively participate in the production of seeds, seedlings, bloodstock, fingerlings, etc, and also to be involved in out-growers mobilization.
(b) Agricultural extension: Agricultural extension is essentially an activity that should be carried out by the lower tiers of government. But given the overriding importance of technology dissemination, all the three tiers of government in Nigeria will be involved in jointly financing agricultural extension delivery and monitoring its impact. Also, extension service delivery will be streamlined through the integration of ADP and state extension services for greater effectiveness.
(c) Credit and micro-credit delivery: The strategies to be adopted will include:
(i) provision and improvement of rural infrastructure to attract investment & financial services;
(ii) integration and linkage of rural financial institutions to the formal banking sector;
(iii) regulating and supervising the growth of non-bank financial institutions with emphasis on savings mobilization at the grassroots;
(iv) expanding the mandate of the restructured Nigerian Agricultural Cooperative and Rural Development Bank (NACRDB) to include savings mobilization;
(v) supporting self-help groups in their savings mobilization and credit delivery activities;
(vi) modification of the credit delivery system to include the cooperative and community-based organizations as delivery channels to reduce transaction costs; and,
(vii) modification of terms of credit such as interest rate, eligibility criteria, legal requirement, etc, to enhance access.
(d) Cooperatives and farmer/commodity associations: Resource mobilization and the promotion of group action are the thrust of cooperative activities. This is to take advantage of group dynamics, with its concomitant mutual guarantee, as a strategy for agricultural development. Services which cooperatives can render include the administration of government incentives to agriculture, such as inputs supply, credit delivery and retrieval, commodity marketing, and the pursuit of democratic ideals, in view of the democratic principles embedded in their operations.
(e) Processing, storage, agro-allied industry and rural enterprise development: The use of simple but effective on-farm and off-farm storage facilities and agro-processing technology will be promoted to add value to products and increase their shelf life. The Strategic Grain Reserve Scheme will be modernized, strengthened and upgraded to a National Food Reserve Program, which will enable it to handle all staples and essential food products. This will be the launch pad for the accelerated attainment of Nigeria's national food security goal. The Buffer Sock Food Storage Scheme of the states will incorporate the use of private storage facilities to maintain a national strategic stock of food that will be needed in times of national food emergencies. It is also crucial to promote and develop agro-processing in the country for the evolution of virile agro-allied industries and rural micro-enterprises.
(f) Export promotion of agricultural and agro-industrial products: Nigeria has comparative advantage in the production of a number of exportable agricultural commodities, such as cocoa, palm produce, rubber, ginger, spices, fruits and vegetables, flowers, shrimps and ornamental fish, cassava products, hides and skin, cashew, gum arabic, groundnuts and cotton (products). In order to diversity the base of the Nigerian economy and widen the market for agricultural commodities to absorb the expected increase in production, there is need to promote the export of these agricultural and agro-industrial products. To facilitate the acceptance of Nigerian agricultural commodities in the international market, including taking full advantage of the US African Growth and Opportunity Act (AGOA), there will be need to develop appropriate capacities and institutional framework within the agricultural sector as well as in other relevant sectors to meet the Sanitary and Phytosanitary Standards (SPS) and comply with the Technical Barriers to Trade (TBT) agreements of the World Trade Organization (WTO).
Other Policies, Institutions and Legal Framework
The range of macroeconomic and institutional policies as well as legal framework that affect agricultural investment in particular and agricultural performance in general is wide. The policies broadly cover fiscal, monetary and trade measures. There is also a large body of institutional policies that support not only the implementation of macroeconomic policies but also that of agricultural sector policies. Then, there is a set of national and international legal framework, including bilateral and multilateral agreements and treaties that provide the enabling environment for foreign and domestic private investment, promote international trade and, therefore, promote economic growth.
Environmental concern has increasingly come into focus in the design of policies for sustainable growth and development in Nigeria, as elsewhere in the world. Hence, Nigeria has now put together a set of environmental policies and strategies that are of important relevance to agriculture.
Macroeconomic Policies
The key components of macroeconomic policies are fiscal, monetary and trade policies.
Fiscal Policies: These focus on budgetary, tax and debt management policy instruments. Budgetary policy influences economic stability and rate of inflation in the economy. These, in turn, influence the climate for the flow of investment, especially foreign private investment. Tax policies that focus on personal and corporate tax rates, tax reliefs, and other tax concessions are key incentives (or disincentives) factors affecting consumption and investment decisions. A favorable corporate tax policy regime enhances after-tax profits and, to that extent, may promote increased investment. A country's external debt burden affects its international credit rating and its capacity to finance public investment. International credit rating affects the flow of foreign private investment while the level and quality of public investment directly affect the flow of both foreign and domestic private investment.
Monetary Policies:
In general, monetary policies refer to the combination of measures designed to regulate the value, supply and cost of money in the economy, in consonance with the expected level of economic activity. Liquidity, interest rates and foreign exchange rates are the channels through which monetary policy influences economic activities. Liquidity is affected by money supply. Money supply influences credit supply and interest rate (cost of capital). Interest rate, in turn, influences consumption, savings and investment decisions in the economy. Basically, the existence of interest and exchange rate differentials, resulting from monetary policy measures, induces substitution between domestic and foreign assets (foreign currencies, bonds, securities real estate, etc) as well as domestic and foreign goods and services (CBN, 1997). Since 1986, the main instruments of market-based monetary policies have included the open market operations (OMO), changes in reserve requirements and discount policy. Open market operations involve the discretionary power of the CBN to purchase or sell securities in the financial markets in order to influence the volume of liquidity and levels of interest rates that ultimately affect money supply.
The sale of financial instruments by the CBN restricts the capacity of banks to extend credit, thereby affecting inflation and interest rates. The reverse is the case when financial instruments are purchased.
Trade Policies:
These are a very important component of structural adjustment policies. The main focus of trade policies is on measures to regulate export and import trade through such measures as tariffs, export and import quotas and prohibitions. They influence the investment climate in many ways. For example, a liberal trade policy constitutes an incentive for foreign investors who may need to import raw materials and / or export products. But a protectionist trade policy may also serve as an incentive for investors in non-tradable products that are largely locally consumed, or investors in import -substitute products.
Institutions: According to the World Development Report (2002), institutions are rules, enforcement mechanisms and organizations put in place in an economy. Distinct from policies that are the goals and the desired results, institutions are rules, including behavioral norms, by which agents interact, and the organizations that implement these rules and codes of conduct to achieve desired outcomes. Policies influence the types of institutions that evolve while institutions too affect the types of policies that are adopted. Appendix 4.1 presents some of the major institutions that affect or are affected by investment -related policies in Nigeria.
Investment Legal Framework: Investment legal framework provides incentives for, regulates or protects investments, especially foreign investment. According to Aremu (1997), a foreign investor is first concerned with some basic questions like: What areas of business are open to foreign participation? How easy is it to bring capital into the country and repatriate profits and capital from the country? What legal mechanisms exist to protect the investor's personal business interest? These questions underscore the importance of investment legal framework. Some of the important domestic investment legislations and international legal arrangements governing foreign private investment are as contained in the NIPC Act 16 of 1997
Environmental Policies: Environmental policies are very important for sustainable growth and development. Hence, the Federal Environmental Protection Agency (FEPA) produced a revised version of the national policy on the environment in 1999.
The goals of National Policy on the Environmental is to achieve sustainable development in Nigeria, and, in particular, to:
(i) secure a quality of environment adequate for good health and well being;
(ii) conserve and use the environment and natural resources for the benefit of present and future generations;
(iii) restore, maintain and enhance the ecosystems and ecological processes essential for the functioning of the biosphere to preserve biological diversity and the principle of optimum sustainable yield in the use of living natural resources and ecosystems;
(iv) raise public awareness and promote understanding of the essential linkages between the environment, resources and development, and encourage individual and community participation in environmental improvement efforts; and
(v) Co-operate in good faith with other countries, international organisations and agencies to achieve optimal use of transboundary natural resources and for an effective prevention or abatement of transboundary environmental degradation.
The strategies to be adopted include:
(i) addressing the issues of population growth and resources consumption in an integrated way;
(iii) setting goals for the stabilization of national population at a sustainable level;
(iii) integrating resource consumption and demographic goals with the other sectors and economic objectives;
(iv) monitoring trends in population and resource consumption and assessing their implications for sustainability;
(v) encouraging and involving the private sectors, NGOs and the public in the implementation of strategies and actions aimed at achieving stated goals;
(vi) the prevention and management of natural disasters such as flood, drought and desertification that more directly impact on the lives of the populace;
(vii) integration of population and environmental factors in national development planning;
(vii) solving public health problems associated with rapid urbanisation and squalid urban environments;
(ix) prevention of the depletion of forests through judicious search for and adoption of alternative energy sources; and
(x) Control of the demands and patterns of land resources usage.
Food Production/Processing
- Cassava Production & Processing (10% cassava flour mandatory in all baked foods)
- Cocoa Production & Processing (Presidential initiative to encourage production & local processing of cocoa, integrated into UBE program of government.
Export Crops
Raw Materials
Poultry,Livestocks, Fisheries
Research Developmeent
Seeds Production
Animal Husbandry
Agricultural Entension Services
Agricultural Engineering & Irrigation Activities
Animal vaccine production
Agro -chemicals manufacture
Agriculture is now an exciting sector. Today major local and international investors are investing in this new agriculture sector, with $5.6 billion in investments. The number of seed companies alone has risen from 5 to 80 within three years.
Presently, the agricultural sector grew by 9.19% (year-on-year) in Q 3 of 2014, up by 2.7% points from Q3 of 2013. The agricultural sector grew by 38.53% between 3rd and 4th quarters of 2014, with crop production being the main driver, with a growth of 43.5% .
$5 Billion worth of investments in fertilizer manufacturing currently ongoing by Dangote Group, Indorama, Notore Chemicals, and others.
Olam has invested $70 million in mechanized rice farm.
Dangote to Invest $1 Billion for large scale rice production
Teragro (a subsidiary of Transcorp Group) has established a $6 million plant to process oranges into concentrates.
At the moment, agricultural sector contributes 47 per cent to the country's Gross Domestic Product (GDP) and is responsible for 10 per cent of its export earnings.
Foreign direct investment inflows are currently at $6.1 billion and the GDP is growing at a rate of 7.71 per cent, making Nigeria the fastest growing economy in Sub-Saharan Africa.
General IncentivesPioneer status
Tax Relief for Research & Development
Minimum Local Raw Materials Utilization – Tax credit of 20% for 5yrs to industries that attained minimum levels of local materials sourcing & utilization (70% for agro allied)
Agricultural Machinery & Equipment attracts zero % duty (effective Jan 2012).
Corporate tax incentives rebate of 12% shall be enjoyed by Bakers on attainment of 40% cassava blend within a period of 18 months. (eff. March 2012.
Companies in the agro-allied business do not have their capital allowance restricted. It is granted in full i.e. 100%.
Agro-allied plant and equipment enjoy enhanced capital allowances of up to 50%.
The payments of minimum tax by companies that make small or no profits at all do not apply to agro-allied business.
Agricultural Credit Guarantee Scheme Fund (ACGSF) administered by the Central Bank of Nigeria: Up to 75% guarantee for all loans granted by commercial banks for agricultural production and processing.
Interest Drawback Program Fund:
60% repayment of interest paid by those who borrow from banks under the ACGS, for the purpose of cassava production and processing provided such borrowers repay their loans on schedule.
The Federal government has introduced various funding mechanism that will stimulate investments into the sector. The Nigerian Incentive-based Risk Sharing System for Agricultural Lending (NIRSAL) of the Central Bank of Nigeria (CBN) has reduced the risk in banks' lending for farmers and reduced the lending rate to farmers. . Banks are lending to agriculture today more than ever before. The share of lending to agriculture as a share of total bank lending expanded from about 2 per cent in 2011 to 5 per cent by 2013 and 9% in 2014.
Bank lending to seed companies and agro-input dealers expanded from $10 million in 2012 to $53 million in 2013 while bank lending to fertilizer companies expanded from $100 million in 2012 to $500 million by 2014."
Others includes:
N787 World Bank intervention funds to farmers
N50b mechanization support fund for agricultural equipments hiring enterprises;
₦14 billion for the expansion of 2014 dry season farming.;
N10 billion rice processing fund
N500 fund for cotton farmers etc.
Over the past three decades, Nigerian government had initiated a plethora of policies and programmes which were aimed at restoring agricultural sector to its pride of place in the economy. However various efforts at promoting investment and export diversification in the agricultural sector have not yielded appreciable dividend.
Enormous investment and export diversification potentials for generating higher growth in the economy have remained unlocked and unexploited in the agriculture due to a host of constraining factors that must be removed.
• Government should invest heavily in rural infrastructure development that will promote private investment in all areas of agriculture and facilitate linkage of agriculture to industry. The rural electrification programme should be intensified to cover all rural villages in the country.
• Improvement in downstream Agricultural Commodity Activities: Primary activities encompassing crop planting and harvesting constitute upstream agricultural commodity activities from which primary commodities emerge. Following these are some essential secondary or post-harvest activities that constitute downstream activities. These secondary activities are important in adding value to the primary product,
improving its quality and rendering it less perishable. In general, downstream commodity activities improve the market opportunities for agricultural products and promote their commercialization, enhancing not only its competitiveness but also the rate of return on their investment. Key downstream commodity activities include: storage, processing into intermediate or final (finished) products, and marketing and distribution through domestic and export trade. Key intermediate supporting services for these downstream activities include adequate infrastructure (physical, economic, and social), efficient financial institutions, adequate human capital, relevant local organizations (such as community-based organizations, farmer organizations, etc.), transport services and commodity grading and quality control services.
• Improve agricultural production, processing and trade through increased access to resources such as land, technology (improved inputs) credit, training. Adoption of modern farming and husbandry practices such as planting of improved seeds and seedlings, application of agricultural chemicals for pest and disease control and tractors to reduce drudgery and enhance yields should be facilitated by assisting the farmers in sourcing improved technologies. Small-scale irrigation in all agro-ecological zones of the country should be promoted and strengthened.
• Government should sustain its drive to achieve a stable macroeconomic environment, which manifests largely in price stability. On the social front, government should ensure security of life and property to attract domestic and foreign investment to the sector.
• Increased support for Agricultural Research and Extension: There is the need to strengthen agricultural research activities through increased and stable funding, proper coordination, strengthening of linkages among research centres as well as adequate training of research and technical staff in specialized skills. Research systems must identify new mechanisms to find out why farmers do what they do, their research needs and priorities.
• Employment and income generation should be enhanced through promotion of diversification of rural economy. Government should support capacity building among small-scale farmers and facilitate linkages with large processors and manufacturers using agricultural commodities so as to develop long-term contractual arrangements among them. Also government should promote value-added agriculture to provide stimulus for wealth creation and employment creation.
• Increased funding of the agricultural sector so as to improve efficiency of institutional agencies for agricultural development. The functions of the agencies should be streamlined to ensure adequate funding for their core functions.
• Environmental Management: Increased investment in the agricultural sector and the resulting commercialization of products will most likely pose increased threat to environmental damage either through land degradation, pollution of the ecosystem by the effluent of processed agricultural commodities or the exhaustion of agricultural resources. Sustaining the agriculture environment will require adopting the following strategies: promotion of proper cultural practices associated with various commodities recommended by developers of improved technology packages. Adoption of post-harvest processing technologies that minimize waste and control pollution of the environment.Use of crop and livestock mix enterprises that prevent and minimize soil degradation.
In conclusion, the potentials for domestic and foreign investment in different agricultural enterprises in the different zones of Nigeria are high, in view of the large population size of the country, the availability of abundant resources and raw materials and the opportunity to earn good returns from investment. Efforts put into ensuring effective implementation of the above recommendations will constitute quick wins in stimulating the flow of investment into the agricultural sector. This will pave way for diversification of revenue sources, increased income, employment generation and poverty reduction in the country.


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By Sarah Rafique
Killeen Daily Herald
Michael Dewees knows a new pair of shoes and a jacket go a long way when it comes to making low-income children feel a little bit better about themselves. And a lot warmer.
"With shoes and jackets, a lot of us who are blessed take these things for granted," said Dewees, executive director for Communities in Schools Greater Central Texas Inc. "To these kids, and especially the parents of these kids, it's a big issue. Their self-esteem is lowered when they don't have the types of things that everyone else does."
Dewees said there is always a need for donations of jackets and coats during winter.
The nonprofit serves at-risk students across seven school districts, including Killeen, Copperas Cove, Temple, Belton, Salado, Florence and Cameron. It received about 100 jackets and coats from the Harker Heights Rotary Club last month. All the jackets were given to students who needed them, along with about 680 pairs of shoes.
"They consider us one of their partners and know we can get these out to children who really need them (because they) outgrow their old jackets or they're ripped to shreds," Dewees said.
The Killeen Independent School District has about 1,200 students identified as homeless, said Diana Miller, assistant superintendent.
"Several community organizations held coat drives for our students earlier this year," she said. "KISD is grateful for the support of our community partners."
Tina Capito, co-director of My Tutor and More, said her organization tries to help the Killeen Independent School District's Homeless Awareness Response Program throughout the year.
"We donated a ton of used jackets and delivered them right before Christmas break," Capito said. "Kid-sized clothes are harder to keep in stock. ... Last time I was (at HARP's clothing closet), the shelves didn't have as many long pants for grades one through five."
Dewees said providing warm clothing during winter helps the nonprofit with its mission of keeping at-risk children in school.
"To get a jacket or a new pair of shoes, it really lifts their spirits and helps in their self-esteem and then they improve in school," Dewees said.


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FIXR Multi-Tool With Leather Pouch
- Get this stainless steel multi-tool
- Get the job done with the FIXR Multi-tool
- Light and robust compact tool
- Contains numerous tools for various jobs
- Makes a great gift for DIY guy
More product info
Treat yourself of the handy man you know to this FIXR Multi-Tool. A useful little invention that's light enough to carry with you and easy to attach to your belt or keys! This multi-tool device features a numerous set of tools for those everydays jobs that need doing. Hidden neatly behind a gold plated revolving disc to keep the tools tucked away when not in use. No job is too big or small with this FIXR Multi-Tool Device.
Tools included
- Small Phillips Driver
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- Bicycle Spoke Spanner
- Bottle Opener
- Nail Cleaner
- Eyeglass Screwdriver
- Razor Sharp Cutter
- Wire Stripper
- File
- Measure
- Box Opener
- Carabiner Clip
- Pry Bar
- 5 Spanner Sizes
If you're looking for a gift a little different for the guy who likes to 'get the job done' then this FIXR Multi-Tool is a must have accessory.
- 10mm spanner/wrench
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- 6mm spanner/wrench
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- Bicycle spoke wrench
- Bottle opener
- Box opener
- File
- Large flat screwdriver
- Medium flat screwdriver
- Medium Phillips screwdriver
- Nail cleaner
- Pry bar
- Quick release clip
- Razor sharp cutting blade
- Ruler
- Small flat eyeglass screwdriver
- Small Phillips screwdrivers
- Wire stripper


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Amish "Montana Collection" Pine Log Coat Rack by Montana WoodworksDecorate your rustic motif with these practical authentic Amish log coat racks. Choose from 3 sizes. These rustic coat racks come with "D" ring style hooks on the back for hanging, or they can be drilled directly into studs.
This coat rack features pieces of Lodgepole pine which are hand-peeled with all of the outer bark as well as most of the inner cambium layer removed, which gives this collection a subtle rustic contrast.
Approx. dimensions:
3 Foot: 36"W x 8"D x 6"h, 5 lbs, 5 hooks
4 Foot: 48"W x 8"D x 6"h, 7 lbs, 6 hooks
5 Foot: 60"W x 8"D x 6"h, 10 lbs, 8 hooks
This character-rich piece of Amish furniture by Montana Woodworks is handmade in America from sustainably harvested, dead-standing Lodgepole Pine.
Each piece of this durable heirloom-quality rustic furniture is signed by the artist who makes it.
Shipping charges may apply if this item is ordered individually. This item generally ships within 7-10 business days. The manufacturer offers a 20-year materials and workmanship warranty on all of their rustic furniture.