6,890 research outputs found

    The effect of phase-feeding on the growth performance, carcass characteristics and nitrogen balance of growing and finishing pigs.

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    peer-reviewedA completely randomised design experiment was conducted to determine if grouphoused grower-finisher pigs (43.9 to 95 kg) show differences in performance and nitrogen utilisation when provided with a single high lysine diet (11 g/kg) or with a mean lysine concentration of 9.5 g/kg, either as a single diet or as a series of two or four diets. Four hundred and forty pigs were assigned to four dietary treatments. The experimental treatments were (total lysine) (1) 11 g lysine/kg from day 0 to slaughter (SHD) (2) 10.5 g/kg lysine from day 0 to day 28 and 8.5 g/kg lysine from day 29 to slaughter (DFD) (3) 9.5 g/kg lysine from day 0 to slaughter (RFD) and (4) 11 g/kg lysine from day 0 to day 14, 10 g/kg lysine from day 14 to day 28, 9.0 g/kg lysine from day 28 to day 42 and 8.0 g/kg lysine from day 42 to slaughter (PFD). The estimated lysine concentration required for treatments RFD, DFD and PFD was 9.5 g/kg for group-housed pigs. All diets were pelleted and formulated to have a net energy concentration of 9.8 MJ/kg. The pigs were group fed in mixed-sex pens using single space feeders (11 pigs/feeder, 6 boars and 5 gilts). Daily feed intake was lower (P < 0.05) in treatment SHD in comparison to RFD and DFD during the overall grower-finisher period (2.08 vs 2.18 and 2.23 kg/day, respectively). Lysine conversion ratio was poorer for pigs on treatment SHD compared with DFD (P < 0.01), RFD (P < 0.01) or PFD (P < 0.001), while food conversion ratio was better for pigs on treatment SHD compared with treatments DFD (P < 0.01) and PFD (P < 0.001) during the grower-finisher period (2.31 vs 2.43 and 2.48 kg/kg, respectively). N intake and excretion were higher (P < 0.001) for pigs offered SHD compared to all other treatments (3.93 vs 3.51, 3.42, 3.40 kg and 2.56 vs 2.14, 2.03, 2.10 kg for SHD vs DFD RFD and PFD for intake and excretion, respectively). N utilisation coefficient was lower for pigs on treatment SHD than pigs on treatments DFD (P < 0.01), RFD (P < 0.001) or PFD (P < 0.01). In conclusion, phase feeding did not result in any benefit to pig performance, N excretion, N utilisation or carcass characteristics when compared with a single diet that was formulated to match the animal’s requirement for lysine (treatment RFD)

    Effect of pixel dimensions on SAR picture quality

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    In an SAR mapping system, the product of looks per pixel and number of pixels in the scene is kept constant. Assuming that the returns from all resolution cells obey Rayleigh statistics, the expression for pixel SNR incorporating both speckle and additive white Gaussian noise was derived. It is shown that it is possible to use fine resolution and leave the large-area estimate slightly but not much worse than if a larger pixel size had been initially decided upon

    Comparison Between Genetic and Morphological Sex of the Cranium

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    Morphological methods are relied upon to determine the sex of skeletal remains of both archaeological and forensic significance. The characteristics commonly examined in these morphological methods have a large margin of error, especially when it comes to partial or fragmentary cranial remains. The case could be made from this morphological study that sex attributed to fragmented remains where not more than one commonly scored trait is available for examination should not be considered as being fully reliable. In this study, I examined 20 crania from a collection from Tepe Hissar to compare morphological sex and genetic sex. Overall, the mastoid process should be considered a better indicator of sex than the supraorbital margins, nuchal crest, supraorbital ridges, and mental eminence. It is safe to assume that if the genetic sex and the morphological sex are the same, that sex is definitive. Conversely, it is difficult to determine which is correct when the morphological sex does not align with the DNA-determined sex. Through this research I have concluded that DNA analysis and morphological methods have the most significant advantages, especially over their alternatives, analysis of tooth size and wear and measurements plugged into discriminant functions, but have significant drawbacks

    Carbon, Cookstoves, and Kitchens: Case Studies of Fuelwood Use and the Potential for Ethanol Substitutability in Rural India, Vietnam, and Tanzania

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    Fuelwood constitutes the primary domestic cooking fuel in many rural communities throughout the Global South. Unsustainable levels of fuelwood consumption, however, contribute not only to local forest degradation but also to global climate change through the release of black carbon and carbon dioxide into the atmosphere. Moreover, as a driver of indoor air pollution, it also negatively affects human health. Indoor air pollution linked to cooking smoke is among the leading causes of preventable respiratory disease, and negatively impacts women and children through disproportionate and repeated exposure. While many cleaner and more efficient alternate stove designs have been developed for use in fuelwood-dependent communities, culturally-based user incompatibilities and technical design problems can lead to lack of widespread adoption. Although fuelwood dependence has also been offset by the availability of subsidized commercially-available fuels such as kerosene or liquid petroleum gas (LPG), the need persists for a clean, efficient, locally available, and sustainable fuel source for use in household cooking. This poster presents the results of three related, pilot project case studies about the potential for alcohol-fueled stoves to serve as a pathway to fuelwood substitution. The poster explores questions of cultural feasibility and the related roles of gender/class/ethnicity dynamics within a community, cooking and fuel preferences of stove users, and religious considerations related to non-consumptive alcohol use. Our study raises important issues for advocates of alternative technologies to consider, including the potential for resource capture by elites, openings for promotion of gender equity, and opportunities for socially and environmentally sustainable development

    Synthesis of Recursive ADT Transformations from Reusable Templates

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    Recent work has proposed a promising approach to improving scalability of program synthesis by allowing the user to supply a syntactic template that constrains the space of potential programs. Unfortunately, creating templates often requires nontrivial effort from the user, which impedes the usability of the synthesizer. We present a solution to this problem in the context of recursive transformations on algebraic data-types. Our approach relies on polymorphic synthesis constructs: a small but powerful extension to the language of syntactic templates, which makes it possible to define a program space in a concise and highly reusable manner, while at the same time retains the scalability benefits of conventional templates. This approach enables end-users to reuse predefined templates from a library for a wide variety of problems with little effort. The paper also describes a novel optimization that further improves the performance and scalability of the system. We evaluated the approach on a set of benchmarks that most notably includes desugaring functions for lambda calculus, which force the synthesizer to discover Church encodings for pairs and boolean operations
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