Characterization of village chicken production performance under scavenging system in Halaba district of southern Ethiopia

Village chicken production was characterized using retrospective and crosssectional methods, where 280 households rearing local chickens in Halaba district of southern Ethiopia were used for data collection. The study revealed that the average flock size was 8.5 chickens (95% CI=7.98 – 9.08). The average number of chickens added to a flock annually was 28.3 birds (95% CI=27.76 – 28.86) while 22.9 birds (95% CI=22.36 – 23.53) were leaving the flock. The majority of the households (77.7%) constructed a wooden perch for night resting of their chickens inside the main house. Scavenging was the major avenue of feeding chickens. Most of the respondents (83.6%) practiced selection in their chicken flocks for females (68.4%) and both sexes (31.6%). The average number of eggs laid by local hen was 13.3 eggs/hen/clutch (95% CI=12.81 – 13.85) and the mean annual egg production was 50.8 eggs per year with an average clutching frequency of 3.8 clutches (95% CI = 3.69 – 3.92). The average clutch length was 26 days (95% CI = 24.92 – 27.08). While the age at first lay of village chickens was 6.53 months (95% CI = 6.45 – 6.61), the average weight at first lay was 0.91 kg (95% CI = 0.87 – 0.96). The mean egg weight for the village chickens was 39.4 g (95% CI = 38.79 – 39.91). The average hatchability of eggs in this study was 83.7 % (95% CI = 81.73 – 85.72). The survival rate of chicks to 6 months of age was 52.3% (95% CI = 51.09 - 53.45). It was concluded that village chicken production was characterized by low input and output system, and scavenging was the dominant form of feeding of village chicken.Key words: Village chicken – Scavenging – Productivity – Clutc

Large Deviations Behavior of the Logarithmic Error Probability of Random Codes

This work studies the deviations of the error exponent of the constant composition code ensemble around its expectation, known as the error exponent of the typical random code (TRC). In particular, it is shown that the probability of randomly drawing a codebook whose error exponent is smaller than the TRC exponent is exponentially small; upper and lower bounds for this exponent are given, which coincide in some cases. In addition, the probability of randomly drawing a codebook whose error exponent is larger than the TRC exponent is shown to be double–exponentially small; upper and lower bounds to the double–exponential exponent are given. The results suggest that codebooks whose error exponent is larger than the error exponent of the TRC are extremely rare. The key ingredient in the proofs is a new large deviations result of type class enumerators with dependent variables

Scotland, Catalonia and the “right” to self-determination: a comment suggested by Kathryn Crameri’s “Do Catalans Have the Right to Decide?

No abstract available

Knowledge, Representation, and the Physical World

This dissertation answers how mathematical representations enable knowledge of physical systems. Contemporary responses rely on matching the properties of physical systems to properties in mathematical models, arguing that such matching allows scientists to successfully draw conclusions about physical systems through the inspection of their models. We argue that such “matching accounts” cannot adapt to the routine mismatching pervasive in physical theories. These mismatching problems arise both when idealized models match some “similar” but better behaved potential physical system, and in cases we classify as pathological idealization, where the models employed must satisfy constraints that could not possibly be matched by realistic physical systems (e.g. requiring an infinite particle number or infinite density). In the latter cases such pathological constraints can also lead to incompatibilities with the governing laws of the physical theory. Despite such pathologies, conclusions drawn with these representations seem to enable improved understanding and empirically confirmable knowledge of the studied physical systems. To address this dichotomy, we develop a novel condition of successful mathematical representation, called epsilon-fidelity, under which mismatched models may facilitate knowledge of realistic physical systems. Arguing against direct matching, we propose that representations can meet the conditions of epsilon-fidelity by establishing a manifold of associations between topological neighborhoods of mathematical models and clusters of relevantly similar physical systems. We then demonstrate that this shift in the scope of representation relationships explains how suitably similar models entail conclusions about the relevant systems while avoiding the problems of individual model to system mismatching. As a signature case study, we investigate Einstein’s canonical interpretation of the geodesic principle, originally proposed to govern how gravitating bodies travel according to general relativity theory. We argue that under the canonical interpretation models of bodies must either meet unrealistic assumptions or violate the theory’s fundamental field equations, marking them as pathological idealizations. To recover the principle, we reinterpret geodesic dynamics as a universality thesis about the collective behavior of certain classes of systems, explaining how this reinterpretation satisfies the epsilon-fidelity criteria and can be used to gain knowledge about the observable motion of actual classes of gravitating bodies

Continuous atom laser with Bose-Einstein condensates involving three-body interactions

We demonstrate, through numerical simulations, the emission of a coherent continuous matter wave of constant amplitude from a Bose-Einstein Condensate in a shallow optical dipole trap. The process is achieved by spatial control of the variations of the scattering length along the trapping axis, including elastic three body interactions due to dipole interactions. In our approach, the outcoupling mechanism are atomic interactions and thus, the trap remains unaltered. We calculate analytically the parameters for the experimental implementation of this CW atom laser.Comment: 11 pages, 4 figure

A Survey on Approximation Mechanism Design without Money for Facility Games

In a facility game one or more facilities are placed in a metric space to serve a set of selfish agents whose addresses are their private information. In a classical facility game, each agent wants to be as close to a facility as possible, and the cost of an agent can be defined as the distance between her location and the closest facility. In an obnoxious facility game, each agent wants to be far away from all facilities, and her utility is the distance from her location to the facility set. The objective of each agent is to minimize her cost or maximize her utility. An agent may lie if, by doing so, more benefit can be obtained. We are interested in social choice mechanisms that do not utilize payments. The game designer aims at a mechanism that is strategy-proof, in the sense that any agent cannot benefit by misreporting her address, or, even better, group strategy-proof, in the sense that any coalition of agents cannot all benefit by lying. Meanwhile, it is desirable to have the mechanism to be approximately optimal with respect to a chosen objective function. Several models for such approximation mechanism design without money for facility games have been proposed. In this paper we briefly review these models and related results for both deterministic and randomized mechanisms, and meanwhile we present a general framework for approximation mechanism design without money for facility games

Extreme Sensitivity of the Superconducting State in Thin Films

All non-interacting two-dimensional electronic systems are expected to exhibit an insulating ground state. This conspicuous absence of the metallic phase has been challenged only in the case of low-disorder, low density, semiconducting systems where strong interactions dominate the electronic state. Unexpectedly, over the last two decades, there have been multiple reports on the observation of a state with metallic characteristics on a variety of thin-film superconductors. To date, no theoretical explanation has been able to fully capture the existence of such a state for the large variety of superconductors exhibiting it. Here we show that for two very different thin-film superconductors, amorphous indium-oxide and a single-crystal of 2H-NbSe2, this metallic state can be eliminated by filtering external radiation. Our results show that these superconducting films are extremely sensitive to external perturbations leading to the suppression of superconductivity and the appearance of temperature independent, metallic like, transport at low temperatures. We relate the extreme sensitivity to the theoretical observation that, in two-dimensions, superconductivity is only marginally stable.Comment: 10 pages, 6 figure