Negative Specific Heat of a Magnetically Self-Confined Plasma Torus

It is shown that the thermodynamic maximum entropy principle predicts negative specific heat for a stationary magnetically self-confined current-carrying plasma torus. Implications for the magnetic self-confinement of fusion plasma are considered.Comment: 10p., LaTeX, 2 eps figure file

Superconducting Quantum Point contacts and Maxwell Potential

The quantization of the current in a superconducting quantum point contact is reviewed and the critical current is discussed at different temperatures depending on the carrier concentration as well by suggesting a constant potential in the semiconductor and then a Maxwell potential. When the Fermi wave length is comparable with the constriction width we showed that the critical current has a step-like variation as a function of the constriction width and the carrier concentration.Comment: 13 pages, 8 figures, some figures are clarified; scheduled to appear in an issue in MPLB Vo.21, (2007

Development of a novel clinical scoring system for on-farm diagnosis of bovine respiratory disease in pre-weaned dairy calves.

Several clinical scoring systems for diagnosis of bovine respiratory disease (BRD) in calves have been proposed. However, such systems were based on subjective judgment, rather than statistical methods, to weight scores. Data from a pair-matched case-control study on a California calf raising facility was used to develop three novel scoring systems to diagnose BRD in preweaned dairy calves. Disease status was assigned using both clinical signs and diagnostic test results for BRD-associated pathogens. Regression coefficients were used to weight score values. The systems presented use nasal and ocular discharge, rectal temperature, ear and head carriage, coughing, and respiratory quality as predictors. The systems developed in this research utilize fewer severity categories of clinical signs, require less calf handling, and had excellent agreement (Kappa > 0.8) when compared to an earlier scoring system. The first scoring system dichotomized all clinical predictors but required inducing a cough. The second scoring system removed induced cough as a clinical abnormality but required distinguishing between three levels of nasal discharge severity. The third system removed induced cough and forced a dichotomized variable for nasal discharge. The first system presented in this study used the following predictors and assigned values: coughing (induced or spontaneous coughing, 2 points), nasal discharge (any discharge, 3 points), ocular discharge (any discharge, 2 points), ear and head carriage (ear droop or head tilt, 5 points), fever (≥39.2°C or 102.5°F, 2 points), and respiratory quality (abnormal respiration, 2 points). Calves were categorized "BRD positive" if their total score was ≥4. This system correctly classified 95.4% cases and 88.6% controls. The second presented system categorized the predictors and assigned weights as follows: coughing (spontaneous only, 2 points), mild nasal discharge (unilateral, serous, or watery discharge, 3 points), moderate to severe nasal discharge (bilateral, cloudy, mucoid, mucopurlent, or copious discharge, 5 points), ocular discharge (any discharge, 1 point), ear and head carriage (ear droop or head tilt, 5 points), fever (≥39.2°C, 2 points), and respiratory quality (abnormal respiration, 2 points). Calves were categorized "BRD positive" if their total score was ≥4. This system correctly classified 89.3% cases and 92.8% controls. The third presented system used the following predictors and scores: coughing (spontaneous only, 2 points), nasal discharge (any, 4 points), ocular discharge (any, 2 points), ear and head carriage (ear droop or head tilt, 5 points), fever (≥39.2°C, 2 points), and respiratory quality (abnormal respiration, 2 points). Calves were categorized "BRD positive" if their total score was ≥5. This system correctly classified 89.4% cases and 90.8% controls. Each of the proposed systems offer few levels of clinical signs and data-based weights for on-farm diagnosis of BRD in dairy calves

Minimal-memory realization of pearl-necklace encoders of general quantum convolutional codes

Quantum convolutional codes, like their classical counterparts, promise to offer higher error correction performance than block codes of equivalent encoding complexity, and are expected to find important applications in reliable quantum communication where a continuous stream of qubits is transmitted. Grassl and Roetteler devised an algorithm to encode a quantum convolutional code with a "pearl-necklace encoder." Despite their theoretical significance as a neat way of representing quantum convolutional codes, they are not well-suited to practical realization. In fact, there is no straightforward way to implement any given pearl-necklace structure. This paper closes the gap between theoretical representation and practical implementation. In our previous work, we presented an efficient algorithm for finding a minimal-memory realization of a pearl-necklace encoder for Calderbank-Shor-Steane (CSS) convolutional codes. This work extends our previous work and presents an algorithm for turning a pearl-necklace encoder for a general (non-CSS) quantum convolutional code into a realizable quantum convolutional encoder. We show that a minimal-memory realization depends on the commutativity relations between the gate strings in the pearl-necklace encoder. We find a realization by means of a weighted graph which details the non-commutative paths through the pearl-necklace. The weight of the longest path in this graph is equal to the minimal amount of memory needed to implement the encoder. The algorithm has a polynomial-time complexity in the number of gate strings in the pearl-necklace encoder.Comment: 16 pages, 5 figures; extends paper arXiv:1004.5179v

Use of Contingent Valuation Analysis in a Developing Country: Market Perceptions of Contamination on Johannesburg’s Mine Dumps

This study reports the results of a contingent valuation (CV) survey that was carried out in Johannesburg, South Africa. Students at Wits University conducted more than 300 face-to-face interviews with Africans living and/or working in Soweto, an African township located on the outskirts of Johannesburg, and nearby areas. The questions they asked were designed to determine the perceptions of risk regarding airborne mine dust and radon, a naturally occurring gas, and the effect that these perceptions had on the valuation of residential properties impacted by these substances. A probit model was used to evaluate the determinants of bidder behavior, using respondent demographics and other characteristics as independent variables. Residential property discounts for potentially contaminated housing sites by marginal bidders at the top of the market varied from -24% to -50%. Research issues in developing countries were addressed. Contingent valuation results in South Africa were compared to published results in the United States.

Optimal Land Use for Rainfall-Runoff Transformation in Wae Ruhu Watershed

Flooding hit the island of Ambon in 2012 and 2013. Many analyzes has been developed to estimate the cause of the flooding. The study aims topredict optimal land management for reducing run-off. The method is simulation of CN value based on spatial analysis on watershed characteristics.The rainfall can\u27t be managed by watershed. The level of run-off can be determined by CN value that depends on the type of land cover. The resultshows that the land cover has changed about 90 ha, with the higher rainfall intensity is 2.118 in 2013. The result of simulation indicated that tochange of shrub and bare land, mix dryland forest, and secondary dryland forest with agroforestry. Agroforestry can decrease run-off amount 0,86%.The change of land cover and high rainfall are the main factors that caused the flooding in 2012 and 2013. It is necessary to add a rainfallobservation station so that the observation of surface flow can be done well