Low-temperature illumination and annealing of ultra-high quality quantum wells

The effects of low temperature illumination and annealing on fractional quantum Hall (FQH) characteristics of a GaAs/AlGaAs quantum well are investigated. Illumination alone, below 1 K, decreases the density of the 2DEG electrons by more than an order of magnitude and resets the sample to a repeatable initial state. Subsequent thermal annealing at a few Kelvin restores the original density and dramatically improves FQH characteristics. A reliable illumination and annealing recipe is developed that yields an energy gap of 600 mK for the 5/2 state

Epigenetic Chromatin Silencing: Bistability and Front Propagation

The role of post-translational modification of histones in eukaryotic gene regulation is well recognized. Epigenetic silencing of genes via heritable chromatin modifications plays a major role in cell fate specification in higher organisms. We formulate a coarse-grained model of chromatin silencing in yeast and study the conditions under which the system becomes bistable, allowing for different epigenetic states. We also study the dynamics of the boundary between the two locally stable states of chromatin: silenced and unsilenced. The model could be of use in guiding the discussion on chromatin silencing in general. In the context of silencing in budding yeast, it helps us understand the phenotype of various mutants, some of which may be non-trivial to see without the help of a mathematical model. One such example is a mutation that reduces the rate of background acetylation of particular histone side-chains that competes with the deacetylation by Sir2p. The resulting negative feedback due to a Sir protein depletion effect gives rise to interesting counter-intuitive consequences. Our mathematical analysis brings forth the different dynamical behaviors possible within the same molecular model and guides the formulation of more refined hypotheses that could be addressed experimentally.Comment: 19 pages, 5 figure

Microarray screening of Guillain-Barré syndrome sera for antibodies to glycolipid complexes

Objective: To characterize the patterns of autoantibodies to glycolipid complexes in a large cohort of Guillain-Barré syndrome (GBS) and control samples collected in Bangladesh using a newly developed microarray technique. Methods: Twelve commonly studied glycolipids and lipids, plus their 66 possible heteromeric complexes, totaling 78 antigens, were applied to polyvinylidene fluoride–coated slides using a microarray printer. Arrays were probed with 266 GBS and 579 control sera (2 μL per serum, diluted 1/50) and bound immunoglobulin G detected with secondary antibody. Scanned arrays were subjected to statistical analyses. Results: Measuring antibodies to single targets was 9% less sensitive than to heteromeric complex targets (49.2% vs 58.3%) without significantly affecting specificity (83.9%–85.0%). The optimal screening protocol for GBS sera comprised a panel of 10 glycolipids (4 single glycolipids GM1, GA1, GD1a, GQ1b, and their 6 heteromeric complexes), resulting in an overall assay sensitivity of 64.3% and specificity of 77.1%. Notable heteromeric targets were GM1:GD1a, GM1:GQ1b, and GA1:GD1a, in which exclusive binding to the complex was observed. Conclusions: Rationalizing the screening protocol to capture the enormous diversity of glycolipid complexes can be achieved by miniaturizing the screening platform to a microarray platform, and applying simple bioinformatics to determine optimal sensitivity and specificity of the targets. Glycolipid complexes are an important category of glycolipid antigens in autoimmune neuropathy cases that require specific analytical and bioinformatics methods for optimal detection

Dampak Frekuensi Pernapasan Predialisis terhadap Kram Otot Intradialisis di RSUD Panembahan Senopati Bantul

Proses hemodialisis juga sering menimbulkan dampak kesakitan seperti terjadinya kram otot saat intradialisis. Tujuan penelitian ini untuk mengidentifikasi dampak meningkatnya frekuensi pernapasan terhadap kram otot intradialisis. Penelitian ini menggunakan metode kuantitatif dengan desain analitik cross sectional. Penelitian ini dilakukan di ruang hemodialisis RSUD Panembahan Senopati Bantul. Subyek penelitian ini diambil secara accidental sampling. Keseluruhan subyek penelitian ini adalah 91 responden. Peneliti mengukur frekuensi pernapasan predialisis dan mengkaji kram otot intradialisis. Penelitian ini menggunakan analisa bivariabel Chi-Square. Hasil analisa Chi-Square menunjukkan nilai p sebesar 0,020 yang berarti terdapat hubungan yang signifikan antara frekuensi napas predialisis terhadap kram otot intradialisis. Kram otot yang terjadi selama proses hemodialisis dapat terjadi karena adanya stress oksidatif selama intradialisis. Observasi frekuensi pernapasan dapat mengantisipasi adanya risiko stres oksidatif yang mungkin akan terjadi

Valuing Fed Cattle Using Objective Tenderness Measures

Beef tenderness is critical in consumer satisfaction with beef steak products. Current fed cattle valuation systems do not differentiate carcasses based upon tenderness variation. However, considerable research indicates consumers are willing to pay more for tender relative to tough beef steak. This article develops a tenderness-augmentation to current fed cattle grid pricing systems. Using a large set of actual carcasses, we determine that a tenderness-augmented price grid would reorder fed cattle value by on average nearly $5.00/cwt dressed relative to current valuation methods. Substantial opportunity is present to improve beef tenderness through new price signals to producers.beef quality, meat tenderness, cattle value, cattle price, Agribusiness, Farm Management, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Q11, Q13, M31,

Implementasi Ketersediaan Beras Dalam Rangka Ketahanan Pangan Di Kabupaten Batang

Availability of good rice is expected to maintain food security. However, riceavailability in Batang Regency decreases although the consumption of rice is always increases. When this occurs continuously, it is feared that there will be deficits that cause weak food security.Location of the research was in Badan Pelaksana Penyuluhan dan KetahananPangan Batang Regency. Selection of informants was done using a purposive sampling.To test the quality of the obtained data, technique of triangulation was employed. As the focus of study, implementation of the policy observed through results and process, based on the policy performance of observable indicators of effectiveness, efficiency, fairness, adequacy, responsiveness and accuracy. Based on theories of Edwards III, and Van Meter & Van Horn\u27s implementation model synthesis, acquired the factors that support and hinder the implementation of the policy, namely communications, disposition, bureaucratic structure and resources.Based on the results of this research, implementation of the policy on theavailability of rice on Batang has yet to pan out. There are still weakness in efficiency, fairness and effectiveness.The recommendations are (1) addition of equitable distribution and infrastructures; (2) equity of efforts increased production; (3) equitable socialization and counseling services; (4) monitoring during the production process; and (5) intensive socialization and counseling

Predicting global usages of resources endowed with local policies

The effective usages of computational resources are a primary concern of up-to-date distributed applications. In this paper, we present a methodology to reason about resource usages (acquisition, release, revision, ...), and therefore the proposed approach enables to predict bad usages of resources. Keeping in mind the interplay between local and global information occurring in the application-resource interactions, we model resources as entities with local policies and global properties governing the overall interactions. Formally, our model takes the shape of an extension of pi-calculus with primitives to manage resources. We develop a Control Flow Analysis computing a static approximation of process behaviour and therefore of the resource usages.Comment: In Proceedings FOCLASA 2011, arXiv:1107.584