Enabling III-V-based optoelectronics with low-cost dynamic hydride vapor phase epitaxy

Silicon is the dominant semiconductor in many semiconductor device applications for a variety of reasons, including both performance and cost. III-V materials have improved performance compared to silicon, but currently they are relegated to applications in high-value or niche markets due to the absence of a low-cost, high-quality production technique. Here we present an advance in III-V materials synthesis using hydride vapor phase epitaxy that has the potential to lower III-V semiconductor deposition costs by orders of magnitude while maintaining the requisite optoelectronic material quality that enables III-V-based technologies to outperform Si. We demonstrate the impacts of this advance by addressing the use of III-Vs in terrestrial photovoltaics, a highly cost-constrained market. The emergence of a low-cost III-V deposition technique will enable III-V electronic and opto-electronic devices, with all the benefits that they bring, to permeate throughout modern society.Comment: pre-prin

ECONOMICALLY OPTIMAL NITROGEN FERTILIZATION FOR YIELD AND PROTEIN IN HARD RED SPRING WHEAT

This analysis determines profit maximizing N fertilization levels of hard red spring wheat (HRSW) for various wheat prices, N prices, and protein-based HRSW price premium/discount (P/D) structures for south eastern Washington data. Fertilizer response data consisting of rates of N fertilization (lb/ac), grain yield (bu/ac), and grain protein (%) were used to statistically estimate regression relationships that predicted yield and protein in response to N. All predicted net return maximizing N, protein, and yield levels were within the data range. Increasing P/D incentives for protein increased optimal N, the expected economic result. At the high P/D structures, the P/D structure dominated N and wheat prices in determining optimal N application levels. Overall, net return-maximizing yields varied only modestly with changes in both N and wheat price in this data set. However, in all scenarios, as P/D incentives increased, net return maximizing N levels were beyond the level that resulted in maximum yield. At the two lowest P/D structures, which provided the lowest reward for protein, it was most profitable to fertilize for slightly less than 14% expected protein. These results indicate that it is not always profitable to use 14% protein as an N fertilization goal. Abbreviations: CT, conventional tillage; HRSW, hard red spring wheat; HRWW, hard red winter wheat; N, nitrogen; NO3, nitrate; NT, No Tillage; P/D, premium/discount; SWSW, soft white spring wheat; SWW, soft white wheat.Crop Production/Industries,

Interactions of cultures and top people of Wikipedia from ranking of 24 language editions

Wikipedia is a huge global repository of human knowledge, that can be leveraged to investigate interwinements between cultures. With this aim, we apply methods of Markov chains and Google matrix, for the analysis of the hyperlink networks of 24 Wikipedia language editions, and rank all their articles by PageRank, 2DRank and CheiRank algorithms. Using automatic extraction of people names, we obtain the top 100 historical figures, for each edition and for each algorithm. We investigate their spatial, temporal, and gender distributions in dependence of their cultural origins. Our study demonstrates not only the existence of skewness with local figures, mainly recognized only in their own cultures, but also the existence of global historical figures appearing in a large number of editions. By determining the birth time and place of these persons, we perform an analysis of the evolution of such figures through 35 centuries of human history for each language, thus recovering interactions and entanglement of cultures over time. We also obtain the distributions of historical figures over world countries, highlighting geographical aspects of cross-cultural links. Considering historical figures who appear in multiple editions as interactions between cultures, we construct a network of cultures and identify the most influential cultures according to this network.Comment: 32 pages. 10 figures. Submitted for publication. Supporting information is available on http://www.quantware.ups-tlse.fr/QWLIB/topwikipeople

The Impact of Hydrodynamic Mixing on Supernova Progenitors

Recent multidimensional hydrodynamic simulations have demonstrated the importance of hydrodynamic motions in the convective boundary and radiative regions of stars to transport of energy, momentum, and composition. The impact of these processes increases with stellar mass. Stellar models which approximate this physics have been tested on several classes of observational problems. In this paper we examine the implications of the improved treatment on supernova progenitors. The improved models predict substantially different interior structures. We present pre-supernova conditions and simple explosion calculations from stellar models with and without the improved mixing treatment at 23 solar masses. The results differ substantially.Comment: 12 pages, 2 figures, accepted for publication in the Astrophysical Journal Letter

Urinalysis and Urinary Tract Infection: Update for Clinicians

Dysuria is a common presenting complaint of women and urinalysis is a valuable tool in the initial evaluation of this presentation. Clinicians need to be aware that pyuria is the best determinate of bacteriuria requiring therapy and that values significant for infection differ depending on the method of analysis. A hemocytometer yields a value of ≥ 10 WBC/ mm(3) significant for bacteriuria, while manual microscopy studies show ≥ 8 WBC/high-power field reliably predicts a positive urine culture. In cases of uncomplicated symptomatic urinary tract infection, a positive value for nitrites and leukocyte esterase by urine dipstick can be treated without the need for a urine culture. Automated urinalysis used widely in large volume laboratories provides more sensitive detection of leukocytes and bacteria in the urine.With automated microscopy, a value of > 2 WBC/hpf is significant pyuria indicative of inflammation of the urinary tract. In complicated cases such as pregnancy, recurrent infection or renal involvement, further evaluation is necessary including manual microscopy and urine culture with sensitivities

San Francisco Bay Area KIPP Schools: A Study of Early Implementation

Measures how well five San Francisco Bay Area schools have implemented the goals of the Knowledge Is Power Program during the first year of a three-year initiative to prepare underserved urban youth for college

Predicting host taxonomic information from viral genomes: a comparison of feature representations

The rise in metagenomics has led to an exponential growth in virus discovery. However, the majority of these new virus sequences have no assigned host. Current machine learning approaches to predicting virus host interactions have a tendency to focus on nucleotide features, ignoring other representations of genomic information. Here we investigate the predictive potential of features generated from four different ‘levels’ of viral genome representation: nucleotide, amino acid, amino acid properties and protein domains. This more fully exploits the biological information present in the virus genomes. Over a hundred and eighty binary datasets for infecting versus non-infecting viruses at all taxonomic ranks of both eukaryote and prokaryote hosts were compiled. The viral genomes were converted into the four different levels of genome representation and twenty feature sets were generated by extracting k-mer compositions and predicted protein domains. We trained and tested Support Vector Machine, SVM, classifiers to compare the predictive capacity of each of these feature sets for each dataset. Our results show that all levels of genome representation are consistently predictive of host taxonomy and that prediction k-mer composition improves with increasing k-mer length for all k-mer based features. Using a phylogenetically aware holdout method, we demonstrate that the predictive feature sets contain signals reflecting both the evolutionary relationship between the viruses infecting related hosts, and host-mimicry. Our results demonstrate that incorporating a range of complementary features, generated purely from virus genome sequences, leads to improved accuracy for a range of virus host prediction tasks enabling computational assignment of host taxonomic information