AIDing Contraception: HIV and Recent Trends in Abortion Rates

Since the onset of HIV/AIDS awareness in the early 1980s, much attention has centered around the substantial negative effects of the disease throughout the world. This paper provides evidence of a secondary effect the disease has had on sexual behavior in the United States. Using a difference-in-differences estimation framework and state level data, we show that the perceived threat of HIV resulted in a drop in unwanted pregnancies, as demonstrated by a lower incidence of abortions. Our results suggest that each additional reported case of HIV per 1,000 individuals resulted in 85.5 fewer abortions per 1,000 live births.HIV, abortion, fertility

Safe Architectural Design Principles

This report discusses architectures for safety-critical systems. The report summarises the existing literature in the area as well as the guidance provided by existing safety-critical system development standards. We discuss the three constituent functions of fault tolerant architectures: error detection, damage assessment and confinement and error recovery. We also consider methods for fault prevention

Hazard Analysis of Interactive Systems

This report discusses approaches to analysis of safety-critical systems for operator error. The report summarises the existing literature in the area as well as the guidance provided by existing safety-critical system development standards

Styles, textural evolution, and sulfur isotope systematics of Cu-rich sulfides from the Cambrian Whalesback volcanogenic massive sulfide deposit, central Newfoundland, Canada

The Whalesback Cu-rich volcanogenic massive sulfide deposit in the Newfoundland Appalachians is a highly deformed deposit found on a steep limb of a closed and boudinaged overturned fold. The deposit was intensely deformed at low temperature but medium pressure (>175 MPa) during the accretion of the composite Lushs Bight oceanic tract-Dashwoods terrane onto the Humber margin at ca. 480 Ma. The ore mineralogy consists of chalcopyrite, pyrrhotite, and pyrite with lesser sphalerite and trace Ag, Bi, and Hg tellurides. Four styles of sulfide mineralization are present: (1) disseminated (5%); (2) vein (50%); (3) breccia (25%); and (4) semimassive to massive (20%). Independent of mineralization style, massive pyrite and pyrrhotite (and some chalcopyrite) are commonly parallel to main S2 schistosity in the deposit, whereas late chalcopyrite piercement veins occur at a high angle to S2. The progressive increase in pressure and temperature produced a remobilization sequence wherein sphalerite was the first sulfide phase to cross the brittle-ductile boundary, followed by pyrrhotite and, finally, chalcopyrite. Maximum temperature was not high enough for the pyrite to cross the brittle-ductile boundary. Instead, pyrite grains were incorporated and transported by pyrrhotite and chalcopyrite during the ductile remobilization events, rounding and fracturing them. Remobilization of the sulfides occurred mainly by plastic flow, but some solution transport and reprecipitation is locally observed. In situ secondary ion mass spectrometry sulfur isotope geochemistry of sulfides yielded values of δ34S ranging from 2.7‰ to 4.7‰ for pyrite, 2.1‰ to 4.0‰ for pyrrhotite, and 1.3‰ to 4.7‰ for chalcopyrite. Sulfur isotope modeling suggests that at least 60% of the sulfur was derived from leaching of igneous rocks (i.e., basalts), with the remainder derived from thermochemical sulfate reduction of seawater sulfate during alteration of the basalts by seawater. At the deposit scale, sulfur isotopes retained their original signature and did not reequilibrate during the secondary deformation and remobilization events.PostprintPeer reviewe

Experimental and Theoretical (e,2e) Ionization Cross Sections for a Hydrogen Target at 75.3 eV Incident Energy in a Coplanar Asymmetric Geometry

Very recently it was shown that the molecular three-body distorted wave (M3DW) approach gives good agreement with the shape of the experimental data for electron-impact ionization of H2 in a coplanar symmetric geometry, providing the incident electrons have an energy of 35 eV or greater. One of the weaknesses of these studies was that only the shape of the cross section could be compared to experiment, since there was no absolute or relative normalization of the data. Here we report a joint experimental/theoretical study of electron-impact ionization of H2 in a coplanar asymmetric geometry where the energy of the incident electron was fixed, and different pairs of final state electron energies were used. In this case, the experimental data can be normalized such that only one renormalization factor is required. It is shown that the M3DW is pretty good in agreement with experiment. However, a better treatment of polarization and exchange between the continuum and bound state electrons is required before quantitative agreement between experiment and theory is achieved

The Associations Between Park Environments and Park Use in Southern US Communities

Purpose To document park use and park and neighborhood environment characteristics in rural communities, and to examine the relationship between park characteristics and park use. Methods The System for Observing Play and Recreation in Communities measured use in 42 target areas across 6 community parks in May 2010 and October 2010. Direct observation instruments were used to assess park and neighborhood environment characteristics. Logistic regression was used to determine the relationship between the condition, number of amenities, and number of incivilities in a target area with target area use. Findings Ninety‐seven people were observed across all parks during May 2010 data collection and 116 people during October 2010 data collection. Low park quality index scores and unfavorable neighborhood environment characteristics were observed. There was a significant positive association between number of incivilities in a target area and target area use (OR = 1.91; 95% CI: 1.09‐3.38; P = .03). Conclusions The number of people observed using the parks in this study was low, and it was considerably less than the number observed in other studies. The objective park and neighborhood environment characteristics documented in this study provide a more comprehensive understanding of parks than other studies. Further examining the complex relationship between park and neighborhood environment characteristics and park use is important, as it can inform park administrators and city planners of characteristics that are best able to attract visitors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108592/1/jrh12071.pd

AIDing Contraception: HIV and Recent Trends in Abortion Rates

Since the onset of HIV/AIDS awareness in the early 1980s, much attention has centered around the substantial negative effects of the disease throughout the world. This paper provides evidence of a secondary effect the disease has had on sexual behavior in the United States. Using a difference-in-differences estimation framework and state level data, we show that the perceived threat of HIV resulted in a drop in unwanted pregnancies, as demonstrated by a lower incidence of abortions. Our results suggest that each additional reported case of HIV per 1,000 individuals resulted in 85.5 fewer abortions per 1,000 live births

AIDing Contraception: HIV and Recent Trends in Abortion Rates

Since the onset of HIV/AIDS awareness in the early 1980s, much attention has centered around the substantial negative effects of the disease throughout the world. This paper provides evidence of a secondary effect the disease has had on sexual behavior in the United States. Using a difference-in-differences estimation framework and state level data, we show that the perceived threat of HIV resulted in a drop in unwanted pregnancies, as demonstrated by a lower incidence of abortions. Our results suggest that each additional reported case of HIV per 1,000 individuals resulted in 85.5 fewer abortions per 1,000 live births

Extending and Evaluating a Pattern Language for Safety-Critical User Interfaces

This paper describes the extension and evaluation of an existing pattern language for safety-critical user interface development. The patterns were updated and new patterns were added by examining existing medical systems. The new patterns were found by generating problem definitions from perceived exemplary solutions. This method of pattern development and its application is described. A qualitative evaluation of the pattern language was performed by designing a safety-critical user interface for a hypothetical radiation therapy machine. Discussion of the design process focuses on the usefulness of our patterns as a design tool for safety-critical user interfaces

Genome-wide mapping of histone H3 lysine 4 trimethylation in Eucalyptus grandis developing xylem

BACKGROUND : Histone modifications play an integral role in plant development, but have been poorly studied in woody plants. Investigating chromatin organization in wood-forming tissue and its role in regulating gene expression allows us to understand the mechanisms underlying cellular differentiation during xylogenesis (wood formation) and identify novel functional regions in plant genomes. However, woody tissue poses unique challenges for using high-throughput chromatin immunoprecipitation (ChIP) techniques for studying genome-wide histone modifications in vivo. We investigated the role of the modified histone H3K4me3 (trimethylated lysine 4 of histone H3) in gene expression during the early stages of wood formation using ChIP-seq in Eucalyptus grandis, a woody biomass model. RESULTS : Plant chromatin fixation and isolation protocols were optimized for developing xylem tissue collected from field-grown E. grandis trees. A “nano-ChIP-seq” procedure was employed for ChIP DNA amplification. Over 9 million H3K4me3 ChIP-seq and 18 million control paired-end reads were mapped to the E. grandis reference genome for peak-calling using Model-based Analysis of ChIP-Seq. The 12,177 significant H3K4me3 peaks identified covered ~1.5% of the genome and overlapped some 9,623 protein-coding genes and 38 noncoding RNAs. H3K4me3 library coverage, peaking ~600 - 700 bp downstream of the transcription start site, was highly correlated with gene expression levels measured with RNA-seq. Overall, H3K4me3-enriched genes tended to be less tissue-specific than unenriched genes and were overrepresented for general cellular metabolism and development gene ontology terms. Relative expression of H3K4me3-enriched genes in developing secondary xylem was higher than unenriched genes, however, and highly expressed secondary cell wall-related genes were enriched for H3K4me3 as validated using ChIP-qPCR. CONCLUSIONS : In this first genome-wide analysis of a modified histone in a woody tissue, we optimized a ChIP-seq procedure suitable for field-collected samples. In developing E. grandis xylem, H3K4me3 enrichment is an indicator of active transcription, consistent with its known role in sustaining pre-initiation complex formation in yeast. The H3K4me3 ChIP-seq data from this study paves the way to understanding the chromatin landscape and epigenomic architecture of xylogenesis in plants, and complements RNA-seq evidence of gene expression for the future improvement of the E. grandis genome annotation.Additional file 1: Supplementary Note S1.Additional file 2: Figure S1, Figure S2, Figure S3, Figure S4, Figure S5, Figure S6, Figure S6, Figure S7, Figure S8, Figure S9, Figure S10, Figure S11, Figure S12, Figure S13, Figure S14, Figure S15, Figure S16.Additional file 3: Table S1, Table S2, Table S3, Table S4, Table S5, Table S6, Table S7.Additional file 4: Genomic locations and fragment coverage of significant H3K4me3 peaks.Additional file 5: Genomic locations of annotated genes overlapping with significant H3K4me3 peaks.Additional file 6: Genomic locations of low-confidence gene models overlapping with significant H3K4me3 peaks.SH, EM and AM acknowledge funding from the Department of Science and Technology (DST), South Africa, the National Research Foundation of South Africa (NRF) Incentive Funding for Rated Researchers Grant (UID 81111) and NRF Bioinformatics and Functional Genomics Program (UID 71255, UID 86936), Sappi and Mondi through the Forest Molecular Genetics (FMG) Program at the University of Pretoria (UP), and the Technology and Human Resources for Industry Program (THRIP) (UID 80118). AG acknowledges funding from USDA National Institute of Food and Agriculture and the Office of Science (BER), US Department of Energy.http://www.biomedcentral.com/bmcplantbiolam201