Trauma-Related Mortality among Adults in Rural Western Kenya: Characterising Deaths Using Data from a Health and Demographic Surveillance System

Background

Information on trauma-related deaths in low and middle income countries is limited but needed to target public health interventions. Data from a health and demographic surveillance system (HDSS) were examined to characterise such deaths in rural western Kenya.

Methods And Findings

Verbal autopsy data were analysed. Of 11,147 adult deaths between 2003 and 2008, 447 (4%) were attributed to trauma; 71% of these were in males. Trauma contributed 17% of all deaths in males 15 to 24 years; on a population basis mortality rates were greatest in persons over 65 years. Intentional causes accounted for a higher proportion of male than female deaths (RR 2.04, 1.37-3.04) and a higher proportion of deaths of those aged 15 to 65 than older people. Main causes in males were assaults (n=79, 25%) and road traffic injuries (n=47, 15%); and falls for females (n=17, 13%). A significantly greater proportion of deaths from poisoning (RR 5.0, 2.7-9.4) and assault (RR 1.8, 1.2-2.6) occurred among regular consumers of alcohol than among non-regular drinkers. In multivariate analysis, males had a 4-fold higher risk of death from trauma than females (Adjusted Relative Risk; ARR 4.0; 95% CI 1.7-9.4); risk of a trauma death rose with age, with the elderly at 7-fold higher risk (ARR 7.3, 1.1-49.2). Absence of care was the strongest predictor of trauma death (ARR 12.2, 9.4-15.8). Trauma-related deaths were higher among regular alcohol drinkers (ARR 1.5, 1.1-1.9) compared with non-regular drinkers.

Conclusions

While trauma accounts for a small proportion of deaths in this rural area with a high prevalence of HIV, TB and malaria, preventive interventions such as improved road safety, home safety strategies for the elderly, and curbing harmful use of alcohol, are available and could help diminish this burden. Improvements in systems to record underlying causes of death from trauma are required.     

Molecular and morphological evidence support four new species in the genus Muscodor from northern Thailand

The genus Muscodor comprises fungal endophytes which produce mixtures of volatile compounds (VOCs) with antimicrobial activities. In the present study, four novel species, Muscodor musae, M. oryzae, M. suthepensis and M. equiseti were isolated from Musa acuminata, Oryza rufipogon, Cinnamomum bejolghota and Equisetum debile, respectively; these are medicinal plants of northern Thailand. The new Muscodor species are distinguished based on morphological and physiological characteristics and on molecular analysis of ITS-rDNA. Volatile compound analysis showed that 2-methylpropanoic acid was the main VOCs produced by M. musae, M. suthepensis and M. equiseti. The mixed volatiles from each fungus showed in vitro antimicrobial activity. Muscodor suthepensis had the highest antifungal activity.     

Halogen bond tunability II: the varying roles of electrostatic and dispersion contributions to attraction in halogen bonds

In a previous study we investigated the effects of aromatic fluorine substitution on the strengths of the halogen bonds in halobenzene…acetone complexes (halo?=?chloro, bromo, and iodo). In this work, we have examined the origins of these halogen bonds (excluding the iodo systems), more specifically, the relative contributions of electrostatic and dispersion forces in these interactions and how these contributions change when halogen σ-holes are modified. These studies have been carried out using density functional symmetry adapted perturbation theory (DFT-SAPT) and through analyses of intermolecular correlation energies and molecular electrostatic potentials. It is found that electrostatic and dispersion contributions to attraction in halogen bonds vary from complex to complex, but are generally quite similar in magnitude. Not surprisingly, increasing the size and positive nature of a halogen’s σ-hole dramatically enhances the strength of the electrostatic component of the halogen bonding interaction. Not so obviously, halogens with larger, more positive σ-holes tend to exhibit weaker dispersion interactions, which is attributable to the lower local polarizabilities of the larger σ-holes.

Nanoporous Polytetrafluoroethylene/Silica Composite Separator as a High‐Performance All‐Vanadium Redox Flow Battery Membrane

A novel low‐cost nanoporous polytetrafluoroethylene (PTFE)/silica composite separator has been prepared and evaluated for its use in an all‐vanadium redox flow battery (VRB). The separator consists of silica particles enmeshed in a PTFE fibril matrix. It possesses unique nanoporous structures with an average pore size of 38 nm and a porosity of 48%. These pores function as the ion transport channels during redox flow battery operation. This separator provides excellent electrochemical performance in the mixed‐acid VRB system. The VRB using this separator delivers impressive energy efficiency, rate capability, and temperature tolerance. In additon, the flow cell using the novel separator also demonstrates an exceptional capacity retention capability over extended cycling, thus offering excellent stability for long‐term operation. The characteristics of low cost, excellent electrochemical performance and proven chemical stability afford the PTFE/silica nanoporous separator great potential as a substitute for the Nafion membrane used in VRB applications.     

Extending the coverage of spectral libraries: A neighbor‐based approach to predicting intensities of peptide fragmentation spectra

Searching spectral libraries in MS/MS is an important new approach to improving the quality of peptide and protein identification. The idea relies on the observation that ion intensities in an MS/MS spectrum of a given peptide are generally reproducible across experiments, and thus, matching between spectra from an experiment and the spectra of previously identified peptides stored in a spectral library can lead to better peptide identification compared to the traditional database search. However, the use of libraries is greatly limited by their coverage of peptide sequences: even for well‐studied organisms a large fraction of peptides have not been previously identified. To address this issue, we propose to expand spectral libraries by predicting the MS/MS spectra of peptides based on the spectra of peptides with similar sequences. We first demonstrate that the intensity patterns of dominant fragment ions between similar peptides tend to be similar. In accordance with this observation, we develop a neighbor‐based approach that first selects peptides that are likely to have spectra similar to the target peptide and then combines their spectra using a weighted K‐nearest neighbor method to accurately predict fragment ion intensities corresponding to the target peptide. This approach has the potential to predict spectra for every peptide in the proteome. When rigorous quality criteria are applied, we estimate that the method increases the coverage of spectral libraries available from the National Institute of Standards and Technology by 20–60%, although the values vary with peptide length and charge state. We find that the overall best search performance is achieved when spectral libraries are supplemented by the high quality predicted spectra.     

High genetic diversity within the morphologically conservative dwarf loach, Kichulchoia brevifasciata (Teleostei: Cobitidae), an endangered freshwater fish from South Korea

The dwarf loach, Kichulchoia brevifasciata, is a primary freshwater fish endemic to South Korea (Republic of Korea). Due to its limited geographic range, special habitat requirements, and scarcity, this species has been considered one of the most endangered cobitid loaches in the world. Gene tree and species tree reconstruction derived from mitochondrial and nuclear sequence data supports the exclusivity of K. brevifasciata and the existence of two highly distinct genetic lineages (eastern and western lineages). Intraspecific genetic variation based on the corrected genetic distance ranged from 0.0013 to 0.0017 (cytochrome b) and 0–0.0012 (nuclear loci) within each lineage and 0.0349 (cytochrome b) and 0.0037–0.0104 (nuclear loci) between the lineages. Although morphologically homogeneous, eastern and western lineages were estimated to have diverged roughly 2.79 million years ago (4.25–1.42, 95 % HPD). Future conservation efforts for K. brevifasciata should consider these genetically distinct lineages as separate evolutionary entities and adopt conservation efforts accordingly.     

Indirect Evolution of Hybrid Lethality Due to Linkage with Selected Locus in Mimulus guttatus

Most species are superbly and intricately adapted to the environments in which they live. Adaptive evolution by natural selection is the primary force shaping biological diversity. Differences between closely related species in ecologically selected characters such as habitat preference, reproductive timing, courtship behavior, or pollinator attraction may prevent interbreeding in nature, causing reproductive isolation. But does ecological adaptation cause reproductive incompatibilities such as hybrid sterility or lethality? Although several genes causing hybrid incompatibilities have been identified, there is intense debate over whether the genes that contribute to ecological adaptations also cause hybrid incompatibilities. Thirty years ago, a genetic study of local adaptation to copper mine soils in the wildflower Mimulus guttatus identified a locus that appeared to cause copper tolerance and hybrid lethality in crosses to other populations. But do copper tolerance and hybrid lethality have the same molecular genetic basis? Here we show, using high-resolution genome mapping, that copper tolerance and hybrid lethality are not caused by the same gene but are in fact separately controlled by two tightly linked loci. We further show that selection on the copper tolerance locus indirectly caused the hybrid incompatibility allele to go to high frequency in the copper mine population because of hitchhiking. Our results provide a new twist on Darwin''s original supposition that hybrid incompatibilities evolve as an incidental by-product of ordinary adaptation to the environment.     

The Oxytricha trifallax Macronuclear Genome: A Complex Eukaryotic Genome with 16,000 Tiny Chromosomes

The macronuclear genome of the ciliate Oxytricha trifallax displays an extreme and unique eukaryotic genome architecture with extensive genomic variation. During sexual genome development, the expressed, somatic macronuclear genome is whittled down to the genic portion of a small fraction (∼5%) of its precursor “silent” germline micronuclear genome by a process of “unscrambling” and fragmentation. The tiny macronuclear “nanochromosomes” typically encode single, protein-coding genes (a small portion, 10%, encode 2–8 genes), have minimal noncoding regions, and are differentially amplified to an average of ∼2,000 copies. We report the high-quality genome assembly of ∼16,000 complete nanochromosomes (∼50 Mb haploid genome size) that vary from 469 bp to 66 kb long (mean ∼3.2 kb) and encode ∼18,500 genes. Alternative DNA fragmentation processes ∼10% of the nanochromosomes into multiple isoforms that usually encode complete genes. Nucleotide diversity in the macronucleus is very high (SNP heterozygosity is ∼4.0%), suggesting that Oxytricha trifallax may have one of the largest known effective population sizes of eukaryotes. Comparison to other ciliates with nonscrambled genomes and long macronuclear chromosomes (on the order of 100 kb) suggests several candidate proteins that could be involved in genome rearrangement, including domesticated MULE and IS1595-like DDE transposases. The assembly of the highly fragmented Oxytricha macronuclear genome is the first completed genome with such an unusual architecture. This genome sequence provides tantalizing glimpses into novel molecular biology and evolution. For example, Oxytricha maintains tens of millions of telomeres per cell and has also evolved an intriguing expansion of telomere end-binding proteins. In conjunction with the micronuclear genome in progress, the O. trifallax macronuclear genome will provide an invaluable resource for investigating programmed genome rearrangements, complementing studies of rearrangements arising during evolution and disease.