114 research outputs found

    Accountability and Blame Avoidance After Crises

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    The post-crisis accountability process is a purification ritual that serves to channel public emotions and enables re-equilibration after a severe disturbance of the sociopolitical order. Crisis accountability literature can be reviewed in terms of forums, actors, and consequences. This setup allows a systematic discussion of how crises impact: the accountability process in influencing its setting (the forum); the strategies of accountees and their opponents (actors); and the resulting outcomes in terms of reputation damage, sanctions, and restoration (consequences). There is a clear distinction between formal and informal accountability forums, with the media being almost exclusively informal, and judicial forums, accident investigators, and political inquiries having formal authority over accountability assessments. Yet, through the presence of formal authorities in media reporting, and because media frames influence the work of formal authorities, the different forums intensively interact in accountability processes. Looking at accountability strategies reveals that the number of actors involved in blame games is likely rising because of increasingly networked crisis responses, and the role of actors has become more important and personal in the crisis aftermath and accountability process. The consequences and success of individual actors in influencing the accountability outcomes is shaped by both institutional settings and individual skills and strategies. A current political power position that exceeds prior mistakes is an effective shield, and denial is the least effective though most commonly used strategy. Accountability processes remain a balancing act between rebuttal and repair. Yet after major crisis, renewal is possible, and post-crisis accountability can play a crucial role therein.Security and Global Affair

    Simple sequence repeat variation in the Daphnia pulex genome

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    Background: Simple sequence repeats (SSRs) are highly variable features of all genomes. Their rapid evolution makes them useful for tracing the evolutionary history of populations and investigating patterns of selection and mutation across gnomes. The recently sequenced Daphnia pulex genome provides us with a valuable data set to study the mode and tempo of SSR evolution, without the inherent biases that accompany marker selection. Results: Here we catalogue SSR loci in the Daphnia pulex genome with repeated motif sizes of 1-100 nucleotides with a minimum of 3 perfect repeats. We then used whole genome shotgun reads to determine the average heterozygosity of each SSR type and the relationship that it has to repeat number, motif size, motif sequence, and distribution of SSR loci. We find that SSR heterozygosity is motif specific, and positively correlated with repeat number as well as motif size. For non-repeat unit polymorphisms, we identify a motif-dependent end-nucleotide polymorphism bias that may contribute to the patterns of abundance for specific homopolymers, dimers, and trimers. Our observations confirm the high frequency of multiple unit variation (multistep) at large microsatellite loci, and further show that the occurrence of multiple unit variation is dependent on both repeat number and motif size. Using the Daphnia pulex genetic map, we show a positive correlation between dimer and trimer frequency and recombination. Conclusions: This genome-wide analysis of SSR variation in Daphnia pulex indicates that several aspects of SSR variation are motif dependent and suggests that a combination of unit length variation and end repeat biased base substitution contribute to the unique spectrum of SSR repeat loci

    Managing urinary tract infections

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    Urinary tract infections (UTI) are common in childhood. Presence of pyuria and bacteriuria in an appropriately collected urine sample are diagnostic of UTI. The risk of UTI is increased with an underlying urological abnormality such as vesicoureteral reflux, constipation, and voiding dysfunction. Patients with acute pyelonephritis are at risk of renal scarring and subsequent complications such as hypertension, proteinuria with and without FSGS, pregnancy-related complications and even end-stage renal failure. The relevance and the sequence of the renal imaging following initial UTI, and the role of antimicrobial prophylaxis and surgical intervention are currently undergoing an intense debate. Prompt treatment of UTI and appropriate follow-up of those at increased risk of recurrence and/or renal scarring are important

    What Is a Microsatellite: A Computational and Experimental Definition Based upon Repeat Mutational Behavior at A/T and GT/AC Repeats

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    Microsatellites are abundant in eukaryotic genomes and have high rates of strand slippage-induced repeat number alterations. They are popular genetic markers, and their mutations are associated with numerous neurological diseases. However, the minimal number of repeats required to constitute a microsatellite has been debated, and a definition of a microsatellite that considers its mutational behavior has been lacking. To define a microsatellite, we investigated slippage dynamics for a range of repeat sizes, utilizing two approaches. Computationally, we assessed length polymorphism at repeat loci in ten ENCODE regions resequenced in four human populations, assuming that the occurrence of polymorphism reflects strand slippage rates. Experimentally, we determined the in vitro DNA polymerase-mediated strand slippage error rates as a function of repeat number. In both approaches, we compared strand slippage rates at tandem repeats with the background slippage rates. We observed two distinct modes of mutational behavior. At small repeat numbers, slippage rates were low and indistinguishable from background measurements. A marked transition in mutability was observed as the repeat array lengthened, such that slippage rates at large repeat numbers were significantly higher than the background rates. For both mononucleotide and dinucleotide microsatellites studied, the transition length corresponded to a similar number of nucleotides (approximately 10). Thus, microsatellite threshold is determined not by the presence/absence of strand slippage at repeats but by an abrupt alteration in slippage rates relative to background. These findings have implications for understanding microsatellite mutagenesis, standardization of genome-wide microsatellite analyses, and predicting polymorphism levels of individual microsatellite loci

    Sources of variation for indoor nitrogen dioxide in rural residences of Ethiopia

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    <p>Abstract</p> <p>Background</p> <p>Unprocessed biomass fuel is the primary source of indoor air pollution (IAP) in developing countries. The use of biomass fuel has been linked with acute respiratory infections. This study assesses sources of variations associated with the level of indoor nitrogen dioxide (NO<sub>2</sub>).</p> <p>Materials and methods</p> <p>This study examines household factors affecting the level of indoor pollution by measuring NO<sub>2</sub>. Repeated measurements of NO<sub>2 </sub>were made using a passive diffusive sampler. A <it>Saltzman </it>colorimetric method using a spectrometer calibrated at 540 nm was employed to analyze the mass of NO<sub>2 </sub>on the collection filter that was then subjected to a mass transfer equation to calculate the level of NO<sub>2 </sub>for the 24 hours of sampling duration. Structured questionnaire was used to collect data on fuel use characteristics. Data entry and cleaning was done in EPI INFO version 6.04, while data was analyzed using SPSS version 15.0. Analysis of variance, multiple linear regression and linear mixed model were used to isolate determining factors contributing to the variation of NO<sub>2 </sub>concentration.</p> <p>Results</p> <p>A total of 17,215 air samples were fully analyzed during the study period. Wood and crop were principal source of household energy. Biomass fuel characteristics were strongly related to indoor NO<sub>2 </sub>concentration in one-way analysis of variance. There was variation in repeated measurements of indoor NO<sub>2 </sub>over time. In a linear mixed model regression analysis, highland setting, wet season, cooking, use of fire events at least twice a day, frequency of cooked food items, and interaction between ecology and season were predictors of indoor NO<sub>2 </sub>concentration. The volume of the housing unit and the presence of kitchen showed little relevance in the level of NO<sub>2 </sub>concentration.</p> <p>Conclusion</p> <p>Agro-ecology, season, purpose of fire events, frequency of fire activities, frequency of cooking and physical conditions of housing are predictors of NO<sub>2 </sub>concentration. Improved kitchen conditions and ventilation are highly recommended.</p

    Genome-Wide Influence of Indel Substitutions on Evolution of Bacteria of the PVC Superphylum, Revealed Using a Novel Computational Method

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    Whole-genome scans for positive Darwinian selection are widely used to detect evolution of genome novelty. Most approaches are based on evaluation of nonsynonymous to synonymous substitution rate ratio across evolutionary lineages. These methods are sensitive to saturation of synonymous sites and thus cannot be used to study evolution of distantly related organisms. In contrast, indels occur less frequently than amino acid replacements, accumulate more slowly, and can be employed to characterize evolution of diverged organisms. As indels are also subject to the forces of natural selection, they can generate functional changes through positive selection. Here, we present a new computational approach to detect selective constraints on indel substitutions at the whole-genome level for distantly related organisms. Our method is based on ancestral sequence reconstruction, takes into account the varying susceptibility of different types of secondary structure to indels, and according to simulation studies is conservative. We applied this newly developed framework to characterize the evolution of organisms of the Planctomycetes, Verrucomicrobia, Chlamydiae (PVC) bacterial superphylum. The superphylum contains organisms with unique cell biology, physiology, and diverse lifestyles. It includes bacteria with simple cell organization and more complex eukaryote-like compartmentalization. Lifestyles range from free-living organisms to obligate pathogens. In this study, we conduct a whole-genome level analysis of indel substitutions specific to evolutionary lineages of the PVC superphylum and found that indels evolved under positive selection on up to 12% of gene tree branches. We also analyzed possible functional consequences for several case studies of predicted indel events

    Detection and characterization of small insertion and deletion genetic variants in modern layer chicken genomes

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    Background: Small insertions and deletions (InDels) constitute the second most abundant class of genetic variants and have been found to be associated with many traits and diseases. The present study reports on the detection and characterisation of about 883 K high quality InDels from the whole-genome analysis of several modern layer chicken lines from diverse breeds. Results: To reduce the error rates seen in InDel detection, this study used the consensus set from two InDel-calling packages: SAMtools and Dindel, as well as stringent post-filtering criteria. By analysing sequence data from 163 chickens from 11 commercial and 5 experimental layer lines, this study detected about 883 K high quality consensus InDels with 93 % validation rate and an average density of 0.78 InDels/kb over the genome. Certain chromosomes, viz, GGAZ, 16, 22 and 25 showed very low densities of InDels whereas the highest rate was observed on GGA6. In spite of the higher recombination rates on microchromosomes, the InDel density on these chromosomes was generally lower relative to macrochromosomes possibly due to their higher gene density. About 43-87 % of the InDels were found to be fixed within each line. The majority of detected InDels (86 %) were 1-5 bases and about 63 % were non-repetitive in nature while the rest were tandem repeats of various motif types. Functional annotation identified 613 frameshift, 465 non-frameshift and 10 stop-gain/loss InDels. Apart from the frameshift and stopgain/loss InDels that are expected to affect the translation of protein sequences and their biological activity, 33 % of the non-frameshift were predicted as evolutionary intolerant with potential impact on protein functions. Moreover, about 2.5 % of the InDels coincided with the most-conserved elements previously mapped on the chicken genome and are likely to define functional elements. InDels potentially affecting protein function were found to be enriched for certain gene-classes e.g. those associated with cell proliferation, chromosome and Golgi organization, spermatogenesis, and muscle contraction. Conclusions: The large catalogue of InDels presented in this study along with their associated information such as functional annotation, estimated allele frequency, etc. are expected to serve as a rich resource for application in future research and breeding in the chicken
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