1,370 research outputs found

    Book Reviews

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    Book reviews of: Bound in Wedlock: Slave and Free Black Marriage in the Nineteenth Century. By Tera W. Hunter. (Cambridge: The Belknap Press of Harvard University Press, 2017. 404 pp. 29.95,cloth.ISBN:9780674045712.)DeltaEpiphany:RobertF.KennedyinMississippi.ByEllenB.Meacham.(Jackson:UniversityPressofMississippi,2018.Acknowledgements,sourcenotes,bibliography,aboutthephotographers,index,Pp.xi,293.29.95, cloth. ISBN: 9780674045712.) Delta Epiphany: Robert F. Kennedy in Mississippi. By Ellen B. Meacham. (Jackson: University Press of Mississippi, 2018. Acknowledgements, source notes, bibliography, about the photographers, index, Pp. xi, 293. 28 cloth. ISBN 9781496817457.) Let the People See: The Story of Emmett Till. By Elliott J. Gorn. (New York: Oxford University Press, 2018. Acknowledgements, source notes, bibliography, index, Pp. xi, 400. 27.95hardcover.ISBN:9780199335122.)TheOrdealoftheReunion:ANewHistoryofReconstruction.ByMarkWahlgrenSummers.(ChapelHill:TheUniversityofNorthCarolinaPress,2014.528pp.,21halftones,notes,bibl.,index.27.95 hardcover. ISBN: 9780199335122.) The Ordeal of the Reunion: A New History of Reconstruction. By Mark Wahlgren Summers. (Chapel Hill: The University of North Carolina Press, 2014. 528 pp., 21 halftones, notes, bibl., index. 40.00 cloth. ISBN: 978-1-4696-1757-2.) Stepdaughters of History: Southern Women and the American Civil War. By Catherine Clinton. (Baton Rouge: Louisiana State University Press, 2016. 48.00hardback.ISBN:978807164570.)FrontiersofScience:ImperialismandNaturalKnowledgeintheGulfSouthBorderlands,15001850.ByCameronB.Strang.(ChapelHill,NC:UniversityofNorthCarolinaPress,2018.Acknowledgements,illustrations,index.Pp.vii,357.48.00 hardback. ISBN: 978807164570.) Frontiers of Science: Imperialism and Natural Knowledge in the Gulf South Borderlands, 1500- 1850. By Cameron B. Strang. (Chapel Hill, NC: University of North Carolina Press, 2018. Acknowledgements, illustrations, index. Pp. vii, 357. 39.95 Cloth. ISBN: 9781469640471.) Vicksburg, Grant’s Campaign that Broke the Confederacy. By Donald L. Miller. (New York: Simon & Schuster, 2019. Notes, illustrations, index. Pp. 663. $35.00.

    Correlated effects of ocean acidification and warming on behavioral and metabolic traits of a large pelagic fish

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    Ocean acidification and warming are co-occurring stressors, yet their effects on early life stages of large pelagic fishes are not well known. Here, we determined the effects of elevated CO2 and temperature at levels projected for the end of the century on activity levels, boldness, and metabolic traits (i.e., oxygen uptake rates) in larval kingfish (Seriola lalandi), a large pelagic fish with a circumglobal distribution. We also examined correlations between these behavioral and physiological traits measured under different treatments. Kingfish were reared from the egg stage to 25 days post-hatch in a full factorial design of ambient and elevated CO2 (~500 µatm and ~1000 µatm) and temperature (21 °C and 25 °C). Activity levels were higher in fish from the elevated temperature treatment compared with fish reared under ambient temperature. However, elevated CO2 did not affect activity, and boldness was not affected by either elevated CO2 or temperature. Both elevated CO2 and temperature resulted in increased resting oxygen uptake rates compared to fish reared under ambient conditions, but neither affected maximum oxygen uptake rates nor aerobic scope. Resting oxygen uptake rates and boldness were negatively correlated under ambient temperature, but positively correlated under elevated temperature. Maximum oxygen uptake rates and boldness were also negatively correlated under ambient temperature. These findings suggest that elevated temperature has a greater impact on behavioral and physiological traits of larval kingfish than elevated CO2. However, elevated CO2 exposure did increase resting oxygen uptake rates and interact with temperature in complex ways. Our results provide novel behavioral and physiological data on the responses of the larval stage of a large pelagic fish to ocean acidification and warming conditions, demonstrate correlations between these traits, and suggest that these correlations could influence the direction and pace of adaptation to global climate change

    Adaptive Comparative Judgement: A Tool to Support Students’ Assessment Literacy

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    Comparative judgment in assessment is a process whereby repeated comparison of two items (e.g., assessment answers) can allow an accurate ranking of all the submissions to be achieved. In adaptive comparative judgment (ACJ), technology is used to automate the process and present pairs of pieces of work over iterative cycles. An online ACJ system was used to present students with work prepared by a previous cohort at the same stage of their studies. Objective marks given to the work by experienced faculty were compared to the rankings given to the work by a cohort of veterinary students (n=154). Each student was required to review and judge 20 answers provided by the previous cohort to a free-text short answer question. The time that students spent on the judgment tasks was recorded, and students were asked to reflect on their experiences after engaging with the task. There was a strong positive correlation between student ranking and faculty marking. A weak positive correlation was found between the time students spent on the judgments and their performance on the part of their own examination that contained questions in the same format. Slightly less than half of the students agreed that the exercise was a good use of their time, but 78% agreed that they had learned from the process. Qualitative data highlighted different levels of benefit from the simplest aspect of learning more about the topic to an appreciation of the more generic lessons to be learned

    Organ health and development in larval kingfish are unaffected by ocean acidification and warming

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    Anthropogenic CO₂ emissions are causing global ocean warming and ocean acidification. The early life stages of some marine fish are vulnerable to elevated ocean temperatures and CO₂ concentrations, with lowered survival and growth rates most frequently documented. Underlying these effects, damage to different organs has been found as a response to elevated CO₂ in larvae of several species of marine fish, yet the combined effects of acidification and warming on organ health are unknown. Yellowtail kingfish, Seriola lalandi, a circumglobal subtropical pelagic fish of high commercial and recreational value, were reared from fertilization under control (21 °C) and elevated (25 °C) temperature conditions fully crossed with control (500 µatm) and elevated (1,000 µatm) pCO₂ conditions. Larvae were sampled at 11 days and 21 days post hatch for histological analysis of the eye, gills, gut, liver, pancreas, kidney and liver. Previous work found elevated temperature, but not elevated CO₂, significantly reduced larval kingfish survival while increasing growth and developmental rate. The current histological analysis aimed to determine whether there were additional sublethal effects on organ condition and development and whether underlying organ damage could be responsible for the documented effects of temperature on survivorship. While damage to different organs was found in a number of larvae, these effects were not related to temperature and/or CO₂ treatment. We conclude that kingfish larvae are generally vulnerable during organogenesis of the digestive system in their early development, but that this will not be exacerbated by near-future ocean warming and acidification

    Ocean Futures for the World’s Largest Yellowfin Tuna Population Under the Combined Effects of Ocean Warming and Acidification

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    The impacts of climate change are expected to have profound effects on the fisheries of the Pacific Ocean, including its tuna fisheries, the largest globally. This study examined the combined effects of climate change on the yellowfin tuna population using the ecosystem model SEAPODYM. Yellowfin tuna fisheries in the Pacific contribute significantly to the economies and food security of Pacific Island Countries and Territories and Oceania. We use an ensemble of earth climate models to project yellowfin populations under a high greenhouse gas emissions (IPCC RCP8.5) scenario, which includes, the combined effects of a warming ocean, increasing acidification and changing ocean chemistry. Our results suggest that the acidification impact will be smaller in comparison to the ocean warming impact, even in the most extreme ensemble member scenario explored, but will have additional influences on yellowfin tuna population dynamics. An eastward shift in the distribution of yellowfin tuna was observed in the projections in the model ensemble in the absence of explicitly accounting for changes in acidification. The extent of this shift did not substantially differ when the three-acidification induced larval mortality scenarios were included in the ensemble; however, acidification was projected to weaken the magnitude of the increase in abundance in the eastern Pacific. Together with intensive fishing, these potential changes are likely to challenge the global fishing industry as well as the economies and food systems of many small Pacific Island Countries and Territories. The modelling framework applied in this study provides a tool for evaluating such effects and informing policy development

    Self-organized Vortex State in Two-dimensional Dictyostelium Dynamics

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    We present results of experiments on the dynamics of Dictyostelium discoideum in a novel set-up which constraints cell motion to a plane. After aggregation, the amoebae collect into round ''pancake" structures in which the cells rotate around the center of the pancake. This vortex state persists for many hours and we have explicitly verified that the motion is not due to rotating waves of cAMP. To provide an alternative mechanism for the self-organization of the Dictyostelium cells, we have developed a new model of the dynamics of self-propelled deformable objects. In this model, we show that cohesive energy between the cells, together with a coupling between the self-generated propulsive force and the cell's configuration produces a self-organized vortex state. The angular velocity profiles of the experiment and of the model are qualitatively similar. The mechanism for self-organization reported here can possibly explain similar vortex states in other biological systems.Comment: submitted to PRL; revised version dated 3/8/9

    Improvements in forecasting intense rainfall: results from the FRANC (forecasting rainfall exploiting new data assimilation techniques and novel observations of convection) project

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    The FRANC project (Forecasting Rainfall exploiting new data Assimilation techniques and Novel observations of Convection) has researched improvements in numerical weather prediction of convective rainfall via the reduction of initial condition uncertainty. This article provides an overview of the project’s achievements. We highlight new radar techniques: correcting for attenuation of the radar return; correction for beams that are over 90% blocked by trees or towers close to the radar; and direct assimilation of radar reflectivity and refractivity. We discuss the treatment of uncertainty in data assimilation: new methods for estimation of observation uncertainties with novel applications to Doppler radar winds, Atmospheric Motion Vectors, and satellite radiances; a new algorithm for implementation of spatially-correlated observation error statistics in operational data assimilation; and innovative treatment of moist processes in the background error covariance model. We present results indicating a link between the spatial predictability of convection and convective regimes, with potential to allow improved forecast interpretation. The research was carried out as a partnership between University researchers and the Met Office (UK). We discuss the benefits of this approach and the impact of our research, which has helped to improve operational forecasts for convective rainfall event

    Two new rapid SNP-typing methods for classifying Mycobacterium tuberculosis complex into the main phylogenetic lineages

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    There is increasing evidence that strain variation in Mycobacterium tuberculosis complex (MTBC) might influence the outcome of tuberculosis infection and disease. To assess genotype-phenotype associations, phylogenetically robust molecular markers and appropriate genotyping tools are required. Most current genotyping methods for MTBC are based on mobile or repetitive DNA elements. Because these elements are prone to convergent evolution, the corresponding genotyping techniques are suboptimal for phylogenetic studies and strain classification. By contrast, single nucleotide polymorphisms (SNP) are ideal markers for classifying MTBC into phylogenetic lineages, as they exhibit very low degrees of homoplasy. In this study, we developed two complementary SNP-based genotyping methods to classify strains into the six main human-associated lineages of MTBC, the 'Beijing' sublineage, and the clade comprising Mycobacterium bovis and Mycobacterium caprae. Phylogenetically informative SNPs were obtained from 22 MTBC whole-genome sequences. The first assay, referred to as MOL-PCR, is a ligation-dependent PCR with signal detection by fluorescent microspheres and a Luminex flow cytometer, which simultaneously interrogates eight SNPs. The second assay is based on six individual TaqMan real-time PCR assays for singleplex SNP-typing. We compared MOL-PCR and TaqMan results in two panels of clinical MTBC isolates. Both methods agreed fully when assigning 36 well-characterized strains into the main phylogenetic lineages. The sensitivity in allele-calling was 98.6% and 98.8% for MOL-PCR and TaqMan, respectively. Typing of an additional panel of 78 unknown clinical isolates revealed 99.2% and 100% sensitivity in allele-calling, respectively, and 100% agreement in lineage assignment between both methods. While MOL-PCR and TaqMan are both highly sensitive and specific, MOL-PCR is ideal for classification of isolates with no previous information, whereas TaqMan is faster for confirmation. Furthermore, both methods are rapid, flexible and comparably inexpensive

    The influence of age on the female/male ratio of treated incidence rates in depression

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    BACKGROUND: Poor data exist on the influence of psychosocial variables on the female/male ratio of depression because of the small number of cases and the resulting limited numbers of variables available for investigation. For this investigation a large number of first admitted depressed patients (N = 2599) was available which offered the unique opportunity to calculate age specific sex ratios for different marital and employment status categories. METHODS: Age and sex specific population based depression rates were calculated for first ever admissions for single year intervals. Moving averages with interpolated corrections for marginal values in the age distribution were employed. RESULTS: For the total group the female/male ratio of depression showed an inverted U-shape over the life-cycle. This pattern was influenced by the group of married persons, which showed a sex-ratio of 3:1 between the age of 30–50, but ratios of around 1:1 at younger and older ages. For not married persons the female/male ratio was already around 2:1 at the age of 18 and rose to 2.5:1 in mid-life and declined to 1 at around 55. The almost parallel decline of depression rates in employed men and women resulted in a female/male ratio of about 2:1 from age 18 to age 50 and became 1 after the age of 60. The female/male ratio among the not employed was about 1, in mid-life it became negative. CONCLUSIONS: Our analyses show that the gender-gap in first admitted depressed patients is age dependent and that psychosocial factors modify the sex ratio

    Possible Seasonality of Clostridium difficile in Retail Meat, Canada

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    We previously reported Clostridium difficile in 20% of retail meat in Canada, which raised concerns about potential foodborne transmissibility. Here, we studied the genetic diversity of C. difficile in retail meats, using a broad Canadian sampling infrastructure and 3 culture methods. We found 6.1% prevalence and indications of possible seasonality (highest prevalence in winter)
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