Abstract
A multiphysics and a stochastic kinetic-energy backscatter scheme are employed to represent model uncertainty in a mesoscale ensemble prediction system using the Weather Research and ...Forecasting model. Both model-error schemes lead to significant improvements over the control ensemble system that is simply a downscaled global ensemble forecast with the same physics for each ensemble member. The improvements are evident in verification against both observations and analyses, but different in some details. Overall the stochastic kinetic-energy backscatter scheme outperforms the multiphysics scheme, except near the surface. Best results are obtained when both schemes are used simultaneously, indicating that the model error can best be captured by a combination of multiple schemes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
There is considerable interest in understanding further the factors that increase the risk of post-traumatic stress disorder (PTSD) for military personnel. This study aimed to investigate the ...relative contribution of demographic variables; childhood adversity; the nature of exposure to traumatic events during deployment; appraisal of these experiences; and home-coming experiences in relation to the prevalence of PTSD 'caseness' as measured by a score of 50 on the PTSD Checklist (PCL) in UK Armed Forces personnel who have been deployed in Iraq since 2003.
Data were drawn from the first stage of a retrospective cohort study comparing UK military personnel who were deployed to the 2003 Iraq War with personnel serving in the UK Armed Forces on 31 March 2003 but who were not deployed to the initial phase of war fighting. Participants were randomly selected and invited to participate. The response rate was 61%. We have limited these analyses to 4762 regular service individuals who responded to the survey and who have been deployed in Iraq since 2003.
Post-traumatic stress symptoms were associated with lower rank, being unmarried, having low educational attainment and a history of childhood adversity. Exposure to potentially traumatizing events, in particular being deployed to a 'forward' area in close contact with the enemy, was associated with post-traumatic stress symptoms. Appraisals of the experience as involving threat to one's own life and a perception that work in theatre was above an individual's trade and experience were strongly associated with post-traumatic stress symptoms. Low morale and poor social support within the unit and non-receipt of a home-coming brief (psycho-education) were associated with greater risk of post-traumatic stress symptoms.
Personal appraisal of threat to life during the trauma emerged as the most important predictor of post-traumatic stress symptoms. These results also raise the possibility that there are important modifiable occupational factors such as unit morale, leadership, preparing combatants for their role in theatre which may influence an individual's risk of post-traumatic stress symptoms. Therefore interventions focused on systematic preparation of personnel for the extreme stress of combat may help to lessen the psychological impact of deployment.
This study relies on IPUMS samples of the 1850, 1860, 1870, and 1880 censuses, aggregate census data, and the timing of state laws criminalizing abortion to construct regional estimates of marital ...fertility in the United States and estimate correlates of marital fertility. The results show a significant lag between the onset of marital fertility decline in the nation's northeastern census divisions and its onset in western and southern census divisions. Empirical models indicate the presence of cultural, economic, and legal impediments to the diffusion of marital fertility control and illustrate the need for more inclusive models of fertility decline.
Children require a large amount of time, effort, and resources to raise. Physical help, financial contributions, medical care, and other types of assistance from kin and social network members allow ...couples to space births closer together while maintaining or increasing child survival. We examine the impact of kin availability on couples' reproductive success in the early twentieth-century United States with a panel data set of over 3.1 million couples linked between the 1900 and 1910 U.S. censuses. Our results indicate that kin proximity outside the household was positively associated with fertility, child survival, and net reproduction, and suggest that declining kin availability was an important contributing factor to the fertility transition in the United States. We also find important differences between maternal and paternal kin inside the household—including higher fertility among women residing with their mother-in-law than among those residing with their mother—that support hypotheses related to the contrasting motivations and concerns of parents and parents-in-law.
A growing body of research considers racial residential segregation to be a form of systemic racism and a fundamental cause of persistent racial disparities in health and mortality. Historical ...research examining the impact of segregation on health and mortality, however, is limited to a few studies with poor data and inconsistent results. In this study, we examine the association between racial residential segregation and child mortality in the South at the turn of the 20th century. We rely on the new IPUMS 1900 and 1910 complete‐count databases to estimate child mortality in the 5 years before each census and construct segregation measures at the census enumeration district (ED), the lowest level of geography consistently available in the census. We calculate the proportion of households headed by Black individuals in each ED, and the Sequence Index of Segregation (SIS), which is based on the racial sequencing of household heads within each district. We construct models of child mortality for rural and urban areas, controlling for a wide variety of demographic and socioeconomic variables. The results indicate that proportion Black and SIS were strongly and positively associated with the mortality of Black children in most models and in both rural and urban areas. Proportion Black was also positively but more moderately correlated with the mortality of White children, while SIS was not correlated or negatively correlated. These results suggest that racial segregation was a long‐standing fundamental cause of race disparities in health and mortality in the United States.
Sepsis, a life-threatening systemic inflammatory response syndrome induced by infection, is widely studied using laboratory animal models. While cecal-ligation and puncture (CLP) is considered the ...gold standard model for sepsis research, it may not be preferable for experiments comparing animals of different size or under different dietary regimens. By comparing cecum size, shape, and cecal content characteristics in mice under different experimental conditions (aging, diabetes, pancreatitis), we show that cecum variability could be problematic for some CLP experiments. The cecal slurry (CS) injection model, in which the cecal contents of a laboratory animal are injected intraperitoneally to other animals, is an alternative method for inducing polymicrobial sepsis; however, the CS must be freshly prepared under conventional protocols, which is a major disadvantage with respect to reproducibility and convenience. The objective of this study was to develop an improved CS preparation protocol that allows for long-term storage of CS with reproducible results. Using our new CS preparation protocol we found that bacterial viability is maintained for at least 6 months when the CS is prepared in 15% glycerol-PBS and stored at -80°C. To test sepsis-inducing efficacy of stored CS stocks, various amounts of CS were injected to young (4-6 months old), middle-aged (12-14 months old), and aged (24-26 months old) male C57BL/6 mice. Dose- and age-dependent mortality was observed with high reproducibility. Circulating bacteria levels strongly correlated with mortality suggesting an infection-mediated death. Further, injection with heat-inactivated CS resulted in acute hypothermia without mortality, indicating that CS-mediated death is not due to endotoxic shock. This new CS preparation protocol results in CS stocks which are durable for freezing preservation without loss of bacterial viability, allowing experiments to be performed more conveniently and with higher reproducibility than before.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Four model-error schemes for probabilistic forecasts over the contiguous United States with the WRF-ARW mesoscale ensemble system are evaluated in regard to performance. Including a model-error ...representation leads to significant increases in forecast skill near the surface as measured by the Brier score. Combining multiple model-error schemes results in the best-performing ensemble systems, indicating that current model error is still too complex to be represented by a single scheme alone. To understand the reasons for the improved performance, it is examined whether model-error representations increase skill merely by increasing the reliability and reducing the bias-which could also be achieved by postprocessing-or if they have additional benefits. Removing the bias results overall in the largest skill improvement. Forecasts with model-error schemes continue to have better skill than without, indicating that their benefit goes beyond bias reduction. Decomposing the Brier score into its components reveals that, in addition to the spread-sensitive reliability, the resolution component is significantly improved. This indicates that the benefits of including a model-error representation go beyond increasing reliability. This is further substantiated when all forecasts are calibrated to have similar spread. The calibrated ensembles with model-error schemes consistently outperform the calibrated control ensemble. Including a model-error representation remains beneficial even if the ensemble systems are calibrated and/or debiased. This suggests that the merits of model-error representations go beyond increasing spread and removing the mean error and can account for certain aspects of structural model uncertainty.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
To date, most studies to identify biomarkers associated with response to the anti-interleukin 5 agent, mepolizumab, and to the anti-immunoglobulin E agent, omalizumab have focused on clinically ...available biomarkers, such as the peripheral blood eosinophil counts (BEC) and total immunoglobulin E (IgE). However, these biomarkers often have low predictive accuracy, with many patients with eosinophilic or allergic asthma failing to demonstrate clinical response to mepolizumab or omalizumab respectively. In this study, we evaluated the association of baseline pre-biologic plasma levels of 26 cytokines and chemokines, including T-helper 1 (Th1)-, Th2-, Th17-related cytokines, and their ratios with subsequent clinical response to mepolizumab or omalizumab. We defined clinical response as a reduction in the baseline annual exacerbation rate by half or more over the one-year period following initiation of the biologic. Baseline levels of plasma IL-13 were differentially elevated in responders versus non-responders to mepolizumab and plasma CXCL10 levels were differentially elevated in responders to omalizumab. The ratio of IL-13/TNF-α had the best sensitivity and specificity in predicting response to mepolizumab and CXCL10/CCL17 to omalizumab, and these performed better as predictive biomarkers of response than BEC and IgE. Cytokines and chemokines associated with airway eosinophilia, allergic inflammation, or Th2 inflammation, such as IL-13 and CXCL10, may be better predictors of clinical response to mepolizumab and omalizumab, than IL-5 or IgE, the targets of mepolizumab and omalizumab.
This research note describes the growth of the slave population in the United States and develops several new measures of its size and growth, including an estimate of the total number of slaves who ...ever lived in the United States. Estimates of the number of births and slave imports are provided in ten-year increments between 1619 and 1860 and in one-year increments between 1861 and 1865. The results highlight the importance of natural increase to the rapid growth of the U.S. slave population and indicate that approximately 10 million slaves lived in the United States, where they contributed 410 billion hours of labor. A concluding discussion highlights a few descriptive statistics historians might find useful, including the cumulative number of slaves who lived in the United States by decade and the proportion of slaves who were living at various moments in U.S. history, including shortly after the ratification of the Constitution in 1788 and at the start of the American Civil War in 1861.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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