821 research outputs found

    Estimation of spatially correlated random scaling factors based on Markov random field priors

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    Multiplicative random effects allow for cluster-specific scaling of covariate effects. In many applications with spatial clustering, however, the random effects additionally show some geographical pattern, which usually can not sufficiently be captured with existing estimation techniques. Relying on Markov random fields, we present a fully Bayesian inference procedure for spatially correlated scaling factors. The estimation is based on highly efficient Markov Chain Monte Carlo (MCMC) algorithms and is smoothly incorporated into the framework of distributional regression. We run a comprehensive simulation study for different response distributions to examine the statistical properties of our approach. We also compare our results to those of a general estimation procedure for independent random scaling factors. Furthermore, we apply the method to German real estate data and show that exploiting the spatial correlation of the scaling factors further improves the performance of the model

    Environmental Correlates of Hermatypic Coral (Montastrea annularis) Growth on the East Flower Gardens Bank, Northwest Gulf of Mexico

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    Time series of annual linear growth increments from 12 Montastrea annularis (E. and S.) collected at the East Flower Gardens Bank reef in the northwestern Gulf of Mexico have a common pattern. This is best expressed in an index master chronology (average by year of the annual percentage deviations from the mean of each coral.) Comparisons with time series of environmental data indicate that coral extension rates vary positively with seasonal (February through May - 4 months) surface water temperature and negatively with annual discharge of the Atchafalaya River. We propose that secular variations of water temperature and other parameters are the major long term controls of coral growth in the area. Our data do not support the view that sinking of the Flower Gardens reef, caused by catastrophic collapse of the underlying substrate, has been a prime influence on the corals

    Biozonation of Deep-Water Lithoherms and Associated Hardgrounds in the Northeastern Straits of Florida

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    Elongated carbonate mounds ( lithoherms ) oriented parallel to prevailing northerly bottom currents at moderate depths (500-700 m) along the western margin of the Little Bahama Bank exhibit a consistent faunal zonation characterized by attached, suspension-feeding invertebrates. The four most abundant macroepibenthic groups (alcyonarians, crinoids, sponges and stylasterid hydrocorals) dominate all hard substrates examined except upcurrent ends and crests of lithoherms. We recognize three faunal zones on these mounds: a Coral Zone (Lophelia prolifera) restricted to the upcurrent end; a Zoanthid Zone (?Gerardia sp.) along upcurrent crests, and a Crinoid/Alcyonarian Zone along lithoherm flanks and downstream crests. Taxa characteristic of the latter also occur on surrounding, low-relief hardgrounds but are accompanied by additional taxa usually absent from mounds. Intervening unconsolidated sediment is largely barren. Biozonation appears chiefly dependent on current flow regime and secondarily on substrate. The observed zonation occurs over a much smaller areal scale than previously reported for deep-water (non-hydrothermal) hard bottoms. Abrupt, small-scale faunal zonation can no longer automatically be considered as evidence of a shallow-water environment in interpreting fossil assemblages

    Lessons Learned from Two Case Studies in Higher Education

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    As places where future citizens are educated, knowledge is (co-)produced and societal developments are critically reflected, higher education institutions (HEIs) can play a key role in addressing sustainability challenges. In order to accelerate mutual learning, shared problem understanding, and joint development of sustainable solutions, interinstitutional exchange and collaboration between HEIs is crucial. However, little research to date has focused on institutional HEI networks in the field of sustainability. More specifically, we still understand little about the concrete development, implementation, and adaptation of such networks. This article explores early-stage HEI networks for sustainability from a conceptual and empirical stance in order to develop a framework that facilitates structured descriptions of these networks, as well as to foster cross-HEI learning on their effective performance. It therefore combines insights from an explorative literature review, two case studies and an interactive workshop at the ISCN Conference 2018. As results, we first suggest an analytical framework to facilitate a systematic characterization of HEI networks. Second, by applying the framework to the two case studies, we present and discuss lessons learned on how a single HEI can contribute to establishing a network and how it can utilize its network membership effectively to strengthen its efforts for sustainability

    Stat6-Dependent Inhibition of Mincle Expression in Mouse and Human Antigen-Presenting Cells by the Th2 Cytokine IL-4

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    The C-type lectin receptors (CLR) Mincle, Mcl and Dectin-2 bind mycobacterial and fungal cell wall glycolipids and carbohydrates. Recently, we described that expression of these CLR is down-regulated during differentiation of human monocytes to dendritic cells (DC) in the presence of GM-CSF and IL-4. Here, we demonstrate that the Th2 cytokine IL-4 specifically inhibits expression of Mincle, Mcl and Dectin-2in human APC. This inhibitory effect of IL-4 was observed across species, as murine macrophages and DC treated with IL-4 also down-regulated these receptors. IL-4 blocked up-regulation of Mincle and Mcl mRNA expression and cell surface protein by murine macrophages in response to the Mincle ligand Trehalose-6,6-dibehenate (TDB), whereas the TLR4 ligand LPS overcame inhibition by IL-4. Functionally, down-regulation of Mincle expression by IL-4 was accompanied by reduced cytokine production upon stimulation with TDB. These inhibitory effects of IL-4 were dependent on the transcription factor Stat6. Together, our results show that the key Th2 cytokine IL-4 exerts a negative effect on the expression of Mincle and other Dectin-2 cluster CLR in mouse and human macrophages and DC, which may render these sentinel cells less vigilant for sensing mycobacterial and fungal ligands

    Sleep During Pregnancy: The nuMoM2b Pregnancy and Sleep Duration and Continuity Study

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    Study Objectives: To characterize sleep duration, timing and continuity measures in pregnancy and their association with key demographic variables. Methods: Multisite prospective cohort study. Women enrolled in the nuMoM2b study (nulliparous women with a singleton gestation) were recruited at the second study visit (16-21 weeks of gestation) to participate in the Sleep Duration and Continuity substudy. Women <18 years of age or with pregestational diabetes or chronic hypertension were excluded from participation. Women wore a wrist activity monitor and completed a sleep log for 7 consecutive days. Time in bed, sleep duration, fragmentation index, sleep efficiency, wake after sleep onset, and sleep midpoint were averaged across valid primary sleep periods for each participant. Results: Valid data were available from 782 women with mean age of 27.3 (5.5) years. Median sleep duration was 7.4 hours. Approximately 27.9% of women had a sleep duration of 9 hours. In multivariable models including age, race/ethnicity, body mass index, insurance status, and recent smoking history, sleep duration was significantly associated with race/ethnicity and insurance status, while time in bed was only associated with insurance status. Sleep continuity measures and sleep midpoint were significantly associated with all covariates in the model, with the exception of age for fragmentation index and smoking for wake after sleep onset. Conclusions: Our results demonstrate the relationship between sleep and important demographic characteristics during pregnancy
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