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Microphytobenthic extracellular polymeric substances (EPS) in intertidal sediments fuel both generalist and specialist EPS-degrading bacteria

Microphytobenthic biofilms contain high concentrations of carbohydrate-rich extracellular polymeric substances (EPS) that are important in sediment carbon cycling. Field measurements at two locations in the Colne Estuary, U.K., showed that a significant curvilinear relationship explained 50% of the variability in chlorophyll a and EPS content. Estimates of EPS production, based on field data and published rates of production by diatoms, revealed that EPS turnover of 52% to 369% over the tidal cycle was required to account for field standing stocks. We investigated EPS degradation in sediment slurries using purified 13C-EPS produced by the diatom Nitzschia tubicola. Although EPS constituted only 5% of the sediment dissolved organic carbon (DOC) pool, 100% of the added EPS was utilized within 30 h, before decreases in other sediment-carbohydrate fractions and DOC concentrations. A general 13C enrichment of phospholipid fatty acids (PLFAs), representative of Gram-positive and Gram-negative bacteria, occurred within 6 h, with the PLFAs a15:0, i15:0, and 18:1?7c being highly enriched. The diatom PLFA 20:5?3 had relatively low but significant 13C enrichment. Stable isotope probing of 16S ribosomal ribonucleic acid (RNA-SIP) at 30 h revealed 13C-enriched sequences from the diatom genus Navicula; further evidence that diatoms assimilated the EPS, or EPS-breakdown products, from other diatom taxa. RNA-SIP also demonstrated a diverse range of highly 13C-enriched bacterial taxa, including a distinct subset (Alphaproteobacteria and Gammaproteobacteria) found only in the heavily labeled microbial assemblages. Thus, cycling of diatom EPS is rapid, and involves a wide range of microbial taxa, including some apparent specialists

A gauge invariant chiral unitary framework for kaon photo- and electroproduction on the proton

We present a gauge invariant approach to photoproduction of mesons on nucleons within a chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the chiral effective Lagrangian and iterated in a Bethe-Salpeter equation. Within the leading order approximation to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and CBELSA/TAPS are analyzed in the threshold region. The importance of gauge invariance and the precision of various approximations in the interaction kernel utilized in earlier works are discussed.Comment: 23 pages, 13 figs, EPJ A styl

Les fourmis (Hymenoptera, Formicidae) de l’enclos d’acclimatation de Katané de la réserve de faune du Ferlo nord (Sénégal)

Les fourmis (Hymenoptera, Formicidae), de par leur biomasse, et leur diversité spécifique, jouent un rôle fondamental dans les écosystèmes terrestres tropicaux. Néanmoins, elles sont très peu étudiées et mal connues au Sénégal. Pour contribuer à combler cette lacune nous avons étudié le peuplement des fourmis de l’enclos d’acclimatation de Katané, un site se trouvant dans la Réserve de Faune du Ferlo Nord en zone de savane sahélienne (région de Matam, Sénégal). Les fourmis ont été échantillonnées à l’aide de pièges à fosse et par la chasse à vue. La richesse spécifique (S) est de 21 espèces. Les espèces les plus remarquables par leur abondance et leur distribution sont Crematogaster senegalensis, Monomorium areniphilum, Trichomyrmex abyssinicus, Monomorium bicolor, Pheidole andrieui, Brachyponera sennaarensis, Tetramorium angulinode papyri et Tetramorium sericeiventre. Elles appartiennent toutes à la sous-famille des Myrmicinae sauf B. sennaarensis qui est de la sous-famille des Ponerinae. L’indice de fourragement (9,79), l’indice de Shannon (0,95), l’indice d’équitabilité de Piélou (0,77), l’indice de Simpson (0,14) et l’indice de diversité de Simpson (0,86) peuvent être utilisés comme référentiels pour le suivi de l’évolution des habitats de l’enclos et pour les études de l’état de dégradation des habitats dans le Ferlo en général.© 2016 International Formulae Group. All rights reserved.Mots clés: Fourmis, écosystèmes, diversité, abondance, Ferlo nord, SénégalEnglish Title: Ants (Hymenoptera, Formicidae) of the acclimatization enclosure of Katane in the north Ferlo wildlife reserve (Senegal)English AbstractAnts (Hymenoptera, Formicidae), by their biomass and species diversity, play a fundamental role in the terrestrial ecosystems of the tropical area. Nevertheless, they are very little studied and poorly known in Senegal. To fill this gap we have chosen to study them in the acclimatization enclosure of Katane in the north Ferlo Reserve Wildlife situated in the Sahel savanna in Matam region (Senegal). They were sampled using pitfall traps and hand collecting. Species richness (S) is 21 species. The most remarkable for their abundances and distributions are Crematogaster senegalensis, Monomorium areniphilum, Trichomyrmex abyssinicus, Monomorium bicolor, Pheidole andrieui, Brachyponera sennaarensis, Tetramorium angulinode papyri and Tetramorium sericeiventre. They all belong to the subfamily Myrmicinae except B. sennaarensis which belongs to the subfamily Ponerinae. The foraging index (9.79), the Shannon index (0.95), the index of Pielou equitability (0.77), the Simpson index (0.14) and the Simpson's index diversity (0.86) can be used as reference for monitoring the biotopes evolution in the enclosure of Katané and for the studies of land degradation in the Ferlo in general.© 2016 International Formulae Group. All rights reserved.Keywords: Ants, ecosystems, diversity, abundance, northern Ferlo, Senega

Algorithms for the self-optimisation of chemical reactions

Self-optimising chemical systems have experienced a growing momentum in recent years, with the evolution of self-optimising platforms leading to their application for reaction screening and chemical synthesis. With the desire for improved process sustainability, self-optimisation provides a cheaper, faster and greener approach to the chemical development process. The use of such platforms aims to enhance the capabilities of the researcher by removing the need for labor-intensive experimentation, allowing them to focus on more challenging tasks. The establishment of these systems have enabled opportunities for self-optimising platforms to become a key element of a laboratory’s repertoire. To enable the wider adoption of self-optimising chemical platforms, this review summarises the history of algorithmic usage in chemical reaction self-optimisation, detailing the functionality of the algorithms and their applications in a way that is accessible for chemists and highlights opportunities for the further exploitation of algorithms in chemical synthesis moving forward

Isocyanide based multicomponent reactions of oxazolidines and related systems

N-Alkyloxazolidines react in a multicomponent reaction with carboxylic acids and isocyanides to give N-acyloxyethylamino acid amides. The previously reported reaction conditions were improved using a design of experiments approach (DoE). Under the optimised conditions, good yields of the N-acyloxyethylamino acid amide products are obtained both via a three- or four-component approach from N-alkylethanolamines, aldehydes/ketones, isocyanides and carboxylic acids. The reaction of oxazolidines without a nitrogen substituent was found to give either the expected Ugi products or the N-acyloxyethylamino acid amides depending on the choice of reaction conditions. Optimised reaction conditions were also developed for the ring-expansion of oxazolidines to morpholin-2-ones via reaction with an isocyanide followed by hydrolysis. The mechanistic pathway of the multicomponent reaction was briefly investigated using an O-18 labelling experiment. The carboxylic acid component can be replaced by a range of other acidic nucleophiles including thiobenzoic acid, thiophenol or 5-phenyltetrazole, which are incorporated via an alternative pathway. These latter reactions can also be applied to 2-aminotetrahydrofurans, 2-aminotetrahydropyrans or 4-hydroxybut-2-one, further extending the structural diversity of the multicomponent reaction products. (C) 2010 Elsevier Ltd. All rights reserved

The molecular basis of socially mediated phenotypic plasticity in a eusocial paper wasp

Phenotypic plasticity, the ability to produce multiple phenotypes from a single genotype, represents an excellent model with which to examine the relationship between gene expression and phenotypes. Analyses of the molecular foundations of phenotypic plasticity are challenging, however, especially in the case of complex social phenotypes. Here we apply a machine learning approach to tackle this challenge by analyzing individual-level gene expression profiles of Polistes dominula paper wasps following the loss of a queen. We find that caste-associated gene expression profiles respond strongly to queen loss, and that this change is partly explained by attributes such as age but occurs even in individuals that appear phenotypically unaffected. These results demonstrate that large changes in gene expression may occur in the absence of outwardly detectable phenotypic changes, resulting here in a socially mediated de-differentiation of individuals at the transcriptomic level but not at the levels of ovarian development or behavior

Multiple sclerosis susceptibility alleles in African Americans.

Multiple sclerosis (MS) is an autoimmune demyelinating disease characterized by complex genetics and multifaceted gene-environment interactions. Compared to whites, African Americans have a lower risk for developing MS, but African Americans with MS have a greater risk of disability. These differences between African Americans and whites may represent differences in genetic susceptibility and/or environmental factors. SNPs from 12 candidate genes have recently been identified and validated with MS risk in white populations. We performed a replication study using 918 cases and 656 unrelated controls to test whether these candidate genes are also associated with MS risk in African Americans. CD6, CLEC16a, EVI5, GPC5, and TYK2 contained SNPs that are associated with MS risk in the African American data set. EVI5 showed the strongest association outside the major histocompatibility complex (rs10735781, OR=1.233, 95% CI=1.06-1.43, P-value=0.006). In addition, RGS1 seems to affect age of onset whereas TNFRSF1A seems to be associated with disease progression. None of the tested variants showed results that were statistically inconsistent with the effects established in whites. The results are consistent with shared disease genetic mechanisms among individuals of European and African ancestry

An Assessment of Funding and Other Capacity Needs for Health Equity Programming Within State-Level Chronic Disease Programs

Background: Chronic diseases are an important contributor to morbidity and mortality among racial/ethnic minority, low-income, and other under-resourced populations. Given that state health departments (and their chronic disease programs) play a significant role in providing population and preventive health services, their capacity to promote health equity is an important consideration in national efforts to address chronic diseases. The purpose of this study was to examine capacity needs of state chronic disease programs with respect to promoting health equity. Methods: In 2015, the National Association of Chronic Disease Directors (NACDD) conducted a survey of its members that work within a state chronic disease division (CDD) or the larger state health department. The survey was structured to provide information on major funding sources for chronic diseases, the extent to which key funders required a focus on health equity, dedicated staffing for health equity, and training and technical assistance needs of practitioners to support health equity integration in chronic disease programming. All data were analyzed using SPSS 19.0. Findings: A total of 147 chronic disease directors and practitioners responded to the survey from 43 states, the District of Columbia and three of the U.S. Affiliated Territories and Commonwealths. Forty-two percent (N=25) of the 59 directors of state, territorial and tribal chronic disease programs at the time of the study responded. Only 52% of respondents believed their CDD adequately addressed health inequities. Among the 70 respondents who did not know or did not believe their health departments adequately addressed health inequities, barriers identified include insufficient funding (62%), inadequate training (54%), and health inequities not being a priority (22%). Respondents also identified opportunities to strengthen funding requirements to address health disparities Conclusions: Overall, the data highlight some opportunities to enhance the capacity of state CDDs to promote health equity, such as through more direct funding requirements for health equity integration, staff training, increased funding, and specialized technical assistance. Because the response rate was less than 100%, we cannot generalize the findings to every state chronic disease program. However, the responses are relatable to their collective experience