A carbon budget for the Amundsen Sea Polynya, Antarctica: Estimating net community production and export in a highly productive polar ecosystem

Polynyas, or recurring areas of seasonally open water surrounded by sea ice, are foci for energy and material transfer between the atmosphere and the polar ocean. They are also climate sensitive, with both sea ice extent and glacial melt influencing their productivity. The Amundsen Sea Polynya (ASP) is the greenest polynya in the Southern Ocean, with summertime chlorophyll a concentrations exceeding 20 μg L−1. During the Amundsen Sea Polynya International Research Expedition (ASPIRE) in austral summer 2010–11, we aimed to determine the fate of this high algal productivity. We collected water column profiles for total dissolved inorganic carbon (DIC) and nutrients, particulate and dissolved organic matter, chlorophyll a, mesozooplankton, and microbial biomass to make a carbon budget for this ecosystem. We also measured primary and secondary production, community respiration rates, vertical particle flux and fecal pellet production and grazing. With observations arranged along a gradient of increasing integrated dissolved inorganic nitrogen drawdown (ΔDIN; 0.027–0.74 mol N m−2), changes in DIC in the upper water column (ranging from 0.2 to 4.7 mol C m−2) and gas exchange (0–1.7 mol C m−2) were combined to estimate early season net community production (sNCP; 0.2–5.9 mol C m−2) and then compared to organic matter inventories to estimate export. From a phytoplankton bloom dominated by Phaeocystis antarctica, a high fraction (up to ∼60%) of sNCP was exported to sub-euphotic depths. Microbial respiration remineralized much of this export in the mid waters. Comparisons to short-term (2–3 days) drifting traps and a year-long moored sediment trap capturing the downward flux confirmed that a relatively high fraction (3–6%) of the export from ∼100 m made it through the mid waters to depth. We discuss the climate-sensitive nature of these carbon fluxes, in light of the changing sea ice cover and melting ice sheets in the region

Seasonal nitrogen uptake and regeneration in the western coastal Arctic

Here, we present the first study to investigate the seasonal importance of amino acid-nitrogen (N) to Arctic near shore microbial communities. We measured primary productivity and the uptake of ammonium, nitrate, urea, and amino acids in two size fractions (\u3e 3 m and approximately 0.7-3 m), as well as ammonium regeneration and nitrification using N-15 and C-13 tracer approaches in the near-shore waters of the Chukchi Sea, during January, April, and August for two consecutive years. At discrete depths, nitrate comprised 46-78% of the total dissolved N pool during January and April but only 2-6% during August. Dissolved organic N (DON) concentrations increased between January and August though the carbon (C):N (mol:mol) of the DON pool declined. Of the substrates tested, amino acids supported the bulk of both N and C nutrition in both size fractions during January and April (ice-covered). Urea generally had the lowest uptake rate under ice-covered conditions; uptake of urea-C was only detectable in August. Though previous Arctic studies focused largely on nitrate, we found nitrate uptake was generally lower than other substrates tested. The sharp decline in nitrate concentration between April and August, however, indicates a drawdown of nitrate during that period. Rates of ammonium uptake were highest in August, when it was the dominant N substrate used. During all sample periods, rates of ammonium regeneration were sufficient to supply ammonium demand. Rates of nitrification varied between sample periods, however, with much higher rates seen in January and April

Microbial Community Response to Terrestrially Derived Dissolved Organic Matter in the Coastal Arctic

Warming at nearly twice the global rate, higher than average air temperatures are the new \u27normal\u27 for Arctic ecosystems. This rise in temperature has triggered hydrological and geochemical changes that increasingly release carbon-rich water into the coastal ocean via increased riverine discharge, coastal erosion, and the thawing of the semipermanent permafrost ubiquitous in the region. To determine the biogeochemical impacts of terrestrially derived dissolved organic matter (tDOM) on marine ecosystems we compared the nutrient stocks and bacterial communities present under ice-covered and ice-free conditions, assessed the lability of Arctic tDOM to coastal microbial communities from the Chukchi Sea, and identified bacterial taxa that respond to rapid increases in tDOM. Once thought to be predominantly refractory, we found that similar to 7% of dissolved organic carbon and similar to 38% of dissolved organic nitrogen from tDOM was bioavailable to receiving marine microbial communities on short 4 - 6 day time scales. The addition of tDOM shifted bacterial community structure toward more copiotrophic taxa and away from more oligotrophic taxa. Although no single order was found to respond universally (positively or negatively) to the tDOM addition, this study identified 20 indicator species as possible sentinels for increased tDOM. These data suggest the true ecological impact of tDOM will be widespread across many bacterial taxa and that shifts in coastal microbial community composition should be anticipated

Evidential Bagging: Combining Heterogeneous Classifiers in the Belief Functions Framework

International audienceIn machine learning, Ensemble Learning methodologies are known to improve predictive accuracy and robustness. They consist in the learning of many classifiers that produce outputs which are finally combined according to different techniques. Bagging, or Bootstrap Aggre-gating, is one of the most famous Ensemble methodologies and is usually applied to the same classification base algorithm, i.e. the same type of classifier is learnt multiple times on bootstrapped versions of the initial learning dataset. In this paper, we propose a bagging methodology that involves different types of classifier. Classifiers' probabilist outputs are used to build mass functions which are further combined within the belief functions framework. Three different ways of building mass functions are proposed; preliminary experiments on benchmark datasets showing the relevancy of the approach are presented

Hydroxytyrosol Protects against Oxidative DNA Damage in Human Breast Cells

Over recent years, several studies have related olive oil ingestion to a low incidence of several diseases, including breast cancer. Hydroxytyrosol and tyrosol are two of the major phenols present in virgin olive oils. Despite the fact that they have been linked to cancer prevention, there is no evidence that clarifies their effect in human breast tumor and non-tumor cells. In the present work, we present hydroxytyrosol and tyrosol’s effects in human breast cell lines. Our results show that hydroxytyrosol acts as a more efficient free radical scavenger than tyrosol, but both fail to affect cell proliferation rates, cell cycle profile or cell apoptosis in human mammary epithelial cells (MCF10A) or breast cancer cells (MDA-MB-231 and MCF7). We found that hydroxytyrosol decreases the intracellular reactive oxygen species (ROS) level in MCF10A cells but not in MCF7 or MDA-MB-231 cells while very high amounts of tyrosol is needed to decrease the ROS level in MCF10A cells. Interestingly, hydroxytyrosol prevents oxidative DNA damage in the three breast cell lines. Therefore, our data suggest that simple phenol hydroxytyrosol could contribute to a lower incidence of breast cancer in populations that consume virgin olive oil due to its antioxidant activity and its protection against oxidative DNA damage in mammary cells

One year outcomes of a mentoring scheme for female academics: a pilot study at the Institute of Psychiatry, King's College London

<p>Abstract</p> <p>Background</p> <p>The professional development of under-represented faculty may be enhanced by mentorship, but we understand very little about the mechanisms by which mentoring brings about change. Our study posed the research question, what are the mechanisms by which mentoring may support professional development in under-represented groups?</p> <p>The study aims to: (i) to pilot a mentoring scheme for female academics; (ii) to compare various health-related and attitudinal measures in mentees at baseline, 6 months, and 1 year into the mentoring relationship and, (iii) to compare pre-mentoring expectations to outcomes at 6 months and 1 year follow-up for mentees and mentors.</p> <p>Methods</p> <p>Female academic mentees were matched 1:1 or 2:1 with more senior academic mentors. Online surveys were conducted to compare health-related and attitudinal measures and expectations of mentoring at baseline with outcomes at 6 months and 1 year using paired t-tests and McNemar's test for matched cohort data.</p> <p>Results</p> <p>N = 46 mentoring pairs, 44 (96%) mentees completed the pre-mentoring survey, 37 (80%) at 6 months and 30 (65%) at 1 year. Job-related well-being (anxiety-contentment), self-esteem and self-efficacy all improved significantly and work-family conflict diminished at 1 year. Highest expectations were career progression (39; 89%), increased confidence (38; 87%), development of networking skills (33; 75%), better time-management (29; 66%) and better work-life balance (28; 64%). For mentees, expectations at baseline were higher than perceived achievements at 6 months or 1 year follow-up.</p> <p>For mentors (N = 39), 36 (92%) completed the pre-mentoring survey, 32 (82%) at 6 months and 28 (72%) at 1 year. Mentors' highest expectations were of satisfaction in seeing people progress (26; 69%), seeing junior staff develop and grow (19; 53%), helping solve problems (18; 50%), helping women advance their careers (18; 50%) and helping remove career obstacles (13; 36%). Overall, gains at 6 months and 1 year exceeded pre-mentoring expectations.</p> <p>Conclusions</p> <p>This uncontrolled pilot study suggests that mentoring can improve aspects of job-related well-being, self-esteem and self-efficacy over 6 months, with further improvements seen after 1 year for female academics. Work-family conflict can also diminish. Despite these gains, mentees' prior expectations were shown to be unrealistically high, but mentors' expectations were exceeded.</p

A school-based program implemented by community providers previously trained for the prevention of eating and weight-related problems in secondary-school adolescents : the MABIC study protocol

Background: The prevention of eating disorders and disordered eating are increasingly recognized as public health priorities. Challenges in this field included moving from efficacy to effectiveness and developing an integrated approach to the prevention of a broad spectrum of eating and weight-related problems. A previous efficacy trial indicated that a universal disordered eating prevention program, based on the social cognitive model, media literacy educational approach and cognitive dissonance theory, reduced risk factors for disordered eating, but it is unclear whether this program has effects under more real-world conditions. The main aim of this effectiveness trial protocol is to test whether this program has effects when incorporating an integrated approach to prevention and when previously-trained community providers implement the intervention. Methods/design: The research design involved a multi-center non-randomized controlled trial with baseline, post and 1-year follow-up measures. Six schools from the city of Sabadell (close to Barcelona) participated in the intervention group, and eleven schools from four towns neighboring Sabadell participated in the control group. A total of 174 girls and 180 boys in the intervention group, and 484 girls and 490 boys in the control group were registered in class lists prior to baseline. A total of 18 community providers, secondary-school class tutors, nurses from the Catalan Government's Health and School Program, and health promotion technicians from Sabadell City Council were trained and delivered the program. Shared risk factors of eating and weight-related problems were assessed as main measures. Discussion: It will be vital for progress in disordered eating prevention to conduct effectiveness trials, which test whether interventions are effective when delivered by community providers under ecologically valid conditions, as opposed to tightly controlled research trials. The MABIC project will provide new contributions in this transition from efficacy to effectiveness and new data about progress in the integrated approach to prevention. Pending the results, the effectiveness trial meets the effectiveness standards set down by the Society for Prevention Research. This study will provide new evidence to improve and enhance disordered eating prevention programs

Guidelines of the Brazilian Association of Studies on Alcohol and Other Drugs (ABEAD) for diagnoses and treatment of psychiatric comorbidity with alcohol and other drugs dependence

Recently, several studies have focused on comorbity psychiatric disorders with alcohol and other substance dependence. The Brazilian Association of Studies on Alcohol and Other Drugs proposed the Brazilian Guidelines project. This study review diagnostic and therapeutic criteria to the most prevalent psychiatric comorbidities. Randomized clinical trials, epidemiological, animal studies and other forms of research are reviewed. The main psychiatric comorbidities are studied based on guidelines adopted by other countries and the literature data resumed. Epidemiological aspects, diagnoses, integrated treatment and service organization, as well as specific psychotherapic and pharmacological treatment are discussed. The Brazilian Association of Studies on Alcohol and Other Drugs Guidelines reassures the importance of adequate diagnoses and treatment regarding alcoholic and drug dependent patients suffering of comorbid psychiatric disorders.O diagnóstico e tratamento de comorbidade psiquiátrica e dependência de álcool e outras substâncias tem sido objeto de inúmeros estudos nos últimos anos. A Associação Brasileira de Estudos do Álcool e Outras Drogas desenvolveu o projeto Diretrizes. Este trabalho visa o desenvolvimento de critérios diagnósticos e terapêuticos atualizados para as comorbidades psiquiátricas mais prevalentes. Ensaios clínicos randomizados, estudos epidemiológicos, com animais e outros estudos são revisados. As principais comorbidades psiquiátricas são estudadas e os dados de literatura resumidos, tendo como referência diretrizes adotadas em outros países. São abordados aspectos epidemiológicos, critérios diagnósticos, tratamento integrado e organização de serviço especializado, assim como especificidades do tratamento psicoterápico e farmacológico. As Diretrizes da Associação Brasileira de Estudos do Álcool e Outras Drogas reforçam a importância da abordagem adequada do dependente químico portador de comorbidade psiquiátrica.Universidade Federal de Santa Catarina Núcleo de PsiquiatriaInstituto de Psiquiatria de Santa CatarinaUniversidade Federal de São Paulo (UNIFESP) Unidade de Pesquisa em Álcool e DrogasSanta Casa de Misericórdia de São Paulo Unidade de Álcool e DrogasUniversidade de São Paulo Faculdade de Medicina Hospital das ClinicasCentro de Atendimento Médico e SocialHospital de Clínicas de Porto AlegreHospital Israelita Albert EinsteinSanta Casa do Rio de Janeiro Setor de Dependência QuímicaUniversidade Gama FilhoUNIFESP, Unidade de Pesquisa em Álcool e DrogasSciEL

Subject specific demands of teaching: Implications for out-of-field teachers

This chapter provides a framework for thinking about the subject-specific nature of teaching in terms of the knowledge, modes of inquiry and discursive practices that delineate one subject from another in the traditional school curriculum. The chapter will explore how these disciplinary traits are translated into teaching as curriculum, knowledge and pedagogy, and how this subject-specificity of teaching is juxtaposed against the more generic aspects of teaching. The chapter explores the idea that if a teacher’s expertise can be situated within a field, then they can also be positioned out-of-field. Implications for teaching out-of-field are discussed in terms of the subject-specific knowledge, processes and skills, and the difficulties associated with teacher practice. English and Australian illustrations of teacher practices from in-field and out-of-field situations are provided, in particular highlighting the demands of moving across subject boundaries. Cross-fertilisation is especially evident when subjects are integrated, therefore, the issues associated with integrated curriculum are discussed where the traditional subject boundaries are being challenged as schools are reorganised to integrate subjects through, for example, STEM teaching, or holistic curriculum designs

Gene Expression Divergence is Coupled to Evolution of DNA Structure in Coding Regions

Sequence changes in coding region and regulatory region of the gene itself (cis) determine most of gene expression divergence between closely related species. But gene expression divergence between yeast species is not correlated with evolution of primary nucleotide sequence. This indicates that other factors in cis direct gene expression divergence. Here, we studied the contribution of DNA three-dimensional structural evolution as cis to gene expression divergence. We found that the evolution of DNA structure in coding regions and gene expression divergence are correlated in yeast. Similar result was also observed between Drosophila species. DNA structure is associated with the binding of chromatin remodelers and histone modifiers to DNA sequences in coding regions, which influence RNA polymerase II occupancy that controls gene expression level. We also found that genes with similar DNA structures are involved in the same biological process and function. These results reveal the previously unappreciated roles of DNA structure as cis-effects in gene expression