Metal-macrofauna interactions determine microbial community structure and function in copper contaminated sediments

Peer reviewedPublisher PD

Murine Dishevelled 3 Functions in Redundant Pathways with Dishevelled 1 and 2 in Normal Cardiac Outflow Tract, Cochlea, and Neural Tube Development

Dishevelled (Dvl) proteins are important signaling components of both the canonical β-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3−/− mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3−/− and LtapLp/+ mutants, Dvl3+/−;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant

Learning to teach data journalism: Innovation, influence and constraints

Journalism education has tended to respond slowly to developments in digital journalism, such as data journalism, despite or because of close links with the industry. This paper examines the obstacles to innovation in journalism education with particular reference to data journalism, drawing on the literature, a review of stakeholders and course documents, and the author’s reflections on developing a data journalism module as part of a new MA programme. It highlights the complexities linked to the particular demands of data journalism, and identifies critical issues around student satisfaction; reputation and job/career outcomes; relevance, currency and appeal; programme management; and coherence. Rather than holding it back, more specialized socialization could assist journalism education to innovate effectively, the author suggests

Murine Dishevelled 3 Functions in Redundant Pathways with Dishevelled 1 and 2 in Normal Cardiac Outflow Tract, Cochlea, and Neural Tube Development

Dishevelled (Dvl) proteins are important signaling components of both the canonical β-catenin/Wnt pathway, which controls cell proliferation and patterning, and the planar cell polarity (PCP) pathway, which coordinates cell polarity within a sheet of cells and also directs convergent extension cell (CE) movements that produce narrowing and elongation of the tissue. Three mammalian Dvl genes have been identified and the developmental roles of Dvl1 and Dvl2 were previously determined. Here, we identify the functions of Dvl3 in development and provide evidence of functional redundancy among the three murine Dvls. Dvl3−/− mice died perinatally with cardiac outflow tract abnormalities, including double outlet right ventricle and persistent truncus arteriosis. These mutants also displayed a misorientated stereocilia in the organ of Corti, a phenotype that was enhanced with the additional loss of a single allele of the PCP component Vangl2/Ltap (LtapLp/+). Although neurulation appeared normal in both Dvl3−/− and LtapLp/+ mutants, Dvl3+/−;LtapLp/+ combined mutants displayed incomplete neural tube closure. Importantly, we show that many of the roles of Dvl3 are also shared by Dvl1 and Dvl2. More severe phenotypes were observed in Dvl3 mutants with the deficiency of another Dvl, and increasing Dvl dosage genetically with Dvl transgenes demonstrated the ability of Dvls to compensate for each other to enable normal development. Interestingly, global canonical Wnt signaling appeared largely unaffected in the double Dvl mutants, suggesting that low Dvl levels are sufficient for functional canonical Wnt signals. In summary, we demonstrate that Dvl3 is required for cardiac outflow tract development and describe its importance in the PCP pathway during neurulation and cochlea development. Finally, we establish several developmental processes in which the three Dvls are functionally redundant

Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine.

OBJECTIVE: Circulatory shock is a life-threatening syndrome resulting in multiorgan failure and a high mortality rate. The aim of this consensus is to provide support to the bedside clinician regarding the diagnosis, management and monitoring of shock. METHODS: The European Society of Intensive Care Medicine invited 12 experts to form a Task Force to update a previous consensus (Antonelli et al.: Intensive Care Med 33:575-590, 2007). The same five questions addressed in the earlier consensus were used as the outline for the literature search and review, with the aim of the Task Force to produce statements based on the available literature and evidence. These questions were: (1) What are the epidemiologic and pathophysiologic features of shock in the intensive care unit ? (2) Should we monitor preload and fluid responsiveness in shock ? (3) How and when should we monitor stroke volume or cardiac output in shock ? (4) What markers of the regional and microcirculation can be monitored, and how can cellular function be assessed in shock ? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock ? Four types of statements were used: definition, recommendation, best practice and statement of fact. RESULTS: Forty-four statements were made. The main new statements include: (1) statements on individualizing blood pressure targets; (2) statements on the assessment and prediction of fluid responsiveness; (3) statements on the use of echocardiography and hemodynamic monitoring. CONCLUSIONS: This consensus provides 44 statements that can be used at the bedside to diagnose, treat and monitor patients with shock

Strategies for Diagnosis and Treatment of Suspected Leptospirosis: A Cost-Benefit Analysis

Symptoms and signs of leptospirosis are non-specific. A number of diagnostic tests for leptospirosis are available. We compared the cost-benefit of 5 management strategies: 1) no patients tested or given antibiotic treatment; 2) all patients given empirical doxycycline treatment; patients given doxycycline when a patient is tested positive for leptospirosis using: 3) lateral flow; 4) MCAT; 5) latex test. Outcomes were measured in duration of fever which is then converted to productivity losses to capture the full economic costs. Empirical doxycycline treatment was found to be the most efficient strategy, being both the least costly alternative and the one that resulted in the lowest average duration of fever. The significantly higher relative cost of using a diagnostic test as compared with presumptive treatment, and the limited sensitivity of all the diagnostic tests implied that only the latex test could be considered cost-effective when compared with the no-antibiotic-treatment option, and that all three tests were still inferior to empirical treatment

Early Mortality and AIDS Progression Despite High Initial Antiretroviral Therapy Adherence and Virologic Suppression in Botswana

Background Adverse outcomes occurring early after antiretroviral therapy (ART) initiation are common in sub-Saharan Africa, despite reports of high levels of ART adherence in this setting. We sought to determine the relationship between very early ART adherence and early adverse outcomes in HIV-infected adults in Botswana. Methods This prospective cohort study of 402 ART-naïve, HIV-infected adults initiating ART at a public HIV clinic in Gaborone, Botswana evaluated the relationship between suboptimal early ART adherence and HIV treatment outcomes in the initial months after ART initiation. Early adherence during the interval between initial ART dispensation and first ART refill was calculated using pill counts. In the primary analysis patients not returning to refill and those with adherence \u3c0.95 were considered to have suboptimal early adherence. The primary outcome was death or loss to follow-up during the first 6 months of ART; a secondary composite outcome included the primary outcome plus incident opportunistic illness (OIs) and virologic failure. We also calculated the percent of early adverse outcomes theoretically attributable to suboptimal early adherence using the population attributable risk percent (PAR%). Results Suboptimal early adherence was independently associated with loss to follow-up and death (adjusted OR 2.3, 95% CI 1.1–4.8) and with the secondary composite outcome including incident OIs and virologic failure (adjusted OR 2.6, 95% CI 1.4–4.7). However, of those with early adverse outcomes, less than one-third had suboptimal adherence and approximately two-thirds achieved virologic suppression. The PAR% relating suboptimal early adherence and primary and secondary outcomes were 14.7% and 17.7%, respectively. Conclusions Suboptimal early adherence was associated with poor outcomes, but most early adverse outcomes occurred in patients with optimal early adherence. Clinical care and research efforts should focus on understanding early adverse outcomes that occur despite optimal adherence

Undergraduate medical research: the student perspective

Background: Research training is essential in a modern undergraduate medical curriculum. Our evaluation aimed to (a) gauge students’ awareness of research activities, (b) compare students’ perceptions of their transferable and research-specific skills competencies, (c) determine students’ motivation for research and (d) obtain students’ personal views on doing research. Methods: Undergraduate medical students (N=317) completed a research skills questionnaire developed by the Centre for Excellence in Teaching and Learning in Applied Undergraduate Research Skills (CETL-AURS) at Reading University. The questionnaire assessed students’ transferable skills, research-specific skills (e.g., study design, data collection and data analysis), research experience and attitude and motivation towards doing research. Results: The majority of students are motivated to pursue research. Graduate entrants and male students appear to be the most confident regarding their research skills competencies. Although all students recognise the role of research in medical practice, many are unaware of the medical research activities or successes within their university. Of those who report no interest in a career incorporating research, a common perception was that researchers are isolated from patients and clinical practice. Discussion: Students have a narrow definition of research and what it entails. An explanation for why research competence does not align more closely with research motivation is derived from students’ lack of understanding of the concept of translational research, as well as a lack of awareness of the research activity being undertaken by their teachers and mentors. We plan to address this with specific research awareness initiatives

Wnt5a Regulates Ventral Midbrain Morphogenesis and the Development of A9–A10 Dopaminergic Cells In Vivo

Wnt5a is a morphogen that activates the Wnt/planar cell polarity (PCP) pathway and serves multiple functions during development. PCP signaling controls the orientation of cells within an epithelial plane as well as convergent extension (CE) movements. Wnt5a was previously reported to promote differentiation of A9–10 dopaminergic (DA) precursors in vitro. However, the signaling mechanism in DA cells and the function of Wnt5a during midbrain development in vivo remains unclear. We hereby report that Wnt5a activated the GTPase Rac1 in DA cells and that Rac1 inhibitors blocked the Wnt5a-induced DA neuron differentiation of ventral midbrain (VM) precursor cultures, linking Wnt5a-induced differentiation with a known effector of Wnt/PCP signaling. In vivo, Wnt5a was expressed throughout the VM at embryonic day (E)9.5, and was restricted to the VM floor and basal plate by E11.5–E13.5. Analysis of Wnt5a−/− mice revealed a transient increase in progenitor proliferation at E11.5, and a precociously induced NR4A2+ (Nurr1) precursor pool at E12.5. The excess NR4A2+ precursors remained undifferentiated until E14.5, when a transient 25% increase in DA neurons was detected. Wnt5a−/− mice also displayed a defect in (mid)brain morphogenesis, including an impairment in midbrain elongation and a rounded ventricular cavity. Interestingly, these alterations affected mostly cells in the DA lineage. The ventral Sonic hedgehog-expressing domain was broadened and flattened, a typical CE phenotype, and the domains occupied by Ngn2+ DA progenitors, NR4A2+ DA precursors and TH+ DA neurons were rostrocaudally reduced and laterally expanded. In summary, we hereby describe a Wnt5a regulation of Wnt/PCP signaling in the DA lineage and provide evidence for multiple functions of Wnt5a in the VM in vivo, including the regulation of VM morphogenesis, DA progenitor cell division, and differentiation of NR4A2+ DA precursors

Intermediate predator naïveté and sex-skewed vulnerability predict the impact of an invasive higher predator

The spread of invasive species continues to reduce biodiversity across all regions and habitat types globally. However, invader impact prediction can be nebulous, and approaches often fail to integrate coupled direct and indirect invader effects. Here, we examine the ecological impacts of an invasive higher predator on lower trophic groups, further developing methodologies to more holistically quantify invader impact. We employ functional response (FR, resource use under different densities) and prey switching experiments to examine the trait- and density-mediated impacts of the invasive mosquitofish Gambusia affinis on an endemic intermediate predator Lovenula raynerae (Copepoda). Lovenula raynerae effectively consumed larval mosquitoes, but was naïve to mosquitofish cues, with attack rates and handling times of the intermediate predator unaffected by mosquitofish cue-treated water. Mosquitofish did not switch between male and female prey, consistently displaying a strong preference for female copepods. We thus demonstrate a lack of risk-reduction activity in the presence of invasive fish by L. raynerae and, in turn, high susceptibility of such intermediate trophic groups to invader impact. Further, we show that mosquitofish demonstrate sex-skewed predator selectivity towards intermediate predators of mosquito larvae, which may affect predator population demographics and, perversely, increase disease vector proliferations. We advocate the utility of FRs and prey switching combined to holistically quantify invasive species impact potential on native organisms at multiple trophic levels