An approach for particle sinking velocity measurements in the 3–400 μm size range and considerations on the effect of temperature on sinking rates

The flux of organic particles below the mixed layer is one major pathway of carbon from the surface into the deep ocean. The magnitude of this export flux depends on two major processes—remineralization rates and sinking velocities. Here, we present an efficient method to measure sinking velocities of particles in the size range from approximately 3–400 μm by means of video microscopy (FlowCAM®). The method allows rapid measurement and automated analysis of mixed samples and was tested with polystyrene beads, different phytoplankton species, and sediment trap material. Sinking velocities of polystyrene beads were close to theoretical values calculated from Stokes’ Law. Sinking velocities of the investigated phytoplankton species were in reasonable agreement with published literature values and sinking velocities of material collected in sediment trap increased with particle size. Temperature had a strong effect on sinking velocities due to its influence on seawater viscosity and density. An increase in 9 °C led to a measured increase in sinking velocities of ~40 %. According to this temperature effect, an average temperature increase in 2 °C as projected for the sea surface by the end of this century could increase sinking velocities by about 6 % which might have feedbacks on carbon export into the deep ocean

Correlates of gross motor competence in children and adolescents: A systematic review and meta-analysis

Background Gross motor competence confers health benefits, but levels in children and adolescents are low. While interventions can improve gross motor competence, it remains unclear which correlates should be targeted to ensure interventions are most effective, and for whom targeted and tailored interventions should be developed. Objective The aim of this systematic review was to identify the potential correlates of gross motor competence in typically developing children and adolescents (aged 3–18 years) using an ecological approach. Methods Motor competence was defined as gross motor skill competency, encompassing fundamental movement skills and motor coordination, but excluding motor fitness. Studies needed to assess a summary score of at least one aspect of motor competence (i.e., object control, locomotor, stability, or motor coordination). A structured electronic literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Six electronic databases (CINAHL Complete, ERIC, MEDLINE Complete, PsycINFO, Scopus and SPORTDiscus with Full Text) were searched from 1994 to 5 August 2014. Meta-analyses were conducted to determine the relationship between potential correlates and motor competency if at least three individual studies investigated the same correlate and also reported standardized regression coefficients. Results A total of 59 studies were identified from 22 different countries, published between 1995 and 2014. Studies reflected the full range of age groups. The most examined correlates were biological and demographic factors. Age (increasing) was a correlate of children’s motor competence. Weight status (healthy), sex (male) and socioeconomic background (higher) were consistent correlates for certain aspects of motor competence only. Physical activity and sport participation constituted the majority of investigations in the behavioral attributes and skills category. Whilst we found physical activity to be a positive correlate of skill composite and motor coordination, we also found indeterminate evidence for physical activity being a correlate of object control or locomotor skill competence. Few studies investigated cognitive, emotional and psychological factors, cultural and social factors or physical environment factors as correlates of motor competence. Conclusion This systematic review is the first that has investigated correlates of gross motor competence in children and adolescents. A strength is that we categorized correlates according to the specific ways motor competence has been defined and operationalized (object control, motor coordination, etc.), which enables us to have an understanding of what correlates assist what types of motor competence. Indeed our findings do suggest that evidence for some correlates differs according to how motor competence is operationalized

Anaerobes in Bioelectrochemical Systems

In bioelectrochemical systems (BES), the catalytic activity of anaerobic microorganisms generates electrons at the anode which can be used, for example, for the production of electricity or chemical compounds. BES can be used for various purposes, including wastewater treatment, production of electricity, fuels and chemicals, biosensors, bioremediation, and desalination. Electrochemically active microorganisms are widely present in the environment and they can be found, in sediment, soil, compost, wastewaters and their treatment plants. Exoelectrogens are microorganisms capable of donating electrons to anode electrode or accepting electrons from cathode electrode and are mainly responsible for current generation or use in BES. However, current generation from fermentable substrates often requires the presence of electrochemically inactive microorganisms that break down complex substrates into metabolites which can be further utilized by exoelectrogens. The growth and electron transfer efficiency of anaerobes depend on several parameters, such as system architecture, electrode material and porosity, electrode potential and external resistance, pH, temperature, substrate concentration, organic loading rate, and ionic strength. In this chapter, the principles and microbiology of bioelectrochemical systems as well as selective factors for exoelectrogens are reviewed. The anaerobic microorganisms and their electron transfer mechanisms at the anode and cathode are described and future aspects are briefly discussed.acceptedVersionNon peer reviewe

Do school-based interventions focusing on physical activity, fitness or fundamental movement skill competency produce a sustained impact in these outcomes in children and adolescents? A systematic review of follow-up studies

Background: There is emerging evidence for positive associations between physical activity (PA), fitness, and fundamental movement skill (FMS) competence, for both children and adolescents. Current reviews of interventions to improve these variables note few studies conduct follow-up assessments to assess behavior maintenance. Objective: The aim of this systematic review was to determine whether typically developing children and adolescents (aged 3–18 years) who have participated in school-based interventions have sustained outcomes in PA, fitness, and/or FMS. Methods: A systematic search of six electronic databases (CINAHL® Plus with Full Text, Ovid MEDLINE®, SPORTDiscus™, Scopus, PsycINFO® and ERIC) was conducted from 1995 to 26 July 2012. Included studies were school-based studies (including randomized controlled trials, longitudinal cohort, quasi-experimental, and experimental) that had a positive effect at post intervention in at least one variable and had a follow-up PA, fitness, or FMS assessment at least 6 months after the post-intervention assessment. Risk of bias assessment was guided by the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” statement. Results: The search identified 14 articles, and some studies addressed multiple outcomes: 13 articles assessed PA; three assessed fitness; and two assessed FMS. No study in this review met four key methodological criteria that have been shown to influence results, i.e., clarity on the randomization process, assessor blinding, analyzing participants in their original groups, and retaining sufficient participants through the entire study. Three-quarters (ten of 13) of the studies addressing PA, reported PA behavior change maintenance. The length of follow-up ranged from 6 months to 20 years, and the degree of PA difference reported was between 3 and 14 min per day. Only one of the three studies assessing fitness reported a sustained impact, whilst both studies that assessed FMS reported maintenance of effects. Conclusion: It is likely that PA is a sustainable outcome from interventions in children and adolescents, and there is reasonable evidence that interventions of longer than 1 year and interventions that utilize a theoretical model or framework are effective in producing this sustained impact. It would seem probable that FMS are a sustainable outcome in children and adolescents; however, this finding should be viewed with caution given the lack of studies and the risk of bias assessment. More research is needed to assess the sustainability of fitness interventions as this review only included a handful of studies that addressed fitness and only one of these studies found a sustained impact

Genomic analysis of local variation and recent evolution in Plasmodium vivax

The widespread distribution and relapsing nature of Plasmodium vivax infection present major challenges for malaria elimination. To characterise the genetic diversity of this parasite within individual infections and across the population, we performed deep genome sequencing of >200 clinical samples collected across the Asia-Pacific region, and analysed data on >300,000 SNPs and 9 regions of the genome with large structural variations. Individual infections showed complex patterns of genetic structure, with variation not only in the number of dominant clones but also in their level of relatedness and inbreeding. At the population level, we observed strong signals of recent evolutionary selection both in known drug resistance genes and at novel loci, and these varied markedly between geographical locations. These findings reveal a dynamic landscape of local evolutionary adaptation in P. vivax populations, and provide a foundation for genomic surveillance to guide effective strategies for control and elimination