85 research outputs found
Identifying multiple stressor controls on phytoplankton dynamics in the River Thames (UK) using high-frequency water quality data
River phytoplankton blooms can pose a serious risk to water quality and the structure and function of aquatic
ecosystems. Developing a greater understanding of the physical and chemical controls on the timing, magnitude
and duration of blooms is essential for the effective management of phytoplankton development. Five years of
weekly water quality monitoring data along the River Thames, southern England were combined with hourly
chlorophyll concentration (a proxy for phytoplankton biomass), flow, temperature and daily sunlight data
from the mid-Thames. Weekly chlorophyll data was of insufficient temporal resolution to identify the causes
of short term variations in phytoplankton biomass. However, hourly chlorophyll data enabled identification of
thresholds in water temperature (between 9 and 19 °C) and flow (<30 m3 sâ1) that explained the development
of phytoplankton populations. Analysis showed that periods of high phytoplankton biomass and growth rate
only occurred when these flow and temperature conditions were within these thresholds, and coincided with periods
of long sunshine duration, indicating multiple stressor controls. Nutrient concentrations appeared to have
no impact on the timing or magnitude of phytoplankton bloom development, but severe depletion of dissolved
phosphorus and silicon during periods of high phytoplankton biomass may have contributed to some bloom collapses
through nutrient limitation. This study indicates that for nutrient enriched rivers such as the Thames,manipulating residence time (through removing impoundments) and light/temperature (by increasing riparian
tree shading) may offer more realistic solutions than reducing phosphorus concentrations for controlling excessive
phytoplankton biomass
Inequalities in child development at school entry: a repeated cross-sectional analysis of the Australian Early Development Census 2009â2018
Background: Australia is the only developed country to consistently undertake a developmental census of its children nationwide. The repeated collection of the Australian Early Development Census (AEDC) has provided an unprecedented opportunity to examine the prevalence of developmental vulnerability across Australia's states and territories, the socio-economic distribution of developmental vulnerability across jurisdictions, and how these distributions might have changed over time.
Methods: This study employed multivariable logistic regressions to estimate the probability of developmental vulnerability within each jurisdiction and AEDC collection year (2009 to 2018), adjusting for jurisdictional differences in socio-demographic characteristics. To explore socio-economic inequalities in child development, adjusted slope index of inequality (SII) models were utilised. Findings: The results of this study found reductions in the adjusted prevalence of developmental vulnerability over time in Western Australia (26% to 20%) and Queensland (30% to 25%), with an increase observed in the Australian Capital Territory (27% to 30%). Analysis also indicated an increase in socio-economic inequalities over time in the Northern Territory (+12%), the Australian Capital Territory (+6%) and Tasmania (+4%). Sensitivity analysis found these effects to be robust with an alternative measure of socio-economic position. Interpretation: There is considerable variation in the prevalence and socio-economic inequalities in developmental vulnerability across Australia's jurisdictions. Future research should explore the policy drivers in early childhood education and health contributing to the findings of this study, with a particular focus on jurisdictions where there have been notable changes in developmental vulnerability and socio-economic inequality over time.
Funding: Analyses were funded under research contract by the Department of Education, Skills and Employment. Prof Brinkman is supported by a National Health and Medical Research Council fellowship, APP1160185.Luke R. Collier, Tess Gregory, Yasmin Harman-Smith, Angela Gialamas, Sally A. Brinkma
Professionalism, Golf Coaching and a Master of Science Degree: A commentary
As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues
Inferential Transitions
This paper provides a naturalistic account of inference. We posit that the core of inference is constituted by bare inferential transitions (BITs), transitions between discursive mental representations guided by rules built into the architecture of cognitive systems. In further developing the concept of BITs, we provide an account of what Boghossian [2014] calls âtakingââthat is, the appreciation of the rule that guides an inferential transition. We argue that BITs are sufficient for implicit taking, and then, to analyse explicit taking, we posit rich inferential transitions (RITs), which are transitions that the subject is disposed to endorse
Changes in water quality of the River Frome (UK) from 1965 to 2009: is phosphorus mitigation finally working?
The water quality of the River Frome, Dorset, southern England, was monitored at weekly intervals from 1965
until 2009. Determinands included phosphorus, nitrogen, silicon, potassium, calcium, sodium, magnesium,
pH, alkalinity and temperature. Nitrate-N concentrations increased from an annual average of 2.4 mg lâ1 in
the mid to late 1960s to 6.0 mg lâ1 in 2008â2009, but the rate of increase was beginning to slow. Annual
soluble reactive phosphorus (SRP) concentrations increased from 101 ÎŒg lâ1 in the mid 1960s to a maximum
of 190 ÎŒg lâ1 in 1989. In 2002, there was a step reduction in SRP concentration (average=88 ÎŒg lâ1 in 2002â
2005), with further improvement in 2007â2009 (average=49 ÎŒg lâ1), due to the introduction of phosphorus
stripping at sewage treatment works. Phosphorus and nitrate concentrations showed clear annual cycles,
related to the timing of inputs from the catchment, and within-stream bioaccumulation and release. Annual
depressions in silicon concentration each spring (due to diatom proliferation) reached a maximum between
1980 and 1991, (the period of maximum SRP concentration) indicating that algal biomass had increased
within the river. The timing of these silicon depressions was closely related to temperature. Excess carbon
dioxide partial pressures (EpCO2) of 60 times atmospheric CO2 were also observed through the winter periods
from 1980 to 1992, when phosphorus concentration was greatest, indicating very high respiration rates due to
microbial decomposition of this enhanced biomass. Declining phosphorus concentrations since 2002 reduced
productivity and algal biomass in the summer, and EpCO2 through the winter, indicating that sewage
treatment improvements had improved riverine ecology. Algal blooms were limited by phosphorus, rather
than silicon concentration. The value of long-term water quality data sets is discussed. The data from this
monitoring programme are made freely available to the wider science community through the CEH data
portal (http://gateway.ceh.ac.uk/
Alternative migratory tactics in brown trout (Salmo trutta) are underpinned by divergent regulation of metabolic but not neurological genes
Abstract The occurrence of alternative morphs within populations is common, but the underlying molecular mechanisms remain poorly understood. Many animals, for example, exhibit facultative migration, where two or more alternative migratory tactics (AMTs) coexist within populations. In certain salmonid species, some individuals remain in natal rivers all their lives, while others (in particular, females) migrate to sea for a period of marine growth. Here, we performed transcriptional profiling (âRNAâseqâ) of the brain and liver of male and female brown trout to understand the genes and processes that differentiate between migratory and residency morphs (AMTâassociated genes) and how they may differ in expression between the sexes. We found tissueâspecific differences with a greater number of genes expressed differentially in the liver (n = 867 genes) compared with the brain (n = 10) between the morphs. Genes with increased expression in resident livers were enriched for Gene Ontology terms associated with metabolic processes, highlighting key molecularâgenetic pathways underlying the energetic requirements associated with divergent migratory tactics. In contrast, smoltâbiased genes were enriched for biological processes such as response to cytokines, suggestive of possible immune function differences between smolts and residents. Finally, we identified evidence of sexâbiased gene expression for AMTâassociated genes in the liver (n = 12) but not the brain. Collectively, our results provide insights into tissueâspecific gene expression underlying the production of alternative life histories within and between the sexes, and point toward a key role for metabolic processes in the liver in mediating divergent physiological trajectories of migrants versus residents
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