Life History of the River Shiner, Notropis blennius (Cyprinidae), in the Arkansas River of Western Arkansas

The reproductive cycle, food habits, and age and growth of the river shiner, Notropis blennius (Girard), in the Arkansas River of western Arkansas were studied from May 1996 through October 1997. Based on gonadosomatic indices and mean ovumd iameters of females, tubercle development in males, and the first appearance of young-of-year in samples, the breeding season extended from June through August in both 1996 and 1997. The river shiner is a diurnal, generalist feeder that forages on a wide variety of food items. In all four seasons, detritus dominated the diets of adults and juveniles in terms of volume and frequency of occurrence. Aquatic insects and algae were also important food items. It is a short-lived, r-strategist; it has a maximum life expectancy of about two years and has successfully maintained stable populations in the Arkansas River for more than 30 years after the construction of the Arkansas River Navigation System

Schools closed during the pandemic: revelations about the well-being of ‘lower-attaining’ primary-school children

This article is unique because it fills a significant gap among Covid-19 related educational research in three ways. First, it analyses data from face-to-face interviews with 23 children, whilst most Covid-19 related research has been based on online data collection methods. Second, it involves ‘lower-attaining’ children who were already part of an ongoing five-year research project set in England, UK. Third, it captures a ‘before’ and ‘after’ picture of the children’s experiences during schooling-as-normal and after the two periods of school closures, in relation to their well-being. Within the context of Seligman’s PERMA theory, we found that the absence-of-schooling-as-normal had adversely affected their well-being, but in so doing, the children’s perspective on schooling had altered, as they had missed being part of something bigger than themselves, in a setting which offered socialisation, structure and purpose

National Curriculum and Assessment in England and the continuing narrowed experiences of lower-attainers in primary schools

A considerable body of global educational literature has examined how schooling policy based on measuring and managing performance has narrowed children’s access both to curriculum breadth and to diversity in pedagogy. This article approaches these curriculum dilemmas within the global concern for children’s wellbeing and social justice. In particular, it focuses on the experiences of children designated by this system as lower-attaining, which is a much under-researched aspect of these concerns. Based on an innovative five-year life-history study of 23 seven to 12 year-old lower-attaining school-children in the English system, this article examines how these children themselves depicted their schooling experiences. We conclude, drawing on term-by-term experiences narrated by these children, that the current curriculum and assessment arrangements narrowed their opportunities for participation in engaged learning, especially in comparison to higher-attaining children; which undermined their wellbeing and brought social justice into question. The children highlighted the negative impact of curriculum emphases on mathematics and English rather than on non-core and outside-school curriculum areas for lower-attaining in particular; and the emphasis on attainment rather than participation in learning. They had few opportunities to have their specific preferences validated, leading in some cases to these lower-attainers being excluded from participation in school-learning

Design of egocentric network-based studies to estimate causal effects under interference

Many public health interventions are conducted in settings where individuals are connected to one another and the intervention assigned to randomly selected individuals may spill over to other individuals they are connected to. In these spillover settings, the effects of such interventions can be quantified in several ways. The average individual effect measures the intervention effect among those directly treated, while the spillover effect measures the effect among those connected to those directly treated. In addition, the overall effect measures the average intervention effect across the study population, over those directly treated along with those to whom the intervention spills over but who are not directly treated. Here, we develop methods for study design with the aim of estimating individual, spillover, and overall effects. In particular, we consider an egocentric network-based randomized design in which a set of index participants is recruited from the population and randomly assigned to treatment, while data are also collected from their untreated network members. We use the potential outcomes framework to define two clustered regression modeling approaches and clarify the underlying assumptions required to identify and estimate causal effects. We then develop sample size formulas for detecting individual, spillover, and overall effects. We investigate the roles of the intra-class correlation coefficient and the probability of treatment allocation on the required number of egocentric networks with a fixed number of network members for each egocentric network and vice-versa.Comment: 30 pages for main text including figures and tables, 5 figures and 3 table

Development of Low Frequency Electron Paramagnetic Resonance Methods and Instrumentation for Biological Applications

EPR is a powerful biophysical tool that can be used to measure tumor physiology. With the addition of magnetic field gradients, the spectral properties of paramagnetic species can be mapped. To facilitate EPR imaging, methods and instrumentation at frequencies between 250 MHz and 1 GHz were developed. At low spin concentrations, the rapid scan background signal is often many times larger than the EPR signal of interest. To help remove the background contribution, a data acquisition procedure that takes advantage of a cross-loop resonator and bipolar power supplies was developed at 250 MHz. In this procedure, two scans are collected. Relative to the first scan, in the second scan the magnetic field (B0) is reversed and the phase of the rapid scan field is offset by 180°. This results in an inversion of the EPR signal and no net change to the background. The difference between the scans is calculated to cancel the background and enhance the EPR signal by the square root of 2. The procedure was also applied to data at 700 MHz and 980 MHz. A table-top arbitrary waveform generator (AWG) based rapid scan and pulse spectrometer was designed to operate at frequencies between 700 MHz and 1 GHz using both cross-loop and reflection resonators. The frequency range was selected to provide adequate signal to noise and an imaging penetration depth appropriate for imaging mice. Characterization of the spectrometer including the noise figure, gain, magnetic field homogeneity, source noise, resonators, and gradient fields is reported. To demonstrate the imaging capabilities of the instrument, rapid scan images were collected of nitroxide and trityl radicals in vitro up to 4 dimensions. New methods were tested that use rapid scan, frequency steps, and field jumps to measure electron spin lattice relaxation (T1) at 1 GHz. Overall good agreement of the relaxation times was observed between the new methods and conventional techniques. However, the uncertainty associated with the rapid scan method is greater due to the low number of points that define the recovery curve. In the frequency stepped method, the resonator bandwidth limits samples to ones with narrow lines. Preliminary results of the field jump method are presented. Finally, excitation bandwidth and power requirements of a new exponential sine shaped pulse produced with an AWG are compared to conventional rectangular pulses at 1.5 GHz. For the same amount of power, a higher resonator Q can be utilized with the exponential sine pulse yielding higher sensitivity and an increased excitation uniformity

Systematic review and meta-analysis of randomised controlled trials on the effects of potassium supplements on serum potassium and creatinine

Objectives: High potassium intake could prevent stroke, but supplementation is considered hazardous. We assessed the effect of oral potassium supplementation on serum or plasma potassium levels and renal function. Setting: We updated a systematic review of the effects of potassium supplementation in randomised clinical trials carried out worldwide, published in 2013, extending it to July 2015. We followed the PRISMA guidelines. Participants: Any individual taking part in a potassium supplementation randomised clinical trial. Studies included met the following criteria: randomised clinical trials, potassium supplement given and circulating potassium levels reported. Intervention: Oral potassium supplementation. Primary outcome measures: Serum or plasma potassium and serum or plasma creatinine. Results: A total of 20 trials (21 independent groups) were included (1216 participants from 12 different countries). All but 2 were controlled (placebo n=16, control n=2). Of these trials, 15 were crossover, 4 had a parallel group and 1 was sequential. The duration of supplementation varied from 2 to 24 weeks and the amount of potassium given from 22 to 140 mmol/day. In the pooled analysis, potassium supplementation caused a small but significant increase in circulating potassium levels (weighted mean difference (WMD) 0.14 mmol/L, 95% CI 0.09 to 0.19, p<1×10−5), not associated with dose or duration of treatment. The average increase in urinary potassium excretion was 45.75 mmol/24 hours, 95% CI 38.81 to 53.69, p<1×10−5. Potassium supplementation did not cause any change in circulating creatinine levels (WMD 0.30 µmol/L, 95% CI −1.19 to 1.78, p=0.70). Conclusions: In short-term studies of relatively healthy persons, a moderate oral potassium supplement resulted in a small increase in circulating potassium levels and no change in renal function

Conserved noncoding sequences highlight shared components of regulatory networks in dicotyledonous plants

Conserved noncoding sequences (CNSs) in DNA are reliable pointers to regulatory elements controlling gene expression. Using a comparative genomics approach with four dicotyledonous plant species (Arabidopsis thaliana, papaya [Carica papaya], poplar [Populus trichocarpa], and grape [Vitis vinifera]), we detected hundreds of CNSs upstream of Arabidopsis genes. Distinct positioning, length, and enrichment for transcription factor binding sites suggest these CNSs play a functional role in transcriptional regulation. The enrichment of transcription factors within the set of genes associated with CNS is consistent with the hypothesis that together they form part of a conserved transcriptional network whose function is to regulate other transcription factors and control development. We identified a set of promoters where regulatory mechanisms are likely to be shared between the model organism Arabidopsis and other dicots, providing areas of focus for further research

The influence of facility and home pen design on the welfare of the laboratory-housed dog

We have an ethical and scientific obligation to Refine all aspects of the life of the laboratory-housed dog. Across industry there are many differences amongst facilities, home pen design and husbandry, as well as differences in features of the dogs such as strain, sex and scientific protocols. Understanding how these influence welfare, and hence scientific output is therefore critical. A significant proportion of dogs&rsquo; lives are spent in the home pen and as such, the design can have a considerable impact on welfare. Although best practice guidelines exist, there is a paucity of empirical evidence to support the recommended Refinements and uptake varies across industry. In this study, we examine the effect of modern and traditional home pen design, overall facility design, husbandry, history of regulated procedures, strain and sex on welfare-indicating behaviours and mechanical pressure threshold. Six groups of dogs from two facilities (total n=46) were observed in the home pen and tested for mechanical pressure threshold. Dogs which were housed in a purpose-built modern facility or in a modern design home pen showed the fewest behavioural indicators of negative welfare (such as alert or pacing behaviours) and more indicators of positive welfare (such as resting) compared to those in a traditional home pen design or traditional facility. Welfare indicating behaviours did not vary consistently with strain, but male dogs showed more negative welfare indicating behaviours and had greater variation in these behaviours than females. Our findings showed more positive welfare indicating behaviours in dogs with higher mechanical pressure thresholds. We conclude that factors relating to the design of home pens and implementation of Refinements at the facility level have a significant positive impact on the welfare of laboratory-housed dogs, with a potential concomitant impact on scientific endpoints

Mission Simulation Toolkit

The Mission Simulation Toolkit (MST) is a flexible software system for autonomy research. It was developed as part of the Mission Simulation Facility (MSF) project that was started in 2001 to facilitate the development of autonomous planetary robotic missions. Autonomy is a key enabling factor for robotic exploration. There has been a large gap between autonomy software (at the research level), and software that is ready for insertion into near-term space missions. The MST bridges this gap by providing a simulation framework and a suite of tools for supporting research and maturation of autonomy. MST uses a distributed framework based on the High Level Architecture (HLA) standard. A key feature of the MST framework is the ability to plug in new models to replace existing ones with the same services. This enables significant simulation flexibility, particularly the mixing and control of fidelity level. In addition, the MST provides automatic code generation from robot interfaces defined with the Unified Modeling Language (UML), methods for maintaining synchronization across distributed simulation systems, XML-based robot description, and an environment server. Finally, the MSF supports a number of third-party products including dynamic models and terrain databases. Although the communication objects and some of the simulation components that are provided with this toolkit are specifically designed for terrestrial surface rovers, the MST can be applied to any other domain, such as aerial, aquatic, or space