An Exploration of Supports for Increasing Classroom Physical Activity within Elementary Schools

Classroom-based physical activity (CBPA) can significantly benefit students’ health and educational outcomes, but many teachers do not utilize CBPA. This study examined teachers’ perceptions about the value and impact of several approaches to support CBPA implementation, and teachers’ weekly self-reported CBPA use. Interviews were conducted with 35 classroom teachers (including those using and not using CBPA) at two public elementary schools, and CBPA tracking logs were collected on a weekly basis. Interview transcripts were interpreted through key domains within implementation science. On average, teachers reported using one activity every other day. Interview data revealed that utilizing professional collaboration time for peer-to-peer feedback and getting informal support from the school’s physical education teacher both have some promise for increasing implementation of CBPA. However, teachers largely felt these strategies were unnecessary. Explicit administrator support was reported by teachers as the most promising mechanism for increasing their CBPA implementation

Denaturation transition of stretched DNA

We generalize the Poland-Scheraga model to consider DNA denaturation in the presence of an external stretching force. We demonstrate the existence of a force-induced DNA denaturation transition and obtain the temperature-force phase diagram. The transition is determined by the loop exponent $c$ for which we find the new value $c=4\nu-1/2$ such that the transition is second order with $c=1.85<2$ in $d=3$. We show that a finite stretching force $F$ destabilizes DNA, corresponding to a lower melting temperature $T(F)$, in agreement with single-molecule DNA stretching experiments.Comment: 5 pages, 3 figure

Influences of physical oceanographic processes on chlorophyll distributions in coastal and estuarine waters of the South Atlantic Bight

Coastal and estuarine waters of the South Atlantic Bight are highly productive, with primary production of 600-700 gC/m2/y. While controls and fate of this production are conceptually well understood, the importance of meteorology and physical circulation processes on phytoplankton has not received equivalent attention. Here, we describe the effects of wind stress and tidal currents on temporal and spatial distributions of phytoplankton biomass represented as chlorophyll a (chl a). Moored instruments were deployed and shipboard sampling was conducted in the North Edisto estuary (South Carolina) and adjacent inner shelf waters during four, two-week field studies in May and August 1993, and June and September 1994. Local wind regimes induced upwelling- and downwelling-favorable conditions which strengthened or reduced vertical density stratification in the coastal frontal zone, respectively, and shifted the location of the front. Chl a in shelf waters was more or less homogenous independent of the wind regime, while chl a on the estuary delta was generally vertically stratified. Within the estuary, chl a concentrations were positively correlated with the alongshore component of wind stress; chl a was not correlated with the weaker cross-shelf component of wind stress. Highest chl a occurred during strong downwelling-favorable events. The quick response time to wind forcing (6-12 hrs) implied a direct effect on chl a distributions and not a stimulation of growth processes. The source of the elevated chl a in response to wind forcing was apparently resuspension of settled and epibenthic algal cells. Tidal currents also influenced the vertical distribution and concentration of chl a. Time series sampling on the estuary delta showed that, with increasing velocity of ebb and flood tide currents, the relative contributions of pennate and centric diatoms with attached detritus and sand grains also increased, indicating that tidal resuspension of settled and epibenthic microalgae also occurred. Vertical stratification of chl a (highest concentrations near the bottom) began to degrade upon mixing by tidal currents with velocities as low as 10 cm/sec. Homogenization of 5-7 m water columns was fully achieved at velocities of 20-30 cm/sec. The data document the direct and comparatively immediate (timescales of minuteshours) impact of tidal and wind energy on concentrations and distribution patterns of phytoplankton in coastal and estuarine waters of the South Atlantic Bight

Environmental, social and governance e o ciclo de vida das firmas: evidências no mercado brasileiro

O estudo analisou a associação entre o environmental, social and governance (ESG) e os estágios de ciclo de vida das empresas brasileiras de capital aberto listadas na B3 S.A. – Brasil, Bolsa, Balcão (B3) no período de 2010 a 2020. Explora-se uma lacuna teórica sobre a relação dos estágios de ciclo de vida das empresas com iniciativas ESG no Brasil, um país emergente. As evidências são relevantes para a compreensão de como os estágios do ciclo de vida funcionam como sinalizadores do nível de ações ESG das companhias e para demonstrar como o mercado percebe essas ações e sua capacidade de geração de valor. A pesquisa traz insights de que os fundamentos da teoria dos estágios de ciclo de vida da firma funcionam como indicadores para diversas perspectivas organizacionais, até mesmo para as práticas ESG. A amostra foi composta por 109 empresas cujos dados foram coletados na Thomson Reuters® e analisados por meio de regressão múltipla. Para análise dos ciclos de vida, utilizou-se o modelo proposto por Dickinson (2011). Cabe destacar que os dados também foram analisados utilizando o efeito fixo como estimação do modelo econométrico, porém houve perda da significância estatística na relação encontrada, possivelmente devido à seleção da amostra realizada no painel desbalanceado. A partir da amostra analisada e dos modelos econométricos utilizados, os resultados indicam que as empresas em estágio de nascimento e turbulência apresentam menores níveis de práticas ESG, notadamente nos pilares ambiental e social, se comparadas às empresas em estágio de maturidade. Os achados também evidenciaram que as iniciativas ESG no mercado de capitais brasileiro estão associadas com medidas de rentabilidade, liquidez, endividamento, valor de mercado e número de analistas das organizações. A pesquisa contribui para a análise da associação entre a adoção de práticas ESG e os estágios de ciclo de vida das empresasem um mercado emergente, com reflexões aos stakeholders a respeito do direcionamento de recursos em ações sustentáveis.The study analyzed the association between environmental, social and governance (ESG) and the life cycle stages of Brazilian publicly-traded companies listed on the B3 S.A. – Brasil, Bolsa, Balcão (B3) from 2010 to 2020. It explores a theoretical gap regarding the relationship between the life cycle stages of companies and ESG initiatives in Brazil, an emerging country. The findings are relevant for understanding how the life cycle stages act as signals of the level of ESG actions of companies and how the market perceives these actions and their ability to create value. The research provides evidence that the fundamentals of the firm life cycle theory function as indicators for several organizational perspectives, including ESG practices. The sample consisted of 109 companies whose data were collected from Thomson Reuters® and analyzed using multiple regression. The model proposed by Dickinson (2011) was used to analyze the life cycle stages. It should be highlighted that the data were also analyzed using the fixed effect as an estimation of the econometric model, but there was a loss of statistical significance in the relationship found, possibly due to the sample selection performed in the unbalanced panel. Based on the sample analyzed and the econometric models used, the results indicate that companies in the birth and turbulence stages have lower levels of ESG practices, particularly in the environmental and social pillars, compared to companies in the maturity stage. The findings also show that ESG initiatives in the Brazilian capital market are associated with measures of companies’ profitability, liquidity, indebtedness, market value, and number of analysts. The research contributes to the analysis of the relationship between the adoption of ESG practices and the life cycle stages of companies in an emerging market, with implications for stakeholders regarding the targeting of resources to sustainable actions

Unzipping Kinetics of Double-Stranded DNA in a Nanopore

We studied the unzipping kinetics of single molecules of double-stranded DNA by pulling one of their two strands through a narrow protein pore. PCR analysis yielded the first direct proof of DNA unzipping in such a system. The time to unzip each molecule was inferred from the ionic current signature of DNA traversal. The distribution of times to unzip under various experimental conditions fit a simple kinetic model. Using this model, we estimated the enthalpy barriers to unzipping and the effective charge of a nucleotide in the pore, which was considerably smaller than previously assumed.Comment: 10 pages, 5 figures, Accepted: Physics Review Letter

Dallas with balls: televized sport, soap opera and male and female pleasures

Two of the most popular of television genres, soap opera and sports coverage have been very much differentiated along gender lines in terms of their audiences. Soap opera has been regarded very much as a 'gynocentric' genre with a large female viewing audience while the audiences for television sport have been predominantly male. Gender differentiation between the genres has had implications for the popular image of each. Soap opera has been perceived as inferior; as mere fantasy and escapism for women while television sports has been perceived as a legitimate, even edifying experience for men. In this article the authors challenge the view that soap opera and television sport are radically different and argue that they are, in fact, very similar in a number of significant ways. They suggest that both genres invoke similar structures of feeling and sensibility in their respective audiences and that television sport is a 'male soap opera'. They consider the ways in which the viewing context of each genre is related to domestic life and leisure, the ways in which the textual structure and conventions of each genre invoke emotional identification, and finally, the ways in which both genres re-affirm gender identities

Egg development, hatching rhythm and moult patterns in Paralomos spinosissima (Decapoda: Anomura: Paguroidea: Lithodidae) from South Georgia waters (Southern Ocean)

Larval release, hatching rhythms and moult patterns were examined in a captive population of the subantarctic lithodid, Paralomis spinosissima from the South Georgia and Shag Rocks region. Larvae hatched throughout the year with the majority of females starting to release larvae at the end of the austral summer and beginning of autumn. Larval release continued over a period of up to 9 weeks with high variability in the numbers that hatched each day. A similar seasonal pattern to hatching was evident in the moulting of females. Intermoult period for two adult females (CL = 63 and 85 mm) ranged from 894 to 1,120 days while an intermoult period for males was estimated to be in excess of 832 days. The results are consistent with other species of Paralomis and are discussed in relation to physiological and environmental adaptations to the cold-water conditions south of the Antarctic Convergence