Sinus histiocytosis with massive lymphadenopathy

Two cases of a recently described entity, 'sinus histiocytosis with massive lymphadenopathy,' occurring in Black males, are reported. Prominent cervical adenopathy was the main presenting feature in both. Histologically, these nodes were characterised by pronounced proliferation of sinus histiocytes which showed phagocytosis of blood cells, predominantly Iymphocytes. One of the patients has been followed up for 9 years and has remained clinically well despite persistence of the adenopathy. The importance of recognition of this condition is stressed in order to obviate unnecessarily radical therapy for a mistaken diagnosis of malignancy.S. Afr. Med. J., 48, 451 (1974)

Carcass Characteristics of Bulls, Heifers and Steers as Influenced by Ration and Market Weight

High feed grain prices, a growing worldwide demand for animal protein, and increasing demand for lean, high quality beef make it imperative that beef volume and production efficiency increase. Because of high feed costs it is important to know how concentrate level in the ration and market weight influence production efficiency and carcass composition of different sex groups. The purpose of this study was to evaluate the effects of market weight and ration concentrate level on the quant itative and qualitative carcass traits of yearling bulls, bull calves, heifers and steers

Medical Mistrust and Colorectal Cancer Screening Among African Americans

Despite well-documented benefits of colorectal cancer (CRC) screening, African Americans are less likely to be screened and have higher CRC incidence and mortality than Whites. Emerging evidence suggests medical mistrust may influence CRC screening disparities among African Americans. The goal of this systematic review was to summarize evidence investigating associations between medical mistrust and CRC screening among African Americans, and variations in these associations by gender, CRC screening type, and level of mistrust. MEDLINE, CINAHL, Web of Science, PsycINFO, Google Scholar, Cochrane Database, and EMBASE were searched for English-language articles published from January 2000 to November 2016. 27 articles were included for this review (15 quantitative, 11 qualitative and 1 mixed methods study). The majority of quantitative studies linked higher mistrust scores with lower rates of CRC screening among African Americans. Most studies examined mistrust at the physician level, but few quantitative studies analyzed mistrust at an organizational level (i.e. healthcare systems, insurance, etc.). Quantitative differences in mistrust and CRC screening by gender were mixed, but qualitative studies highlighted fear of experimentation and intrusiveness of screening methods as unique themes among African American men. Limitations include heterogeneity in mistrust and CRC measures, and possible publication bias. Future studies should address methodological challenges found in this review, such as limited use of validated and reliable mistrust measures, examination of CRC screening outcomes beyond beliefs and intent, and a more thorough analysis of gender roles in the cancer screening process

The emergence of performance trade-offs during local adaptation: insights from experimental evolution

Environmental heterogeneity is considered a general explanation for phenotypic diversification, particularly when heterogeneity causes populations to diverge via local adaptation. Performance trade-offs, such as those stemming from antagonistic pleiotropy, are thought to contribute to the maintenance of diversity in this scenario. Specifically, alleles that promote adaptation in one environment are expected to promote maladaptation in alternative environments. Contrary to this expectation, however, alleles that underlie locally adaptive traits often fail to exhibit fitness costs in alternative environments. Here, we attempt to explain this paradox by reviewing the results of experimental evolution studies, including a new one of our own, that examined the evolution of trade-offs during adaptation to homogeneous versus heterogeneous environments. We propose that when pleiotropic effects vary, whether or not trade-offs emerge among diverging populations will depend critically on ecology. For example, adaptation to a locally homogeneous environment is more likely to occur by alleles that are antagonistically pleiotropic than adaptation to a locally heterogeneous environment, simply because selection is blind to costs associated with environments that are not experienced locally. Our literature review confirmed the resulting prediction that performance trade-offs were more likely to evolve during selection in homogeneous than heterogeneous environments. The nature of the environmental heterogeneity (spatial versus temporal) and the length of the experiment also contributed in predictable ways to the likelihood that performance trade-offs evolved

Vulnerability to bullying in children with a history of specific speech and language difficulties

This is an electronic version of an article published in Lindsay, Geoff and Dockrell, Julie and Mackie, Clare (2008) Vulnerability to bullying in children with a history of specific speech and language difficulties. European Journal of Special Needs Education, 23 (1). pp. 1-16. European Journal of Special Needs Education is available online at: http://www.informaworld.com/10.1080/0885625070179120

The adaptive potential of subtropical rainbowfish in the face of climate change: heritability and heritable plasticity for the expression of candidate genes

Whilst adaptation and phenotypic plasticity might buffer species against habitat degradation associated with global climate change, few studies making such claims also possess the necessary and sufficient data to support them. Doing so requires demonstration of heritable variation in traits affecting fitness under new environmental conditions. We address this issue using an emerging aquatic system to study adaptation to climate change, the crimson-spotted rainbowfish (Melanotaenia duboulayi), a freshwater species from a region of eastern Australia projected to be affected by marked temperature increases. Captive born M. duboulayi of known pedigree were used to assess the long-term effects of contemporary and 2070-projected summer temperatures on the expression of genes previously identified in a climate change transcriptomics (RNA-Seq) experiment. Nearly all genes responded to increasing temperature. Significant additive genetic variance explained a moderate proportion of transcriptional variation for all genes. Most genes also showed broad-sense genetic variation in transcriptional plasticity. Additionally, molecular pathways of candidate genes co-occur with genes inferred to be under climate-mediated selection in wild M. duboulayi populations. Together, these results indicate the presence of existing variation in important physiological traits, and the potential for adaptive responses to a changing thermal environment.R.J. Scott McCairns, Steve Smith, Minami Sasaki, Louis Bernatchez and Luciano B. Beheregara

Magnetoresistance of Two-Dimensional Fermions in a Random Magnetic Field

We perform a semiclassical calculation of the magnetoresistance of spinless two-dimensional fermions in a long-range correlated random magnetic field. In the regime relevant for the problem of the half filled Landau level the perturbative Born approximation fails and we develop a new method of solving the Boltzmann equation beyond the relaxation time approximation. In absence of interactions, electron density modulations, in-plane fields, and Fermi surface anisotropy we obtain a quadratic negative magnetoresistance in the weak field limit.Comment: 12 pages, Latex, no figures, Nordita repor

A Review of Controlling Motivational Strategies from a Self-Determination Theory Perspective: Implications for Sports Coaches

The aim of this paper is to present a preliminary taxonomy of six controlling strategies, primarily based on the parental and educational literatures, which we believe are employed by coaches in sport contexts. Research in the sport and physical education literature has primarily focused on coaches’ autonomysupportive behaviours. Surprisingly, there has been very little research on the use of controlling strategies. A brief overview of the research which delineates each proposed strategy is presented, as are examples of the potential manifestation of the behaviours associated with each strategy in the context of sports coaching. In line with self-determination theory (Deci & Ryan, 1985; Ryan & Deci, 2002), we propose that coach behaviours employed to pressure or control athletes have the potential to thwart athletes’ feelings of autonomy, competence,and relatedness, which, in turn, undermine athletes’ self-determined motivation and contribute to the development of controlled motives. When athletes feel pressured to behave in a certain way, a variety of negative consequences are expected to ensue which are to the detriment of the athletes’ well-being. The purpose of this paper is to raise awareness and interest in the darker side of sport participation and to offer suggestions for future research in this area