309 research outputs found

    Sport psychologists’ experiences of organizational stressors

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    This study extends stress research by exploring sport psychologists’ experiences of organizational stressors. Twelve accredited sport psychologists (6 academics and 6 practitioners) were interviewed regarding their experiences of organizational stress within their jobs. Content analysis involved categorizing the demands associated primarily and directly with their occupation under one of the following general dimensions: factors intrinsic to sport psychology, roles in the organization, sport relationships and interpersonal demands, career and performance development issues, and organizational structure and climate of the profession. A frequency analysis revealed that academics (ΣAOS = 201) experienced more organizational stressors than practitioners (ΣPOS = 168). These findings indicate that sport psychologists experience a wide variety of organizational stressors across different roles, some of which parallel those found previously in other professions. The practical implications for the management of stress for sport psychologists are discussed

    Relationships between wearer assessment and the instrumental measurement of the handle and prickle of knitted wool fabrics

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    The relationships between wearer-assessed comfort and objectively measured comfort and handle parameters were investigated using 19 pure wool single jersey garments made of single ply yarns. Wearer trials were used to determine prickle discomfort, and whether wearers “liked” the garments. Fabrics then were objectively evaluated using the Wool HandleMeter, which measures seven primary handle attributes; and the Wool ComfortMeter (WCM), to predict a wearer\u27s perception of fabric-evoked prickle. Wearer responses and the relationships within and between objective measurements and the effect of fibre, yarn and fabrics attributes were analysed by general linear modelling. Mean fibre diameter, fibre diameter coefficient of variation, yarn count, fabric thickness, fabric density, fabric mass per unit area and decatising affected one or more handle parameters. The best model for predicting wearer prickle discomfort accounted for 90.9% of the variance and included only terms for the WCM and WCM2. The WCM was a good predictor whereas mean fibre diameter was a poor predictor of whether wearers “liked” garments. Wearer assessment of prickle and whether or not wearers “liked” fabrics were independent of fabric handle assessment. The results indicate that the handle and comfort properties of lightweight, wool jersey fabrics can be quantified accurately using the Wool HandleMeter and the Wool ComfortMeter. For fabric handle, fibre and yarn characteristics were less important than changes in the properties of the fabric

    Ultrafine wools: comfort and handle properties for next-to-skin knitwear and manufacturing performance

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    This study aimed to quantify the skin comfort and handle properties of a range of wool fabrics produced from ultrafine wool (13.7–15.1 µm) and in doing so determine if differences in fiber diameter and staple crimp frequency (5.3–7.1 crimps/cm) were important in these properties. The fabrics were evaluated using a range of subjective and objective measurement techniques, including the Wool ComfortMeter, the Wool HandleMeter and in wearer trials. This work indicated that single jersey fabrics made from ultrafine wool are approaching the limit of objective and subjective evaluation of next-to-skin comfort. The results from the Wool ComfortMeter, Wool HandleMeter and the wearer trial show that there were no significant effects that can be attributed to wool staple crimp (fiber curvature) in these ultrafine wool fabrics. The work also demonstrated a difference in the manufacturing response when knitted fabric made from wools of different fiber diameter (13.7–23.7 µm), and using yarns of the same count, resulted in a progressively higher fabric mass per unit area as mean fiber diameter was progressively reduced

    Ancient chloroplast and nuclear genomes provide insights into the evolutionary history of quinoa (chenopodium quinoa willd.)

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    Quinoa (Chenopodium quinoa), an important crop for the global food security, was domesticated in the Andean highlands of South America about 7,000 years ago, where wild relatives still grow today. Archaeological studies have reported quinoa remains dating back to 4,000 years before present, but the ancient genetic diversity remains uncharacterised. Recent sequencing studies of the quinoa nuclear genome suggested domestication took place independently in highland and coastal environments. However, the origin and exact timing of domestication, and the genomic relationships among the tetraploid relatives (C. hircinumand C. berlandieri) of quinoa are not fully understood. Here, we report the nuclear and chloroplast genome sequences of four ~1,400 years old archaeological samples of C. quinoa from the highlands of northern Argentina. Phylogenetic analyses show thatwild, weedy and cultivated accessions from different species cluster in a monophyletic clade, indicative of historical hybridisation of closely related tetraploid species of Chenopodium. Two of the identified chloroplast haplogroups in the ancient samples appear to be absent from modern quinoa accessions, indicating a genetic bottleneck in the recent past. Further, sequence alignment to the nuclear and chloroplast reference genomes of C. quinoa identified a large number of nucleotide polymorphisms in the ancient specimens, providing resources for further analysis of domestication history as well as genetic changes in loci of breeding value.Fil: Estrada Santamarina, Oscar. University of Adelaide; AustraliaFil: Breen, James. University of Adelaide; AustraliaFil: Mitchell, Kieren J.. University of Adelaide; AustraliaFil: Babot, Maria del Pilar. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn. Instituto Superior de Estudios Sociales. Universidad Nacional de TucumĂĄn. Instituto Superior de Estudios Sociales; ArgentinaFil: Hocsman, SalomĂłn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - TucumĂĄn. Instituto Superior de Estudios Sociales. Universidad Nacional de TucumĂĄn. Instituto Superior de Estudios Sociales; ArgentinaFil: Jarvis, David. University Brigham Young; Estados UnidosFil: Tester, David. King Abdullah University of Science and Technology; Arabia SauditaFil: Cooper, Alan. University of Adelaide; AustraliaPlant and Animal Genome Conference XXVIISan DiegoEstados UnidosInternational Plant and Animal Genome Conferenc

    Detection of Harmful Algal Blooms Using Photopigments and Absorption Signatures: A Case Study of the Florida Red Tide Dinoflagellate, Gymnodinium breve

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    The utility of photopigments and absorption signatures to detect and enumerate the red tide dinoflagellate, Gymnodinium breve, was evaluated in laboratory cultures and in natural assemblages. The carotenoid, gyroxanthindiester, was an adequate biomarker for G. breve biomass; water‐column concentrations corresponded with cell standing crops and chlorophyll a concentrations during bloom events in Sarasota Bay, Florida. Unlike other carotenoids, the relative abundance of gyroxanthin‐diester did not change throughout a range of physiological states in culture and the gyroxanthin‐diester: chlorophyll a ratio exhibited little variability in a natural assemblage during bloom senescence. Stepwise discriminant analysis indicated that wavelengths indicative of in vivo absorption by accessory chlorophylls and carotenoids could correctly discern spectra of the fucoxanthin‐containing G. breve from spectra of peridinin‐containing dinoflagellates, a diatom, a haptophyte, and a prasinophyte. With the use of a similarity algorithm, the increasing contribution of G. breve was discerned in absorption spectra (and corresponding fourth‐derivative plots) for hypothetical mixed assemblages. However, the absorption properties of chlorophyll c‐containing algae vary little among taxa and it is difficult to discern the contribution of accessory chlorophylls and carotenoids caused by cell packaging. Therefore, the use of absorption spectra alone may not identify the contribution of a chlorophyll c‐containing taxon to the composite spectrum of a mixed assemblage. This difficulty in distinguishing among spectra can be minimized by using the similarity algorithm in conjunction with fourth‐derivative analysis

    Novel Timothy Syndrome Mutation Leading to Increase in CACNA1C Window Current

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    Background Timothy syndrome (TS) is a rare multisystem genetic disorder characterized by a myriad of abnormalities, including QT prolongation, syndactyly, and neurologic symptoms. The predominant genetic causes are recurrent de novo missense mutations in exon 8/8A of the CACNA1C-encoded L-type calcium channel; however, some cases remain genetically elusive. Objective The purpose of this study was to identify the genetic cause of TS in a patient who did not harbor a CACNA1C mutation in exon 8/A, and was negative for all other plausible genetic substrates. Methods Diagnostic exome sequencing was used to identify the genetic substrate responsible for our case of TS. The identified mutation was characterized using whole-cell patch-clamp technique, and the results of these analyses were modeled using a modified Luo–Rudy dynamic model to determine the effects on the cardiac action potential. Results Whole exome sequencing revealed a novel CACNA1C mutation, p.Ile1166Thr, in a young male with diagnosed TS. Functional electrophysiologic analysis identified a novel mechanism of TS-mediated disease, with an overall loss of current density and a gain-of-function shift in activation, leading to an increased window current. Modeling studies of this variant predicted prolongation of the action potential as well as the development of spontaneous early afterdepolarizations. Conclusion Through expanded whole exome sequencing, we identified a novel genetic substrate for TS, p.Ile1166Thr-CACNA1C. Electrophysiologic experiments combined with modeling studies have identified a novel TS mechanism through increased window current. Therefore, expanded genetic testing in cases of TS to the entire CACNA1C coding region, if initial targeted testing is negative, may be warranted

    nduction and Characterization of Mutations Related to Dwarf Habit in Hardy Hibiscus (Muenchhusia section)

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    Hybrids between various species of Hibiscus in the Muenchhusia section are popular in commercial markets due to their colorful, floriferous blooms. However, many commercial cultivars are too vigorous for use in smaller garden spaces and often have only a few flowers in bloom. Stable, heritable mutants exhibiting dwarf stature and better branching architecture will be valuable to the commercial production of hardy Hibiscus. The goal of this project was to induce stable, heritable mutations using ethyl methanesulfonate that result in increased branching and a dwarf compact phenotype and introgress the compact phenotypes into lines of hardy Hibiscus to generate a series of diverse compact cultivars for use in commercial markets. Multiple mutations associated with dwarf, compact phenotypes were successfully induced. Hybridizations were made between M2 plants displaying a dwarf phenotype and hybrids developed through conventional breeding that do not possess the dwarf mutation in their background to develop diverse selections of dwarf plants. Inheritance patterns of the dwarf genes were determined through the segregation ratios of the dwarf phenotype in the F1 and F2 generations of these hybrids. Compared with wild-type progeny, dwarf progeny had shorter internode lengths and a greater number of primary branches

    Immune evasion versus recovery after acute hepatitis C virus infection from a shared source

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    Acute infection with hepatitis C virus (HCV) rarely is identified, and hence, the determinants of spontaneous resolution versus chronicity remain incompletely understood. In particular, because of the retrospective nature and unknown source of infection in most human studies, direct evidence for emergence of escape mutations in immunodominant major histocompatibility complex class I–restricted epitopes leading to immune evasion is extremely limited. In two patients infected accidentally with an identical HCV strain but who developed divergent outcomes, the total lack of HCV-specific CD4+ T cells in conjunction with vigorous CD8+ T cells that targeted a single epitope in one patient was associated with mutational escape and viral persistence. Statistical evidence for positive Darwinian selective pressure against an immunodominant epitope is presented. Wild-type cytotoxic T lymphocytes persisted even after the cognate antigen was no longer present

    Classification and Identification of Pfiesteria and Pfiesteria-Like Species

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    Dinoflagellates can be classified both botanically and zoologically; however, they are typically put in the botanical division Pyrrhophyta. As a group they appear most related to the protistan ciliates and apicomplexans at the ultrastructure level. Within the Pyrrhophyta are both unarmored and armored forms of the dominant, motile flagellated stage. Unarmored dinoflagellates do not have thecal or wall plates arranged in specific series, whereas armored species have plates that vary in thickness but are specific in number and arrangement. In armored dinoflagellates, the plate pattern and tabulation is a diagnostic character at the family, subfamily, and even genus levels. In most cases, the molecular characterization of dinoflagellates confirms the taxonomy on the basis of external morphology; this has been demonstrated for several groups. Together, both genetic and morphological criteria are becoming increasingly important for the characterization, separation, and identification of dinoflagellates species. Pfiesteria and Pfiesteria-like species are thinly armored forms with motile dinospore stages characterized by their distinct plate formulae. Pfiesteria piscicida is the best-known member of the genus; however, there is at least one other species. Other genetically and morphologically related genera, now grouped under the common names of Lucy, Shepherd\u27s crook, and cryptoperidiniopsoid, are being studied and described in separate works. All these other heterotrophic dinoflagellate groups, many of which are thought to be benign, co-occur in estuarine waters where Pfiesteria has been found
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