395 research outputs found

    Mentoring Relationships and Programs: Applications to the Forensics Community

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    Mentoring activities and programs have gained increasing attention and endorsement in a variety of business and academic areas. This paper proceeded with the premise that mentoring may possess untapped potential for the forensic community. Starting with a survey of experienced and novice coaches to assess the existence of and attitudes toward mentoring activities, the paper then moves to conclusions and recommendations for the expanded use of mentoring as a method to advance or promote our forensic coaches and judges

    Ischemic Preconditioning Blunts Loss of Knee Extensor Torque Complexity with Fatigue

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    Introduction: Neuromuscular fatigue reduces the temporal structure, or complexity, of muscle torque output, purportedly through an effect on motor unit behaviour. Ischaemic pre-conditioning (IPC), an emerging ergogenic aid, has been demonstrated to have a potent effect on muscular output and endurance. We therefore tested the hypothesis that IPC would attenuate the fatigueinduced loss of muscle torque complexity. Methods: Ten healthy participants (6 male/4 female) performed intermittent isometric knee extension contractions (6 s contraction, 4 s rest) to task failure at 40% maximal voluntary contraction (MVC). Contractions were preceded by either IPC (three bouts of 5 minutes proximal thigh occlusion at 225 mmHg, interspersed with 5 minutes rest) or SHAM (as IPC, but occlusion at only 20 mmHg) treatments. Torque and EMG signals were sampled continuously. Complexity and fractal scaling were quantified using approximate entropy (ApEn) and the detrended fluctuation analysis (DFA) α scaling exponent. Muscle oxygen consumption (mV̇O2_2) was determined using near-infrared spectroscopy. Results: IPC increased time to task failure by 43 ± 13% (mean ± SEM, P = 0.047). Complexity decreased in both trials (decreased ApEn, increased DFA α; both P < 0.001), though the rate of decrease was significantly lower following IPC (ApEn, –0.2 ± 0.1 vs. –0.4 ± 0.1, P = 0.013; DFA α, 0.2 ± 0.1 vs. 0.3 ± 0.1, P = 0.037). Similarly, the rates of increase in EMG amplitude (P = 0.022) and mV̇O2_2 (P = 0.043) were significantly slower following IPC. Conclusion: These results suggest the ergogenic effect of IPC observed here is of neural origin and accounts for the slowing of the rates of change in torque complexity, EMG amplitude and muscle oxygen consumption as fatigue develops

    Effects of Contrasting Word Retrieval Treatments in Phonologic and Semantic Anomia

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    This investigation was designed to elucidate the effects of repeated practice treatment on sound production in AOS and to determine if the addition of rate/rhythm control to treatment provided further benefits. A combined multiple baseline and ABCA design was employed with five speakers with chronic AOS and aphasia. Accuracy of articulation of target items in probes served as the dependent measure. Substantial improvements in articulation were associated with repeated practice treatment for three of the participants, with minimal gains observed for the remaining two participants. Rate/rhythm control resulted in additional gains for two of the participants

    Contrasting Effects of Errorless Naming Treatment and Gestural Facilitation for Word Retrieval in Aphasia

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    Purpose- We compared the effects of two treatments for aphasic word retrieval impairments, errorless naming treatment (ENT) and gestural facilitation of naming (GES), within the same individuals, anticipating that the use of gesture would enhance the effect of treatment over errorless treatment alone. In addition to picture naming, we evaluated results for other outcome measures that were largely untested in earlier ENT studies. Methods- In a single participant crossover treatment design, we examined the effects of ENT and GES in eight individuals with stroke-induced aphasia and word retrieval impairments (three semantic anomia, five phonological anomia) in counterbalanced phases across participants. We evaluated effects of the two treatments for a daily picture naming/gesture production probe measure and in standardised aphasia tests and communication rating scales administered across phases of the experiment. Results- Both treatments led to improvements in naming of trained words (small-to-large effect sizes) in individuals with semantic and phonological anomia. Small generalised naming improvements were noted for three individuals with phonological anomia. GES improved use of corresponding gestures for trained words (large effect sizes). Results were largely maintained at one month post-treatment completion. Increases in scores on standardised aphasia testing also occurred for both ENT and GES training. Discussion- Both ENT and GES led to improvements in naming measures, with no clear difference between treatments. Increased use of gestures following GES provided a potential compensatory means of communication for those who did not improve verbal skills. Both treatments are considered to be effective methods to promote recovery of word retrieval and verbal production skills in individuals with aphasia

    Gene expression in fungi

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    This contribution is based on the four presentations made at the Special Interest Group (SIG) meeting titled Gene Expression in Fungi held during IMC9 in Edinburgh. This overview is independent from other articles published or that will be published by each speaker. In the SIG meeting, basic principles of in vivo animal models for virulence studies were discussed. Infection associated genes of Candida albicans and fungal adaptation to the host was summarized. Azole susceptibility was evaluated as a combined result of several changes in expression of pertinent genes. Gene transfer in fungi, resulting in fungal evolution and gene adaptation to environmental factors, was reported

    Evidence for maintenance of sex determinants but not of sexual stages in red yeasts, a group of early diverged basidiomycetes

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    <p>Abstract</p> <p>Background</p> <p>The red yeasts are an early diverged group of basidiomycetes comprising sexual and asexual species. Sexuality is based on two compatible mating types and sexual identity is determined by <it>MAT </it>loci that encode homeodomain transcription factors, peptide pheromones and their receptors. The objective of the present study was to investigate the presence and integrity of <it>MAT </it>genes throughout the phylogenetic diversity of red yeasts belonging to the order Sporidiobolales.</p> <p>Results</p> <p>We surveyed 18 sexual heterothallic and self-fertile species and 16 asexual species. Functional pheromone receptor homologues (<it>STE3.A1 </it>and <it>STE3.A2</it>) were found in multiple isolates of most of the sexual and asexual species. For each of the two mating types, sequence comparisons with whole-genome data indicated that synteny tended to be conserved along the pheromone receptor region. For the homeodomain transcription factor, likelihood methods suggested that diversifying selection acting on the self/non-self recognition region promotes diversity in sexual species, while rapid evolution seems to be due to relaxed selection in asexual strains.</p> <p>Conclusions</p> <p>The majority of both sexual and asexual species of red yeasts have functional pheromone receptors and homeodomain homologues. This and the frequent existence of asexual strains within sexual species, makes the separation between sexual and asexual species imprecise. Events of loss of sexuality seem to be recent and frequent, but not uniformly distributed within the Sporidiobolales. Loss of sex could promote speciation by fostering the emergence of asexual lineages from an ancestral sexual stock, but does not seem to contribute to the generation of exclusively asexual lineages that persist for a long time.</p

    Light Controls Growth and Development via a Conserved Pathway in the Fungal Kingdom

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    Light inhibits mating and haploid fruiting of the human fungal pathogen Cryptococcus neoformans, but the mechanisms involved were unknown. Two genes controlling light responses were discovered through candidate gene and insertional mutagenesis approaches. Deletion of candidate genes encoding a predicted opsin or phytochrome had no effect on mating, while strains mutated in the white collar 1 homolog gene BWC1 mated equally well in the light or the dark. The predicted Bwc1 protein shares identity with Neurospora crassa WC-1, but lacks the zinc finger DNA binding domain. BWC1 regulates cell fusion and repression of hyphal development after fusion in response to blue light. In addition, bwc1 mutant strains are hypersensitive to ultraviolet light. To identify other components required for responses to light, a novel self-fertile haploid strain was created and subjected to Agrobacterium-mediated insertional mutagenesis. One UV-sensitive mutant that filaments equally well in the light and the dark was identified and found to have an insertion in the BWC2 gene, whose product is structurally similar to N. crassa WC-2. The C. neoformans Bwc1 and Bwc2 proteins interact in the yeast two-hybrid assay. Deletion of BWC1 or BWC2 reduces the virulence of C. neoformans in a murine model of infection; the Bwc1-Bwc2 system thus represents a novel protein complex that influences both development and virulence in a pathogenic fungus. These results demonstrate that a role for blue/UV light in controlling development is an ancient process that predates the divergence of the fungi into the ascomycete and basidiomycete phyla

    The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

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    Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals

    Comparative Genomics of the Mating-Type Loci of the Mushroom Flammulina velutipes Reveals Widespread Synteny and Recent Inversions

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    Mating-type loci of mushroom fungi contain master regulatory genes that control recognition between compatible nuclei, maintenance of compatible nuclei as heterokaryons, and fruiting body development. Regions near mating-type loci in fungi often show adapted recombination, facilitating the generation of novel mating types and reducing the production of self-compatible mating types. Compared to other fungi, mushroom fungi have complex mating-type systems, showing both loci with redundant function (subloci) and subloci with many alleles. The genomic organization of mating-type loci has been solved in very few mushroom species, which complicates proper interpretation of mating-type evolution and use of those genes in breeding programs.We report a complete genetic structure of the mating-type loci from the tetrapolar, edible mushroom Flammulina velutipes mating type A3B3. Two matB3 subloci, matB3a that contains a unique pheromone and matB3b, were mapped 177 Kb apart on scaffold 1. The matA locus of F. velutipes contains three homeodomain genes distributed over 73 Kb distant matA3a and matA3b subloci. The conserved matA region in Agaricales approaches 350 Kb and contains conserved recombination hotspots showing major rearrangements in F. velutipes and Schizophyllum commune. Important evolutionary differences were indicated; separation of the matA subloci in F. velutipes was diverged from the Coprinopsis cinerea arrangement via two large inversions whereas separation in S. commune emerged through transposition of gene clusters.In our study we determined that the Agaricales have very large scale synteny at matA (∼350 Kb) and that this synteny is maintained even when parts of this region are separated through chromosomal rearrangements. Four conserved recombination hotspots allow reshuffling of large fragments of this region. Next to this, it was revealed that large distance subloci can exist in matB as well. Finally, the genes that were linked to specific mating types will serve as molecular markers in breeding
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