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661.
This investigation evaluated the new National Collegiate Athletic Association model of heat acclimatization for football players using physiological, psychological, fluid balance, anthropometric, and nutritional variables. Eleven football players (20 +/- 1 year, 1.88 +/- 0.05 m, and 115.36 +/- 18.85 kg) from a Division I football team were observed for the first 8 days of preseason practices. Measurements such as heart rate and gastrointestinal temperature (T(GI)) via telemetric sensor were taken before, 3 times during, and after practice daily. An average 1.39-kg (1.2%) decrease of body mass occurred from prepractice to postpractice (p < 0.01). Consistent with mild body mass losses, urinary indices of hydration status (i.e., color, specific gravity, and osmolality) indicated mild fluid deficits. A significant increase (p < 0.05) from pre- to postpractice was observed in urine color and urine specific gravity, but chronic hypohydration over the 8 days was not noted. The Environmental Symptoms Questionnaire (ESQ) postpractice score was significantly higher (p < 0.05) than the prepractice score was, but averages did not differ across practice days. There was no difference in postpractice T(GI) measurements across days (p < 0.05). Heart rate, T(GI), and ESQ measurements indicated that football players experienced gradual heat acclimatization and enhanced heat tolerance, despite progressive increases of exercise variables, clothing, and environmental stressors.  相似文献   
662.
663.

Background  

Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants for the treatment of depression in patients with Parkinson's Disease (PD) but data on their efficacy are controversial.  相似文献   
664.
Protist diversity is currently a much debated issue in eukaryotic microbiology. Recent evidence suggests that morphological and genetic diversity might be decoupled in some groups of protists, including ciliates, and that these organisms might be much more diverse than their morphology implies. We sought to assess the genetic and morphological diversity of Carchesium polypinum, a widely distributed peritrich ciliate. The mitochondrial marker cytochrome c oxidase subunit I and the nuclear small subunit ribosomal RNA were used to examine genetic diversity. For the morphological assessment, live microscopy and Protargol staining were used. The mitochondrial marker revealed six robust, deeply diverging, and strongly supported clades, while the nuclear gene was congruent for three of these clades. There were no major differences among individuals from the different clades in any of the morphological features examined. Thus, the underlying genetic diversity in C. polypinum is greater than what its morphology suggests, indicating that morphology and genetics are not congruent in this organism. Furthermore, because the clades identified by the mitochondrial marker are so genetically diverse and are confirmed by a conserved nuclear marker in at least three cases, we propose that C. polypinum be designated as a "cryptic species complex." Our results provide another example where species diversity can be underestimated in microbial eukaryotes when using only morphological criteria to estimate species richness.  相似文献   
665.
The Balkan Botanic Garden of Kroussia (BBGK) is dedicated to the ex situ conservation of native plants of Greece and the Balkans. The BBGK has formulated a conservation strategy for the collection of wild plant material for propagation, prioritizing mainly the endemic, rare, endangered, threatened and vulnerable plants of Europe found in different regions of Greece. Its aim is to contribute to the implementation of Target 8 of the Global and European Strategies for Plant Conservation at local, regional and international scales. In order to (i) define the ecological profile of the in situ requirements preferred and/or tolerated by each selected species, (ii) develop rapid and effective species-specific propagation protocols, and (iii) improve the cultivation of species of conservation concern in BBGK’s nurseries and ex situ conservation sections, geographical coordinates and in situ collection data obtained for each taxon were imported into a Geographic Information System environment (GIS). This information was then linked with several digital GIS thematic layers, including topographic, geological, edaphic, climatic, precipitation and temperature data derived from digital databases. Based on this approach, sexual and asexual propagation of plants from the Ionian Islands were conducted and rapid and effective baseline protocols were developed for 29 taxa (species and subspecies); four are presented here in detail and species-specific ex situ propagation and cultivation guidelines are given. Most of the taxa originating from the Ionian Islands were propagated by cuttings (55.2%) or seeds (34.5%), while the rest were propagated by root division at a rate from 1.7 to 2. The first round of propagation achieved a success rate ranging from 15 to 50% for 3 taxa, from 60 to 80% for 8 taxa and from more than 80 to 100% for 16 taxa, while the ex situ cultivation of the wild and propagated plant material has, so far, been successful. The application of GIS exemplified here presents a sensible and invaluable tool with a broad-scale potential in enhancing the prospects of the ex situ conservation of priority species collected from diverse environmental conditions in man-made habitats such as botanic gardens.  相似文献   
666.
Reinforcement learning in neural networks requires a mechanism for exploring new network states in response to a single, nonspecific reward signal. Existing models have introduced synaptic or neuronal noise to drive this exploration. However, those types of noise tend to almost average out—precluding or significantly hindering learning —when coding in neuronal populations or by mean firing rates is considered. Furthermore, careful tuning is required to find the elusive balance between the often conflicting demands of speed and reliability of learning. Here we show that there is in fact no need to rely on intrinsic noise. Instead, ongoing synaptic plasticity triggered by the naturally occurring online sampling of a stimulus out of an entire stimulus set produces enough fluctuations in the synaptic efficacies for successful learning. By combining stimulus sampling with reward attenuation, we demonstrate that a simple Hebbian-like learning rule yields the performance that is very close to that of primates on visuomotor association tasks. In contrast, learning rules based on intrinsic noise (node and weight perturbation) are markedly slower. Furthermore, the performance advantage of our approach persists for more complex tasks and network architectures. We suggest that stimulus sampling and reward attenuation are two key components of a framework by which any single-cell supervised learning rule can be converted into a reinforcement learning rule for networks without requiring any intrinsic noise source. This work was supported by the Swiss National Science Foundation grant K-32K0-118084.  相似文献   
667.
In this study, we investigate the interplay between Ku, a central non‐homologous end‐joining component, and the Mre11–Rad50–Xrs2 (MRX) complex and Sae2, end‐processing factors crucial for initiating 5′‐3′ resection of double‐strand break (DSB) ends. We show that in the absence of end protection by Ku, the requirement for the MRX complex is bypassed and resection is executed by Exo1. In contrast, both the Exo1 and Sgs1 resection pathways contribute to DSB processing in the absence of Ku and Sae2 or when the MRX complex is intact, but functionally compromised by elimination of the Mre11 nuclease activity. The ionizing radiation sensitivity of a mutant defective for extensive resection (exo1Δ sgs1Δ) cannot be suppressed by the yku70Δ mutation, indicating that Ku suppression is specific to the initiation of resection. We provide evidence that replication‐associated DSBs need to be processed by Sae2 for repair by homologous recombination unless Ku is absent. Finally, we show that the presence of Ku exacerbates DNA end‐processing defects established in the sae2Δ sgs1Δ mutant, leading to its lethality.  相似文献   
668.
hyplex®-MBL ID Multiplex PCR-ELISA, a novel method for identifying metallo-β-lactamase genes directly in clinical specimens, was evaluated using a consecutive collection of 326 samples from three hospitals in Greece characterized by high prevalence of VIM producers. The method exhibited high sensitivity (98.0%) and specificity (98.6%) and was proven reliable in detecting blaVIM genes in blood, urine, pus, and sputum samples that, as confirmed by conventional methods, contained various VIM-producing species. Future multicenter studies should be considered for the thorough evaluation of this method and its potential diagnostic utility.  相似文献   
669.
The development of high-oleate soybean germplasm is hindered by the lack of knowledge of the genetic factors controlling oleate phenotypic variation. In the present study, several candidate genes implicated in oleate biosynthesis were mapped and their cosegregation with oleate, linoleate and linolenate quantitative trait loci (QTLs) was investigated. FAD2-2C, a previously described ω-6 desaturase isoform, was localized on linkage group E; whereas, a novel FAD2-2 isoform, designated as FAD2-2D, mapped on linkage group N. In addition, two isoforms were identified for the aminoalcoholphosphotransferase-encoding GmAAPT1 gene, denoted AAPT1a and AAPT1b. A database query suggested that only one functional copy of the FAD6 gene, encoding a plastid localized ω-6 desaturase, exists in the soybean genome. AAPT1a and FAD6 mapped on linkage group D1b, 23.40 cM apart. Linolenate QTLs with minor effects were identified near the FAD6 and AAPT1a markers in two segregating populations. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
670.
Complement dysregulation has been documented in adults with COVID-19 and implicated in relevant pediatric inflammatory responses against SARS-CoV-2. We propose that signatures of complement missense coding SNPs associated with dysregulation could also be identified in children with multisystem inflammatory syndrome (MIS-C). We investigated 71 pediatric patients with RT-PCR validated SARS-CoV-2 hospitalized in pediatric COVID-19 care units (November 2020–March 2021) in three major groups. Seven (7) patients suffered from MIS-C (MIS-C group), 32 suffered from COVID-19 and were hospitalized (admitted group), whereas 32 suffered from COVID-19, but were sent home. All patients survived and were genotyped for variations in the C3, C5, CFB, CFD, CFH, CFHR1, CFI, CD46, CD55, MASP1, MASP2, MBL2, COLEC11, FCN1, and FCN3 genes. Upon evaluation of the missense coding SNP distribution patterns along the three study groups, we noticed similarities, but also considerably increased frequencies of the alternative pathway (AP) associated with SNPs rs12614 CFB, rs1061170, and rs1065489 CFH in the MIS-C patients. Our analysis suggests that the corresponding substitutions potentially reduce the C3b-inactivation efficiency and promote slower and weaker AP C3bBb pre-convertase assembly on virions. Under these circumstances, the complement AP opsonization capacity may be impaired, leading to compromised immune clearance and systemic inflammation in the MIS-C syndrome.  相似文献   
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