7,192 research outputs found

    Spatial Variation in Erosion Rates in Mars Equatorial Regions Inferred from Ejecta Retention of 1-3 Km Diameter Craters

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    The modification of impact craters has long been used to infer the geomorphic forcing on Mars [1], as well as estimate the spatial and temporal variability of this erosion and gradation [e.g., 2]. Here, we studied the population of small primary craters (1-3 km) to understand differences in ejecta retention across equatorial Mars. Specifically, we evaluated whether craters in our study population had observable ejecta deposits (defined on the basis of distinct tone or texture with respect to their surroundings).This is a proxy for the resurfacing rate because only relatively fresh craters retain their ejecta deposits. More broadly, this is part of a larger project we are undertaking [3] to examine crater morphometry and other characteristics from CTX-derived digital terrain models (DTMs), augmented by qualitative observations

    Long-term biopermanence of ceramides, cholesteryl esters, and ether-linked triglycerides with very-long-chain PUFA in the cadmium-damaged testis

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    Cadmium is known to harm rat testis by causing the dose-dependent apoptotic or necrotic death of seminiferous epithelium cells. Here we investigated how this affects the lipids with long-chain (C18-C22) and very-long-chain (C24-C32) polyunsaturated fatty acids (VLCPUFA) typical of spermatogenic and Sertoli cells. A severe acute inflammatory reaction resulted from the massive necrotic death of these cells two days after a single high (4 mg/kg) dose of CdCl2. This led to the conversion of most testicular glycerophospholipids to diradylglycerols (DRG) and free fatty acids (FFA) and of most sphingomyelins to ceramides (Cer). By day 30 the testis weight had decreased three fold. The DRG and FFA had been metabolized but, unexpectedly, ceramides persisted. Also slow to disappear were VLCPUFA-containing triacylglycerols from former germ cells and ether-linked triglycerides and cholesteryl esters (CE) from former Sertoli cells. Similar results were observed 30 and 45 days after administering repeated small non proinflammatory CdCl2doses (1 mg/kg). At day 30 after both treatments, an amorphous material replaced the original seminiferous tubules and testicular macrophages populated the interstitium. Species of CE and etherlinked triglycerides containing fatty acids other than VLCPUFA steadily accumulated in the irreversibly damaged testis, a manifestation of the activity of phagocytic cells. The long-term permanence of original VLCPUFA-containing neutral lipids, especially ceramides, indicates that these cells were slow to clear out the acellular material contained in seminiferous tubules, pointing to a form of silent chronic inflammation as an additional outcome of the multifactorial commotion caused in the testis by experimentally administered cadmium.Fil: Zanetti, Samanta Romina. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET Bahía Blanca. Instituto de Investigaciones Bioquímicas Bahía Blanca (i); ArgentinaFil: Aveldaño, Marta I.. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET Bahía Blanca. Instituto de Investigaciones Bioquímicas Bahía Blanca (i); Argentin

    MRSA screening by the Xpert MRSA PCR assay: pooling samples of the nose, throat, and groin increases the sensitivity of detection without increasing the laboratory costs.

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    The performance of the Xpert MRSA polymerase chain reaction (PCR) assay on pooled nose, groin, and throat swabs (three nylon flocked eSwabs into one tube) was compared to culture by analyzing 5,546 samples. The sensitivity [0.78, 95 % confidence interval (CI) 0.73-0.82] and specificity (0.99, 95 % CI 0.98-0.99) were similar to the results from published studies on separated nose or other specimens. Thus, the performance of the Xpert MRSA assay was not affected by pooling the three specimens into one assay, allowing a higher detection rate without increasing laboratory costs, as compared to nose samples alone

    MRSA screening by the Xpert MRSA PCR assay: pooling samples of the nose, throat, and groin increases the sensitivity of detection without increasing the laboratory costs

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    The performance of the Xpert MRSA polymerase chain reaction (PCR) assay on pooled nose, groin, and throat swabs (three nylon flocked eSwabs into one tube) was compared to culture by analyzing 5,546 samples. The sensitivity [0.78, 95% confidence interval (CI) 0.73-0.82] and specificity (0.99, 95% CI 0.98-0.99) were similar to the results from published studies on separated nose or other specimens. Thus, the performance of the Xpert MRSA assay was not affected by pooling the three specimens into one assay, allowing a higher detection rate without increasing laboratory costs, as compared to nose samples alon

    In ovulo embryo culture of stenospermocarpic grapes

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    Ovules of 14 seedless cultivars, collected 41-49 d after anthesis, were excised and in vitro cultured on 2 different media: NN + 1 µM GA3 + 10 µM IAA and NN + 1 µM GA3 + 20 µM IAA + 2 g/l activated charcoal. Plant development occurred at variable rates; the best percentages were found in Flame Seedless, Perlon, Imperatrice, Carina, Perlette and Ruby Seedless. Genotype resulted to be the main factor affecting ovule response to culture, but also the medium and the interaction genotype x medium influenced it. The addition of 2 g/l activated charcoal to the medium, tested on the cv. Perlette, and the type of added auxin (IBA, IAA, NAA), tested on the cvs Perlette and Sultanina, enhanced plantlet development

    Traditional free-weight vs. variable resistance training applied to elite young soccer players during a short preseason: effects on strength, speed, and power performance

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    Maximizing the neuromuscular capacities of players is a critical challenge during short soccer preseasons. This study compared the effects of two strength-power training regimes, on the strength, speed, and power performance of elite young soccer players during a 4-week preseason. Twenty-five under-20 players from the same club were pair-matched in two training groups as follows: traditional training group (TTG) (n=13), athletes performed half-squat (HS) and jump-squat (JS) exercises as traditionally prescribed; and EB group (EBG) (n=12), athletes performed HS and JS with EB attached to the barbell. Vertical jump height, 20-m sprint velocity, change-of-direction (COD) speed, HS and JS power, and one-repetition maximum (1RM) in the HS were assessed pre, post 2-week, and post 4-week of training. An ANOVA two-way with repeated measures was used to assess the effects of both training protocols over the experimental period. Both strategies were effective for significantly improving HS and JS power (effect sizes [ES] 1.00 - 1.77), HS 1RM (ES = 1.68 and 1.51 for TTG and EBG, respectively), vertical jumping ability (ES 0.37 - 0.65), and COD speed (ES = 0.81 and 0.39 for TTG and EBG, respectively), when comparing pre- and post-measures. In contrast, both TTG and EBG failed to increase 20-m sprint velocity (ES ranging between -0.54 and 0.23). In conclusion, both training schemes were able to improve the strength and power performance, but not the sprint capacity of young soccer players. To accelerate strength gains over very-short time periods (i.e., 2-week), variable resistance training may be advantageous. Conversely, to optimize power adaptations in ballistic exercises across a similar time period, traditional FW training may be preferred

    Systemic behavior of a Brazilian municipality whose economy is based on agricultural commodities.

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    The municipality evaluated is São Gabriel do Oeste, located in the state of Mato Grosso do Sul, Brazil. In the 1960's the region was occupied by migrants from southern Brazil who have converted native vegetation (savanna) into extensive cattle and monocrops (coffee, cotton, soybeans and corn, successively), and more recently intensive swine was introduced. The following emergy indicators were calculated for the current municipal situation: Renewability (%R): 8%; Emergy yield ratio (EYR): 14; Emergy investment ratio (EIR): 0.08; Environmental loading ratio (ELR): 11; Emergy exchange ratio (EER): 13 and Transformity of the commodities: 8x105seJ.J-1. The very low %R and high environmental pressure (ELR) signalize that the municipality's economy is highly dependent on external inputs. Above all, there is a high loss of system internal stocks (soil) and the high EYR obtained is directly related to this predatory land use. The emergy value of the soil loss is 83% of the total emergy, which is an environmental imbalanced situation. The main land use in São Gabriel do Oeste, accounting for 39% of the territory, is extensive cattle farming that demands few agricultural inputs, what explains the very low EIR. The EER shows that the rural area is subsidizing urban economies that import products from the study area. The real value of the agricultural products should be 13 times the market value of such commodities to be considered as a fair trade. The inclusion of soil loss as a negative externality shows that (in economic terms) the amount of soil lost by erosion and leaching (4,149x106 emUSD.year-1) corresponds to 46% of the total production monetary value (9,018x106 emUSD.year-1). The emergy diagnosis shows that the business model established for commodities producers is highly dependent on the external market, which does not remunerate the imported resources accordingly to its real value. To settle this situation, a dialogue between farmers, consumers and authorities should be established. The latter two should involve not only local representatives as well as players of the importing countries.BIWAES 2015

    Effects of a resistance training intervention on the strength-deficit of elite young soccer players

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    The aim of this study was to examine the effects of a traditional resistance training scheme on the relative strength (RS), relative peak-force (RPF), strength deficit (SDef), and vertical jump and sprint abilities in elite young soccer players. Thirty-five under-20 soccer players from two professional clubs were assessed before and after a 4-week competitive period. One team performed 12 sessions of a structured resistance training program and the other maintained their regular soccer-specific training and competitive routines. The resistance training program consisted of performing half-squat and jump squat exercises at distinct percentages of the one-repetition maximum. Both teams performed pre- and post-measurements in the following order: (1) countermovement jump (CMJ), (2) 20-m sprint, and (3) half-squat one-repetition maximum to determine the RS, RPF, and SDef. A two-way analysis of variance was used to test for group x time interaction among variables. Effect sizes (ES) and 95% confidence intervals (CI) were also calculated. Group x time interactions were demonstrated for RS ([ES [95%CI] = 1.21 [0.57; 1.85], P = 0.001), RPF (ES [95%CI] = 1.18 [0.52; 1.80], P = 0.001), SDef (ES [95%CI] = 0.86 [0.01; 1.71], P = 0.04), and CMJ (ES [95%CI] = 0.64 [0.28; 0.99], P = 0.001); whereas a non-significant interaction was observed for 20-m sprint performance (ES [95%CI] = 0.02 [-0.32; 0.36], P = 0.85). Traditional strength-power oriented training resulted in improved maximum strength performance and CMJ ability but, paradoxically, increased the SDef. As a consequence, stronger athletes are not necessarily able to use greater percentages of their peak-force against relatively lighter loads

    Potential signals of natural selection in the top risk loci for coronary artery disease: 9p21 and 10q11

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    Background: Coronary artery disease (CAD) is a complex disease and the leading cause of death in the world. Populations of different ancestry do not always share the same risk markers. Natural selective processes may be the cause of some of the population differences detected for specific risk mutations. Objective: In this study, 384 single nucleotide polymorphisms (SNPs) located in four genomic regions associated with CAD (1p13, 1q41, 9p21 and 10q11) are analysed in a set of 19 populations from Europe, Middle East and North Africa and also in Asian and African samples from the 1000 Genomes Project. The aim of this survey is to explore for the first time whether the genetic variability in these genomic regions is better explained by demography or by natural selection. Results: The results indicate significant differences in the structure of genetic variation and in the LD patterns among populations that probably explain the population disparities found in markers of susceptibility to CAD. Conclusions: The results are consistent with potential signature of positive selection in the 9p21 region and of balancing selection in the 9p21 and 10q11. Specifically, in Europe three CAD risk markers in the 9p21 region (rs9632884, rs1537371 and rs1333042) show consistent signals of positive selection. The results of this study are consistent with a potential selective role of CAD in the configuration of genetic diversity in current human populations
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