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61.
Gil SM Gil J Ruiz F Irazusta A Irazusta J 《Journal of strength and conditioning research / National Strength & Conditioning Association》2007,21(2):438-445
The aim of this study was to establish the anthropometric and physiological profiles of young nonelite soccer players according to their playing position, and to determine their relevance for the selection process. Two hundred forty-one male soccer players who were members of the Getxo Arenas Club (Bizkaia) participated in this study. Players, age 17.31 (+/- 2.64) years, range 14-21 years, were classified into the following groups: forwards (n = 56), midfielders (n = 79), defenders (n = 77), and goalkeepers (n = 29). Anthropometric variables of participants (height, weight, body mass index, 6 skinfolds, 4 diameters, and 3 perimeters) were measured. Also, their somatotype and body composition (weights and percentages of fat, bone, and muscle) were calculated. Participants performed the Astrand test to estimate their absolute and relative VO2max, an endurance test, sprint tests (30 meters flat and 30 meters with 10 cones) and 3 jump tests (squat jump, counter movement jump and drop jump). Forwards were the leanest, presenting the highest percentage of muscle. They were the best performers in all the physiological tests, including endurance, velocity, agility, and power. In contrast, goalkeepers were found to be the tallest and the heaviest players. They also had the largest fat skinfolds and the highest fat percentage, but their aerobic capacity was the lowest. In the selection process, agility and the jump tests were the most discriminating for forwards. In contrast, agility, height, and endurance were the key factors for midfielders. The defenders group was characterized by a lower quantity of fat. Thus, we may conclude that anthropometric and physiological differences exist among soccer players who play in different positions. These differences fit with their different workload in a game. Therefore, training programs should include specific sessions for each positional role. 相似文献
62.
Alvarez Frank Ernesto Carrillo José Antonio Clairambault Jean 《Journal of mathematical biology》2022,85(6-7):1-15
Homeostasis represents the idea that a feature may remain invariant despite changes in some external parameters. We establish a connection between homeostasis and injectivity for reaction network models. In particular, we show that a reaction network cannot exhibit homeostasis if a modified version of the network (which we call homeostasis-associated network) is injective. We provide examples of reaction networks which can or cannot exhibit homeostasis by analyzing the injectivity of their homeostasis-associated networks.
相似文献63.
Background and Aims Many plants produce extrafloral nectar (EFN), and increase production following above-ground herbivory, presumably to attract natural enemies of the herbivores. Below-ground herbivores, alone or in combination with those above ground, may also alter EFN production depending on the specificity of this defence response and the interactions among herbivores mediated through plant defences. To date, however, a lack of manipulative experiments investigating EFN production induced by above- and below-ground herbivory has limited our understanding of how below-ground herbivory mediates indirect plant defences to affect above-ground herbivores and their natural enemies.Methods In a greenhouse experiment, seedlings of tallow tree (Triadica sebifera) were subjected to herbivory by a specialist flea beetle (Bikasha collaris) that naturally co-occurs as foliage-feeding adults and root-feeding larvae. Seedlings were subjected to above-ground adults and/or below-ground larvae herbivory, and EFN production was monitored.Key Results Above- and/or below-ground herbivory significantly increased the percentage of leaves with active nectaries, the volume of EFN and the mass of soluble solids within the nectar. Simultaneous above- and below-ground herbivory induced a higher volume of EFN and mass of soluble solids than below-ground herbivory alone, but highest EFN production was induced by above-ground herbivory when below-ground herbivores were absent.Conclusions The induction of EFN production by below-ground damage suggests that systemic induction underlies some of the EFN response. The strong induction by above-ground herbivory in the absence of below-ground herbivory points to specific induction based on above- and below-ground signals that may be adaptive for this above-ground indirect defence. 相似文献
64.
65.
Catalán V Gómez-Ambrosi J Rodríguez A Ramírez B Silva C Rotellar F Hernández-Lizoain JL Baixauli J Valentí V Pardo F Salvador J Frühbeck G 《The Journal of nutritional biochemistry》2011,22(7):634-641
Background
Obesity is widely recognised as an important risk factor for colorectal cancer (CC).Aim
The study aimed to evaluate the effect of CC on circulating concentrations and gene expression levels of inflammatory and angiogenesis-related factors in human visceral adipose tissue (VAT).Methods
VAT biopsies were obtained from 18 healthy individuals and 11 patients with CC. Real-time polymerase chain reactions were performed to quantify gene expression levels and zymographic analyses were used to determine the activity of matrix metalloproteinases (MMPs).Results
Patients with CC exhibited increased mRNA expression levels of lipocalin-2 (P=.014), osteopontin (P=.027), tumor necrosis factor-α (TNF-α) (P=.016) and chitinase-3 like-1 (P=.006) compared to control subjects in VAT. Gene expression levels of hypoxia-inducible factor-1 α, vascular endothelial growth factor and MMP-2 were significantly higher (P<.05) in VAT of patients with CC. The expression of insulin-like growth factor I, insulin growth factor binding protein 3 and MMP-9 followed the same trend, although no significant differences were reached. The enzymatic activity of MMP-9 was increased (P<.001) in patients with CC. Furthermore, individuals with CC showed increased (P<.05) circulating concentrations of the inflammatory markers interleukin-6, tumour necrosis factor α and hepatocyte growth factor, whereas levels of the anti-inflammatory adipokine adiponectin were decreased (P<.01).Conclusion
These findings represent the first observation that mRNA levels of the novel inflammatory factors lipocalin-2, chitinase-3 like-1 and osteopontin are increased in human VAT of subjects with CC. This observation together with the up-regulation of angiogenic factors suggests that adipokines secreted by VAT may be involved in the development of colon cancer. 相似文献66.
Vegliante MC Royo C Palomero J Salaverria I Balint B Martín-Guerrero I Agirre X Lujambio A Richter J Xargay-Torrent S Bea S Hernandez L Enjuanes A Calasanz MJ Rosenwald A Ott G Roman-Gomez J Prosper F Esteller M Jares P Siebert R Campo E Martín-Subero JI Amador V 《PloS one》2011,6(6):e21382
Recent studies have shown aberrant expression of SOX11 in various types of aggressive B-cell neoplasms. To elucidate the molecular mechanisms leading to such deregulation, we performed a comprehensive SOX11 gene expression and epigenetic study in stem cells, normal hematopoietic cells and different lymphoid neoplasms. We observed that SOX11 expression is associated with unmethylated DNA and presence of activating histone marks (H3K9/14Ac and H3K4me3) in embryonic stem cells and some aggressive B-cell neoplasms. In contrast, adult stem cells, normal hematopoietic cells and other lymphoid neoplasms do not express SOX11. Such repression was associated with silencing histone marks H3K9me2 and H3K27me3. The SOX11 promoter of non-malignant cells was consistently unmethylated whereas lymphoid neoplasms with silenced SOX11 tended to acquire DNA hypermethylation. SOX11 silencing in cell lines was reversed by the histone deacetylase inhibitor SAHA but not by the DNA methyltransferase inhibitor AZA. These data indicate that, although DNA hypermethylation of SOX11 is frequent in lymphoid neoplasms, it seems to be functionally inert, as SOX11 is already silenced in the hematopoietic system. In contrast, the pathogenic role of SOX11 is associated with its de novo expression in some aggressive lymphoid malignancies, which is mediated by a shift from inactivating to activating histone modifications. 相似文献
67.
A framework is developed for constructing a large class of discrete generation, continuous space models of evolving single species populations and finding their bifurcating patterned spatial distributions. Our models involve, in separate stages, the spatial redistribution (through movement laws) and local regulation of the population; and the fundamental properties of these events in a homogeneous environment are found. Emphasis is placed on the interaction of migrating individuals with the existing population through conspecific attraction (or repulsion), as well as on random dispersion. The nature of the competition of these two effects in a linearized scenario is clarified. The bifurcation of stationary spatially patterned population distributions is studied, with special attention given to the role played by that competition.Acknowledgement We gratefully received valuable help through discussions with Hiroshi Matano, Davar Khosnevisan, and Nacho Barradas. Khosnevisan provided us with the background information for Sections 3.3.1 and 3.3.2. Matano provided us with a proof of Lemma 4.4 similar to the one given here. Barradas drew our attention to the relation (2.1). 相似文献
68.
Ramos-Kuri M Carrillo Farga J Zúñiga J Amador Guerrero MT Granados J Estrada FJ 《Human biology; an international record of research》2005,77(3):399-405
We describe the finding of two Mexican patients with a specific 27-bp deletion in the solute carrier family 4 gene (SLC4A1delta27) (also known as the band 3 gene found on chromosome 17q21-q22), characteristic of Southeast Asian ovalocytosis (SAO). The patients were asymptomatic, and the initial diagnosis was made by microscopic observation of the presence of typical stomatocytic ovalocytes. The gene deletion was confirmed by PCR and DNA sequencing. Both patients were heterozygous for the deletion. One patient is from Tabasco state, in southeastern Mexico, a malaria-endemic zone. The other patient is from Mexico City, which is not a malaria-endemic area. Their families have no non-Mexican ancestors and their previous generations were born in Mexico. Both patients carry the HLA-B*3501 subtype, characteristic of Amerindians and Asian populations. Familial and HLA data led us to conclude that these two patients are the first report of SLC4A1delta27 in Amerindians. The nucleotide analysis showing a perfect match sequence between Southeast Asian and Mexican patients suggests, but does not prove, that the Mexican gene is not a de novo mutation. Instead, this gene might be the result of migration of individuals with Asian ancestry into the Mexican gene pool. We are looking for other families with the mutation to detect, by HLA analysis, the ancient ethnic origin of these patients. 相似文献
69.
In an attempt to improve the detection of peroxisome proliferation as a biomarker in environmental pollution assessment, we have applied a novel approach based on peroxisomal proteomics. Peroxisomal proteins from digestive glands of mussels Mytilus galloprovincialis were analyzed using 2-DE and MS. We have generated a reference 2-DE map from samples obtained in a well-studied reference area and compared this with peroxisomal proteomes from other sequenced genomes. In addition, by comparing 2-DE maps from control samples with samples obtained in a polluted area, we have characterized the peroxisome proliferation expression pattern associated with exposure to a polluted environment. Over 100 spots were reproducibly resolved per 2-DE map; 55 differentially expressed spots were quantitatively detected and analyzed, and 14 of these showed an increase in protein expression of more than fourfold. Epoxide hydrolase, peroxisomal antioxidant enzyme, and sarcosine oxidase (SOX) have been identified by ESI MS/MS, and acyl-CoA oxidase, multifunctional protein, and Cu,Zn-superoxide dismutase were immunolocalized by Western blotting. Our results indicate that a peroxisomal protein pattern associated to marine pollutant exposure can be generated, and this approach may have a greater potential as biomarker than traditional, single-protein markers. 相似文献
70.
Cold hardiness of Habrobracon hebetor (Say) (Hymenoptera: Braconidae), a parasitoid of pyralid moths
Carrillo MA Heimpel GE Moon RD Cannon CA Hutchison WD 《Journal of insect physiology》2005,51(7):759-768
The ectoparasitoid Habrobracon hebetor (Say) attacks stored-product infesting pyralid moths that are able to overwinter under extremely cold conditions. The extent to which H. hebetor can withstand these conditions is not known, but has important implications for the ability of H. hebetor to provide long-term suppression of these pests in temperate climates. We investigated basic cold hardiness aspects of a mutant eye-color strain of H. hebetor. Feeding larvae and adults of H. hebetor had supercooling points (SCPs) at temperatures higher than those of eggs and pupae. Mean SCPs of females and males were equivalent, as were those of naked and silk-encased pupae. Feeding on honey prior to being subjected to low temperatures significantly increased the SCP of adult females by approximately 8 degrees C. Mortality of pupae and adults increased significantly whenever the temperature dropped below the mean SCP, indicating that H. hebetor does not tolerate freezing. For pupae and adults exposed to -12 and -5 degrees C, the hourly mortality rate increased with time of exposure. Pupae and adults exposed to -12 degrees C for different time intervals showed high mortality after only 1d of exposure. At -5 degrees C, none survived 12d of exposure. A better understanding of how well this parasitoid tolerates low temperatures will be useful in evaluating its potential as a biological control agent of stored-product moths in temperate regions. 相似文献