897 resultados para Human rhythmic activities
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This research is aimed at developing an instrument for measuring human resource quality in organizations. The researcher has developed the instrument for measuring HRQ based on extensive literature survey and expert opinion. Statistical validity of the Instrument has also been established. This instrument was used to measure the changes in Human Resource Quality in selected organizations wherein quality management practices are being implemented. Data collected was analyzed and presented in this thesis. It has been found that there are significant changes in all the indicators of Human Resource Quality. There is improvement in Cultural Change Index(CCI), Quality of Work Life Index(QWLI) and Employee Satisfaction Index(ESI). The Human Resource Quality index has also increased significantly in all the organizations. It has been observed from the study that implementation of TQM leads to significant changes in Human Resource Quality. This instrument is capable of measuring minor variations in each indicator of HRQ and can be used to identify areas of weakness and strength in the case of Human Resource Quality. The instrument can further be modified by future research. This research work provided excellent opportunities for the researcher for self-development and has made him confident to undertake such activities for the benefit of the learning community.
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In the present study we address the issue on gut associated lactic acid bacteria (LAB) isolated from the intestine of estuarine fish Mugil cephalus using de Man Rogossa and Sharpe (MRS) agar. LAB isolates were identified biochemically and screened for their ability to inhibit in vitro growth of various fish, shrimp and human pathogens. Most of the LAB isolates displayed an improved antagonism against fish pathogens compared to shrimp and human pathogens. Selected representative strains displaying high antibacterial activity were identified using 16S rRNA gene sequence analysis. Of the selected strains Lactobacillus brevis was the most predominant. Four other species of Lactobacillus, Enterobacter hormaechei and Enterobacter ludwigii were also identified. It was also observed that even among same species, considerable diversity with respect to substrate utilization persisted. Considering the euryhaline nature of grey mullet (Mugil cephalus), the LAB isolated from the gut possessed good tolerance to varying salt concentrations. This finding merits further investigation to evaluate whether the isolated LAB could be used as probiotics in various fresh and sea water aquaculture
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There is increasing interest in how humans influence spatial patterns in biodiversity. One of the most frequently noted and marked of these patterns is the increase in species richness with area, the species–area relationship (SAR). SARs are used for a number of conservation purposes, including predicting extinction rates, setting conservation targets, and identifying biodiversity hotspots. Such applications can be improved by a detailed understanding of the factors promoting spatial variation in the slope of SARs, which is currently the subject of a vigorous debate. Moreover, very few studies have considered the anthropogenic influences on the slopes of SARs; this is particularly surprising given that in much of the world areas with high human population density are typically those with a high number of species, which generates conservation conflicts. Here we determine correlates of spatial variation in the slopes of species–area relationships, using the British avifauna as a case study. Whilst we focus on human population density, a widely used index of human activities, we also take into account (1) the rate of increase in habitat heterogeneity with increasing area, which is frequently proposed to drive SARs, (2) environmental energy availability, which may influence SARs by affecting species occupancy patterns, and (3) species richness. We consider environmental variables measured at both local (10 km × 10 km) and regional (290 km × 290 km) spatial grains, but find that the former consistently provides a better fit to the data. In our case study, the effect of species richness on the slope SARs appears to be scale dependent, being negative at local scales but positive at regional scales. In univariate tests, the slope of the SAR correlates negatively with human population density and environmental energy availability, and positively with the rate of increase in habitat heterogeneity. We conducted two sets of multiple regression analyses, with and without species richness as a predictor. When species richness is included it exerts a dominant effect, but when it is excluded temperature has the dominant effect on the slope of the SAR, and the effects of other predictors are marginal.
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The nicotinic Acetylcholine Receptor (nAChR) is the major class of neurotransmitter receptors that is involved in many neurodegenerative conditions such as schizophrenia, Alzheimer's and Parkinson's diseases. The N-terminal region or Ligand Binding Domain (LBD) of nAChR is located at pre- and post-synaptic nervous system, which mediates synaptic transmission. nAChR acts as the drug target for agonist and competitive antagonist molecules that modulate signal transmission at the nerve terminals. Based on Acetylcholine Binding Protein (AChBP) from Lymnea stagnalis as the structural template, the homology modeling approach was carried out to build three dimensional model of the N-terminal region of human alpha(7)nAChR. This theoretical model is an assembly of five alpha(7) subunits with 5 fold axis symmetry, constituting a channel, with the binding picket present at the interface region of the subunits. alpha-netlrotoxin is a potent nAChR competitive antagonist that readily blocks the channel resulting in paralysis. The molecular interaction of alpha-Bungarotoxin, a long chain alpha-neurotoxin from (Bungarus multicinctus) and human alpha(7)nAChR seas studied. Agonists such as acetylcholine, nicotine, which are used in it diverse array of biological activities, such as enhancements of cognitive performances, were also docked with the theoretical model of human alpha(7)nAChR. These docked complexes were analyzed further for identifying the crucial residues involved in interaction. These results provide the details of interaction of agonists and competitive antagonists with three dimensional model of the N-terminal region of human alpha(7)nAChR and thereby point to the design of novel lead compounds.
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Glucosinolates (GLSs) are found in Brassica vegetables. Examples of these sources include cabbage, Brussels sprouts, broccoli, cauliflower and various root vegetables (e.g. radish and turnip). A number of epidemiological studies have identified an inverse association between consumption of these vegetables and the risk of colon and rectal cancer. Animal studies have shown changes in enzyme activities and DNA damage resulting from consumption of Brassica vegetables or isothiocyanates, the breakdown products (BDP) of GLSs in the body. Mechanistic studies have begun to identify the ways in which the compounds may exert their protective action but the relevance of these studies to protective effects in the human alimentary tract is as yet unproven. In vitro studies with a number of specific isothiocyanates have suggested mechanisms that might be the basis of their chemoprotective effects. The concentration and composition of the GLSs in different plants, but also within a plant (e.g. in the seeds, roots or leaves), can vary greatly and also changes during plant development. Furthermore, the effects of various factors in the supply chain of Brassica vegetables including breeding, cultivation, storage and processing on intake and bioavailability of GLSs are extensively discussed in this paper.
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There is increasing awareness that the human gut microflora plays a critical role in maintaining host health, both within the gastrointestinal tract and, through the absorption of metabolites, systemically. An 'optimal' gut microflora establishes an efficient barrier to the invasion and colonisation of the gut by pathogenic bacteria, produces a range of metabolic substrates which in turn are utilized by the host (e.g. vitamins and short chain fatty acids) and stimulates the immune system in a non-inflammatory manner. Although little is known about the individual species of bacteria responsible for these beneficial activities, it is generally accepted that the bifidobacteria and lactobacilli constitute important components of the beneficial gut microflora. A number of diet-based microflora management tools have been developed and refined over recent decades including probiotic, prebiotic and synbiotic approaches. Each aims to stimulate numbers and/or activities of the bifidobacteria and lactobacilli within the gut microflora. The aim of this article is to examine how prebiotics are being applied to the improvement of human health and to review the scientific evidence supporting their use.
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Synbiotics are recognized means of modulating gut microbiota composition and activities. However, whether synbiotics are superior to prebiotics and probiotics alone in moderating the gut microbiota towards a purportedly healthy composition has not been determined. Eight selected synbiotics (short-chain fructooligosaccharides or fructooligosaccharides, each combined with one of four probiotics, Lactobacillus fermentum ME-3, Lactobacillus plantarum WCFS1, Lactobacillus paracasei 8700:2 or Bifidobacterium longum 46) were added to 24-h pH-controlled anaerobic faecal batch cultures. The prebiotic and probiotic components were also tested alone to determine their respective role within the synbiotic for modulation of the faecal microbiota. Effects upon major groups of the microbiota were evaluated using FISH. Rifampicin variant probiotic strains were used to assess probiotic levels. Synbiotic and prebiotics increased bifidobacteria and the Eubacterium rectale-Clostridium coccoides group. Lower levels of Escherichia coli were retrieved with these combinations after 5 and 10 h of fermentation. Probiotics alone had little effect upon the groups, however. Multivariate analysis revealed that the effect of synbiotics differed from the prebiotics as higher levels of Lactobacillus-Enterococcus were observed when the probiotic was stimulated by the prebiotic component. Here, the synbiotic approach was more effective than prebiotic or probiotic alone to modulate the gut microbiota.
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Gut bacteria can be categorised as being either beneficial or potentially pathogenic due to their metabolic activities and fermentation end-products. Health-promoting effects of the microflora may include immunostimulation, improved digestion and absorption, vitamin synthesis, inhibition of the growth of potential pathogens and lowering of gas distension. Detrimental effects are carcinogen production, intestinal putrefaction, toxin production, diarrhoea/constipation and intestinal infections. Certain indigenous bacteria such as bifidobacteria and lactobacilli are considered to be examples of health-promoting constituents of the microflora. They may aid digestion of lactose in lactose-intolerant individuals, reduce diarrhoea, help resist infections and assist in inflammatory conditions. Probiotics, prebiotics and synbiotics are functional foods that fortify the lactate producing microflora of the human or animal gut.
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Insulin is a prebiotic food ingredient, which suppresses colon tumour growth and development in rats. In the gut lumen, it is fermented to lactic acid and short chain fatty acids (SCFA). Of these, butyrate has suppressing agent activities, but little is known concerning cellular responses to complex fermentation samples. To investigate the effects of fermentation products of insulin on cellular responses related to colon carcinogenesis. Fermentations were performed in anaerobic batch cultures or in a three-stage fermentation model that simulates conditions in colon-segments (proximal, transverse, distal). Substrate was insulin enriched with oligofructose (Raftilose® Synergy1), fermented with probiotics (Bifidobacterium lactis Bb12, Lactobacillus rhamnosus GG), and/or faecal inocula. HT29 or CaCo-2 cells were incubated with supernatants of the fermented samples (2.5%-25% v/v, 24-72 hours). Cellular parameters of survival, differentiation, tumour progression, and invasive growth were determined. Fermentation supernatants derived from probiotics and Synergy1 were more effective than with glucose. The additional fermentation with faecal slurries produced supernatants with lower toxicity, higher SCFA contents, and distinct cellular functions. The supernatant derived from the gut model vessel representing the distal colon, was most effective for all parameters, probably on account of higher butyrate-concentrations. Biological effects of insulin upon colon cells may be mediated not only by growth stimulation of the lactic acid-producing bacteria and/or production of butyrate, but also by other bacteria and products of the gut lumen. These newly reported properties of the supernatants to inhibit growth and metastases in colon tumour cells are important mechanisms of tumour suppression.
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Epidemiological studies indicate that consumption of cruciferous vegetables (CV) can reduce the risk of cancer. Supposed mechanisms are partly the inhibition of phase I and the induction of phase II enzymes. The aim of this study was to investigate in vitro and in vivo effects of watercress (WC), a member of the CV family, on chemopreventive parameters using human peripheral blood mononuclear cells (PBMC) as surrogate cells. We investigated the hypothesis that WC reduces cancer risk by inducing detoxification enzymes in a genotype-dependent manner. In vitro gene expression and enzyme activity experiments used PBMC incubated with a crude extract from fresh watercress (WCE, 0.1-10 mu L/mL with 8.2 g WC per 1 mL extract) or with one main key compound phenethyl isothiocyanate (PEITC, 1-10 mu M). From an in vivo perspective, gene expression and glutathione S-transferase (GST) polymorphisms were determined in PBMC obtained from a human intervention study in which subjects consumed 85 g WC per day for 8 weeks. The influence of WC consumption on gene expression was determined for detoxification enzymes such as superoxide dismutase 2 (SOD2) and glutathione peroxidase 1 (GPX1), whilst the SOD and GPX activities in red blood cells were also analysed with respect to GST genotypes. In vitro exposure of PBMC to WCE or PEITC (24 h) increased gene expression for both detoxification enzymes GPX1 (5.5-fold, 1 mu L/mL WCE, 3.7-fold 1 mu M PEITC) and SOD2 (12.1-fold, 10 mu L/mL WCE, 7.3-fold, 10 mu M PEITC), and increased SOD2 activity (1.9-fold, 10 mu L/mL WCE). The WC intervention had no significant effect on in vivo PBMC gene expression, as high individual variations were observed. However, a small but significant increase in GPX (p = 0.025) and SOD enzyme activity (p = 0.054) in red blood cells was observed in GSTM1*0, but not in GSTM1*1 individuals, whilst the GSTT1 genotype had no impact. The results indicate that WC is able to modulate the enzymes SOD and GPX in blood cells in vitro and in vivo, and suggest that the capacity of moderate intake of CV to induce detoxification is dependent in part on the GSTM1 genotype.
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Background Epidemiological studies suggest that soy consumption contributes to the prevention of coronary heart disease. The proposed anti-atherogenic effects of soy appear to be carried by the soy isoflavones with genistein as the most abundant compound. Aim of the study To identify proteins or pathways by which genistein might exert its protective activities on atherosclerosis, we analyzed the proteomic response of primary human umbilical vein endothelial cells ( HUVEC) that were exposed to the pro-atherosclerotic stressors homocysteine or oxidized low-density lipoprotein (ox-LDL). Methods HUVEC were incubated with physiological concentrations of homocysteine or ox-LDL in the absence and presence of genistein at concentrations that can be reached in human plasma by a diet rich in soy products (2.5 muM) or by pharmacological intervention ( 25 muM). Proteins from HUVEC were separated by two-dimensional polyacrylamide gel electrophoresis and those that showed altered expression level upon genistein treatment were identified by peptide mass fingerprints derived from tryptic digests of the protein spots. Results Several proteins were found to be differentially affected by genistein. The most interesting proteins that were potently decreased by homocysteine treatment were annexin V and lamin A. Annexin V is an antithrombotic molecule and mutations in nuclear lamin A have been found to result in perturbations of plasma lipids associated with hypertension. Genistein at low and high concentrations reversed the stressor-induced decrease of these anti-atherogenic proteins. Ox-LDL treatment of HUVEC resulted in an increase in ubiquitin conjugating enzyme 12, a protein involved in foam cell formation. Treatment with genistein at both doses reversed this effect. Conclusions Proteome analysis allows the identification of potential interactions of dietary components in the molecular process of atherosclerosis and consequently provides a powerful tool to define biomarkers of response.
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Coronary heart disease (CHD) is the leading cause of mortality in Western societies, affecting about one third of the population before their seventieth year. Over the past decades modifiable risk factors of CHD have been identified, including smoking and diet. These factors when altered can have a significant impact on an individuals' risk of developing CHD, their overall health and quality of life. There is strong evidence suggesting that dietary intake of plant foods rich in fibre and polyphenolic compounds, effectively lowers the risk of developing CHD. However, the efficacy of these foods often appears to be greater than the sum of their recognised biologically active parts. Here we discuss the hypothesis that beneficial metabolic and vascular effects of dietary fibre and plant polyphenols are due to an up regulation of the colon-systemic metabolic axis by these compounds. Fibres and many polyphenols are converted into biologically active compounds by the colonic microbiota. This microbiota imparts great metabolic versatility and dynamism, with many of their reductive or hydrolytic activities appearing complementary to oxidative or conjugative human metabolism. Understanding these microbial activities is central to determining the role of different dietary components in preventing or beneficially impacting on the impaired lipid metabolism and vascular dysfunction that typifies CHD and type 11 diabetes. This approach lays the foundation for rational selection of health promoting foods, rational target driven design of functional foods, and provides an essential thus-far, overlooked, dynamic to our understanding of how foods recognised as "healthy" impact on the human metabonome.
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Rat kidney glutamine transaminase K (GTK) exhibits broad specificity both as an aminotransferase and as a cysteine S-conjugate beta-lyase. The beta-lyase reaction products are pyruvate, ammonium and a sulfhydryl-containing fragment. We show here that recombinant human GTK (rhGTK) also exhibits broad specificity both as an aminotransferase and as a cysteine S-conjugate beta-lyase. S-(1,1,2,2-Tetrafluoroethyl)-L-CySteine is an excellent aminotransferase and beta-lyase substrate of rhGTK. Moderate aminotransferase and beta-lyase activities occur with the chemopreventive agent Se-methyl-L-selenocysteine. L-3-(2-Naphthyl)alanine, L-3-(1-naphthyl)alanine, 5-S-L-cysteinyldopamine and 5-S-L-cysteinyl-L-DOPA are measurable aminotransferase substrates, indicating that the active site can accommodate large aromatic amino acids. The alpha-keto acids generated by transamination/L-amino acid oxidase activity of the two catechol cysteine S-conjugates are unstable. A slow rhGTK-catalyzed beta-elimination reaction, as measured by pyruvate formation, was demonstrated with 5-S-L-CysteinyIdopamine, but not with 5-S-L-CySteinyl-L-DOPA. The importance of transamination, oxidation and beta-elimination reactions involving 5-S-L-cysteinyldopamine, 5-S-L-cysteinyt-L-DOPA and Se-methyl-L-selenocysteirte in human tissues and their biological relevance are discussed. (C) 2008 Elsevier Inc. All rights reserved.
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Tea polyphenols, especially the catechins, are potent antimicrobial and antioxidant agents, with positive effects on human health. White tea is one of the less studied teas but the flavour is more accepted than that of green tea in Europe. The concentrations of various catechins in 13 different kinds of infusion were determined by capillary electrophoresis. The total polyphenol content (Folin-Ciocalteu method), the trolox equivalent antioxidant capacity (TEAC value determined with the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation) and the inhibitory effects of infusions on the growth of some microorganisms were determined. Five different infusions (black, white, green and red teas and rooibos infusion) were added to a model food system, comprising a sunflower oil-in-water emulsion containing 0% or 0.2% bovine serum albumin (BSA), and the oxidative stability was studied during storage at 37 degrees C. Oxidation of the oil was monitored by determination of the peroxide value. The highest radical-scavenging activity observed was for the green and white teas. Emulsions containing these extracts from these teas were much more stable during storage when BSA was present than when it was not present, even though BSA itself did not provide an antioxidant effect (at 0.2% concentration). Rooibos infusion did not show the same synergy with BSA. Green tea and white tea showed similar inhibitions of several microorganisms and the magnitude of this was comparable to that of the commercial infusion 2 (C.I.2), "te de la belleza". This tea also had an antioxidant activity comparable to green tea. (C) 2007 Published by Elsevier Ltd.
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Diet, among other environmental and genetic factors, is currently recognised to have an important role in health and disease. There is increasing evidence that the human colonic microbiota can contribute positively towards host nutrition and health. As such, dietary modulation has been proposed as important for improved gut health, especially during the highly sensitive stage of infancy. Differences in gut microflora composition and incidence of infection occur between breast- and formula-fed infants. Human milk components that cannot be duplicated in infant formulae could possibly account for these differences. However, various functional food ingredients such as oligosaccharides, prebiotics, proteins and probiotics could effect a beneficial modification in the composition and activities of gut microflora of infants. The aim of the present review is to describe existing knowledge on the composition and metabolic activities of the gastrointestinal microflora of human infants and discuss various possibilities and opportunities for its nutritional modulation.