237 research outputs found
A mathematical model and CD4+ lymphocyte dynamics in HIV infection.
The paper presents a model of CD4 + lymphocyte dynamics in HIV-infected persons. The model incorporates a feedback mechanism regulating the production of T lymphocytes and simulates the dynamics of CD8 + lymphocytes, whose production is assumed to be closely linked to that of CD4 + cells. Because CD4 + lymphocyte counts are a good prognostic indicator of HIV infection, the model was used to simulate such therapeutic interventions as chemotherapy and active and passive immunization. The model also simulated the therapeutic administration of anti-CD8 antibodies; this intervention was assumed to activate T-cell production by activating a feedback mechanism blocked by the high numbers of CD8 + lymphocytes present in HIV-infected persons. The character and implications of the model are discussed in the context of other mathematical models used in HIV infection
Criminal Victimisation and Depression in the Czech Republic
Since the fall of communism in 1989, criminal victimization has become an issue in the Czech Republic, & research indicates that it is a stressful experience. The relationship between criminal victimization & depression was examined by adding fear of crime, protection against crime, avoidance of crime, mastery over one's life, social support, & trust in government (as well as sociodemographic controls) to successive regression equations. A total of 703 Czech households in the second of a three-wave (1994-1996) panel study were studied. For men, the total & direct effects of criminal victimization on depression were significant. However, the relation of men's fear of crime & depression was mediated by avoidance. For women, criminal victimization was not related to depression. The relation of women's fear of crime & depression was mediated by mastery. Interpretations of these results are grounded in the different relevance criminal victimization has for the well-being of men & women
Collectivization and transformation of Czechoslovak and Czech agriculture in the years 1945 - 2004, legal normative view
1 Abstrakt Předmětem této práce je sledování proměn určitého výseku právního řádu, regulujícího organizaci a fungování zemědělství, v období přechodu z jednoho režimu do jiného režimu a v období jejich stabilizace. Práce pojednává o normativní regulaci československého a českého zemědělství v období uplatňování jeho kolektivizované podoby a v druhé části pak v období přechodu československého a českého zemědělství na jeho tržní podobu. Kolektivizace a vlastní vývoj socializovaného československého zemědělství je vymezena léty 1949 až 1990, transformace či spíše dekolektivizace a další vývoj tržního, nejprve československého a poté českého zemědělství, je datován od roku 1990 prakticky dodnes, přičemž tato práce se zabývá vývojem zkoumané právní úpravy jen do roku 2004, tedy do doby vstupu České republiky do Evropské unie. Od roku 2004 právní úprava již přestává být výlučnou záležitostí českého státu a musí být přizpůsobena právu Evropské unie, stejně jako ekonomické podmínky fungování tržního zemědělství jsou modifikovány uplatňováním společné zemědělské politiky Evropské unie. Kolektivizace a dekolektivizace je v této práci pojata z hlediska jejich družstevních forem, přičemž specifická problematika státních statků byla v této práci ponechána vědomě stranou, přestože podíl státních statků na socializaci...1 Abstract The subject of this work is to monitor a certain section changes the rule of law, regulating the organization and functioning of agriculture in the transition from one mode to another mode and period of stabilization. The work deals with the normative regulation of the Czechoslovak and Czech agriculture in the period of collectivized application form and the second part of the transition period in Czechoslovak and Czech agriculture on the market form. Collectivization and the actual development of the Czechoslovak socialized agriculture is defined as the years 1949-1990, transformation, or rather de- collectivization and the further development of the market, first Czechoslovak and later Czech agriculture, is dated from 1990 almost until today, and this work deals with the investigation of the legislation referred to by 2004, until the accession of the Czech Republic into the European Union. Since 2004 legislation has already ceased to be exclusively a matter of the state and must be adapted to European Union law, as well as the functioning of the market economic conditions of agriculture are modified implementation of the Common Agricultural Policy of the European Union. Collectivization and de-collectivization in this work is conceived in terms of cooperative forms, the specific issue of state...Department of Legal HistoryKatedra právních dějinFaculty of LawPrávnická fakult
Economic Change and Change in Well-Being in the Czech Republic, with Comparisons to Married Women in the United States
Examines the effects of economic change on individual well-being for a panel of married Czech women compared with a US sample from IA (N = 192 & 386, respectively, in 1990/91). Questionnaire data show that respondents who were forced to make economic adjustments reducing their standard of living also reported increased health problems & depressive symptoms. Contrary to some US findings the relationship between economic adjustments & change in depressive symptoms was strongest among those who reported having the strongest sense of personal control (mastery) & the highest perceived social support. Compared with the US sample, married Czech women reported more depressive symptoms, had more health problems, & were lower in feelings of mastery. In addition, Czech women recorded significantly stronger paths linking education to changes in health conditions & depressive symptoms, whereas US women had significantly stronger paths linking actual economic conditions to subsequent economic adjustments. Data suggest that the US stress-distress model applies in the Czech Republic as well, but further understanding of the differentiated role of social support & mastery for Czech & US women is necessray to more completely interpret the observed interactions
Household item ownership and self-rated health: material and psychosocial explanations
BACKGROUND: There has been an ongoing debate whether the effects of socioeconomic factors on health are due to absolute poverty and material factors or to relative deprivation and psychosocial factors. In the present analyses, we examined the importance for health of material factors, which may have a direct effect on health, and of those that may affect health indirectly, through psychosocial mechanisms. METHODS: Random national samples of men and women in Hungary (n = 973) and Poland (n = 1141) were interviewed (response rates 58% and 59%, respectively). The subjects reported their self-rated health, socioeconomic circumstances, including ownership of different household items, and perceived control over life. Household items were categorised as "basic needs", "socially oriented", and "luxury". We examined the association between the ownership of different groups of items and self-rated health. Since the lists of household items were different in Hungary and Poland, we conducted parallel identical analyses of the Hungarian and Polish data. RESULTS: The overall prevalence of poor or very poor health was 13% in Poland and 25% in Hungary. Education, material deprivation and the number of household items were all associated with poor health in bivariate analyses. All three groups of household items were positively related to self-rated health in age-adjusted analyses. The relation of basic needs items to poor health disappeared after controlling for other socioeconomic variables (mainly material deprivation). The relation of socially oriented and luxury items to poor health, however, persisted in multivariate models. The results were similar in both datasets. CONCLUSIONS: These data suggest that health is influenced by both material and psychosocial aspects of socioeconomic factors
Lipocalin-2 Deficiency Attenuates Insulin Resistance Associated With Aging and Obesity
OBJECTIVE - The proinflammatory cytokines/adipokines produced from adipose tissue act in an autocrine and/or endocrine manner to perpetuate local inflammation and to induce peripheral insulin resistance. The present study investigates whether lipocalin-2 deficiency or replenishment with this adipokine has any impact on systemic insulin sensitivity and the underlying mechanisms. METHODS AND RESULTS - Under conditions of aging or dietary-/genetic-induced obesity, lipocalin-2 knockout (Lcn2-KO) mice show significantly decreased fasting glucose and insulin levels and improved insulin sensitivity compared with their wild-type littermates. Despite enlarged fat mass, inflammation and the accumulation of lipid peroxidation products are significantly attenuated in the adipose tissues of Lcn2-KO mice. Adipose fatty acid composition of these mice varies significantly from that in wild-type animals. The amounts of arachidonic acid (C20:4 n6) are elevated by aging and obesity and are paradoxically further increased in adipose tissue, but not skeletal muscle and liver of Lcn2-KO mice. On the other hand, the expression and activity of 12-lipoxygenase, an enzyme responsible for metabolizing arachidonic acid, and the production of tumor necrosis factor-α (TNF-α), a critical insulin resistance-inducing factor, are largely inhibited by lipocalin-2 deficiency. Lipocalin-2 stimulates the expression and activity of 12-lipoxygenase and TNF-α production in fat tissues. Cinnamyl-3,4- dihydroxy-α-cyanocinnamate (CDC), an arachidonate lipoxygenase inhibitor, prevents TNF-α expression induced by lipocalin-2. Moreover, treatment with TNF-α neutralization antibody or CDC significantly attenuated the differences of insulin sensitivity between wild-type and Lcn2-KO mice. CONCLUSIONS - Lipocalin-2 deficiency protects mice from developing aging- and obesity-induced insulin resistance largely by modulating 12-lipoxygenase and TNF-α levels in adipose tissue. © 2010 by the American Diabetes Association.link_to_OA_fulltex
Astrocytes grown in Alvetex® 3 dimensional scaffolds retain a non-reactive phenotype
yesProtocols which permit the extraction of primary astrocytes from either embryonic or postnatal mice are well established however astrocytes in culture are different to those in the mature CNS. Three dimensional (3D) cultures, using a variety of scaffolds may enable better phenotypic properties to be developed in culture. We present data from embryonic (E15) and postnatal (P4) murine primary cortical astrocytes grown on coated coverslips or a 3D polystyrene scaffold, Alvetex. Growth of both embryonic and postnatal primary astrocytes in the 3D scaffold changed astrocyte morphology to a mature, protoplasmic phenotype. Embryonic-derived astrocytes in 3D expressed markers of mature astrocytes, namely the glutamate transporter GLT-1 with low levels of the chondroitin sulphate proteoglycans, NG2 and SMC3. Embroynic astrocytes derived in 3D show lower levels of markers of reactive astrocytes, namely GFAP and mRNA levels of LCN2, PTX3, Serpina3n and Cx43. Postnatal-derived astrocytes show few protein changes between 2D and 3D conditions. Our data shows that Alvetex is a suitable scaffold for growth of astrocytes, and with appropriate choice of cells allows the maintenance of astrocytes with the properties of mature cells and a non-reactive phenotype.BBSR
Early diagnosis of pancreatic cancer: neutrophil gelatinase-associated lipocalin as a marker of pancreatic intraepithelial neoplasia
Pancreatic cancer is a highly lethal malignancy with a dismal 5-year survival of less than 5%. The scarcity of early biomarkers has considerably hindered our ability to launch preventive measures for this malignancy in a timely manner. Neutrophil gelatinase-associated lipocalin (NGAL), a 24-kDa glycoprotein, was reported to be upregulated nearly 27-fold in pancreatic cancer cells compared to normal ductal cells in a microarray analysis. Given the need for biomarkers in the early diagnosis of pancreatic cancer, we investigated the expression of NGAL in tissues with the objective of examining if NGAL immunostaining could be used to identify foci of pancreatic intraepithelial neoplasia, premalignant lesions preceding invasive cancer. To examine a possible correlation between NGAL expression and the degree of differentiation, we also analysed NGAL levels in pancreatic cancer cell lines with varying grades of differentiation. Although NGAL expression was strongly upregulated in pancreatic cancer, and moderately in pancreatitis, only a weak expression could be detected in the healthy pancreas. The average composite score for adenocarcinoma (4.26±2.44) was significantly higher than that for the normal pancreas (1.0) or pancreatitis (1.0) (P<0.0001). Further, although both well- and moderately differentiated pancreatic cancer were positive for NGAL, poorly differentiated adenocarcinoma was uniformly negative. Importantly, NGAL expression was detected as early as the PanIN-1 stage, suggesting that it could be a marker of the earliest premalignant changes in the pancreas. Further, we examined NGAL levels in serum samples. Serum NGAL levels were above the cutoff for healthy individuals in 94% of pancreatic cancer and 62.5% each of acute and chronic pancreatitis samples. However, the difference between NGAL levels in pancreatitis and pancreatic cancer was not significant. A ROC curve analysis revealed that ELISA for NGAL is fairly accurate in distinguishing pancreatic cancer from non-cancer cases (area under curve=0.75). In conclusion, NGAL is highly expressed in early dysplastic lesions in the pancreas, suggesting a possible role as an early diagnostic marker for pancreatic cancer. Further, serum NGAL measurement could be investigated as a possible biomarker in pancreatitis and pancreatic adenocarcinoma
Determinants of self-rated health in women: a population-based study in Armavir Marz, Armenia, 2001 & 2004
<p>Abstract</p> <p>Background</p> <p>The former soviet Republic of Armenia entered a turbulent and long-lasting economic transition when it declared its independence in 1991. This analysis sought to identify the determinants of poor self-rated health as an indirect measure of health status and mortality prognosis in an adult female population during a period of socio-economic transition in Armenia.</p> <p>Methods</p> <p>Differences in self-rated health in women respondents were analyzed along three main dimensions: social, behavioral/attitudinal, and psychological. The data used were generated from cross-sectional household health surveys conducted in Armavir <it>marz </it>in 2001 and 2004. The surveys utilized the same instruments and study design (probability proportional to size, multistage cluster sampling with a combination of interviewer-administered and self-administered surveys) and generated two independent samples of households representative of Armavir <it>marz</it>. Binary logistic regression models with self-rated health as the outcome were fitted to the 2001 and 2004 datasets and a combined 2001/2004 dataset.</p> <p>Results</p> <p>Overall, 2 038 women aged 18 and over participated in the two surveys (1 019 in each). The rate of perceived "poor" health was relatively high in both surveys: 38.1% in 2001 and 27.0% in 2004. The sets of independent predictors of poor self-rated health were similar in all three models and included severe and moderate material deprivation, probable and possible depression, low level of education, and having ever smoked. These predictors mediated the effect of women's economic activity (including unemployment), ethnicity, low access to/utilization of healthcare services, and living alone on self-rated health.</p> <p>Conclusion</p> <p>Material deprivation was the most influential predictor of self-rated health. Thus, social reforms to decrease the gap between the rich and poor are recommended as a powerful tool for reducing health inequalities and improving the health status of the population.</p
Advanced Technology Large-Aperture Space Telescope (ATLAST): A Technology Roadmap for the Next Decade
The Advanced Technology Large-Aperture Space Telescope (ATLAST) is a set of
mission concepts for the next generation of UVOIR space observatory with a
primary aperture diameter in the 8-m to 16-m range that will allow us to
perform some of the most challenging observations to answer some of our most
compelling questions, including "Is there life elsewhere in the Galaxy?" We
have identified two different telescope architectures, but with similar optical
designs, that span the range in viable technologies. The architectures are a
telescope with a monolithic primary mirror and two variations of a telescope
with a large segmented primary mirror. This approach provides us with several
pathways to realizing the mission, which will be narrowed to one as our
technology development progresses. The concepts invoke heritage from HST and
JWST design, but also take significant departures from these designs to
minimize complexity, mass, or both.
Our report provides details on the mission concepts, shows the extraordinary
scientific progress they would enable, and describes the most important
technology development items. These are the mirrors, the detectors, and the
high-contrast imaging technologies, whether internal to the observatory, or
using an external occulter. Experience with JWST has shown that determined
competitors, motivated by the development contracts and flight opportunities of
the new observatory, are capable of achieving huge advances in technical and
operational performance while keeping construction costs on the same scale as
prior great observatories.Comment: 22 pages, RFI submitted to Astro2010 Decadal Committe
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