998 resultados para small dependence
Resumo:
Swain corrects the chi-square overidentification test (i.e., likelihood ratio test of fit) for structural equation models whethr with or without latent variables. The chi-square statistic is asymptotically correct; however, it does not behave as expected in small samples and/or when the model is complex (cf. Herzog, Boomsma, & Reinecke, 2007). Thus, particularly in situations where the ratio of sample size (n) to the number of parameters estimated (p) is relatively small (i.e., the p to n ratio is large), the chi-square test will tend to overreject correctly specified models. To obtain a closer approximation to the distribution of the chi-square statistic, Swain (1975) developed a correction; this scaling factor, which converges to 1 asymptotically, is multiplied with the chi-square statistic. The correction better approximates the chi-square distribution resulting in more appropriate Type 1 reject error rates (see Herzog & Boomsma, 2009; Herzog, et al., 2007).
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Few data are available on the occurrence of chlamydial infections in wild small mammals. We investigated the significance of free-living small mammals as reservoirs or transmission hosts for microorganisms of the phylum/class Chlamydiae. We obtained 3,664 tissue samples from 911 animals in Switzerland, Germany, Austria, the Czech Republic, and Afghanistan. Samples included internal organs (n = 3,652) and feces (n = 12) from 679 rodents (order Rodentia) and 232 insectivores (order Soricomorpha) and were tested by three TaqMan® real-time PCRs specific for members of the family Chlamydiaceae and selected Chlamydia-like organisms such as Parachlamydia spp. and Waddlia spp. Only one of 911 (0.11%) animals exhibited a questionable positive result by Chlamydiaceae-specific real-time PCR. Five of 911 animals were positive by specific real-time PCR for Parachlamydia spp. but could not be confirmed by quantitative PCR targeting the Parachlamydia acanthamoebae secY gene (secY qPCR). One of 746 animals (0.13%) was positive by real-time PCR for Waddlia chondrophila. This result was confirmed by Waddlia secY qPCR. This is the first detection of Chlamydia-like organisms in small wildlife in Switzerland. Considering previous negative results for Chlamydiaceae in wild ruminant species from Switzerland, these data suggest that wild small mammals are unlikely to be important carriers or transport hosts for Chamydiaceae and Chlamydia-like organisms.
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Hirsutism, acne, alopecia, and oligo-amenorrhea are clinical expressions of hyperandrogenism, one of the most frequent endocrine disorders in women of reproductive age. Women referred to our endocrine clinics for skin symptoms of hyperandrogenism underwent a laboratory workup to evaluate hormone measurements and received antiandrogen therapy. We retrospectively analyzed the outcome of 228 consecutive patients investigated over 6 years.Patients with hirsutism had higher levels of androstenedione, dehydroepiandrosterone sulfate (DHEAS), and salivary testosterone; lower levels of sex hormone-binding globulin (SHBG); and a higher prevalence of oligo-amenorrhea than patients with alopecia, while patients with acne showed intermediate values. Hirsutism score correlated positively with androstenedione, DHEAS, and salivary testosterone, and correlated negatively with SHBG; salivary testosterone showed the highest correlation coefficient. Total testosterone was not significantly different among patients with hirsutism, alopecia, or acne, and did not significantly correlate with hirsutism score. Hirsutism and oligo-amenorrhea were the most sensitive symptoms of hyperandrogenism, and no androgenic parameter alone allowed us to identify all cases of hyperandrogenism.Patients of central European origin sought consultation with milder hirsutism scores than patients of southern European origin. There was, however, no difference in the clinical-biological correlation between these groups, arguing against differences in skin sensitivity to androgens.Polycystic ovary syndrome, defined as hyperandrogenism (hirsutism or elevated androgens) and oligo-amenorrhea, was diagnosed in 63 patients (27.6%), an underestimate compared with other reports that include systematic ovarian ultrasound studies. Neither pelvic ultrasound, used in a limited number of cases, nor the luteinizing hormone/follicle-stimulating hormone ratio helped to distinguish patients with polycystic ovary syndrome from the other diagnostic groups. These included hyperandrogenism (hirsutism or elevated androgens) and eumenorrhea (101 patients; 44.3%); normal androgens (acne or alopecia and eumenorrhea) (51 patients; 22.4%); isolated low SHBG (7 patients; 3.1%); nonclassical congenital adrenal hyperplasia (4 patients; 1.8% of total, 4.9% of patients undergoing cosyntropin stimulation tests); and ovarian tumor (2 patients; 0.9%).Ethinylestradiol and high-dose cyproterone acetate treatment lowered the hirsutism score to 53.5% of baseline at 1 year, and was also effective in treating acne and alopecia. The clinical benefit is ascribed to the peripheral antiandrogenic effect of cyproterone acetate as well as the hormone-suppressive effect of this combination. Salivary testosterone showed the most marked proportional decrease of all the androgens under treatment. Cost-effectiveness and tolerance of ethinylestradiol and high-dose cyproterone acetate compared well with other antiandrogenic drug therapies for hirsutism. The less potent therapy with spironolactone only, a peripheral antiandrogen without hormone-suppressive effect, was effective in treating isolated alopecia in patients with normal androgens.
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It is well known that exposure to low doses of lead causes long-lasting neurobehavioural deficits, but the cellular changes underlying these behavioural changes remain to be elucidated. A protective role of glial cells on neurons through lead sequestration by astrocytes has been proposed. The possible modulation of lead neurotoxicity by neuron-glia interactions was examined in three-dimensional cultures of foetal rat telencephalon. Mixed-brain cell cultures or cultures enriched in either neurons or glial cells were treated for 10 days with lead acetate (10(-6) m), a concentration below the limit of cytotoxicity. Intracellular lead content and cell type-specific enzyme activities were determined. It was found that in enriched cultures neurons stored more lead than glial cells, and each cell type alone stored more lead than in co-culture. Moreover, glial cells but not neurons were more affected by lead in enriched culture than in co-culture. These results show that neuron-glia interactions attenuate the cellular lead uptake and the glial susceptibility to lead, but they do not support the idea of a protective role of astrocytes.
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Recent population genetic studies suggest that staphylococcal cassette chromosome mec (SCCmec) was acquired much more frequently than previously thought. In the present study, we aimed to investigate the diversity of SCCmec elements in a local methicillin-resistant Staphylococcus aureus (MRSA) population. Each MRSA isolate (one per patient) recovered in the Vaud canton of Switzerland from January 2005 to December 2008 was analyzed by the double-locus sequence typing (DLST) method and SCCmec typing. DLST analysis indicated that 1,884/2,036 isolates (92.5%) belong to four predominant clones. As expected from the local spread of a clone, most isolates within clones harbored an identical SCCmec type. However, three to seven SCCmec types have been recovered in every predominant DLST clone, suggesting that some of these elements might have been acquired locally. This pattern could also be explained by distinct importations of related isolates into the study region. The addition of a third highly variable locus to further increase the discriminatory power of typing as well as epidemiological data suggested that most ambiguous situations were explained by the second hypothesis. In conclusion, our study showed that even if the acquisition of new SCCmec elements at a local level likely occurs, it does not explain all the diversity observed in the study region.
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1. As trees in a given cohort progress through ontogeny, many individuals die. This risk of mortality is unevenly distributed across species because of many processes such as habitat filtering, interspecific competition and negative density dependence. Here, we predict and test the patterns that such ecological processes should inscribe on both species and phylogenetic diversity as plants recruit from saplings to the canopy. 2. We compared species and phylogenetic diversity of sapling and tree communities at two sites in French Guiana. We surveyed 2084 adult trees in four 1-ha tree plots and 943 saplings in sixteen 16-m2 subplots nested within the tree plots. Species diversity was measured using Fisher's alpha (species richness) and Simpson's index (species evenness). Phylogenetic diversity was measured using Faith's phylogenetic diversity (phylogenetic richness) and Rao's quadratic entropy index (phylogenetic evenness). The phylogenetic diversity indices were inferred using four phylogenetic hypotheses: two based on rbcLa plastid DNA sequences obtained from the inventoried individuals with different branch lengths, a global phylogeny available from the Angiosperm Phylogeny Group, and a combination of both. 3. Taxonomic identification of the saplings was performed by combining morphological and DNA barcoding techniques using three plant DNA barcodes (psbA-trnH, rpoC1 and rbcLa). DNA barcoding enabled us to increase species assignment and to assign unidentified saplings to molecular operational taxonomic units. 4. Species richness was similar between saplings and trees, but in about half of our comparisons, species evenness was higher in trees than in saplings. This suggests that negative density dependence plays an important role during the sapling-to-tree transition. 5. Phylogenetic richness increased between saplings and trees in about half of the comparisons. Phylogenetic evenness increased significantly between saplings and trees in a few cases (4 out of 16) and only with the most resolved phylogeny. These results suggest that negative density dependence operates largely independently of the phylogenetic structure of communities. 6. Synthesis. By contrasting species richness and evenness across size classes, we suggest that negative density dependence drives shifts in composition during the sapling-to-tree transition. In addition, we found little evidence for a change in phylogenetic diversity across age classes, suggesting that the observed patterns are not phylogenetically constrained.
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Acid-sensing ion channels (ASICs) are neuronal Na(+)-selective channels that are transiently activated by extracellular acidification. ASICs are involved in fear and anxiety, learning, neurodegeneration after ischemic stroke, and pain sensation. The small molecule 2-guanidine-4-methylquinazoline (GMQ) was recently shown to open ASIC3 at physiological pH. We have investigated the mechanisms underlying this effect and the possibility that GMQ may alter the function of other ASICs besides ASIC3. GMQ shifts the pH dependence of activation to more acidic pH in ASIC1a and ASIC1b, whereas in ASIC3 this shift goes in the opposite direction and is accompanied by a decrease in its steepness. GMQ also induces an acidic shift of the pH dependence of inactivation of ASIC1a, -1b, -2a, and -3. As a consequence, the activation and inactivation curves of ASIC3 but not other ASICs overlap in the presence of GMQ at pH 7.4, thereby creating a window current. At concentrations >1 mm, GMQ decreases maximal peak currents by reducing the unitary current amplitude. Mutation of residue Glu-79 in the palm domain of ASIC3, previously shown to be critical for channel opening by GMQ, disrupted the GMQ effects on inactivation but not activation. This suggests that this residue is involved in the consequences of GMQ binding rather than in the binding interaction itself. This study describes the mechanisms underlying the effects of a novel class of ligands that modulate the function of all ASICs as well as activate ASIC3 at physiological pH.
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We show that a simple mixing idea allows one to establish a number of explicit formulas for ruin probabilities and related quantities in collective risk models with dependence among claim sizes and among claim inter-occurrence times. Examples include compound Poisson risk models with completely monotone marginal claim size distributions that are dependent according to Archimedean survival copulas as well as renewal risk models with dependent inter-occurrence times.
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This exploratory, descriptive, cross-sectional, and quantitative study aimed to develop and validate an index of family vulnerability to disability and dependence (FVI-DD). This study was adapted from the Family Development Index, with the addition of social and health indicators of disability and dependence. The instrument was applied to 248 families in the city of Sao Paulo, followed by exploratory factor analysis. Factor validation was performed using the concurrent and discriminant validity of the Lawton scale and Katz Index. The descriptive level adopted for the study was p < 0.05. The final vulnerability index comprised 50 questions classified into seven factors contemplating social and health dimensions, and this index exhibited good internal consistency (Cronbach’s alpha = 0.82). FVI-DD was validated using both the Lawton scale and Katz Index. We conclude that FVI-DD can accurately and reliably assess family vulnerability to disability and dependence.
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PURPOSE: A multicenter, phase II trial investigated the efficacy and toxicity of neoadjuvant docetaxel-cisplatin in locally advanced non-small-cell lung cancer (NSCLC) and examined prognostic factors for patients not benefiting from surgery. PATIENTS AND METHODS: Ninety patients with previously untreated, potentially operable stage IIIA (mediastinoscopically pN2) NSCLC received three cycles of docetaxel 85 mg/m2 day 1 plus cisplatin 40 mg/m2 days 1 and 2, with subsequent surgical resection. RESULTS: Administered dose-intensities were docetaxel 85 mg/m2/3 weeks (range, 53 to 96) and cisplatin 95 mg/m2/3 weeks (range, 0 to 104). The 265 cycles were well tolerated, and the overall response rate was 66% (95% confidence interval [CI], 55% to 75%). Seventy-five patients underwent tumor resection with positive resection margin and involvement of the uppermost mediastinal lymph node in 16% and 35% of patients, respectively (perioperative mortality, 3%; morbidity, 17%). Pathologic complete response occurred in 19% of patients with tumor resection. In patients with tumor resection, downstaging to N0-1 at surgery was prognostic and significantly prolonged event-free survival (EFS) and overall survival (OS; P =.0001). At median follow-up of 32 months, the median EFS and OS were 14.8 months (range, 2.4 to 53.4) and 33 months (range, 2.4 to 53.4), respectively. Local relapse occurred in 27% of patients with tumor resection, with distant metastases in 37%. Multivariate analyses identified mediastinal clearance (hazard ratio, 0.22; P =.0003) and complete resection (hazard ratio, 0.26; P =.0006) as strongly prognostic for increased survival. CONCLUSION: Neoadjuvant docetaxel-cisplatin is effective and tolerable in stage IIIA pN2 NSCLC. Resection is recommended only for patients with mediastinal downstaging after chemotherapy.
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Objective: Although 24-hour arterial blood pressure can be monitored in a free-moving animal using pressure telemetric transmitter mostly from Data Science International (DSI), accurate monitoring of 24-hour mouse left ventricular pressure (LVP) is not available because of its insufficient frequency response to a high frequency signal such as the maximum derivative of mouse LVP (LVdP/dtmax and LVdP/dtmin). The aim of the study was to develop a tiny implantable flow-through LVP telemetric transmitter for small rodent animals, which can be potentially adapted for human 24 hour BP and LVP accurate monitoring. Design and Method: The mouse LVP telemetric transmitter (Diameter: _12 mm, _0.4 g) was assembled by a pressure sensor, a passive RF telemetry chip, and to a 1.2F Polyurethane (PU) catheter tip. The device was developed in two configurations and compared with existing DSI system: (a) prototype-I: a new flow-through pressure sensor with wire link and (b) prototype-II: prototype-I plus a telemetry chip and its receiver. All the devices were applied in C57BL/6J mice. Data are mean_SEM. Results: A high frequency response (>100 Hz) PU heparin saline-filled catheter was inserted into mouse left ventricle via right carotid artery and implanted, LV systolic pressure (LVSP), LVdP/dtmax, and LVdP/dtmin were recorded on day2, 3, 4, 5, and 7 in conscious mice. The hemodynamic values were consistent and comparable (139_4 mmHg, 16634_319, - 12283_184 mmHg/s, n¼5) to one recorded by a validated Pebax03 catheter (138_2mmHg, 16045_443 and -12112_357 mmHg/s, n¼9). Similar LV hemodynamic values were obtained with Prototype-I. The same LVP waveforms were synchronically recorded by Notocord wire and Senimed wireless software through prototype-II in anesthetized mice. Conclusion: An implantable flow-through LVP transmitter (prototype-I) is generated for LVP accurate assessment in conscious mice. The prototype-II needs a further improvement on data transmission bandwidth and signal coupling distance to its receiver for accurate monitoring of LVP in a freemoving mouse.
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The problem of small Island Developing States (SIDS) is quite recent, end of the 80s and 90s, still looking for a theoretical consolidation. SIDS, as small states in development, formed by one or several islands geographically dispersed, present reduced population, market, territory, natural resources, including drinkable water, and, in great number of the cases, low level of economic activity, factors that together, hinder the gathering of scale economies. To these diseconomies they come to join the more elevated costs in transports and communications which, allies to lower productivities, to a smaller quality and diversification of its productions, which difficult its integration in the world economy. In some SIDS these factors are not dissociating of the few investments in infrastructures, in the formation of human resources and in productive investments, just as it happens in most of the developing countries. In ecological terms, many of them with shortage of natural resources, but integrating important ecosystems in national and world terms, but with great fragility relatively to the pollution action, of excessive fishing, of uncontrolled development of tourism, factors that, conjugated and associated to the stove effect, condition the climate and the slope of the medium level of the sea water and therefore could put in cause the own survival of some of them. The drive to the awareness of the international community towards its problems summed up with the accomplishment by the United Nations in the Barbados’s Conference, 1994 where the right to the development was emphasized, through the going up the appropriate strategies and the Programme of Action for the Sustainable Development of the SIDS. The orientation of the regional and international cooperation in that sense, sharing technology (namely clean technology and control and administration environmental technology), information and creation of capacity-building, supplying means, including financial resources, creating non discriminatory and just trade rules, it would drive to the establishment of a world system economically more equal, in which the production, the consumption, the pollution levels, the demographic politics were guided towards the sustainability. It constituted an important step for the recognition for the international community on the specificities of those states and it allowed the definition of a group of norms and politics to implement at the national, regional and international level and it was important that they continued in the sense of the sustainable development. But this Conference had in its origin previous summits: the Summit of Rio de Janeiro about Environment and Development, accomplished in 1992, which left an important document - the Agenda 21, in the Conference of Stockholm at 1972 and even in the Conference of Ramsar, 1971 about “Wetlands.” CENTRO DE ESTUDOS AFRICANOS Occasional Papers © CEA - Centro de Estudos Africanos 4 Later, the Valletta Declaration, Malta, 1998, the Forum of Small States, 2002, get the international community's attention for the problems of SIDS again, in the sense that they act to increase its resilience. If the definition of “vulnerability” was the inability of the countries to resist economical, ecological and socially to the external shocks and “resilience” as the potential for them to absorb and minimize the impact of those shocks, presenting a structure that allows them to be little affected by them, a part of the available studies, dated of the 90s, indicate that the SIDS are more vulnerable than the other developing countries. The vulnerability of SIDS results from the fact the they present an assemblage of characteristics that turns them less capable of resisting or they advance strategies that allow a larger resilience to the external shocks, either anthropogenic (economical, financial, environmental) or even natural, connected with the vicissitudes of the nature. If these vulnerability factors were grouped with the expansion of the economic capitalist system at world level, the economic and financial globalisation, the incessant search of growing profits on the part of the multinational enterprises, the technological accelerated evolution drives to a situation of disfavour of the more poor. The creation of the resilience to the external shocks, to the process of globalisation, demands from SIDS and of many other developing countries the endogen definition of strategies and solid but flexible programs of integrated development. These must be assumed by the instituted power, but also by the other stakeholders, including companies and organizations of the civil society and for the population in general. But that demands strong investment in the formation of human resources, in infrastructures, in investigation centres; it demands the creation capacity not only to produce, but also to produce differently and do international marketing. It demands institutional capacity. Cape Verde is on its way to this stage.