893 resultados para Model methodology of empirical research in communication


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BACKGROUND: APOBEC3G (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G) has antiretroviral activity associated with the hypermutation of viral DNA through cytosine deamination. APOBEC3G has two cytosine deaminase (CDA) domains; the catalytically inactive amino-terminal domain of APOBEC3G (N-CDA) carries the Vif interaction domain. There is no 3-D structure of APOBEC3G solved by X-ray or nuclear magnetic resonance. METHODOLOGY/PRINCIPAL FINDINGS: We predicted the structure of human APOBEC3G based on the crystal structure of APOBEC2. To assess the model structure, we evaluated 48 mutants of APOBEC3G N-CDA that identify novel variants altering DeltaVif HIV-1 infectivity and packaging of APOBEC3G. Results indicated that the key residue D128 is exposed at the surface of the model, with a negative local electrostatic potential. Mutation D128K changes the sign of that local potential. In addition, two novel functionally relevant residues that result in defective APOBEC3G encapsidation, R122 and W127, cluster at the surface. CONCLUSIONS/SIGNIFICANCE: The structure model identifies a cluster of residues important for packaging of APOBEC3G into virions, and may serve to guide functional analysis of APOBEC3G.

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Pyrimethamine is used as and anti-infectious agent because of its antifolate properties. Its action is synergistic with that of dapsone and sulfamides on Toxoplasma gondii. The goal of the present study was to evaluate the placental transfer of pyrimethamine in an ex vivo model of perfused human placental cotyledon at term. Human placentas were perfused according to the slightly modified method of Schneider. The pyrimethamine fetal transfer rate was approximately 30%, while cotyledon clearance was about 1.8 ml/min. The placental transfer of pyrimethamine seems to be independent of the maternal concentrations of pyrimethamine, suggesting passive diffusion mechanisms or a nonsaturable active transport at the tested concentrations.

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Background: Several studies have been published on the effects of psychotherapy in routine practice. Complementing traditional views summarised as 'dose-effect models', Stiles et al. put forward data consistent with the responsive regulation model underlining the importance of the client's active participant role in defining length of treatment. One may ask what level of change reached by a patient is considered to be the 'good enough level' (GEL) and if it is related to the duration of psychotherapy. Aims: The main objective of the present feasibility trial was to monitor the patient's session-by-session evolution using a self-report questionnaire in order to define the GEL, i.e. the number of sessions necessary for the patient to reach significant change. Method: A total of N=13 patients undergoing psychotherapy in routine practice participated in the study, completing the Outcome Questionnaire - 45.2 (OQ-45), which assesses the symptom level, interpersonal relationships and social role after every psychotherapy session. The data was analysed using multi-level analyses (HLMs). Results: High feasibility of fine-grained assessment of effects of psychotherapy in routine practice in Switzerland was shown; response rates being acceptable; however, detailed analysis of the GEL was not feasible within the short study time-frame. Conclusions: Reflections on the political context of monitoring in the specific case of routine psychiatric practice in Switzerland are discussed.

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The demographic shift underway in Southern Europe requires a revision of some of the fundamental principles of the traditional welfare state. We analyze the evolution of several aspects of welfare and social expenditure over the last two decades. We find that in the context of the present demographic changes and real estate boom current social and pension policy leads to a new distribution of benefits and burdens which is highly intergenerationally unequal. We argue for a revised definition of public policy based on Musgrave's proposition as a possible rule for an intergenerationally fair distribution.

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Objective: To build a theoretical model to configure the network social support experience of people involved in home care. Method: A quantitative approach research, utilizing the Grounded Theory method. The simultaneous data collection and analysis allowed the interpretation of the phenomenon meaning The network social support of people involved in home care. Results: The population passive posture in building their well-being was highlighted. The need of a shared responsibility between the involved parts, population and State is recognized. Conclusion: It is suggested for nurses to be stimulated to amplify home care to attend the demands of caregivers; and to elaborate new studies with different populations, to validate or complement the proposed theoretical model.


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The study aimed to describe how violence is revealed in the production of the Research Group on Gender, Health and Nursing. This is a historical research of qualitative approach, which evaluated the production of the Research Group, through content analysis. The results show gender as a central category in determining violence and health practices. This aspect determines limitations on professional practices of coping, such as the invisibility of the problem. The female autonomy, the use of alcohol and drugs and social vulnerability play an important relation with the phenomenon and the bond is revealed as potentiality of health practices to address the problem. Conclusion: The gender perspective in nursing research is an innovative field and counter-hegemonic, a possibility to assume a meaning of praxis by transforming potential of understanding and modes of intervention in the phenomenon of gender violence.

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INTRODUCTION: Quitting smoking is associated with weight gain, which may threaten motivation to engage or sustain a quit attempt. The pattern of weight gained by smokers treated according to smoking cessation guidelines has been poorly described. We aimed to determine the weight gained after smoking cessation and its predictors, by smokers receiving individual counseling and nicotine replacement therapies for smoking cessation. METHODS: We performed an ancillary analysis of a randomized controlled trial assessing moderate physical activity as an aid for smoking cessation in addition to standard treatment in sedentary adult smokers. We used mixed longitudinal models to describe the evolution of weight over time, thus allowing us to take every participant into account. We also fitted a model to assess the effect of smoking status and reported use of nicotine replacement therapy at each time point. We adjusted for intervention group, sex, age, nicotine dependence, and education. RESULTS: In the whole cohort, weight increased in the first 3 months, and stabilized afterwards. Mean 1-year weight gain was 3.3kg for women and 3.9kg for men (p = .002). Higher nicotine dependence and male sex were associated with more weight gained during abstinence. Age over median was associated with continuing weight gain during relapse. There was a nonsignificant trend toward slower weight gain with use of nicotine replacement therapies. CONCLUSION: Sedentary smokers receiving a standard smoking cessation intervention experience a moderate weight gain, limited to the first 3 months. Older age, male sex, and higher nicotine dependence are predictors of weight gain.

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According to the WHO (World Health Organization) and the European Union, suicide is considered to be a health problem of prime importance and to be one of the principal causes of unnatural death. In Spain, the number of suicides has increased 12% since 2005 . The Research Project “European Regions Enforcing Actions against Suicide (EUREGENAS), funded by the Health Program 2008-2013, has as main objective the description of an integrated model of Mental Health orientated to the prevention of suicide. The differences that allow distinguishing the meaning of prevention in suicide behavior are described and explained through a qualitative methodological strategy and through the creation of discussion groups formed by different groups of health professionals. The results highlight the existing differences between the diverse health professionals who come more in contact with this problem and it shows as well the coincidence of meaning that suicide has to be considered as a priority in the field of health.

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AbstractOBJECTIVEPresenting methodology for transferring knowledge to improve maternal outcomes in natural delivery based on scientific evidence.METHOD: An intervention study conducted in the maternity hospital of Itapecerica da Serra, SP, with 50 puerperal women and 102 medical records from July to November 2014. The PACES tool from Joanna Briggs Institute, consisting of pre-clinical audit (phase 1), implementation of best practice (phase 2) and Follow-up Clinical Audit (phase 3) was used. Data were analyzed by comparing results of phases 1 and 3 with Fisher's exact test and a significance level of 5%.RESULTSThe vertical position was adopted by the majority of puerperal women with statistical difference between phases 1 and 3. A significant increase in bathing/showering, walking and massages for pain relief was found from the medical records. No statistical difference was found in other practices and outcomes. Barriers and difficulties in the implementation of evidence-based practices have been identified. Variables were refined, techniques and data collection instruments were verified, and an intervention proposal was made.CONCLUSIONThe study found possibilities for implementing a methodology of practices based on scientific evidence for assistance in natural delivery.

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We study the quantitative properties of a dynamic general equilibrium model in which agents face both idiosyncratic and aggregate income risk, state-dependent borrowing constraints that bind in some but not all periods and markets are incomplete. Optimal individual consumption-savings plans and equilibrium asset prices are computed under various assumptions about income uncertainty. Then we investigate whether our general equilibrium model with incomplete markets replicates two empirical observations: the high correlation between individual consumption and individual income, and the equity premium puzzle. We find that, when the driving processes are calibrated according to the data from wage income in different sectors of the US economy, the results move in the direction of explaining these observations, but the model falls short of explaining the observed correlations quantitatively. If the incomes of agents are assumed independent of each other, the observations can be explained quantitatively.

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Purpose: We generated genetically engineered pigs expressing the human dominant GUCY2DE837D/R838S allele to modelize cone dystrophy. After a functional follow-up showing reduced photopic ERG responses (ARVO 2011), we analyzed the eyes by immunohistochemistry and revealed retinal modifications in the transgenic group. Methods: Lentiviral vectors encoding the human double mutant GUCY2DE837D/R838S cDNA under the control of a portion of the pig arrestin-3 promoter (Arr3) were produced and used for lentiviral-mediated transgenesis in pigs. Animals were regularly submitted to behavioral and functional investigations and were sacrificed at 4, 7, 15 and 18 months of age for histological and RT-PCR analyses. Retinal markers were used to evaluate the retinal status of eleven transgenic pigs and 6 non-transgenic controls. The expression of the mutant cDNA was also assayed by RT-PCR. Results: A significant increase in the number of displaced nuclei in the outersegment layer is observed in transgenic animals compared to control animals independently of their age. Part of these nuclei originate from cones as demonstrated by colocalization with cone markers. No significant change in the ONL thickness (central and peripheral retina) was measured between 4 and 18 months of age, showing a slow progression of the disease in the transgenic pigs within this time-frame. Conclusions: Arr3-GUCY2DE837D/R838S pigs show signs of retinal abnormality with slow progression which parallels the loss of photopic function. Further characterization of this model should help to elucidate the molecular mechanisms underlying the disease evolution.

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Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research.

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This paper reconsiders the empirical evidence on the asymmetricoutput effects of monetary policy. Asymmetric effects is a common feature ofmany theoretical models, and there are many different versions of suchasymmetries. We concentrate on the distinctions between positive andnegative money-supply changes, big and small changes in money-supply, andpossible combinations of the two asymmetries. Earlier research has foundempirical evidence in favor of the former of these in US data. Using M1 asthe monetary variable we find evidence in favor of neutrality of big shocksand non-neutrality of small shocks. The results may, however, be affected bystructual instability of M1 demand. Thus, we substitute M1 with the federalfunds rate. In these data we find that only small negative shocks affectreal aggregate activity. The results are interpreted in terms of menu-costmodels.

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This paper presents a dynamic choice model in the attributespace considering rational consumers that discount the future. In lightof the evidence of several state-dependence patterns, the model isfurther extended by considering a utility function that allows for thedifferent types of behavior described in the literature: pure inertia,pure variety seeking and hybrid. The model presents a stationaryconsumption pattern that can be inertial, where the consumer only buysone product, or a variety-seeking one, where the consumer buys severalproducts simultane-ously. Under the inverted-U marginal utilityassumption, the consumer behaves inertial among the existing brands forseveral periods, and eventually, once the stationary levels areapproached, the consumer turns to a variety-seeking behavior. An empiricalanalysis is run using a scanner database for fabric softener andsignificant evidence of hybrid behavior for most attributes is found,which supports the functional form considered in the theory.