995 resultados para Transition rates
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Abstract: We analyze the realized stock-bond correlation. Gradual transitions between negative and positive stock-bond correlation is accommodated by the smooth transition regression (STR) model. The changes in regime are de ned by economic and financial transition variables. Both in sample and out-of- sample results document that STR models with multiple transition variables outperform STR models with a single transition variable. The most important transition variables are the short rate, the yield spread, and the VIX volatility index. Keywords: realized correlation; smooth transition regressions; stock-bond correlation; VIX index JEL Classifi cations: C22; G11; G12; G17
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Aim: This study examines the transition from fertility to obstetrical care of women who conceived through IVF. Materials & methods: 33 women filled out questionnaires before IVF, during pregnancy and after birth on infertility stress, maternal adjustment and depressive symptoms. During pregnancy, they participated in an interview about their emotional experiences regarding the transition. Responses were sorted into three categories: Autonomy, Dependence and Avoidance. Results: Exploratory results show that 51.5% of women had no difficulties making the transition (Autonomy), 21.2% had become dependent (Dependence) and 27.3% had distanced themselves from the specialists (Avoidance). Women who became dependent had more trouble adjusting to motherhood and more depressive symptoms. Conclusion: Difficulty making the transition may be linked to decreased ability to adjust to motherhood and more postpartum depressive symptoms.
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In a visceral leishmaniasis endemic locality of northeast of Brasil where all settlements were treated with cypermethrin, a follow-up of Lutzomyia longipalpis populations was carried out by regular collections. The residual effect of the insecticide was studied using biological assays on three different types of walls. The results showed that the insecticides had an effect on intradomiciliar Lu. longipalpis populations limited to two months, and had no significant effect on peridomiciliar vector populations. The mortality rates of the tested sandflies were variable according to the type of wall. The decreasing of the insecticide effect was marked since the 3rd month, and mortality rates were identical whatever the type of wall since the 4th month. Unsufficient residual effect was detected after the 4th month.
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Transmembrane receptor-kinases are widespread throughout eukaryotes and their activities are known to regulate all kinds of cellular responses in diverse organs and cell types. In order to guarantee the correct amplitude and duration of signals, receptor levels at the cellular surface need to be tightly controlled. The regulation of receptor degradation is the most direct way to achieve this and elaborate mechanisms are in place to control this process. Therefore, the rate of receptor degradation is a parameter of central importance for understanding the dynamics of a signal transduction cascade. Unfortunately, degradation of transmembrane receptors is a complicated multistep process that involves internalization from the plasma membrane, invagination into the lumen of endosomal compartments, and finally fusion with the vacuole for degradation by vacuolar proteases. Therefore, degradation should be measured in an as noninvasive way as possible, such as not to interfere with the complicated transport processes. Here, a method for minimally invasive, in vivo turn-over measurements in intact organs is provided. This technique was used for quantifying the turn-over rates of the Brassinosteroid receptor kinase BRI1 (BRASSINOSTEROID INSENSITIVE 1) in Arabidopsis thaliana root meristems. Pulse-chase expression of a fluorescently labeled BRI1 variant was used and its turn-over rate was determined by quantitative confocal microscopy. This method is well suited to measure turn-over of transmembrane kinases, but can evidently be extended to measure turn-over of any types of transmembrane proteins.
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OBJECTIVE: To describe CD4 and HIV RNA changes during treatment resumption (TR) after treatment interruption (TI) compared with response to first highly active antiretroviral therapy (HAART) and to investigate predictors. METHODS: Using Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE) data, we identified subjects who interrupted first HAART, not initiated during primary infection. We estimated rate of CD4 change during TR and time from TR to HIV RNA<500 copies per milliliter and subsequent rebound and factors associated with these outcomes. RESULTS: Of 281 persons treated for median 18.4 months before interrupting, 259 resumed HAART. CD4 increases in the first 3 months on HAART were similar pre-TI and post-TI but after 3 months were significantly higher during pre-TI HAART, with median +106 and +172 cells per microliter at 3 and 18 months, respectively, during initial HAART compared with +99 and +142 cells per microliter during post-TI HAART, respectively. Subjects with lower CD4 counts at TI, aged older than 40 years, and those resuming the same HAART as their pre-TI regimen had lower CD4 increases during the first 3 months of TR. The majority (86%) of individuals reinitiating therapy achieved HIV RNA<500 copies per milliliter. CONCLUSIONS: Immune reconstitution after TI is generally poorer than after first HAART, particularly for patients aged older than 40 years at TI and those with poorer immunological responses to pre-TI HAART. Reinitiation of the same HAART regimen as pre-TI also seems to have unfavorable outcomes.
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Ectoparasitic batflies were studied on 12 species of phyllostomid bats, by making 35 nightly collections of bats using mist nets at the "Panga" Ecological Reservation near Uberlândia, State of Minas Gerais, southeastern Brazil, from August 1989 to July 1990. Eleven species of Streblidae and one of Nycteribiidae were collected on 12 species of bats. Prevalence of ectoparasitic flies was lower than those reported by other authors for the New World and may be the result of the lack of caves in the study area, causing bats to roost in less favorable locations, forming smaller colonies. The fly, Trichobius joblingi Wenzel, was found on Carollia perspicillata (Linnaeus), showing preference for adult male bats. This could be explained by the predominance of males in the bat colonies, and by the fact that females rest in isolation during the reproductive period making them less exposed to the parasites. The streblid flies, Aspidoptera falcata Wenzel and Megistopoda proxima (Séguy), were found on Sturnira lilium (Geoffroy). A. falcata occurred mainly on young and adult females, whereas M. proxima did not show any preferences relative to the reproductive condition of the host. Ecological factors are important in determining differential numbers of parasites occurring on the different sexes, ages and reproductive state of the hosts.
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OBJECTIVES: To examine the association between socioeconomic status (SES) and several cardiovascular disease risk factors (CVRFs) and to assess whether this association has changed over a 15-year observation period. METHODS: Three independent population-based surveys of CVRFs were conducted in representative samples of all adults aged 25-64 years in the Seychelles, a small island state located east to Kenya, in 1989 (N=1081), 1994 (N=1067) and 2004 (N=1255). RESULTS: Among men, current smoking and heavy drinking were more prevalent in the low versus the high SES group, and obesity was less prevalent. The socioeconomic gradient in diabetes reversed over the study period from lower prevalence in the low versus the high SES group to higher prevalence in the low SES group. Hypercholesterolemia was less prevalent in the low versus the high SES group in 1989 but the prevalence was similar in the two groups in 2004. Hypertension showed no consistent socioeconomic pattern. Among women, the SES gradient in smoking tended to reverse over time from lower prevalence in the low SES group to lower prevalence in the high SES group. Obesity and diabetes were more common in the low versus the high SES group over the study period. Heavy drinking, hypertension and hypercholesterolemia were not socially patterned among women. CONCLUSION: The prevalence of several CVRFs was higher in low versus high SES groups in a rapidly developing country in the African region, and an increase of the burden of these CVRFs in the most disadvantaged groups of the population was observed over the 15 years study period.
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BACKGROUND: A growing number of case reports have described tenofovir (TDF)-related proximal renal tubulopathy and impaired calculated glomerular filtration rates (cGFR). We assessed TDF-associated changes in cGFR in a large observational HIV cohort. METHODS: We compared treatment-naive patients or patients with treatment interruptions > or = 12 months starting either a TDF-based combination antiretroviral therapy (cART) (n = 363) or a TDF-sparing regime (n = 715). The predefined primary endpoint was the time to a 10 ml/min reduction in cGFR, based on the Cockcroft-Gault equation, confirmed by a follow-up measurement at least 1 month later. In sensitivity analyses, secondary endpoints including calculations based on the modified diet in renal disease (MDRD) formula were considered. Endpoints were modelled using pre-specified covariates in a multiple Cox proportional hazards model. RESULTS: Two-year event-free probabilities were 0.65 (95% confidence interval [CI] 0.58-0.72) and 0.80 (95% CI 0.76-0.83) for patients starting TDF-containing or TDF-sparing cART, respectively. In the multiple Cox model, diabetes mellitus (hazard ratio [HR] = 2.34 [95% CI 1.24-4.42]), higher baseline cGFR (HR = 1.03 [95% CI 1.02-1.04] by 10 ml/min), TDF use (HR = 1.84 [95% CI 1.35-2.51]) and boosted protease inhibitor use (HR = 1.71 [95% CI 1.30-2.24]) significantly increased the risk for reaching the primary endpoint. Sensitivity analyses showed high consistency. CONCLUSION: There is consistent evidence for a significant reduction in cGFR associated with TDF use in HIV-infected patients. Our findings call for a strict monitoring of renal function in long-term TDF users with tests that distinguish between glomerular dysfunction and proximal renal tubulopathy, a known adverse effect of TDF.
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A shift from large to small average sizes was observed in Triatoma infestans and Rhodnius domesticus between field and domestic (or laboratory) conditions of life. It was more pronounced in the female specimens, leading to a subsequent reduction of sexual size dimorphism. This feature is discussed in terms of genetic and populational changes occurring from natural to artificial habitats, in particular those related to population densities. Sexual size dimorphism is then recommended as a new character to be used in the study of species of Triatominae adapting to domestic ecotopes.
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Number of deaths and age-standardised death rates by type of injury for the following regions and year of occurrence:Republic of Ireland 1982, 1983, 1995-2004Northern Ireland 1982, 1983, 1995-2002England 1996-2003Scotland 1982, 1983, 1995-2004Wales 1996-2003
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Number of hospital discharges and age-standardised discharge rates for emergency hospital admissions for injury by sex and type of injury for the following regions and year:Republic of Ireland 2006Northern Ireland 2006England 2006/07Scotland 2006/07Wales 2006 Numbers and rates are based on official hospital statistics from each region. All regions use International Classification of Disease (ICD) version 10 for hospital discharges in these years. Only emergency inpatient hospital spells with an ICD 10 code in the range S000-T739, T750-T759, T780-T789 (in any diagnostic position) and an ICD10 external cause code in the range V01-Y36 (in any diagnostic position) were included. A hospital spell is an unbroken period of time that a person spends as an inpatient in a hospital. The person may change consultant and/or specialty during a spell but is counted only once. See http://www.injuryobservatory.net/analysis-of-inpatient-admissions-data-f... for more details.
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The sensitivity of parameters that govern the stability of population size in Chrysomya albiceps and describe its spatial dynamics was evaluated in this study. The dynamics was modeled using a density-dependent model of population growth. Our simulations show that variation in fecundity and mainly in survival has marked effect on the dynamics and indicates the possibility of transitions from one-point equilibrium to bounded oscillations. C. albiceps exhibits a two-point limit cycle, but the introduction of diffusive dispersal induces an evident qualitative shift from two-point limit cycle to a one fixed-point dynamics. Population dynamics of C. albiceps is here compared to dynamics of Cochliomyia macellaria, C. megacephala and C. putoria.