996 resultados para finite differences


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Triatominae are widely recognised for their role as vectors of Trypanosoma cruzi. One of the main biological characteristics of this subfamily is their obligate haematophagous condition. However, previous studies on Belminus herreri and Belminus ferroae suggested that cockroaches are their principal hosts in domiciles. Due to this peculiar behaviour, the aim of this study was to analyse several demographic and reproductive parameters of B. ferroae fed on three different hosts (mice, cockroaches and Rhodnius prolixus) and relate B. ferroae fitness to these alternative hosts. The cohorts were reared under constant conditions. The egg hatching rate was similar for cohorts fed on cockroaches (69.4%) and R. prolixus (63.8%), but was much lower for the cohort fed on mice (16%). The development time from the nymph to adult stage and the average age of first reproduction (α) presented lower values in the cohort fed on cockroaches, which is consistent with the higher population growth rate associated with this host. Demographic parameters [intrinsic rate of natural increase, finite rate of population growth, net reproductive rate and damping ratio] showed statistically significant differences between the cohorts. Analysis of the life history of B. ferroae revealed a higher fitness related to the cockroach. The implications of these results for the origin of the subfamily are discussed.

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Background: The interaction between lipid disturbances and inflammatory markers is not well known in patients on antiretroviral therapy (ART). As nevirapine (NVP) is associated with a better lipid profile than efavirenz (EFV), we investigated the relationships between lipid profiles, lipoprotein subclasses and inflammatory biomarkers in patients with prolonged viral suppression with either NVP or EFV and no obvious clinical inflammation. Methods: 122 clinically stable HIV-infected patients with HIV-1 RNA <20 copies longer than 6 months on NNRTI therapy were studied. 72 (59%) were on EFV and 50 (41%) on NVP. Any potentially inflammatory co-morbid diseases (concurrent viral hepatitis, diabetes, hypertension, chronic liver or renal diseases), or statin treatment, were exclusion criteria. Inflammatory biomarkers included hsCRP, LpPLA2, sCD40L, IL-6, IL-8, t-PA, MCP-1, p-selectin and VCAM-1. Lipoprotein subclass measures (VLDL, LDL, IDL and HDL particle number and size) were obtained by the use of proton nuclear magnetic resonance spectroscopy. Results: 82% were male; median age 45 years. Median CD4 count 550/μL (IQR 324). Median time since HIV diagnosis 96 months (IQR 102) and accumulated time on ART 50 months (IQR 101). Patients on NVP had higher time since HIV diagnosis (126.9 [66.7] vs 91.3 [6.6] months, p=0.008) a prolonged time on ART (89.6 [54.6] vs 62.3 [52.2] months, p=0.01) and were older (47.7 vs 40.7 years, p=0.001) than those on EFV. NVP-treated patients presented increased HDL-c (55.8 [16] vs 48.8 [10.7] mg/dL, p=0.007) and apoA1 levels (153.4 [31.9] vs 141.5 [20.5] mg/dL, p=0.02), and reduced apoB/apoA1 ratio (0.68 [0.1] vs 0.61 [0.1], p=0.003) than EFV-treated patients. No differences in inflammatory markers or lipoprotein subclasses were found between NVP and EFV. In patients with extreme lipid values (less favorable: 75th percentiles of LDL, small/dense LDLp and small HDLp, or more favorable: HDL p75 and apoB/apoA1 ratio p25), no consistent differences in inflammatory biomarkers were found. Conclusions: Patients with prolonged viral suppression on NVP present significantly higher HDL and apoA1 levels and reduced apoB/apoA1 ratios than those on EFV, but no differences were found in lipoprotein particles nor inflammatory biomarkers. Relationships between lipid parameters and inflammatory biomarkers in NNRTItreated patients are complex and do not show a linear relationship in this study.

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Purpose: HIV-infected patients present an increased cardiovascular risk (CVR) of multifactorial origin, usually lower in women than in men. Information by gender about prevalence of modifiable risk factors is scarce. Methods: Coronator is a cross-sectional survey of a representative sample of HIV-infected patients on ART within 10 hospitals across Spain in 2011. Variables include sociodemographics, CVR factors and 10-year CV disease risk estimation (Regicor: Framingham score adapted to the Spanish population). Results: We included 860 patients (76.3% male) with no history of CVD. Median age 45.6 years; 84.1% were Spaniards; 29.9% women were IDUs. Median time since HIV diagnosis for men and women was 10 and 13 years (p=0.001), 28% had an AIDS diagnosis. Median CD4 cell count was 596 cells/mm3, 88% had undetectable viral load. Median time on ART was 91 and 108 months (p=0.017). There was a family history of early CVD in 113 men (17.9%) and 41 women (20.6%). Classical CVR factors are described in the table. Median (IQR) Regicor Score was 3% (2-5) for men and 2% (1-3) for women (p=0.000), and the proportion of subjects with mid-high risk (>5%) was 26.1% for men and 9.4% for women (p=0.000). Conclusions: In this population of HIV-infected patients, women have lower cardiovascular risk than men, partly due to higher levels of HDL cholesterol. Of note is the high frequency of smoking, abdominal obesity and sedentary lifestyle in our population. (Table Presented).

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Understanding the social conditions and immunological characteristics that allow some human immunodeficiency virus (HIV)-exposed patients to remain uninfected represents an on-going challenge. In this study, the socio-demographic and sexual behaviour characteristics and immune activation profiles of uninfected individuals exposed to HIV-infected partners were investigated. A confidential and detailed questionnaire was administered and venous blood was tested using HIV-1/enzyme immunoassays, plasma HIV-1 RNA levels/bDNA and immunophenotyping/flow cytometry to determine the frequencies of CD4 and CD8 T cells expressing activation markers. The data analysis showed significant differences (p < 0.05) for immune parameters in individuals who were uninfected, albeit exposed to HIV-infected partners, compared with unexposed individuals. In particular, the exposed, uninfected individuals had a higher frequency (median, minimum-maximum) of CD4+HLA-DR+ (4.2, 1.8-6.1), CD8+HLA-DR+ (4.6, 0.9-13.7), CD4+CD45RO+ (27.5, 14.2-46.6), CD4+CD45RO+CD62L+ (46.7, 33.9-67.1), CD8+CD45RA+HLA-DR+ (12.1, 3.4-35.8) and CD8+CD45RO+HLA-DR+ (9.0, 3.2-14.8) cells, a decreased percentage of CD8+CD28+ cells (11.7, 4.5-24.0) and a lower cell-surface expression of Fcγ-R/CD16 on monocytes (56.5, 22.0-130.0). The plasma HIV-1 RNA levels demonstrated detectable RNA virus loads in 57% of the HIV-1+ female partners. These findings demonstrate an activation profile in both CD4 and CD8 peripheral T cells from HIV-1 exposed seronegative individuals of serodiscordant couples from a referral centre in Belo Horizonte, state of Minas Gerais.

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Malaria in La Guajira, the most northern state of Colombia, shows two different epidemiological patterns. Malaria is endemic in the municipality of Dibulla whereas in Riohacha it is characterised by sporadic outbreaks. This study aimed to establish whether differences in transmission patterns could be attributed to different vector species. The most abundant adult female species were Anopheles aquasalis, exclusive to Riohacha, and Anopheles darlingi, restricted to Dibulla. Anopheles mosquitoes were identified using morphology and the molecular markers internal transcribed spacer 2 and cytochrome c oxidase I. All specimens (n = 1,393) were tested by ELISA to determine natural infection rates with Plasmodium falciparum and Plasmodium vivax. An. darlingi was positive for P. vivax 210, with an infection rate of 0.355% and an entomological inoculation rate of 15.87 infective bites/person/year. Anopheles albimanus larvae were the most common species in Riohacha, found in temporary swamps; in contrast, in Dibulla An. darlingi were detected mainly in permanent streams. Distinctive species composition and larval habitats in each municipality may explain the differences in Plasmodium transmission and suggest different local strategies should be used for vector control.

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This research investigates differences in the stereotype content of immigrant groups between linguistic regions. We expected that immigrant groups who speak the local language of a specific linguistic region would be perceived as more competitive within this region than in another linguistic region. Further, we expected these differences would underlie regional differences in stereotype content, albeit only for the warmth dimension. Predictions were tested in the two largest linguistic regions of Switzerland. As expected, in the German-speaking region, locals perceived German immigrants as more competitive and thus as less warm, whereas in the French-speaking region, locals perceived French immigrants as more competitive and, consequently, as less warm. So, paradoxically, immigrants with strong integration potential are particularly disliked because they are regarded as direct competitors.

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This article analyzes Folner sequences of projections for bounded linear operators and their relationship to the class of finite operators introduced by Williams in the 70ies. We prove that each essentially hyponormal operator has a proper Folner sequence (i.e. a Folner sequence of projections strongly converging to 1). In particular, any quasinormal, any subnormal, any hyponormal and any essentially normal operator has a proper Folner sequence. Moreover, we show that an operator is finite if and only if it has a proper Folner sequence or if it has a non-trivial finite dimensional reducing subspace. We also analyze the structure of operators which have no Folner sequence and give examples of them. For this analysis we introduce the notion of strongly non-Folner operators, which are far from finite block reducible operators, in some uniform sense, and show that this class coincides with the class of non-finite operators.

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BACKGROUND The possible differences in the disease spectrum and prognosis of HIV infection in women and men is a major point of concern. Women are under-represented in randomized clinical trials and in some cohorts. Discordant results have often been obtained depending on the setting. METHODS We assessed gender differences in clinical and epidemiological features, antiretroviral treatment (ART) exposure and survival in two multicentre cohorts of HIV-positive subjects in Spain: CoRIS-MD and CoRIS. Competing risk regression models were used to assess gender effect on time to start ART and time to first ART change, and a Cox regression model to estimate gender effect on time to death. RESULTS Between January 1996 and December 2008, 1,953 women and 6,072 men naive to ART at study entry were included. The trend analysis over time showed the percentage of women in the younger (<20 years) and older (>50 years) strata increased significantly (P<0.001) from 0.5% and 1.8% in 1996 to 4.9% and 4.2% in 2008, respectively. By competing risk analysis women started ART earlier than men (adjusted subhazard ratio [ASHR] 1.21, 95% CI 1.11, 1.31) in CoRIS cohort, while in CoRIS-MD none of these differences were observed. In both cohorts women showed a shorter time to the first ART change (ASHR 1.10, 95% CI 1.01, 1.19). Pregnancy and patient's/physician's decisions as reasons for changing were more frequent in women than in men in CoRIS. In the Cox regression model, gender was not associated with differences in survival. CONCLUSIONS In two large cohorts in Spain, we observed relevant gender differences in epidemiological characteristics and antiretroviral exposure outcomes, while survival differences were not attributable to gender.

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Genetic crosses in many organisms have shown that alleles of unlinked genes generally assort independently of one another during gamete formation. However, variation in chromosome size may affect the process of meiosis and lead to nonindependent assortment of chromosomes. We therefore examined chromosomes with insertions and found that they preferentially segregated away from the X chromosome during meiosis in Caenorhabditis elegans males. Conversely, chromosomes with deletions preferentially segregated with the X chromosome. The degree of segregation bias was significantly associated with the length of the insertion or deletion. Simulations revealed that this segregation bias leads to genome size reduction in hermaphroditic species, a pattern consistent with differences in genome sizes in the genus Caenorhabditis. These results suggest that insertions and deletions may affect chromosome segregation patterns.

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Kuranishi's fundamental result (1962) associates to any compact complex manifold X&sub&0&/sub& a finite-dimensional analytic space which has to be thought of as a local moduli space of complex structures close to X&sub&0&/sub&. In this paper, we give an analogous statement for Levi-flat CR manifolds fibering properly over the circle by describing explicitely an infinite-dimensional Kuranishi type local moduli space of Levi-flat CR structures. We interpret this result in terms of Kodaira-Spencer deformation theory making clear the likenesses as well as the differences with the classical case. The article ends with applications and examples.

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This paper compares the procedures of local Brazilian companies (those which have plants in Brazil only) with those of international Brazilian companies (which have plants in at least two countries) regarding the patent management. Although there are a lot more variables to consider when examining the issue of patents in companies, this study presents and analyzes the results of a qualitative research on the decision to patent innovations, the choice of countries where to patent and the strategic significance of patents to the company.

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This study explores the role of early-life education for differences in cognitive functioning between men and women aged 60 and older from seven major urban areas in Latin America and the Caribbean. After documenting statistically significant differences in cognitive functioning between men and women for six of the seven study sites, I assess the extent to which these differences can be explained by prevailing male-female differences in education. I decompose predicted male-female differences in cognitive functioning based on various statistical models for later-life cognition and find robust evidence that male-female differences in education are a major driving force behind cognitive functioning differences between older men and women. This study therefore suggests that early-life differences in educational attainment between boys and girls during childhood have a lasting impact on gender inequity in cognitive functioning at older ages. Increases in educational attainment and the closing of the gender gap in education in many countries in Latin America and the Caribbean may thus result in both higher levels and a more gender-equitable distribution of later-life cognition among the future elderly in those countries.