Lutzomyia longipalpis abundance in the city of Posadas, northeastern Argentina: variations at different spatial scales

The distribution of Lutzomyia longipalpis is heterogeneous with a pattern of high abundance areas (HAAs) embedded in a matrix of low abundance areas (LAAs). The objective of this study was to describe the variability in the abundance of Lu. longipalpis at two different spatial levels and to analyse the relationship between the abundance and multiple environmental variables. Of the environmental variables analysed in each household, the condition that best explained the differences in vector abundance between HAA-LAA was the variable "land_grass", with greater average values in the peridomestic environments within the LAA, and the variables "#sp tree", "#pots" and "dist_water" that were higher in the HAA. Of the environmental variables analysed in the patches, the variable "unpaved_streets" was higher in the LAAs and the variable "prop_inf_dogs" was higher in the HAAs. An understanding of the main environmental variables that influence the vector distribution could contribute to the development of strategies for the prevention and control of visceral leishmaniasis (VL). This is the first work in which environmental variables are analysed at the micro-scale in urban areas at the southern edge of the current range of Lu. longipalpis. Our results represent a significant contribution to the understanding of the abundance of the vector in the peridomestic habitats of the region.

HIV/AIDS knowledge among men who have sex with men: applying the item response theory

OBJECTIVE To evaluate the level of HIV/AIDS knowledge among men who have sex with men in Brazil using the latent trait model estimated by Item Response Theory. METHODS Multicenter, cross-sectional study, carried out in ten Brazilian cities between 2008 and 2009. Adult men who have sex with men were recruited (n = 3,746) through Respondent Driven Sampling. HIV/AIDS knowledge was ascertained through ten statements by face-to-face interview and latent scores were obtained through two-parameter logistic modeling (difficulty and discrimination) using Item Response Theory. Differential item functioning was used to examine each item characteristic curve by age and schooling. RESULTS Overall, the HIV/AIDS knowledge scores using Item Response Theory did not exceed 6.0 (scale 0-10), with mean and median values of 5.0 (SD = 0.9) and 5.3, respectively, with 40.7% of the sample with knowledge levels below the average. Some beliefs still exist in this population regarding the transmission of the virus by insect bites, by using public restrooms, and by sharing utensils during meals. With regard to the difficulty and discrimination parameters, eight items were located below the mean of the scale and were considered very easy, and four items presented very low discrimination parameter (< 0.34). The absence of difficult items contributed to the inaccuracy of the measurement of knowledge among those with median level and above. CONCLUSIONS Item Response Theory analysis, which focuses on the individual properties of each item, allows measures to be obtained that do not vary or depend on the questionnaire, which provides better ascertainment and accuracy of knowledge scores. Valid and reliable scales are essential for monitoring HIV/AIDS knowledge among the men who have sex with men population over time and in different geographic regions, and this psychometric model brings this advantage.

Pulmonary tuberculosis in São Luis, State of Maranhão, Brazil: space and space-time risk clusters for death (2008-2012)

INTRODUCTION: The objective was to identify space and space-time risk clusters for the occurrence of deaths in a priority city for the control of tuberculosis (TB) in the Brazilian Northeast. METHODS: Ecological research was undertaken in the City of São Luis/Maranhão. Cases were considered that resulted in deaths in the population living in the urban region of the city with pulmonary TB as the basic cause, between 2008 and 2012. To detect space and space-time clusters of deaths due to pulmonary TB in the census sectors, the spatial analysis scan technique was used. RESULTS: In total, 221 deaths by TB occurred, 193 of which were due to pulmonary TB. Approximately 95% of the cases (n=183) were geocoded. Two significant spatial clusters were identified, the first of which showed a mortality rate of 5.8 deaths per 100,000 inhabitants per year and a high relative risk of 3.87. The second spatial cluster showed a mortality rate of 0.4 deaths per 100,000 inhabitants per year and a low relative risk of 0.10. A significant cluster was observed in the space-time analysis between 11/01/2008 and 04/30/2011, with a mortality rate of 8.10 deaths per 100,000 inhabitants per year and a high relative risk (3.0). CONCLUSIONS: The knowledge of priority sites for the occurrence of deaths can support public management to reduce inequities in the access to health services and permit an optimization of the resources and teams in the control of pulmonary TB, providing support for specific strategies focused on the most vulnerable populations.

Urban distribution of Phlebotominae in a cutaneous leishmaniasis focus, Argentina

Urbanization and vector domestication are currently proposed as factors that contributed to the recent increase of American cutaneous leishmaniasis (ACL). Is likely also urban transmission? Oran is the main city in the Argentinean hyper-endemic area of ACL, and human cases in urban residences are usually reported. In order to assess the spatial distribution of risk, phlebotomine traps were located in different environments of Oran. A total of 7,787 sand flies were captured: Lutzomyia neivai (98.1%), Lutzomyia migonei (1.2%), Lutzomyia cortelezzii (0.7%), and one Lutzomyia shannoni. During the season of transmission (April-May) a single sand fly was obtained in one out of five urban sites, while a trap in a peri-urban pigsty captured up to 2,985 Lu. neivai/night. Captures performed in the other season of vector activity (September-October) revealed that small-scale changes in the pigsty environment resulted in noticeable changes in the abundance of Lu. neivai. In addition, in a new neighbourhood, on the fringe of the city, 1,073 Lu. neivai/site were captured in the forested edge but one in the yard of the houses. Therefore, in this urban ACL focus the human-vector effective contact risk is still associated with peri-urban vegetation and ecotone modifications despite the urban residence of the cases.

Small-scale area effect on species richness and nesting occupancy of cavity-nesting bees and wasps

Small-scale area effect on species richness and nesting occupancy of cavity-nesting bees and wasps. The research was conducted in an urban forest remnant in southeast Brazil. We tested the predictions of the following hypotheses: (1) larger areas present higher species richness of bees and wasps, (2) solitary bees and wasps occupy more nests in larger areas, (3) rare species occupy more nests in smaller areas. We sampled Aculeate bees and wasps using trap nests from February to November 2004. We placed trap nests in sampling units (SU) with different size (25, 100 and 400 m²) located in 6 ha of secondary mesophytic forest. One hundred and thirty-seven trap nests were occupied by seven species of bees and four species of wasps. We found an increase in wasp, but not bee species richness following increase in SU size. Hymenoptera richness (i.e. bees plus wasps) was also greater in larger SU. Both the number and density of occupied nests increased with SU size. The wasp Trypoxylon lactitarse responded significantly to area size, larger SU having more occupied nests. The same pattern was exhibited by the wasp Auplopus militaris, the Megachile bee species, and the bee Anthodioctes megachiloides. Only Trypoxylon sp. was not affected by SU size. Our results show that cavity-nesting bee and wasps respond differently to the area effects. Such findings must be complemented by information on the frequency and dynamics of area colonization and nest occupancy by species of solitary Hymenoptera.

Quantitative Assessment of Soil Physical Quality in Northern China Based on S-theory

ABSTRACT Quantitative assessment of soil physical quality is of great importance for eco-environmental pollution and soil quality studies. In this paper, based on the S-theory, data from 16 collection sites in the Haihe River Basin in northern China were used, and the effects of soil particle size distribution and bulk density on three important indices of theS-theory were investigated on a regional scale. The relationships between unsaturated hydraulic conductivityKi at the inflection point and S values (S/hi) were also studied using two different types of fitting equations. The results showed that the polynomial equation was better than the linear equation for describing the relationships between -log Ki and -logS, and -log Kiand -log (S/hi)2; and clay content was the most important factor affecting the soil physical quality index (S). The variation in the S index according to soil clay content was able to be fitted using a double-linear-line approach, with decrease in the S index being much faster for clay content less than 20 %. In contrast, the bulk density index was found to be less important than clay content. The average S index was 0.077, indicating that soil physical quality in the Haihe River Basin was good.

Interação de átomos leves com clusters de metais de transição

Density Functional Theory (DFT) calculations on the interactions of small atoms (H, C, O, and S) on first-row transition metal clusters were performed. The results show that the adsorption site may vary between the metal surface and the edge of the cluster. The adsorption energies, adatom-nearest neighbor and adatom-metal plane distances were also determined. Finally, the authors present a discussion about the performance of these metals as anodes on solid oxide fuel cells. The results obtained agree with empirical data, indicating that the theoretical model used is adequate

Constitutive laws for strong geometric non-linearity

This paper is divided into two different parts. The first one provides a brief introduction to the fractal geometry with some simple illustrations in fluid mechanics. We thought it would be helpful to introduce the reader into this relatively new approach to mechanics that has not been sufficiently explored by engineers yet. Although in fluid mechanics, mainly in problems of percolation and binary flows, the use of fractals has gained some attention, the same is not true for solid mechanics, from the best of our knowledge. The second part deals with the mechanical behavior of thin wires subjected to very large deformations. It is shown that starting to a plausible conjecture it is possible to find global constitutive equations correlating geometrical end energy variables with the fractal dimension of the solid subjected to large deformations. It is pointed out the need to complement the present proposal with experimental work.

Depressive symptoms and C-reactive protein in a Brazilian urban community

Psychological depression is an independent risk factor for coronary artery disease. C-reactive protein has been implicated as a mediator of the effect of psychological depression. Several studies have found that individuals, especially men, who report higher levels of psychological depression also have higher levels of C-reactive protein. The current study was undertaken to replicate these results in a Brazilian population, in which there is a much wider range of variation in both background characteristics (such as socioeconomic status) and coronary artery disease risk factors. A sample of 271 individuals was interviewed using the Center for Epidemiological Studies Depression Scale. Fasting blood samples were obtained and evaluated for C-reactive protein (assessed by a turbidimetric immunoassay using a Dade Behring kit) analysis in a subsample (N = 258) of individuals. The mean ± SD C-reactive protein for the entire sample was 0.43 ± 0.44, with 0.42 ± 0.48 for men and 0.43 ± 0.42 mg/L for women. Data were analyzed using multiple regression analysis, controlling for age, sex, body mass index, socioeconomic status, tobacco use, and both total cholesterol and low-density lipoprotein cholesterol. Higher reported depressive symptoms were correlated with higher C-reactive protein for men (partial r = 0.298, P = 0.004) and with lower C-reactive protein for women (partial r = -0.154, P = 0.059). The differences in the associations for men and women could be a result of differential effects of sex hormones on stress reactivity and immune response. On the other hand, this difference in the associations may be related to gender differences in the disclosure of emotion and the effect that self-disclosure has on physical health and immune response.

Food production in solidarity economy: an issue that goes beyond laws

Abstract Food production within the context of solidarity economy is an alternative way to offer employment and income for a significant part of the Brazilian population. The purpose of this study was to carry out a business diagnosis in order to evaluate the facilities, the production process and hygiene practices of seven solidarity economy enterprises located in the city of Novo Hamburgo, Southern Brazil, that work with food production and sales. Visits took place at the enterprises and a check-list was used to record data. Although food production happens in places with space and setting restrictions, it guarantees distinctive foods with aggregate value, where handlers follow the whole process, from raw materials selection to sales. Basic hygiene principles are followed, as they guarantee the production of food with quality, which contributes towards income generation for participating families. Specific laws that apply to the characteristics and needs of small-scale food production must be written in order to regulate solidarity economy enterprises.