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21.
The Guanaco (Lama guanicoe) has suffered a progressive decline in numbers because of unregulated hunting and poaching by an assumed competition with sheep. Inadequate livestock management, including keeping sheep numbers above carrying capacity, has led to a degradation of the Patagonian steppe. Recently, interest has grown towards a reduction in sheep density and diversification of extractive activities. Guanaco populations could be potentially amenable to a number of sustainable uses. Our aim was to investigate the factors that determine guanaco distribution in southern Argentine Patagonia and to generate a predictive cartography at the regional scale. We hypothesized that guanaco distribution could be determined by primary productivity, terrain ruggedness, human disturbance and poaching, and competition with livestock. Guanaco surveys were performed from vehicles using a road survey method. To analyze the relationship between guanaco occurrence and potential predictors we built Generalized Additive Models (GAMs) using a binomial error and a logistic link. We found that guanaco occurrence increased in the less productive and remote areas, far from cities and oil camps, and decreased in regions with high sheep density. These results suggest that guanacos tend to occur where human pressure is lower. One way to promote guanaco conservation would be to highlight the economic value of guanacos under the regulations imposed by a sustainable exploitation of their populations. The predictive models developed here could be a useful tool for the implementation of conservation and management programs at the regional scale.  相似文献   
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Insects trigger a multifaceted innate immune response to fight microbial infections. We show that in the yellow mealworm, Tenebrio molitor, septic injuries induce the synthesis of N-beta-alanyldopamine (NBAD), which is known as the main sclerotization precursor of insect brown cuticles. We demonstrate that NBAD synthase is induced in the epidermis of the mealworm and of the Medfly, Ceratitis capitata, by infection with Escherichia coli. Our results indicate that synthesis of NBAD seems to be a novel component of the overall innate immune response in insects.  相似文献   
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Journal of Applied Phycology - The batch production of Chlorella vulgaris and its potential to profit the remnant nutritional components from ricotta cheese whey (RCW) were evaluated. From a first...  相似文献   
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Biodiversity and Conservation - Understanding the link between biodiversity, ecosystem services and human well-being is necessary to work towards a sustainable use of agroecosystems and the...  相似文献   
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Background

The Caatinga (dry land vegetation) is one of the most characteristic vegetation types in northeastern Brazil. It occupies a large percentage of the semi-arid region there, and generally supports two major types of economic activity: seasonal agriculture and the harvesting of plant products. However, very little information is available concerning the interaction of people with the plants of the Caatinga.

Methods

A study was undertaken with the participation of 31 adults from a rural community in the state of Pernambuco, Brazil, in order to analyze the patterns of use of medicinal plant resources, and to test a number of hypotheses concerning their use and local knowledge about them. The sources of medicinal plants used by the local community, the differences in oral information concerning the use of plants with their effective uses, and the role of exotic plants in local folk medicine practices were examined.

Results

Forty-eight plant species were cited as having medicinal uses, of which 56.25% are native to the Caatinga region. The patterns of harvesting and the importance of these trees and shrubs as medicinal plants seem to be compatible with a hypothesis based on the seasonal availability of plant resources. There is no direct correlation between known medicinal plants and those used by the local population, which agrees with observations made in different tropical regions. However, this observation was not interpreted in terms of the idea of "erosion" of knowledge (commonly used to explain this lack of correlation), but rather to propose two new concepts: "mass knowledge" and "stock knowledge".

Conclusion

Native plants are a very significant component of locally used medicinal plants, although exotic plants are important for treating specific health problems – which leads the proposal of a hypothesis of diversification.  相似文献   
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Galectins, a family of mammalian lectins, have emerged as key regulators of the immune response. We previously demonstrated that galectin (Gal)-8, from the tandem-repeat subgroup, exerts two well-defined effects on mouse naive peripheral CD4 T cells: Ag-specific costimulation and Ag-independent proliferation. These stimulatory signals on naive T cells have not been described for any other Gal. Therefore, we investigated whether Gal-1 and Gal-3, two prominent members of the Gal family, share the stimulatory effects exerted by Gal-8 on naive T cells. We found that Gal-1 costimulated Ag-specific T cell responses similarly to Gal-8, as evaluated in the DO11.10 TCR(OVA)-transgenic mouse model, by acting simultaneously on APCs and target CD4 T cells. In contrast, Gal-3 failed to costimulate Ag-specific T cell responses; moreover, it antagonized both Gal-1 and Gal-8 signals. We observed that both Gal-1 and Gal-3 were unable to induce Ag-independent proliferation; however, when two Gal-1 molecules were covalently fused, the resulting chimeric protein efficiently promoted proliferation. This finding indicates that Gal-1 might eventually induce proliferation and, moreover, stresses the requirement of a tandem-repeat structure. Remarkably, a single dose of recombinant Gal-1 or Gal-8 administered together with a suboptimal Ag dose to DO11.10 mice strengthened weak responses in vivo. Taken together, these findings argue for the participation of Gals in the initiation of the immune response and allow the postulation of these lectins as enhancers of borderline Ag responses, thus representing potential adjuvants for vaccine formulations.  相似文献   
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We evaluated the spider diversity of a tropical montane cloud forest understory in two nearby sites with different degree of human disturbance at the Biosphere Reserve Volcán Tacaná, Chiapas, Mexico. The study was conducted over a 24 days period distributed in 6 months in 2009, covering dry and rainy seasons. A total of 8,370 spiders (1,208 adults and 7,162 juveniles) were collected. Determined specimens (7,747) represented 112 species and morphospecies, 71 genera and 22 families. The results showed that human disturbance has an influence on spider communities: species richness was significantly higher in the preserved site as regards to the disturbed site. Despite their proximity, the composition of spider communities showed only a moderate similarity between the two sites. No differences in abundance were found among sites when considering the whole sample, but sites differed clearly when seasons were analyzed separately. The rainy season had a negative effect on the abundance of spiders in the preserved site. Although the spider community structure was very similar between sites, there was a trend towards a greater species evenness in the preserved site for the whole sampling period and for the dry season.  相似文献   
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Background and aimComplications of diabetes comprise the leading cause of death in Mexico. We aimed to describe the characteristics of management and achievement of therapeutic targets in Mexican patients with diabetes mellitus.MethodsWe analyzed data from 2642 Mexican patients with type 1 (T1D, n = 203, 7.7%) and type 2 diabetes (T2D, n = 2439, 92.3%) included in the third wave of the International Diabetes Management Practices Study.ResultsOf T2D patients, 63% were on oral glucose-lowering drugs (OGLD) exclusively (mostly metformin), 11% on insulin, 22% on OGLD plus insulin, and 4% on diet and exercise exclusively. T2D patients on insulin were more likely to be trained on diabetes, but they were older, had worse control, longer disease duration and more chronic complications than patients on OGLD only. Glycated hemoglobin (HbA1c) < 7% was achieved by 21% and 37% of T1D and T2D patients, respectively. Only 5% of T1D and 3% of T2D attained the composite target of HbA1c < 7%, blood pressure < 130/80 mmHg and low-density lipoprotein cholesterol < 100 mg/dl. T1D patients had less macrovascular but more microvascular complications, compared with T2D patients. Late complications increased with disease duration, so that about 80% of patients after 20 years of diagnosis have at least one late complication. Reaching the target HbA1c < 7% was associated with a reduced number of microvascular but not with less macrovascular complications.ConclusionA great proportion of these Mexican patients with diabetes did not reach therapeutic targets. Insulin was used mostly in complicated cases with advanced disease.  相似文献   
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