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Mansonellosis is an undermapped insect-transmitted disease caused by filarial nematodes that are estimated to infect hundreds of millions of people globally. Despite their prevalence, there are many outstanding questions regarding the general biology and health impacts of the responsible parasites. Historical reports suggest that the Colombian Amazon is endemic for mansonellosis and may serve as an ideal location to pursue these questions in the backdrop of other endemic and emerging pathogens. We deployed molecular and classical diagnostic approaches to survey Mansonella prevalence among adults belonging to indigenous communities along the Amazon River and its tributaries near Leticia, Colombia. Deployment of a loop-mediated isothermal amplification (LAMP) assay on blood samples revealed an infection prevalence of ∼40% for Mansonella ozzardi . This assay identified significantly more infections than blood smear microscopy or LAMP assays performed using plasma, likely reflecting greater sensitivity and the ability to detect low microfilaremias or occult infections. Mansonella infection rates increased with age and were higher among males compared to females. Genomic analysis confirmed the presence of M. ozzardi that clusters closely with strains sequenced in neighboring countries. We successfully cryopreserved and revitalized M. ozzardi microfilariae, advancing the prospects of rearing infective larvae in controlled settings. These data suggest an underestimation of true mansonellosis prevalence, and we expect that these methods will help facilitate the study of mansonellosis in endemic and laboratory settings.

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The marine environment is constantly being impacted by anthropogenic activities. Nowadays, microplastics (MPs) representing one of the most deleterious material among of all substances and material from anthropogenic origin. The Microplastics (MPs) are particles smaller than 5 mm. This study presents information on abundance, distribution, type and colour of microplastics in the bottom sediments of the continental Shelf of Rio de Janeiro State. This area is strongly impacted due to its location in front of one of the most polluted coastal bays in the Brazilian Coastline. It receives untreated sewage from an Ipanema Beach submarine emissary and also a great amount of sediments dredged from Rio de Janeiro Harbour, which strongly influences the distribution of MPs in the area. The analyses detected the presence of MP in 100% of the samples, composed mainly by secondary microplastics, and almost 50% were fibers, followed by plastic films, plastic fragments and pellets. Based on the nature of the sources of the MP, a great variety of colours was shown, dominated by four main colours: blue, white, transparent, and black, this pattern could potentially increase their bioavailability due to resemblance to prey items, especially to visual raptorial species.

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In this paper further information concerning the ecological and biogeographical aspects of scorpionism is presented. Some of the information already outlined in three previous publications (10,14,16) is assessed, and new data given concerning the pattern of distribution presented by Tityus serrulatus in Brazil. Some new ideas are also proposed regarding the possible evolutionary advantages and disadvantages of parthenogenesis versus sexuality in both the short-term and the long-term.

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"With data from a survey applied to random samples of university professors in seven Mexican cities during the late eighties, this article examines professors' opinions on the relations between population, development, and poverty. After reviewing tendencies and arguments on population and development found in [the] literature, it provides three simple typologies of population consciousness, poverty determinants, and best economic development plans for the country. It then studies their relations, and concludes by outlining the type of reasoning in each of the main orientations detected by the analysis." (SUMMARY IN ENG)

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Recently public health problems resulting from scorpion stings have shown an alarming increase in various tropical and subtropical countries such as Brazil, Mexico, Tunisia and Morocco. In some regions of Brazil, particularly in the States of Minas Gerais. Säo Paulo, Bahia, Goiás and the Federal District, more than 6000 scorpion stings with over 100 deaths were reported during a three-year period. In this paper, we attempt to demostrate the effects of human activities on the environment and their consequences on the distribution of dangerous species of scorpions. This topic is discussed in relation to the evolutionary ecology, life history strategies and asexual reproduction of scorpions.

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This article examines interpretations regarding the relationship between means of support and fertility, taking into account views on social reproduction among peasants, with emphasis on the way they are expressed in terms of indicators. The author begins with a brief summary of theories put forth by Malthus, and then examines Neo-Malthusian models which use as an independent variable, the amount of land and as a dependent variable, the number of children. He notes the existence of a positive ratio between these variables, and then demonstrates that in Chayanov's model, the number of children is used as an independent variable, while the idea of a positive ratio with the amount of land is still maintained. He compares these assumptions with those of Palerm, who suggests the existence of an inverse ratio between the amount of land available and fertility; this leads to policy implications contrary to those arising from neo-Malthusian models. The paper ends with a discussion of assumptions about the rationality, motivations, and guiding values the different approaches attribute to economic and demographic behavior among peasants.

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