95 research outputs found
Renewable energy system for an isolated sustainable social centre
This paper describes the development of the power converters and control algorithms to implement an isolated microgrid based in renewable energy sources used to feed a Sustainable Social Centre in a remote place. The microgrid is designed to work with photovoltaic panels, micro wind and micro-hydro turbines, or even with diesel generators. The control system of the power converters is totally digital and implemented by means of a TMS320f28335 Digital Signal Controller (DSC) from Texas Instruments. One of the most im-portant requirements imposed for the microgrid power system is the capability of providing a sinusoidal supply voltage with low harmonic distortion even in the presence of non linear electrical loads. The hardware topologies and the digital control systems of the power converters are evaluated through experimental results obtained with a developed laboratory prototype. This work is focused in the DC AC converter of the renewable energy system for the isolated Sustainable Centre.(undefined
The Health and Future of the Six Hare Species in Europe: A Closer Look at the Iberian Hare
Although there are around 40 species of hares in the world divided into three different genera (Lepus, Caprolagus, and Pronolagus), only six species inhabit Europe, all belonging to genus Lepus. The conservation status of these six species was recently revised in the International Conservation Union (IUCN) Red List of Threatened Species. Lepus castroviejoi and L. corsicanus were attributed the status of “vulnerable”. The other four species, L. europaeus, L. timidus, L. capensis, and L. granatensis, were considered of “least concern” although a declining trend was recognized for the last two species’ wild populations. Here we review the major threats to the hare species in Europe, with emphasis on infectious diseases. Furthermore, we present the sanitary data regarding the Iberian hare populations from Portugal, which were severely affected by the emergence of a naturally occurring recombinant myxoma virus (MYXV), first reported in mid-2018. The recent detection in 2019 of a leporid herpesvirus (LeHV-5), which pathogenicity appears to be exacerbated in MYXV-infected hares, brings additional concerns to the health and conservation of the Iberian hare
A supramolecular proposal of lignin structure and its relation with the wood properties
Regionalização da saúde: (in)visibilidade e (i)materialidade da universalidade e integralidade em saúde no trânsito de institucionalidades
Para que servem os inventários de fauna?
Inventários de fauna acessam diretamente a diversidade de uma localidade, em um determinado espaço e tempo. Os dados primários gerados pelos inventários compõem uma das ferramentas mais importantes na tomada de decisões a respeito do manejo de áreas naturais. Entretanto, vários problemas têm sido observados em diversos níveis relacionados aos inventários de fauna no Brasil e vão desde a formação de recursos humanos até a ausência de padronização, de desenho experimental e de seleção de métodos inadequados. São apresentados estudos de caso com mamíferos, répteis, anfíbios e peixes, nos quais são discutidos problemas como variabilidade temporal e métodos para detecção de fauna terrestre, sugerindo que tanto os inventários quanto os programas de monitoramento devam se estender por prazos maiores e que os inventários devem incluir diferentes metodologias para que os seus objetivos sejam plenamente alcançados.Inventories of fauna directly access the diversity of a locality in a certain period of time. The primary data generated by these inventories comprise one of the most important steps in decisions making regarding the management of natural areas. However, several problems have been observed at different levels related to inventories of fauna in Brazil, and range from the training of humans to the lack of standardization of experimental design and selection of inappropriate methods. We present case studies of mammals, reptiles, amphibians and fishes, where they discussed issues such temporal variability and methods for detection of terrestrial fauna, suggesting that both inventories and monitoring programs should be extended for longer terms and that inventories should include different methodologies to ensure that their goals are fully achieved
Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli
Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts. Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins. Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
Efeitos da aplicação de doses de nitrogênio e densidades de plantio sobre os rendimentos de espigas verdes e de grãos de milho
Survivorship of Anopheles darlingi (Diptera: Culicidae) in Relation with Malaria Incidence in the Brazilian Amazon
We performed a longitudinal study of adult survival of Anopheles darlingi, the most important vector in the Amazon, in a malarigenous frontier zone of Brazil. Survival rates were determined from both parous rates and multiparous dissections. Anopheles darlingi human biting rates, daily survival rates and expectation of life where higher in the dry season, as compared to the rainy season, and were correlated with malaria incidence. The biting density of mosquitoes that had survived long enough for completing at least one sporogonic cycle was related with the number of malaria cases by linear regression. Survival rates were the limiting factor explaining longitudinal variations in Plasmodium vivax malaria incidence and the association between adult mosquito survival and malaria was statistically significant by logistic regression (P<0.05). Survival rates were better correlated with malaria incidence than adult mosquito biting density. Mathematical modeling showed that P. falciparum and P. malariae were more vulnerable to changes in mosquito survival rates because of longer sporogonic cycle duration, as compared to P. vivax, which could account for the low prevalence of the former parasites observed in the study area. Population modeling also showed that the observed decreases in human biting rates in the wet season could be entirely explained by decreases in survival rates, suggesting that decreased breeding did not occur in the wet season, at the sites where adult mosquitoes were collected. For the first time in the literature, multivariate methods detected a statistically significant inverse relation (P<0.05) between the number of rainy days per month and daily survival rates, suggesting that rainfall may cause adult mortality
Para além de um prefácio: ditadura e democracia no diálogo entre Antonio Candido e Sérgio Buarque de Holanda
- …