2,677 research outputs found

    The Stingless Bee Fauna In Brazil (Hymenoptera: Apidae)

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    The stingless bee fauna currently living in Brazil is presented, including geographic records. A total of 242 species described with valid names and about 85 of new ones, affiliated to 29 genera, are registered to the country. The survey is based mainly on the Catalogue of Bees (Moure’s bee Catalogue) and specimens housed in the Camargo Collection – RPSP. An evaluation of the current taxonomic situation and some short comments about the biology of each genus are also included

    Revision of the species of Melipona of the fuliginosa group (Hymenoptera, Apoidea, Apidae, Meliponini)

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    Três espécies são reconhecidas: Melipona (Michmelia) fuliginosa Lepeletier, 1836, de larga distribuição, do Suriname e Guiana Francesa até o sudeste do Brasil e noroeste da Argentina, M. (Michmelia) titania Gribodo, 1893 (revalidado), endêmica do oeste da Amazônia, e M. (Michmelia) fallax sp. nov., do noroeste do Equador até a América Central. Melipona fuliginosa distingue-se pela pilosidade dos tergos metassomáticos II-V, tanto do macho como da operária, densa e plumosa, e pelo primeiro tarsômero da perna III do macho mais largo que longo. Em M. titania e M. fallax sp. nov., a pilosidade dos tergos II-V é escassa e simples, não-plumosa, e o primeiro tarsômero tão longo quanto largo ou mais longo que largo. Operárias de Melipona titania e M. fallax sp. nov. separam-se pela forma do penicilo, que é fortemente sinuoso em M. titania, e nos machos de M. fallax sp. nov. as órbitas internas dos olhos são paralelas, enquanto em M. titania as órbitas são convergentes embaixo. Novos registros geográficos, dados bionômicos e uma chave para identificação das espécies são apresentados. Adicionalmente, são feitos comentários sobre o padrão biogeográfico e sobre as glândulas tergais das rainhas.Three species are recognized: Melipona (Michmelia) fuliginosa Lepeletier, 1836, widely distributed, from Suriname and French Guiana to southeastern Brazil and northwestern Argentina, M. (Michmelia) titania Gribodo, 1893 (revalidated), endemic to western Amazon and M. (Michmelia) fallax sp. nov., from northwestern Ecuador to Central America. Melipona fuliginosa differs from the other species by the pilosity of metasomal terga II-V, dense and plumose, in both male and workers, and the first tarsomere of leg III of the male wider than long. In M. titania and M. fallax sp. nov., the pilosity of terga II-V is scarce and simple, non-plumose, and the first tarsomere of leg III of the male is as long as wide or longer. Workers of Melipona titania and M. fallax sp. nov. differ by the shape of the penicillum, which is strongly sinuous in M. titania, and in the males of M. fallax sp. nov. the internal orbits of the eyes are parallel, while in M. titania the orbits are convergent below. New geographic records, bionomic data and an identification key for the species are presented. In addition, comments are given on geographic patterns and tergal glands of the queens

    Analysis of the potential for hydrogen production in the province of Córdoba, Argentina, from wind resources

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    The potential for hydrogen production from wind resources in the province of Córdoba, second consumer of fossil fuels for transportation in Argentina, is analyzed. Three aspects of the problem are considered: the evaluation of the hydrogen resource from wind power, the analysis of the production costs via electrolysis and the annual requirements of wind energy to generate hydrogen to fuel the vehicular transport of the province. Different scenarios were considered, including pure hydrogen as well as the so-called CNG plus, where hydrogen is mixed with compressed natural gas in a 20% V/V dilution of the former. The potential for hydrogen production from wind resources is analyzed for each department of the province, excluding those regions not suited for wind farms. The analysis takes into account the efficiency of the electrolyzer and the capacity factor of the wind power system. It is concluded that the automotive transportation could be supplied by hydrogen stemming from wind resources via electrolysis. © 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.Fil: Rodríguez, Carlos Ramiro. Universidad Siglo 21; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Riso, M.. Ministerio de Obras y Servicios Públicos del Gobierno de la Provincia de Córdoba. Subsecretaría de Infraestructuras y Programas; ArgentinaFil: Jiménez Yob, G.. Ministerio de Obras y Servicios Públicos del Gobierno de la Provincia de Córdoba. Subsecretaría de Infraestructuras y Programas; ArgentinaFil: Ottogalli, R.. Ministerio de Obras y Servicios Públicos del Gobierno de la Provincia de Córdoba. Subsecretaría de Infraestructuras y Programas; ArgentinaFil: Santa Cruz, R.. Universidad Siglo 21; ArgentinaFil: Aisa, Silvia Elena. Universidad Siglo 21; ArgentinaFil: Jeandrevin, Silvina. Instituto Universitario Aeronautico. Facultad de Ingeniería; Argentina. Mr.technologies S.a; ArgentinaFil: Leiva, Ezequiel Pedro M.. Universidad Nacional de Córdoba. Facultad de Cs.químicas. Departamento de Química Teórica y Computacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

    Discovery of Phytophthora infestans Genes Expressed in Planta through Mining of cDNA Libraries

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    BACKGROUND: Phytophthora infestans (Mont.) de Bary causes late blight of potato and tomato, and has a broad host range within the Solanaceae family. Most studies of the Phytophthora--Solanum pathosystem have focused on gene expression in the host and have not analyzed pathogen gene expression in planta. METHODOLOGY/PRINCIPAL FINDINGS: We describe in detail an in silico approach to mine ESTs from inoculated host plants deposited in a database in order to identify particular pathogen sequences associated with disease. We identified candidate effector genes through mining of 22,795 ESTs corresponding to P. infestans cDNA libraries in compatible and incompatible interactions with hosts from the Solanaceae family. CONCLUSIONS/SIGNIFICANCE: We annotated genes of P. infestans expressed in planta associated with late blight using different approaches and assigned putative functions to 373 out of the 501 sequences found in the P. infestans genome draft, including putative secreted proteins, domains associated with pathogenicity and poorly characterized proteins ideal for further experimental studies. Our study provides a methodology for analyzing cDNA libraries and provides an understanding of the plant--oomycete pathosystems that is independent of the host, condition, or type of sample by identifying genes of the pathogen expressed in planta

    Disentangling the mechanisms shaping the surface ocean microbiota

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    BACKGROUND: The ocean microbiota modulates global biogeochemical cycles and changes in its configuration may have large-scale consequences. Yet, the underlying ecological mechanisms structuring it are unclear. Here, we investigate how fundamental ecological mechanisms (selection, dispersal and ecological drift) shape the smallest members of the tropical and subtropical surface-ocean microbiota: prokaryotes and minute eukaryotes (picoeukaryotes). Furthermore, we investigate the agents exerting abiotic selection on this assemblage as well as the spatial patterns emerging from the action of ecological mechanisms. To explore this, we analysed the composition of surface-ocean prokaryotic and picoeukaryotic communities using DNA-sequence data (16S- and 18S-rRNA genes) collected during the circumglobal expeditions Malaspina-2010 and TARA-Oceans. RESULTS: We found that the two main components of the tropical and subtropical surface-ocean microbiota, prokaryotes and picoeukaryotes, appear to be structured by different ecological mechanisms. Picoeukaryotic communities were predominantly structured by dispersal-limitation, while prokaryotic counterparts appeared to be shaped by the combined action of dispersal-limitation, selection and drift. Temperature-driven selection appeared as a major factor, out of a few selected factors, influencing species co-occurrence networks in prokaryotes but not in picoeukaryotes, indicating that association patterns may contribute to understand ocean microbiota structure and response to selection. Other measured abiotic variables seemed to have limited selective effects on community structure in the tropical and subtropical ocean. Picoeukaryotes displayed a higher spatial differentiation between communities and a higher distance decay when compared to prokaryotes, consistent with a scenario of higher dispersal limitation in the former after considering environmental heterogeneity. Lastly, random dynamics or drift seemed to have a more important role in structuring prokaryotic communities than picoeukaryotic counterparts. CONCLUSIONS: The differential action of ecological mechanisms seems to cause contrasting biogeography, in the tropical and subtropical ocean, among the smallest surface plankton, prokaryotes and picoeukaryotes. This suggests that the idiosyncrasy of the main constituents of the ocean microbiota should be considered in order to understand its current and future configuration, which is especially relevant in a context of global change, where the reaction of surface ocean plankton to temperature increase is still unclear. Video Abstract

    Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

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    In this work, a raw and low cost mineral, ilmenite (FeTiO3), has been tested for the first time as a photocatalyst paired with peroxymonosulfate (HSO5-; PMS) for the inactivation of Enterococcus faecalis as an alternative to conventional treatments to disinfect wastewater for reuse. The influence of some operational parameters such as reagent dosage, catalyst concentration, initial pH, or flow rate was also studied and optimized. After several tests, the scarce pure photoactivity under UV-A was remarked by ilmenite because of its high iron content, which favors photogenerated charge recombination. However, ilmenite activity was highly promoted when combined with low concentrations of PMS and UV-A light, reaching total inactivation of Enterococcus faecalis in 120 min. Quenching tests were performed using methanol, tert-butyl alcohol, furfuryl alcohol, and Cu(II) to assess the main reactive species involved in the disinfection process determining the critical role of both HO·and SO4·- radicals in the process. Finally, the influence of the water matrix was also evaluated by studying the effect of water hardness and the presence of nutrients on the system. Overall, the PMS/Ilmenite/UV-A system yielded promising results with a total removal of Enterococcus faecalis in 120 min. However, it also showed the need for further study and understanding of the disinfection mechanism to achieve the same level of performance in real wastewaterThe "Comunidad de Madrid" supported this research through REMTAVARES S2013/MAE-2716 and S2018/EMT-434

    Cholinergic Signaling Exerts Protective Effects in Models of Sympathetic Hyperactivity-Induced Cardiac Dysfunction

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    Cholinergic control of the heart is exerted by two distinct branches; the autonomic component represented by the parasympathetic nervous system, and the recently described non-neuronal cardiomyocyte cholinergic machinery. Previous evidence has shown that reduced cholinergic function leads to deleterious effects on the myocardium. Yet, whether conditions of increased cholinergic signaling can offset the pathological remodeling induced by sympathetic hyperactivity, and its consequences for these two cholinergic axes are unknown. Here, we investigated two models of sympathetic hyperactivity: i) the chronic beta-adrenergic receptor stimulation evoked by isoproterenol (ISO), and ii) the alpha(2A)/alpha(2C)-drenergic receptor knockout (KO) mice that lack pre-synaptic adrenergic receptors. In both models, cholinergic signaling was increased by administration of the cholinesterase inhibitor, pyridostigmine. First, we observed that isoproterenol produces an autonomic imbalance characterized by increased sympathetic and reduced parasympathetic tone. Under this condition transcripts for cholinergic proteins were upregulated in ventricular myocytes, indicating that non-neuronal cholinergic machinery is activated during adrenergic overdrive. Pyridostigmine treatment prevented the effects of ISO on autonomic function and on the ventricular cholinergic machinery, and inhibited cardiac remodeling. alpha(2A)/alpha(2C)-KO mice presented reduced ventricular contraction when compared to wild-type mice, and this dysfunction was also reversed by cholinesterase inhibition. Thus, the cardiac parasympathetic system and non-neuronal cardiomyocyte cholinergic machinery are modulated in opposite directions under conditions of increased sympathetic drive or ACh availability. Moreover, our data support the idea that pyridostigmine by restoring ACh availability is beneficial in heart disease

    Brain structural covariance networks in obsessive-compulsive disorder: a graph analysis from the ENIGMA Consortium.

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    Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.e. z-score transformed). Global networks were characterized using measures of network segregation (clustering and modularity), network integration (global efficiency), and their balance (small-worldness), and their community membership was assessed. Hub profiling of regional networks was undertaken using measures of betweenness, closeness, and eigenvector centrality. Individually calculated network measures were integrated across the 37 datasets using a meta-analytical approach. These network measures were summated across the network density range of K = 0.10-0.25 per participant, and were integrated across the 37 datasets using a meta-analytical approach. Compared with healthy controls, at a global level, the structural covariance networks of OCD showed lower clustering (P < 0.0001), lower modularity (P < 0.0001), and lower small-worldness (P = 0.017). Detection of community membership emphasized lower network segregation in OCD compared to healthy controls. At the regional level, there were lower (rank-transformed) centrality values in OCD for volume of caudate nucleus and thalamus, and surface area of paracentral cortex, indicative of altered distribution of brain hubs. Centrality of cingulate and orbito-frontal as well as other brain areas was associated with OCD illness duration, suggesting greater involvement of these brain areas with illness chronicity. In summary, the findings of this study, the largest brain structural covariance study of OCD to date, point to a less segregated organization of structural covariance networks in OCD, and reorganization of brain hubs. The segregation findings suggest a possible signature of altered brain morphometry in OCD, while the hub findings point to OCD-related alterations in trajectories of brain development and maturation, particularly in cingulate and orbitofrontal regions

    Immunomodulation From Moderate Exercise Promotes Control of Experimental Cutaneous Leishmaniasis

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    Physical exercise has been described as an important tool in the prevention and treatment of numerous diseases as it promotes a range of responses and adaptations in several biological systems, including the immune system. Studies on the effect of exercise on the immune system could play a critical role in improving public health. Current literature suggests that moderate intensity exercise can modulate the Th1/Th2 dichotomy directing the immune system to a Th1 cellular immune response, which favors the resolution of infections caused by intracellular microorganisms. Leishmaniasis is a group of diseases presenting a wide spectrum of clinical manifestations that range from self-limiting lesions to visceral injuries whose severity can lead to death. The etiological agents responsible for this group of diseases are protozoa of the genus Leishmania. Infections by the parasite Leishmania major in mice (Balb/c) provide a prototype model for the polarization of CD4+ T cell responses of both Th1 (resistance) or Th2 (susceptibility), which determines the progression of infections. The aim of this study was to evaluate the effect of exercise on the development of L. major experimental infections by scanning the pattern of immune response caused by exercise. Groups of Balb/c mice infected with L. major were divided into groups that preformed a physical exercise of swimming three times a week or were sedentary along with treatment or not with the reference drug, meglumine antimoniate. Animals in groups submitted to physical exercise did not appear to develop lesions and presented a significantly lower parasite load independent of drug treatment. They also showed a positive delayed hypersensitivity response to a specific Leishmania antigen compared to control animals. The IFN-γ/IL-4 and IFN-γ/IL10 ratios in trained animals were clearly tilted to a Th1 response in lymph node cells. These data suggest that moderate intensity exercise is able to modulate the Th1 response that provides a protective effect against the development of leishmanial lesions
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