732 research outputs found
Stationary substrates facilitate bioinvasion in Paranaguá Bay in southern Brazil
Artificial substrates in and near ports and marinas commonly have many non-indigenous species and are the first stepping stone for the establishment of bioinvasors. Substrate movement influences fouling communities and so understanding of how species assemblages are related to specific substrate conditions is crucial as a management tool. Here we describe the species assemblage of the community after six months of development on granite plates in Paranaguá Bay. Species richness was similar in the two treatments, with 12 species on floating (constant depth) plates and 15 on stationary (variable depth) plates. However, species composition differed, with the community on floating plates being dominated by the native bivalve Mytella charruana (66.1 ± 5.5% cover) and that on stationary plates dominated by the barnacles Fistulobalanus citerosum (49.8 ± 3.5% cover) and the introduced Amphibalanus reticulatus (33.9 ± 3.7% cover). Other introduced species were Garveia franciscana, on one stationary plate, and Megabalanus coccopoma also on one stationary plate and not very abundant on half of the floating plates (< 2%). Thus, stationary plates were more susceptible to introduced species that may become very abundant, suggesting that this type of substrate should be a priority in management for bioinvasion control. We also hypothesize that the native bivalve M. charruana is the dominant competitor for space on floating substrates, thereby reducing the invasiveness of that type of substrate.Substratos artificiais em regiões de portos e marinas geralmente abrigam muitas espécies introduzidas e sua colonização constitui o primeiro passo no estabelecimento de bioinvasores. O grau de movimentação do substrato influencia a comunidade incrustante e o conhecimento da assembléia de espécies associada a cada situação é crucial como ferramenta de manejo. Neste trabalho, reportamos a estrutura de comunidades de seis meses desenvolvidas em substratos de granito na baía de Paranaguá. Foram encontradas 12 espécies na condição flutuante (profundidade constante) e 15 na condição fixa (profundidade variável), mas o número médio de espécies por placa não foi diferente nos tratamentos. A comunidade das placas flutuantes foi dominada pelo bivalve nativo Mytella charruana (66.1 ± 5.5% de cobertura), enquanto as placas fixas foram dominadas pelos cirripédios Fistulobalanus citerosum (49.8 ± 3.5%) e Amphibalanus reticulatus (33.9 ± 3.7%), este último introduzido na região. Outras espécies introduzidas encontradas foram Garveia franciscana, em apenas uma placa fixa, e Megabalanus coccopoma também em uma placa fixa e em metade das placas flutuantes, mas sempre com baixa cobertura (< 2%). Em conclusão, placas fixas foram mais suscetíveis às espécies introduzidas, uma delas ocorrendo em alta abundância, o que sugere que este tipo de substrato deveria ser priorizado em ações de controle e manejo de bioinvasão. Também hipotetizamos que o bivalve nativo M. charruana é o competidor dominante por espaço na condição flutuante, reduzindo a susceptibilidade deste substrato à bioinvasão
Nutrição de tithonia diversifolia e atributos do solo adubado com biofertilizante em sistema irrigado
The fertilization with biofertilizer associated with the use of irrigation favors nutrient uptake by plants and soil chemical properties; however, these effects are little studied in Tithonia diversifolia in semiarid regions. This study evaluated the effect of doses of bovine biofertilizer and irrigation on accumulation of nutrients in the leaves of Tithonia diversifolia plants and on soil chemical attributes. The study was carried out from December 3, 2014 to November 28, 2015, and arranged in a 2 x 5 factorial scheme, consisting of five doses of bovine biofertilizer (0, 40, 80, 120 and 160 m3 ha-1), combined with and without irrigation. The experiment was set in a randomized block design, using three replicates. Irrigation promoted increased accumulation of N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu and B in leaves of Tithonia diversifolia in the first cutting. However, the high bicarbonate concentration in the irrigation water and the occurrence of rainfall during the second crop increased the accumulation of Cu in the leaves of Tithonia diversifolia under rainfed condition, compared with irrigated plants. The increase in biofertilizer doses contributed to the increment of base saturation and the contents of organic matter, P and K in soil201110081013Associada ao uso de irrigação, a adubação com biofertilizante favorece a absorção de nutrientes pelas plantas e as propriedades químicas dos solos, porém tais efeitos são pouco estudados no cultivo de Tithonia diversifolia em regiões semiáridas. Avaliaram-se os efeitos de doses de biofertilizante bovino e da irrigação no acúmulo foliar de nutrientes em plantas de Tithonia diversifolia e nos atributos químicos do solo. O estudo foi conduzido entre 3 de dezembro de 2014 e 28 de novembro de 2015 e distribuído em esquema fatorial 5 x 2, consistindo de cinco doses de biofertilizante bovino (0, 40, 80, 120 e 160 m3 ha-1), combinado com e sem irrigação. O delineamento estatístico do experimento foi em blocos casualizados com três repetições. A irrigação promoveu aumento no acúmulo de N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu e B em folhas de Tithonia diversifolia no primeiro corte; entretanto, a alta concentração de bicarbonato na água de irrigação e a presença de chuvas durante o segundo cultivo aumentaram o acúmulo de Cu nas folhas de Tithonia diversifolia em sequeiro quando comparado às plantas irrigadas. O aumento das doses de biofertilizante contribuiu para o incremento da saturação por base e do teor de matéria orgânica, P e K no sol
Substrate type as a selective tool against colonization by non-native sessile invertebrates
Substratos de diferentes materiais, cores, texturas e orientação podem influenciar seletivamente no recrutamento de invertebrados sésseis e, assim, influenciar a comunidade resultante. Deste modo, o substrato pode funcionar como barreira contra o estabelecimento de espécies não nativas (NIS, na sigla em inglês). No sul do Brasil, o granito é a principal rocha formadora de costões rochosos naturais disponíveis para organismos incrustantes. Nesta investigação, nós testamos se o granito seleciona o recrutamento de espécies e se poderia, assim, impedir a colonização de espécies introduzidas ou criptogênicas já estabelecidas em substratos artificiais na região. Placas não polidas de granito e de polietileno foram submersas a cada mês em um píer de um iate clube na Baía de Paranaguá. Há uma comunidade já estabelecida sobre colunas de concreto e sobre flutuadores de fibra de vidro presentes no iate clube. Depois de um, dois e doze meses, as espécies presentes nas placas de diferentes materiais foram comparadas entre si e também com outros substratos. O granito foi colonizado por todas as sete espécies introduzidas encontradas na região, e por 18 das 26 espécies criptogênicas, sendo então ineficaz como barreira contra a colonização de NIS.Different substrates of varying composition, color, texture and orientation may selectively influence recruitment of sessile invertebrates and thereby influence the resultant community. Thus substrates may act as a barrier to the establishment of non-indigenous species (NIS). In southern Brazil, granite is the main rock forming natural rocky walls that are available for encrusting organisms. In this study we tested whether granite selectively influences recruitment and impedes colonization by introduced and cryptogenic species that are already established on artificial substrates within the region. Plates of rough cut granite and of polyethylene were made available each month under a pier at a yacht club in Paranaguá Bay. A community is already established on concrete columns and fiber glass floats on the piers. After one, two and twelve months, the faunal composition of the plates was compared between the two treatments and other artificial substrates. Granite was recruited by all the seven introduced species found in the Bay and by 18 of 26 cryptogenic species and therefore is ineffective as a barrier to NIS colonization
Nicotinic acid induces antinociceptive and anti-inflammatory effects in different experimental models
AbstractAlthough in vitro studies have shown that nicotinic acid inhibits some aspects of the inflammatory response, a reduced number of in vivo studies have investigated this activity. To the best of our knowledge, the effects induced by nicotinic acid in models of nociceptive and inflammatory pain are not known. Per os (p.o.) administration of nicotinic acid (250, 500 or 1000mg/kg, −1h) inhibited the first and the second phases of the nociceptive response induced by formalin in mice. Nicotinic acid (250 or 500mg/kg, −1 and 3h) also inhibited the mechanical allodynia induced by carrageenan in rats, a model of inflammatory pain. However, in a model of nociceptive pain, exposure of mice to a hot-plate, nicotinic acid was devoid of activity. In addition to inhibiting the nociceptive response in models of inflammatory pain, nicotinic acid (250 or 500mg/kg, p.o., −1 and 3h) inhibited paw edema induced by carrageenan in mice and rats. Picolinic acid (62.5 or 125mg/kg, p.o., −1h), a nicotinic acid isomer, inhibited both phases of the nociceptive response induced by formalin, but not paw edema induced by carrageenan in mice. The other nicotinic acid isomer, isonicotinic acid, was devoid of activity in these two models. In conclusion, our results represent the first demonstration of the activity of nicotinic acid in experimental models of nociceptive and inflammatory pain and also provide further support to its anti-inflammatory activity. It is unlikely that conversion to nicotinamide represents an important mechanism to explain the antinociceptive and anti-inflammatory activities of nicotinic acid. The demonstration of new activities of nicotinic acid, a drug that has already been approved for clinical use and presents a positive safety record, may contribute to raise the interest in conducting clinical trials to investigate its usefulness in the treatment of painful and inflammatory diseases
Conopídeos (Diptera: Conopidae) parasitando Centris (Heterocentris) analis (Fabricius) (Hymenoptera: Apidae, Centridini)
Parasites of adult bees are almost exclusively flies and the most important of them are conopids. This note registers for the first time the association of species of Physocephala (Diptera: Conopidae) with Centris (Heterocentris) analis (Fabricius). From 26 females and nine males of the host species found dead inside trap-nests on the campus of the University of São Paulo, Ribeirão Preto, Brazil, 35 parasitoids were obtained belonging to nine species of Physocephala. The data show that C. analis is a host to several conopid flies, and suggest that such parasitoids can play an important role in population control of this bee species.Parasitas de abelhas adultas são quase exclusivamente moscas e dentre os mais importantes estão os conopídeos. Nesta comunicação relata-se pela primeira vez a associação de espécies de Physocephala (Diptera: Conopidae) com Centris (Heterocentris) analis (Fabricius). De uma amostra de 26 fêmeas e nove machos da espécie hospedeira encontrados mortos em ninhos-armadilha vazios, no campus da Universidade de São Paulo, Ribeirão Preto, SP, emergiram 35 parasitóides pertencentes a nove espécies de Physocephala. Os dados mostram que C. analis é hospedeiro para várias espécies de conopídeos e sugerem que tais parasitóides podem desempenhar um papel importante na regulação populacional dessa espécie de abelha.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Targeting liver stage malaria with metformin
Copyright: © 2019, American Society for Clinical InvestigationDespite an unprecedented 2 decades of success, the combat against malaria - the mosquito-transmitted disease caused by Plasmodium parasites - is no longer progressing. Efforts toward eradication are threatened by the lack of an effective vaccine and a rise in antiparasite drug resistance. Alternative approaches are urgently needed. Repurposing of available, approved drugs with distinct modes of action are being considered as viable and immediate adjuncts to standard antimicrobial treatment. Such strategies may be well suited to the obligatory and clinically silent first phase of Plasmodium infection, where massive parasite replication occurs within hepatocytes in the liver. Here, we report that the widely used antidiabetic drug, metformin, impairs parasite liver stage development of both rodent-infecting Plasmodium berghei and human-infecting P. falciparum parasites. Prophylactic treatment with metformin curtails parasite intracellular growth in vitro. An additional effect was observed in mice with a decrease in the numbers of infected hepatocytes. Moreover, metformin provided in combination with conventional liver- or blood-acting antimalarial drugs further reduced the total burden of P. berghei infection and substantially lessened disease severity in mice. Together, our findings indicate that repurposing of metformin in a prophylactic regimen could be considered for malaria chemoprevention.This work was supported by Fundação para a Ciência e Tecnologia (Portugal) PTDC/SAU-MET/118199/2010 to LMS and European Research Council Proof of Concept Grant to MMM (ERC-2015-PoC-DL3–713691-REUSE4MALARIA).info:eu-repo/semantics/publishedVersio
Towards Lightweight Dynamic Adaptation : A Framework and its Evaluation
Many modern systems must run in continually changing contexts. For example, a computer vision system to detect vandalism in train stations must function during the day and at night. The software components for image acquisition and people detection used during daytime may not be the same as those used at night. The system must adapt by replacing running components such as image acquisition from color to infra-red. This adaptation involves context detection, decision on change in components, followed by seamless execution of a new configuration of components. All this must occur at runtime while minimizing the impact of dynamic change on continuity and loss in performance. We present Girgit, a lightweight Python-based framework for building dynamic adaptive software systems. We evaluate it by building a dynamically adaptive vision system followed by performing rigorous experiments to determine its continuity and performance.Sociedad Argentina de Informática e Investigación Operativ
ENERGY COST DURING WALKING AND RUNNING A SAME DISTANCE IS ASSOCIATED WITH VERTICAL OSCILLATION ON GRAVITY CENTER.
The purpose of this study was to evaluate which factors are involved in energetic cost of running and walking a same distance (2,000 meters). Eight healthy men were submitted
to walking (5.5km/h) and running (11Km/h) tests, when oxygen consumption, for energy expenditure of exercise, was monitored, and images of volunteers were recorded for
vertical oscillation of gravity center. Both, total oxygen consumption and estimated energetic cost were significantly higher during the running test (
PARQUES NACIONAIS BRASILEIROS: PROBLEMAS FUNDIÁRIOS E ALTERNATIVAS PARA A SUA RESOLUÇÃO
O texto faz um diagnóstico da situação fundiária dos parques nacionais brasileiros atualmente existentes.Argumenta que a herança cultural e política brasileira, o histórico dos órgãos que administraram osparques nacionais e as complexidades da questão fundiária são fatores determinantes dos entraves aoprocesso de regularização fundiária dessas unidades de conservação (UCs). O texto sustenta que a carênciade recursos financeiros para indenizações de terras a serem desapropriadas não é o maior entrave paraa resolução da questão. Propõe-se, além disso, diversos instrumentos legais e administrativos alternativosque podem ser acionados para regularizar ou incorporar terras aos parques nacionais e dar mais efetividadeà política de conservação da biodiversidade no Brasil. Por fim, conclui-se que a conservação dabiodiversidade vai muito além da criação de unidades de conservação de qualquer modalidade, sendonecessário que diferentes setores do poder público e da sociedade civil invistam também em ações defiscalização, formação de corredores ecológicos entre UCs de proteção integral e de uso sustentável, educaçãoambiental e implantação de instrumentos econômicos de gestão ambiental que induzam os proprietáriosparticulares de terras a adotarem práticas compatíveis com a conservação da natureza
Effects induced by Apis mellifera venom and its components in experimental models of nociceptive and inflammatory pain
AbstractThe effects induced by Apis mellifera venom (AMV), melittin-free AMV, fraction with molecular mass < 10 kDa (F<10) or melittin in nociceptive and inflammatory pain models in mice were investigated. Subcutaneous administration of AMV (2, 4 or 6 mg/kg) or melittin-free AMV (1, 2 or 4 mg/kg) into the dorsum of mice inhibited both phases of formaldehyde-induced nociception. However, F<10 (2, 4 or 6 mg/kg) or melittin (2 or 3 mg/kg) inhibited only the second phase. AMV (4 or 6 mg/kg), but not F<10, melittin-free AMV or melittin, induced antinociception in the hot-plate model. Paw injection of AMV (0.05 or 0.10 mg), F<10 (0.05 or 0.1 mg) or melittin (0.025 or 0.050 mg) induced a nociceptive response. In spite of inducing nociception after paw injection, scorpion (Tityus serrulatus) or snake (Bothrops jararaca) venom injected into the dorsum of mice did not inhibit formaldehyde-induced nociception. In addition, AMV (6 mg/kg), but not F<10 (6 mg/kg) or melittin (3 mg/kg), inhibited formaldehyde paw oedema. Concluding, AMV, F<10 and melittin induce two contrasting effects: nociception and antinociception. AMV antinociception involves the action of different components and does not result from non-specific activation of endogenous antinociceptive mechanisms activated by exposure to noxious stimuli
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