2,488 research outputs found

    Chitosan application in maize (Zea mays) to counteract the effects of abiotic stress at seedling level

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    Worldwide, the conditions of biotic and abiotic stresses adversely affect the potential production of maize. Drought or heat facilitate the infection with fungi such as Aspergillus flavus and Fusarium moniliforme, and consequently increase the production of mycotoxins. There are several strategies for managing the problem, but in the future, people will prefer the cleaner and cheaper technology. The use of elicitors for protection of corn can be considered a cheap and clean technology. Chitosan elicitor is a linear polysaccharide produced commercially by deacetylation of chitin. It has been reported that this elicitor induce phytoalexin accumulation in plant tissue. Application of chitosan to seeds in rice significantly increased rice yield. About this, there are no reports in corn. For this reason, the aim of this study was to determine the protective effect of chitosan in maize seedlings subjected to abiotic stresses. To this end, three treatments were tested (a negative control, a positive control, and a group coated with chitosan solution) under four abiotic stresses conditions since their germination stage: drought, moisture, acid pH and alkaline pH. During five weeks, the seedlings growth was evaluated by measuring their total length, the length of leaves, stems and the thickness of these and presence of fungi. Positive effect was observed in seeds treated with chitosan or stressed with acidic pH in dimensions of seedlings and there was no fungal growth.Key words: Abiotic stress, Zea mays, chitosan, pH, drought, humidit

    Fins da pena no Estado Democrático de Direito: ainda faz sentido defender o caráter preventivo da pena e a necessidade de ressocialização do condenado?

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    A função e a finalidade da pena nunca foram bem explicadas pelo Direito Penal, ora porque as discussões dogmáticas não são sequer verificadas na prática, ora porque a prática reconduz questionamentos que colocam em xeque o próprio sentido teórico-científico da imposição de pena ao condenado. Como este assunto nunca descansou no remansoso campo das questões penais pacificadas, o presente artigo visa contribuir de maneira positiva para o debate trazendo para o leitor o necessário confronto entre a teoria e a prática, buscando, ao fim, extrair de ambas o que ainda resta como verdadeira essência da pena estatal

    Reporting quality of social and psychological intervention trials: a systematic review of reporting guidelines and trial publications

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    Previous reviews show that reporting guidelines have improved the quality of trial reports in medicine, yet existing guidelines may not be fully suited for social and psychological intervention trials. OBJECTIVEDESIGN: We conducted a two-part study that reviewed (1) reporting guidelines for and (2) the reporting quality of social and psychological intervention trials

    Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation

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    FUNDING AND DISCLOSURE The research was funded by Wellcome Trust (WT098012) to LKH; and National Institute of Health (DK056731) and the Marilyn H. Vincent Foundation to MGM. The University of Michigan Transgenic Core facility is partially supported by the NIH-funded University of Michigan Center for Gastrointestinal Research (DK034933). The remaining authors declare no conflict of interest. ACKNOWLEDGMENTS We thank Dr Celine Cansell, Ms Raffaella Chianese and the staff of the Medical Research Facility for technical assistance. We thank Dr Vladimir Orduña for the scientific advice and technical assistance.Peer reviewedPublisher PD

    Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants

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    An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens

    Evidence for distinct coastal and offshore communities of bottlenose dolphins in the north east Atlantic.

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    Bottlenose dolphin stock structure in the northeast Atlantic remains poorly understood. However, fine scale photo-id data have shown that populations can comprise multiple overlapping social communities. These social communities form structural elements of bottlenose dolphin (Tursiops truncatus) [corrected] populations, reflecting specific ecological and behavioural adaptations to local habitats. We investigated the social structure of bottlenose dolphins in the waters of northwest Ireland and present evidence for distinct inshore and offshore social communities. Individuals of the inshore community had a coastal distribution restricted to waters within 3 km from shore. These animals exhibited a cohesive, fission-fusion social organisation, with repeated resightings within the research area, within a larger coastal home range. The offshore community comprised one or more distinct groups, found significantly further offshore (>4 km) than the inshore animals. In addition, dorsal fin scarring patterns differed significantly between inshore and offshore communities with individuals of the offshore community having more distinctly marked dorsal fins. Specifically, almost half of the individuals in the offshore community (48%) had characteristic stereotyped damage to the tip of the dorsal fin, rarely recorded in the inshore community (7%). We propose that this characteristic is likely due to interactions with pelagic fisheries. Social segregation and scarring differences found here indicate that the distinct communities are likely to be spatially and behaviourally segregated. Together with recent genetic evidence of distinct offshore and coastal population structures, this provides evidence for bottlenose dolphin inshore/offshore community differentiation in the northeast Atlantic. We recommend that social communities should be considered as fundamental units for the management and conservation of bottlenose dolphins and their habitat specialisations

    Reserve size, dispersal and population viability of wide ranging carnivores: the case of jaguars in Emas National Park, Brazil

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    Protected areas may be important refuges for large carnivores, but many are not large enough to sustain viable populations. Without sufficient dispersal between protected areas, large carnivore populations inside them are at risk of becoming genetically isolated and demographically vulnerable. In this study, we use the jaguar population in and around Emas National Park in the Brazilian Cerrado as a case study to evaluate the demographic sustainability of a large carnivore population within a small and potentially isolated protected area. We used camera trapping data and spatially explicit capture-recapture models to estimate density and corresponding population size of jaguars in Emas National Park. We then used a matrix-based age and sex structured stochastic population model to evaluate the demographic viability of jaguar populations across a range of population sizes, including those estimated for Emas. We detected 10 individual jaguars during our survey with a total of 74 detections. Our density estimation became unbiased using a buffer width of 30 km and produced a density of 0.17 jaguars per 100 km2. The estimated population sizes of 10 to 60 animals suffered extinction risks of 70-90% without net immigration. However, only a low number of immigrants were required to suppress extinction risk towards zero. Our density estimate for jaguars was lower than in previous studies, and our simulations suggested that this population may have a substantial extinction risk. Ensuring dispersal and connectivity outside of protected areas, through the implementation of habitat corridors, can greatly reduce this extinction risk, and we suggest that this scenario is potentially applicable to many other large carnivore populations

    Non-thermal emission processes in massive binaries

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    In this paper, I present a general discussion of several astrophysical processes likely to play a role in the production of non-thermal emission in massive stars, with emphasis on massive binaries. Even though the discussion will start in the radio domain where the non-thermal emission was first detected, the census of physical processes involved in the non-thermal emission from massive stars shows that many spectral domains are concerned, from the radio to the very high energies. First, the theoretical aspects of the non-thermal emission from early-type stars will be addressed. The main topics that will be discussed are respectively the physics of individual stellar winds and their interaction in binary systems, the acceleration of relativistic electrons, the magnetic field of massive stars, and finally the non-thermal emission processes relevant to the case of massive stars. Second, this general qualitative discussion will be followed by a more quantitative one, devoted to the most probable scenario where non-thermal radio emitters are massive binaries. I will show how several stellar, wind and orbital parameters can be combined in order to make some semi-quantitative predictions on the high-energy counterpart to the non-thermal emission detected in the radio domain. These theoretical considerations will be followed by a census of results obtained so far, and related to this topic... (see paper for full abstract)Comment: 47 pages, 5 postscript figures, accepted for publication in Astronomy and Astrophysics Review. Astronomy and Astrophysics Review, in pres
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