1,740 research outputs found

    New Records Of Aparasphenodon Bokermanni (pombal, 1993) From Santa Catarina, Southern Brazil, And Extension Of Genus Range (anura: Hylidae)

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    Aparasphenodon bokermanni is a poorly known casque-headed tree frog found in São Paulo and Santa Catarina, southern Brazil. Here we provide two new records, one from Joinville, northeastern Santa Catarina, and the first record from Santa Catarina Island, Brazil, which extends to the south the range of the genus by approximately 150 km. © 2016 Check List and Authors.12

    A semi-supervised Genetic Programming method for dealing with noisy labels and hidden overfitting

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    Silva, S., Vanneschi, L., Cabral, A. I. R., & Vasconcelos, M. J. (2018). A semi-supervised Genetic Programming method for dealing with noisy labels and hidden overfitting. Swarm and Evolutionary Computation, 39(April), 323-338. DOI: 10.1016/j.swevo.2017.11.003Data gathered in the real world normally contains noise, either stemming from inaccurate experimental measurements or introduced by human errors. Our work deals with classification data where the attribute values were accurately measured, but the categories may have been mislabeled by the human in several sample points, resulting in unreliable training data. Genetic Programming (GP) compares favorably with the Classification and Regression Trees (CART) method, but it is still highly affected by these errors. Despite consistently achieving high accuracy in both training and test sets, many classification errors are found in a later validation phase, revealing a previously hidden overfitting to the erroneous data. Furthermore, the evolved models frequently output raw values that are far from the expected range. To improve the behavior of the evolved models, we extend the original training set with additional sample points where the class label is unknown, and devise a simple way for GP to use this additional information and learn in a semi-supervised manner. The results are surprisingly good. In the presence of the exact same mislabeling errors, the additional unlabeled data allowed GP to evolve models that achieved high accuracy also in the validation phase. This is a brand new approach to semi-supervised learning that opens an array of possibilities for making the most of the abundance of unlabeled data available today, in a simple and inexpensive way.authorsversionpublishe

    Land use dynamics under the Bolsa Floresta Program: a case study of the Uatumã Sustainable Development Reserve (Amazonas, Brazil)

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    Original ArticleThe effectiveness of a program of payment for environmental services (PES) in the Brazilian Amazon was analyzed through an accurate mapping of deforested areas. The Bolsa Floresta Program (BFP) in Amazonas state (Brazil) was chosen as an example of a PES program that aims to compensate farmers for their commitment to zero deforestation of primary forests while opening swiddens only in secondary vegetation areas. However, the official measurement of opened swiddens is not effective since only deforested areas larger than 6.25 ha are mapped, whereas most areas opened for cassava crops are approximately 1 ha in size. The effectiveness of the BFP was evaluated in the Uatumã Sustainable Development Reserve (SDR). We tested a methodology for mapping areas from 0.45 ha upwards that have been opened for cassava swiddens. The years 2006 (before the implementation of the BFP), 2011, 2015 and 2019 were analyzed. The results indicated that 88% of the areas opened for swiddens were between 0.45 and 6.25 ha in size. After the implantation of the BFP, the cumulative total deforested area decreased, and there was a reduction in deforested areas in primary forests. An intensification of swidden cultivation was also observed, which could cause a decline in productivity. The monitoring by land-use zoning showed that the majority of opened areas were located in intensive use zones, following the rules of the SDR management plan. The results show the efforts of local families to fulfill the BFP rulesinfo:eu-repo/semantics/publishedVersio

    A Contingent Valuation Study Of Buriti (mauritia Flexuosa L.f.) In The Main Region Of Production In Brazil: Is Environmental Conservation A Collective Responsibility?

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The immature leaves of the buriti palm (Mauritia flexuosa) are widely harvested in the municipality of Barreirinhas, Maranhão, for the production of handicrafts, which are sold to locals and tourists. The increasing demand for these artisanal goods is stimulating the emergence of an informal market for immature buriti leaves, leading to an intensification of their extraction and resulting in negative effects on local buriti palm populations and the ecosystem. Thus, the objective of the present study was to assess the environmental value of the buriti palm tree based on the maximum willingness to pay (WTP) for its conservation, using the contingent valuation method. Among the respondents, 99.74% reported that the palm species should be protected and the majority of them (65.75%) agreed to pay for its conservation (annual WTP R$ 179.49 ± 222.05). Multivariate analysis revealed that the WTP was not influenced by the socio-economic profile of the respondents. The main reasons for non-WTP are related to dissatisfaction with the government and the belief that financial contributions would not solve problems of environmental damage. Overall, the evaluated population believes that environmental conservation is not an obligation of the government or that of the population, but is a collective responsibility. © 2016, Sociedade Botanica do Brasil. All rights reserved.304532539CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorMOE, Ministry of EducationCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Differential gene expression and immunolocalization of platelet-derived growth factors and their receptors in caprine ovaries

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    AbstractThis study evaluated the messenger RNA (mRNA) expression and immunolocalization of all members of the platelet-derived growth factor (PDGF) family in caprine ovaries by quantitative PCR and immunohistochemistry, respectively. Detectable levels of PDGF-A mRNA were not observed in primordial follicles. Higher levels of PDGF-B mRNA were observed in primary follicles than in primordial follicles (P < 0.05). PDGF-D mRNA levels were higher in secondary follicles than in the other preantral follicle categories (P < 0.05). PDGF-B mRNA expression was higher than PDGF-C mRNA expression in primary follicles (P < 0.05). In antral follicles, PDGF-A mRNA expression was higher in cumulus-oocyte complexes (COCs) from small antral follicles than in those from large antral follicles and their respective granulosa/theca (GT) cells (P < 0.05). Furthermore, in COCs from small and large antral follicles, PDGF-A mRNA expression was higher than that of the other PDGF isoforms (P < 0.05). The mRNA levels of PDGF-B and PDGF-D and PDGFR-α and PDGFR-β were higher in GT cells from large antral follicles than in GT cells from small antral follicles and in their respective COCs (P < 0.05). In COCs and GT cells from small antral follicles, the mRNA levels of PDGFR-α were higher than those of PDGFR-β (P < 0.05). All proteins were observed in the cytoplasm of oocytes from all follicular categories. In granulosa cells, all PDGFs and PDGFR-β were detected from starting at the secondary stage, and in theca cells, all proteins, except PDGF-C, were detected starting at the antral stage. In conclusion, PDGF and its receptors are differentially expressed in the oocytes and ovarian cells according to the stage of follicular development, suggesting their role in the regulation of folliculogenesis in goats

    An erbium(III)-based NIR emitter with a highly conjugated ß-diketonate for blue-region sensitization

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    The sensitization of lanthanide complexes in the visible region is of particular interest for practical applications such as labeling, biological analysis and optoelectronics. A visible-light sensitized Er3+complex based on the use of a highly conjugated ß-diketonate (1, 3-di(2-naphthyl)-1, 3-propanedione, Hdnm) and 5-nitro-1, 10-phenanthroline (5NO2phen) as an ancillary ligand, [Er(dnm)3(5NO2phen)], has been synthesized, fully characterized and its photophysical properties have been investigated. Suitably expanded p-conjugation in the complex molecule makes the excitation window red-shifted to the visible region (up to 550 nm). Efficient energy transfer by antenna effect results in 1.53 µm emission from the Er3+ion

    Alien reptiles on Mediterranean Islands : A model for invasion biogeography

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    Aim: The Mediterranean basin has a long history of interactions between humans and biota, with multiple ancient and recent introductions of alien species. Such a multitude of introductions makes it difficult to distinguish between alien and native species but provides an excellent opportunity to investigate factors related to introductions and long-term persistence of alien species. In this study, we combined genetic and distribution data to identify the factors promoting the presence of alien reptiles on islands, considering human-related, geographic and species features. Furthermore, we assessed whether the use of genetic evidence to identify alien species improves inference of the factors determining their distribution. Location: Mediterranean islands. Methods: We combined genetic data and distribution databases to obtain information on biological traits and on the native/alien status of reptiles on &gt;900 Mediterranean islands, and we gathered data on geographic and human features of islands. We then used spatially explicit generalized additive mixed models to identify the factors associated with the establishment of alien reptiles. Results: Alien reptile populations are more frequent on islands far from the native range and with large human population. Alien populations of reptiles that are able to feed on plants are particularly frequent. Traditional data sources underestimate the frequency of alien reptiles on Mediterranean islands, and using genetic evidence to assess the status of populations provided a more complete picture of the factors associated with the presence of alien populations. Main conclusions: Humans are key drivers of the distribution of alien reptiles on Mediterranean islands, but the distributions are determined by a complex interplay between human activities, geographic factors and species features. Genetic data are essential for obtaining reliable biogeographic assessments of invasive species, particularly in systems with a long history of human influence
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