1,122 research outputs found

    When the blanket is too short: Potential negative impacts of expanding indigenous land over a national park in a high priority area for conservation

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    Land claims by indigenous peoples can cause changes in established protected areas. The consequences of such changes for biodiversity conservation will be context-dependent and influenced by characteristics of the indigenous population as well as the protected area affected. In the Cerrado-Caatinga ecotone of Brazil, there is an ongoing legal process to expand the Xacriabá Indigenous Land. The Xacriabás are claiming an additional 433 km2, which overlaps with one third of Cavernas do Peruaçu National Park. I used local scale data and occupancy modelling to show that expanding this indigenous land at the expense of the already reduced area under strict protection in the Cerrado and Caatinga is likely to decrease the national park's conservation effectiveness. My analysis suggests that intensification of human presence in the overlapping area between the two land designations will result in loss of native vegetation, increase in the number of fires and might have a negative impact on populations of more sensitive species

    Amphibian species composition and priorities for regional conservation at the Espinhaço mosaic, Southeastern Brazil

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    The southern portion of the Espinhaço Range in Brazil is recognized worldwide as a priority area for biodiversity conservation, and it contains a high number of endemic anuran species. We conducted field surveys and compiled published data on amphibian community composition from seven sites within Espinhaço Mosaic (EM; 910,000 ha) to explore the contribution of this area to amphibian species richness in the southern Espinhaço Range. We aimed to describe local and regional community composition and to identify priorities for future amphibian surveys and inventories in the study area. We consider the EM a species-rich area sheltering 73 anuran species, which represents 36.5% of the amphibians known for the state of Minas Gerais, 57.5% of those in the Cerrado biome, and almost 70% of the species in the Espinhaço Range. Unequal sampling effort is a major concern in the study area, and species richness in under-sampled sites might increase as new assessments are conducted. Therefore, sites for which no data are available should be prioritized for species inventories. Although an increase in sampling effort is likely to reduce the proportion of exclusive species (i.e., species known to occur in only one of the seven investigated sites), we conclude that the levels of endemicity indicate a high number of narrowly distributed (micro-endemic) species. We believe anuran community composition and similarities in composition among the sites investigated are influenced by the gradient between the Cerrado and Atlantic Rainforest biomes, which deserves further investigation

    Feeding ecology and spraint deposition sites of the Neotropical otter (Lontra longicaudis) at Cavernas do Peruaçu National Park, Brazil

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    Knowledge on the feeding ecology and habitat use of a species is of essential value for effective conservation. We describe the diet and spraints deposition sites for the Neotropical otter (Lontra longicaudis) at Cavernas do Peruaçu National Park, in south eastern Brazil. We collected spraints and recorded characteristics of the deposition sites from 2007-2010. We described otter diet as the number of faeces in which a given taxon was found and the frequency of occurrence of each taxon. We collected 57 spraints and identified 92 food items from nine different taxa, all from animal origin. Fish was the most frequent taxon, found in 98.3% of our samples, followed by arthropods (22.8%) and mammals (10.5%). We recorded 112 spraint deposition sites, most of them located in caves (80%) and < 10 m from the water (93.4%). In our study area the Neotropical otter relies heavily on fish, and we believe that the behaviour of some fish species makes them more vulnerable to predation. Habitat use by otters has important management implications for the national park, as caves are the main tourist attraction and some tourist tracks are located next to the river. Although a well-implemented management action might seem enough to avoid negative impacts of tourism, we believe that monitoring the Neotropical otter population in our study area is of major conservation concern to evaluate the impacts of this activity

    Strict protected areas are essential for the conservation of larger and threatened mammals in a priority region of the Brazilian Cerrado

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    ssessing protected area (PA) effectiveness is key to ensure the objectives of habitat protection are being achieved. There is strong evidence that legal protection reduces loss of natural vegetation, but biodiversity loss can still happen without significant changes in vegetation cover. Here we use data from a specifically designed camera trap survey to conduct a counterfactual assessment of PA effectiveness at safeguarding local biodiversity in the Brazilian Cerrado. We surveyed the mammal community in 517 locations at the Sertão Veredas-Peruaçu mosaic, distributed across five strict PAs (264 survey sites in five arrays) and two multiple-use PAs with low management levels (253 survey sites in four arrays). We adopted a multi-species occupancy framework to analyse our dataset while also controlling for confounding factors not directly related to protection. Of the 21 species assessed, nine had higher occupancy in strict PAs, one had higher occupancy in multiple-use PAs, and ten did not respond to protection level. Site species richness was nearly twice as large in areas under stricter protection, with even greater differences for species richness of globally threatened and larger mammals (>15 kg). Overall we demonstrated that the strict PAs surveyed support higher mammal diversity than similar areas under less restrictive management, with a particular strong effect on larger and threatened species. Given that strict PAs cover only 3% of the Cerrado, our results suggest that expanding the area under strict protection is likely to benefit iconic species of the Brazilian savanna, such as the maned wolf and giant anteater

    Downscaling the Gap: Protected Areas, Scientific Knowledge and the Conservation of Amphibian Species in Minas Gerais, Southeastern Brazil

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    Protected areas (PAs) cover a small proportion of the Earth's surface and most species are not covered by the current network. Amphibians are the least represented group in PAs around the world and expanding the network is still the major recommendation for species conservation. We evaluated the effectiveness of PAs in safeguarding endemic amphibians in the Cerrado biome of Minas Gerais state, southeastern Brazil. We conducted a gap analysis to highlight site-based conservation actions for target species within study site. We extracted occurrence points from the national database and calculated the intersection between the minimum convex polygon and natural vegetation remnants for each species. For each target species, we calculated the percentage of the range covered by PAs and assessed the scientific knowledge based on academic publications between 1950–2015. We recorded 206 amphibians in Minas Gerais, of which 127 occur in the Cerrado. We identified 24 target species and concluded that 80% are insufficiently protected by the current PA network. A quarter of the species have zero coverage and most species have < 30% of their range legally protected. In southwestern Minas Gerais, we recommend habitat restoration and connectivity to provide additional habitat to target species. In western Minas Gerais, the creation of PA seems to be the best solution. The distribution of target species is concentrated in the Espinhaço Mountain Range, where we recommend the establishment of biodiversity corridors. We examined 246 publications, most of which focus on taxonomy. Few species have sufficient information to have their conservation status re-assessed, with only 26.8% of publications containing specific information on conservation. Scientific knowledge must be improved for all research areas, especially species distributions and ecology, to support evidence-based conservation and management actions

    Inter-Cohort Validation of SuStaIn Model for Alzheimer's Disease

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    Alzheimer's disease (AD) is a neurodegenerative disorder which spans several years from preclinical manifestations to dementia. In recent years, interest in the application of machine learning (ML) algorithms to personalized medicine has grown considerably, and a major challenge that such models face is the transferability from the research settings to clinical practice. The objective of this work was to demonstrate the transferability of the Subtype and Stage Inference (SuStaIn) model from well-characterized research data set, employed as training set, to independent less-structured and heterogeneous test sets representative of the clinical setting. The training set was composed of MRI data of 1043 subjects from the Alzheimer's disease Neuroimaging Initiative (ADNI), and the test set was composed of data from 767 subjects from OASIS, Pharma-Cog, and ViTA clinical datasets. Both sets included subjects covering the entire spectrum of AD, and for both sets volumes of relevant brain regions were derived from T1-3D MRI scans processed with Freesurfer v5.3 cross-sectional stream. In order to assess the predictive value of the model, subpopulations of subjects with stable mild cognitive impairment (MCI) and MCIs that progressed to AD dementia (pMCI) were identified in both sets. SuStaIn identified three disease subtypes, of which the most prevalent corresponded to the typical atrophy pattern of AD. The other SuStaIn subtypes exhibited similarities with the previously defined hippocampal sparing and limbic predominant atrophy patterns of AD. Subject subtyping proved to be consistent in time for all cohorts and the staging provided by the model was correlated with cognitive performance. Classification of subjects on the basis of a combination of SuStaIn subtype and stage, mini mental state examination and amyloid-β1-42 cerebrospinal fluid concentration was proven to predict conversion from MCI to AD dementia on par with other novel statistical algorithms, with ROC curves that were not statistically different for the training and test sets and with area under curve respectively equal to 0.77 and 0.76. This study proves the transferability of a SuStaIn model for AD from research data to less-structured clinical cohorts, and indicates transferability to the clinical setting

    Partitioning optimization of proteins from Zea mays malt in ATPS PEG 6000/CaCl2

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    This work aimed to establish the relationship between the compositions and pH of ATPS PEG 6000/CaCl2 and the proteins partition from maize malt and also to simplify the process optimization in ATPS for a statistical model, established by response surface methodology (RSM). Results showed that these were no influence of pH on the phase diagrams and on the composition of tie line length of PEG 6000/CaCl2 ATPS. SRM analyses showed that elevated pH and larger tie line length were the best conditions for recovering of maize malt proteins. The maximum partition coefficient by PEG 6000/CaCl2 ATPS was about 4.2 and was achieved in ATPS in a single purification step. The theoretical maximum partition coefficient was between 4.1-4.3. The process was very suitable for continuous aqueous two phase purification due to the stability of proteins (e.g. alpha and beta-amylases) and could increase their content into middle.50355756

    Assessing the conservation value of secondary savanna for large mammals in the Brazilian Cerrado

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    Debate about the conservation value of secondary habitats has tended to focus on tropical forests, increasingly recognizing the role of secondary forests for biodiversity conservation. However, there remains a lack of information about the conservation value of secondary savannas. Here, we conducted a camera trap survey to assess the effect of secondary vegetation on large mammals in a Brazilian Cerrado protected area, using a single-season occupancy framework to investigate the response of individual species (species-level models) and of all species combined (community-level models). In addition, we investigated the cost effectiveness of different sampling designs to monitor globally threatened species in the study area. At the community level, savanna that regenerated from eucalyptus plantation had similar occupancy estimate as old growth areas. At the species level, none of the ten species individually assessed seemed to respond to succession stage, with greater support for the effect of other covariates on occupancy, such as distance from water and vegetation physiognomy. These results demonstrate that secondary vegetation does not appear to negatively impact large mammals in the study area and suggest that, given a favorable context, Cerrado mammals can recolonize and use secondary savannas that regenerated from clearcut. However, our study area should be considered a best-case scenario, as it retained key ecological attributes of high-value secondary habitats. Our simulations showed that a sampling design with 60 camera trap sites surveyed during nine occasions is appropriate to monitor most globally threatened species in the study area, and could be a useful starting point for new monitoring initiatives in other Cerrado areas

    Case study on the efficacy of a lanthanum-enriched clay (Phoslock®) in controlling eutrophication in Lake Het Groene Eiland (The Netherlands)

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    Lake Het Groene Eiland was created in the beginning of 2008 by construction of dikes for isolating it from the surrounding 220-ha water body. This so-called claustrum of 5 ha was treated using lanthanum-modified clay (Phoslock®) to control eutrophication and mitigate cyanobacterial nuisance. Cyanobacteria chlorophyll-a were significantly lower in the claustrum than those in the reference water body, where a massive bloom developed in summer, 2008. However, PO4-P and TP did not statistically differ in these two waters. TN and NO3-N were significantly lower in the claustrum, where dense submerged macrophytes beds developed. Lanthanum concentrations were elevated after the applications of the modified clay in the claustrum, but filterable lanthanum dropped rapidly below the Dutch standard of 10.1 μg l−1. During winter, dozens of Canada geese resided at the claustrum. Geese droppings contained an average of 2 mg PO4-P g−1 dry weight and 12 mg NH3-N g−1 dry weight and might present a growing source of nutrients to the water. Constructing the claustrum enabled unrestricted bathing in subsequent three summers, as no swimming bans had to be issued due to cyanobacteria blooms. However, the role of the modified clay in this positive outcome remains unclear, and longevity of the measures questionable.
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