416 research outputs found

    Steps to build a DIY low-cost fixed-wing drone for biodiversity conservation

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    Despite the proved usefulness of drones in biodiversity studies, acquisition costs and difficulties in operating, maintaining and repairing these systems constrain their integration in conservation projects, particularly for low-income countries. Here we present the steps necessary to build a low-cost fixed-wing drone for environmental applications in large areas, along with instructions to increase the reliability of the system and testing its performance. Inspired by DIY (Do It Yourself) and open source models, this work prioritizes simplicity and accounts for cost-benefit for the researcher. The DIY fixed-wing drone developed has electric propulsion, can perform pre-programmed flight, can carry up to 500 g payload capacity with 65 minutes flight duration and flies at a maximum distance of 20 km. It is equipped with a RGB (Red, Green and Blue) sensor capable of obtaining 2.8 cm per pixel Ground Sample Distance (GSD) resolution at a constant altitude of 100 m above ground level (AGL). The total cost was $995 which is substantially less than the average value of similar commercial drones used in biodiversity studies. We performed 12 flight tests in auto mode using the developed model in protected areas in Brazil, obtaining RGB images that allowed us to identify deforestation spots smaller than 5 m2 and medium-sized animals. Building DIY drones requires some technical knowledge and demands more time than buying a commercial ready-to-fly system, but as proved here, it can be less expensive, which is often crucial in conservation project

    Noninvasive Technologies for Primate Conservation in the 21st Century

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    Observing and quantifying primate behavior in the wild is challenging. Human presence affects primate behavior and habituation of new, especially terrestrial, individuals is a time-intensive process that carries with it ethical and health concerns, especially during the recent pandemic when primates are at even greater risk than usual. As a result, wildlife researchers, including primatologists, have increasingly turned to new technologies to answer questions and provide important data related to primate conservation. Tools and methods should be chosen carefully to maximize and improve the data that will be used to answer the research questions. We review here the role of four indirect methods—camera traps, acoustic monitoring, drones, and portable field labs—and improvements in machine learning that offer rapid, reliable means of combing through large datasets that these methods generate. We describe key applications and limitations of each tool in primate conservation, and where we anticipate primate conservation technology moving forward in the coming years

    Nested sampling for materials: the case of hard spheres

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    The recently introduced nested sampling algorithm allows the direct and efficient calculation of the partition function of atomistic systems. We demonstrate its applicability to condensed phase systems with periodic boundary conditions by studying the three dimensional hard sphere model. Having obtained the partition function, we show how easy it is to calculate the compressibility and the free energy as functions of the packing fraction and local order, verifying that the transition to crystallinity has a very small barrier, and that the entropic contribution of jammed states to the free energy is negligible for packing fractions above the phase transition. We quantify the previously proposed schematic phase diagram and estimate the extent of the region of jammed states. We find that within our samples, the maximally random jammed configuration is surprisingly disordered

    Spatiotemporal variability of the coastal circulation in the northern Gulf of Cadiz from Copernicus Sentinel-3A satellite radar altimetry measurements

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    This study presents a generalised characterisation of the surface circulation over the northern shelf of the Gulf of Cadiz, based on 4 years of high-resolution satellite altimetry data from Sentinel-3A and wind model data. The altimetry-based surface zonal currents, adjusted for bottom-drag and wind effects, are compared with a generic CMEMS product and validated against in-situ ADCP measurements. The proposed altimetry product demonstrates superior performance than the CMEMS product, accurately reflecting surface circulation direction compared to in-situ measurements (r = 0.77, RMSE = 0.10 m/s, bias = 0.01 m/s). The use of the bottom-drag and wind-corrected/uncorrected altimetry product for spatiotemporal analysis of the shelf circulation revealed the distinct contributions of wind-driven and geostrophic components in different basin sectors. The results show that over the western basin, positive (eastward) surface currents were predominantly driven by westerly winds, while only occasionally, westward flows coincided with easterly winds, suggesting a higher control of the geostrophic component over the westward flows. In contrast, over the eastern basin, both eastward and westward flows were found to be primarily driven by favourable winds. Additionally, the analysis of Absolute Dynamic Topography (ADT) values along the whole basin showed the presence of ADT gradients both along-shore and cross-shore over the shelf, contributing to geostrophic flows. Finally, the seasonal analysis showed that eastward circulation tends to dominate during the spring and summer months, related to the upwelling season in the Gulf of Cadiz and associated westerly winds. Westward flows prevail during the winter months, related to easterly winds and the rebalancing of the along-shore sea level gradient during relaxed upwelling conditions. The findings demonstrate a significant improvement in the use of satellite altimetry data to study complex oceanographic dynamics in coastal areas, where both spatial and temporal variability are high. Moreover, the similarity of our results to those obtained from in-situ systems supports the use of altimetry data and publicly available wind models to support oceanographic studies in remote or resource-limited areas

    Additive Role of Immune System Infiltration and Angiogenesis in Uveal Melanoma Progression

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    Uveal melanoma (UM) is a malignant tumor that arises in the melanocytes of the uveal tract. It is the most frequent eye cancer, and despite new therapeutic approaches, prognosis is still poor, with up to 50% of patients developing metastasis with no efficient treatment options available. In contrast to cutaneous melanoma, UM is considered an "immune-cold" tumor due to the low mutational burden and the unique immunosuppressive microenvironment. To gain insight into the role of the UM microenvironment in regard to prognosis and metastatic progression, we have performed a pool analysis characterizing the UM microenvironment by using a bioinformatic approach. A variety of scores based on gene expression measuring stromal infiltration were calculated and used to assess association with prognosis. As a result, the highest immune and stromal scores were associated with poor prognosis. Specifically, stromal cells (fibroblasts and endothelial cells), T cells CD8+, natural killer (NK) cells, and macrophages M1 and M2 infiltration were associated with poor prognosis. Contrary to other tumors, lymphocytic infiltration is related to poor prognosis. Only B cells were associated with more favorable prognosis. UM samples scoring high in both angiogenesis (Angio) and antigen presentation (AP) pathways showed a poor prognosis suggesting an additive role of both functions. Almost all these tumors exhibited a chromosome 3 monosomy. Finally, an enrichment analysis showed that tumors classified as high Angio-high AP also activated metabolic pathways such as glycolysis or PI3K-AKT-MTOR. In summary, our pool analysis identified a cluster of samples with angiogenic and inflammatory phenotypes exhibiting poor prognosis and metabolic activation. Our analysis showed robust results replicated in a pool analysis merging different datasets from different analytic platforms

    Beneficial effects of manually assisted chiropractic adjusting instrument in a rabbit model of osteoarthritis.

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    Osteoarthritis (OA) is a degenerative disease characterized by injury of all joint tissues. Our previous study showed that in experimental osteoporosis, chiropractic manipulation (CM) exerts protective effects on bone. We here assessed whether CM might ameliorate OA by improving subchondral bone sclerosis, cartilage integrity and synovitis. Male New-Zealand rabbits underwent knee surgery to induce OA by anterior cruciate ligament injury. CM was performed using the chiropractic instrument ActivatorV 3 times/week for 8 weeks as follows: force 2 setting was applied to the tibial tubercle of the rabbit right hind limb (TM-OA), whereas the corresponding left hind limb received a false manipulation (FM-OA) consisting of ActivatorV firing in the air and slightly touching the tibial tubercle. After sacrifice, subchondral bone integrity was assessed in the tibiae by microCT and histology. Cartilage damage and synovitis were estimated by Mankin's and Krenn's scores, respectively, and histological techniques. Bone mineral density and content in both cortical and trabecular compartments of subchondral bone decreased in OA rabbits compared to controls, but partially reversed in the TM-OA group. Trabecular bone parameters in the latter group also showed a significant improvement compared to FM-OA group. Moreover RANKL, OPG, ALP and TRAP protein expression in subchondral bone significantly decreased in TM-OA rabbits with respect to FM-OA group. CM was associated with lower Mankin's and Krenn's scores and macrophage infiltrate together with a decreased protein expression of pro-inflammatory, fibrotic and angiogenic factors, in TM-OA rabbits with respect to FM-OA. Our results suggest that CM may mitigate OA progression by improving subchondral bone as well as cartilage and synovial membrane status.AODM was supported by grants from the Spanish Chiropractic Association (AEQ). AM was supported by grants from Spanish Ministry of Economy and Competitiveness and Carlos III Institute of Health (CP15/00053 and PI16/00991). We thank Dr. Carlos Guillén-Viejo (School of Pharmacy, Universidad Complutense de Madrid) for his help in advising in molecular biology methods. The authors are also grateful to Mark S. Davis for his assistance with editing and proofreading the article.S

    Production and characterization of monoclonal antibodies specific to gilthead seabream Sparus auratus Linnaeus, 1758 phagocytes

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    In the present study; we produced and characterised three monoclonal antibodies that react with phagocytes of the gilthead seabream Sparus auratus Linnaeus; 1758. Their usefulness in basic and applied research is discussed.En el presente estudio se han obtenido y caracterizado tres anticuerpos monoclonales que reconocen específicamente los fagocitos de dorada, Sparus auratus Linnaeus, 1758. Se discute su utilidad en la investigación básica y su aplicación en la piscicultura.Instituto Español de Oceanografí

    Use of recombinant cytokines to prevent infectious diseases in aquaculture: Reality or fiction?

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    The present paper reports on a study in which we cloned the IL-1βgene of the gilthead seabream Sparus auratus Linnaeus, 1758, and produced the corresponding recombinant protein, in order to assess its usefulness as an immunostimulant and vaccine adjuvant in aquaculture.En el presente estudio se ha clonado el gen de la IL-1β de dorada Sparus auratus Linnaeus, 1758, y se ha producido la correspondiente proteína recombinante para evaluar su uso como inmunoestimulante y adyuvante en peces objeto de cultivo industrial.Instituto Español de Oceanografí
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