336 research outputs found

    Drones: una nueva tecnología para el estudio y monitoreo de fauna y hábitats.

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    The study and management of wildlife requires constant monitoring of the state of the populations and their habitats. This information is necessary to detect possible threats and to carry out effectively the management and conservation work. In the last 15 years the incorporation of a new tool of aerial monitoring of wildlife, colloquially named “drones”, has been seen, and in this study a brief description of these and their application in wildlife monitoring is made. The purpose is to present the advantages but also alert about their possible limitation

    Numerical solution of the viscous flow past a cylinder with a non-global yet spectrally convergent meshless collocation method

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    Proceeding of: 11th International Conference on Spectral and High-Order Methods (ICOSAHOM'16), June 27-July 1, 2016, Rio de Janeiro, Brazil.The flow of a viscous fluid past a cylinder is a classical problem in fluid-structure interaction and a benchmark for numerical methods in computational fluid dynamics. We solve it with the recently introduced radial basis function-based partition of unity method (RBF-PUM), which is a spectrally convergent collocation meshless scheme well suited to this kind of problem. The resulting discrete system of nonlinear equations is tackled with a trust-region algorithm, whose performance is much enhanced by the analytic Jacobian which is provided alongside. Preliminary results up to Re = 60 with just 1292 nodes are shown.F. Bernal acknowledges support from FCT grant SFRH/BPD/79986/2011 and INESC-ID. A. Heryudono is partially supported by NSF Grant DMS 1552238Publicad

    In silicoAnalysis of the Structural Properties of PSMA and its Energetic Relationship with Zn as Cofactor

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    The prostate-specific membrane antigen (PSMA) is a 100 kDa type II transmembrane glycoprotein with enzymatic activity similar to the family of zinc-dependent exopeptidases. This protein is of great medical and pharmacological interest as overexpression in prostate cells is related to the progression of prostate cancer; therefore, it represents an important target for the design of radiopharmaceuticals. The presence of two Zn2+ ions in the active site is crucial to the enzymatic activity and the design of high-affinity inhibitors. The amino acid residues coordinating these ions are highly conserved in PSMA orthologs from plants to mammals, and site-mutagenesis assays of these residues show a loss of enzymatic function or reduction of the kinetic parameters. In the present work, we performed molecular dynamics simulation of PSMA with the purpose of characterizing it energetically and structurally. We elucidated the differences of PSMA with its two Zn+2 ions as cofactors and without them in the free energy profile, and in four structural parameters: root mean square deviations and root mean square fluctuations by atom and amino acid residue, radius of gyration, and solvent accessible surface area

    Design study of flapping foil propulsion for an Odyssey Class AUV

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    Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.Includes bibliographical references (leaves 56-57).A design study was conducted to examine the feasibility of implementing fish-like flapping foil propulsion on an Odyssey Class autonomous underwater vehicle (AUV). Theoretically, fish-like propulsion offers higher efficiencies, greater maneuverability, and the potential for faster accelerations than the conventional propulsion system currently in use on the Odyssey Class AUV. Previous laboratory research has shown promising results, and retrofitting an Odyssey Class AUV with a flapping foil is a cost-effective way to step up the learning curve toward applying this technology in a field setting. Based primarily on MIT's RoboTuna research on the swimming motions of fish, the proposed design hopes to achieve a speed of 1.5 m/s. Oscillating two tail links independently at a tail flapping frequency of about 1 Hz should provide this performance. The links are driven with DC brushless motor systems through a Scotch yoke linkage and a linear actuator. Pitch and roll motion is accomplished with the addition of servo actuated pectoral fins, while dorsal and anal fins provide additional directional stability. A variety of motion schemes were contemplated, but the final design was chosen with an emphasis on simplicity, practicality, and robustness for use in a field setting.by Rafael A. Mandujano.S.B

    Structural Variations Induced by Temperature Changes in Rotavirus VP6 Protein Immersed in an Electric Field and Their Effects on Epitopes of The Region 300-396

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    Rotavirus diarrhea is an infectious intestinal disease that causes about 215 thousand deaths annually in infants under five years old. This virus is formed by three layers of concentric proteins that envelop its genome, from which VP6 structural protein is the most conserved among rotavirus serotypes and an excellent vaccine candidate. Recent studies have shown that structural proteins are susceptible to losing their biological function when their conformation is modified by moderate temperature increments, and in the case of VP6, its antigen efficiency decreases. We performed an in silicoanalysis to identify the structural variations in the epitopes 301-315, 357-366, and 376-384 of the rotavirus VP6 protein -in a hydrated medium- when the temperature is increased from 310 K to 322 K. In the latter state, we applied an electric field equivalent to a low energy laser pulse and calculated the fluctuations per amino acid residue. We identified that the region 301-315 has greater flexibility and density of negative electrical charge; nevertheless, at 322 K it experiences a sudden change of secondary structure that could decrease its efficiency as an antigenic determinant. The applied electric field induces electrical neutrality in the region 357-366, whereas in 376-384 inverts the charge, implying that temperature changes in the range 310 K-322 K are a factor that promotes thermoelectric effects in the VP6 protein epitopes in the region 300-396

    Time-space reproductive differences of black hakes, M. polli and M. senegalensis off the NW African Coast

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    PosterThe named black hake in the Northwest Africa, M. polli and M. senegalensis, are distributed in Saharan, Mauritanian and Senegalese waters, where they are target species of Spanish trawling fleet and by some longliners. The separation of both species is quite difficult in practice, hence they are usually considered as black hake (mixed) in commercial catch statistics. This fact and the considerable deep distribution range of M. polli, results in a marked scarcity of comparative detailed studies about these species. The aim of this work was to analyze detailed biological data, collected during research trawl surveys and scientific observations onboard of commercial trawlers and longilenrs in Mauritanian and Senegalese waters during 2003-2006. By macroscopic analysis of the gonadic stages and the seasonal evolution of gonadosomatic indices (GSI), it has been determined the spawning season of both species. In order to determine the size at first sexual maturity, a logistic model was fitted to the mature fraction by length separated by species, considering different time periods. In other hand, the monthly time series of commercial gonad yields between 1986 and 2006 were split up in the trend and the seasonal components using a X-12 ARIMA routine. The spawning took place during the cold season, from November to February with the strongest signal during December-January for both species, but it occurs quite early in M. senegalensis. Males consistently maturing earlier than females, but there was a little length difference of sexual maturity for the two species. M. senegalensis reached the first maturity (35,4 cm) at slightly lower length than M. polli (37,0 cm) for combined sexes model. The sex ratio was skewed to females in both species. Because these species inhabits into a highly dynamic oceanographic area, and taking in account that recently it has been suggested a strong dependence between the climate-environment proxy NAO and the black hakes adult abundance dynamics, we explored possible deterministic relationships between reproduction features and sexual maturity of both species in phase with NAO index. It was not possible to determine if the difference in length-maturity values with some previous analyses were related with changes in abundance, the environmental forcing, or due to calculus procedures. However there was synchrony between the pronounced negative NAO phase and decreasing amplitude of seasonal peak of gonad yields for both species. Finally, despite of there was a slightly asynchrony in spawning timing among both species, we believe that in general terms it is justified to consider one set of maturity parameter values to perform the assessment procedures.Instituto Español de Oceanografía (IEO

    Theoretical Model to Estimate the Distribution of Radon in Alveolar Membrane Neighborhood

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    Radon is a naturally occurring radioactive gas which tends to concentrate indoors, easily emanates from the ground into the air, where it disintegrates and emits radioactive particles. It can enter the human body through breathing or ingesting mostly water. When radon inhaled, travels through the respiratory tract to alveoli where the majority is expelled into the environment. Moreover, when ingested in water, it passes into the intestine where it is absorbed and driven from the bloodstream to the lungs; in these organs, due to differences in partial pressures, it is transported to alveoli by simple diffusion process. When radon is not removed, it decays in short-lived solid disintegration products (218Po and 214Po) with high probability of being deposited in biological tissues, causing DNA damage because of the densely ionizing alpha radiation emitted. We propose a semi-empirical, smooth, and continuous pair potential function in order to model the molecular interactions between radon and lung alveolar walls; we use Molecular Dynamics (MD) to determine the gas distribution in an alveolar neighborhood wall, and estimate the quantity thereof it diffuses through the alveolar membrane as a concentration function

    First Record of the Invasive Asian Fish Tapeworm \u3ci\u3eBothriocephalus acheilognathi\u3c/i\u3e in Honduras, Central America

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    This paper provides the first report of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934, in Honduras. The cestode was found in Profundulus portillorum (Cyprinodontiformes: Profundulidae), which represents a new host record, and which is a member of a genus faced with a variety of conservation challenges, now potentially complicated by the presence of this pathogenic cestode. Nearly complete sequence data from the ITS-1 5.8S and ITS-2 regions corroborate the determination based on morphological characteristics. Several species of carp were introduced to Honduras for aquaculture purposes in the early 1980s and the presence of the Asian fish tapeworm in Honduras may be related to these introductions. In addition, this report documents the currently known geographical distribution of this parasite in Central America, first recorded from Panamá and now from Honduras
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