3,329 research outputs found

    Effect of the Substitution of Agricultural Uses by Forest on the Hydrological Processes in a Tropical Watershed. Analysis through Hydrological Simulation

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    Forests play an important role in watershed hydrology, regulating the transfer of water within the system. Their role in maintaining the hydrological regime of watersheds is still a controversial issue. Due to the uncertainty, our first objective was to identify, through GIS techniques, “Environmentally Sensitive Areas” (ESAs) in the Pinhal watershed, subsequently, to simulate land use scenarios with the Soil and Water Assessment Tool model. In one of these scenarios, we considered these areas as protected by forest cover. This scenario we compared to the current scenario regarding watershed sediment yield and hydrological processes. The results showed a reduction in sediment yield of 54% between the two scenarios, whereas watershed water yield was reduced by 19.3%

    Afforestation of savannas: an impending ecological disaster.

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    Made available in DSpace on 2018-08-04T00:53:27Z (GMT). No. of bitstreams: 1 1s2.0S1679007316300779main.pdf: 2087352 bytes, checksum: f7e5fc4f6f8dbc44cbc3b894fadca5f3 (MD5) Previous issue date: 2017-02-06bitstream/item/180899/1/1-s2.0-S1679007316300779-main.pd

    Synthesis of natural ether lipids and 1-O-hexadecylglycero-arylboronates via an epoxide-ring opening approach: Potential antifouling additives to marine paint coatings

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    In this paper a new and efficient procedure for the synthesis of natural 1-O- alkyl glyceryl ethers such as chimyl (1), batyl (2) and selachyl (3) is described. Alkyl glycidyl ethers (4-6) were synthetized using solvents free reactions. A stereospecific ring-opening reaction of epoxides (4-6) with phenylboronic acid in dry dioxane, giving rise to cyclic arylboronates in high yields (90-98%). Seven new 1-O-hexadecylglycero-arylboronates (7-f) and chimyl alcohol (1) were evaluated in laboratory antifouling assays

    Expressed sequenced tags profiling of resistant and susceptible Gyr x Holstein cattle infested with the tick Rhipicephalus (Boophilus) microplus.

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    Tick resistance in cattle is mainly found in zebu (Bos indicus) animals, although it is also present in some taurine (B. taurus) breeds. In order to characterize functional genes involved in tick resistance/susceptibility in cattle, two cDNA libraries were generated using skin tissues of selected Holstein x Gyr animals. A total of 2700 high-quality reads from both resistant and susceptible cDNA were assembled into 458 sequences (contigs) and 834 singletons, with a mean size of 447.7 nucleotides. Assignment of homologous proteins by BLASTX revealed 790 (61.1%) and 300 (23.2%) hits in resistant and susceptible cDNA, respectively; 121 of these hits matched bovine proteins. A total of 502 (38.9%) unique sequences were found to have no significant homology with known sequences and were classified as novel sequences. In general, the most abundant sequences consisted of those coding for hypothetical proteins whose function had not yet been determined, in addition to ribosomal proteins, binding proteins and structural proteins, such as keratin and collagen. The most abundant protein found was collagen type III alpha, although ribosomal proteins accounted for half of the 40 most frequent hits. In addition, five matches within the top 40 best hits corresponded to immune response proteins. These sequences could be used for future studies on functional genomics of cattle tick resistance as well as for genomic sequencing projects

    Expressed sequenced tags profiling of resistant and susceptible Gyr x Holstein cattle infested with the tick Rhipicephalus (Boophilus) microplus.

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    Tick resistance in cattle is mainly found in zebu (Bos indicus) animals, although it is also present in some taurine (B. taurus) breeds. In order to characterize functional genes involved in tick resistance/susceptibility in cattle, two cDNA libraries were generated using skin tissues of selected Holstein x Gyr animals. A total of 2700 high-quality reads from both resistant and susceptible cDNA were assembled into 458 sequences (contigs) and 834 singletons, with a mean size of 447.7 nucleotides. Assignment of homologous proteins by BLASTX revealed 790 (61.1%) and 300 (23.2%) hits in resistant and susceptible cDNA, respectively; 121 of these hits matched bovine proteins. A total of 502 (38.9%) unique sequences were found to have no significant homology with known sequences and were classified as novel sequences. In general, the most abundant sequences consisted of those coding for hypothetical proteins whose function had not yet been determined, in addition to ribosomal proteins, binding proteins and structural proteins, such as keratin and collagen. The most abundant protein found was collagen type III alpha, although ribosomal proteins accounted for half of the 40 most frequent hits. In addition, five matches within the top 40 best hits corresponded to immune response proteins. These sequences could be used for future studies on functional genomics of cattle tick resistance as well as for genomic sequencing projects.Projeto/Plano de Ação: 02.10.60.300-01

    LaMMos - Latching Mechanism based on Motorized-screw for Reconfigurable Robots and Exoskeleton Suits

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    Reconfigurable robots refer to a category of robots that their components (individual joints and links) can be assembled in multiple configurations and geometries. Most of existing latching mechanisms are based on physical tools such as hooks, cages or magnets, which limit the payload capacity. Therefore, robots re- quire a latching mechanism which can help to reconfigure itself without sacrificing the payload capability. This paper presents a latching mechanism based on the flexible screw attaching principle. In which, actuators are used to move the robot links and joints while connecting them with a motorized-screw and dis- connecting them by unfastening the screw. The brackets used in our mechanism configuration helps to hold maximum force up to 5000N. The LaMMos - Latching Mechanism based on Motorized- screw has been applied to the DeWaLoP - Developing Water Loss Prevention in-pipe robot. It helps the robot to shrink its body to crawl into the pipe with minimum diameter, by recon- figuring the leg positions. And it helps to recover the legs positions to original status once the robot is inside the pipe. Also, LaMMos add stiffness to the robot legs by dynamically integrate them to the structure. Additionally, we present an application of the LaMMos mechanism to exoskeleton suits, for easing the mo- tors from the joints when carrying heavy weights for long periods of time. This mechanism offers many interesting opportunities for robotics research in terms of functionality, pay- load and size.Comment: 14 pages, 15 figure

    Differential expression of genes in resistant versus susceptible Gyr x Holstein cattle challenged with the tick Rhipicephalus (Boophilus) microplus.

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    The bovine tick Rhipicephalus (Boophilus) microplus causes major losses in cattle production systems in tropical regions. Bos indicus breeds are more resistant to ticks than B. taurus breeds. Resistance genes could be an alternative to control this parasite. We examined the pattern of gene expression of three calcium-binding-protein genes: translationally controlled tumor protein 1 (TPT1), allergen Bos d3 (S100A7), calcium channel protein transient receptor potential vanilloid 6 (TRPV6), and the cysteine proteinase inhibitor gene (CST6). These genes were selected from cDNA libraries prepared from skin biopsies taken from resistant and susceptible Gyr x Holstein F₂ animals. These biopsies were also used to study the expression level of these genes through real-time PCR analysis. The relative expression levels of the S100A7, TPT1, TRPV6, and CST6 genes were 2.01 ± 0.6, 1.32 ± 0.9, 1.53 ± 1.2, and 2.03 ± 0.7 times higher in the susceptible group, respectively. Skin lesion tissue from the susceptible animals showed significantly more mRNA transcripts of these genes in comparison with the resistant animals (P = 0.001). However, this hypersensitivity does not seem to protect the susceptible animals against tick infestation

    Evaluation of drug susceptibility profile of; Mycobacterium tuberculosis; lineage 1 from Brazil based on whole genome sequencing and phenotypic methods

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    BACKGROUND: The evaluation of procedures for drug susceptibility prediction of Mycobacterium tuberculosis based on genomic data against the conventional reference method test based on culture is realistic considering the scenario of growing number of tools proposals based on whole-genome sequences (WGS). OBJECTIVES: This study aimed to evaluate drug susceptibility testing (DST) outcome based on WGS tools and the phenotypic methods performed on isolates of M. tuberculosis Lineage 1 from the state of Para, Brazil, generally associated with low levels of drug resistance. METHODOLOGY: Culture based DST was performed using the Proportion Method in Lowenstein-Jensen medium on 71 isolates that had been submitted to WGS. We analysed the seven main genome sequence-based tools for resistance and lineage prediction applied to M. tuberculosis and for comparison evaluation we have used the Kappa concordance test. FINDINGS: When comparing the WGS-based tools against the DST, we observed the highest level of agreement using TB-profiler. Among the tools, TB-profiler, KvarQ and Mykrobe were those which identified the largest number of TB-MDR cases. Comparing the four most sensitive tools regarding resistance prediction, agreement was observed for 43 genomes. MAIN CONCLUSIONS: Drug resistance profiling using next-generation sequencing offers rapid assessment of resistance-associated mutations, therefore facilitating rapid access to effective treatment
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