491 research outputs found

    WORKSHOP A Cultura do Mirtilo

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    O workshop teve como objectivo transmitir conhecimentos em diferentes åreas da produção e comercializção de mirtilo

    Wild meat trade over the last 45 years in the Peruvian Amazon

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    The trade in wild meat is an important economic component of rural people's livelihoods, but it has been perceived to be among the main causes of the decline of wildlife species. Recently, the COVID-19 pandemic has brought to light an additional concern of wildlife markets as a major human-health challenge. We analyzed data from the largest longitudinal monitoring (1973–2018) of the most important urban wild-meat markets in Iquitos, Peru, to examine the trends in and impacts of these markets on people's livelihoods. Over the last 45 years, wild meat sales increased at a rate of 6.4 t/year (SD 2.17), paralleling urban population growth. Wild meat sales were highest in 2018 (442 t), contributing US$2.6 million (0.76%) to the regional gross domestic product. Five species of ungulates and rodents accounted for 88.5% of the amount of biomass traded. Vulnerable and Endangered species represented 7.0% and 0.4% of individuals sold, respectively. Despite growth in sales, the contribution of wild meat to overall urban diet was constant: 1–2%/year of total meat consumed. This result was due to greater availability and higher consumption of cheaper meats (e.g., in 2018, poultry was 45.8% cheaper and was the most consumed meat) coupled with the lack of economic incentives to harvest wild meat species in rural areas. Most wild meat was sold salted or smoked, reducing the likelihood of foodborne diseases. Community-based wildlife management plans and the continued trade bans on primates and threatened taxa may avoid biodiversity loss. Considering the recent COVID-19 pandemic, future management plans should include potential viral hosts and regulation and enforcement of hygiene practices in wild-meat markets

    Modelling Clock Synchronization in the Chess gMAC WSN Protocol

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    We present a detailled timed automata model of the clock synchronization algorithm that is currently being used in a wireless sensor network (WSN) that has been developed by the Dutch company Chess. Using the Uppaal model checker, we establish that in certain cases a static, fully synchronized network may eventually become unsynchronized if the current algorithm is used, even in a setting with infinitesimal clock drifts

    Allelopathic action of some weed extracts on rice germination

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    O efeito do extrato aquoso de três plantas daninhas, Cynodon dactylon (l.)Pers., Cyperus rotundus l. e Sorghum halepense (l.) Pers. sobre a germinação e o crescimento de plântulas de arroz (Oryza salina L. cv. IAC-165) foi estudado, com a finalidade de investigar a sensibilidade do arroz aos efeitos alelopåticos dessas plantas. Foram utilizados, na preparação dos extratos, raizes de Cynodon daclylon, tubÊrculos de Cyperus rolundus: e riomas de Sorglun halepense, os quais foram homoneizados em solução aquosa, submetidos a filtração e centrifugação. O sobrenadante foi aplicado no substrato de germinação das sementes, verificando-se, aos sete dias após a se meadura, que apenas os extratos de Cy-nodon daetylon e Sorghum halepense afetaram a porcentagem de germinação das sementes de arroz. Entretanto, o crescimento da radícula e da parte aÊrea das plântulas foi prejudicado pelos três extratos testados, sendo o efeito mais dråstico causado pelo extrato de Cyperus, retundus.The present study was carried out to evaluate the possible allelopathic effects of Cynodon dactylon, Cyperus rotundus and Sorghum halepense on seed germination of Oryza sativa cv. IAC-165. Extracts from roots of Cynodon dactylon and Sorghum halepense and from tubers of Cyperus rotundas were used to evaluate the effects on rice seed germination. Aqueous solution of these organs, obtained by homogenization, filtration and centrifugation, were introduced on Petri dishes containing rice seeds. The evaluation of germination and initial growth showed a strong negative allelopathic effect of all three weeds studied

    Allelopathic action of some weed extracts on rice germination

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    O efeito do extrato aquoso de três plantas daninhas, Cynodon dactylon (l.)Pers., Cyperus rotundus l. e Sorghum halepense (l.) Pers. sobre a germinação e o crescimento de plântulas de arroz (Oryza salina L. cv. IAC-165) foi estudado, com a finalidade de investigar a sensibilidade do arroz aos efeitos alelopåticos dessas plantas. Foram utilizados, na preparação dos extratos, raizes de Cynodon daclylon, tubÊrculos de Cyperus rolundus: e riomas de Sorglun halepense, os quais foram homoneizados em solução aquosa, submetidos a filtração e centrifugação. O sobrenadante foi aplicado no substrato de germinação das sementes, verificando-se, aos sete dias após a se meadura, que apenas os extratos de Cy-nodon daetylon e Sorghum halepense afetaram a porcentagem de germinação das sementes de arroz. Entretanto, o crescimento da radícula e da parte aÊrea das plântulas foi prejudicado pelos três extratos testados, sendo o efeito mais dråstico causado pelo extrato de Cyperus, retundus.The present study was carried out to evaluate the possible allelopathic effects of Cynodon dactylon, Cyperus rotundus and Sorghum halepense on seed germination of Oryza sativa cv. IAC-165. Extracts from roots of Cynodon dactylon and Sorghum halepense and from tubers of Cyperus rotundas were used to evaluate the effects on rice seed germination. Aqueous solution of these organs, obtained by homogenization, filtration and centrifugation, were introduced on Petri dishes containing rice seeds. The evaluation of germination and initial growth showed a strong negative allelopathic effect of all three weeds studied

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

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    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO

    BiotecnologĂ­a de plantas superiores y algas verdes

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    Los ureidos, alantoĂ­na y alantoato, son los principales compuestos sintetizados a partir del nitrĂłgeno fijado en los nĂłdulos de las leguminosas que se exportan a las partes aĂŠreas en leguminosas tropicales como la judĂ­a. Los ureidos se producen por la oxidaciĂłn de las purinas sintetizadas de novo en los nĂłdulos radicales y tambiĂŠn como parte de un proceso de recuperaciĂłn de los compuestos nitrogenados en tejidos senescentes. Los ureidos se acumulan en varios tejidos vegetales en respuesta al estrĂŠs hĂ­drico, y se ha sugerido que la acumulaciĂłn de estos compuestos nitrogenados es la responsable de la inhibiciĂłn de la fijaciĂłn de nitrĂłgeno que tiene lugar en condiciones ambientales adversas. A pesar de la importancia crucial de los ureidos como compuestos de reserva y transporte de nitrĂłgeno, hasta el momento no se llevado a cabo la caracterizaciĂłn de las rutas de sĂ­ntesis y degradaciĂłn de ureidos en plantas. En particular, parece que existen dos posibles rutas de degradaciĂłn de alantoato, y que el que determinadas leguminosas usen una u otra ruta puede afectar a la sensibilidad o tolerancia de esas plantas a la sequĂ­a. Por tanto la determinaciĂłn de la ruta que opera en leguminosas de gran interĂŠs agronĂłmico como la judĂ­a y el garbanzo, puede a la larga tener utilidad biotecnolĂłgica con la obtenciĂłn de plantas que sean capaces de mantener la fijaciĂłn de nitrĂłgeno en condiciones ambientales adversas, como la sequĂ­a. AdemĂĄs de en la caracterizaciĂłn, con fines biotecnolĂłgicos del metabolismo de ureidos en leguminosas, se estĂĄ trabajando obtenciĂłn de algas superproductoras de Îł-tocoferol (vitamina E) mediante ingenierĂ­a metabĂłlica, asĂ­ como en el anĂĄlisis del contenido en antioxidantes del aceite de oliv
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