Produção e ciclagem de nutrientes por plantas de cobertura nas culturas de arroz de terras altas e de soja.

As plantas de cobertura em sistema de plantio direto pode contribuir na formação de palhada e ciclagem de nutrientes para as culturas em sucessão. O objetivo deste trabalho foi avaliar a produção de matéria seca e ciclagem de nutrientes por plantas de cobertura semeadas em safrinha no desempenho do arroz de terras altas e da soja semeados em rotação, em sistemas plantio direto e preparo convencional, em Latossolo Vermelho do município de Rio Verde, Goiás. O estudo foi realizado no período de abril de 2008 a abril de 2010. Utilizou-se o delineamento em faixas com fatorial 2 x 5 com quatro repetições. Nas faixas horizontais foram testados os dois sistemas de manejo do solo (plantio direto e convencional) e nas faixas verticais, as plantas de cobertura. As avaliações de matéria seca, taxa de cobertura do solo e ciclagem de nutrientes foram realizadas apenas nos tratamentos plantio direto, em que as parcelas foram subdivididas em seis épocas de coletas de matéria seca após a dessecação das plantas de cobertura, o que ocorreu aos 0, 15, 30, 60, 90 e 120 dias a partir da dessecação de manejo das plantas de cobertura, perfazendo um fatorial 5 x 6. As plantas de cobertura, semeadas em safrinha, foram as seguintes: Brachiaria brizantha, B. ruziziensis, Pennisetum glaucum e B. ruziziensis + Cajanus cajan e o pousio. Avaliaram-se a produção de matéria seca, a taxa de cobertura do solo, o acúmulo e liberação de nutrientes pelas plantas de cobertura e a produtividade do arroz na safra 2008/09 e da soja na safra 2009/10, semeados em rotação. As espécies B. ruziziensis e B. ruziziensis + C. cajan destacaram-se na produção de matéria seca, taxa de cobertura do solo e acúmulo de nutrientes no final do período de entressafra. Os nutrientes com mais acúmulos nas matérias secas foram N e K, e as maiores taxas de liberação no solo foram observadas nos elementos K e P. As maiores produtividades de arroz sob plantio direto foram obtidas sobre palhadas de P. glaucum e B. ruziziensis, enquanto a cultura da soja não apresentou diferenças em sua produtividade nos tratamentos estudados

Ciclagem de nutrientes por plantas de cobertura no cerrado.

O objetivo deste trabalho foi avaliar o desempenho de plantas cultivadas quanto ao acúmulo e a liberação de nutrientes, durante o período de entressafra, em um Latossolo Vermelho distroférrico de Santo Antônio de Goiás, GO e Rio Verde, GO. O delineamento experimental foi o de blocos casualizados, em esquema de parcelas subdivididas no tempo, com as plantas de cobertura avaliadas nas parcelas, e nas subparcelas, as épocas de coleta de fitomassa, com quatro repetições

Produção de fitomassa por plantas de cobertura no cerrado.

O objetivo do trabalho foi avaliar a produção de fitomassa por plantas de cobertura semeadas em safrinha no desempenho do arroz de terras altas e soja, semeada em rotação, em sistema de plantio direto e preparo convencional, em Latossolo Vermelho do município de Rio Verde, Goiás. O trabalho foi realizado no período de abril de 2008 a fevereiro de 2009. Utilizou-se o delineamento em faixas, em esquema de parcelas subdivididas no tempo, com quatro repetições. Nas faixas horizontais foram testadas as plantas de cobertura, nas faixas verticais dois sistemas de manejo (plantio direto e convencional, ambos com três anos de implantação), e nas subparcelas seis épocas de coletas de fitomassa após a dessecação das plantas de cobertura, que ocorreu aos 0 , 15, 30, 60, 90 e 120 dias à partir da dessecação de manejo das plantas de cobertura, com quatro repetições

Oral medicine, oral pathology and coronavirus (2019-nCoV): current challenges

In late December 2019, a cluster of unexplained pneumonia cases was diagnosed in Wuhan, China, and few days later, the causative agent of this mysterious pneumonia was identified as a novel coronavirus. This causative virus has been temporarily named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the relevant infected disease has been named as coronavirus disease 2019 (COVID-19) by the World Health Organization respectively. The COVID-19 epidemic is spreading in China and all over the world now..

Highlights from the Pierre Auger Observatory

The Pierre Auger Observatory is the world's largest cosmic ray observatory. Our current exposure reaches nearly 40,000 km$^2$ str and provides us with an unprecedented quality data set. The performance and stability of the detectors and their enhancements are described. Data analyses have led to a number of major breakthroughs. Among these we discuss the energy spectrum and the searches for large-scale anisotropies. We present analyses of our X$_{max}$ data and show how it can be interpreted in terms of mass composition. We also describe some new analyses that extract mass sensitive parameters from the 100% duty cycle SD data. A coherent interpretation of all these recent results opens new directions. The consequences regarding the cosmic ray composition and the properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray Conference, Rio de Janeiro 201

Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory

On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy above 100 PeV from point-like sources across the sky with equatorial declination from about -65 deg. to +60 deg., and in particular from a fraction of the 90% confidence-level (CL) inferred positions in the sky of GW150914 and GW151226. A targeted search for highly-inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within $\pm 500$ s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the non-observation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events.Comment: Published version. Added journal reference and DOI. Added Report Numbe

Environmental representativity in marine protected area networks over large and partly unexplored seascapes

Converting assemblages of marine protected areas (MPAs) into functional MPA networks requires political will, multidisciplinary information, coordinated action and time. We developed a new framework to assist planning environmental representativity in a network across the marine space of Portugal, responding to a political commitment to protect 14% of its area by 2020. An aggregate conservation value was estimated for each of the 27 habitats identified, from intertidal waters to the deep sea. This value was based on expert-judgment scoring for environmental properties and features relevant for conservation, chosen to reflect the strategic objectives of the network, thus providing an objective link between conservation commitments and habitat representativity in space. Additionally, habitats' vulnerability to existing anthropogenic pressures and sensitivity to climate change were also scored. The area coverage of each habitat in Portugal and within existing MPAs (regionally and nationally) was assigned to a scale of five orders of magnitude (from 10%) to assess rarity and existing representation. Aggregate conservation value per habitat was negatively correlated with area coverage, positively correlated with vulnerability and was not correlated with sensitivity. The proposed framework offers a multi-dimensional support tool for MPA network development, in particular regarding the prioritization of new habitats to protect, when the goal is to achieve specific targets while ensuring representativity across large areas and complex habitat mosaics. It requires less information and computation effort in comparison to more quantitative approaches, while still providing an objective instrument to scrutinize progress on the implementation of politically set conservation targets.Agência financiadora Número do subsídio Oceanic Observatory of Madeira M1420-01-0145-FEDER-000001-OOM national funds through FCT UID/BIA/00329/2013 UID/Multi/04326/2013 Fundacao para a Ciencia e a Tecnologia SFRH/BPD/95334/2013 CESAM - FCT/MEC through national funds UID/AMB/50017 - POCI-01-0145-FEDER-007638 FEDER FCT SFRH/BPD/94320/2013 MARE - UID/MAR/04292/2019 EU through the Cohesion Fund POSEUR-03-2215-FC-000046 POSEUR-03-2215-FC-000047 FCT national funds ECO/28687/2017info:eu-repo/semantics/publishedVersio

A search for point sources of EeV photons

Measurements of air showers made using the hybrid technique developed with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for point sources of EeV photons anywhere in the exposed sky. A multivariate analysis reduces the background of hadronic cosmic rays. The search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been detected. An upper limit on the photon flux has been derived for every direction. The mean value of the energy flux limit that results from this, assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in which EeV cosmic ray protons are emitted by non-transient sources in the Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical Journa