43 research outputs found

    Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations

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    We report the most sensitive upper limits to date on the 21 cm epoch of reionization power spectrum using 94 nights of observing with Phase I of the Hydrogen Epoch of Reionization Array (HERA). Using similar analysis techniques as in previously reported limits (HERA Collaboration 2022a), we find at 95% confidence that Δ2(k=0.34\Delta^2(k = 0.34 hh Mpc1^{-1}) 457\leq 457 mK2^2 at z=7.9z = 7.9 and that Δ2(k=0.36\Delta^2 (k = 0.36 hh Mpc1)3,496^{-1}) \leq 3,496 mK2^2 at z=10.4z = 10.4, an improvement by a factor of 2.1 and 2.6 respectively. These limits are mostly consistent with thermal noise over a wide range of kk after our data quality cuts, despite performing a relatively conservative analysis designed to minimize signal loss. Our results are validated with both statistical tests on the data and end-to-end pipeline simulations. We also report updated constraints on the astrophysics of reionization and the cosmic dawn. Using multiple independent modeling and inference techniques previously employed by HERA Collaboration (2022b), we find that the intergalactic medium must have been heated above the adiabatic cooling limit at least as early as z=10.4z = 10.4, ruling out a broad set of so-called "cold reionization" scenarios. If this heating is due to high-mass X-ray binaries during the cosmic dawn, as is generally believed, our result's 99% credible interval excludes the local relationship between soft X-ray luminosity and star formation and thus requires heating driven by evolved low-metallicity stars.Comment: 57 pages, 37 figures. Updated to match the accepted ApJ version. Corresponding author: Joshua S. Dillo

    Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

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    Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Development of an electronic profilometer to measure mobilization variables in soil harrowing

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    Aim of study: This experiment's objective is to develop an automatic data acquisition system for profilometry, evaluating four harrowing speeds. Area of study: Federal University of Parana, Curitiba, Brazil. Material and methods: We experimented at the laboratory using a completely randomized design, comparing the data of modified roughness, raised and mobilized area, blistering, and thickness. These were acquired with traditional and electronic profilometers in seven replications. We executed the field test in lines, using a completely randomized design. The profilometers were in the plots and the targeted speeds in the subplots. We submitted the data for analysis of variance and when significant, to Tukey's test and regression analysis. Main results: Laboratory testing showed no significant difference in the parameters of modified roughness, elevated and mobilized area, blistering, and thickness, denoting the phase validation that indicates applicability in the field. The field testing presented superior results for the electronic profilometer in elevated and mobilized areas and soil layer thickness. That is due to the absence of interference in the measurements that occur in the conventional profilometer caused by the insertion of the rods in the soil. Research highlights: The increase in the mechanized set speed provided the reduction of the elevated area and soil blistering caused by the rise in disc rotation and consequent deviation of the soil particles

    Semeadora-adubadora: mecanismos de corte de palha e cargas verticais aplicadas

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    This work had as objective to evaluate the performance of mechanisms of cutting of the no-tillage seedrills in different vegetable coverings and applied vertical loads. The experimental design used was in randomized blocks and factorial scheme 3 x 4, with four replications. The trials were accomplished with three different mechanisms of culting of the straw (plane disc, corrugated disc and wavy disc), using four different vertical loads (750, 1500, 2250 and 3000 N). All treatments were accomplished in five straw coverings (corn, sorghum, triticale, black oats and radish). The results showed that larger the amount of dry matter covering the soil, higher the demand of horizontal and vertical forces. The wavy disc promotes the largest values of area of mobilized soil and requires large horizontal force, vertical force and horizontal force per area of cutting depth of discs (specific force). The treatment with plane disc required higher values of the horizontal forces per area of mobilized soil and of vertical force in the corn and sorghum coverings

    Eficiência fotossintética da cana-de-açúcar submetida à aplicação de atrazine e tebuthiuron em pré-emergência

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    The objective of this work was to assess the photosynthetic efficiency of sugarcane crop, in pre-emergency application, of two inhibiting photosynthesis herbicides. For sugar cane cuttings planting (SP80-3280 genotype), pots with a capacity of 8 dm3 were used. Atrazine and tebuthiuron application was performed by using a stationary spray installed in laboratory conditions and after treatment application, plants were transported to a green house where were kept until the end of the trial. The reading of electrons transport rate (ETR) was conducted in the middle portion of the youngest leaves of sugarcane with a portable fluorometer, with intervals for ETR assessment constituted by: 16, 17, 19, 25 and 30 days after herbicide application. It was also developed visual analysis of phytotoxiciy performed 30 days after application. The results showed that tebuthiuron herbicide caused greater reduction in electrons transport rate than atrazine. In relation to herbicide symptoms, there was no significant difference between the studied herbicides. At the end of the study it could be verified that the chosen methodology by using fluorometer to measure the electrons transport rate after herbicide application was adequate, allowing verifying sugar cane crop intoxication, even before any visual detection of herbicides performance in plants.O objetivo do trabalho foi avaliar a eficiência fotossintética da cana-de-açúcar após aplicação, em pré-emergência, de dois herbicidas inibidores da fotossíntese. Para o plantio dos toletes da cana-de-açúcar (variedade SP80-3280), utilizaram-se vasos com capacidade de 8 dm3 . A aplicação do atrazine e tebuthiuron foi realizada através de um pulverizador estacionário instalado em laboratório e após a aplicação dos tratamentos, as plantas foram transportadas para casa-de-vegetação onde ficaram até o término do ensaio. Realizou-se a leitura da taxa de transporte de elétrons (ETR) na porção mediana das folhas mais novas de cana-de-açúcar com fluorômetro portátil sendo que os intervalos de avaliação do ETR foram de: 16, 17, 19, 25 e 30 dias após a aplicação dos herbicidas. Realizou-se ainda análise visual de fitointoxicação aos 30 dias após aplicação. Os resultados demonstraram que o tebuthiuron causou maior redução da taxa de transporte de elétrons em comparação com a atrazine. Em relação aos sintomas de fitointoxicação, não foi observada diferença entre os herbicidas testados. Ao fim do trabalho, verificou-se que a metodologia empregada com o uso do fluorômetro para medir a taxa de transporte de elétrons após a aplicação dos herbicidas foi adequada, permitindo verificar a intoxicação da cultura de cana-de-açúcar, mesmo antes de qualquer detecção visual da atuação dos herbicidas nas plantas

    Viabilidade econômica de aquisição de um silo-secador para pequenas áreas de produção Economic viability acquisition of a drying-storing facility, designed for small farms

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    O objetivo deste trabalho foi avaliar, por meio de simulação econômica, a viabilidade de aquisição de um silo-secador, para pequenas propriedades rurais, tendo como referências as opções de terceirizar o processo de secagem/armazenagem ou a comercialização do milho úmido. Em virtude da alta diversificação encontrada nas pequenas propriedades rurais, a simulação foi realizada considerando-se diferentes tamanhos de áreas exploradas com milho (10; 20; 30 e 40 ha), níveis de produtividade (3.900; 4.500 e 5.100 kg ha-1) e preços por saca de milho (R13,03;R 13,03; R 19,69 e R34,29),noEstadodeSa~oPaulo.Comparandoasrentabilidadesobtidas,notouseasuperioridadedareceitalıˊquidanaaquisic\ca~odosilosecadornasaˊreasdeproduc\ca~ode20hacomprodutividadede4.500e5.100kgha1,30hae40hanosvaˊriosnıˊveisdeprodutividade(3.900;4.500e5.100kgha1)semprequeoprec\codemercadodasacademilhocobriuoscustosanuaisdosistema.Aterceirizac\ca~odasecagem/armazenagemapresentousecomoamelhoralternativanasaˊreasde10ha(todasasprodutividades)e20ha(produtividadede3.900kgha1).Acomercializac\ca~odoprodutouˊmidonuncaseconstituiunaopc\ca~omaisrentaˊvel.<br>Theaimofthisworkwastoevaluate,byusingeconomicalsimulation,theviabilitytogetadryingstoringfacility,forsmallfarms.Thisoptionwascomparedwithtwoothersconditions:topaytheprocessingortomarkethighmoisturecontentgrains.Thestudywascarriedoutinpropertieswith10;20;30and40ha,productivitylevelsof3,900;4,500and5,100kgha1andpricesforcornbag(60kg)ofR 34,29), no Estado de São Paulo. Comparando as rentabilidades obtidas, notou-se a superioridade da receita líquida na aquisição do silo secador nas áreas de produção de 20 ha com produtividade de 4.500 e 5.100 kg ha-1, 30 ha e 40 ha nos vários níveis de produtividade (3.900; 4.500 e 5.100 kg ha-1) sempre que o preço de mercado da saca de milho cobriu os custos anuais do sistema. A terceirização da secagem/armazenagem apresentou-se como a melhor alternativa nas áreas de 10 ha (todas as produtividades) e 20 ha (produtividade de 3.900 kg ha-1). A comercialização do produto úmido nunca se constituiu na opção mais rentável.<br>The aim of this work was to evaluate, by using economical simulation, the viability to get a drying-storing facility, for small farms. This option was compared with two others conditions: to pay the processing or to market high moisture content grains. The study was carried out in properties with 10; 20; 30 and 40 ha, productivity levels of 3,900; 4,500 and 5,100 kg ha-1 and prices for corn bag (60 kg) of R 13.03, R19.69andR 19.69 and R 34.29, in the State of Sao Paulo, Brazil. The results indicated the superiority of the profits to get the drying-storing facility option for properties with 20 ha (productivity levels of 4,500 and 5,100 kg ha-1), 30 ha and 40 ha, while to pay the processing (drying and storage) showed a better option for properties with 10 ha (all productivity levels) and 20 ha (3,900 kg ha-1). To market high moisture content grains option never provided the best profitability

    Análise Energética da cultura do crambe (Crambe abyssinica hochst) produzida em plantio direto Analysis of Energy in the crambe culture (Crambe abyssinica hochst) produced in no tillage

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    O objetivo deste trabalho foi caracterizar o consumo de energia na implantação e condução da cultura do Crambe abyssinica Hochst, em sistema de plantio direto, na Fazenda Experimental Lageado, pertencente à Faculdade de Ciências Agronômicas - UNESP, localizada no município de Botucatu - SP. Avaliando a sustentabilidade do sistema, estimaram-se, a eficiência energética e a cultura do crambe. Para o levantamento dos componentes da estrutura de dispêndios, foram utilizados coeficientes energéticos preconizados em literaturas especializadas. As estruturas de dispêndios energéticos por tipo, fonte e forma demonstraram que a energia indireta participou com 65,03%; as fontes industrial, fóssil e biológica representaram 68,80%, 23,67% e 11,30%, respectivamente. Quanto às formas em que se apresentaram, os fertilizantes químicos contribuíram com 44,31%, e o óleo diesel, com 23,04%, totalizando 67,35% do dispêndio energético, evidenciando a dependência do sistema das fontes energéticas industriais e fósseis. A eficiência da cultura encontrada foi de 9,98, apontando que, para cada unidade calórica aplicada na produção do crambe, o retorno foi de 8,98 unidades, a eficiência energética foi superior a 38, demonstrando alta sustentabilidade do sistema agrícola, tendo atingido energia cultural superior a 37 mil MJ ha-1.<br>The objective of this study was to characterize the energy consumption in the deployment and conduction of the culture of Crambe abyssinica Hochst in no-tillage, at the Experimental Farm belonging to the Faculty of Agronomic Sciences - UNESP, located in Botucatu - SP, Brazil. Assessing the sustainability of the system were estimated, energy efficiency and culture of crambe. To survey the components of the structure of expenditures, it was used Energetic coefficients in specialized literature. The structures of energy expenditure by type, source and form, demonstrated that the indirect energy participated with 65.03%, industrial sources, fossil and biological accounted for 68.80%, 23.67% and 11.30%, respectively. The forms have been introduced; chemical fertilizers contributed 44.31% and diesel to 23.04% to 67.35% of energy expenditure, showing the dependence of the system of energy sources and industrial fuels. The efficiency of the culture was found to be 9.98, indicating that for each calorie used in the production of crambe return was 8.98 units, the efficiency was above 38, demonstrating the high sustainability of the agricultural system to reach energy cultural exceeding 37 thousand MJ ha-1
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