2,000 research outputs found

    Mating behaviour and reproductive output in insecticide-resistant and -susceptible strains of the maize weevil (\u3ci\u3eSitophilus zeamais\u3c/i\u3e)

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    Insecticide resistance is a broadly recognised and well-studied management problem resulting from intensive insecticide use, which also provides useful evolutionary models of newly adapted phenotypes to changing environments. Two common assumptions in such models are the existence of fitness costs associated with insecticide resistance, which will place the resistant individuals at a disadvantage in insecticide-free environments, and the prevalence of random mating among insecticide-resistant and -susceptible individuals. However, cases of insecticide resistance lacking apparent fitness disadvantages do exist impacting the evolution and management of insecticide resistance. Assortative mating, although rarely considered, may also favour the evolution and spread of insecticide resistance. Thus, the possible existence of both conditions in the maize weevil (Sitophilus zeamais), a key pest of stored cereals, led to the assessment of the mating behaviour and reproductive fitness of insecticide-resistant and -susceptible weevil strains and their reciprocal crosses. The patterns of female and male mating choice also were assessed. Although mating behaviour within and between weevil strains was similar without mate choice, mating within the resistant strain led to higher reproductive output than within the susceptible strain; inter-strain matings led to even higher fertility. Thus, no apparent fitness cost associated with resistance seems to exist in these weevils, favouring the evolution of this phenotype that is further aided by the higher fertility of inter-strain matings. Mate choice reduced latency to mate and no inter-strain preference was detected, but female weevils were consistent in their mate selection between 1st and 2nd matings indicating existence of female mating preference among maize weevils. Therefore, if female mate selection comes to favour trait(s) associated with insecticide resistance, higher reproductive fitness will be the outcome of such matings favouring the evolution and spread of insecticide resistance among maize weevil populations reverting into a management concern

    Quantum Kalb-Ramond Field in D-dimensional de Sitter Spacetimes

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    In this work we investigate the quantum theory of the Kalb-Ramond fields propagating in DD-dimensional de Sitter spacetimes using the dynamic invariant method developed by Lewis and Riesenfeld [J. Math. Phys. 10, 1458 (1969)] to obtain the solution of the time-dependent Schr\"odinger equation. The wave function is written in terms of a cc-number quantity satisfying of the Milne-Pinney equation, whose solution can be expressed in terms of two independent solutions of the respective equation of motion. We obtain the exact solution for the quantum Kalb-Ramond field in the de Sitter background and discuss its relation with the Cremmer-Scherk-Kalb-Ramond model

    Regular physical activity-related awareness and knowledge in Portugal: results from a population-based survey

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    Background: Previous studies have shown that adequate physical activity (PA, defined as any bodily movement that requires energy expenditure) related awareness and knowledge is crucial to promote regular PA. Therefore, this study aims to characterize PA awareness and knowledge, and to quantify its association with sociodemographic characteristics, health literacy and frequency of exercise. Methods: In a cross-sectional study conducted in 2012, a total of 1624 Portuguese-speaking residents of mainland Portugal (16–79 years old) were assessed through face-to-face interviews using a structured questionnaire. Adjusted prevalence ratios, calculated using Poisson regression, were used to quantify associations with PA awareness and knowledge. Results: The most reported benefits of PA were “reduces abdominal fat accumulation” (95.8%), “reduces myocardial infarction risk” (92.9%) and “improves bone health” (90.7%), these were less referred by older participants, while more often identified by those who exercise daily. The most referred barrier for people to not practice PA regularly was “lack of time” (33.9%) with differences observed by sex, age, education, employment and health literacy. Over two-thirds of participants correctly identified at least 2 of 3 PAs (“running”, “soccer” and “tennis”) that require the most energy, particularly males, those with higher health literacy and who exercise twice or more times a week. Conclusions: An adequate PA-related awareness and knowledge was observed, and differences according to age, health literacy levels and frequency of exercise were found. As such, awareness-raising interventions to increase regular PA through improving physical literacy and motivation should focus on older adults, those with limited health literacy and who do not exercise.Financial support and sponsorship: This study was supported by FEDER funds through Operational Programme Competitiveness and Internationalization and by national funding from The Portuguese Foundation for Science and Technology – FCT (Portuguese Ministry of Education and Science) within the project (HMSPIISE/SAU-ICT/0004/2009) and the Epidemiology Research Unit – Institute of Public Health, University of Porto (EPIUnit; info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB/04750/2020/PT). SM was funded under the scope of the project "NEON-PC - Neuro-oncological complications of prostate cancer: longitudinal study of cognitive decline" (POCI-01-0145-FEDER-032358; Ref. PTDC/SAU-EPI/32358/2017). An individual grant attributed to ARC (SFRH/BD/102181/2014) was co-funded by FCT and the “Programa Operacional Capital Humano” (POCH/FSE). The funding sources had no role in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication

    Recomendações para ajustes nas normativas sobre manejo de cipó-titica no estado do Amapá.

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    O cipó-titica (Heteropsis flexuosa (Kunth) G. S. Bunting) é um dos produtos florestais não madeireiros (PFNM) mais importantes para o estado do Amapá, do ponto de vista social e econômico, ficando atrás apenas do açaí e da castanha-da-amazônia. A raiz da planta adulta é considerada uma preciosa matéria- prima, usada por artesãos para confecção de utensílios e objeto de decoração. Também é muito utilizada por moveleiros para a fabricação de móveis sofisticados.bitstream/item/223838/1/CPAF-AP-2020-NT-004-Cipo-titica.pdf(Nota técnica, 4)

    Carbono orgânico total e suas frações físicas em latossolo vermelho cultivado com hortaliças em sistemas conservacionistas.

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    O presente trabalho teve como objetivo quantificar os teores de carbono orgânico total (COT) e suas frações físicas em um Latossolo Vermelho Distrófico cultivado com hortaliças em sistemas conservacionistas há seis anos

    Carbono das substancias húmicas em latossolo vermelho cultivado com hortaliças em sistemas conservacionistas.

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    O presente trabalho teve como objetivo quantificar os teores de carbono das substâncias húmicas em um Latossolo Vermelho Distrófico típico cultivado com hortaliças em sistemas conservacionistas há cinco anos

    Detection of a Hot Gaseous Halo Around the Giant Spiral Galaxy NGC 1961

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    Hot gaseous halos are predicted around all large galaxies and are critically important for our understanding of galaxy formation, but they have never been detected at distances beyond a few kpc around a spiral galaxy. We used the Chandra ACIS-I instrument to search for diffuse X-ray emission around an ideal candidate galaxy: the isolated giant spiral NGC 1961. We observed four quadrants around the galaxy for 30 ks each, carefully subtracting background and point source emission, and found diffuse emission that appears to extend to 40-50 kpc. We fit β\beta-models to the emission, and estimate a hot halo mass within 50 kpc of 5×109M5\times10^9 M_{\odot}. When this profile is extrapolated to 500 kpc (the approximate virial radius), the implied hot halo mass is 13×1011M1-3\times10^{11} M_{\odot}. These mass estimates assume a gas metallicity of Z=0.5ZZ = 0.5 Z_{\odot}. This galaxy's hot halo is a large reservoir of gas, but falls significantly below observational upper limits set by pervious searches, and suggests that NGC 1961 is missing 75% of its baryons relative to the cosmic mean, which would tentatively place it below an extrapolation of the baryon Tully-Fisher relationship of less massive galaxies. The cooling rate of the gas is no more than 0.4 MM_{\odot}/year, more than an order of magnitude below the gas consumption rate through star formation. We discuss the implications of this halo for galaxy formation models.Comment: 26 pages, 5 figures, accepted to ApJ. Updated to include journal ref and small changes added in proof

    Harmonization and standardization of data for a pan-European cohort on SARS- CoV-2 pandemic

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    The European project ORCHESTRA intends to create a new pan-European cohort to rapidly advance the knowledge of the effects and treatment of COVID-19. Establishing processes that facilitate the merging of heterogeneous clusters of retrospective data was an essential challenge. In addition, data from new ORCHESTRA prospective studies have to be compatible with earlier collected information to be efficiently combined. In this article, we describe how we utilized and contributed to existing standard terminologies to create consistent semantic representation of over 2500 COVID-19-related variables taken from three ORCHESTRA studies. The goal is to enable the semantic interoperability of data within the existing project studies and to create a common basis of standardized elements available for the design of new COVID-19 studies. We also identified 743 variables that were commonly used in two of the three prospective ORCHESTRA studies and can therefore be directly combined for analysis purposes. Additionally, we actively contributed to global interoperability by submitting new concept requests to the terminology Standards Development Organizations
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