2,101 research outputs found

    Early diagnosis of pancreatic cancer: What strategies to avoid a foretold catastrophe

    Get PDF
    While great strides in improving survival rates have been made for most cancers in recent years, pancreatic ductal adenocarcinoma (PDAC) remains one of the solid tumors with the worst prognosis. PDAC mortality often overlaps with incidence. Surgical resection is the only potentially curative treatment, but it can be performed in a very limited number of cases. In order to improve the prognosis of PDAC, there are ideally two possible ways: the discovery of new strategies or drugs that will make it possible to treat the tumor more successfully or an earlier diagnosis that will allow patients to be operated on at a less advanced stage. The aim of this review was to summarize all the possible strategies available today for the early diagnosis of PDAC and the paths that research needs to take to make this goal ever closer. All the most recent studies on risk factors and screening modalities, new laboratory tests including liquid biopsy, new imaging methods and possible applications of artificial intelligence and machine learning were reviewed and commented on. Unfortunately, in 2022 the results for this type of cancer still remain discouraging, while a catastrophic increase in cases is expected in the coming years. The article was also written with the aim of highlighting the urgency of devoting more attention and resources to this pathology in order to reach a solution that seems more and more unreachable every day

    Growth and energy quality of eucalyptus wood in different crop-livestock-forest spatial arrangements.

    Get PDF
    Crescimento e qualidade energética da madeira do eucalipto em diferentesarranjos de integração lavoura-pecuária-floresta.O objetivo do trabalho foi avaliar o crescimento e a qualidade energética da madeira de materiais genéticos de eucalipto em diferentes arranjos espaciais de plantio em sistema de integração lavoura-pecuária-floresta em Barra-do-Garças (MT). Foram avaliados cinco materiais genéticos de Eucalyptus spp em oito arranjos de plantio aos 76 meses de idade. As características avaliadas foram o crescimento em diâmetro, altura, volume, mortalidade, produção de massa seca, relação cerne e alburno, fator de forma, volume de casca, densidade básica, poder calorífico superior, teor de cinzas, voláteis, carbono fixo e energia no tronco. Os dados foram avaliados através do ajuste de uma função de crescimento, teste de identidade de modelos e ANOVA, com comparações de médias por Scott-Knott. Os clones de híbridos de Eucalyptus grandis x Eucalyptus urophylla apresentaram melhor desempenho para a produção de energia na região de Barra-do-Garça (MT), o que se deveu a maior produtividade volumétrica que foi determinante na estimativa de energia disponível por árvore e área plantada.O crescimento, a forma do tronco e a densidade básica variaram entre e dentro de um mesmo material genético em função do arranjo espacial de plantio.O mesmo não ocorreu com as propriedades energéticas da madeira como o poder calorífico superior, o teor de cinzas, carbono fixo e voláteis. Palavras-chave: Curva de crescimento, densidade básica, poder calorífico, agrofloresta, Brasil. Abstract: The aim of the present study was to assess the growth and energetic properties of genetic material of eucalyptus grown in several integrated crop-livestock system spatial arrangements in Barra-do-Garças City (MT). The genetic material of 76-month old Eucalyptus spp from eight spatial arrangements were assessed according to the following properties: diameter, height and volume growth, mortality rate, dry matter yield, sapwood to heartwood ratio, form factor, bark volume, basic density, superior calorific value, ash content, volatile matter, fixed carbon and trunk energy. Data analysis was performed by adjusting growth function, test for model identity and parameters equalityand ANOVA tests to Scott-Knott?s mean clustering test. Eucalyptus grandisx E. urophyllaclones from recorded the highest energy efficiency due to their high yieldvolume, which was decisiveto determine estimated energy available per tree and cropland area. Growth, stem shape and basic density varied among,and within,the same genetic materials, depending ontheir respective spatial arrangement. However, solid biomass properties (high calorific value, ash content, fixed carbon and volatile matter) remained stable.Keywords:Growth curve, basic density, calorific value, agroforestry, Brazil

    Benzamil inhibits neuronal and heterologously expressed small conductance Ca2²⁺-activated K⁺ channels

    Get PDF
    Small conductance Ca^{2+}-activated K^{+} (SK) channels are expressed throughout the soma and dendrites of pyramidal neurons in the neocortex and hippocampal formation, where they participate in the local regulation of membrane excitability and synaptic signals. Through their inter-play with Ca^{2+} channels, SK channels regulate Ca^{2+} influx triggered by back-propagating action potentials in dendrites. Inhibition of SK channels affects both the amplitude and duration of Ca^{2+} transients, but the role of Ca^{2+} clearance mechanisms and their link to SK channel activity has not been established. Here we report the effect of the Na^{+}/Ca^{2+} exchanger (NCX) inhibitor benzamil on Ca^{2+} extrusion and SK channels in the regulation of dendritic Ca^{2+} signals. Benzamil increased the duration and amplitude of dendritic Ca^{2+} transients elicited by back-propagating action potentials in hippocampal pyramidal neurons. This data is consistent with previous studies with SK channel blockers and suggests that benzamil inhibits SK channels in addition to the Na^{+}/Ca^{2+} exchanger. Here we show that indeed both the neuronal SK-mediated IAHP current and the currents mediated by heterologously expressed SK channels were inhibited by benzamil. The inhibition of recombinant SK channels was seen with different K+ concentration gradients, and was stronger at negative voltages. The suppression of SK channels by benzamil is consistent with previous findings on the modulation of Ca^{2+} signals by SK channels in neurons. We additionally show that benzamil inhibits neuronal voltage-gated calcium currents. The results prompt a careful reassessment of the effects of benzamil on Ca^{2+} transients in native systems, given the spectrum of ion channels and exchangers this compound targets within a similar range of concentrations

    Economic benefit and social impact derived by a food loss prevention strategy in the vegetable sector: A spatial and temporal analysis at the regional level

    Get PDF
    Introduction: Reduction of food loss in the horticultural sector is critical to simultaneously support the transition toward a diet with higher consumption of vegetables and the achievement of policy goals aimed at halving the quantity of wastage by 2030. However, the lack of precise information and the presence of múltiple interconnected factors makes it difficult to assess the potential socioeconòmic benefits and therefore the decision-making process of food loss reduction strategies. Methods: A case study approach has been used to assess the econòmic loss and nutrional impact of food loss in the horticulture primary production. The selection of the main vegetable products was based on an historical series while econòmic and nutritional impact were estimated starting from national and European indicator. Results: The food loss correspond to 26% of the total production and 14% of the total agricultural production econòmic value. The social analysis confirm the possibility of redistributing food loss among the population even in the most critical months and areas. Discussion: The combination of social and econòmic indicator resulted essential to provide key information at the decision-making level to pave the way for the elaboration of short- and long-term food loss reduction strategies. Indeed, no single-bullet strategy can be applied to overcome the problem of food loss as many actor with different needs are involved

    Site selection for dendroclimatological studies with Bertholletia excelsa.

    Get PDF
    Edição dos abstracts do 24º IUFRO World Congress, 2014, Salt Lake City. Sustaining forests, sustaining people: the role of research

    Semi-Analytic Galaxy Evolution (SAGE): Model Calibration and Basic Results

    Full text link
    This paper describes a new publicly available codebase for modelling galaxy formation in a cosmological context, the "Semi-Analytic Galaxy Evolution" model, or SAGE for short. SAGE is a significant update to that used in Croton et al. (2006) and has been rebuilt to be modular and customisable. The model will run on any N-body simulation whose trees are organised in a supported format and contain a minimum set of basic halo properties. In this work we present the baryonic prescriptions implemented in SAGE to describe the formation and evolution of galaxies, and their calibration for three N-body simulations: Millennium, Bolshoi, and GiggleZ. Updated physics include: gas accretion, ejection due to feedback, and reincorporation via the galactic fountain; a new gas cooling--radio mode active galactic nucleus (AGN) heating cycle; AGN feedback in the quasar mode; a new treatment of gas in satellite galaxies; and galaxy mergers, disruption, and the build-up of intra-cluster stars. Throughout, we show the results of a common default parameterization on each simulation, with a focus on the local galaxy population.Comment: 15 pages, 9 figures, accepted for publication in ApJS. SAGE is a publicly available codebase for modelling galaxy formation in a cosmological context, available at https://github.com/darrencroton/sage Questions and comments can be sent to Darren Croton: [email protected]

    Measuring the Spin of Spiral Galaxies

    Get PDF
    We compute the angular momentum, the spin parameter and the related distribution function for Dark Matter halos hosting a spiral galaxy. We base on scaling laws, inferred from observations, that link the properties of the galaxy to those of the host halo; we further assume that the Dark Matter has the same total specific angular momentum of the baryons. Our main results are: (i) we find that the gas component of the disk significantly contributes to the total angular momentum of the system; (ii) by adopting for the Dark Matter the observationally supported Burkert profile, we compute the total angular momentum of the disk and its correlation with the rotation velocity; (iii) we find that the distribution function of the spin parameter λ\lambda peaks at a value of about 0.03, consistent with a no-major-merger scenario for the late evolution of spiral galaxies.Comment: 4 pages, 2 figures. Minor changes. Accepted on ApJ

    Repeatability of fruits and seeds production and selection of Brazil nut genotypes in native populations in Roraima.

    Get PDF
    This study estimates the repeatability coefficients of two production traits in two native populations of Brazil nut trees. It determines the number of years of suitable evaluations for an efficient selection process, determines the permanent phenotypic correlation between production traits and also the selection of promising trees in these populations. Populations, located in the Itã region (ITA) and in the in the Cujubim region (CUJ), are both belonging to the municipality of Caracaraí, state of Roraima - Brazil, and consist of 85 and 51 adult trees, respectively. Each tree was evaluated regarding the number of fruits per plant (NFP) and fresh seed weight per plant (SWP), for eight (ITA) and five consecutive years (CUJ). Statistical analyses were performed according to the mixed model methodology, using Software Selegen-REML/BLUP (RESENDE, 2007). The repeatability coefficients were low for NFP (0.3145 and 0.3269 for ITA and CUJ, respectively) and also for SWP (0.2957 and 0.3436 for ITA and CUJ, respectively). It on average takes nine evaluation years to reach coefficients of determination higher than 80%. Permanent phenotypic correlation values higher than 0.95 were obtained for NFP and SWP in both populations. Although trees with a high number of fruits and seed weight were identified, more evaluation years are needed to perform the selection process more efficiently
    corecore