762 research outputs found

    Introduction of exogenous AMF species alters the biological diversity and functionality of AMF communities associated with cowpea

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    The salinity in arid and semi-arid areas of the world is rapidly expanding due to climate change and anthropogenic activities. The use of inoculants containing beneficial microbes (e.g. arbuscular mycorrhizal fungi (AMF) and rhizobia) is a promising alternative to improve plant production in these regions. Here, we investigated the effect of common agricultural practices such as the use of beneficial microbes as inoculum and crop rotation on cowpea growth and on its association with soil microbes under non- and salt-stressed conditions. Plant experiments were carried out using non-sterilized soil (supplemented or not with NaCl) under greenhouse conditions. Bradyrhizobium yuanmingense BR 3267 strain and a commercial mixture of AMF (Endoplant Riego) were used as inoculants. In parallel, we assessed cowpea growth following succession of buffelgrass (Cenchrus ciliaris) with or without prior soil disturbance. Plant and symbiotic parameters, nutrient content in leaves and AMF and root nodule communities through DNA metabarcoding were evaluated. Under non-stressed conditions, inoculation with AMF and/or BR 3267 strain led to significant increase of cowpea biomass production and higher N or P content in leaves. The imposed saline condition affected the cowpea growth although without significantly affecting the symbiotic parameters. Moreover, the increase of AMF propagules available in the soil at buffelgrass sowing through the inoculation of commercial AMF was a determining factor to mitigate the effects of soil tillage and salinity on cowpea growth. The bacterial communities in the root nodules were affected by AMF communities rather by rhizobia inoculation. Benefits of commercial AMF could be explained by changes in the biological and functionality of the AMF communities associated with cowpea. This study reveals that microbial inoculation and crop rotation are effective practices for improvement of cowpea growth and on mitigating the harmful effects of salt

    Mortality of Patients with Hematological Malignancy after Admission to the Intensive Care Unit

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    Background: The admission of patients with malignancies to an intensive care unit (ICU) still remains a matter of substantial controversy. The identification of factors that potentially influence the patient outcome can help ICU professionals make appropriate decisions. Patients and Methods: 90 adult patients with hematological malignancy (leukemia 47.8%, high-grade lymphoma 50%) admitted to the ICU were analyzed retrospectively in this single-center study considering numerous variables with regard to their influence on ICU and day-100 mortality. Results: The median simplified acute physiology score (SAPS) II at ICU admission was 55 (ICU survivors 47 vs. 60.5 for non-survivors). The overall ICU mortality rate was 45.6%. With multivariate regression analysis, patients admitted with sepsis and acute respiratory failure had a significantly increased ICU mortality (sepsis odds ratio (OR) 9.12, 95% confidence interval (CI) 1.1-99.7, p = 0.04; respiratory failure OR 13.72, 95% CI 1.39-136.15, p = 0.025). Additional factors associated with an increased mortality were: high doses of catecholamines (ICU: OR 7.37, p = 0.005; day 100: hazard ratio (HR) 2.96, p < 0.0001), renal replacement therapy (day 100: HR 1.93, p = 0.026), and high SAPS II (ICU: HR 1.05, p = 0.038; day 100: HR 1.2, p = 0.027). Conclusion: The decision for or against ICU admission of patients with hematological diseases should become increasingly independent of the underlying malignant disease

    Exploring the spectroscopic diversity of type Ia supernovae with DRACULA: a machine learning approach

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    The existence of multiple subclasses of type Ia supernovae (SNeIa) has been the subject of great debate in the last decade. One major challenge inevitably met when trying to infer the existence of one or more subclasses is the time consuming, and subjective, process of subclass definition. In this work, we show how machine learning tools facilitate the automatic discovery of sub-populations of SNIa; to that end we introduce the DRACULA Python package (Dimensionality Reduction And Clustering for Unsupervised Learning in Astronomy). Our approach is divided in three steps: (i) Transfer Learning, which takes advantage of all available spectra (even those without an epoch estimate) as an information source, (ii) dimensionality reduction through Deep Learning and (iii) unsupervised learning (clustering) using K-Means. Results match a previously suggested classification scheme, showing that the proposed method is able to grasp the main spectral features behind the definition of such subclasses. Moreover, our methodology is capable of automatically identifying a hierarchical structure of spectral features. This allows the confirmation of the velocity of lines as a first order effect in the determination of SNIa sub-classes, followed by 91bg-like events. In this context, SNIa spectra are described by a space of 4 dimensions + 1 for the time evolution of objects. We interpreted this as evidence that the progenitor system and the explosion mechanism should be described by a small number of initial physical parameters. Given the expected data deluge in the forthcoming years, our proposed approach is essential to allow a quick and statistically coherent identification of subclasses (and outliers). DRACULA is publicly available within COINtoolbox (https://github.com/COINtoolbox/DRACULA)

    Dupla inoculação (rizóbio e fungos micorrízicos arbusculares) mitigam efeitos nocivos da salinidade no crescimento do feijão-caupi

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    A salinidade em áreas áridas e semiáridas do mundo está a expandir rapidamente devido às alterações climáticas e atividades humanas. O uso de inóculos contendo microrganismos benéficos, como fungos micorrízicos arbusculares (FMA) e bactérias simbióticas fixadoras de azoto, aliado ao manejo adequado do solo e das culturas, é uma alternativa promissora para melhorar a produção vegetal nessas regiões. Aqui, investigámos o efeito de práticas agrícolas comuns, nomeadamente a utilização de microrganismos benéficos como inóculo e a perturbação do solo entre a rotação de culturas, no crescimento do feijão-caupi e na sua associação com micróbios do solo sob condições salinas e não salinas. A estirpe Bradyrhizobium yuanmingense BR 3267, e uma mistura comercial de FMA (Endoplant Riego) foram utilizados como inóculos. Paralelamente, avaliámos o crescimento do feijão-caupi, após sucessão ao capim-buffel com ou sem perturbação prévia do solo. Ensaios de plantas em solo não-esterilizado (suplementado ou não com NaCl) foram realizados em dois ciclos de 75 dias em estufa. Parâmetros vegetais e simbióticos e o teor de nutrientes nas folhas foram determinados, bem como a diversidade bacteriana e de FMA em raízes e nódulos de feijão-caupi por meio de sequenciamento DNA metabarcode. Os nossos dados revelaram que os parâmetros simbióticos (número de nódulos e/ou taxa de colonização) foram melhorados no feijão-caupi inoculado com Bradyrhizobium e/ou FMA comercial, o que consequentemente resultou em maior teor de N ou P nas folhas. A salinidade imposta afetou negativamente o crescimento do feijão, porém sem afetar significativamente os parâmetros simbióticos analisados. O aumento de propágulos de FMA disponíveis no solo através da inoculação de FMA comercial foi um fator determinante para mitigar os efeitos do manejo do solo no crescimento do feijão. A perturbação do solo mostrou impacto negativo nos parâmetros vegetais e simbióticos, exceto para o número de nódulos. Além disso, os efeitos positivos do uso de FMA comercial no crescimento do feijão-caupi, em condições controlo ou de salinidade podem ser explicados pelas mudanças na funcionalidade das comunidades de FMA associadas ao feijão-caupi. Por outro lado, as comunidades bacterianas em nódulos ou raízes do feijão não foram afetadas pela inoculação de FMA ou de rizóbios. Este estudo revela que a dupla inoculação (mistura de rizóbio e FMA) e a rotação de culturas, sem a perturbação do solo, são práticas eficazes para melhorar o crescimento do feijão-caupi e mitigar os efeitos nocivos do sal no seu crescimento. Mais, estes resultados também sugerem que os efeitos sinérgicos entre rizóbios e FMA dependem principalmente de um estabelecimento bem-sucedido da simbiose entre FMA e a planta hospedeira e não da comunidade de FMA em si

    A Discrete Event Simulation model to evaluate the treatment pathways of patients with Cataract in the United Kingdom

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    Background The number of people affected by cataract in the United Kingdom (UK) is growing rapidly due to ageing population. As the only way to treat cataract is through surgery, there is a high demand for this type of surgery and figures indicate that it is the most performed type of surgery in the UK. The National Health Service (NHS), which provides free of charge care in the UK, is under huge financial pressure due to budget austerity in the last decade. As the number of people affected by the disease is expected to grow significantly in coming years, the aim of this study is to evaluate whether the introduction of new processes and medical technologies will enable cataract services to cope with the demand within the NHS funding constraints. Methods We developed a Discrete Event Simulation model representing the cataract services pathways at Leicester Royal Infirmary Hospital. The model was inputted with data from national and local sources as well as from a surgery demand forecasting model developed in the study. The model was verified and validated with the participation of the cataract services clinical and management teams. Results Four scenarios involving increased number of surgeries per half-day surgery theatre slot were simulated. Results indicate that the total number of surgeries per year could be increased by 40% at no extra cost. However, the rate of improvement decreases for increased number of surgeries per half-day surgery theatre slot due to a higher number of cancelled surgeries. Productivity is expected to improve as the total number of doctors and nurses hours will increase by 5 and 12% respectively. However, non-human resources such as pre-surgery rooms and post-surgery recovery chairs are under-utilized across all scenarios. Conclusions Using new processes and medical technologies for cataract surgery is a promising way to deal with the expected higher demand especially as this could be achieved with limited impact on costs. Non-human resources capacity need to be evenly levelled across the surgery pathway to improve their utilisation. The performance of cataract services could be improved by better communication with and proactive management of patients.Peer reviewedFinal Published versio
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