195 research outputs found

    Анализ и моделирование макроэкономических процессов в переходной период

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    Рассматривается построение моделей процессов инфляции и трансформирования отношений собственности. На основании разработанных моделей поставлены задачи оптимального управления данными процессами, для решения которых применяется метод динамического моделирования. Получены аналитические выражения для оптимальных управляющих воздействий и оптимальные траектории реализации процессов инфляции и трансформирования отношений собственности.У статті розглядається побудова моделей процесів інфляції і трансформування власності. На підставі розроблених моделей поставлені задачі оптимального керування даними процесами, для рішення яких застосовується метод динамічного моделювання. Отримані аналітичні співвідношення для оптимальних керуючих впливів і оптимальні траєкторії реалізації процесів інфляції і трансформування власності.The paper is devoted to construction of mathematical models for inflation and transforming the property form or privatization. The models constructed are used for the optimal control problem statement aiming to compute optimal trajectories for the processes implementation. To solve the optimal control problem dynamic programming method is applied. As a result of the problem solving analytical expressions were derived for optimal inputs, and respective optimal trajectories were computed for various initial conditions

    V.I. Vernadsky and the noosphere concept: Russian understandings of society-nature interaction

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    Recent Russian legislative and policy documentation concerning national progress towards sustainable development has suggested that the attainment of such a state would represent the first stage in the development of the noosphere as outlined by the Russian scientist Vladimir Ivanovich Vernadsky (1863–1945). This paper explores Vernadsky’s model of evolutionary change through a focus on his work on the biosphere and noosphere in an attempt to further understanding of the way in which Russia is approaching the concept of sustainable development in the contemporary period. It is argued that the official Russian interpretation of the noosphere idea tends to obscure the evolutionary and materialist foundations of Vernadsky’s biosphere–noosphere conceptualisation. At the same time, the concluding section of the paper suggests that the scope of Vernadsky’s work can be used to stimulate the search for a more coherent approach to work in areas of sustainable development and sustainability across the span of the social and physical sciences

    Functional and evolutionary consequences of cranial fenestration in birds

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    Ostrich-like birds (Palaeognathae) show very little taxonomic diversity while their sister taxon (Neognathae) contains roughly 10,000 species. The main anatomical differences between the two taxa are in the crania. Palaeognaths lack an element in the bill called the lateral bar that is present in both ancestral theropods and modern neognaths, and have thin zones in the bones of the bill, and robust bony elements on the ventral surface of their crania. Here we use a combination of modeling and developmental experiments to investigate the processes that might have led to these differences. Engineering-based finite element analyses indicate that removing the lateral bars from a neognath increases mechanical stress in the upper bill and the ventral elements of the skull, regions that are either more robust or more flexible in palaeognaths. Surgically removing the lateral bar from neognath hatchlings led to similar changes. These results indicate that the lateral bar is load-bearing and suggest that this function was transferred to other bony elements when it was lost in palaeognaths. It is possible that the loss of the load-bearing lateral bar might have constrained diversification of skull morphology in palaeognaths and thus limited taxonomic diversity within the group. This is the peer reviewed version of the following article: Gussekloo, S. W., Berthaume, M. A., Pulaski, D. R., Westbroek, I. , Waarsing, J. H., Heinen, R. , Grosse, I. R. and Dumont, E. R. (2017), Functional and evolutionary consequences of cranial fenestration in birds. Evolution, 71: 1327-1338., which has been published in final form at 10.1111/evo.13210. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions

    Agammaglobulinaemia despite terminal B-cell differentiation in a patient with a novel LRBA mutation

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    Mutations in lipopolysaccharide-responsive vesicle trafficking, beach and anchor-containing protein (LRBA) cause immune deficiency and inflammation. Here, we are reporting a novel homozygous mutation in LRBA allele in 7-year-old Omani boy, born to consanguineous parents. He presented with type 1 diabetes, autoimmune haematological cytopenia, recurrent chest infections and lymphocytic interstitial lung disease. The patient was treated with CTLA4-Ig (abatacept) with good outcome every 2 weeks for a period of 3 months. He developed complete IgG deficiency, but remarkably, histological examination revealed germinal centres and plasma cells in lymphoid and inflamed lung tissue. Further charatecterisation showed these cells to express IgM but not IgG. This ex vivo analysis suggests that LRBA mutation confers a defect in class switching despite plasma cell formation

    Incidental durotomy: predictive risk model and external validation of natural language process identification algorithm

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    OBJECTIVE Incidental durotomy is a common complication of elective lumbar spine surgery seen in up to 11% of cases. Prior studies have suggested patient age and body habitus along with a history of prior surgery as being associated with an increased risk of dural tear. To date, no calculator has been developed for quantifying risk. Here, the authors' aim was to identify independent predictors of incidental durotomy, present a novel predictive calculator, and externally validate a novel method to identify incidental durotomies using natural language processing (NLP).METHODS The authors retrospectively reviewed all patients who underwent elective lumbar spine procedures at a tertiary academic hospital for degenerative pathologies between July 2016 and November 2018. Data were collected regarding surgical details, patient demographic information, and patient medical comorbidities. The primary outcome was incidental durotomy, which was identified both through manual extraction and the NLP algorithm. Multivariable logistic regression was used to identify independent predictors of incidental durotomy. Bootstrapping was then employed to estimate optimism in the model, which was corrected for; this model was converted to a calculator and deployed online.RESULTS Of the 1279 elective lumbar surgery patients included in this study, incidental durotomy occurred in 108 (8.4%). Risk factors for incidental durotomy on multivariable logistic regression were increased surgical duration, older age, revision versus index surgery, and case starts after 4 PM. This model had an area under curve (AUC) of 0.73 in predicting incidental durotomies. The previously established NLP method was used to identify cases of incidental durotomy, of which it demonstrated excellent discrimination (AUC 0.97).CONCLUSIONS Using multivariable analysis, the authors found that increased surgical duration, older patient age, cases started after 4 PM, and a history of prior spine surgery are all independent positive predictors of incidental durotomy in patients undergoing elective lumbar surgery. Additionally, the authors put forth the first version of a clinical calculator for durotomy risk that could be used prospectively by spine surgeons when counseling patients about their surgical risk. Lastly, the authors presented an external validation of an NLP algorithm used to identify incidental durotomies through the review of free-text operative notes. The authors believe that these tools can aid clinicians and researchers in their efforts to prevent this costly complication in spine surgery
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