274 research outputs found

    Improving the description of the suspended particulate matter concentrations in the southern North Sea through assimilating remotely sensed data

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    The integration of remote sensing data of suspended particulate matter (SPM) into numerical models is useful to improve the understanding of the temporal and spatial behaviour of SPM in dynamic shelf seas. In this paper a generic method based on the Ensemble Kalman Filtering (EnKF) for assimilating remote sensing SPM data into a transport model is presented. The EnKF technique is used to assimilate SPM data of the North Sea retrieved from the MERIS sensor, into the computational water quality and sediment transport model, Delft3D-WAQ. The satellite data were processed with the HYDROPT algorithm that provides SPM concentrations and error information per pixel, which enables their use in data assimilation. The uncertainty of the transport model, expressed in the system noise covariance matrix, was quantified by means of a Monte Carlo approach. From a case study covering the first half of 2003, it is demonstrated that the MERIS observations and transport model application are sufficiently robust for a successful generic assimilation. The assimilation results provide a consistent description of the spatial-temporal variability of SPM in the southern North Sea and show a clear decrease of the model bias with respect to independent in-situ observations. This study also identifies some shortcomings in the assimilated results, such as over prediction of surface SPM concentrations in regions experiencing periods of rapid stratification/de-stratification. Overall this feasibility study leads to a range of suggestions for improving and enhancing the model, the observations and the assimilation scheme. © 2011 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Netherlands

    Instructional multimedia: An investigation of student and instructor attitudes and student study behavior

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    <p>Abstract</p> <p>Background</p> <p>Educators in allied health and medical education programs utilize instructional multimedia to facilitate psychomotor skill acquisition in students. This study examines the effects of instructional multimedia on student and instructor attitudes and student study behavior.</p> <p>Methods</p> <p>Subjects consisted of 45 student physical therapists from two universities. Two skill sets were taught during the course of the study. Skill set one consisted of knee examination techniques and skill set two consisted of ankle/foot examination techniques. For each skill set, subjects were randomly assigned to either a control group or an experimental group. The control group was taught with live demonstration of the examination skills, while the experimental group was taught using multimedia. A cross-over design was utilized so that subjects in the control group for skill set one served as the experimental group for skill set two, and vice versa. During the last week of the study, students and instructors completed written questionnaires to assess attitude toward teaching methods, and students answered questions regarding study behavior.</p> <p>Results</p> <p>There were no differences between the two instructional groups in attitudes, but students in the experimental group for skill set two reported greater study time alone compared to other groups.</p> <p>Conclusions</p> <p>Multimedia provides an efficient method to teach psychomotor skills to students entering the health professions. Both students and instructors identified advantages and disadvantages for both instructional techniques. Reponses relative to instructional multimedia emphasized efficiency, processing level, autonomy, and detail of instruction compared to live presentation. Students and instructors identified conflicting views of instructional detail and control of the content.</p

    Development and validation of a method for precise dating of female puberty in laboratory rodents: The puberty ovarian maturation score (Pub-Score)

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    Puberty is a key developmental event whose primary regulatory mechanisms remain poorly understood. Precise dating of puberty is crucial for experimental (preclinical) studies on its complex neuroendocrine controlling networks. In female laboratory rodents, external signs of puberty, such as vaginal opening (VO) and epithelial cell cornification (i.e., first vaginal estrus, FE), are indirectly related to the maturational state of the ovary and first ovulation, which is the unequivocal marker of puberty. Whereas in rats, VO and FE are almost simultaneous with the first ovulation, these events are not so closely associated in mice. Moreover, external signs of puberty can be uncoupled with first ovulation in both species under certain experimental conditions. We propose herein the Pubertal Ovarian Maturation Score (Pub-score), as novel, reliable method to assess peripubertal ovarian maturation in rats and mice. This method is founded on histological evaluation of pre-pubertal ovarian maturation, based on antral follicle development, and the precise timing of first ovulation, by retrospective dating of maturational and regressive changes in corpora lutea. This approach allows exact timing of puberty within a time-window of at least two weeks after VO in both species, thus facilitating the identification and precise dating of advanced or delayed puberty under various experimental conditions

    Влияние молекулярно-генетического профиля менингиом на течение заболевания и рецидивирование при использовании комбинированного метода лечения

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    Introduction. Meningioma is one of the most common central nervous system tumors, accounting for 39.7 % of all primary brain tumors. The tumor originates from arachnoid meningothelial cells and is characterized by a wide range of histological types classified into 15 subtypes. The histological classification of meningiomas allows us to predict meningioma behavior and the risk of disease recurrence, as well as to define treatment strategies. However, clinical outcomes in histological subgroups of patients are often inconsistent with the histological grade of malignancy. Thus, a more reliable method is needed both to determine the histological subtype of the tumor and to predict the clinical course of the disease with the potential for targeted treatment.The purpose of the study was to summarize the available data on the effect of results of the genomic and proteomic tumor analysis on carcinogenesis with the relationship between the mutational changes and noninvasive diagnosis, treatment and the course of the disease.Material and Methods. Literature search was carried out in the PubMed, Elibrary system, publications were included mainly from 2010 to 2023. with the identification of articles by the keyword “genetic analysis of meningiomas” and synonyms. 550 articles were found, of which 55 were used to write a literature review.Conclusion. The study of the molecular genetic profile of meningiomas will improve the classification and establish a correlation with MRI data, the course of the disease and prognosis.Введение. Менингиома, одна из самых распространенных опухолей центральной нервной системы, составляет 39,7 % всех выявляемых первичных опухолей головного мозга. Источником возникновения этих новообразований являются менинготелиальные клетки паутинной оболочки. Менингиомы отличаются широким спектром гистологических вариантов, что выражается в наличии 15 гистоподтипов. Гистологическая классификация менингиом позволяет предположить дальнейшее развитие заболевания, спрогнозировать риски рецидива опухоли, определить тактику ведения пациента. Однако клинические исходы в гистологических подгруппах пациентов часто противоречат гистологической градации злокачественности. Таким образом, необходим более надежный метод как для определения гистологического подтипа опухоли, так и для прогнозирования клинического течения заболевания с потенциалом для таргетного лечения.Цель исследования – обобщить литературные данные о влиянии результата геномного и протеомного анализа опухоли на канцерогенез с определением взаимосвязи данных мутационных изменений с неинвазивной диагностикой, лечением и течением заболевания.Материал и методы. Поиск литературы производился в системе PubMed, Elibrary, включались публикации преимущественно с 2010 по 2023 г. с идентификацией статей по ключевому слову «генетический анализ менингиом» и синонимами. Найдено 550 источников, из которых 55 использовано для написания литературного обзора. Ряд статей, опубликованных ранее 2010 г., использованы для исторической справки о методах лечения и диагностики. Данные статьи не включали информацию о генетическом аспекте публикации.Заключение. Продолжение изучения молекулярно-генетического профиля менингиом, в том числе, возможно, измененного под воздействием комплексного лечения, позволит усовершенствовать классификацию и определить корреляционную зависимость между морфологическим, молекулярно-генетическим профилем опухоли, структурой менингиомы на основе анализа данных МРТ и клиническим течением заболевания

    Prostaglandin F2-alpha receptor (FPr) expression on porcine corpus luteum microvascular endothelial cells (pCL-MVECs)

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    <p>Abstract</p> <p>Background</p> <p>The corpus luteum (CL) is a transient endocrine gland and prostaglandin F2-alpha is considered to be the principal luteolysin in pigs. In this species, the in vivo administration of prostaglandin F2-alpha induces apoptosis in large vessels as early as 6 hours after administration. The presence of the prostaglandin F2-alpha receptor (FPr) on the microvascular endothelial cells (pCL-MVECs) of the porcine corpus luteum has not yet been defined. The aim of the study was to assess FPr expression in pCL-MVECs in the early and mid-luteal phases (EL-p, ML-p), and during pregnancy (P-p). Moreover, the effectiveness of prostaglandin F2-alpha treatment in inducing pCL-MVEC apoptosis was tested.</p> <p>Methods</p> <p>Porcine CLs were collected in the EL and ML phases and during P-p. All CLs from each animal were minced together and the homogenates underwent enzymatic digestion. The pCL-MVECs were then positively selected by an immunomagnetic separation protocol using Dynabeads coated with anti-CD31 monoclonal antibody and seeded in flasks in the presence of EGM 2-MV (Microvascular Endothelial Cell Medium-2). After 4 days of culture, the cells underwent additional immunomagnetic selection and were seeded in flasks until the confluent stage.</p> <p>PCR Real time, western blot and immunodetection assays were utilized to assess the presence of FPr on pCL-MVEC primary cultures. Furthermore, the influence of culture time (freshly isolated, cultured overnight and at confluence) and hormonal treatment (P4 and E2) on FPr expression in pCL-MVECs was also investigated. Apoptosis was detected by TUNEL assay of pCL-MVECs exposed to prostaglandin F2-alpha.</p> <p>Results</p> <p>We obtained primary cultures of pCL-MVECs from all animals. FPr mRNA and protein levels showed the highest value (ANOVA) in CL-MVECs derived from the early-luteal phase. Moreover, freshly isolated MVECs showed a higher FPr mRNA value than those cultured overnight and confluent cells (ANOVA). prostaglandin F2-alpha treatment failed to induce an apoptotic response in all the pCL-MVEC cultures.</p> <p>Conclusion</p> <p>Our data showing the presence of FPr on MVECs and the inability of prostaglandin F2-alpha to evoke an in vitro apoptotic response suggest that other molecules or mechanisms must be considered in order to explain the in vivo direct pro-apoptotic effect of prostaglandin F2-alpha at the endothelial level.</p

    Illegal Immigration, Deportation Policy, and the Optimal Timing of Return

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    Countries with strict immigration policies often resort to deportation measures to reduce their stocks of illegal immigrants. Many of their undocumented foreign workers, however, are not deported but rather choose to return home voluntarily. This paper studies the optimizing behavior of undocumented immigrants who continuously face the risk of deportation, modeled by a stochastic process, and must decide how long to remain in the host country. It is found that the presence of uncertainty with respect to the length of stay abroad unambiguously reduces the desired migration duration and may trigger a voluntary return when a permanent stay would otherwise be optimal. Voluntary return is motivated by both economic and psychological factors. Calibration of the model to match the evidence on undocumented Thai migrants in Japan suggests that the psychological impact of being abroad as an illegal alien may be equivalent to as large as a 68% cut in the consumption rate at the point of return
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