268 research outputs found

    Comparative Analysis of Nuclear Transfer Embryo Derived Mouse Embryonic Stem Cells. Part I: Cellular characterization

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    Embryonic stem cells derived from nuclear transfer embryos (ntESCs) are particularly valuable for regenerative medicine, as they are a patient-specific and histocompatible cell source for the treatment of varying diseases. However, currently, little is known about their cellular and molecular profile. In the present study, in a mouse model different donor cell-derived ntESCs from various genetic backgrounds were compared with reference ESCs and analyzed comprehensively at the cellular level. A number of pluripotency marker genes were compared by flow cytometry and immunocytochemistry analysis. Significant differences at the protein level were observed for POU5F1, SOX2, FGF4, NANOG, and SSEA-1. However, such differences had no effect on in vitro cell differentiation and cell fate: derivatives of the three germ layers were detected in all ntESC lines. The neural and cardiac in vitro differentiation revealed minor differences between the cell lines, both at the mRNA and protein level. Karyotype analyses and cell growth studies did not reveal any significant variations. Despite some differences observed, the present study revealed that ntESC lines had similar differentiation competences compared to other ESCs. The results indicate that the observed differences may be related to the genotype rather than to the nuclear transfer technology

    Comparison of EKF and Neural Network based wing shape estimation of a flexible wing demonstrator

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    Structural flexibility of advanced, large-wingspan aircrafts is a crucial factor which has huge influence on the dynamics and stability of these vehicles. In case of a highly flexible wing structure, there is a need for an efficient observer to measure and predict the structural changes and dynamics of the wing. However, the modal coordinates of the wing cannot be measured directly so designing a state observer is necessary. Since the flexible aircraft model is nonlinear, the classical Kalman filter approach can have limited performance. Instead, two state observer approaches are investigated in the paper. First, we present a model-based method for designing an extended Kalman filter (EKF) when only a linear parameter-varying model (LPV) is available to describe the behaviour of the real aircraft. Second, we present a data-driven approach for this problem which is based on the new KalmanNet architecture. Finally, the results of the two methods are evaluated on the T-Flex model of the FLiPASED H2020 project

    Increased suicide risk among younger women in winter during full moon in northern Europe : an artifact or a novel finding?

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    Available evidence suggests that there is no effect of moon phases on suicidal behavior. However, a Finnish study recently reported elevated suicide rates during full-moon, but only among premenopausal women and only in winter. This could not be replicated in an Austrian study and stirred a discussion about whether the Finnish finding was false-positive or if there are unaccounted moderator variables differing between Finland and Austria. The goal of the present study was to provide another replication with data from Sweden, which is geographically more comparable to Finland than Austria. We also investigated the discussed moderator variables latitude and nightly artificial brightness. There were 48,537 suicides available for analysis. The fraction of suicides during the full-moon quarter in winter did not differ significantly from the expected 25% among premenopausal women (23.3%) and in the full sample (24.7%). The incidence risk ratios for full moon quarter in Poisson regression models were 0.96 (95% CI: 0.90-1.02) for premenopausal women and 1.01 (95% CI: 0.99-1.04) for the full sample. According to Bayes-factor analysis, the evidence supports the null-hypothesis (no association) over the alternative hypothesis (some association). We found similar results when we split the data by latitude and artificial nightly brightness, respectively. In line with the Austrian study, there was no increase of suicides in Sweden among premenopausal women in winter during full-moon. The results from the Finnish study are likely false positive, perhaps resulting from problematic but common research and publication practices, which we discuss

    Rapid interphase and metaphase assessment of specific chromosomal changes in neuroectodermal tumor cells by in situ hybridization with chemically modified DNA probes

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    Repeated DNAs from the constitutive heterochromatin of human chromosomes 1 and 18 were used as probes in nonradioactive in situ hybridization experiments to define specific numerical and structural chromosome aberrations in three human glioma cell lines and one neuroblastoma cell line. The number of spots detected in interphase nuclei of these tumor cell lines and in normal diploid nuclei correlated well with metaphase counts of chromosomes specifically labeled by in situ hybridization. Rapid and reliable assessments of aneuploid chromosome numbers in tumor lines in double hybridization experiments were achieved, and rare cells with bizarre phenotype and chromosome constitution could be evaluated in a given tumor cell population. Even with suboptimal or rare chromosome spreads specific chromosome aberrations were delineated. As more extensive probe sets become available this approach will become increasingly powerful for uncovering various genetic alterations and their progression in tumor cells

    Are Mental Health Effects of Internet Use Attributable to the Web-Based Content or Perceived Consequences of Usage? A Longitudinal Study of European Adolescents.

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    BACKGROUND: Adolescents and young adults are among the most frequent Internet users, and accumulating evidence suggests that their Internet behaviors might affect their mental health. Internet use may impact mental health because certain Web-based content could be distressing. It is also possible that excessive use, regardless of content, produces negative consequences, such as neglect of protective offline activities. OBJECTIVE: The objective of this study was to assess how mental health is associated with (1) the time spent on the Internet, (2) the time spent on different Web-based activities (social media use, gaming, gambling, pornography use, school work, newsreading, and targeted information searches), and (3) the perceived consequences of engaging in those activities. METHODS: A random sample of 2286 adolescents was recruited from state schools in Estonia, Hungary, Italy, Lithuania, Spain, Sweden, and the United Kingdom. Questionnaire data comprising Internet behaviors and mental health variables were collected and analyzed cross-sectionally and were followed up after 4 months. RESULTS: Cross-sectionally, both the time spent on the Internet and the relative time spent on various activities predicted mental health (P<.001), explaining 1.4% and 2.8% variance, respectively. However, the consequences of engaging in those activities were more important predictors, explaining 11.1% variance. Only Web-based gaming, gambling, and targeted searches had mental health effects that were not fully accounted for by perceived consequences. The longitudinal analyses showed that sleep loss due to Internet use (ss=.12, 95% CI=0.05-0.19, P=.001) and withdrawal (negative mood) when Internet could not be accessed (ss=.09, 95% CI=0.03-0.16, P<.01) were the only consequences that had a direct effect on mental health in the long term. Perceived positive consequences of Internet use did not seem to be associated with mental health at all. CONCLUSIONS: The magnitude of Internet use is negatively associated with mental health in general, but specific Web-based activities differ in how consistently, how much, and in what direction they affect mental health. Consequences of Internet use (especially sleep loss and withdrawal when Internet cannot be accessed) seem to predict mental health outcomes to a greater extent than the specific activities themselves. Interventions aimed at reducing the negative mental health effects of Internet use could target its negative consequences instead of the Internet use itself. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN): 65120704; http://www.isrctn.com/ISRCTN65120704?q=&filters=recruitmentCountry:Lithuania&sort =&offset= 5&totalResults=32&page=1&pageSize=10&searchType=basic-search (Archived by WebCite at http://www.webcitation/abcdefg)

    Distribution of chromosome 18 and X centric heterochromatin in the interphase nucleus of cultured human cells

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    In situ hybridization of human chromosome 18 and X-specific alphoid DNA-probes was performed in combination with three dimensional (3D) and two dimensional (2D) image analysis to study the interphase distribution of the centric heterochromatin (18c and Xc) of these chromosomes in cultured human cells. 3D analyses of 18c targets using confocal laser scanning microscopy indicated a nonrandom disposition in 73 amniotic fluid cell nuclei. The shape of these nuclei resembled rather flat cylinders or ellipsoids targets were preferentially arranged in a domain around the nuclear center, but close to or associated with the nuclear envelope. Within this domain, however, positionings of the two targets occurred independently from each other, i.e., the two targets were observed with similar frequencies at the same (upper or lower) side of the nuclear envelope as those on opposite sides. This result strongly argues against any permanent homologous association of 18c. A 2D analytical approach was used for the rapid evaluation of 18c positions in over 4000 interphase nuclei from normal male and female individuals, as well as individuals with trisomy 18 and Bloom's syndrome. In addition to epithelially derived amniotic fluid cells, investigated cell types included in vitro cultivated fibroblastoid cells established from fetal lung tissue and skin-derived fibroblasts. In agreement with the above 3D observations 18c targets were found significantly closer (P < 0.01) to the center of the 2D nuclear image (CNI) and to each other in all these cultures compared to a random distribution derived from corresponding ellipsoid or cylinder model nuclei. For comparison, a chromosome X-specific alphoid DNA probe was used to investigate the 2D distribution of chromosome X centric heterochromatin in the same cell types. Two dimensional Xc-Xc and Xc-CNI distances fit a random distribution in diploid normal and Bloom's syndrome nuclei, as well as in nuclei with trisomy X. The different distributions of 18c and Xc targets were confirmed by the simultaneous staining of these targets in different colors within individual nuclei using a double in situ hybridization approach
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