43 research outputs found

    The Possibility of Noticing the Cyclists Based on Reflective Effect of the Elements on the Bicycle Pedals

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    The article presents the results of the research describing the changes of bicycle pedal angle relative to the ground, depending on the bicycle crank setting, and the impact of these parameters on detecting the reflective effect emitted by the reflective elements mounted on the bicycle pedals. The results of the road tests determining the cyclist detecting by a car driver, when bicycle is equipped only with bicycle pedals, reflective lights, illuminated with car′s passing lights are also presented. The research described in this article has been carried out for the purpose of reviewing the causes of traffic accidents, occurring at night, in the areas not illuminated by the street lights, in which the cyclists using defective bicycles (according to the regulations) took part

    The Framework Catalogue of Digital Competences

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    The Framework Catalogue of Digital Competences Justyna Jasiewicz, Mirosław Filiciak, Anna Mierzecka, Kamil Śliwowski, Andrzej Klimczuk, Małgorzata Kisilowska, Alek Tarkowski & Jacek Zadrożny Centrum Cyfrowe Projekt: Polska (2015

    Cytostatic factor inactivation is induced by a calcium-dependent mechanism present until the second cell cycle in fertilized but not in parthenogenetically activated mouse eggs

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    Cytostatic factor (CSF) is an activity responsible for the metaphase II arrest in vertebrate oocytes. This activity maintains a high level of maturation promoting factor (MPF) in the oocyte and both activities are destroyed after fertilization or parthenogenetic activation. To study some of the characteristics of the mechanism involved in MPF and CSF destruction, we constructed hybrid cells between metaphase II arrested oocytes and early embryos obtained after fertilization or artificial activation. We found that the behavior of hybrid cells differed depending upon the type of oocyte activation. Initially, the reaction of both types of hybrid cells was similar, the nuclear envelope broke down and chromatin condensation was induced. However, while metaphase II oocytes fused with parthenogenetic eggs remained arrested in M-phase, the oocytes fused with fertilized eggs underwent activation and passed into interphase. This ability of fertilized eggs to induce oocyte activation was still present at the beginning, but not at the end of the second embryonic cell cycle. Oocyte activation induced by fusion with a fertilized egg could be prevented when calcium was chelated by BAPTA. Thus, element(s) of the mechanism involved in calcium release triggered by a sperm component at fertilization remain(s) active until the second cell cycle and is (are) inactivated before the end of the 2-cell stage

    Ramowy Katalog Kompetencji Cyfrowych

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    Ramowy Katalog Kompetencji Cyfrowych Justyna Jasiewicz, Mirosław Filiciak, Anna Mierzecka, Kamil Śliwowski, Andrzej Klimczuk, Małgorzata Kisilowska, Alek Tarkowski & Jacek Zadrożny Centrum Cyfrowe Projekt: Polska (2015

    Cytostatic factor inactivation is induced by a calcium-dependent mechanism present until the second cell cycle in fertilized but not in parthenogenetically activated mouse eggs

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    Cytostatic factor (CSF) is an activity responsible for the metaphase II arrest in vertebrate oocytes. This activity maintains a high level of maturation promoting factor (MPF) in the oocyte and both activities are destroyed after fertilization or parthenogenetic activation. To study some of the characteristics of the mechanism involved in MPF and CSF destruction, we constructed hybrid cells between metaphase II arrested oocytes and early embryos obtained after fertilization or artificial activation. We found that the behavior of hybrid cells differed depending upon the type of oocyte activation. Initially, the reaction of both types of hybrid cells was similar, the nuclear envelope broke down and chromatin condensation was induced. However, while metaphase II oocytes fused with parthenogenetic eggs remained arrested in M-phase, the oocytes fused with fertilized eggs underwent activation and passed into interphase. This ability of fertilized eggs to induce oocyte activation was still present at the beginning, but not at the end of the second embryonic cell cycle. Oocyte activation induced by fusion with a fertilized egg could be prevented when calcium was chelated by BAPTA. Thus, element(s) of the mechanism involved in calcium release triggered by a sperm component at fertilization remain(s) active until the second cell cycle and is (are) inactivated before the end of the 2-cell stage

    Beta-Amyloid Peptides Enhance the Proliferative Response of Activated CD4+CD28+ Lymphocytes from Alzheimer Disease Patients and from Healthy Elderly

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    Alzheimer's disease (AD) is the most frequent form of dementia among elderly. Despite the vast amount of literature on non-specific immune mechanisms in AD there is still little information about the potential antigen-specific immune response in this pathology. It is known that early stages of AD include β-amyloid (Aβ)- reactive antibodies production and inflammatory response. Despite some evidence gathered proving cellular immune response background in AD pathology, the specific reactions of CD4+ and CD8+ cells remain unknown as the previous investigations yielded conflicting results. Here we investigated the CD4+CD28+ population of human peripheral blood T cells and showed that soluble β-amyloids alone were unable to stimulate these cells to proliferate significantly, resulting only in minor, probably antigen-specific, proliferative response. On the other hand, the exposure of in vitro pre-stimulated lymphocytes to soluble Aβ peptides significantly enhanced the proliferative response of these cells which had also lead to increased levels of TNF, IL-10 and IL-6. We also proved that Aβ peptide-enhanced proliferative response of CD4+CD28+ cells is autonomous and independent from disease status while being associated with the initial, ex vivo activation status of the CD4+ cells. In conclusion, we suggest that the effect of Aβ peptides on the immune system of AD patients does not depend on the specific reactivity to Aβ epitope(s), but is rather a consequence of an unspecific modulation of the cell cycle dynamics and cytokine production by T cells, occurring simultaneously in a huge proportion of Aβ peptide-exposed T lymphocytes and affecting the immune system performance

    Embryonic Diapause Is Conserved across Mammals

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    Embryonic diapause (ED) is a temporary arrest of embryo development and is characterized by delayed implantation in the uterus. ED occurs in blastocysts of less than 2% of mammalian species, including the mouse (Mus musculus). If ED were an evolutionarily conserved phenomenon, then it should be inducible in blastocysts of normally non-diapausing mammals, such as domestic species. To prove this hypothesis, we examined whether blastocysts from domestic sheep (Ovis aries) could enter into diapause following their transfer into mouse uteri in which diapause conditions were induced. Sheep blastocysts entered into diapause, as demonstrated by growth arrest, viability maintenance and their ED-specific pattern of gene expression. Seven days after transfer, diapausing ovine blastocysts were able to resume growth in vitro and, after transfer to surrogate ewe recipients, to develop into normal lambs. The finding that non-diapausing ovine embryos can enter into diapause implies that this phenomenon is phylogenetically conserved and not secondarily acquired by embryos of diapausing species. Our study questions the current model of independent evolution of ED in different mammalian orders

    The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

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    The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan

    W\u142adza i spo\u142ecze\u144stwo w systemie autorytarnym / Socjologia \u15bwiata polityki, t. 1

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    S\u142owa kluczowe: socjologia w\u142adzy komunistycznej; legitymizacja w\u142adzy lokalnej; przyczyny pos\u142usze\u144stwa wobec w\u142adzy; nieformalne mechanizmy i struktury \u17cycia politycznego; klientelizm i patrona\u17c w systemie scentralizowanym i w okresie transformacj

    Patroni i klienci / Socjologia \u15bwiata polityki, t. 2

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    S\u142owa kluczowe: klientelizm i patrona\u17c w systemie scentralizowanym i w okresie transformacji; w\u142adza i polityka lokalna w Polsce; nieformalne mechanizmy i struktury \u17cycia politycznego; rozw\uf3j antropologii spo\u142ecze\u144stw z\u142o\u17conych; korupcja \u17cycia polityczneg
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