: Familias populares e institução escolar : entre autonomia e heteronomia

Version française de "Familias populares e institução escolar : entre autonomia e heteronomia", Educação e Pesquisa, 2010, vol. 36, n°espcial, p. 65-76International audienceL'article se propose d'analyser quelques problèmes théoriques dans l'étude des relations entre familles populaires et école, problèmes qui sont ceux que rencontre la sociologie dans l'étude des classes populaires et de leurs relations avec le monde dominant et les institutions. Il explore la possibilité de dépasser l'alternative entre une perspective strictement légitimiste qui tend à réduire les classes populaires et leurs pratiques au rapport de domination qui les aliène (hétéronomie) et la perspective relativiste qui les envisage dans une altérité radicale (autonomie) en occultant les rapports sociaux de domination. Il insiste sur l'ambivalence des logiques et des pratiques des familles populaire

Ценообразование в сфере автомобильных грузовых перевозок

Creation of price in road freight transport in Central Europe has undergone significant changes in the last 30 years. Transporters in regulated economy used mandatory tariffs, after the liberalisation of the market they were subsequently not prepared for their own price creation. Price calculation has gone through several stages of development. At present, there are existing cost calculations that are based on the division of costs into variable and fixed ones. After the accession of Central European countries to the European Union, competition in this sector has increased significantly. When calculating the price for transport, transporters use a coefficient of exploitation of journeys, which adjust the costs associated with the transport so that the costs also take into account the journey with the vehicle, which the transporter must carry out without the shipment.The aim of this paper is to prove that from the point of view of the competitiveness of price creation it is not economically correct to use the coefficient of exploitation of journeys as a constant coefficient. The authors prove in the article that the value of the coefficient depends not only on the route of consignment transport but also on the time of transport realisation.Формирование цен на автомобильные грузовые перевозки в Центральной Европе за последние 30 лет претерпело значительные изменения. В регулируемой экономике перевозчики применяли обязательные тарифы, вследствие чего после либерализации рынка они оказались не готовы к самостоятельному ценообразованию. Расчёты цен прошли несколько этапов развития. В настоящее время сложились системы расчёта затрат, основанные на разделении затрат на переменные и постоянные. После присоединения стран Центральной Европы к Европейскому союзу конкуренция в этом секторе значительно возросла. При расчёте цены на транспортировку перевозчики используют коэффициент использования поездок (рейсов), который корректирует расходы, связанные с перевозкой, с учётом порожнего перемещения транспортного средства, которое должен осуществить перевозчик.Цель данной статьи – доказать, что с точки зрения конкурентоспособности ценообразования применение коэффициента использования поездок в качестве постоянного коэффициента экономически необоснованно. В статье авторы доказывают, что значение коэффициента зависит не только от маршрута грузоперевозки, но и от времени, затрачиваемого на осуществление перевозки

Clustering of neuronal potassium channels is independent of their interaction with PSD-95

Voltage-dependent potassium channels regulate membrane excitability and cell–cell communication in the mammalian nervous system, and are found highly localized at distinct neuronal subcellular sites. Kv1 (mammalian Shaker family) potassium channels and the neurexin Caspr2, both of which contain COOH-terminal PDZ domain binding peptide motifs, are found colocalized at high density at juxtaparanodes flanking nodes of Ranvier of myelinated axons. The PDZ domain–containing protein PSD-95, which clusters Kv1 potassium channels in heterologous cells, has been proposed to play a major role in potassium channel clustering in mammalian neurons. Here, we show that PSD-95 colocalizes precisely with Kv1 potassium channels and Caspr2 at juxtaparanodes, and that a macromolecular complex of Kv1 channels and PSD-95 can be immunopurified from mammalian brain and spinal cord. Surprisingly, we find that the high density clustering of Kv1 channels and Caspr2 at juxtaparanodes is normal in a mutant mouse lacking juxtaparanodal PSD-95, and that the indirect interaction between Kv1 channels and Caspr2 is maintained in these mutant mice. These data suggest that the primary function of PSD-95 at juxtaparanodes lies outside of its accepted role in mediating the high density clustering of Kv1 potassium channels at these sites

New functional appearances of stable expressions in the media texts of the russian-ukrainian war period

У науковій розвідці проаналізовано усталені вислови, засвідчені в текстах сучасних українських ЗМІ в період російсько-української війни (2022-2024 рр.). Корпус зібраного матеріалу вважаємо інноваційним, оскільки джерельна база охоплює сучасні інформаційні платформи різних типів і форм власності. Відповідно до сформульованої мети у статті досліджено функціональні особливості та виявлено параметричні характеристики сет-висловлень у мові сучасних мас-медіа, з'ясовано їхній трансформаційний потенціал і стилістичну роль. Досягнення поставленої мети стало можливим завдяки розв'язанню таких завдань 1) схарактеризувати сталі вирази в контексті сучасної лінгвістичної парадигми; 2) окреслити актуальні позамовні чинники, що впливають на творення трансформованих сполук; 3) виокремити тематику публікацій, у яких використано різні за формою та значенням сталі вирази; 4) проаналізувати негативно-оцінні та експресивні мовні одиниці, засвідчені в мові українських ЗМІ у 2022-2024 роках. Виявлено, що в текстах сучасних ЗМІ функціонують прислів'я, приказки, фразеологізми, крилаті вислови тощо. Найбільш стійкі вирази представлені в текстах про російсько-українську війну, лідерів Росії та Білорусі. Виявлено, що усталені словосполучення активно використовуються в публікаціях про міжнародні відносини, різні проблемні та конфліктні ситуації, економічні, управлінські та ділові справи, менше проаналізованих мовних одиниць зафіксовано в тематиці спорту та відпочинку, мистецтва та науки, а також у світських новинах. Домінанту формують усталені вирази, представлені в академічних та онлайн-словниках, їм кількісно поступаються новоутворення та трансформовані відомі вирази. Здебільшого усталені сполуки позначають негативні процеси та дії, часто негативно характеризують відомих осіб. Експресивність текстів українських мас-медіа належить до низки функціональних особливостей аналізованих мовних одиниць.In the scientific research, set expressions attested in the texts of modern Ukrainian mass media during the period of the Russian-Ukrainian war (2022-2024) were analyzed. We consider the corpus of collected material to be innovative, as the source base covers modern information platforms of various types and forms of ownership. In accordance with the formulated goal, the article investigates the functional features and reveals the parametric characteristics of set expressions in the language of modern mass media, and their transformational potential and stylistic role are clarified. Achieving the set goal appeared possible due to solution of the following tasks: 1) to characterize set expressions in the context of the modern linguistic paradigm; 2) to outline actual non-speech factors affecting the creation of transformed compounds; 3) to highlight the topics of publications that use stable expressions of different form and meaning; 4) to analyze negative-evaluative and expressive language units, attested in the language of the Ukrainian mass media in 2022–2024,. It was found that proverbs, sayings, phraseological units, catchphrases, etc. function in the texts of modern mass media. The most stable expressions are presented in texts about the Russian-Ukrainian war, the leaders of Russia and Belarus. It was found that established phrases are actively used in publications about international relations, various problematic and conflict situations, economic, managerial and business affairs, less analyzed language units are recorded in the topics of sports and recreation, art and science, and in lay news. The dominant is formed by set expressions presented in academic and online dictionaries; new formations and transformed known expressions are quantitatively inferior to them. For the most part, established compounds indicate negative processes and actions, often negatively characterize famous persons. Expressiveness of Ukrainian mass media texts belongs to a number of functional features of the analyzed language unit

Protein 4.1B Contributes to the Organization of Peripheral Myelinated Axons

Neurons are characterized by extremely long axons. This exceptional cell shape is likely to depend on multiple factors including interactions between the cytoskeleton and membrane proteins. In many cell types, members of the protein 4.1 family play an important role in tethering the cortical actin-spectrin cytoskeleton to the plasma membrane. Protein 4.1B is localized in myelinated axons, enriched in paranodal and juxtaparanodal regions, and also all along the internodes, but not at nodes of Ranvier where are localized the voltage-dependent sodium channels responsible for action potential propagation. To shed light on the role of protein 4.1B in the general organization of myelinated peripheral axons, we studied 4.1B knockout mice. These mice displayed a mildly impaired gait and motility. Whereas nodes were unaffected, the distribution of Caspr/paranodin, which anchors 4.1B to the membrane, was disorganized in paranodal regions and its levels were decreased. In juxtaparanodes, the enrichment of Caspr2, which also interacts with 4.1B, and of the associated TAG-1 and Kv1.1, was absent in mutant mice, whereas their levels were unaltered. Ultrastructural abnormalities were observed both at paranodes and juxtaparanodes. Axon calibers were slightly diminished in phrenic nerves and preterminal motor axons were dysmorphic in skeletal muscle. βII spectrin enrichment was decreased along the axolemma. Electrophysiological recordings at 3 post-natal weeks showed the occurrence of spontaneous and evoked repetitive activity indicating neuronal hyperexcitability, without change in conduction velocity. Thus, our results show that in myelinated axons 4.1B contributes to the stabilization of membrane proteins at paranodes, to the clustering of juxtaparanodal proteins, and to the regulation of the internodal axon caliber

Substrate Micropatterning as a New in Vitro Cell Culture System to Study Myelination

Artículo de publicación ISIMyelination is a highly regulated developmental process whereby oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system ensheathe axons with a multilayered concentric membrane. Axonal myelination increases the velocity of nerve impulse propagation. In this work, we present a novel in vitro system for coculturing primary dorsal root ganglia neurons along with myelinating cells on a highly restrictive and micropatterned substrate. In this new coculture system, neurons survive for several weeks, extending long axons on defined Matrigel tracks. On these axons, myelinating cells can achieve robust myelination, as demonstrated by the distribution of compact myelin and nodal markers. Under these conditions, neurites and associated myelinating cells are easily accessible for studies on the mechanisms of myelin formation and on the effects of axonal damage on the myelin sheath.Regenerative Medicine and Nanomedicine Initiative of the Canadian Institutes of Health Research (CIHR) RMF-7028 FONDECYT 1080252 CIHR Ministry of Industry of Canada Rio Tinto Alcan Molson Foundatio

The Tumor Suppressor PRDM5 Regulates Wnt Signaling at Early Stages of Zebrafish Development

PRDM genes are a family of transcriptional regulators that modulate cellular processes such as differentiation, cell growth and apoptosis. Some family members are involved in tissue or organ maturation, and are differentially expressed in specific phases of embryonic development. PRDM5 is a recently identified family member that functions as a transcriptional repressor and behaves as a putative tumor suppressor in different types of cancer. Using gene expression profiling, we found that transcriptional targets of PRDM5 in human U2OS cells include critical genes involved in developmental processes, and specifically in regulating wnt signaling. We therefore assessed PRDM5 function in vivo by performing loss-of-function and gain-of-function experiments in zebrafish embryos. Depletion of prdm5 resulted in impairment of morphogenetic movements during gastrulation and increased the occurrence of the masterblind phenotype in axin+/− embryos, characterized by the loss of eyes and telencephalon. Overexpression of PRDM5 mRNA had opposite effects on the development of anterior neural structures, and resulted in embryos with a shorter body axis due to posterior truncation, a bigger head and abnormal somites. In situ hybridization experiments aimed at analyzing the integrity of wnt pathways during gastrulation at the level of the prechordal plate revealed inhibition of non canonical PCP wnt signaling in embryos overexpressing PRDM5, and over-activation of wnt/β-catenin signaling in embryos lacking Prdm5. Our data demonstrate that PRDM5 regulates the expression of components of both canonical and non canonical wnt pathways and negatively modulates wnt signaling in vivo

Verification of genes differentially expressed in neuroblastoma tumours: a study of potential tumour suppressor genes

<p>Abstract</p> <p>Background</p> <p>One of the most striking features of the childhood malignancy neuroblastoma (NB) is its clinical heterogeneity. Although there is a great need for better clinical and biological markers to distinguish between tumours with different severity and to improve treatment, no clear-cut prognostic factors have been found. Also, no major NB tumour suppressor genes have been identified.</p> <p>Methods</p> <p>In this study we performed expression analysis by quantitative real-time PCR (QPCR) on primary NB tumours divided into two groups, of favourable and unfavourable outcome respectively. Candidate genes were selected on basis of lower expression in unfavourable tumour types compared to favourables in our microarray expression analysis. Selected genes were studied in two steps: (1) using TaqMan Low Density Arrays (TLDA) targeting 89 genes on a set of 12 NB tumour samples, and (2) 12 genes were selected from the TLDA analysis for verification using individual TaqMan assays in a new set of 13 NB tumour samples.</p> <p>Results</p> <p>By TLDA analysis, 81 out of 87 genes were found to be significantly differentially expressed between groups, of which 14 have previously been reported as having an altered gene expression in NB. In the second verification round, seven out of 12 transcripts showed significantly lower expression in unfavourable NB tumours, <it>ATBF1</it>, <it>CACNA2D3</it>, <it>CNTNAP2</it>, <it>FUSIP1</it>, <it>GNB1</it>, <it>SLC35E2</it>, and <it>TFAP2B</it>. The gene that showed the highest fold change in the TLDA analysis, <it>POU4F2</it>, was investigated for epigenetic changes (CpG methylation) and mutations in order to explore the cause of the differential expression. Moreover, the fragile site gene <it>CNTNAP2 </it>that showed the largest fold change in verification group 2 was investigated for structural aberrations by copy number analysis. However, the analyses of <it>POU4F2 </it>and <it>CNTNAP2 </it>showed no genetic alterations that could explain a lower expression in unfavourable NB tumours.</p> <p>Conclusion</p> <p>Through two steps of verification, seven transcripts were found to significantly discriminate between favourable and unfavourable NB tumours. Four of the transcripts, <it>CACNA2D3</it>, <it>GNB1</it>, <it>SLC35E2</it>, and <it>TFAP2B</it>, have been observed in previous microarray studies, and are in this study independently verified. Our results suggest these transcripts to be markers of malignancy, which could have a potential usefulness in the clinic.</p

Genomic microsatellites identify shared Jewish ancestry intermediate between Middle Eastern and European populations

<p>Abstract</p> <p>Background</p> <p>Genetic studies have often produced conflicting results on the question of whether distant Jewish populations in different geographic locations share greater genetic similarity to each other or instead, to nearby non-Jewish populations. We perform a genome-wide population-genetic study of Jewish populations, analyzing 678 autosomal microsatellite loci in 78 individuals from four Jewish groups together with similar data on 321 individuals from 12 non-Jewish Middle Eastern and European populations.</p> <p>Results</p> <p>We find that the Jewish populations show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure. Further, Bayesian clustering, neighbor-joining trees, and multidimensional scaling place the Jewish populations as intermediate between the non-Jewish Middle Eastern and European populations.</p> <p>Conclusion</p> <p>These results support the view that the Jewish populations largely share a common Middle Eastern ancestry and that over their history they have undergone varying degrees of admixture with non-Jewish populations of European descent.</p

Human Neural Stem Cells Differentiate and Promote Locomotor Recovery in an Early Chronic Spinal coRd Injury NOD-scid Mouse Model

Traumatic spinal cord injury (SCI) results in partial or complete paralysis and is characterized by a loss of neurons and oligodendrocytes, axonal injury, and demyelination/dysmyelination of spared axons. Approximately 1,250,000 individuals have chronic SCI in the U.S.; therefore treatment in the chronic stages is highly clinically relevant. Human neural stem cells (hCNS-SCns) were prospectively isolated based on fluorescence-activated cell sorting for a CD133(+) and CD24(-/lo) population from fetal brain, grown as neurospheres, and lineage restricted to generate neurons, oligodendrocytes and astrocytes. hCNS-SCns have recently been transplanted sub-acutely following spinal cord injury and found to promote improved locomotor recovery. We tested the ability of hCNS-SCns transplanted 30 days post SCI to survive, differentiate, migrate, and promote improved locomotor recovery.hCNS-SCns were transplanted into immunodeficient NOD-scid mice 30 days post spinal cord contusion injury. hCNS-SCns transplanted mice demonstrated significantly improved locomotor recovery compared to vehicle controls using open field locomotor testing and CatWalk gait analysis. Transplanted hCNS-SCns exhibited long-term engraftment, migration, limited proliferation, and differentiation predominantly to oligodendrocytes and neurons. Astrocytic differentiation was rare and mice did not exhibit mechanical allodynia. Furthermore, differentiated hCNS-SCns integrated with the host as demonstrated by co-localization of human cytoplasm with discrete staining for the paranodal marker contactin-associated protein.The results suggest that hCNS-SCns are capable of surviving, differentiating, and promoting improved locomotor recovery when transplanted into an early chronic injury microenvironment. These data suggest that hCNS-SCns transplantation has efficacy in an early chronic SCI setting and thus expands the "window of opportunity" for intervention