228 research outputs found

    Формирование изображения нарушителя в радиолучевых системах охраны

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    В статье рассмотрены вопросы улучшения информационных характеристик двухпозиционных радио- лучевых технических систем охраны. В качестве первого приближения сигналообразования использована лучевая модель формирования интерференционной картины ЭМ-волны. Разработан метод формирования двумерного изображения нарушителя в виде теневого силуэта. Получено обратное преобразование Кирхгофа, связывающее функцию пропускания объекта с распределением комплексной амплитуды ЭМ-волны в плоскости приема.У статті розглянуті питання поліпшення інформаційних характеристик двопозиційних радіопроменевих технічних систем охорони. Як перше наближення сигналостворення використана променева модель формування інтерференційної картини ЕМ-хвилі. Розроблено метод формування двовимірного зображення порушника у вигляді тіньового силуету. Отримано зворотне перетворення Кірхгофа, що зв’язує функцію пропускання об’єкта з розподілом комплексної амплітуди ЕМ-хвилі в площині прийому.The article deals with the issues of improving information characteristics of two-position radio-beam technical protection systems. The beam model of forming EM wav interference pattern is used as the first approximation of signal forming. The method of forming the intruder’s two-dimensional image as a shadow silhouette has been developed. The author has drawn the Kirchhoff inversion connecting the object’s transmission function with the distribution of the EM wave complex amplitude in the reception plane

    Long non-coding RNAs in motor neuron development and disease

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    Long non-coding RNAs (lncRNAs) are RNAs that exceed 200 nucleotides in length and that are not translated into proteins. Thousands of lncRNAs have been identified with functions in processes such as transcription and translation regulation, RNA processing, and RNA and protein sponging. LncRNAs show prominent expression in the nervous system and have been implicated in neural development, function and disease. Recent work has begun to report on the expression and roles of lncRNAs in motor neurons (MNs). The cell bodies of MNs are located in cortex, brainstem or spinal cord and their axons project into the brainstem, spinal cord or towards peripheral muscles, thereby controlling important functions such as movement, breathing and swallowing. Degeneration of MNs is a pathological hallmark of diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. LncRNAs influence several aspects of MN development and disruptions in these lncRNA-mediated effects are proposed to contribute to the pathogenic mechanisms underlying MN diseases (MNDs). Accumulating evidence suggests that lncRNAs may comprise valuable therapeutic targets for different MNDs. In this review, we discuss the role of lncRNAs (including circular RNAs [circRNAs]) in the development of MNs, discuss how lncRNAs may contribute to MNDs and provide directions for future research

    Genetics of Amyotrophic Lateral Sclerosis

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    La sclérose latérale amyotrophique (SLA) est la maladie des neurones moteurs la plus fréquente, affectant 4-6 individus par 100,000 habitants à l’échelle mondiale. La maladie se caractérise par une faiblesse et une atrophie musculaire suite à la dégénérescence des neurones du cortex moteur, tronc cérébral et moelle épinière. Les personnes atteintes développent les premiers symptômes à l’âge adulte et la maladie progresse sur une période de trois à cinq ans. Il a été répertorié qu’environ 10% des patients ont une histoire familiale de SLA; 90% des gens affectés le sont donc de façon sporadique. La découverte il y a 19 ans de mutations dans le gène zinc/copper superoxide dismutase (SOD1), présentes dans 15-20% des cas familiaux de SLA et environ 2% du total des individus affectés, a été l’événement déclencheur pour la découverte de variations génétiques responsables de la maladie. La recherche sur la génétique de la SLA a connu une progression rapide ces quatre dernières années avec l’identification de mutations dans de nouveaux gènes. Toutefois, même si certains de ces gènes ont été démontrés comme réellement liés à la maladie, la contribution d’autres gènes demeure incertaine puisque les résultats publiés de ceux-ci n’ont pas, à ce jour, été répliqués. Une portion substantielle de cas reste cependant à être génétiquement expliquée, et aucun traitement à ce jour n’a été démontré comme étant efficace pour remédier, atténuer ou prévenir la maladie. Le but du projet de recherche de doctorat était d’identifier de nouveaux gènes mutés dans la SLA, tout en évaluant la contribution de gènes nouvellement identifiés chez une importante cohorte multiethnique de cas familiaux et sporadiques. Les résultats présentés sont organisés en trois sections différentes. Dans un premier temps, la contribution de mutations présentes dans le gène FUS est évaluée chez les patients familiaux, sporadiques et juvéniles de SLA. Précisément, de nouvelles mutations sont rapportées et la proportion de mutations retrouvées chez les cas familiaux et sporadiques de SLA est évaluée. De plus, une nouvelle mutation est rapportée dans un cas juvénile de SLA; cette étude de cas est discutée. Dans un deuxième temps, de nouvelles avenues génétiques sont explorées concernant le gène SOD1. En effet, une nouvelle mutation complexe est rapportée chez une famille française de SLA. De plus, la possibilité qu’une mutation présente dans un autre gène impliqué dans la SLA ait un impact sur l’épissage du gène SOD1 est évaluée. Finalement, la dernière section explique la contribution de nouveaux gènes candidats chez les patients atteints de SLA. Spécifiquement, le rôle des gènes OPTN, SIGMAR1 et SORT1 dans le phénotype de SLA est évalué. Il est souhaité que nos résultats combinés avec les récents développements en génétique et biologie moléculaire permettent une meilleure compréhension du mécanisme pathologique responsable de cette terrible maladie tout en guidant le déploiement de thérapies suite à l’identification des cibles appropriées.Amyotrophic lateral sclerosis (ALS) is the most common of motor neuron diseases, affecting 4-6 individuals per 100,000 individuals worldwide. ALS is characterized by muscle weakness and atrophy caused by the degeneration of neurons located in the motor cortex, brain stem and spinal cord. This fatal disease generally has an adult onset and progresses over a three to five year period. While 10% of patients affected have a family history of the disease, 90% of cases do not and are considered sporadic. The finding of mutations in the zinc/copper superoxide dismutase gene (SOD1) gene 19 years ago in about 15-20% of familial ALS (FALS) patients and approximately 2% of overall cases developed the interest of identifying rare genetics variants causing the disease. The ALS research field experienced a rapid progression during the last four years as mutations in new genes have been identified. While mutations in some of those new genes have been clearly linked to ALS, the role of others is still questionable and so far has not been positively replicated in other populations. Importantly, a significant portion of cases still need to be genetically explained and, unfortunately, there is still no effective treatment to cure, attenuate or prevent the disease. The aim of this Ph.D research project was to identify new ALS mutated genes while analysing the causative role of other newly identified genes in a large familial and sporadic ALS cohort of different origins. The results presented here are categorized into three different sections. First, the contribution of FUS mutations to familial, sporadic and juvenile ALS is analysed. Specifically, new FUS mutations are reported in ALS cases and the proportions of variants present in the tested familial and sporadic ALS cohorts are assessed. In addition, a new mutation is reported in a juvenile ALS patient, and this interesting case is discussed. Second, new genetic avenues are explored for the SOD1 gene. Precisely, a new and complex SOD1 mutation is reported in a French ALS family. Moreover, the possibility that other ALS mutated genes influence SOD1 splicing events is evaluated. Third, the contribution of new candidate genes is evaluated. Precisely, the contribution of OPTN, SIGMAR1 and SORT1 genes to the ALS phenotype is assessed. Hopefully, our different findings combined with recent developments in genetics and molecular biology will permit a better understanding of the pathological mechanisms involved in the disease and will lead to the identification of the right targets in order to develop appropriate therapeutics for ALS patients

    Protocol for tissue clearing and 3D analysis of dopamine neurons in the developing mouse midbrain

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    Advances in tissue clearing enable analysis of complex migratory patterns of developing neurons in whole intact tissue. Here, we implemented a modified version of 3DISCO to study migration of midbrain dopamine (DA) neurons. We provide a detailed protocol starting from whole-brain immunostaining, tissue clearing, and ultramicroscopic imaging to post-acquisition quantification and analysis. This protocol enables precise quantification of DA neuron migration but can also be applied more generally for analyzing neuron migration throughout the nervous system. For complete details on the use and execution of this protocol, please refer to Brignani et al. (2020)

    The mouse brain after foot shock in four dimensions:Temporal dynamics at a single-cell resolution

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    Acute stress leads to sequential activation of functional brain networks. A biologically relevant question is exactly which (single) cells belonging to brain networks are changed in activity over time after acute stress across the entire brain. We developed a preprocessing and analytical pipeline to chart whole-brain immediate early genes’ expression—as proxy for cellular activity—after a single stressful foot shock in four dimensions: that is, from functional networks up to three-dimensional (3D) single-cell resolution and over time. The pipeline is available as an R package. Most brain areas (96%) showed increased numbers of c-fos+ cells after foot shock, yet hypothalamic areas stood out as being most active and prompt in their activation, followed by amygdalar, prefrontal, hippocampal, and finally, thalamic areas. At the cellular level, c-fos+ density clearly shifted over time across subareas, as illustrated for the basolateral amygdala. Moreover, some brain areas showed increased numbers of c-fos+ cells, while others—like the dentate gyrus—dramatically increased c-fos intensity in just a subset of cells, reminiscent of engrams; importantly, this “strategy” changed after foot shock in half of the brain areas. One of the strengths of our approach is that single-cell data were simultaneously examined across all of the 90 brain areas and can be visualized in 3D in our interactive web portal

    Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways

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    Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins
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