103 research outputs found
ФОРМЫ ИНТЕРАКТИВНЫХ МЕТОДОВ ОБУЧЕНИЯ МАТЕМАТИЧЕСКИМ ДИСЦИПЛИНАМ
To the article the types of interactive employments that areused at educating of students of faculty of computer and fundamental sciences (FCFS) Pacific state university (PNU, Khabarovsk) are driven. Ananalysis over of results of educating of students is brought on such employments.В статье приведены виды интерактивных заданий, которые применяются при обучении студентов факультета компьютерных и фундаментальных наук (ФКФН) Тихоокеанский государственный университет (ТОГУ, г. Хабаровск). Приведен анализ результатов обучения студентов на таких занятиях
Поддержка эволюции визуальных языков в платформе QReal
Like other software artefacts, DSMLs evolve in time. When a DSML changes, instance models might no longer conform to the new DSML metamodel and hence cannot be manipulated with a modelling tool. Therefore, a need for models migration to a new version of metamodel arises. Today, various approaches to this problem exist - from entirely manual to mostly automated. This paper describes a hybrid approach to model migration implemented in DSM platform QReal, which is being developed by the research group of Software Engineering Chair of St. Petersburg State University. That DSM platform implies some specific requirements, such as the support of metamodel interpretation and metamodeling “on the fly” modes. The presented approach realizes model migration when using one of those specific features. Как и другие программные продукты, языки моделирования развиваются со временем. В результате изменений в языке, модели на данном языке могут перестать соответствовать новой метамодели языка, что ведет к невозможности работы с ними с помощью инструментов моделирования. Таким образом, возникает проблема переноса моделей на новую версию языка. В настоящее время существуют различные подходы к решению данной проблемы – от полностью ручных до практически полностью автоматизированных. Данная статья описывает гибридный подход к миграции моделей, реализованный в DSM- платформе QReal, разрабатываемой на кафедре системного программирования Санкт-Петербургского государственного университета. Рассматриваемая система накладывает некоторые специфические требования, такие как под- держка режимов интерпретации метамодели и метамоделирования “на лету”. Представленный в статье подход реализует миграцию моделей при использовании данных возможностей
Bioinformatic and statistical analysis of the optic nerve head in a primate model of ocular hypertension
<p>Abstract</p> <p>Background</p> <p>The nonhuman primate model of glaucomatous optic neuropathy most faithfully reproduces the human disease. We used high-density oligonucleotide arrays to investigate whole genome transcriptional changes occurring at the optic nerve head during primate experimental glaucoma.</p> <p>Results</p> <p>Laser scarification of the trabecular meshwork of cynomolgus macaques produced elevated intraocular pressure that was monitored over time and led to varying degrees of damage in different samples. The macaques were examined clinically before enucleation and the myelinated optic nerves were processed post-mortem to determine the degree of neuronal loss. Global gene expression was examined in dissected optic nerve heads with Affymetrix GeneChip microarrays. We validated a subset of differentially expressed genes using qRT-PCR, immunohistochemistry, and immuno-enriched astrocytes from healthy and glaucomatous human donors. These genes have previously defined roles in axonal outgrowth, immune response, cell motility, neuroprotection, and extracellular matrix remodeling.</p> <p>Conclusion</p> <p>Our findings show that glaucoma is associated with increased expression of genes that mediate axonal outgrowth, immune response, cell motility, neuroprotection, and ECM remodeling. These studies also reveal that, as glaucoma progresses, retinal ganglion cell axons may make a regenerative attempt to restore lost nerve cell contact.</p
Gene Expression and Functional Studies of the Optic Nerve Head Astrocyte Transcriptome from Normal African Americans and Caucasian Americans Donors
To determine whether optic nerve head (ONH) astrocytes, a key cellular component of glaucomatous neuropathy, exhibit differential gene expression in primary cultures of astrocytes from normal African American (AA) donors compared to astrocytes from normal Caucasian American (CA) donors.We used oligonucleotide Affymetrix microarray (HG U133A & HG U133A 2.0 chips) to compare gene expression levels in cultured ONH astrocytes from twelve CA and twelve AA normal age matched donor eyes. Chips were normalized with Robust Microarray Analysis (RMA) in R using Bioconductor. Significant differential gene expression levels were detected using mixed effects modeling and Statistical Analysis of Microarray (SAM). Functional analysis and Gene Ontology were used to classify differentially expressed genes. Differential gene expression was validated by quantitative real time RT-PCR. Protein levels were detected by Western blots and ELISA. Cell adhesion and migration assays tested physiological responses. Glutathione (GSH) assay detected levels of intracellular GSH.Multiple analyses selected 87 genes differentially expressed between normal AA and CA (P<0.01). The most relevant genes expressed in AA were categorized by function, including: signal transduction, response to stress, ECM genes, migration and cell adhesion.These data show that normal astrocytes from AA and CA normal donors display distinct expression profiles that impact astrocyte functions in the ONH. Our data suggests that differences in gene expression in ONH astrocytes may be specific to the development and/or progression of glaucoma in AA
Network analysis of human glaucomatous optic nerve head astrocytes
<p>Abstract</p> <p>Background</p> <p>Astrocyte activation is a characteristic response to injury in the central nervous system, and can be either neurotoxic or neuroprotective, while the regulation of both roles remains elusive.</p> <p>Methods</p> <p>To decipher the regulatory elements controlling astrocyte-mediated neurotoxicity in glaucoma, we conducted a systems-level functional analysis of gene expression, proteomic and genetic data associated with reactive optic nerve head astrocytes (ONHAs).</p> <p>Results</p> <p>Our reconstruction of the molecular interactions affected by glaucoma revealed multi-domain biological networks controlling activation of ONHAs at the level of intercellular stimuli, intracellular signaling and core effectors. The analysis revealed that synergistic action of the transcription factors AP-1, vitamin D receptor and Nuclear Factor-kappaB in cross-activation of multiple pathways, including inflammatory cytokines, complement, clusterin, ephrins, and multiple metabolic pathways. We found that the products of over two thirds of genes linked to glaucoma by genetic analysis can be functionally interconnected into one epistatic network via experimentally-validated interactions. Finally, we built and analyzed an integrative disease pathology network from a combined set of genes revealed in genetic studies, genes differentially expressed in glaucoma and closely connected genes/proteins in the interactome.</p> <p>Conclusion</p> <p>Our results suggest several key biological network modules that are involved in regulating neurotoxicity of reactive astrocytes in glaucoma, and comprise potential targets for cell-based therapy.</p
Opposing Roles for Membrane Bound and Soluble Fas Ligand in Glaucoma-Associated Retinal Ganglion Cell Death
Glaucoma, the most frequent optic neuropathy, is a leading cause of blindness worldwide. Death of retinal ganglion cells (RGCs) occurs in all forms of glaucoma and accounts for the loss of vision, however the molecular mechanisms that cause RGC loss remain unclear. The pro-apoptotic molecule, Fas ligand, is a transmembrane protein that can be cleaved from the cell surface by metalloproteinases to release a soluble protein with antagonistic activity. Previous studies documented that constitutive ocular expression of FasL maintained immune privilege and prevented neoangeogenesis. We now show that FasL also plays a major role in retinal neurotoxicity. Importantly, in both TNFα triggered RGC death and a spontaneous model of glaucoma, gene-targeted mice that express only full-length FasL exhibit accelerated RGC death. By contrast, FasL-deficiency, or administration of soluble FasL, protected RGCs from cell death. These data identify membrane-bound FasL as a critical effector molecule and potential therapeutic target in glaucoma
Do Neutrophils Play a Role in Establishing Liver Abscesses and Distant Metastases Caused by Klebsiella pneumoniae?
Serotype K1 Klebsiella pneumoniae is a major cause of liver abscesses and endophthalmitis. This study was designed to identify the role of neutrophils in the development of distant metastatic complications that were caused by serotype K1 K. pneumoniae. An in vitro cellular model was used to assess serum resistance and neutrophil-mediated killing. BALB/c mice were injected with neutrophils containing phagocytosed K. pneumoniae. Serotype K1 K. pneumoniae was significantly more resistant to serum killing, neutrophil-mediated phagocytosis and intra-cellular killing than non-K1 isolates (p<0.01). Electron microscopic examination had similar findings as in the bioassay findings. Intraperitoneal injection of neutrophils containing phagocytosed serotype K1 K. pneumoniae led to abscess formation in multiple sites including the subcutaneous tissue, lung, and liver, whereas no abscess formation was observed in mice injected with non-K1 isolates. The resistance of serotype K1 K. pneumoniae to complement- and neutrophil-mediated intracellular killing results in the dissemination of K. pneumoniae via the bloodstream. Escape from neutrophil intracellular killing may contribute to the dissemination and establishment of distant metastases. Thus, neutrophils play a role as a vehicle for helping K. pneumoniae and contributing to the establishment of liver abscess and distant metastatic complications
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