440 research outputs found
Weighted partially orderd sets of finite type
We define representations of weighted posets and
construct for them reflection functors. Using this technique we
prove that a weighted poset is of finite representation type if and
only if its Tits form is weakly positive; then indecomposable representations are in one-to-one correspondence with the positive roots
of the Tits form
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The exon junction complex senses energetic stress and regulates contractility and cell architecture in cardiac myocytes
The exon junction complex (EJC) is the main mechanism by which cells select specific mRNAs
for translation into protein. We hypothesized that the EJC is involved in the regulation
of gene expression during the stress response in cardiac myocytes, with implications for
the failing heart. In cultured rat neonatal myocytes, we examined the cellular distribution
of two EJC components eukaryotic translation initiation factor 4A isoform 3 (eIF4A3) and
mago nashi homologue (Mago) in response to metabolic stress. There was significant relocalization
of eIF4A3 and Mago from the nucleus to cytoplasm following 18 h of hypoxia.
Treating myocytes with 50 mM NaN3 for 4 h to mimic the metabolic stress induced by hypoxia
also resulted in significant relocalization of eIF4A3 and Mago to the cytoplasm. To
examine whether the effects of metabolic stress on the EJC proteins were dependent on
the metabolic sensor AMP kinase (AMPK), we treated myocytes with 1 μM dorsomorphin
(DM) in combination with NaN3. DM augmented the translocation of Mago and eIF4A3 from
the nucleus to the cytoplasm. Knockdown of eIF4A3 resulted in cessation of cell contractility
96 h post-treatment and a significant reduction in the number of intact sarcomeres.
Cell area was significantly reduced by both hypoxia and eIF4A3 knockdown, whilst eIF4A3
knockdown also significantly reduced nuclear size. The reduction in nuclear size is unlikely
to be related to apoptosis as it was reversed in combination with hypoxia. These data suggest
for the first time that eIF4A3 and potentially other EJC members play an important role
in the myocyte stress response, cell contractility and morphology
Experimental study of evaluation of mechanical parameters of heterogeneous porous structure
© Published under licence by IOP Publishing Ltd. The paper deals with the problem of determining the mechanical macroparameters of the porous material in case of knowing the information about it's structure. Fabric tensor and porosity was used to describe structure of the material. Experimental study presented. In research two-component liquid polyurethane plastics of cold curing Lasilcast (Lc-12) was used. Then samples was scanned on computer tomography. Resulting data was analyzed. Regular subvolume was cut out after analyses. Then mechanical tests was performed. As a result we get information about fabric tensor, porosity, Young's modulus and Poisson ratio of the sample. In the abstract presented results for some samples. Taking into account the law of porosity variation, we considered the problem of evaluating the mechanical macro parameters depending on the nature of the porous structure. To evaluate the macroparameters, we built the dependence of the Young's modules and Poisson ratio of the material on the rotation angle α and the pore ellipticity parameter λ. The sensitivity of the deformations to the elastic constants was also estimated
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Mass spectrometry imaging of glucosinolates in arabidopsis flowers and siliques
Glucosinolates are multi-functional plant secondary metabolites which play a vital role in plant defence and are, as dietary compounds, important to human health and livestock well-being. Knowledge of the tissue-specific regulation of their biosynthesis and accumulation is essential for plant breeding programs. Here, we report that in Arabidopsis thaliana, glucosinolates are accumulated differentially in specific cells of reproductive organs. Using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI), distribution patterns of three selected compounds, 4-methylsulfinylbutyl
(glucoraphanin), indol-3-ylmethyl (glucobrassicin), and 4-benzoyloxybutyl glucosinolates, were mapped in the tissues of whole flower buds, sepals and siliques. The results show that tissue localization patterns of aliphatic glucosinolate glucoraphanin and 4-benzoyloxybutyl glucosinolate were similar, but indole glucosinolate glucobrassicin had different localisation, indicating a possible difference in function. The high resolution images obtained by a complementary approach, cryo-SEM Energy Dispersive X-ray analysis (cryo-SEM-EDX), confirmed increased concentration of sulphur in areas with elevated amounts of glucosinolates, and allowed identifying the cell types implicated in accumulation of glucosinolates. High concentration of sulphur was found in S-cells adjacent to the phloem in pedicels and siliques, indicating the presence of glucosinolates. Moreover, both MALDI MSI and cryo-SEM-EDX analyses indicated accumulation of glucosinolates in cells on the outer surface of the sepals, suggesting that a layer of glucosinolate-accumulating epidermal cells protects the whole of the developing flower, in addition to the S-cells, which protect the phloem. This research demonstrates the high potential of MALDI MSI for understanding the cell-specific compartmentation of plant metabolites and its regulation
Optimal placement of issues supply the diffusers and exhaust air ducts general ventilation
At an article consider issues of improving industrial ventilation by optimal location of supply and exhaust devices General systems. Article include scheme of air movement by using different diffusers and exhaust devices and formulas to determine their optimal placement
Innovative Educational Resources as Effective Means of Overcoming Difficulties in Foreign Speaking Students of Non-Language Specialties
В статье актуализируется проблематика преодоления затруднений в иноязычном говорении студентов, обучающихся по направлениям технических специальностей. Автор подходит к решению данной проблемы путем разработки и реализации инновационных образовательных ресурсов. Цель статьи - разработать и определить эффективность инновационных образовательных ресурсов в процессе преодоления затруднений в иноязычном говорении студентами неязыковых вузов.The article actualizes the problem of overcoming difficulties in foreign language speaking of students studying in the areas of technical specialties. The author approaches this problem by developing and implementing innovative educational resources. The purpose of the article is to develop and determine the effectiveness of innovative educational resources in the process of overcoming difficulties in foreign language speaking by students of non-linguistic universities
The infrastructure of public catering in the context of tourist city space development
To assess the impact of environmental factors on the activities of catering enterprises of the Belgorod region and the quality of customer service, the authors proposed a method using STEP-analysis and SWOT-analysis. The analysis of environmental factors was carried out on the basis of the expert evaluation results conducted in two stage
Transformation of museum product
Today, each museum needs to develop an active strategy of market development, which is preceded by a comprehensive analysis of potential consumers of the museum product, on the basis of which the directions of development will be proposed. The conducted research allowed us to reveal a number of problems which are connected with necessity of transformation of the museum product providing satisfaction of visitor’s requirements and, at the same time, increase in the income of the museu
Fast electrochemical membrane actuator:Design, fabrication and preliminary testing
An actuator based on water electrolysis with a fast change of voltage polarity is presented. It demonstrates a new actuation principle allowing significant increase the operation frequency of the device due to fast termination of the produced gas. The actuator consists of a working chamber with metallic electrodes and supplying channels filled with an electrolyte. The chamber is formed in a layer of SU-8 and covered by a flexible polydimethylsiloxane membrane, which deforms as the pressure in the chamber increases. Design, fabrication procedure, and first tests of the actuator are described
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