104 research outputs found

    Realizacja praw podatników (przedsiębiorstw cyfrowych) w świetle umów o unikaniu podwójnego opodatkowania

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    The article discusses the implementation of the right of taxpayers-digital companies in the framework of the double tax avoidance agreements (hereinafter referred to as the DTAA) to exemption from taxation in the state-source of income. As a result of the analysis of the norms contained in international agreements on the avoidance of double taxation, ways to address the issue of taxation of digital companies in the framework of international tax legislation are proposed. The authors of the article proved the need to amend the provisions of the DTAA and, in particular, change the term ‘permanent establishment’ and proposed the introduction of the concept of a ‘digital’ permanent establishment for the purpose of establishing the tax presence of a company in the relevant jurisdictions, with reference to the location of users and customers of such companies.W artykule omówiono realizację prawa podatników – przedsiębiorstw cyfrowych – do zwolnienia z podatku w państwie źródle dochodu w kontekście umów o unikaniu podwójnego opodatkowania (zwanych dalej: UUPO). Na podstawie analizy norm zawartych w międzynarodowych umowach o unikaniu podwójnego opodatkowania zaproponowano sposoby rozwiązania problemu opodatkowania przedsiębiorstw cyfrowych w ramach umów o unikaniu podwójnego opodatkowania. Autorzy artykułu wskazują na potrzebę dokonania nowelizacji przepisów UUPO, a w szczególności modyfikacji terminu „zakład stały”, proponują także wprowadzenie pojęcia „cyfrowego” zakładu stałego dla celów ustalania obecności podatkowej przedsiębiorstwa w odpowiedniej jurysdykcji, na podstawie lokalizacji użytkowników i klientów takich firm

    Dendritic Actin Cytoskeleton: Structure, Functions, and Regulations

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    Actin is a versatile and ubiquitous cytoskeletal protein that plays a major role in both the establishment and the maintenance of neuronal polarity. For a long time, the most prominent roles that were attributed to actin in neurons were the movement of growth cones, polarized cargo sorting at the axon initial segment, and the dynamic plasticity of dendritic spines, since those compartments contain large accumulations of actin filaments (F-actin) that can be readily visualized using electron- and fluorescence microscopy. With the development of super-resolution microscopy in the past few years, previously unknown structures of the actin cytoskeleton have been uncovered: a periodic lattice consisting of actin and spectrin seems to pervade not only the whole axon, but also dendrites and even the necks of dendritic spines. Apart from that striking feature, patches of F-actin and deep actin filament bundles have been described along the lengths of neurites. So far, research has been focused on the specific roles of actin in the axon, while it is becoming more and more apparent that in the dendrite, actin is not only confined to dendritic spines, but serves many additional and important functions. In this review, we focus on recent developments regarding the role of actin in dendrite morphology, the regulation of actin dynamics by internal and external factors, and the role of F-actin in dendritic protein trafficking

    FOOD QUALITY MANAGEMENT BASED ON QUALIMETRIC METHODS

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    Fusing best international and local quality management and control practices is one of the most effective ways to gain competitive advantage. Among other things, this includes implementing "customer focus" and "factual decision-making", the key principles of Universal Quality Management, through qualimetric models. The authors have identified qualimtric models with the best quality management potential across the food processing industry, at different product life cycle stages. They especially emphasize the potential of applying qualimetric forecast to food quality and safety. The authors have identified the main stages of product quality metrics forecasting to predict and achieve the desirable food quality in the most effective way possible. The proposed methods are a combination of qualifying methods and world’s best quality management tools and techniques. With the example of quality management in curd products at the development stage the authorship points out the indicators defining product quality and safety, ranks value in building product quality, gives a math formula to describe product quality and an algorithm to assess product quality based on a comprehensive quality indicator and deduce recommendations to achieve desirable and predictable product properties. The proposed stages of qualimetric forecasting, based on the integration of qualimetric models in quality management, have been tested on some curd products in production and proven to be practically effective

    Effects of Tropomodulin 2 on Dendritic Spine Reorganization and Dynamics

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    Dendritic spines are actin-rich protrusions that receive a signal from the axon at the synapse. Remodeling of cytoskeletal actin is tightly connected to dendritic spine morphology-mediated synaptic plasticity of the neuron. Remodeling of cytoskeletal actin is required for the formation, development, maturation, and reorganization of dendritic spines. Actin filaments are highly dynamic structures with slow-growing/pointed and fast-growing/barbed ends. Very few studies have been conducted on the role of pointed-end binding proteins in the regulation of dendritic spine morphology. In this study, we evaluated the role played by tropomodulin 2 (Tmod2)—a brain-specific isoform, on the dendritic spine re-organization. Tmod2 regulates actin nucleation and polymerization by binding to the pointed end via actin and tropomyosin (Tpm) binding sites. We studied the effects of Tmod2 overexpression in primary hippocampal neurons on spine morphology using confocal microscopy and image analysis. Tmod2 overexpression decreased the spine number and increased spine length. Destroying Tpm-binding ability increased the number of shaft synapses and thin spine motility. Eliminating the actin-binding abilities of Tmod2 increased the number of mushroom spines. Tpm-mediated pointed-end binding decreased F-actin depolymerization, which may positively affect spine stabilization; the nucleation ability of Tmod2 appeared to increase shaft synapses.German Academic Exchange ServiceNational Institutes of HealthDeutsche ForschungsgemeinschaftPeer Reviewe

    NCS-1 associates with adenosine A2A receptors and modulates receptor function

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    Modulation of G protein-coupled receptor (GPCR) signaling by local changes in intracellular calcium concentration is an established function of Calmodulin (CaM) which is known to interact with many GPCRs. Less is known about the functional role of the closely related neuronal EF-hand Ca2+-sensor proteins that frequently associate with CaM targets with different functional outcome. In the present study we aimed to investigate if a target of CaM—the A2A adenosine receptor is able to associate with two other neuronal calcium binding proteins (nCaBPs), namely NCS-1 and caldendrin. Using bioluminescence resonance energy transfer (BRET) and co-immunoprecipitation experiments we show the existence of A2A—NCS-1 complexes in living cells whereas caldendrin did not associate with A2A receptors under the conditions tested. Interestingly, NCS-1 binding modulated downstream A2A receptor intracellular signaling in a Ca2+-dependent manner. Taken together this study provides further evidence that neuronal Ca2+-sensor proteins play an important role in modulation of GPCR signaling

    Functional interdependence of the actin regulators CAP1 and cofilin1 in control of dendritic spine morphology

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    The vast majority of excitatory synapses are formed on small dendritic protrusions termed dendritic spines. Dendritic spines vary in size and density that are crucial determinants of excitatory synaptic transmission. Aberrations in spine morphogenesis can compromise brain function and have been associated with neuropsychiatric disorders. Actin filaments (F-actin) are the major structural component of dendritic spines, and therefore, actin-binding proteins (ABP) that control F-actin dis-/assembly moved into the focus as critical regulators of brain function. Studies of the past decade identified the ABP cofilin1 as a key regulator of spine morphology, synaptic transmission, and behavior, and they emphasized the necessity for a tight control of cofilin1 to ensure proper brain function. Here, we report spine enrichment of cyclase-associated protein 1 (CAP1), a conserved multidomain protein with largely unknown physiological functions. Super-resolution microscopy and live cell imaging of CAP1-deficient hippocampal neurons revealed impaired synaptic F-actin organization and dynamics associated with alterations in spine morphology. Mechanistically, we found that CAP1 cooperates with cofilin1 in spines and that its helical folded domain is relevant for this interaction. Moreover, our data proved functional interdependence of CAP1 and cofilin1 in control of spine morphology. In summary, we identified CAP1 as a novel regulator of the postsynaptic actin cytoskeleton that is essential for synaptic cofilin1 activity

    CAP2 dimerization regulates cofilin in synaptic plasticity and Alzheimer's disease

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    Abstract Regulation of actin cytoskeleton dynamics in dendritic spines is crucial for learning and memory formation. Hence, defects in the actin cytoskeleton pathways are a biological trait of several brain diseases, including Alzheimer's Disease. Here, we describe a novel synaptic mechanism governed by the cyclase-associated protein 2 (CAP2), which is required for structural plasticity phenomena and completely disrupted in Alzheimer's Disease. We report that the formation of CAP2 dimers through its Cys32 is important for CAP2 binding to cofilin and for actin turnover. The Cys32-dependent CAP2 homodimerization and association to cofilin are triggered by long-term potentiation and are required for long-term potentiation-induced cofilin translocation into spines, spine remodelling and the potentiation of synaptic transmission. This mechanism is specifically affected in the hippocampus, but not in the superior frontal gyrus, of both Alzheimer's Disease patients and APP/PS1 mice, where CAP2 is down-regulated and CAP2 dimer synaptic levels are reduced. Notably, CAP2 levels in the cerebrospinal fluid are significantly increased in Alzheimer's Disease patients but not in subjects affected by frontotemporal dementia. In Alzheimer's Disease hippocampi, cofilin association to CAP2 dimer/monomer is altered and cofilin is aberrantly localized in spines. Taken together, these results provide novel insights into structural plasticity mechanisms that are defective in Alzheimer's Disease

    Тенденції розвитку національної інноваційної системи в Україні

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    Проаналізовано національну інноваційну систему України. Розглянуто галузі промисловості України за ознаками інноваційної активності та досліджено темпи зростання показників, враховуючи індекс інфляції. Встановлено, що спад темпів зростання динаміки реалізованої продукції призводить до зменшення витрат на інноваційну діяльність.Дан анализ национальной инновационной системы Украины. Рассмотрены отрасли промышленности Украины по признакам инновационной активности и исследованы темпы роста показателей, учитывая индекс инфляции. Установлено, что спад темпов роста динамики реализованной продукции приводит к уменьшению затрат на инновационную деятельность.This article analyses national innovation system of Ukraine. Examined the industry of Ukraine based on innovative activity and investigated the growth indicators, taking into account inflation-index. It is established that the slowdown in the dynamics realized production leads to a decrease in the cost of innovation
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