2,683 research outputs found

    Yuri A. Ovchinnikov

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    A new clinical tool for assessing numerical abilities in neurological diseases: numerical activities of daily living

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    The aim of this study was to build an instrument, the numerical activities of daily living (NADL), designed to identify the specific impairments in numerical functions that may cause problems in everyday life. These impairments go beyond what can be inferred from the available scales evaluating activities of daily living in general, and are not adequately captured by measures of the general deterioration of cognitive functions as assessed by standard clinical instruments like the MMSE and MoCA. We assessed a control group (n = 148) and a patient group affected by a wide variety of neurological conditions (n = 175), with NADL along with IADL, MMSE, and MoCA. The NADL battery was found to have satisfactory construct validity and reliability, across a wide age range. This enabled us to calculate appropriate criteria for impairment that took into account age and education. It was found that neurological patients tended to overestimate their abilities as compared to the judgment made by their caregivers, assessed with objective tests of numerical abilities

    Processing of semantic and grammatical gender in Spanish speakers with aphasia

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    Published online: 30 May 2021.Background: Previous studies have argued that there are two types of linguistic gender: grammatical gender, which is arbitrarily assigned to nouns, and semantic gender, which depends on the gender of the referent. Aim: We explore the hypothesis that these two types of gender entail distinct cognitive processes by investigating the performance of people with aphasia at the level of sentence processing. Methods and Procedure: Nine people with aphasia (seven with fluent aphasia) and a control group of thirteen age-matched healthy participants took part in a constrained completion choice task. The participants had to complete sentences in a way that made the last word gender congruent. The subjects of the sentences had either Semantic gender (enfermera, nurse; indicating the gender of the referent), Grammatical gender (silla, chair), or Opaque-Grammatical gender (tomate, tomato). Results: People with aphasia performed more poorly in all gender conditions than healthy controls. They also were less accurate in both the Grammatical and Opaque-Grammatical conditions than in the Semantic gender condition. Conclusion: We propose that because semantic gender provides more salient information, it is processed faster than grammatical gender.MC was supported by the postdoctoral RamĂłn y Cajal fellowship (RYC-2013-14013), Agencia Estatal de InvestigaciĂłn (AEI, National Research Agency), and Fondo Europeo de Desarrollo Regional (FEDER, European Regional Development Fund) under projects PSI2017-87784-R and RED2018- 102615-T

    Maturation of human lactase-phlorizin hydrolase Proteolytic cleavage of precursor occurs after passage through the Golgi complex

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    AbstractMaturation of human intestinal lactase-phlorizin hydrolase (LPH) requires that a precursor (pro-LPH) be proteolytically processed to the mature microvillus membrane enzyme (m-LPH). The subcellular site of this processing is unknown. Using low-temperature experiments and brefeldin A (BFA), intracellular transport was blocked in intestinal epithelial cells. In Caco-2 cells incubated at 18°C pro-LPH was complex-glycosylated but not cleaved, while at 20°C small amounts of proteolytically processed LPH were observed. These data exclude a pre-Golgi proteolytic event. BFA completely blocked proteolytic maturation of LPH and lead to an aberrant form of pro-LPH in both Caco-2 cells and intestinal explants. Therefore, proteolytic processing of LPH is a post-Golgi event, occuring either in the trans-Golgi network, transport vesicles, or after insertion of pro-LPH into the microvillus membrane

    Understanding person acquisition using an interactive activation and competition network

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    Face perception is one of the most developed visual skills that humans display, and recent work has attempted to examine the mechanisms involved in face perception through noting how neural networks achieve the same performance. The purpose of the present paper is to extend this approach to look not just at human face recognition, but also at human face acquisition. Experiment 1 presents empirical data to describe the acquisition over time of appropriate representations for newly encountered faces. These results are compared with those of Simulation 1, in which a modified IAC network capable of modelling the acquisition process is generated. Experiment 2 and Simulation 2 explore the mechanisms of learning further, and it is demonstrated that the acquisition of a set of associated new facts is easier than the acquisition of individual facts in isolation of one another. This is explained in terms of the advantage gained from additional inputs and mutual reinforcement of developing links within an interactive neural network system. <br/

    Cellular adaptation to low oxygen availability by a switch in the protein synthesis machinery

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    Protein synthesis is a classic molecular mechanism of cell biology that is taught in introductory biology classrooms. It involves the translation of messenger ribonucleic acid (mRNA) information into proteins, the building blocks of life. The initial step of protein synthesis consists of the euÂŹkaryotic translation initiation factor 4E (eIF4E) binding to the 5’cap of mRNAs. A variety of stressÂŹes repress translation to conserve energy because protein synthesis requires over half of a cell’s energy supply. An important stress for multicellular animals is low oxygen availability (hypoxia). This causes a repression of cap-directed translation by inhibiting eIF4E. This raises a fundamental question in cell biology as to how proteins are synthesized in periods of oxygen scarcity and eIF4E inhibition. Here, we describe an oxygen-regulated translation initiation complex that mediates selective cap-dependent protein synthesis. Hypoxia stimulates the formation of a complex that inÂŹcludes the oxygen-regulated hypoxia-inducible factor 2α (HIF-2α), the RNA binding protein RBM4 and the cap-binding eIF4E2, an eIF4E homologue. We also identified an RNA hypoxia response eleÂŹment (rHRE) that recruits this complex to a wide array of mRNAs, including the epidermal growth factor receptor (EGFR), which plays a role in growth signaling and proliferation. Once assembled at the rHRE, HIF-2α/RBM4/eIF4E2 captures the 5’cap and targets mRNAs for active translation thereby evading hypoxia-induced repression of protein synthesis. These findings demonstrate that cells have evolved a program whereby oxygen availability switches the basic translation initiation machinery.

    Climate change and climate variability: personal motivation for adaptation and mitigation

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    BACKGROUND: Global climate change impacts on human and natural systems are predicted to be severe, far reaching, and to affect the most physically and economically vulnerable disproportionately. Society can respond to these threats through two strategies: mitigation and adaptation. Industry, commerce, and government play indispensable roles in these actions but so do individuals, if they are receptive to behavior change. We explored whether the health frame can be used as a context to motivate behavioral reductions of greenhouse gas emissions and adaptation measures. METHODS: In 2008, we conducted a cross-sectional survey in the United States using random digit dialing. Personal relevance of climate change from health threats was explored with the Health Belief Model (HBM) as a conceptual frame and analyzed through logistic regressions and path analysis. RESULTS: Of 771 individuals surveyed, 81% (n = 622) acknowledged that climate change was occurring, and were aware of the associated ecologic and human health risks. Respondents reported reduced energy consumption if they believed climate change could affect their way of life (perceived susceptibility), Odds Ratio (OR) = 2.4 (95% Confidence Interval (CI): 1.4-4.0), endanger their life (perceived severity), OR = 1.9 (95% CI: 1.1-3.1), or saw serious barriers to protecting themselves from climate change, OR = 2.1 (95% CI: 1.2-3.5). Perceived susceptibility had the strongest effect on reduced energy consumption, either directly or indirectly via perceived severity. Those that reported having the necessary information to prepare for climate change impacts were more likely to have an emergency kit OR = 2.1 (95% CI: 1.4-3.1) or plan, OR = 2.2 (95% CI: 1.5-3.2) for their household, but also saw serious barriers to protecting themselves from climate change or climate variability, either by having an emergency kit OR = 1.6 (95% CI: 1.1-2.4) or an emergency plan OR = 1.5 (95%CI: 1.0-2.2). CONCLUSIONS: Motivation for voluntary mitigation is mostly dependent on perceived susceptibility to threats and severity of climate change or climate variability impacts, whereas adaptation is largely dependent on the availability of information relevant to climate change. Thus, the climate change discourse could be framed from a health perspective to motivate behaviour change
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