863 research outputs found

    The impact of sleep quality on cognitive functioning in Parkinson's disease

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    In healthy individuals and those with insomnia, poor sleep quality is associated with decrements in performance on tests of cognition, especially executive function. Sleep disturbances and cognitive deficits are both prevalent in Parkinson's disease (PD). Sleep problems occur in over 75% of patients, with sleep fragmentation and decreased sleep efficiency being the most common sleep complaints, but their relation to cognition is unknown. We examined the association between sleep quality and cognition in PD. In 35 non-demented individuals with PD and 18 normal control adults (NC), sleep was measured using 24-hr wrist actigraphy over 7 days. Cognitive domains tested included attention and executive function, memory and psychomotor function. In both groups, poor sleep was associated with worse performance on tests of attention/executive function but not memory or psychomotor function. In the PD group, attention/executive function was predicted by sleep efficiency, whereas memory and psychomotor function were not predicted by sleep quality. Psychomotor and memory function were predicted by motor symptom severity. This study is the first to demonstrate that sleep quality in PD is significantly correlated with cognition and that it differentially impacts attention and executive function, thereby furthering our understanding of the link between sleep and cognition.Published versio

    The impact of sleep quality on cognitive functioning in Parkinson's disease

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    In healthy individuals and those with insomnia, poor sleep quality is associated with decrements in performance on tests of cognition, especially executive function. Sleep disturbances and cognitive deficits are both prevalent in Parkinson's disease (PD). Sleep problems occur in over 75% of patients, with sleep fragmentation and decreased sleep efficiency being the most common sleep complaints, but their relation to cognition is unknown. We examined the association between sleep quality and cognition in PD. In 35 non-demented individuals with PD and 18 normal control adults (NC), sleep was measured using 24-hr wrist actigraphy over 7 days. Cognitive domains tested included attention and executive function, memory and psychomotor function. In both groups, poor sleep was associated with worse performance on tests of attention/executive function but not memory or psychomotor function. In the PD group, attention/executive function was predicted by sleep efficiency, whereas memory and psychomotor function were not predicted by sleep quality. Psychomotor and memory function were predicted by motor symptom severity. This study is the first to demonstrate that sleep quality in PD is significantly correlated with cognition and that it differentially impacts attention and executive function, thereby furthering our understanding of the link between sleep and cognition.Published versio

    "Oxygen sensing" by Na,K-ATPase: These miraculous thiols

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    Control over the Na,K-ATPase function plays a central role in adaptation of the organisms to hypoxic and anoxic conditions. As the enzyme itself does not possess O2 binding sites its "oxygen-sensitivity" is mediated by a variety of redox-sensitive modifications including S-glutathionylation, S-nitrosylation, and redox-sensitive phosphorylation. This is an overview of the current knowledge on the plethora of molecular mechanisms tuning the activity of the ATP-consuming Na,K-ATPase to the cellular metabolic activity. Recent findings suggest that oxygen-derived free radicals and H2O2, NO, and oxidized glutathione are the signaling messengers that make the Na,K-ATPase "oxygen-sensitive." This very ancient signaling pathway targeting thiols of all three subunits of the Na,K-ATPase as well as redox-sensitive kinases sustains the enzyme activity at the "optimal" level avoiding terminal ATP depletion and maintaining the transmembrane ion gradients in cells of anoxia-tolerant species. We acknowledge the complexity of the underlying processes as we characterize the sources of reactive oxygen and nitrogen species production in hypoxic cells, and identify their targets, the reactive thiol groups which, upon modification, impact the enzyme activity. Structured accordingly, this review presents a summary on (i) the sources of free radical production in hypoxic cells, (ii) localization of regulatory thiols within the Na,K-ATPase and the role reversible thiol modifications play in responses of the enzyme to a variety of stimuli (hypoxia, receptors' activation) (iii) redox-sensitive regulatory phosphorylation, and (iv) the role of fine modulation of the Na,K-ATPase function in survival success under hypoxic conditions. The co-authors attempted to cover all the contradictions and standing hypotheses in the field and propose the possible future developments in this dynamic area of research, the importance of which is hard to overestimate. Better understanding of the processes underlying successful adaptation strategies will make it possible to harness them and use for treatment of patients with stroke and myocardial infarction, sleep apnoea and high altitude pulmonary oedema, and those undergoing surgical interventions associated with the interruption of blood perfusion.The review was funded by the grants of Swiss Nationa lScience Foundation IZK0Z3_157269/1 and 310030_124970/1 to AB and Russian Science Foundation (Grant#14-14-01152) to IP Spanish Government grants (partially funded by the European Union FEDER/EDRF) PI12/00875 and PI15/00107 and a grant from the Fundación Domingo Martínez are supporting AM, PH received a travel grant from the Instituto de Investigación Sanitaria Princesa (to PH),and by COST actions TD0901 (HypoxiaNet) and CM1001. PH is recipient of a pre-doctoral FPU fellowship from the Spanish Government and AM is supported by the I3SNS programme (ISCIII, Spanish Government, partially funded by FEDER/ERDF

    Pivotal Role of Reduced Glutathione in Oxygen-induced Regulation of the Na + /K + Pump in Mouse Erythrocyte Membranes

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    This study addresses the mechanisms of oxygen-induced regulation of ion transport pathways in mouse erythrocyte, specifically focusing on the role of cellular redox state and ATP levels. Mouse erythrocytes possess Na+/K+ pump, K+-Cl− and Na+-K+-2Cl− cotransporters that have been shown to be potential targets of oxygen. The activity of neither cotransporter changed in response to hypoxia-reoxygenation. In contrast, the Na+/K+ pump responded to hypoxic treatment with reversible inhibition. Hypoxia-induced inhibition was abolished in Na+-loaded cells, revealing no effect of O2 on the maximal operation rate of the pump. Notably, the inhibitory effect of hypoxia was not followed by changes in cellular ATP levels. Hypoxic exposure did, however, lead to a rapid increase in cellular glutathione (GSH) levels. Decreasing GSH to normoxic levels under hypoxic conditions abolished hypoxia-induced inhibition of the pump. Furthermore, GSH added to the incubation medium was able to mimic hypoxia-induced inhibition. Taken together these data suggest a pivotal role of intracellular GSH in oxygen-induced modulation of the Na+/K+ pump activit

    Cluster observations of the midaltitude cusp under strong northward interplanetary magnetic field

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    We report on a multispacecraft cusp observation lasting more than 100 min. We determine the cusp boundary motion and reveal the effect on the cusp size of the interplanetary magnetic field (IMF) changing from southward to northward. The cusp shrinks at the beginning of the IMF rotation and it reexpands at the rate of 0.40° invariant latitude per hour under stable northward IMF. On the basis of plasma signatures inside the cusp, such as counterstreaming electrons with balanced fluxes, we propose that pulsed dual lobe reconnection operates during the time of interest. SC1 and SC4 observations suggest a long-term regular periodicity of the pulsed dual reconnection, which we estimate to be ~1–5 min. Further, the distances from the spacecraft to the reconnection site are estimated on the basis of observations from three satellites. The distance determined using SC1 and SC4 observations is ~15 RE and that determined from SC3 data is ~8 RE. The large-scale speed of the reconnection site sunward motion is ~16 km s-1. We observe also a fast motion of the reconnection site by SC1, which provides new information about the transitional phase after the IMF rotation. Finally, a statistical study of the dependency of plasma convection inside the cusp on the IMF clock angle is performed. The relationship between the cusp stagnation, the dual lobe reconnection process, and the IMF clock angle is discussed

    Development of methods ensuring balanced budgets in the medium term

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    Purpose: The study aims to identify the prospects for the application of modern methods of balancing the budgets of the constituent entities of the Russian Federation. Design/Methodology/Approach: The formation of balanced budgets of the constituent entities of the Russian Federation is intended to provide funding for priority expenditures of the regions effectively, predetermining the need to identify the features of the implementation of scientific theories about the balance of budgets, to highlight the problems of the budget legislation of the Russian Federation and to determine the prospects for the use of traditional and new market methods of regulating the basic parameters of budgets. Findings: Authors grounded the need for complex application of methods of balancing budgets for the main parameters to increase tax and non-tax revenues, the formation of expenses regarding their optimization and efficiency, weighted debt policy, improving intergovernmental relations. The authors recommended the development of standards for applying methods of balancing budgets. Practical implications: The results of the study can be considered in the practice of forming the basic parameters of the budgets of the constituent entities of the Russian Federation in the context of limited budget funds to strengthen budget revenues. Originality/Value: The main contribution of this study is to justify the complexity of the application of methods of balancing budgets, as well as to shift the emphasis on the regulation of domestic debt relations in the context of economic uncertainty.peer-reviewe

    Pension fund of the Russian Federation : challenges and prospects of the development under modern conditions

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    The article states that it is necessary to develop new, flexible basis to introduce digital technologies into the Russian Pension Fund activity. Openness, subordination and results of the social services implementation provided by the Pension Fund of The Russian Federation must ensure transparency, accessibility for the Russian citizens to get services of the Pension Fund of The Russian Federation electronically as well as transparent activity of the bodies of the Pension Fund of The Russian Federation. The goal of the article is to research the Pension Fund of The Russian Federation activity in terms of the effective management of its financial resources through introduction of the new automated information system. To meet this objective the following tasks are set: to reveal historic aspects of the Pension Fund of The Russian Federation creation and development; single out current challenges and propose the directions to improve activity of the bodies of the Pension Fund of The Russian Federation. The conclusions about the necessity of the Pension Fund of The Russian Federation active work in the frame of interdepartmental electronic interaction with key federal agencies and executive authorities of all subjects of the Russian Federation to improve the management quality and control over the Russian Pension Fund’s financial resources.peer-reviewe

    Conceptual approaches in providing the effective and responsible management of state programs management

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    The article proves that state programs turn to be the basic tool for increasing the effectiveness of budget expenditures within the framework of program-targeted budget planning and forecasting framework. Obligatory conditions for openness, departmentalism, and effectiveness of state programs implementation correspond to the need to ensure the transparency of budget procedures and openness of authorities’ activities. The article is aimed at studying the conceptual approaches of executive bodies in ensuring the effective management of state programs including disclosure of the specifics of the development of state programs, increasing their effectiveness and monitoring the use of budgetary funds on the basis of finding a balance between the increasingly complicated tasks of the state budget policy and the established budgetary opportunities. To achieve the goal, the following objectives are set: revealing methodological approaches to the formation of state programs; suggesting ways to improve the evaluation of state programs effectiveness at all stages of the budget process on the basis of the system of indicators; outlining the prospects for planning and financing state programs. The article suggests conclusions on the improving the quality of management and control of state programs as an obligatory condition for effective and responsible management of budgetary funds.peer-reviewe

    Search for Low Mass Exotic mesonic structures. Part II: attempts to understand the experimental results

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    Our previous paper, part I of the same study, shows the different experimental spectra used to conclude on the genuine existence of narrow, weakly excited mesonic structures, having masses below and a little above the pion (M=139.56 MeV) mass. This work \cite{previous} was instigated by the observation, in the Σ+\Sigma^{+} disintegration: Σ+→\Sigma^{+}\topP0^{0}, P0→μ−μ+^{0}\to\mu^{-}\mu^{+} \cite{park}, of a narrow range of dimuon masses. The authors conclude on the existence of a neutral intermediate state P0_{0}, with a mass M=214.3 MeV ±\pm 0.5 MeV. We present here some attempts to understand the possible nature of the structures observed in part I.Comment: 3 pages, 4 figures. Follows 0710.1796. Both replace arXiv:0707.1261 [nucl-ex

    Statistical study of the location and size of the electron edge of the Low-Latitude Boundary Layer as observed by Cluster at mid-altitudes

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    The nature of particle precipitations at dayside mid-altitudes can be interpreted in terms of the evolution of reconnected field lines. Due to the difference between electron and ion parallel velocities, two distinct boundary layers should be observed at mid-altitudes between the boundary between open and closed field lines and the injections in the cusp proper. At lowest latitudes, the electron-dominated boundary layer, named the "electron edge" of the Low-Latitude Boundary Layer (LLBL), contains soft-magnetosheath electrons but only high-energy ions of plasma sheet origin. A second layer, the LLBL proper, is a mixture of both ions and electrons with characteristic magnetosheath energies. The Cluster spacecraft frequently observe these two boundary layers. We present an illustrative example of a Cluster mid-altitude cusp crossing with an extended electron edge of the LLBL. This electron edge contains 10–200 eV, low-density, isotropic electrons, presumably originating from the solar wind halo population. These are occasionally observed with bursts of parallel and/or anti-parallel-directed electron beams with higher fluxes, which are possibly accelerated near the magnetopause X-line. We then use 3 years of data from mid-altitude cusp crossings (327 events) to carry out a statistical study of the location and size of the electron edge of the LLBL. We find that the equatorward boundary of the LLBL electron edge is observed at 10:00–17:00 magnetic local time (MLT) and is located typically between 68° and 80° invariant latitude (ILAT). The location of the electron edge shows a weak, but significant, dependence on some of the external parameters (solar wind pressure, and IMF <i>B<sub>Z</sub></i>- component), in agreement with expectations from previous studies of the cusp location. The latitudinal extent of the electron edge has been estimated using new multi-spacecraft techniques. The Cluster tetrahedron crosses the electron and ion boundaries of the LLBL/cusp with time delays of 1–40 min between spacecraft. We reconstruct the motion of the electron boundary between observations by different spacecraft to improve the accuracy of the estimation of the boundary layer size. In our study, the LLBL electron edge is distinctly observed in 87% of mid-altitude LLBL/cusp crossings with clear electron and ion equatorward boundaries equivalent to 35% of all LLBL/cusp crossings by Cluster. The size of this region varied between 0°–2° ILAT with a median value of 0.2° ILAT. Generally, the size of the LLBL electron edge depends on the combination of many parameters. However, we find an anti-correlation between the size of this region and the strength of the IMF, the absolute values of the IMF <i>B<sub>Y</sub></i>- and <i>B<sub>Z</sub></i>-components and the solar wind dynamic pressure, as is expected from a simple reconnection model for the origin of this region
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