748 research outputs found
Vibration technology research achievements of the Mekhanobr scientific school and their practical implementation
A brief overview of the achievements of the Mekhanobr Institute in the field of the theory and design of vibration processes and machines is given. The main theoretical works cover the discovery and development of the theory of self-synchronization of rotating bodies, the development of the theory of vibrational displacement, the creation of new analytical approaches to studying the effects of vibration on nonlinear systems and media – vibrational mechanics and vibrational rheology; the discovery and research into a number of nonlinear vibration effects, the development of the theory of vibrational classification. The main applied developments include the creation of a new class of highly efficient vibration machines (crushers, screens, separators, flotation machines, etc.), the development of respective design methods, the creation of a set of laboratory vibration equipment and a unique experimental base. The developments of recent years are considered in detail
Running economy and cytokines: what the influence of IL-6 and IL-10?
Introduction: During the exercise performing the muscle produce cytokines, named “myokines”. These molecules show autocrine, paracrine and endocrine effects. One of them IL-6 demonstrates both pro and anti-inflammatory actions. Usually they have an anti-inflammatory action when produced by working muscles and when produced by other tissues, especially adipose, they assume a pro-inflammatory profile. Athletes´ performance, especially those that run long distances races (endurance) is associated with higher levels of maximal oxygen uptake (VO2max). Running economy (RE) is a methodology used to evaluate the performance of runners and is defined as the rate of oxygen consumption (VO2) required for maintain a specific speed . RE is determined by the energy cost of running (Cr), which is the energy required to transport body mass in a specific running speed (km/h). Despite some studies demonstrated the importance of RE in a performance of athletes, there is no studies relating running economy and cytokines. The aim of this study was to investigate the correlation between cytokine profile and running economy. Subjects: Twenty-two male recreational runners living in the city of São Paulo were recruited for the study that had been approved by the UNIFESP-EPM Ethics Committee. None of the participants were using lipid-lowering medications, no smokers, addicted to alcohol consumption, obese or had systemic arterial hypertension, neither liver, renal, metabolic, inflammatory or neoplastic diseases. Methods: Blood sample was collected at rest. Blood draw for all the individuals was performed after 12 hours of fasting. IL-6 and IL-10 were measured by ELISA in serum. Statistics: Pearson’s correlation coefficient was used to identify a correlation between Running Economy (RE) and cytokine levels. The significance level was set to 5% (p \u3c 0.05). Results and Discussion: In the group of athletes studied we found that a significant correlation between RE and IL-6 (figure 1A), showing that runners with better RE presented decreased IL-6 levels. However, no correlation was observed in relation to IL-10 levels and RE (Figure 1B). Previously we demonstrated that pro-inflammatory cytokines influences negatively the VO2max that is used to calculate the aerobic capacity. So, we assumed that athletes with more time and volume of training would have lower levels of IL-6 which in our results is associated to greater RE. However, we couldn´t find any correlation between these parameters
On the nature of the solar-wind-Mars interaction
Plasma measurements near Mars on the U.S.S.R. Mars-2, -3, and -5 spacecraft are considered. The data are compared with simultaneous magnetic measurements. Strong evidence is obtained in favor of a direct interaction and mass exchange between the solar wind plasma and the gaseous envelope of Mars
Structure of Cosmic Ray-modified Perpendicular Shocks
Kinetic diffusion of cosmic rays ahead of perpendicular shocks induces charge
non-neutrality, which is mostly, yet not completely, screened by the bulk
plasma via polarization drift current. Hydrodynamic shear instabilities as well
as modified Buneman instability of the polarization current generate the
turbulence necessary for a Fermi-type acceleration. Thus, similar to the case
of parallel shocks, in perpendicular shocks the diffusing cosmic rays generate
unstable plasma currents that in turn excite turbulence. This allows a
self-consistent evolution of a shock-cosmic rays system. In the kinetic regime
of the modified Buneman instability, electrons may be heated in the cosmic ray
precursor.Comment: 12 pages, 1 Fi
Simulation of the Neutral Particle Converter of the ARIES-L Device
AbstractThis paper presents the concept of Lunar regolith surface layer composition analysis using solar wind bombardment and registration of the sputtered and knocked out atoms converted into ions with solid-state converters and subsequent registration of ions by high-aperture electrostatic analyzer. Monte Carlo binary collision approximation code is used to calculate angular and energy distributions of scattered and sputtered atoms. Literature data are used for evaluation of charged fractions of scattered and sputtered components and SIMION code is used for calculation of charged particles trajectories in electrostatic deflector. The total sensitivity of the proposed scheme is evaluated
Auto anti oxLDL, IgM and IgG: comparison between sedentary and athletes
Introduction: The practice of regular physical activity contributes to reduce the prevalence of coronary hearth disease (CHD) and aerobic exercises are associated with beneficial changes in the profile of circulating lipids and lipoproteins. However in the past years the oxidative hypothesis assumed great importance in the pathogenesis of CHD. During exhaustive exercises there is a greater possibility of oxidation of LDL, forming oxidized LDL (oxLDL) that has a key role in atherogenesis. However the incidence of coronary events in athletes is lower than in sedentary persons. It is described in the literature that we can found in serum auto autoantibodies anti-oxLDL, of the isotypes IgG and IgM. The former involved with atherogenesis and the latter with an atheroprotective function. The aim of this study was to verify if there are differences in the prevalence of the different autoantibodies between athletes and sedentary persons. Methods: Twenty male recreational runners and twenty male sedentary individuals living in the city of São Paulo were recruited for the study. Both the study protocol and consent form had been approved by the UNIFESP-EPM Ethics Committee. None of the participants were using lipid-lowering medications, no smokers, addicted to alcohol consumption, obese or had systemic arterial hypertension, neither liver, renal, metabolic, inflammatory or neoplastic diseases. Blood sample were collected at rest. Blood draws for all the individuals were performed after 12 hours of fasting. IgM and IgG anti ox LDL specific reactivity in serum, were measured by ELISA using previously stored serum. Student’s t-test was used to analyze differences in age and body mass index (BMI). The Mann-Whitney test was used to determine if the differences between the results for sedentary individuals and those for runners at rest were significant. Results: We found that at rest the group of athletes studied showed a statistically higher concentration of IgM autoantibodies against ox-LDL than controls (figure 1 a). At the same time, IgG autoantibodies anti ox-LDL presented the same concentration in controls and athletes (Figure 1 b). Conclusion: This finding is of extreme importance when we consider the prevalence of CHD in those different populations and the opposite actions of these two isotypes of antibodies
Exercise influence on immune response
ABSTRACT The study of the influence of exercise on immune response is a field in constant grow since the 1970s. The main areas studied are infection of upper respiratory airways in athletes submitted to extenuating exercises, the exercise as a model of stress and the effects of training as an adaptive mechanism to cope with stress. Exercise promotes an imbalance in organic homeostasis, and all of the systems, including the immune system, must adequate their function to this new situation. The responses to exercise can be expressed as acute response, a transitory response to stress and chronic adaptive response, when training provides better conditions for the organism to cope with stress. In both situations the components of the immune system, the cellular and humoral arms of the innate and adaptive systems, are affected by exercise. Not as a rule, one can say that moderate exercise is associated with a better function of the immune system and high intensity exercise in stressful situations is associated with a transitory state of immunodepression.RESUMO O estudo da relação entre o exercĂcio e a resposta imune teve grande impulso a partir da metade da dĂ©cada de 70, tendo como principais áreas de interesse o estudo da infecção de vias aĂ©reas superiores em atletas submetidos a grandes esforços, o exercĂcio como modelo de estresse e a resposta do treinamento como resposta adaptativa frente a situações de estresse. A descrição da interação entre os sistemas imune e neuroendĂłcrino foi de importância capital no desenvolvimento desses estudos. O exercĂcio gerando um desvio da homeostase orgânica leva Ă reorganização das respostas de diversos sistemas, entre eles o sistema imune. É adequado dividir a resposta ao exercĂcio em resposta aguda, resposta transitĂłria ao estresse e resposta de adaptação crĂ´nica, na qual o treinamento capacita o organismo a lidar com o estĂmulo estressante de maneira mais adequada. Ambas as respostas afetam os diversos componentes do sistema imune, tanto a resposta inata em seu componente celular compreendendo neutrĂłfilos, macrĂłfagos e cĂ©lulas natural killer, como em seu componente humoral, proteĂnas de fase aguda, sistema do complemento e enzimas, como o sistema imune adaptativo, em seu componente celular (linfĂłcitos T e B), como no componente humoral (anticorpos e citocinas). Apesar das incorreções que cometemos quando das generalizações, podemos dizer que, de modo geral, o exercĂcio de intensidade moderada, praticado com regularidade, melhora a capacidade de resposta do sistema imune, enquanto o exercĂcio de alta intensidade praticado sob condições estressantes provoca um estado transitĂłrio de imunodepressĂŁo.Universidade de SĂŁo Paulo Instituto de Ciencias Biologicas Departamento de HistologiaUniversidade Federal de SĂŁo Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Disciplina de ImunologiaUNIFESP, EPM, Disciplina de ImunologiaSciEL
The Structure of Martian Magnetosphere at the Dayside Terminator Region as Observed on MAVEN Spacecraft
We analyzed 44 passes of the MAVEN spacecraft through the magnetosphere,
arranged by the angle between electric field vector and the projection of
spacecraft position radius vector in the YZ plane in MSE coordinate system
( E ). All passes were divided into 3 angular sectors near 0{\deg},
90{\deg} and 180{\deg} E angles in order to estimate the role of IMF
direction in plasma and magnetic properties of dayside Martian magnetosphere.
The time interval chosen was from January 17 through February 4, 2016 when
MAVEN was crossing the dayside magnetosphere at SZA ~ 70{\deg}. Magnetosphere
as the region with prevailing energetic planetary ions is always found between
the magnetosheath and the ionosphere. 3 angular sectors of dayside interaction
region in MSE coordinate system with different orientation of the solar wind
electric field vector E = -1/c V x B showed that for each sector one can find
specific profiles of the magnetosheath, the magnetic barrier and the
magnetosphere. Plume ions originate in the northern MSE sector where motion
electric field is directed from the planet. This electric field ejects
magnetospheric ions leading to dilution of magnetospheric heavy ions
population, and this effect is seen in some magnetospheric profiles. Magnetic
barrier forms in front of the magnetosphere, and relative magnetic field
magnitudes in these two domains vary. The average height of the boundary with
ionosphere is ~530 km and the average height of the magnetopause is ~730 km. We
discuss the implications of the observed magnetosphere structure to the
planetary ions loss mechanism.Comment: 24 pages, 13 figure
Review of the monograph “The Arctic: a Development Strategy”
The review emphasizes the key features of the monograph “The Arctic: Development Strategy”, prepared by experts of the Council for the Study of Productive Forces of the Ministry of Economic Development of Russia and NArFU named after M.V. Lomonosov. The authors developed a systematic analysis of the development issues of the Russian Arctic and the state development efforts in this macro-region. They studied the preferential regimes of economic activities and the role of mineral resource centers as important drivers of socio-economic development. According to the reviewer, the monograph is of interest both to specialists and to a wide range of readers
- …