667 research outputs found
Experimental investigation of the radial structure of energetic particle driven modes
Alfv\'en eigenmodes (AEs) and energetic particle modes (EPMs) are often
excited by energetic particles (EPs) in tokamak plasmas. One of the main open
questions concerning EP driven instabilities is the non-linear evolution of the
mode structure. The aim of the present paper is to investigate the properties
of beta-induced AEs (BAEs) and EP driven geodesic acoustic modes (EGAMs)
observed in the ramp-up phase of off-axis NBI heated ASDEX Upgrade (AUG)
discharges. This paper focuses on the changes in the mode structure of
BAEs/EGAMs during the non-linear chirping phase. Our investigation has shown
that in case of the observed down-chirping BAEs the changes in the radial
structure are smaller than the uncertainty of our measurement. This behaviour
is most probably the consequence of that BAEs are normal modes, thus their
radial structure strongly depends on the background plasma parameters rather
than on the EP distribution. In the case of rapidly upward chirping EGAMs the
analysis consistently shows shrinkage of the mode structure. The proposed
explanation is that the resonance in the velocity space moves towards more
passing particles which have narrower orbit widths.Comment: submitted to Nuclear Fusio
Cephalopod embryonic shells as a tool to reconstruct reproductive strategies in extinct taxa
© 2017 Cambridge Philosophical Society.An exhaustive study of existing data on the relationship between egg size and maximum size of embryonic shells in 42 species of extant cephalopods demonstrated that these values are approximately equal regardless of taxonomy and shell morphology. Egg size is also approximately equal to mantle length of hatchlings in 45 cephalopod species with rudimentary shells. Paired data on the size of the initial chamber versus embryonic shell in 235 species of Ammonoidea, 46 Bactritida, 13 Nautilida, 22 Orthocerida, 8 Tarphycerida, 4 Oncocerida, 1 Belemnoidea, 4 Sepiida and 1 Spirulida demonstrated that, although there is a positive relationship between these parameters in some taxa, initial chamber size cannot be used to predict egg size in extinct cephalopods; the size of the embryonic shell may be more appropriate for this task. The evolution of reproductive strategies in cephalopods in the geological past was marked by an increasing significance of small-egged taxa, as is also seen in simultaneously evolving fish taxa
Activation of learning and creative activity of the vocational pedagogical university students
The relevance of the problem under study is based on the society’s demand for training students - future professional training teachers ready to solve in a creative manner a wide range of professional and pedagogical tasks, as well as to develop professionally-oriented creative work in the process of training; it is also caused by the insufficient extent of the prior research within the vocational training theory of scientific and methodological mechanisms required for implementing this process. The purpose of the article is to develop a conceptual structural model of professionally-oriented learning and creative activity of the vocational pedagogical university students. Leading method for studying this problem is modelling which allows to consider this problem as the process of goaloriented and deliberate acquiring by future professionals the creative approaches to implementation of professional activity. The article presents a structural model of learning and creative activity of vocational pedagogical university students, justifies the necessity to single out in the structure of the students’ learning and creative activity three interconnected components (creative, professional-pedagogical and personal-acmeological), proves the productivity of activating the learning and creative activity of the vocational pedagogical university students by organizing it as quasi-professional process of searching and solving professional tasks which are subjectively and objectively new, on the basis of using synectics including association methods of activating creative thinking integrated into the its structure. The article can be useful for teachers within the vocational and pedagogical education system, as well as for professionals who develop creative abilities of students based on the heuristic creativity methods. © 2016 Krayukhina et al
TUTORING AS A FORM OF PEDAGOGICAL SUPPORT OF STUDENTS’ INDIVIDUAL EDUCATIONAL TRAJECTORIES
Purpose: The key provisions on which the tutor relies on the context of his work are the principles underlying open education: transparency; flexibility; continuity; variability; individual approach; individualization.
Methodology: The relevance of the study is associated with the processes characteristic of the school system in modern Russia (modernization, optimization, change in the structural foundations), as well as the objective need of society in the search for fundamentally new approaches to the content and construction of the educational process in the educational institution.
Result: Tutoring should be considered as a resource of individual evolution of personality, as a form of productive exploitation of open education opportunities for the development of individual educational programs, taking into account the specifics of a particular student. As pedagogical conditions for the implementation of the model of tutor support of the formation of basic school students’ research skills should be considered: innovative educational environment; scientific and methodological provision of tutor support of the process of building basic school students’ research skills; professional skills of the tutor.
Applications: This research can be used for universities, teachers, and students.
Novelty/Originality: In this research, the model of Tutoring as a Form of Pedagogical Support of Students’ Individual Educational Trajectories is presented in a comprehensive and complete manner
Observation of three-dimensional behavior in surface states of bismuth nanowires and the evidence for bulk Bi charge fractionalization
Whereas bulk bismuth supports very-high mobility, light, Dirac electrons and
holes in its interior, its boundaries support a layer of heavy electrons in
surface states formed by spin orbit interaction in the presence of the surface
electric field. Small diameter d trigonal Bi nanowires (30 nm < d < 200 nm)
were studied via magnetotransport at low temperatures and for fields up to 14 T
in order to investigate the role of surfaces in electronic transport. A
two-dimensional behavior was expected for surface charges; however we found
instead a three-dimensional behavior, with a rich spectrum of Landau levels in
a nearly spherical Fermi surface. This is associated with the long penetration
length of surface states of trigonal wires. The prospect of the participation
of surface transport and surface-induced relaxation of bulk carriers in the
electronic properties of macroscopic samples is evaluated. We show that recent
observations of magnetoquantum peaks in the Nernst thermopower coefficient,
attributed to two-dimensional electron gas charge fractionalization, can be
more plausibly interpreted in terms of these surface states.Comment: 14 pages, 3 figure
IRI-2012 MODEL ADAPTABILITY ESTIMATION FOR AUTOMATED PROCESSING OF VERTICAL SOUNDING IONOGRAMS
The paper deals with possibility of IRI-2012 global empirical model applying to the vertical sounding of the ionosphere semiautomatic data processing. Main ionosphere characteristics from vertical sounding data at IZMIRAN Voeikovo station in February 2013 were compared with IRI-2012 model calculation results. 2688 model values and 1866 real values of f0F2, f0E, hmF2, hmE were processed. E and F2 layers critical frequency (f0E, f0F2) and the maximum altitudes (hmF2, hmE) were determined from the ionograms. Vertical profiles of the electron concentration were restored with IRI-2012 model by measured frequency and height. The model calculation was also made without the inclusion of the real vertical sounding data. Monthly averages and standard deviations (σ) for the parameters f0F2, f0E, hmF2, hmE for each hour of the day were calculated according to the vertical sounding and model values. Model applicability conditions for automated processing of ionograms for subauroral ionosphere were determined. Initial IRI-2012 model can be applied in the sub-auroral ionograms processing at daytime with undisturbed conditions in the absence of sporadic ionization. In this case model calculations can be adjusted by the near-time vertical sounding data. IRI-2012 model values for f0E (in daytime) and hmF2 can be applied to reduce computational costs in the systems of automatic parameters search and preliminary determination of the searching area range for the main parameters. IRI-2012 model can be used for a more accurate approximation of the real data series in the absence of the real values. In view of sporadic ionization, ionosphere models of the high latitudes must be applied with corpuscular ions formation unit
Twenty-year changes in the clinical and echocardiographic characteristics of patients with early postinfarction remodeling after primary ST-segment elevation myocardial infarction
Aim. To compare structural and functional left ventricular (LV) changes in the early period of myocardial infarction (MI) within 20 years on the basis of the Emergency Cardiology Department of the Cardiology Research Institute (Tomsk).Material and methods. The study included two groups of patients who were treated at different periods of time with an interval of 20 years. Group 1 included 83 patients who had ST-segment elevation MI (STEMI) in 1997-1999, while group 2 — 83 patients with STEMI from 2019-2020. Echocardiography was performed during the first 72 hours from hospitalization and on the 7-10th day. Depending on the increase in LV end-diastolic volume (EDV) by >15% by the 7-10th day, the patients were divided into 2 subgroups: with remodeling (LVR+) and without remodeling (LVR-).Results. Patients of the 2nd group were older, with a larger proportion of females and with a high incidence of risk factors for coronary artery disease compared with patients of the 1st group. In the early postinfarction period among patients of the 2nd group, acute LV aneurysm, early postinfarction angina and Dressler syndrome developed less frequently. The proportion of adverse LV remodeling in patients of the 1st group was higher (32,8% vs 17%), and while the percentage of reverse remodeling was lower (10% vs 24%), p<0,05. Comparison of the absolute values of LV EDV, end-systolic volume (ESV) and ejection fraction (EF) at baseline and after 7 days, as well as their increase showed higher intensity of post-infarction remodeling in group 1 patients. In patients of the 1st group, there was a progression of LV remodeling (Me ΔEDV — 12,2%) with a deterioration in LV contractility by the 7th day (Me ΔESV — 14%), while in patients of the 2nd group during the first 7 days of MI, there were more stable LV EDV and ESV (p>0,05) and an increase in LVEF (p=0,03) before discharge.Conclusion. In the present era of primary percutaneous coronary intervention and pharmacological treatment of MI, early adverse LV remodeling develops less frequently and is characterized by less pronounced left heart dilatation
Dialectics and Implications of Natural Neurotropic Autoantibodies in Neurological Disease and Rehabilitation
The role of natural idiotypic (Id-Abs) and anti-idiotypic (AId-Abs) autoantibodies
against neuro-antigens observed in different neurological disorders is not fully
understood. In particular, limited experimental evidence has been provided
concerning the qualitative and quantitative serological response after acute injuries
of the central nervous system or during chronic mental diseases. In this study, we
analyzed the specific Id-Abs and AId-Abs serological reactivities against 4
neuro-antigens in a large population of patients with ischemic stroke, schizophrenia,
as well as healthy individuals. Patients with ischemic stroke were tested at different
time points following the acute stroke episode and a correlation was attempted
between autoantibodies response and different patterns of functional recovery.
Results showed variable and detectable Id-Abs and AId-Abs in different proportions
of all three populations of subjects. Among patients with different functional
recovery after ischemic stroke, a difference in time-related trends of Id-Abs and
AId-Abs was encountered. Our observations suggest that changes in
the production of natural neurotropic Abs may engender a positive homeostatic,
beside a possible
pathogenic effect, in specific neurological disorders
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