3,420 research outputs found
Subsquares Approach - Simple Scheme for Solving Overdetermined Interval Linear Systems
In this work we present a new simple but efficient scheme - Subsquares
approach - for development of algorithms for enclosing the solution set of
overdetermined interval linear systems. We are going to show two algorithms
based on this scheme and discuss their features. We start with a simple
algorithm as a motivation, then we continue with a sequential algorithm. Both
algorithms can be easily parallelized. The features of both algorithms will be
discussed and numerically tested.Comment: submitted to PPAM 201
Comparison of solar activity proxies: eigen vectors versus averaged sunspot numbers
We attempt to establish links between a summary curve, or modulus summary
curve, MSC, of the solar background magnetic field (SBMF) derived from
Principal Component Analysis, with the averaged sunspot numbers (SSN). The
comparison of MSC with the whole set of SSN reveals rather close correspondence
of cycle timings, duration and maxima times for the cycles 12- 24, 6,7 and
-4,-3. Although, in 1720-1760 and 1830-1860 there are discrepancies in maximum
amplitudes of the cycles, durations and shifts of the maximum times between MSC
and SSN curves. The MSC curve reveals pretty regular cycles with double maxima
(cycles 1-4), triple maximum amplitude distributions for cycles 0 and 1 and for
cycles -1 and -2 just before Maunder minimum. The MSC cycles in 1700-1750
reveal smaller maximal magnitudes in cycles -3 to 0 and in cycle 1-4 than the
amplitudes of SSN, while cycles -2 to 0 have reversed maxima with minima with
SSN. Close fitting of MSC or Bayesian models to the sunspot curve distorts the
occurrences of either Maunder Minimum or/and modern grand solar minimum
(2020-2053). These discrepancies can be caused by poor observations and by
difference in solar magnetic fields responsible for these proxies. The dynamo
simulations of toroidal and poloidal magnetic field in the grand solar cycle
(GSC) from 1650 until 2050 demonstrate the clear differences between their
amplitude variations during the GSC. The use of eigen vectors of SBMF can
provide additional information to that derived from SSN that can be useful for
understanding solar activity.Comment: 23 pages, 9 figur
Effect of considering the initial parameters on accuracy of experimental studies conclusions
The presented paper contains the evidences of the necessity to take into account the initial level of physiological parameters while conducting the biomedical research; it is exemplified by certain indicators of cardiorespiratory system. The analysis is based on the employment of data obtained via the multiple surveys of medical and pharmaceutical college students. There has been revealed a negative correlation of changes of the studied parameters of cardiorespiratory system in the repeated measurements compared to their initial level. It is assumed that the dependence of the changes of physiological parameters from the baseline can be caused by the biorhythmic changes inherent for all body systems
Inversionless light amplification and optical switching controlled by state-dependent alignment of molecules
We propose a method to achieve amplification without population inversion by
anisotropic molecules whose orientation by an external electric field is
state-dependent. It is based on decoupling of the lower-state molecules from
the resonant light while the excited ones remain emitting. The suitable class
of molecules is discussed, the equation for the gain factor is derived, and the
magnitude of the inversionless amplification is estimated for the typical
experimental conditions. Such switching of the sample from absorbing to
amplifying via transparent state is shown to be possible both with the aid of
dc and ac control electric fields.Comment: AMS-LaTeX v1.2, 4 pages with 4 figure
Experiment K-6-16. Morphological examination of rat testes. The effect of Cosmos 1887 flight on spermatogonial population and testosterone level in rat testes
Testes from rats flown on Cosmos 1887 for twelve and a half days were compared to basal control, synchronous control and vivarium maintained rats. When the mean weights of flight testes, normalized for weight/100 gms, were compared to the vivarium controls they were 6.7 percent lighter. Although the flight testes were lighter than the synchronous, the difference is not significant. Counts of spermatogonial cells from 5 animals in each group revealed a 4 percent decrease in flight compared to vivarium controls. In both cases the t-Test significance was less than 0.02. The serum testosterone levels of all animals (flight, synchronous and vivarium) were significantly below the basal controls
The SNF1-type serine-threonine protein kinase SAPK4 regulates stress-responsive gene expression in rice
Diedhiou CJ, Popova OV, Dietz K-J, Golldack D. The SNF1-type serine-threonine protein kinase SAPK4 regulates stress-responsive gene expression in rice. BMC PLANT BIOLOGY. 2008;8(1):49.BACKGROUND: Plants respond to extracellularly perceived abiotic stresses such as low temperature, drought, and salinity by activation of complex intracellular signaling cascades that regulate acclimatory biochemical and physiological changes. Protein kinases are major signal transduction factors that have a central role in mediating acclimation to environmental changes in eukaryotic organisms. In this study, we characterized the function of the sucrose nonfermenting 1-related protein kinase2 (SnRK2) SAPK4 in the salt stress response of rice. RESULTS: Translational fusion of SAPK4 with the green fluorescent protein (GFP) showed subcellular localization in cytoplasm and nucleus. To examine the role of SAPK4 in salt tolerance we generated transgenic rice plants with over-expression of rice SAPK4 under control of the CaMV-35S promoter. Induced expression of SAPK4 resulted in improved germination, growth and development under salt stress both in seedlings and mature plants. In response to salt stress, the SAPK4-overexpressing rice accumulated less Na+ and Cl- and showed improved photosynthesis. SAPK4-regulated genes with functions in ion homeostasis and oxidative stress response were identified: the vacuolar H+-ATPase, the Na+/H+ antiporter NHX1, the Cl- channel OsCLC1 and a catalase. CONCLUSION: Our results show that SAPK4 regulates ion homeostasis and growth and development under salinity and suggest function of SAPK4 as a regulatory factor in plant salt stress acclimation. Identification of signaling elements involved in stress adaptation in plants presents a powerful approach to identify transcriptional activators of adaptive mechanisms to environmental changes that have the potential to improve tolerance in crop plants
Galactic Rotation Parameters from Data on Open Star Clusters
Currently available data on the field of velocities Vr, Vl, Vb for open star
clusters are used to perform a kinematic analysis of various samples that
differ by heliocentric distance, age, and membership in individual structures
(the Orion, Carina--Sagittarius, and Perseus arms). Based on 375 clusters
located within 5 kpc of the Sun with ages up to 1 Gyr, we have determined the
Galactic rotation parameters
Wo =-26.0+-0.3 km/s/kpc,
W'o = 4.18+-0.17 km/s/kpc^2,
W''o=-0.45+-0.06 km/s/kpc^3, the system contraction parameter K = -2.4+-0.1
km/s/kpc, and the parameters of the kinematic center Ro =7.4+-0.3 kpc and lo =
0+-1 degrees. The Galactocentric distance Ro in the model used has been found
to depend significantly on the sample age. Thus, for example, it is 9.5+-0.7
kpc and 5.6+-0.3 kpc for the samples of young (50 Myr)
clusters, respectively. Our study of the kinematics of young open star clusters
in various spiral arms has shown that the kinematic parameters are similar to
the parameters obtained from the entire sample for the Carina-Sagittarius and
Perseus arms and differ significantly from them for the Orion arm. The
contraction effect is shown to be typical of star clusters with various ages.
It is most pronounced for clusters with a mean age of 100 Myr, with the
contraction velocity being Kr = -4.3+-1.0 km/s.Comment: 14 pages, 4 figures, 2 table
The image of mother in the drama of Tennessee Willams
The article is devoted to the review of those means of artistic expression by which T. Williams creates the image of mother in his early plays, the psychology of the image, as well as options for its transformation in subsequent plays. We pay attention to two characters of his early plays - Amanda Wingfield (The Glass Menagerie) and Serafina della Rosa (The Rose Tattoo).Статья посвящена рассмотрению тех средств художественной выразительности, с помощью которых Т. Уильямс создает образ матери в своих ранних произведениях, психологии образа, а также вариантов его трансформации в последующих пьесах. Внимание уделяется двум героиням его ранних пьес - Аманде Уингфилд ("Стеклянный зверинец") и Серафине делла Розе ("Татуированная роза")
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