3,824 research outputs found
Pressure and convective heat-transfer measure- ments in a shock tunnel using several test gases
Pressure and convective heat-transfer measurements on hemisphere-cylinder, blunted 30 degree cone, in shock tunnel using several test gase
Magnetospheric particle acceleration and X-ray emission of pulsars
The available data on isolated X-ray pulsars, their wind nebulae, and the
supernova remnants which are connected to some of these sources are analyzed.
It is shown that electric fields of neutron stars tear off charged particles
from the surface of neutron star and trigger the acceleration of particles. The
charged particles are accelerated mainly in the field of magneto-dipole
radiation wave. Power and energy spectra of the charged particles depend on the
strength of the magneto-dipole radiation. Therefore, the X-ray radiation is
strongly dependent on the rate of rotational energy loss and weakly dependent
on the electric field intensity. Coulomb interaction between the charged
particles is the main factor for the energy loss and the X-ray spectra of the
charged particles.Comment: minor correction on table format, 20 pages (4 figures, 1 table),
submitted to International Journal of Modern Physics
Effects of Saccharomyces boulardii on antibiotic induced orocecal transit in rats
Clarithromycin is an antibiotic widely used for Helicobacter pylori (H. pylori) eradication and together with amoxicillin and proton pump inhibitors they constitute the first line triple treatment regimen against H. pylori. Diarrhoea is one of the major drawbacks during H. pylori eradication and is majorly attributed to clarithromycin, while Saccharomyces boulardii is a probiotic and is shown to be effective in the treatment of antibiotic associated diarrhoea. We aimed to evaluate the effect of clarithromycin on orocecal transit in rats and to identify whether the supplementation with S. boulardii has a role on orocecal transit index. Adult rats of both sexes were divided into two groups to determine immediate or chronic effects of S. boulardii and clarithromycin on orocecal transit. The first group was given single dose of the test drug, while the second group received the test drugs for one week through orogastric intubation. Both groups were randomly distributed into four subgroups; the placebo group (group A), the S. boulardii group (group B), the clarithromycin group (group C), and the co-administration that is clarithromycin plus S. boulardii group (group D). Rats were given 20 mg kg−1 clarithromycin and 500 mg kg−1S. boulardii. We did not find any difference among the subgroups in group 1, where only single dose of the test drugs was administered. In chronic administration group, that is group 2, significant differences among the subgroups were observed (P=0.004). Post-hoc comparisons of orocecal transit index between group “2A and 2C” and “2C and 2D” were significantly different (P=0.013 and P=0.005, respectively). Our results show that long term clarithromycin administration leads to rapid orocecal transit index and S. boulardii supplementation to clarithromycin can abolish this adverse effect in rats. Those findings suggest the beneficial use of S. boulardii in H. pylori eradication regimens
Products, coproducts and singular value decomposition
Products and coproducts may be recognized as morphisms in a monoidal tensor
category of vector spaces. To gain invariant data of these morphisms, we can
use singular value decomposition which attaches singular values, ie generalized
eigenvalues, to these maps. We show, for the case of Grassmann and Clifford
products, that twist maps significantly alter these data reducing degeneracies.
Since non group like coproducts give rise to non classical behavior of the
algebra of functions, ie make them noncommutative, we hope to be able to learn
more about such geometries. Remarkably the coproduct for positive singular
values of eigenvectors in yields directly corresponding eigenvectors in
A\otimes A.Comment: 17 pages, three eps-figure
Real extensions of distal minimal flows and continuous topological ergodic decompositions
We prove a structure theorem for topologically recurrent real skew product
extensions of distal minimal compact metric flows with a compactly generated
Abelian acting group (e.g. -flows and -flows). The main result
states that every such extension apart from a coboundary can be represented by
a perturbation of a so-called Rokhlin skew product. We obtain as a corollary
that the topological ergodic decomposition of the skew product extension into
prolongations is continuous and compact with respect to the Fell topology on
the hyperspace. The right translation acts minimally on this decomposition,
therefore providing a minimal compact metric analogue to the Mackey action.
This topological Mackey action is a distal (possibly trivial) extension of a
weakly mixing factor (possibly trivial), and it is distal if and only if
perturbation of the Rokhlin skew product is defined by a topological
coboundary.Comment: This paper is an extension and generalisation of
http://arxiv.org/abs/0909.0192. The result has been generalised from actions
of the group of integers to actions of Abelian compactly generated
transformation groups. Therefore the title had to be changed (homeomorphisms
vs. flows
Students’ Perspectives on a Gap-Funded Program: The Community Scholarship Program of McCracken County, Kentucky
In 2010, McCracken County, Kentucky implemented the Community Scholarship Program (CSP) to provide graduates of high schools in the county an opportunity to receive a tuition-free community college education. Quantitative data was collected throughout the various stages of student progress through the program. As the first cohort of CSP students approached graduation from West Kentucky Community and Technical College (WKCTC) in Spring 2016, we initiated a qualitative study. We interviewed 19 of the 88 continuously enrolled students from the first CSP cohort in a series of three focus groups in February and March of 2016. Those group interviews focused on addressing the impact of CSP, from a student perspective, on enrollment, persistence, and completion of a credential at WKCTC. Key issues that emerged include the importance students place on (a) having every high school senior complete the FAFSA® and a WKCTC first-semester schedule; (b) building relationships with college personnel, especially success coaches, who provide both academic and personal advice and encouragement; (c) providing a clearer explanation of what a gap-funded scholarship program covers; and (d) restructuring the program to cover more college-going expenses. This paper presents several implications for practice
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