3,140 research outputs found
The effect of cardiac resynchronization on morbidity and mortality in heart failure
Background:
Cardiac resynchronization reduces symptoms and improves left ventricular function in
many patients with heart failure due to left ventricular systolic dysfunction and cardiac
dyssynchrony. We evaluated its effects on morbidity and mortality.
Methods:
Patients with New York Heart Association class III or IV heart failure due to left ventricular
systolic dysfunction and cardiac dyssynchrony who were receiving standard pharmacologic
therapy were randomly assigned to receive medical therapy alone or with cardiac
resynchronization. The primary end point was the time to death from any cause or an
unplanned hospitalization for a major cardiovascular event. The principal secondary end
point was death from any cause.
Results:
A total of 813 patients were enrolled and followed for a mean of 29.4 months. The primary
end point was reached by 159 patients in the cardiac-resynchronization group, as
compared with 224 patients in the medical-therapy group (39 percent vs. 55 percent;
hazard ratio, 0.63; 95 percent confidence interval, 0.51 to 0.77; P<0.001). There were
82 deaths in the cardiac-resynchronization group, as compared with 120 in the medical-therapy
group (20 percent vs. 30 percent; hazard ratio 0.64; 95 percent confidence
interval, 0.48 to 0.85; P<0.002). As compared with medical therapy, cardiac resynchronization
reduced the interventricular mechanical delay, the end-systolic volume index,
and the area of the mitral regurgitant jet; increased the left ventricular ejection fraction;
and improved symptoms and the quality of life (P<0.01 for all comparisons).
Conclusions:
In patients with heart failure and cardiac dyssynchrony, cardiac resynchronization improves
symptoms and the quality of life and reduces complications and the risk of death.
These benefits are in addition to those afforded by standard pharmacologic therapy.
The implantation of a cardiac-resynchronization device should routinely be considered
in such patients
Von Referenz-Prominenz und Rezeptions-Differenz. Immanuel Kant in (quasi-)erziehungswissenschaftlichen LehrbĂŒchern
Der Autor untersucht die heterogene Rezeption Immanuel Kants und nutzt dazu wissenschaftlich-pĂ€dagogische bzw. erziehungswissenschaftliche LehrbĂŒcher. Mittels Referenzanalyse in den ZeitrĂ€umen 1750-1850 und 1983-2017 zeigt er, wie facettenreich die Verwendungsweisen in den erziehungswissenschaftlichen Themenkomplexen sind und dass sich dennoch eine spezifische Dominanz von Themen in Philosophie, (pĂ€dagogischer) Theoriebildung und Anthropologie herausstellen lĂ€sst, die sich ĂŒber die Zeit verschiebt. (DIPF/Orig.
Ghosts in modular representation theory
A ghost over a finite p-group G is a map between modular representations of G
which is invisible in Tate cohomology. Motivated by the failure of the
generating hypothesis---the statement that ghosts between finite-dimensional
G-representations factor through a projective---we define the ghost number of
kG to be the smallest integer l such that the composition of any l ghosts
between finite-dimensional G-representations factors through a projective. In
this paper we study ghosts and the ghost numbers of p-groups. We begin by
showing that a weaker version of the generating hypothesis, where the target of
the ghost is fixed to be the trivial representation k, holds for all p-groups.
We then compute the ghost numbers of all cyclic p-groups and all abelian
2-groups with C_2 as a summand. We obtain bounds on the ghost numbers for
abelian p-groups and for all 2-groups which have a cyclic subgroup of index 2.
Using these bounds we determine the finite abelian groups which have ghost
number at most 2. Our methods involve techniques from group theory,
representation theory, triangulated category theory, and constructions
motivated from homotopy theory.Comment: 15 pages, final version, to appear in Advances in Mathematics. v4
only makes changes to arxiv meta-data, correcting the abstract and adding a
do
Host habitat assessment by a parasitoid using fungal volatiles
BACKGROUND: The preference â performance hypothesis predicts that oviposition preference of insects should correlate with host suitability for offspring development. Therefore, insect females have to be able to assess not only the quality of a given host but also the environmental conditions of the respective host habitat. Chemical cues are a major source of information used by insects for this purpose. Primary infestation of stored grain by stored product pests often favors the intense growth of mold. This can lead to distinct sites of extreme environmental conditions (hot-spots) with increased insect mortality. We studied the influence of mold on chemical orientation, host recognition, and fitness of Lariophagus distinguendus, a parasitoid of beetle larvae developing in stored grain. RESULTS: Volatiles of wheat infested by Aspergillus sydowii and A. versicolor repelled female parasitoids in an olfactometer. Foraging L. distinguendus females are known to be strongly attracted to the odor of larval host feces from the granary weevil Sitophilus granarius, which may adhere in remarkable amounts to the surface of the grains. Feces from moldy weevil cultures elicited neutral responses but parasitoids clearly avoided moldy feces when non-moldy feces were offered simultaneously. The common fungal volatile 1-octen-3-ol was the major component of the odor of larval feces from moldy weevil cultures and repelled female parasitoids at naturally occurring doses. In bioassays investigating host recognition behavior of L. distinguendus, females spent less time on grains containing hosts from moldy weevil cultures and showed less drumming and drilling behavior than on non-moldy controls. L. distinguendus had a clearly reduced fitness on hosts from moldy weevil cultures. CONCLUSION: We conclude that L. distinguendus females use 1-octen-3-ol for host habitat assessment to avoid negative fitness consequences due to secondary mold infestation of host patches. The female response to fungal volatiles is innate, suggesting that host-associated fungi played a crucial role in the evolution of host finding strategies of L. distinguendus. Research on the role of host-associated microorganisms in the chemically mediated orientation of parasitoids is still at the beginning. We expect an increasing recognition of this issue in the future
Cosmic ray propagation with CRPropa 3
Solving the question of the origin of ultra-high energy cosmic rays (UHECRs)
requires the development of detailed simulation tools in order to interpret the
experimental data and draw conclusions on the UHECR universe. CRPropa is a
public Monte Carlo code for the galactic and extragalactic propagation of
cosmic ray nuclei above eV, as well as their photon and neutrino
secondaries. In this contribution the new algorithms and features of CRPropa 3,
the next major release, are presented. CRPropa 3 introduces time-dependent
scenarios to include cosmic evolution in the presence of cosmic ray deflections
in magnetic fields. The usage of high resolution magnetic fields is facilitated
by shared memory parallelism, modulated fields and fields with heterogeneous
resolution. Galactic propagation is enabled through the implementation of
galactic magnetic field models, as well as an efficient forward propagation
technique through transformation matrices. To make use of the large Python
ecosystem in astrophysics CRPropa 3 can be steered and extended in Python.Comment: 16th International workshop on Advanced Computing and Analysis
Techniques in physics research (ACAT 2014) proceedings, 6 pages, 6 figure
CRPropa 3.0 - a Public Framework for Propagating UHE Cosmic Rays through Galactic and Extragalactic Space
The interpretation of experimental data of ultra-high energy cosmic rays
(UHECRs) above 10^17 eV is still under controversial debate. The development
and improvement of numerical tools to propagate UHECRs in galactic and
extragalactic space is a crucial ingredient to interpret data and to draw
conclusions on astrophysical parameters. In this contribution the next major
release of the publicly available code CRPropa (3.0) is presented. It reflects
a complete redesign of the code structure to facilitate high performance
computing and comprises new physical features such as an interface for galactic
propagation using lensing techniques and inclusion of cosmological effects in a
three-dimensional environment. The performance is benchmarked and first
applications are presented.Comment: 4 pages, 3 figures. Proceedings of the 33rd International Cosmic Ray
Conference (ICRC), Rio de Janeiro, Brazil, 2-9 July 201
Erziehungswissenschaftliche Wissensgeschichte aus der Distanz, oder: Die Vermessung erziehungswissenschaftlichen "Grundwissens" durch Methoden aus dem Bereich des "distant reading". Ein Werkstattbericht
Der Beitrag thematisiert digitale Verfahren zur historischen Wissens- und Wissenschaftsforschung in der Erziehungswissenschaft. Die Autor*innen befassen sich dafĂŒr insbesondere mit computergestĂŒtzten Anwendungen des Topic Modeling, einem gĂ€ngigen Verfahren zur automatisierten Inhaltsanalyse. Durch die Möglichkeit des distant reading, so die These des Beitrags, könne neues erziehungswissenschaftliches Wissen auch aus bereits bekannten Quellen und Datenkorpora gewonnen bzw. âneu vermessenâ werden. (DIPF/Orig.
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