2,848,480 research outputs found
Centers and homotopy centers in enriched monoidal categories
We consider a theory of centers and homotopy centers of monoids in monoidal
categories which themselves are enriched in duoidal categories. Duoidal
categories (introduced by Aguillar and Mahajan under the name 2-monoidal
categories) are categories with two monoidal structures which are related by
some, not necessary invertible, coherence morphisms. Centers of monoids in this
sense include many examples which are not `classical.' In particular, the
2-category of categories is an example of a center in our sense. Examples of
homotopy center (analogue of the classical Hochschild complex) include the
Gray-category Gray of 2-categories, 2-functors and pseudonatural
transformations and Tamarkin's homotopy 2-category of dg-categories,
dg-functors and coherent dg-transformations.Comment: 52 page
Conversion of neutral nitrogen-vacancy centers to negatively-charged nitrogen-vacancy centers through selective oxidation
The conversion of neutral nitrogen-vacancy centers to negatively charged
nitrogen-vacancy centers is demonstrated for centers created by ion
implantation and annealing in high-purity diamond. Conversion occurs with
surface exposure to an oxygen atmosphere at 465 C. The spectral properties of
the charge-converted centers are investigated. Charge state control of
nitrogen-vacancy centers close to the diamond surface is an important step
toward the integration of these centers into devices for quantum information
and magnetic sensing applications.Comment: 4 pages, 3 figure
Non-Euclidean Triangle Centers
Non-Euclidean triangle centers can be described using homogeneous coordinates
that are proportional to the generalized sines of the directed distances of a
given center from the edges of the reference triangle. Identical homogeneous
coordinates of a specific triangle center may be used for all spaces of uniform
Gaussian curvature. We also define the median point for a set of points in
non-Euclidean space and a planar center of rotation for a set of points in a
non-Euclidean plane.Comment: 29 pages, 12 figures; added calculations of planar center of rotation
for edges and interior of an isosceles triangl
Variability of extracorporeal cardiopulmonary resuscitation utilization for refractory adult out-of-hospital cardiac arrest: an international survey study.
Objective: A growing interest in extracorporeal cardiopulmonary resuscitation (ECPR) as a rescue strategy for refractory adult out-of-hospital cardiac arrest (OHCA) currently exists. This study aims to determine current standards of care and practice variation for ECPR patients in the USA and Korea.
Methods: In December 2015, we surveyed centers from the Korean Hypothermia Network (KORHN) Investigators and the US National Post-Arrest Research Consortium (NPARC) on current targeted temperature management and ECPR practices. This project analyzes the subsection of questions addressing ECPR practices. We summarized survey.
Results: Overall, 9 KORHN and 4 NPARC centers reported having ECPR programs and had complete survey data available. Two KORHN centers utilized extracorporeal membrane oxygenation only for postarrest circulatory support in patients with refractory shock and were excluded from further analysis. Centers with available ECPR generally saw a high volume of OHCA patients (10/11 centers care for \u3e75 OHCA a year). Location of, and providers trained for cannulation varied across centers. All centers in both countries (KORHN 7/7, NPARC 4/4) treated comatose ECPR patients with targeted temperature management. All NPARC centers and four of seven KORHN centers reported having a standardized hospital protocol for ECPR. Upper age cutoff for eligibility ranged from 60 to 75 years. No absolute contraindications were unanimous among centers.
Conclusion: A wide variability in practice patterns exist between centers performing ECPR for refractory OHCA in the US and Korea. Standardized protocols and shared research databases might inform best practices, improve outcomes, and provide a foundation for prospective studies
Israel in Jewish Community Centers
An exploration of Jewish Community Centers, their historical significance, and the pivotal role they continue to play in engaging the community in meaningful and substantive "up-to-date" Israel experiences
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