3,488 research outputs found
Proposal of a spin torque majority gate logic
A new spin based logic device is proposed. It is comprised of a common free
ferromagnetic layer separated by a tunnel junction from three inputs and one
output with separate fixed layers. It has the functionality of a majority gate
and is switched by spin transfer torque. Validity of its logic operation is
demonstrated by micromagnetic simulation. A version of such devices with
perpendicular magnetization is examined. Switching encompasses moving domain
walls. The device reuses most of the materials and structures from spin torque
RAM, and is entirely compatible with CMOS technology.Comment: 14 pages, 4 figure
Multi-parameter approach to R-parity violating SUSY couplings
We introduce and implement a new, extended approach to placing bounds on
trilinear R-parity violating couplings. We focus on a limited set of leptonic
and semi-leptonic processes involving neutrinos, combining multidimensional
plotting and cross-checking constraints from different experiments. This allows
us to explore new regions of parameter space and to relax a number of bounds
given in the literature. We look for qualitatively different results compared
to those obtained previously using the assumption that a single coupling
dominates the R-parity violating contributions to a process (SCD). By combining
results from several experiments, we identify regions in parameter space where
two or more parameters approach their maximally allowed values. In the same
vein, we show a circumstance where consistency between independent bounds on
the same combinations of trilinear coupling parameters implies mass constraints
among slepton or squark masses. Though our new bounds are in most cases weaker
than the SCD bounds, the largest deviations we find on individual parameters
are factors of two, thus indicating that a conservative, order of magnitude
bound on an individual coupling is reliably estimated by making the SCD
assumption.Comment: 30 pages, 8 figures, 2 tables. Typos fixed, two references added and
references updated. Eq. (41) removed, Eq. (40) and text modified. Published
versio
Health care for older adults in Europe: how has it evolved and what are the challenges?
Geriatric medicine has evolved to an accepted specialty in 23 European countries. Despite much heterogeneity of postgraduate geriatric curricula, European societies have succeeded in defining a common core curriculum with a list of minimum training requirements for obtaining the specialty title of geriatric medicine. Geriatricians play a leading role in finding solutions for the challenges of health care of multimorbid older patients. One of these challenges is the demographic shift with the number of adults aged 80 years and older in Europe expected to double by 2050. Although geriatric units will play a role in the care of frail older patients, new care models are needed to integrate the comprehensive geriatric assessment approach for the care of the vast majority of older patients admitted to non-geriatric hospital units. Over the last few years, co-management approaches have been developed to address this gap. Innovative models are also in progress for ambulatory care, prevention and health promotion programs, and long-term care. Efforts to implement geriatric learning objectives in undergraduate training, and the generation of practice guidelines for geriatric syndromes may help to improve the quality of care for older patients
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