212,581 research outputs found
Higgs Phenomenology of Minimal Universal Extra Dimensions
The minimal model of Universal Extra Dimensions (MUED) is briefly reviewed.
We explain how the cross-sections for Higgs production via gluon fusion and
decay into two photons are modified, relative the the Standard Model (SM)
values, by KK particles running in loops, leading to an enhancement of the gg
to h to two photons and gg to h to W+W- cross-sections. ATLAS and CMS searches
for the SM Higgs in these channels are reinterpreted in the context of MUED and
used to place new limits on the MUED parameter space. Only a small region of
between 1 and 3 GeV around mh = 125 GeV for 500 GeV < 1/R < 1600 GeV remains
open at the 95 % confidence level.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011),
Paris, France, November 14-18 2011, 3 pages, 4 figure
Force platform recordings in the diagnosis of primary orthostatic tremor
Primary orthostatic tremor (OT) consists of rhythmical muscle contractions at a frequency of around 16 Hz, causing discomfort and/or unsteadiness while standing. Diagnosis has hitherto relied on recording Electromyography (EMG) from affected muscles. The main aim of this study was to see if the characteristic postural tremor in OT can be identified with force platforms. We also quantified postural sway in OT patients to assess their degree of objective unsteadiness. Finally, we investigated the time relations between bursts of activity in the various affected muscle groups. Subjects stood on a force platform with concurrent multichannel surface EMG recordings from the lower limbs. Seven patients with clinical and EMG diagnosis of OT were examined and the force platform data compared with those of 21 other neurological patients with postural tremor and eight normal controls. All OT patients had high frequency peaks in power spectra of posturography and EMG recordings (12–16 Hz). No such high frequency activity was evident in patients with Parkinson's disease, cerebellar degenerations, essential tremor or in healthy controls. Additionally, OT patients showed increased sway at low frequencies relative to normal controls, suggesting that the unsteadiness reported by OT patients is at least partly due to increased postural sway. Examination of EMG timing showed fixed patterns of muscle activation when maintaining a quiet stance within but not across OT patients. These data show a high correlation between EMG and posturography and confirm that OT may be diagnosed using short epochs of force platform recordings
The Cohen Macaulay property for noncommutative rings
Let R be a noetherian ring which is a finite module over its centre Z(R).
This paper studies the consequences for R of the hypothesis that it is a
maximal Cohen Macaulay Z(R)-module. Old results are reviewed and a number of
new results are proved. The additional hypothesis of homological grade symmetry
is proposed as the appropriate extra lever needed to extend the classical
commutative homological hierarchy to this setting, and results are given
offering evidence in support of this proposal.Comment: Preliminary version; comments welcom
Service Learning in Undergraduate Nursing Education: Strategies to Facilitate Meaningful Reflection
Service learning is recognized as a valuable pedagogy involving experiential learning, reflection, and reciprocal learning. Students develop critical thinking and social awareness by using the crucial activity of reflecting upon their experiential learning with community partners. The purpose of this paper is to demystify the process of reflection by identifying best practices to enhance reflection and offering suggestions for grading. By understanding “the what” and “the how” of reflection, educators can implement service learning experiences designed to include the essential component of reflection. Strategies for facilitating meaningful reflection are described including descriptions of what students should reflect upon and how to initiate reflection through writing, reading, doing, and telling. Grading rubrics are suggested to facilitate evaluation of student reflection. When properly implemented, service learning encourages students to be good citizens of the world. By using best practices associated with reflection, students can be challenged to think critically about the world and how their service can achieve community goals
Nuclear Structure Aspects of Neutrinoless Double Beta Decay
We decompose the neutrinoless double-beta decay matrix elements into sums of
products over the intermediate nucleus with two less nucleons. We find that the
sum is dominated by the J^pi=0^+ ground state of this intermediate nucleus for
both the light and heavy neutrino decay processes. This provides a new
theoretical tool for comparing and improving nuclear structure models. It also
provides the connection to two-nucleon transfer experiments.Comment: 5 pages, 6 figure
- …