1,161 research outputs found
Spectral Decomposition of Missing Transverse Energy at Hadron Colliders
We propose a spectral decomposition to systematically extract information of
dark matter at hadron colliders. The differential cross section of events with
missing transverse energy (MET) can be expressed by a linear combination of
basis functions. In the case of -channel mediator models for dark matter
particle production, basis functions are identified with the differential cross
sections of sub-processes of virtual mediator and visible particle production
while the coefficients of basis functions correspond to dark matter invariant
mass distribution in the manner of the K\"all\'en-Lehmann spectral
decomposition. For a given MET data set and mediator model, we show that one
can differentiate a certain dark matter-mediator interaction from another
through spectral decomposition.Comment: 6+4 pages, 6 figures, PRL versio
125 GeV Higgs as a pseudo-Goldstone boson in supersymmetry with vector-like matters
We propose a possibility of the 125 GeV Higgs being a pseudo-Goldstone boson
in supersymmetry with extra vector-like fermions. Higgs mass is obtained from
loops of top quark and vector-like fermions from the global symmetry breaking
scale f at around TeV. The mu, Bmu/mu \sim f are generated from the dynamics of
global symmetry breaking and the Higgs quartic coupling vanishes at f as tan
beta \simeq 1. The relation of msoft \sim with f \sim mu \sim m_soft
\sim TeV is obtained and large mu does not cause a fine tuning for the
electroweak symmetry breaking. The Higgs to di-photon rate can be enhanced from
the loop of uncolored vector-like matters. The stability problem of Higgs
potential with vector-like fermions can be nicely cured by the UV completion
with the Goldstone picture.Comment: 28 pages, 8 figure
Transmission Electron Microscopy (TEM) Sample Preparation of Si(1-x)Gex in c-Plane Sapphire Substrate
The National Aeronautics and Space Administration-invented X-ray diffraction (XRD) methods, including the total defect density measurement method and the spatial wafer mapping method, have confirmed super hetero epitaxy growth for rhombohedral single crystalline silicon germanium (Si1-xGex) on a c-plane sapphire substrate. However, the XRD method cannot observe the surface morphology or roughness because of the method s limited resolution. Therefore the authors used transmission electron microscopy (TEM) with samples prepared in two ways, the focused ion beam (FIB) method and the tripod method to study the structure between Si1-xGex and sapphire substrate and Si1?xGex itself. The sample preparation for TEM should be as fast as possible so that the sample should contain few or no artifacts induced by the preparation. The standard sample preparation method of mechanical polishing often requires a relatively long ion milling time (several hours), which increases the probability of inducing defects into the sample. The TEM sampling of the Si1-xGex on sapphire is also difficult because of the sapphire s high hardness and mechanical instability. The FIB method and the tripod method eliminate both problems when performing a cross-section TEM sampling of Si1-xGex on c-plane sapphire, which shows the surface morphology, the interface between film and substrate, and the crystal structure of the film. This paper explains the FIB sampling method and the tripod sampling method, and why sampling Si1-xGex, on a sapphire substrate with TEM, is necessary
Role of Transcription Factor Modifications in the Pathogenesis of Insulin Resistance
Non-alcoholic fatty liver disease (NAFLD) is characterized by fat accumulation in the liver not due to alcohol abuse. NAFLD is accompanied by variety of symptoms related to metabolic syndrome. Although the metabolic link between NAFLD and insulin resistance is not fully understood, it is clear that NAFLD is one of the main cause of insulin resistance. NAFLD is shown to affect the functions of other organs, including pancreas, adipose tissue, muscle and inflammatory systems. Currently efforts are being made to understand molecular mechanism of interrelationship between NAFLD and insulin resistance at the transcriptional level with specific focus on post-translational modification (PTM) of transcription factors. PTM of transcription factors plays a key role in controlling numerous biological events, including cellular energy metabolism, cell-cycle progression, and organ development. Cell type- and tissue-specific reversible modifications include lysine acetylation, methylation, ubiquitination, and SUMOylation. Moreover, phosphorylation and O-GlcNAcylation on serine and threonine residues have been shown to affect protein stability, subcellular distribution, DNA-binding affinity, and transcriptional activity. PTMs of transcription factors involved in insulin-sensitive tissues confer specific adaptive mechanisms in response to internal or external stimuli. Our understanding of the interplay between these modifications and their effects on transcriptional regulation is growing. Here, we summarize the diverse roles of PTMs in insulin-sensitive tissues and their involvement in the pathogenesis of insulin resistance
Fine-Tuning the Retrieval Mechanism for Tabular Deep Learning
While interests in tabular deep learning has significantly grown,
conventional tree-based models still outperform deep learning methods. To
narrow this performance gap, we explore the innovative retrieval mechanism, a
methodology that allows neural networks to refer to other data points while
making predictions. Our experiments reveal that retrieval-based training,
especially when fine-tuning the pretrained TabPFN model, notably surpasses
existing methods. Moreover, the extensive pretraining plays a crucial role to
enhance the performance of the model. These insights imply that blending the
retrieval mechanism with pretraining and transfer learning schemes offers
considerable potential for advancing the field of tabular deep learning.Comment: Table Representation Learning Workshop at NeurIPS 202
Effects of sufficient anticoagulation on ischemic stroke outcomes in patients with nonvalvular atrial fibrillation
Background Optimal anticoagulation therapy reduces the risk of ischemic stroke in patients with nonvalvular atrial fibrillation (AF). Therefore, we aimed to evaluate the effects of prior anticoagulation therapy with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) on ischemic stroke outcomes in patients with nonvalvular AF. Methods We enrolled 487 patients with ischemic stroke and nonvalvular AF between January 2013 and August 2020. The infarct volume was semi-automatically evaluated using diffusion-weighted magnetic resonance imaging. Patients were categorized into no anticoagulation, undertreated anticoagulation, and sufficient anticoagulation (with VKA or DOAC) groups based on their pre-admission anticoagulant use, and the clinical characteristics were compared between the groups. Results Among the included patients, 374 (76.8%), 50 (10.3%), 10 (2.1%), and 53 (10.9%) patients received no anticoagulants, were undertreated with a VKA, were sufficiently treated with a VKA, and received DOACs, respectively, before stroke. Multivariate analysis revealed that optimal anticoagulation was independently associated with a low risk of severe stroke (odds ratio, 0.553; 95% confidence interval, 0.308–0.992; P=0.047). Additionally, the DOAC group had a significantly smaller mean infarct volume than the other groups (45.8±73.2, 45.0±69.1, 30.9±24.7, and 12.6±24.9 mL in the no anticoagulation, insufficient VKA, sufficient VKA, and DOAC groups, respectively; P=0.011). Conclusion Sufficient pre-stroke anticoagulation is associated with mild stroke severity and good outcomes at 3 months post-stroke. Additionally, pre-stroke DOAC treatment is associated with smaller infarct volume in patients with ischemic stroke and nonvalvular AF
Diurnal variation in quantitative pupillary reactivity in large hemispheric stroke
Background Pupillary light reflex (PLR) assessment is an important neurological examination reflecting neurological deterioration in severe stroke cases. This study investigated the impact of diurnal variation in the PLR using quantitative pupillometry in stable patients with large hemispheric stroke. Methods We included 35 patients with large hemispheric stroke without neurological worsening, who were admitted to the neurological intensive care unit between April 2017 and November 2021. Quantitative pupillometry was performed every 4 hours. Pupillometer parameters of maximum pupil size, percentage of constriction (%CH), latency (LAT), constriction velocity (CV), dilation velocity (DV), maximum constriction velocity (MCV), and neurological pupil index (NPi) score were recorded. We evaluated changes in the pupillometer parameters over time using linear mixed model analysis. Results The diurnal variations revealed that the following parameters were significantly higher at 04:00 than at 20:00: maximum pupil size (right [Rt]: 3.59 vs. 3.21 mm, P<0.001; left [Lt]: 3.51 vs. 3.18 mm, P<0.001), %CH (Rt: 31.48 vs. 25.72, P<0.001; Lt: 31.42 vs. 24.98, P<0.001), CV (Rt: 1.97 vs. 1.68 mm/sec, P<0.001; Lt: 1.98 vs. 1.65 mm/sec, P<0.001), and DV (Rt: 0.97 vs. 0.84 mm/sec, P<0.001; Lt: 0.94 vs. 0.82 mm/sec, P=0.001). However, no significant diurnal variations were observed in the NPi values. Conclusion Pupillary dynamics based on quantitative pupillometer parameters, including the NPi, demonstrated diurnal variations over 24 hours in large hemispheric stroke patients without neurological worsening. However, all changes in the pupillometer parameters were within normal ranges
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