3,953 research outputs found
Adiabatic Electroweak Baryogenesis Driven by an Axion-like Particle
An axion-like particle (ALP) offers a new direction in electroweak
baryogenesis because the periodic nature enables it to trigger a strong
first-order phase transition insensitively to the decay constant . For
much above TeV, the ALP-induced electroweak phase transition is approximately
described by adiabatic processes, distinguishing our scenario for electroweak
baryogenesis from the conventional ones. We show that, coupled to the
electroweak anomaly, the ALP can naturally realize spontaneous electroweak
baryogenesis to solve the matter-antimatter asymmetry problem for in the
range between about GeV and GeV. In such an ALP window, the
violation for baryogenesis is totally free from the experimental constraints,
especially from the recently improved limit on the electron electric dipole
moment. Future searches for ALPs could probe our scenario while revealing the
connection between electroweak symmetry breaking and baryogenesis.Comment: 12 pages, 5 figures, appendices added, published versio
Minimalist's Linux Cluster
Using barebone PC components and NIC's, we construct a linux cluster which
has 2-dimensional mesh structure. This cluster has smaller footprint, is less
expensive, and use less power compared to conventional linux cluster. Here, we
report our experience in building such a machine and discuss our current
lattice project on the machine.Comment: 3 pages, 2 figures, Proceedings of the Lattice 03 Conference
(Tsukuba, Japan
Entropic measure of directional emissions in microcavity lasers
We propose a noble notion of the directional emission in microcavity lasers.
First, Shannon entropy of the far-field profiles in the polar coordinate can
quantify the degree of unidirectionality of the emission, while previous
notions about the unidirectionality can not efficiently measure in the robust
range against a variation of the deformation parameter. Second, a divergence
angle of the directional emission is defined phenomenologically in terms of
full width at half maximum, and it is barely applicable to a complicated peak
structure. However, Shannon entropy of semi-marginal probability of the
far-field profiles in the cartesian coordinate can present equivalent results,
and moreover it is applicable to even the cases with a complicated peak
structure of the emission
An immunohistochemical study of the pancreatic endocrine cells of the ddN mouse.
The regional distribution and frequency of the pancreatic endocrine cells in the ddN mouse were studied using specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP). In the pancreatic islets, most of insulin-immunoreactive (IR) cells were located in the central region, and glucagon-, somatostatin and hPP-IR cells were located in the peripheral region regardless of the lobe. In the splenic part, glucagon-IR cells were also located in the central regions, and more numerous somatostatin-IR cells were detected in the central regions as compared with the duo-denal part. hPP-IR cells were restricted to the peripheral regions in both lobes but more numerous cells were detected in the duodenal portion. In the exocrine parenchyma of the splenic lobe, only insulin- and glucagon-IR cells were detected but all four kinds of IR cells were observed in the duodenal portion. In addition, insulin and hPP-IR cells were also demonstrated in the pancreatic duct regions. In conclusion, some strain-dependent characteristic distributional patterns of pancreatic endocrine cells were found in the ddN mouse with somewhat different distributional patterns between the two pancreatic lobes
Polymorphous Low-Grade Adenocarcinoma of the Tongue Base Treated by Transoral Robotic Surgery
Polymorphous low-grade adenocarcinoma is a rare malignancy arising from the minor salivary glands in the aerodigestive system, most frequently the hard palate. The treatment of choice is wide surgical resection, and the efficacy of radiotherapy has not been confirmed. A 54-year-old male presenting with a mass at the base of the tongue performed transoral laser microsurgery. The pathologic diagnosis was polymorphous low-grade adenocarcinoma. Complete surgical excision was performed via transoral robotic surgery without a flap reconstruction of the surgical defect. Without complications of bleeding or injury to the hypoglossal nerve, proper surgical margins were obtained, and no recurrence was found after 6 months after surgery. The patient did not complain of dysphagia or aspiration. We conclude that, in surgery for tongue base tumors with unknown malignant potential, transoral robotic surgery can be considered for achieving a definite resection avoiding a mandibulotomy without complications of dysphagia or aspiration after confirmation of malignancy with a frozen biopsy
Biomarkers of Oxidative Stress and Endogenous Antioxidants for Patients with Chronic Subjective Dizziness
As a neurotologic disorder of persistent non-vertiginous dizziness, chronic subjective dizziness (CSD) arises unsteadily by psychological and physiological imbalance. The CSD is hypersensitivity reaction due to exposure to complex motions visual stimuli. However, the pathophysiological features and mechanism of the CSD still remains unclearly. The present study was purposed to establish possible endogenous contributors of the CSD using serum samples from patients with the CSD. A total 199 participants were gathered and divided into two groups; healthy (n = 152, male for 61, and female for 91) and CSD (n = 47, male for 5, female for 42), respectively. Oxidative stress parameters such as, hydrogen peroxide and reactive substances were significantly elevated (p < 0.01 or p < 0.001), whereas endogenous antioxidant components including total glutathione contents, and activities of catalase and superoxide dismutase were significantly deteriorated in the CSD group (p < 0.01 or p < 0.001) as comparing to the healthy group, respectively. Serum levels of tumor necrosis factor -α and interferon-γ were significantly increased in the CSD participants (p < 0.001). Additionally, emotional stress related hormones including cortisol, adrenaline, and serotonin were abnormally observed in the serum levels of the CSD group (p < 0.01 or p < 0.001). Our results confirmed that oxidative stress and antioxidants are a critical contributor of pathophysiology of the CSD, and that is first explored to establish features of redox system in the CSD subjects compared to a healthy population
Decomposed entropy and estimation of output power in deformed microcavity lasers
Park et al. [Phys. Rev. A 106, L031504 (2022)] showed that the Shannon
entropy of the probability distribution of a single random variable for
far-field profiles (FFPs) in deformed microcavity lasers can efficiently
measure the directionality of deformed microcavity lasers. In this study, we
instead consider two random variables of FFPs with joint probability
distributions and introduce the decomposed (Shannon) entropy for the peak
intensity of directional emissions. This provides a new foundation such that
the decomposed entropy can estimate the degree of the output power at given
FFPs without any further information.Comment: 7 pages, 5 figure
Optimization of 4-Port Asymmetric Elliptical Birdcage RF Coil for 1.5 Tesla MRI
The elliptical whole-body radiofrequency (RF) coil can be used for RF transmission/reception in magnetic resonance (MR)-guided treatment or MR-fused system with space between the RF shield and the gradient coil available for other imaging/treatment modality. The elliptical birdcage has higher B1⁺ field uniformity than circular birdcage due to increased filling factor between the RF coil and target. In this work, the asymmetric elliptical birdcage is proposed to improve overall performance through electromagnetic simulations. This work compares the 2-port and 4-port excitations and their effects on B1⁺ field uniformity and SAR deposition for both circular and elliptical coil with symmetrical/asymmetrical structures
Development of an Emergency Locking Unit for a Belt-In-Seat (BIS) System Using a MEMS Acceleration Sensor
This paper proposes an emergency locking unit (ELU) for a seat belt retractor which is mounted on the back frame of a vehicle seat. The proposed unit uses a recliner sensor based on a MEMS acceleration sensor and solenoid mechanism. The seat has an upper frame supported to tilt on a lower frame. The retractor in belt in seat (BIS) system is supported by the upper frame. The proposed recliner sensor based on a MEMS acceleration sensor comprises orientation means for maintaining a predetermined orientation of emergency relative to the lower frame independently of the force of gravity when the upper frame tilts on the lower frame. Experimental results show that the developed recliner sensor unit operates effectively with respect to rollover angles. Thus, the developed unit will have a considerable potential to offer a new design concept in BIS system
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