12,096 research outputs found
Study on Two Coupled Relativistic Superfluids with Spontaneous Symmetry Breaking
In this paper, we have studied two coupled relativistic superfluids with
spontaneous U(1) symmetry breaking, using Poisson bracket technique. After
constructing the commutators between thermo-quantities and field quantities,
the equations of motion are obtained. These equations describe the system in
the frame of two-constituent superfluid theory and provide a clear picture
relating the symmetry breaking and the physical quantities explicitly. The
interference effect is discussed and the Josephson-type equation is also given.
Furthermore, the dissipation effect and entropy production mechanism are
presented and the dissipative coefficients are given explicitly in the
first-order theory framework.Comment: 12 page
A Model for Investigating Developmental Eye Repair in Xenopus Laevis
Vertebrate eye development is complex and requires early interactions between neuroectoderm and surface ectoderm during embryogenesis. In the African clawed frog, Xenopus laevis, individual eye tissues such as the retina and lens can undergo regeneration. However, it has been reported that removal of either the specified eye field at the neurula stage or the eye during tadpole stage does not induce replacement. Here we describe a model for investigating Xenopus developmental eye repair. We found that tailbud embryos can readily regrow eyes after surgical removal of over 83% of the specified eye and lens tissues. The regrown eye reached a comparable size to the contralateral control by 5 days and overall animal development was normal. It contained the expected complement of eye cell types (including the pigmented epithelium, retina and lens), and is connected to the brain. Our data also demonstrate that apoptosis, an early mechanism that regulates appendage regeneration, is also required for eye regrowth. Treatment with apoptosis inhibitors (M50054 or NS3694) blocked eye regrowth by inhibiting caspase activation. Together, our findings indicate that frog embryos can undergo successful eye repair after considerable tissue loss and reveals a required role for apoptosis in this process. Furthermore, this Xenopus model allows for rapid comparisons of productive eye repair and developmental pathways. It can also facilitate the molecular dissection of signaling mechanisms necessary for initiating repair
On the Estimation of the Mission Performance Index of Unmanned Surface Vehicles Based on the Mission Coverage Area
For mission planning and replanning of multiple unmanned surface vehicles (USVs), it is important to estimate each USV’s mission performance in terms of sea surveillance (e.g., illegal ship control). In this study, a mission performance index (MPI) is proposed based on the mission coverage area for estimating the USVs’ mission performance of illegal ship control. The penalty value is considered in the MPI calculation procedure owing to the track-off of the USV. In addition, the USV simulation is conducted under illegal ship control, and the MPI is calculated based on changing the mission coverage area. The results show that the MPI increases with the path width of the mission coverage area
Effect of Outlier Removal from Temporal ASF Corrections on Multichain Loran Positioning Accuracy
The widely used global navigation satellite systems (GNSSs) are vulnerable to
radio frequency interference (RFI). Long-range navigation (Loran), a
terrestrial navigation system, can compensate for this weakness; however, it
suffers from low positioning accuracy, and studies are under way to improve its
positioning performance. One such study has proposed the multichain Loran
positioning method that uses the signals of transmitting stations belonging to
different chains. Although the multichain Loran positioning performance is
superior to the performance of conventional methods, the additional secondary
factor (ASF) can still degrade its positioning accuracy. To mitigate the
effects of temporal ASF, which is one of the ASF components, it is necessary to
obtain temporal correction data from a nearby reference station at a known
location. In this study, an experiment is performed to verify the effect of
removing the outliers in the temporal correction data on the multichain Loran
positioning accuracy.Comment: Submitted to ICCAS 202
Fluid Pressure-Activated Non-Selective Cation Current and Cl- Current in Rat Atrial Myocytes
AAD-2004, a potent spin trapping molecule and microsomal prostaglandin E synthase-1 inhibitor, shows safety and efficacy in a mouse model of ALS
While free radicals and inflammation constitute major routes of neuronal injury occurring in neurodegenerative diseases, neither antioxidants nor nonsteroidal anti-inflammatory drugs (NSAIDs) have shown significant efficacy in human clinical trials. To explore the possibility that concurrent blockade of free radicals and PGE2-mediated inflammation might constitute a safe and effective therapeutic approach to certain neurodegenerative diseases, we have developed 2-hydroxy-5-[2-(4-trifluoromethylphenyl)-ethylaminobezoic acid (AAD-2004) as a derivative of aspirin. AAD-2004 completely removed free radicals at 50 nM as a potent spin trapping molecule and inhibited microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 230 nM. Oral administration of AAD-2004 blocked free radical formation, PGE2 formation, and microglial activation in the spinal motor neurons of SOD1G93A mice. As a consequence, AAD-2004 reduced autophagosome formation, axonopathy, and motor neuron degeneration, improving motor function and increasing life span. In these assays, AAD-2004 was superior to ibuprofen or riluzole. Gastric bleeding was not induced by AAD-2004 even at a dose 400-fold higher than that required to obtain maximal therapeutic efficacy in SOD1G93A mice. Targeting both mPGES-1 and free radicals may be a promising approach to reduce neurodegeneration in ALS and possibly other neurodegenerative diseases
GaN-based sensor nodes for in situ detection of gases
A system for detecting chemical/biological substances and a detection method. The system comprises a plurality of sensing units or nodes and a radiofrequency link. Each unit has several sensors with different sensing curves. Each sensor is able to transmit information related to the sensed substance on a specific frequency. The sensors preferably comprise AlGaN/GaN high electron mobility transistors
Three Qualities of OTT Services: A Mixed Methods Approach
Since over-the-top (OTT) services emerged as a new way of consuming video contents, OTT markets have grown exponentially and the competition among the OTT services has been intensified. Nonetheless, only limited scholarly attention has been paid to identifying user’s motivation to use OTT service. Therefore, we employ a developmental sequential mixed methods approach to identify quality factors and to examine their effect on post-subscription experiences and continuance intention. In a qualitative study, we derived six factors that are important to users’ intention to continue to use the subscription. Based on the identified factors, we develop a research model with three groups of qualities modified from IS success model. The proposed research model will be validated with data collected through a quantitative research with a survey to OTT service users
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