151 research outputs found
Scalar Gravitational Waves Can Be Generated Even Without Direct Coupling Between Dark Energy and Ordinary Matter
We point out, the scalar sector of gravitational perturbations may be excited
by an isolated astrophysical system immersed in a universe whose accelerated
expansion is not due to the cosmological constant, but due to extra field
degrees of freedom. This is true even if the source of gravitational radiation
did not couple directly to these additional fields. We illustrate this by
considering a universe driven by a single canonical scalar field. By working
within the gauge-invariant formalism, we solve for the electric components of
the linearised Weyl tensor to demonstrate that both the gravitational massless
spin-2 (transverse-traceless) tensor and the (Bardeen) scalar modes are
generated by a generic astrophysical source. For concreteness, the Dark Energy
scalar field is either released from rest, or allowed to asymptote to the
minimum in a certain class of potentials; and we compute the traceless tidal
forces induced by gravitational radiation from a hypothetical compact binary
system residing in such a universe. Though their magnitudes are very small
compared to the tensors', spin zero gravitational waves in such a canonical
scalar driven universe are directly sensitive to both the Dark Energy equation
of state and the eccentricity of the binary's orbit.Comment: 28 pages, 2 figure
UPS 2.0: unique probe selector for probe design and oligonucleotide microarrays at the pangenomic/ genomic level
<p>Abstract</p> <p>Background</p> <p>Nucleic acid hybridization is an extensively adopted principle in biomedical research, in which the performance of any hybridization-based method depends on the specificity of probes to their targets. To determine the optimal probe(s) for detecting target(s) from a sample cocktail, we developed a novel algorithm, which has been implemented into a web platform for probe designing. This probe design workflow is now upgraded to satisfy experiments that require a probe designing tool to take the increasing volume of sequence datasets.</p> <p>Results</p> <p>Algorithms and probe parameters applied in UPS 2.0 include GC content, the secondary structure, melting temperature (Tm), the stability of the probe-target duplex estimated by the thermodynamic model, sequence complexity, similarity of probes to non-target sequences, and other empirical parameters used in the laboratory. Several probe background options,<b><it>Unique probe within a group</it></b><it>,</it><b><it>Unique probe in a specific Unigene set</it></b><it>,</it><b><it>Unique probe based onthe pangenomic level</it></b><it>,</it> and <b><it>Unique Probe in the user-defined genome/transcriptome</it></b><it>,</it> are available to meet the scenarios that the experiments will be conducted. Parameters, such as salt concentration and the lower-bound Tm of probes, are available for users to optimize their probe design query. Output files are available for download on the result page. Probes designed by the UPS algorithm are suitable for generating microarrays, and the performance of UPS-designed probes has been validated by experiments.</p> <p>Conclusions</p> <p>The UPS 2.0 evaluates probe-to-target hybridization under a user-defined condition to ensure high-performance hybridization with minimal chance of non-specific binding at the pangenomic and genomic levels. The UPS algorithm mimics the target/non-target mixture in an experiment and is very useful in developing diagnostic kits and microarrays. The UPS 2.0 website has had more than 1,300 visits and 360,000 sequences performed the probe designing task in the last 30 months. It is freely accessible at <url>http://array.iis.sinica.edu.tw/ups/.</url></p> <p>Screen cast: <url>http://array.iis.sinica.edu.tw/ups/demo/demo.htm</url></p
A Reinforcement Learning Badminton Environment for Simulating Player Tactics (Student Abstract)
Recent techniques for analyzing sports precisely has stimulated various
approaches to improve player performance and fan engagement. However, existing
approaches are only able to evaluate offline performance since testing in
real-time matches requires exhaustive costs and cannot be replicated. To test
in a safe and reproducible simulator, we focus on turn-based sports and
introduce a badminton environment by simulating rallies with different angles
of view and designing the states, actions, and training procedures. This
benefits not only coaches and players by simulating past matches for tactic
investigation, but also researchers from rapidly evaluating their novel
algorithms.Comment: Accepted by AAAI 2023 Student Abstract, code is available at
https://github.com/wywyWang/CoachAI-Projects/tree/main/Strategic%20Environmen
Association of metabolic syndrome with erosive esophagitis and Barrett’s esophagus in a Chinese population
AbstractBackgroundMetabolic syndrome has been highlighted as a risk factor for several gastrointestinal diseases, including gastroesophageal reflux disease and Barrett’s esophagus (BE). The aim of this study was to investigate the association of metabolic syndrome with erosive esophagitis (EE) and BE.MethodsData were retrospectively collected from patients who visited the Medical Screening Center at Taichung Veterans General Hospital, Taichung, Taiwan from January 2006 to December 2009. All patients underwent an open-access transoral upper gastrointestinal endoscopy, and serum laboratory data were collected. The exclusion criteria included prior gastric surgery, or presence of esophageal varices or peptic ulcers. These patients were assigned to groups according to their endoscopic findings as follows: (1) normal group; (2) EE group; and (3) BE group. Metabolic syndrome was diagnosed based on the International Diabetes Federation criteria.ResultsThere were 560/6499 (8.6%) patients, 214/1118 (9.6%) patients, and 19/95 (20%) patients with metabolic syndrome in the normal, EE, and BE groups, respectively. There was a significantly higher percentage of cases with hypertriglyceridemia in the EE group (67%) compared with the other groups. The BE group had significantly higher rates of central obesity (33%) and hypertension (29.5%) compared with rates in the normal and EE groups. After adjusting for confounders, the positive association with metabolic syndrome still existed in both the EE group (adjusted odds ratio=2.43; 95% confidence interval=1.02–3.44) and the BE group (adjusted odds ratio=2.82; 95% confidence interval=2.05–3.88).ConclusionOur research indicated that in fact there is a greater risk of concurrent metabolic syndrome in patients with EE or BE
DNIC-mediated analgesia produced by a supramaximal electrical or a high-dose formalin conditioning stimulus: roles of opioid and α2-adrenergic receptors
- …