1,293 research outputs found
Strengthening Mechanism of Short Glass Fiber Reinforced Plastic Foam
This study deals with new ideas in composite material technology. Specifically it is a representation of work done to improve the physical strength and stiffness properties of a cellular plastic by reinforcing it with short chopped glass fibers. Previous work has been examined to discover what has been accomplished in the area of fracture mechanics and the reasons for improved properties of the fiber filled material over the unfilled matrix. Several ideas are presented which suggest a different or modified fracture mechanism over what was gleaned out of the literature. Tests were performed to check their validity.Mechanical Engineerin
Being prepared for emotionally demanding research
Research on topics such as child sexual abuse can be emotionally demanding for researchers in ways that surpass many other lines of work. Burrell et al. draw on their own experience to offer recommendations that may help increase researchersâ resilience to these challenges
Guidelines for Carotid Endarterectomy: a Statement for Healthcare Professionals From a Special Writing Group of the Stroke Council, American Heart Association.
Theories of American Imperialism: A Critical Evaluation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68828/2/10.1177_048661347400600303.pd
Expanding the genotypic spectrum of TXNL4A variants in BurnâMcKeown syndrome
From Wiley via Jisc Publications RouterHistory: received 2021-09-06, rev-recd 2021-10-21, accepted 2021-10-23, pub-electronic 2021-11-05Article version: VoRPublication status: PublishedFunder: Biotechnology and Biological Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000268; Grant(s): BB/N000358/1Funder: Health Education England Genomics Education ProgrammeFunder: Medical Research Council; Id: http://dx.doi.org/10.13039/501100007155; Grant(s): 1916606Funder: National Institute for Health Manchester Biomedical Research Centre; Grant(s): ISâBRCâ1215â20007Abstract: The developmental disorder BurnâMcKeown Syndrome (BMKS) is characterised by choanal atresia and specific craniofacial features. BMKS is caused by biallelic variants in the preâmessenger RNA splicing factor TXNL4A. Most patients have a lossâofâfunction variant in trans with a 34âbase pair (bp) deletion (type 1 Î34) in the promoter region. Here, we identified two patients with BMKS. One individual has a TXNL4A c.93_94delCC, p.His32Argfs *21 variant combined with a type 1 Î34 promoter deletion. The other has an intronic TXNL4A splice site variant (c.258â3C>G) and a type 1 Î34 promoter deletion. We show the c.258â3C>G variant and a previously reported c.258â2A>G variant, cause skipping of the final exon of TXNL4A in a minigene splicing assay. Furthermore, we identify putative transcription factor binding sites within the 56 bp of the TXNL4A promoter affected by the type 1 and type 2 Î34 and use dual luciferase assays to identify a 22 bp repeated motif essential for TXNL4A expression within this promoter region. We propose that additional variants affecting critical transcription factor binding nucleotides within the 22 bp repeated motif could be relevant to BMKS aetiology. Finally, our data emphasises the need to analyse the nonâcoding sequence in individuals where a single likely pathogenic coding variant is identified in an autosomal recessive disorder consistent with the clinical presentation
Guidelines for developing optical clocks with fractional frequency uncertainty
There has been tremendous progress in the performance of optical frequency
standards since the first proposals to carry out precision spectroscopy on
trapped, single ions in the 1970s. The estimated fractional frequency
uncertainty of today's leading optical standards is currently in the
range, approximately two orders of magnitude better than that of the best
caesium primary frequency standards. This exceptional accuracy and stability is
resulting in a growing number of research groups developing optical clocks.
While good review papers covering the topic already exist, more practical
guidelines are needed as a complement. The purpose of this document is
therefore to provide technical guidance for researchers starting in the field
of optical clocks. The target audience includes national metrology institutes
(NMIs) wanting to set up optical clocks (or subsystems thereof) and PhD
students and postdocs entering the field. Another potential audience is
academic groups with experience in atomic physics and atom or ion trapping, but
with less experience of time and frequency metrology and optical clock
requirements. These guidelines have arisen from the scope of the EMPIR project
"Optical clocks with uncertainty" (OC18). Therefore, the
examples are from European laboratories even though similar work is carried out
all over the world. The goal of OC18 was to push the development of optical
clocks by improving each of the necessary subsystems: ultrastable lasers,
neutral-atom and single-ion traps, and interrogation techniques. This document
shares the knowledge acquired by the OC18 project consortium and gives
practical guidance on each of these aspects
Three Warm Jupiters around Solar-analog Stars Detected with TESS*
We report the discovery and characterization of three giant exoplanets orbiting solar-analog stars, detected by the TESS space mission and confirmed through ground-based photometry and radial velocity measurements taken at La Silla observatory with FEROS. TOI-2373 b is a warm Jupiter orbiting its host star every âŒ13.3 days, and is one of the most massive known exoplanet with a precisely determined mass and radius around a star similar to the Sun, with an estimated mass of m _p = and a radius of r _p = . With a mean density of , TOI-2373 b is among the densest planets discovered so far. TOI-2416 b orbits its host star on a moderately eccentric orbit with a period of âŒ8.3 days and an eccentricity of e = . TOI-2416 b is more massive than Jupiter with m _p = , however is significantly smaller with a radius of r _p = , leading to a high mean density of . TOI-2524 b is a warm Jupiter near the hot Jupiter transition region, orbiting its star every âŒ7.2 days on a circular orbit. It is less massive than Jupiter with a mass of m _p = , and is consistent with an inflated radius of r _p = , leading to a low mean density of . The newly discovered exoplanets TOI-2373 b, TOI-2416 b, and TOI-2524 b have estimated equilibrium temperatures of K, K, and K, respectively, placing them in the sparsely populated transition zone between hot and warm Jupiters
ÎČ-alanine supplementation improves in-vivo fresh and fatigued skeletal muscle relaxation speed
Purpose: In fresh muscle, supplementation with the rate-limiting precursor of carnosine, ÎČ-alanine (BA), results in a decline in muscle half-relaxation time (HRT) potentially via alterations to calcium (Ca2+) handling. Accumulation of hydrogen cation (H+) has been shown to impact Ca2+ signalling during muscular contraction, carnosine has the potential to serve as a cytoplasmic regulator of Ca2+ and H+ coupling, since it binds to both ions. The present study examined the effect of BA supplementation on intrinsic in-vivo isometric knee extensor force production and muscle contractility in both fresh and fatigued human skeletal muscle assessed during voluntary and electrically evoked (nerve and superficial muscle stimulation) contractions. Methods: Twenty-three males completed two experimental sessions, pre- and post- 28 day supplementation with 6.4Â g.dayâ1 of BA (n=12) or placebo (PLA; n=11). Isometric force was recorded during a series of voluntary and electrically evoked knee extensor contractions. Results: BA supplementation had no effect on voluntary
or electrically evoked isometric force production, or
twitch electromechanical delay and time-to-peak tension.
There was a significant decline in muscle HRT in fresh and fatigued muscle conditions during both resting (3±13%; 19±26%) and potentiated (1±15%; 2±20%) twitch
contractions. Conclusions: The mechanism for reduced HRT in fresh and fatigued skeletal muscle following BA supplementation is unclear. Due to the importance of muscle relaxation on total energy consumption, especially during short, repeated contractions, BA supplementation may prove to be beneficial in minimising contractile slowing induced by fatigue. Trial registration The trial is registered with Clinicaltrials.gov, ID number NCT02819505
New hyperekplexia mutations provide insight into glycine receptor assembly, trafficking, and activation mechanisms
Background: Hyperekplexia mutations have provided much information about glycine receptor structure and function. Results: Weidentified and characterized nine new mutations. Dominant mutations resulted in spontaneous activation, whereas recessive mutations precluded surface expression. Conclusion: These data provide insight into glycine receptor activation mechanisms and surface expression determinants. Significance: The results enhance our understanding of hyperekplexia pathology and glycine receptor structure-function. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A
Analysis of LMNB1 Duplications in Autosomal Dominant Leukodystrophy Provides Insights into Duplication Mechanisms and Allele-Specific Expression
- âŠ