220 research outputs found
Thermal welding of an unstable thermoplastic facilitated by a diffusion-promoting interlayer
A study into the feasibility of thermal welding of an unstable thermoplastic has been
undertaken. A heater wire embedded in a diffusion promoting interlayer has been
used to accelerate interdiffusion between two poly(vinylchloride) (PVC) plaques.
Interlayers consisted of a compatible vinyl resin and a plasticiser. Both normal
resistance and an isothermal induction process were used as heat sources, with lap
shear testing used to determine the strength of such systems. Vickers hardness testing
has been used to ascertain the extent of diffusion and immersion diffusion testing was
used to find the activation energy for the process. Micro thermal analysis (MTA) in
conjunction with laser induced mass analysis (LIMA), ultra-violet fluorescence
microscopy and microscopic infrared techniques were used to study degradation. It
has been found that the use of an interlayer allows thermal welding of PVC without
deleterious degradation. The concentration and type of plasticiser was found critical
in producing a strong weld. Low concentrations of plasticiser did not cause sufficient
diffusion and high concentrations of plasticiser in the interlayer produced a weak
interface; the optimum amount was dependent on the diffusion coefficient of the
plasticiser. Fast fusing plasticisers resulted in higher lap shear strength because they
cause a greater extent of diffusion during a constant welding time than slower fusing
plasticisers. Degradation products were detected in proximity to the heater wire.
Resistance heating was found to cause an exponential increase in degradation closer
to the wire while isothermal heating produced a degradation profile with a plateau
region next to the heater wire
The Fear of Femininity vs. the Fear of Death and Attitudes Towards Lesbians and Gay Men
Decades of research on attitudes toward non-heterosexuals has found that heterosexual males are significantly more negative towards gay men than lesbians, while females generally have similar attitudes toward both. Using a terror management research design, the current research investigates the influence of the fear of femininity and the fear of mortality on attitudes toward gay men and lesbians. Two hundred forty-seven introductory psychology students were primed to fear their own mortality, their femininity or masculinity, or dental pain. Sexual prejudice scores were consistent with prior research, but the findings were not consistent with either a mortality salience effect or femininity salience effect. Women primed to fear their own masculinity had the lowest sexual prejudice scores indicating a possible empathic response. Heterosexual women’s attitudes toward gay men were influenced by the order of presentation, indicating a possible covert bias not found in self-report measures
Detecting reactivity
Author Posting. © Ecological Society of America, 2009. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 90 (2009): 2683-2688, doi:10.1890/08-2014.1.By definition, ecological systems at a stable equilibrium eventually return to the equilibrium point following a small perturbation. In the short term, however, perturbations can grow. Equilibria that exhibit transient growth following perturbation are said to be reactive. In this report, we present a statistical method for detecting reactivity from multivariate time series. The test is simple and computationally tractable, and it can be applied to short time series. Its main limitation is that it is based on a model of population dynamics that is linear on a logarithmic scale. Our results suggest that the test is robust when the dynamics are nonlinear on the log scale but that it may incorrectly classify an equilibrium as reactive when the reactivity is close to zero.This research was supported by a grant (DEB-0515639) from
the U.S. National Science Foundation
Degradation studies of crosslinked polyethylene. 2, Aged in water
Silane crosslinking of polyethylene was carried out by grafting an organofunctional silane
(vinyltrimethoxysilane) onto polyethylene and by subsequent moisture crosslinking in hot water
using a tin catalyst. This study focuses on the degradation processes, which occurred in the
material after water ageing in an autoclave; ageing temperatures ranged from 90 to 190°C, while
ageing times ranged from 2h to 500h. Significant changes in the chemical structure of the
material were observed by FTIR, as carbonyl group concentration increased and different
structures formed in the region of absorbance of groups containing silicone; the structural
changes affected significantly the mechanical properties as shown by the tensile data. A
chemical analysis of the extracts in chloroform of water aged samples carried out by using
FTIR, LIMA and GPC techniques and some optical microscopy evidence, suggested that the
mechanism of degradation in water is different from the one in air, as during water ageing the
antioxidants are washed away by water and hydrolytic oxidation also occurs. ECHIP
experimental design software was used in order to optimise the number of experimental trials
and to model the results obtained.
Keywords: PE-crosslink, water ageing, carbonyl ratio, silane, antioxidants
Degradation studies of crosslinked polyethylene. 1, Aged in air
Silane crosslinking of polyethylene, carried out by grafting an organofunctional silane
(vinyltrimethoxysilane) onto polyethylene and by subsequent moisture crosslinking in hot water
using a tin catalyst, has been widely used in industrial applications because of its advantages in
terms of low cost and easy processing. This study focused on the degradation processes which
occurred in the material after air ageing in an oven; temperatures ranged from 90 to 220°C,
while ageing times ranged from 2h to 500h. Significant structural changes were observed
according to the different ageing conditions (below and above the melting region of the
material), since the carbonyl group concentration increased substantially during ageing above
the melting region and the silicone containing groups were also affected by the degradation.
These structural changes affected the mechanical and thermal properties of the material, which
was annealed at lower ageing temperatures (up to 155°C) and highly degraded at higher
temperatures, when C-C crosslinks formed. Experimental design software was used in order to
optimise the number of experimental trials and to model the results obtained; its analysis
contributed to the interpretation of the results
A Pilot Survey for the HO Southern Galactic Plane Survey (HOPS)
We describe observations with the Mopra radiotelescope designed to assess the
feasibility of the HO maser southern Galactic plane survey (HOPS). We
mapped two one-square-degree regions along the Galactic plane using the new 12
mm receiver and the UNSW Mopra spectrometer (MOPS). We covered the entire
spectrum between 19.5 and 27.5 GHz using this setup with the main aims of
finding out which spectral lines can be detected with a quick mapping survey.
We report on detected emission from HO masers, NH inversion transitions
(1,1), (2,2) and (3,3), HCN (3-2), as well as several radio recombination
lines.Comment: accepted by PAS
Verifying head impacts recorded by a wearable sensor using video footage in rugby league: A preliminary study
Background: Rugby league is a full-contact collision sport with an inherent risk of concussion. Wearable instrumented technology was used to observe and characterize the level of exposure to head impacts during game play.
Purpose: To verify the impacts recorded by the x-patch™ with video analysis.
Study design: Observational case series.
Methods: The x-patch™ was used on eight men’s semi-professional rugby league players during the 2016 Newcastle Rugby League competition (five forwards and three backs). Game day footage was recorded by a trained videographer using a single camera located at the highest midfield location to verify the impact recorded by the x-patch™. Videographic and accelerometer data were time synchronized.
Results: The x-patch™ sensors recorded a total of 779 impacts ≥ 20 g during the games, of which 732 (94.0%) were verified on video. In addition, 817 impacts were identified on video that did not record an impact on the sensors. The number of video-verified impacts ≥ 20 g, per playing hour, was 7.8 for forwards and 4.8 for backs (range = 3.9–19.0). Impacts resulting in a diagnosed concussion had much greater peak linear acceleration (M = 76.1 g, SD = 17.0) than impacts that did not result in a concussion (M = 34.2g, SD = 18.0; Cohen’s d = 2.4).
Conclusions: The vast majority (94%) of impacts ≥ 20 g captured by the x-patch™ sensor were video verified in semi-professional rugby league games. The use of a secondary source of information to verify impact events recorded by wearable sensors is beneficial in clarifying game events and exposure levels
Recurrent De Novo NAHR Reciprocal Duplications in the ATAD3 Gene Cluster Cause a Neurogenetic Trait with Perturbed Cholesterol and Mitochondrial Metabolism
Recent studies have identified both recessive and dominant forms of mitochondrial disease that result from ATAD3A variants. The recessive form includes subjects with biallelic deletions mediated by non-allelic homologous recombination. We report five unrelated neonates with a lethal metabolic disorder characterized by cardiomyopathy, corneal opacities, encephalopathy, hypotonia, and seizures in whom a monoallelic reciprocal duplication at the ATAD3 locus was identified. Analysis of the breakpoint junction fragment indicated that these 67 kb heterozygous duplications were likely mediated by non-allelic homologous recombination at regions of high sequence identity in ATAD3A exon 11 and ATAD3C exon 7. At the recombinant junction, the duplication allele produces a fusion gene derived from ATAD3A and ATAD3C, the protein product of which lacks key functional residues. Analysis of fibroblasts derived from two affected individuals shows that the fusion gene product is expressed and stable. These cells display perturbed cholesterol and mitochondrial DNA organization similar to that observed for individuals with severe ATAD3A deficiency. We hypothesize that the fusion protein acts through a dominant-negative mechanism to cause this fatal mitochondrial disorder. Our data delineate a molecular diagnosis for this disorder, extend the clinical spectrum associated with structural variation at the ATAD3 locus, and identify a third mutational mechanism for ATAD3 gene cluster variants. These results further affirm structural variant mutagenesis mechanisms in sporadic disease traits, emphasize the importance of copy number analysis in molecular genomic diagnosis, and highlight some of the challenges of detecting and interpreting clinically relevant rare gene rearrangements from next-generation sequencing data.This article is freely available via Open Access. Click on the publisher URL to access it via the publisher's site.We acknowledge funding from Wellcome ( 200990 ). S.E. is a Wellcome Senior Investigator. U.F.P. is supported by a predoctoral fellowship from the Basque Government ( PRE_2018_1_0253 ). M.M.O. is supported by a predoctoral fellowship from the University of the Basque Country ( UPV/EHU, PIF 2018 ). I.J.H. is supported by the Carlos III Health Program ( PI17/00380 ), and País Vasco Department of Health ( 2018111043 ; 2018222031 ). A.S. is supported by the UK Medical Research Council with a Senior Non-Clinical Fellowship ( MC_PC_13029 ). T. Harel is supported by the Israel Science Foundation grant 1663/17 . W.H.Y. is supported by the National Institute of General Medical Sciences of the National Institutes of Health through grant 5 P20 GM103636-07 . J.R.L. is supported by the US National Institute of Neurological Disorders and Stroke ( R35NS105078 ), the National Institute of General Medical Sciences ( R01GM106373 ), and the National Human Genome Research Institute and National Heart Lung and Blood Institute (NHGRI/NHBLI) to the Baylor-Hopkins Center for Mendelian Genomics (BHCMG, UM1 HG006542 ). R.W.T. is supported by the Wellcome Centre for Mitochondrial Research ( 203105/Z/16/Z ), the Medical Research Council (MRC) International Centre for Genomic Medicine in Neuromuscular Disease , Mitochondrial Disease Patient Cohort (UK) ( G0800674 ), the UK NIHR Biomedical Research Centre for Aging and Age-related disease award to the Newcastle upon Tyne Foundation Hospitals NHS Trust, the MRC/EPSRC Molecular Pathology Node , The Lily Foundation , and the UK NHS Highly Specialised Service for Rare Mitochondrial Disorders of Adults and Children . The DDD study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003). This study makes use of DECIPHER, which is funded by Wellcome. See Nature PMID: 25533962 or https://www.ddduk.org/access.html for full acknowledgment.pre-print, post-print (6 month embargo
Rab-coupling protein coordinates recycling of α5β1 integrin and EGFR1 to promote cell migration in 3D microenvironments
Here we show that blocking the adhesive function of αvβ3 integrin with soluble RGD ligands, such as osteopontin or cilengitide, promoted association of Rab-coupling protein (RCP) with α5β1 integrin and drove RCP-dependent recycling of α5β1 to the plasma membrane and its mobilization to dynamic ruffling protrusions at the cell front. These RCP-driven changes in α5β1 trafficking led to acquisition of rapid/random movement on two-dimensional substrates and to a marked increase in fibronectin-dependent migration of tumor cells into three-dimensional matrices. Recycling of α5β1 integrin did not affect its regulation or ability to form adhesive bonds with substrate fibronectin. Instead, α5β1 controlled the association of EGFR1 with RCP to promote the coordinate recycling of these two receptors. This modified signaling downstream of EGFR1 to increase its autophosphorylation and activation of the proinvasive kinase PKB/Akt. We conclude that RCP provides a scaffold that promotes the physical association and coordinate trafficking of α5β1 and EGFR1 and that this drives migration of tumor cells into three-dimensional matrices
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