1,052 research outputs found
Soluble pre-fibrillar tau and β-amyloid species emerge in early human Alzheimer’s disease and track disease progression and cognitive decline
Acknowledgments We would like to gratefully acknowledge all donors and their families for the tissue provided for this study. Human tissue samples were supplied by the Brains for Dementia Research programme, jointly funded by Alzheimer’s Research UK, the Alzheimer’s Society and the Medical Research Council, and sourced from the MRC London Neurodegenerative Diseases Brain Bank, the Manchester Brain Bank, the South West Dementia Brain Bank (SWDBB), the Newcastle Brain Tissue Resource and the Oxford Brain Bank. The Newcastle Brain Tissue Resource and Oxford Brain Bank are also supported by the National Institute for Health Research (NIHR) Units. The South West Dementia Brain Bank (SWDBB) receives additional support from BRACE (Bristol Research into Alzheimer’s and Care of the Elderly). Alz-50, CP13, MC-1 and PHF-1 antibodies were gifted from Dr. Peter Davies and brain lystates from BACE1−/−mice were obtained from Prof Mike Ashford. The work presented here was funded by Alzheimer’s Research UK (Grant refs: ARUKPPG2014A-21 and ARUK-NSG2015-1 to BP and DK and NIH/NIA grants NIH/NINDS R01 NS082730 and R01 AG044372 to NK)Peer reviewedPublisher PD
The Effect of Thin Film Adhesives on Mode II Interlaminar Fracture Toughness in Carbon Fiber Composites with Shape Memory Alloy Inserts
A single sheet of nickel-titanium (NiTi) shape memory alloy (SMA) was introduced within an IM7/8552 polymer matrix composite (PMC) panel in conjunction with multiple thin film adhesives to promote the interfacial bond strength between the SMA and PMC. End notched flexure (ENF) testing was performed in accordance to ASTM D7905 method for evaluation of mode II interlaminar fracture toughness (GIIC) of unidirectional fiber-reinforced polymer matrix composites. Acoustic emissions (AE) were monitored during testing with two acoustic sensors attached to the specimens. The composite panels examined using scanning electron microscopy techniques after part failure. GIIC values for the control composite samples were found to be higher than those of samples with embedded SMA sheets. The presence of adhesives bonded to SMA sheets further diminished the GIIC values. AE values revealed poor bonding of the panels, with little to no signals during testing
Two new pulsating low-mass pre-white dwarfs or SX Phenix stars?*
Context. The discovery of pulsations in low-mass stars opens an opportunity
for probing their interiors and to determine their evolution, by employing the
tools of asteroseismology. Aims. We aim to analyze high-speed photometry of
SDSSJ145847.02070754.46 and SDSSJ173001.94070600.25 and discover
brightness variabilities. In order to locate these stars in the diagram we fit optical spectra (SDSS) with synthetic non-magnetic
spectra derived from model atmospheres. Methods. To carry out this study, we
used the photometric data obtained by us for these stars with the 2.15m
telescope at CASLEO, Argentina. We analyzed their light curves and we apply the
Discrete Fourier Transform to determine the pulsation frequencies. Finally, we
compare both stars in the diagram, with known two
pre-white dwarfs, seven pulsating pre-ELM white dwarf stars, Scuti and
SX Phe stars. Results. We report the discovery of pulsations in
SDSSJ145847.02070754.46 and SDSSJ173001.94070600.25. We determine their
effective temperature and surface gravity to be = 7 972 200
K, = 4.25 0.5 and = 7 925 200 K, =
4.25 0.5, respectively. With these parameters these new pulsating
low-mass stars can be identified with either ELM white dwarfs (with ~ 0.17 Mo)
or more massive SX Phe stars. We identified pulsation periods of 3 278.7 and 1
633.9 s for SDSSJ145847.02070754.46 and a pulsation period of 3 367.1 s for
SDSSJ173001.94070600.25. These two new objects together with those of Maxted
et al. (2013, 2014) indicate the possible existence of a new instability domain
towards the late stages of evolution of low-mass white dwarf stars, although
their identification with SX Phe stars cannot be discarded.Comment: 5 pages, 5 figures, 1 table, accepted for publication in A&A
Openness Personality Trait Associated With Benefit From a Nonpharmacological Breathlessness Intervention in People With Intrathoracic Cancer: An Exploratory Analysis
Context: Breathlessness is common in people with lung cancer. Nonpharmacological breathlessness interventions reduce distress because of and increase mastery over breathlessness. Objectives: Identify patient characteristics associated with response to breathlessness interventions. Methods: Exploratory secondary trial data analysis. Response defined as a one-point improvement in 0–10 Numerical Rating Scale of worst breathlessness/last 24 hours (response—worst) or a 0.5-point improvement in the Chronic Respiratory Questionnaire (CRQ) mastery (response—mastery) at four weeks. Univariable regression explored relationships with plausible demographic, clinical, and psychological variables followed by multivariable regression for associated (P < 0.05) variables. Results: About 158 participants with intrathoracic cancer (mean age 69.4 [SD 9.35] years; 40% women) were randomized to one or three breathlessness training sessions. About 91 participants had evaluable data for response—worst and 107 for response—mastery. In the univariable analyses, the personality trait openness was associated with response—worst (odds ratio [OR] 1.99 [95% CI 1.08–3.67]; P = 0.028) and response—mastery (OR 1.84 [95% CI 1.04–3.23]; P = 0.035). Higher CRQ—fatigue (OR 0.61 [95% CI 0.41–0.91]; P = 0.015), CRQ—emotion (OR 0.68 [95% CI 0.47–0.96]; P = 0.030), and worse CRQ—mastery (OR 0.61 [95% CI 0.42–0.88]; P = 0.008), and the presence of metastases and fatigue were associated with reduced odds of response—mastery. In the adjusted response—mastery model, only openness remained (OR 1.73 [95% CI 0.95–3.15]; P = 0.072). Conclusion: Worse baseline health, worse breathlessness mastery, but not severity, and openness were associated with a better odds of response. Breathlessness services must be easy to access, and patients should be encouraged and supported to attend
Evidence For Temperature Change And Oblique Pulsation From Light Curve Fits Of The Pulsating White Dwarf GD 358
Convective driving, the mechanism originally proposed by Brickhill for pulsating white dwarf stars, has gained general acceptance as the generic linear instability mechanism in DAV and dbV white dwarfs. This physical mechanism naturally leads to a nonlinear formulation, reproducing the observed light curves of many pulsating white dwarfs. This numerical model can also provide information on the average depth of a star's convection zone and the inclination angle of its pulsation axis. In this paper, we give two sets of results of nonlinear light curve fits to data on the dbV GD 358. Our first fit is based on data gathered in 2006 by the Whole Earth Telescope; this data set was multiperiodic containing at least 12 individual modes. Our second fit utilizes data obtained in 1996, when GD 358 underwent a dramatic change in excited frequencies accompanied by a rapid increase in fractional amplitude; during this event it was essentially monoperiodic. We argue that GD 358's convection zone was much thinner in 1996 than in 2006, and we interpret this as a result of a short-lived increase in its surface temperature. In addition, we find strong evidence of oblique pulsation using two sets of evenly split triplets in the 2006 data. This marks the first time that oblique pulsation has been identified in a variable white dwarf star.Delaware Asteroseismic Research CenterNational Science Foundation AST-0909107, AST-0607840Norman Hackerman Advanced Research Program 003658-0255-2007Crystal Trust FoundationMt. Cuba ObservatoryUniversity of DelawareAstronom
Continuous macroscopic limit of a discrete stochastic model for interaction of living cells
In the development of multiscale biological models it is crucial to establish
a connection between discrete microscopic or mesoscopic stochastic models and
macroscopic continuous descriptions based on cellular density. In this paper a
continuous limit of a two-dimensional Cellular Potts Model (CPM) with excluded
volume is derived, describing cells moving in a medium and reacting to each
other through both direct contact and long range chemotaxis. The continuous
macroscopic model is obtained as a Fokker-Planck equation describing evolution
of the cell probability density function. All coefficients of the general
macroscopic model are derived from parameters of the CPM and a very good
agreement is demonstrated between CPM Monte Carlo simulations and numerical
solution of the macroscopic model. It is also shown that in the absence of
contact cell-cell interactions, the obtained model reduces to the classical
macroscopic Keller-Segel model. General multiscale approach is demonstrated by
simulating spongy bone formation from loosely packed mesenchyme via the
intramembranous route suggesting that self-organizing physical mechanisms can
account for this developmental process.Comment: 4 pages, 3 figure
Physiological Interactions Of Calcium And Vitamin D In Colon
This study aimed to review the literature about possible physiological interactions of calcium and vitamin D in colon. Previous studies have indicated to protective effects of vitamin D and calcium in case of colon cancers. We wanted to check the physiological effects of both of vitamin D and calcium, and either of each of them alone. We suggested effects of metabolism through induction of changes in the levels of various biomarkers that have influences in carcinogenesis including p53, heat shock proteins, iNOS and WT1 gene
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