4,187 research outputs found
Elastic response of filamentous networks with compliant crosslinks
Experiments have shown that elasticity of disordered filamentous networks
with compliant crosslinks is very different from networks with rigid
crosslinks. Here, we model and analyze filamentous networks as a collection of
randomly oriented rigid filaments connected to each other by flexible
crosslinks that are modeled as worm-like chains. For relatively large
extensions we allow for enthalpic stretching of crosslinks' backbones. We show
that for sufficiently high crosslink density, the network linear elastic
response is affine on the scale of the filaments' length. The nonlinear regime
can become highly nonaffine and is characterized by a divergence of the elastic
modulus at finite strain. In contrast to the prior predictions, we do not find
an asymptotic regime in which the differential elastic modulus scales linearly
with the stress, although an approximate linear dependence can be seen in a
transition from entropic to enthalpic regimes. We discuss our results in light
of the recent experiments.Comment: 10 pages, 11 figure
Efficient HTTP based I/O on very large datasets for high performance computing with the libdavix library
Remote data access for data analysis in high performance computing is
commonly done with specialized data access protocols and storage systems. These
protocols are highly optimized for high throughput on very large datasets,
multi-streams, high availability, low latency and efficient parallel I/O. The
purpose of this paper is to describe how we have adapted a generic protocol,
the Hyper Text Transport Protocol (HTTP) to make it a competitive alternative
for high performance I/O and data analysis applications in a global computing
grid: the Worldwide LHC Computing Grid. In this work, we first analyze the
design differences between the HTTP protocol and the most common high
performance I/O protocols, pointing out the main performance weaknesses of
HTTP. Then, we describe in detail how we solved these issues. Our solutions
have been implemented in a toolkit called davix, available through several
recent Linux distributions. Finally, we describe the results of our benchmarks
where we compare the performance of davix against a HPC specific protocol for a
data analysis use case.Comment: Presented at: Very large Data Bases (VLDB) 2014, Hangzho
Quantum key distribution using non-classical photon number correlations in macroscopic light pulses
We propose a new scheme for quantum key distribution using macroscopic
non-classical pulses of light having of the order 10^6 photons per pulse.
Sub-shot-noise quantum correlation between the two polarization modes in a
pulse gives the necessary sensitivity to eavesdropping that ensures the
security of the protocol. We consider pulses of two-mode squeezed light
generated by a type-II seeded parametric amplification process. We analyze the
security of the system in terms of the effect of an eavesdropper on the bit
error rates for the legitimate parties in the key distribution system. We also
consider the effects of imperfect detectors and lossy channels on the security
of the scheme.Comment: Modifications:added new eavesdropping attack, added more references
Submitted to Physical Review A [email protected]
The relation between VLDL-cholesterol and risk of cardiovascular events in patients with manifest cardiovascular disease
INTRODUCTION: Apolipoprotein B containing lipoproteins are atherogenic. There is evidence that with low plasma low density lipoprotein cholesterol (LDL-C) levels residual vascular risk might be caused by triglyceride rich lipoproteins such as very-low density lipoproteins (VLDL), chylomicrons and their remnants. We investigated the relationship between VLDL-cholesterol (VLDL-C) and recurrent major adverse cardiovascular events (MACE), major adverse limb events (MALE) and all-cause mortality in a cohort of patients with cardiovascular disease. METHODS: Prospective cohort study in 8057 patients with cardiovascular disease from the UCC-SMART study. The relation between calculated VLDL-C levels and the occurrence of MACE, MALE and all-cause mortality was analyzed with Cox regression models. RESULTS: Patients mean age was 60 ± 10 years, 74% were male, 4894 (61%) had coronary artery disease, 2445 (30%) stroke, 1425 (18%) peripheral arterial disease and 684 (8%) patients had an abdominal aorta aneurysm at baseline. A total of 1535 MACE, 571 MALE and 1792 deaths were observed during a median follow up of 8.2 years (interquartile range 4.512.2). VLDL-C was not associated with risk of MACE or all-cause mortality. In the highest quartile of VLDL-C the risk was higher for major adverse limb events (MALE) (HR 1.49; 95%CI 1.16-1.93) compared to the lowest quartile, after adjustment for confounders including LDL-C and lipid lowering medication. CONCLUSION: In patients with clinically manifest cardiovascular disease plasma VLDL-C confers an increased risk for MALE, but not for MACE and all-cause mortality, independent of established risk factors including LDL-C and lipid-lowering medication
Structured diabetes self-management education and its association with perceived diabetes knowledge, information, and disease distress: Results of a nationwide population-based study
Objective:
To evaluate, how participation in structured diabetes self-management education (DSME) programs is associated with perceived level of knowledge about diabetes, information needs, information sources and disease distress.
Methods:
We included 796 ever- and 277 never-DSME participants of the population-based survey “Disease knowledge and information needs - Diabetes mellitus (2017)” from Germany. Data on perceived level of diabetes knowledge (12 items), information needs (11 items), information sources (13 items) and disease distress (2 indices) were collected. Multiple logistic regression analyses were used to examine the association of DSME-participation with these outcomes.
Results:
DSME-participants showed a higher level of diabetes knowledge compared to never-DSME participants, particularly in aspects concerning diabetes in general (odds ratio 2.53; 95% confidence intervals 1.48–4.33), treatment (2.41; 1.36–4.26), acute complications (1.91; 1.07–3.41) and diabetes in everyday life (1.83; 1.04–3.22). DSME-participants showed higher information needs regarding late complications (1.51; 1.04–2.18) and acute complications (1.71; 1.71–2.48) than DSME never participants. DSME-participants more frequently consulted diabetologists (5.54; 3.56–8.60) and diabetes care specialists (5.62; 3.61–8.75) as information sources. DSME participation was not associated with disease distress.
Conclusion:
DSME is a valuable tool for improving individual knowledge about diabetes. However, DSME should focus more on psychosocial aspects to reduce the disease burden
Reduced tubulin tyrosination as an early marker of mercury toxicity in differentiating N2a cells
The aims of this work were to compare the effects of methyl mercury chloride and Thimerosal on neurite/process outgrowth and microtubule proteins in differentiating mouse N2a neuroblastoma and rat C6 glioma cells. Exposure for 4 h to sublethal concentrations of both compounds inhibited neurite outgrowth to a similar extent in both cells lines compared to controls. In the case of N2a cells, this inhibitory effect by both compounds was associated with a fall in the reactivity of western blots of cell extracts with monoclonal antibody T1A2, which recognises C-terminally tyrosinated α-tubulin. By contrast, reactivity with monoclonal antibody B512 (which recognises total α-tubulin) was unaffected at the same time point. These findings suggest that decreased tubulin tyrosination represents a neuron-specific early marker of mercury toxicity associated with impaired neurite outgrowth
Using a Frontline Staff Intervention to Improve Cervical Cancer Screening in a Large Academic Internal Medicine Clinic
BACKGROUND: Cervical cancer is the third most common malignancy affecting women. Screening with Papanicolaou (Pap) tests effectively identifies precancerous lesions and early-stage cervical cancer. While the nationwide rate of cervical cancer screening (CCS) is 84%, our urban general internal medicine (GIM) clinic population had a CCS rate of 70% in 2016.
OBJECTIVE: To improve our clinic\u27s CCS rate to match or exceed the national average within 18 months by identifying barriers and testing solutions.
DESIGN: A quality improvement project led by a multidisciplinary group of healthcare providers.
PARTICIPANTS: Our GIM clinic includes 16 attending physicians, 116 resident physicians, and 20 medical assistants (MAs) with an insured and underserved patient population.
INTERVENTION: Phase 1 lasted 9 months and implemented CCS patient outreach, patient financial incentives, and clinic staff education. Phase 2 lasted 9 months and involved a workflow change in which MAs identified candidates for CCS during patient check-in. Feedback spanned the entire study period.
MAIN MEASURES: Our primary outcome was the number of Pap tests completed per month during the 2 study phases. Our secondary outcome was the clinic population\u27s CCS rate for all eligible clinic patients.
KEY RESULTS: After interventions, the average number of monthly Pap tests increased from 35 to 56 in phase 1 and to 75 in phase 2. Of 385 patients contacted in phase 1, 283 scheduled a Pap test and 115 (41%) completed it. Compared to baseline, both interventions improved cervical cancer screening (phase 1 relative risk, 1.86; 95% CI, 1.64-2.10; P \u3c 0.001; phase 2 relative risk, 2.70; 95% CI, 2.40-3.02; P \u3c 0.001). Our clinic\u27s CCS rate improved from 70% to 75% after the 18-month intervention.
CONCLUSIONS: The rate of CCS increased by 5% after a systematic 2-phase organizational intervention that empowered MAs to remind, identify, and prepare candidates during check-in for CCS
Investigation of the thermal stability of Mg/Co periodic multilayers for EUV applications
We present the results of the characterization of Mg/Co periodic multilayers
and their thermal stability for the EUV range. The annealing study is performed
up to a temperature of 400\degree C. Images obtained by scanning transmission
electron microscopy and electron energy loss spectroscopy clearly show the good
quality of the multilayer structure. The measurements of the EUV reflectivity
around 25 nm (~49 eV) indicate that the reflectivity decreases when the
annealing temperature increases above 300\degreeC. X-ray emission spectroscopy
is performed to determine the chemical state of the Mg atoms within the Mg/Co
multilayer. Nuclear magnetic resonance used to determine the chemical state of
the Co atoms and scanning electron microscopy images of cross sections of the
Mg/Co multilayers reveal changes in the morphology of the stack from an
annealing temperature of 305\degreee;C. This explains the observed reflectivity
loss.Comment: Published in Applied Physics A: Materials Science \& Processing
Published at
http://www.springerlink.com.chimie.gate.inist.fr/content/6v396j6m56771r61/ 21
page
Lifetime determination of excited states in Cd-106
Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps
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