Retirement decisions in the presence of technological change: a theoretical and an empirical approach

The paper underlines the major role of productivity as a determinant of the worker’sretirement expectations. We propose an overlapping generation model with a continuum of heterogeneous ability workers. The labor market is endogenously segmented between worker’s having the required ability level to occupy jobs where the productivity is indexed to the technological state (complex jobs) and the rest of workers who are employed in positions whose productivity will be relatively deteriorated in case of technological change (simple jobs). We show that, for a given state of technology, workers in complex positions have a latter retirement date than those in simple positions. Furthermore, in case of a positive technological change, workers in complex positions delay retirement whereas those in simple jobs advance retirement. These findings are confirmed by our empirical approach, where we find that, after a technological change, workers who benefit from a skill upgrading training program have a higher expected retirement ag

Factors associated with intracerebral hemorrhage after thrombolytic therapy for ischemic stroke pooled analysis of placebo data from the Stroke-Acute Ischemic NXY Treatment (SAINT) I and SAINT II trials

<p><b>Background and Purpose:</b> A number of factors have been associated with postthrombolysis intracerebral hemorrhage, but these have varied across studies.</p> <p><b>Methods:</b> We examined patients with acute ischemic stroke treated with intravenous tissue plasminogen activator within 3 hours of symptom onset who were enrolled in the placebo arms of 2 trials (Stroke-Acute Ischemic NXY Treatment [SAINT] I and II Trials) of a putative neuroprotectant. Early CT changes were graded using the Alberta Stroke Program Early CT Score (ASPECTS). Post–tissue plasminogen activator symptomatic intracerebral hemorrhage was defined as a worsening in National Institutes of Health Stroke Scale of ≥4 points within 36 hours with evidence of hemorrhage on follow-up neuroimaging. Good clinical outcome was defined as a modified Rankin scale of 0 to 2 at 90 days.</p> <p><b>Results:</b> Symptomatic intracerebral hemorrhage occurred in 5.6% of 965 patients treated with tissue plasminogen activator. In multivariable analysis, symptomatic intracerebral hemorrhage was increased with baseline antiplatelet use (single antiplatelet: OR, 2.04, 95% CI, 1.07 to 3.87, P=0.03; double antiplatelet: OR, 9.29, 3.28 to 26.32, P<0.001), higher National Institutes of Health Stroke Scale score (OR, 1.09 per point, 1.03 to 1.15, P=0.002), and CT changes defined by ASPECTS (ASPECTS 8 to 9: OR, 2.26, 0.63 to 8.10, P=0.21; ASPECTS ≤7: OR, 5.63, 1.66 to 19.10, P=0.006). Higher National Institutes of Health Stroke Scale was associated with decreased odds of good clinical outcome (OR, 0.82 per point, 0.79 to 0.85, P<0.001). There was no relationship between baseline antiplatelet use or CT changes and clinical outcome.</p> <p><b>Conclusions:</b> Along with higher National Institutes of Health Stroke Scale and extensive early CT changes, baseline antiplatelet use (particularly double antiplatelet therapy) was associated with an increased risk of post–tissue plasminogen activator symptomatic intracerebral hemorrhage. Of these factors, only National Institutes of Health Stroke Scale was associated with clinical outcome.</p&gt

Randomized clinical trial comparing percutaneous closure of patent foramen ovale (PFO) using the Amplatzer PFO Occluder with medical treatment in patients with cryptogenic embolism (PC-Trial): rationale and design

<p>Abstract</p> <p>Background</p> <p>Several studies have shown an association of cryptogenic stroke and embolism with patent foramen ovale (PFO), but the question how to prevent further events in such patients is unresolved. Options include antithrombotic treatment with warfarin or antiplatelet agents or surgical or endovascular closure of the PFO. The PC-Trial was set up to compare endovascular closure and best medical treatment for prevention of recurrent events.</p> <p>Methods</p> <p>The PC-Trial is a randomized clinical trial comparing the efficacy of percutaneous closure of the PFO using the Amplatzer PFO occluder with best medical treatment in patients with cryptogenic embolism, i.e. mostly cryptogenic stroke. Warfarin for 6 months followed by antiplatelet agents is recommended as medical treatment. Randomization is stratified according to patients age (<45 versus ≥45 years), presence of atrial septal aneurysm (ASA yes or no) and number of embolic events before randomization (one versus more than one event). Primary endpoints are death, nonfatal stroke and peripheral embolism.</p> <p>Discussion</p> <p>patients were randomized in 29 centers of Europe, Canada, and Australia. Randomization started February 2000. Enrollment of 414 patients was completed in February 2009. All patients will be followed-up longitudinally. Follow-up is maintained until the last enrolled patient is beyond 2.5 years of follow-up (expected in 2011).</p> <p>Trial Registration</p> <p>Trial listed in ClinicalTrials.gov as <a href="http://www.clinicaltrials.gov/ct2/show/NCT00166257">NCT00166257</a> and sponsored by AGA Medical, Plymouth, MN, USA</p

A novel brain partition highlights the modular skeleton shared by structure and function

Elucidating the intricate relationship between brain structure and function, both in healthy and pathological conditions, is a key challenge for modern neuroscience. Recent progress in neuroimaging has helped advance our understanding of this important issue, with diffusion images providing information about structural connectivity (SC) and functional magnetic resonance imaging shedding light on resting state functional connectivity (rsFC). Here, we adopt a systems approach, relying on modular hierarchical clustering, to study together SC and rsFC datasets gathered independently from healthy human subjects. Our novel approach allows us to find a common skeleton shared by structure and function from which a new, optimal, brain partition can be extracted. We describe the emerging common structure-function modules (SFMs) in detail and compare them with commonly employed anatomical or functional parcellations. Our results underline the strong correspondence between brain structure and resting-state dynamics as well as the emerging coherent organization of the human brain.Work supported by Ikerbasque: The Basque Foundation for Science, Euskampus at UPV/EHU, Gobierno Vasco (Saiotek SAIO13-PE13BF001) and Junta de Andalucía (P09-FQM-4682) to JMC; Ikerbasque Visiting Professor to SS; Junta de Andalucía (P09-FQM-4682) and Spanish Ministry of Economy and Competitiveness (FIS2013-43201-P) to MAM; the European Union’s Seventh Framework Programme (ICT-FET FP7/2007-2013, FET Young Explorers scheme) under grant agreement n. 284772 BRAIN BOW (www.brainbowproject.eu) and by the Joint Italy—Israel Laboratory on Neuroscience to PB. For results validation (figure S8), data were provided by the Human Connectome Project, WU-Minn Consortium (Principal Investigators: David Van Essen and Kamil Ugurbil; 1U54MH091657) funded by the 16 NIH Institutes and Centers that support the NIH Blueprint for Neuroscience Research; and by the McDonnell Center for Systems Neuroscience at Washington University

Effect of body size on operative risk of carotid endarterectomy.

Many studies have found that women have a higher risk of perioperative stroke or death from carotid endarterectomy. Other vascular surgical procedures have demonstrated that body size and morphology impact on operative risk. We correlated the 30 day operative risk of stroke and death in the European Carotid Surgery Trial (ECST) with height, weight, body surface area (BSA), and body mass index using single variable analyses and multivariable logistic regression. Women were at significantly higher risk of perioperative stroke and death in the ECST. Both height and BSA confounded the effect of sex, implying that the generally smaller size of women may contribute to their increased risk. This finding should be validated in other large datasets

Validation assessment of risk scores to predict postthrombolysis intracerebral haemorrhage

<p><b>Background:</b> Two clinical risk scores, the Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores, have been proposed to predict the risk of intracerebral haemorrhage following thrombolysis in acute ischaemic stroke.</p> <p><b>Aims:</b> To validate Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores as predictors of post-tissue plasminogen activator symptomatic intracerebral haemorrhage and asymptomatic intracerebral haemorrhage in an independent cohort.</p> <p><b>Methods:</b> Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores were calculated for the cohort of tissue plasminogen activator-treated patients enrolled in the placebo arms of the SAINT-I and SAINT-II trials. The absolute risk of symptomatic intracerebral haemorrhage and asymptomatic intracerebral haemorrhage associated with each scoring system was determined. The overall predictive value was assessed using c-statistics.</p> <p><b>Results:</b> Symptomatic intracerebral haemorrhage occurred in 5 center dot 6% of 965 patients treated with tissue plasminogen activator in the SAINT cohorts. The risk of symptomatic intracerebral haemorrhage was modestly greater, with higher Haemorrhage After Thrombolysis scores (0: 4 center dot 1%, 1: 4 center dot 1%, 2: 8 center dot 8%, 3: 12 center dot 5%, 4: 0%, 5: no subjects). Similar results were seen with the Multicentre Stroke Survey score (0: 0%, 1: 4 center dot 8%, 2: 2 center dot 3%, 3: 7 center dot 3%, 4: 6 center dot 3%). In logistic regression, the Haemorrhage After Thrombolysis score was associated with the risk of symptomatic intracerebral haemorrhage (odds ratio=1 center dot 41 per point, 95% confidence interval: 1 center dot 05-1 center dot 89, P=0 center dot 021) and asymptomatic intracerebral haemorrhage (odds ratio=1 center dot 59 per point, 95% confidence interval: 1 center dot 33-1 center dot 92, P &lt; 0 center dot 001). The Multicentre Stroke Survey score was modestly associated with the risk of symptomatic intracerebral haemorrhage (odds ratio=1 center dot 43 per point, 95% confidence interval: 0 center dot 95-2 center dot 15, P=0 center dot 084) and asymptomatic intracerebral haemorrhage (odds ratio=1 center dot 63 per point, 95% confidence interval: 1 center dot 27-2 center dot 08, P &lt; 0 center dot 001). The c-statistic was 0 center dot 59 for predicting symptomatic intracerebral haemorrhage and 0 center dot 61 for asymptomatic intracerebral haemorrhage for both the Haemorrhage After Thrombolysis and the Multicentre Stroke Survey scores.</p> <p><b>Conclusions:</b> While both the Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores were associated with a risk of symptomatic intracerebral haemorrhage, discriminatory ability was limited.</p

Lamellar phases and microemulsions in model ternary blends containing amphiphilic block copolymers

Journal articleConsider a layer consisting of a m3m dielectric crystal, with faces cut parallel to a symmetry plane. Then bond it onto a semi-infinite mm2 piezoelectric substrate. For an X- or Y-cut of the substrate, a Love wave can propagate in the resulting structure and the corresponding dispersion equation is derived analytically. It turns out that when the upper (free) face of the layer is metalized, a fully explicit treatment can also be conducted in the case of a Y-cut rotated about Z. In the case of a germanium layer over a potassium niobate substrate, the wave exists at any wavelength for X- and Y-cuts but this ceases to be the case for rotated cuts, with the appearance of forbidden ranges. By playing on the cut angle, the Love wave can be made to travel faster than, or slower than, or at the same speed as, the shear bulk wave of the layer. A by-product of the analysis is the derivation of the explicit secular equation for the Bleustein-Gulyaev wave in the substrate alone, which corresponds to an asymptotic behavior of the Love wave. The results are valid for other choices for the layer and for the substrate, provided they have the same, or more, symmetries

The crystalline structures of carboxylic acid monolayers adsorbed on graphite

X-ray and neutron diffraction have been used to investigate the formation of solid crystalline monolayers of all of the linear carboxylic acids from C6 to C14 at submonolayer coverage and from C8 to C14 at multilayer coverages, and to characterize their structures. X-rays and neutrons highlight different aspects of the monolayer structures, and their combination is therefore important in structural determination. For all of the acids with an odd number of carbon atoms, the unit cell is rectangular of plane group pgg containing four molecules. The members of the homologous series with an even number of carbon atoms have an oblique unit cell with two molecules per unit cell and plane group p2. This odd−even variation in crystal structure provides an explanation for the odd−even variation observed in monolayer melting points and mixing behavior. In all cases, the molecules are arranged in strongly hydrogen-bonded dimers with their extended axes parallel to the surface and the plane of the carbon skeleton essentially parallel to the graphite surface. The monolayer crystal structures have unit cell dimensions similar to certain close-packed planes of the bulk crystals, but the molecular arrangements are different. There is a 1−3% compression on increasing the coverage over a monolayer