bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Turbulent Boundary Layer Flow Over 2D Bump Using Highly Resolved Large Eddy Simulation
Authors: Cavar Dalibor , Meyer Knud Erik
Published: November 2011

A large eddy simulation (LES) study of turbulent non-equilibrium boundary layer flow over 2D Bump, at comparatively low Reynolds number Reh=U∞h/ν=1950, was conducted. A well-known LES issue of obtaining and sustaining turbulent flow inside the computational domain at such low Re, is addressed by conducting a precursor calculation of the spatially developing boundary layer flow. Those results were subsequently used as turbulent inflow database for the main non-equilibrium boundary layer flow computation. The Sagaut (Rech. Aero., pp. 51–63, 1996) sub grid scale (SGS) turbulence model, based on a local estimate of the subgrid scale turbulent kinetic energy ksgs and implicit damping of turbulent SGS viscosity νt(sgs) in the near-wall region, was selected as a suitable basis for the present LES computations due to the fact that block structured MPI parallelized CFD code used in the current computations did not provide a direct possibility for wall-damping of, e.g., the Smagorinsky constant in the near-wall region. The grid utilized in the main calculation consisted of approximately 9.4 × 106 grid points and the boundary layer flow results obtained, regarding both mean flow profiles and turbulence quantities, showed a good agreement with the available laser Doppler anemometry (LDA) measurements. Analysis of the flow was directly able to identify and confirm the existence of internal layers at positions related to the vicinity of the upstream and downstream discontinuities in the surface curvature and also partially confirm a close interdependency between generation and evolution of internal layers and the abrupt changes in the skin friction, previously reported in the literature.
Clostridium difficile Mixed Infection and Reinfection
Authors: Eyre David W. , Walker A. Sarah , Griffiths David , Wilcox Mark H. , Wyllie David H. , Dingle Kate E. , Crook Derrick W. , Peto Tim E. A.
Published: November 2011

Isolates from consecutiveClostridium difficileinfection (CDI) fecal samples underwent multilocus sequence typing. Potential reinfections with different genotypes were identified in 88/560 (16%) sample pairs taken 1 to 1,414 days (median, 24; interquartile range [IQR], 1 to 52 days) apart; odds of reinfection increased by 58% for every doubling of time between samples. Of 109 sample pairs taken on the same day, 3 (3%) had different genotypes. Considering samples 0 to 7 days apart as the same CDI, 7% of cases had mixed infections with >1 genotype.
Comparison of the cobas Human Papillomavirus (HPV) Test with the Hybrid Capture 2 and Linear Array HPV DNA Tests
Authors: Gage Julia C. , Sadorra Mark , LaMere Brandon J. , Kail Randi , Aldrich Carrie , Kinney Walter , Fetterman Barbara , Lorey Thomas , Schiffman Mark , Castle Philip E. ,   for the PaP Cohort Study Group
Published: November 2011

The cobas human papillomavirus (HPV) test (cobas) was recently approved by the U.S. Food and Drug Administration (FDA) and identifies HPV16 and HPV18 separately as well as detecting a pool of 11 HR-HPV genotypes (HPV31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -68) and also HPV66. We compared cobas, Linear Array (LA), and Hybrid Capture 2 (HC2) assays for detection of carcinogenic HPV DNA, and cobas and LA for detection of HPV16 and HPV18 DNA, among the first 1,852 women enrolled in the HPV Persistence and Progression Cohort (PaP Cohort) study. Specimens were tested by all 3 assays 1 year after an HC2-positive result. In 1,824 specimens with cobas results, cobas had an 85.9% agreement with HC2 and 91.0% agreement with LA for carcinogenic HPV detection. When results between cobas and HC2 disagreed, cobas tended to call more women HPV positive (
P
< 0.01). Categorizing cobas and LA results hierarchically according to cancer risk (HPV16, HPV18, other carcinogenic HPV genotypes, or carcinogen negative), there was a 90% agreement for all categories of HPV (
n
= 1,824). We found good agreement between the two U.S. FDA-approved HPV tests, with discrepancies between the two assays due to specific characteristics of the individual assays. Additional studies are needed to compare HC2 and cobas for detecting and predicting CIN3 to understand the clinical implications of the discrepant test results between the two tests.
SEMI-CLASSICAL WAVE PACKET DYNAMICS FOR HARTREE EQUATIONS
Authors: CAO PEI , CARLES RÉMI
Published: November 2011

We study the propagation of wave packets for nonlinear nonlocal Schrödinger equations in the semi-classical limit. When the kernel is smooth, we construct approximate solutions for the wave functions in subcritical, critical and supercritical cases (in terms of the size of the initial data). The validity of the approximation is proved up to Ehrenfest time. For homogeneous kernels, we establish similar results in subcritical and critical cases. Nonlinear superposition principle for two nonlinear wave packets is also considered.
FERMIONIC FIELDS IN THE FUNCTIONAL APPROACH TO CLASSICAL FIELD THEORY
Authors: REJZNER KATARZYNA
Published: November 2011

In this paper, we present a formulation of the classical theory of fermionic (anticommuting) fields, which fits into the general framework proposed by Brunetti, Dütsch and Fredenhagen. It was inspired by the recent developments in perturbative algebraic quantum field theory and it also allows for a deeper structural understanding on the classical level. We propose a modification of this formalism that also allows to treat fermionic fields. In contrast to other formulations of classical theory of anticommuting variables, we do not introduce additional Grassman degrees of freedom. Instead the anticommutativity is introduced in a natural way on the level of functionals. Moreover, our construction incorporates the functional-analytic and topological aspects, which is usually neglected in the treatments of anticommuting fields. We also give an example of an interacting model where our framework can be applied.
ON THE CREATION OF SCALAR PARTICLES IN A FLAT ROBERTSON–WALKER SPACETIME
Authors: HAOUAT S. , CHEKIREB R.
Published: November 2011

The problem of particle creation from vacuum in a flat Robertson–Walker spacetime is studied. Two sets of exact solutions for the Klein–Gordon equation are given when the scale factor is a2(η) = a+b tanh(λη)+c tanh2 (λη). Then the canonical method based on Bogoliubov transformation is applied to calculate the pair creation probability and the density number of created particles. Some particular cosmological models such as radiation dominated universe and Milne universe are discussed. For both cases the vacuum to vacuum transition probability is calculated and the imaginary part of the effective action is extracted.
THE PROTON FORM FACTOR RATIO AT LOW Q2: NEW RESULTS FROM JEFFERSON LAB
Authors: RON G.
Published: November 2011

Recently an experiment at Jefferson Lab has measured the proton form factor ratio, [Formula: see text], down to Q2 ~ 0.3 GeV 2 with unprecedented precision. Based on the results from this experiment, a re-analysis was carried out for the world data on proton form factors, and a new result was extracted for the proton charge radius. The new result is consistent with published CODATA results and is at odds with the new muonic hydrogen measurement at PSI.

We present the results of the new measurement, as well as discuss an upcoming experiment to measure the form factor ratio down to even lower Q2.
EXISTENCE AND EQUILIBRATION OF GLOBAL WEAK SOLUTIONS TO KINETIC MODELS FOR DILUTE POLYMERS II: HOOKEAN-TYPE MODELS
Authors: BARRETT JOHN W. , SÜLI ENDRE
Published: November 2011

We show the existence of global-in-time weak solutions to a general class of coupled Hookean-type bead-spring chain models that arise from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The class of models involves the unsteady incompressible Navier–Stokes equations in a bounded domain in ℝd, d = 2 or 3, for the velocity and the pressure of the fluid, with an elastic extra-stress tensor appearing on the right-hand side in the momentum equation. The extra-stress tensor stems from the random movement of the polymer chains and is defined by the Kramers expression through the associated probability density function that satisfies a Fokker–Planck-type parabolic equation, a crucial feature of which is the presence of a center-of-mass diffusion term. We require no structural assumptions on the drag term in the Fokker–Planck equation; in particular, the drag term need not be corotational. With a square-integrable and divergence-free initial velocity datum ṵ0 for the Navier–Stokes equation and a non-negative initial probability density function ψ0 for the Fokker–Planck equation, which has finite relative entropy with respect to the Maxwellian M, we prove, via a limiting procedure on certain regularization parameters, the existence of a global-in-time weak solution t ↦ (ṵ(t), ψ(t)) to the coupled Navier–Stokes–Fokker–Planck system, satisfying the initial condition (ṵ(0), ψ(0)) = (ṵ0, ψ0), such that t ↦ ṵ(t) belongs to the classical Leray space and t ↦ ψ(t) has bounded relative entropy with respect to M and t ↦ ψ(t)/M has integrable Fisher information (with respect to the measure [Formula: see text]) over any time interval [0, T], T>0. If the density of body forces [Formula: see text] on the right-hand side of the Navier–Stokes momentum equation vanishes, then a weak solution constructed as above is such that t ↦ (ṵ(t), ψ(t)) decays exponentially in time to [Formula: see text] in the [Formula: see text]-norm, at a rate that is independent of (ṵ0, ψ0) and of the center-of-mass diffusion coefficient. Our arguments rely on new compact embedding theorems in Maxwellian-weighted Sobolev spaces and a new extension of the Kolmogorov–Riesz theorem to Banach-space-valued Sobolev spaces.
FINITE VOLUME METHOD FOR GENERAL MULTIFLUID FLOWS GOVERNED BY THE INTERFACE STOKES PROBLEM
Authors: KRELL STELLA
Published: November 2011

We study the approximation of solutions to the steady Stokes problem with a discontinuous viscosity coefficient (interface Stokes problem) in the 2D "Discrete Duality Finite Volume" (DDFV) framework. In order to take into account the discontinuities of the viscosity and to prevent consistency defect in the scheme, we propose to modify the definition of the numerical fluxes on the edges of the mesh where the discontinuity occurs. We first show how to design our modified scheme, called m-DDFV, and we analyze its well-posedness and its convergence properties. Finally, we provide numerical results which confirm that the m-DDFV scheme significantly improves the convergence rate of the usual DDFV method for Stokes problems.
ANALYSIS OF AN INVERSE PROBLEM ARISING IN PHOTOLITHOGRAPHY
Authors: RONDI LUCA , SANTOSA FADIL
Published: November 2011

We consider the inverse problem of determining an optical mask that produces a desired circuit pattern in photolithography. We set the problem as a shape design problem in which the unknown is a two-dimensional domain. The relationship between the target shape and the unknown is modeled through diffractive optics. We develop a variational formulation that is well-posed and propose an approximation that can be shown to have convergence properties. The approximate problem can serve as a foundation to numerical methods, much like the Ambrosio–Tortorelli's approximation of the Mumford–Shah functional in image processing.
A BAYESIAN HYPOTHESIS TESTING APPROACH FOR FINDING UPPER BOUNDS FOR PROBABILITIES THAT PAIRS OF SOFTWARE COMPONENTS FAIL SIMULTANEOUSLY
Authors: KRISTIANSEN MONICA , WINTHER RUNE , NATVIG BENT
Published: November 2011

Predicting the reliability of software systems based on a component-based approach is inherently difficult, in particular due to failure dependencies between software components. One possible way to assess and include dependency aspects in software reliability models is to find upper bounds for probabilities that software components fail simultaneously and then include these into the reliability models. In earlier research, it has been shown that including partial dependency information may give substantial improvements in predicting the reliability of compound software compared to assuming independence between all software components. Furthermore, it has been shown that including dependencies between pairs of data-parallel components may give predictions close to the system's true reliability. In this paper, a Bayesian hypothesis testing approach for finding upper bounds for probabilities that pairs of software components fail simultaneously is described. This approach consists of two main steps: (1) establishing prior probability distributions for probabilities that pairs of software components fail simultaneously and (2) updating these prior probability distributions by performing statistical testing. In this paper, the focus is on the first step in the Bayesian hypothesis testing approach, and two possible procedures for establishing a prior probability distribution for the probability that a pair of software components fails simultaneously are proposed.
In situ methods for assessing alveolar mechanics
Authors: Wu You , Perlman Carrie E.
Published: November 2011

Lung mechanics are an important determinant of physiological and pathophysiological lung function. Recent light microscopy studies of the intact lung have furthered the understanding of lung mechanics but used methodologies that may have introduced artifacts. To address this concern, we employed a short working distance water immersion objective to capture confocal images of a fluorescently labeled alveolar field on the costal surface of the isolated, perfused rat lung. Surface tension held a saline drop between the objective tip and the lung surface, such that the lung surface was unconstrained. For comparison, we also imaged with O-ring and coverslip; with O-ring, coverslip, and vacuum pressure; and without perfusion. Under each condition, we ventilated the lung and imaged the same region at the endpoints of ventilation. We found use of a coverslip caused a minimal enlargement of the alveolar field; additional use of vacuum pressure caused no further dimensional change; and absence of perfusion did not affect alveolar field dimension. Inflation-induced expansion was unaltered by methodology. In response to inflation, percent expansion was the same as recorded by all four alternative methods.
The Role of Bipolar Transurethral Vaporization in the Management of Benign Prostatic Hyperplasia
Authors: Nuhoğlu Bariş , Balci Mustafa Bahadir Can , Aydin Memduh , Hazar Ismet , Onuk Özkan , Taş Tuncay , Fikri Onur
Published: November 2011

Objectives: A prospective randomized study was conducted to evaluate the safety and effectiveness of bipolar plasma vaporization with a novel electrode that produces vaporization of the tissue (transurethral vaporization of the prostate, TUVP) immersed in isotonic saline compared to the standard transurethral resection of the prostate (TURP) in the treatment of benign prostatic hyperplasia (BPH). Patients and Methods: From February 2009 to February 2010, 90 patients with BPH were randomized into two groups, and underwent conventional TURP (group 1) or TUVP (group 2) utilizing bipolar plasma vaporization with an innovative electrode (Olympus Winter & Ibe GmbH, Hamburg, Germany). International Prostate Symptom Scores (IPSS), transrectal ultrasonographic findings, maximal urine flow rates (Qmax), and postvoiding residual urine (PVRU) volumes of all cases were evaluated preoperatively and 1 month, 3 months, and 1 year postoperatively. Preoperative and postoperative serum hemoglobin, hematocrit and sodium concentrations of all patients were measured. All patients included in the study were monitored for 1 year. Results: In patients in group 1 (n = 47; mean age: 64.7 ± 7.3 years) TURP was performed. The patients in group 2 (n = 43; mean age: 65.4 ± 8.9 years) underwent bipolar TUVP. Cases in the two study groups matched for demographic characteristics and clinical parameters were assessed. The evaluation of IPSS scores, PVRU, Qmax, and prostatic volumes of the patients 1 month, 3 months, and 1 year postoperatively did not reveal any significant differences between the two groups. In group 2 (TUVP), postoperative catheter indwelling times were significantly shorter, and Na serum concentrations were also markedly lower (p < 0.005). Conclusion: We detected similar effectiveness and morbidity rates in both groups. Bipolar TUVP has advantages such as shorter catheter indwelling times and hospital stays, and fewer bleeding episodes without any risk of transurethral resection syndrome. We believe that TUVP might be an alternative to TURP which is currently the ‘gold standard’ treatment in BPH.
Updated Neuronal Scaling Rules for the Brains of Glires (Rodents/Lagomorphs)
Authors: Herculano-Houzel Suzana , Ribeiro Pedro , Campos Leandro , Valotta da Silva Alexandre , Torres Laila B. , Catania Kenneth C. , Kaas Jon H.
Published: November 2011

Brain size scales as different functions of its number of neurons across mammalian orders such as rodents, primates, and insectivores. In rodents, we have previously shown that, across a sample of 6 species, from mouse to capybara, the cerebral cortex, cerebellum and the remaining brain structures increase in size faster than they gain neurons, with an accompanying decrease in neuronal density in these structures [Herculano-Houzel et al.: Proc Natl Acad Sci USA 2006;103:12138–12143]. Important remaining questions are whether such neuronal scaling rules within an order apply equally to all pertaining species, and whether they extend to closely related taxa. Here, we examine whether 4 other species of Rodentia, as well as the closely related rabbit (Lagomorpha), conform to the scaling rules identified previously for rodents. We report the updated neuronal scaling rules obtained for the average values of each species in a way that is directly comparable to the scaling rules that apply to primates [Gabi et al.: Brain Behav Evol 2010;76:32–44], and examine whether the scaling relationships are affected when phylogenetic relatedness in the dataset is accounted for. We have found that the brains of the spiny rat, squirrel, prairie dog and rabbit conform to the neuronal scaling rules that apply to the previous sample of rodents. The conformity to the previous rules of the new set of species, which includes the rabbit, suggests that the cellular scaling rules we have identified apply to rodents in general, and probably to Glires as a whole (rodents/lagomorphs), with one notable exception: the naked mole-rat brain is apparently an outlier, with only about half of the neurons expected from its brain size in its cerebral cortex and cerebellum.
Application of a Novel Score Test for Genetic Association Incorporating Gene-Gene Interaction Suggests Functionality for Prostate Cancer Susceptibility Regions
Authors: Ciampa Julia , Yeager Meredith , Jacobs Kevin , Thun Michael J. , Gapstur Susan , Albanes Demetrius , Virtamo Jarmo , Weinstein Stephanie J. , Giovannucci Edward , Willett Walter C. , Cancel-Tassin Geraldine , Cussenot Olivier , Valeri Antoine , Hunter David , Hoover Robert , Thomas Gilles , Chanock Stephen , Holmes Chris , Chatterjee Nilanjan
Published: November 2011

Aims: We introduce an innovative multilocus test for disease association. It is an extension of an existing score test that gains power over alternative methods by incorporating a parsimonious one-degree-of-freedom model for interaction. We use our method in applications designed to detect interactions that generate hypotheses about the functionality of prostate cancer (PRCA) susceptibility regions. Methods: Our proposed score test is designed to gain additional power through the use of a retrospective likelihood that exploits an assumption of independence between unlinked loci in the underlying population. Its performance is validated through simulation. The method is used in conditional scans with data from stage II of the Cancer Genetic Markers of Susceptibility PRCA genome-wide association study. Results: Our proposed method increases power to detect susceptibility loci in diverse settings. It identified two high-ranking, biologically interesting interactions: (1) rs748120 of NR2C2 and subregions of 8q24 that contain independent susceptibility loci specific to PRCA and (2) rs4810671 of SULF2 and both JAZF1 and HNF1B that are associated with PRCA and type 2 diabetes. Conclusions: Our score test is a promising multilocus tool for genetic epidemiology. The results of our applications suggest functionality for poorly understood PRCA susceptibility regions. They motivate replication study.
Women with Gestational Diabetes Develop Glucose Intolerance with High Frequency within One Year Postpartum
Authors: Saucedo Renata , Zarate Arturo , Basurto Lourdes , Hernandez Marcelino , Puello Edgardo , Campos Sandra , Moreno Erika
Published: November 2011

Objective: To investigate the incidence of glucose intolerance postpartum in women with gestational diabetes (GDM) and assess body weight, cholesterol and triglyceride concentrations after delivery. Methods: This was a study of an initial cohort of 100 women with GDM who were tested at 6 weeks, 6 months, and 1 year postpartum. Postpartum evaluations were glucose tolerance, weight and cholesterol and triglycerides. Results: Impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) was present in 36.5% of 52 participants who were assessed at 6 weeks postpartum and diabetes in 17.3%; the remaining 48 women failed to return for the 3 evaluations. By 6 months, IFG/IGT was demonstrated in 55.8% and diabetes in 32.7% of the women. At 1 year, 46.2% exhibited IFG/IGT and 48% diabetes. Moreover, the weight was higher in those women who presented IFG/IGT (75.5 ± 15.2 kg, mean ± SD) and diabetes (79.0 ± 16.2 kg) compared with those who had normal glucose tolerance (65.3 ± 14.5 kg; p < 0.05). In addition, triglycerides were higher in mothers with glucose intolerance (181.3 ± 85.9 mg/dl in IFG/IGT and 230.9 ± 90.9 mg/dl in diabetes) than in women with normal glycemia (147.8 ± 11.2 mg/dl; p < 0.05). Conclusion: We demonstrated an increased incidence of women exhibiting glucose intolerance within 1 year postpartum, mainly in those who remained obese.
Relationships Between Recent Intraplaque Hemorrhage and Stroke Risk Factors in Patients With Carotid Stenosis
Authors: Turc Guillaume , Oppenheim Catherine , Naggara Olivier , Eker Omer F. , Calvet David , Lacour Jean-Christophe , Crozier Sophie , Guegan-Massardier Evelyne , Hénon Hilde , Neau Jean-Philippe , Toussaint Jean-François , Mas Jean-Louis , Méder Jean-François , Touzé Emmanuel ,   for the HIRISC study investigators
Published: November 2011

Objective—

Intraplaque hemorrhage (IPH) is an emerging marker of plaque instability. However, little is known about the relationships between IPH and traditional risk factors and whether these relationships differ between symptomatic and asymptomatic disease.

Methods and Results—

Two hundred thirty-four patients with symptomatic (n=114) or asymptomatic (n=120) carotid stenosis underwent high-resolution plaque magnetic resonance imaging. Seventy-five patients had recent IPH (symptomatic, 33%; asymptomatic, 31%). In symptomatic stenosis, recent IPH was independently associated with degree of stenosis (odds ratio [OR]=4.21, 1.61–10.98 for North American Symptomatic Carotid Endarterectomy Trial >35%; OR=2.92, 1.18–7.24 for European Carotid Surgery Trial >60%), qualifying event (OR=4.13; 1.11–15.32 for stroke or hemispheric transient ischemic attack ≥1 hour versus transient ischemic attack <1 hour or ocular symptoms), time from ischemic event (OR=6.65, 1.56–28.35 for ≤2 weeks; OR=2.24, 0.87–5.81 for 2–12 weeks versus >12 weeks;
P
for trend=0.03). In asymptomatic stenosis, IPH was only associated with stenosis severity >70% by ECST (OR=6.65; 1.95–22.73) but not by the NASCET method.

Conclusion—

Our findings support the potential link between recent IPH and risk of ipsilateral stroke in symptomatic disease but also imply that prognostic studies should adjust for known stroke risk factors in multivariate analyses. In asymptomatic stenosis, the potential predictive value of recent IPH is less likely to be confounded by stroke risk factors.
Integration of Repulsive Guidance Cues Generates Avascular Zones That Shape Mammalian Blood Vessels
Authors: Meadows Stryder M. , Fletcher Peter J. , Moran Carlos , Xu Ke , Neufeld Gera , Chauvet Sophie , Mann Fanny , Krieg Paul A. , Cleaver Ondine
Published: November 2011

Rationale:

Positive signals, such as vascular endothelial growth factor, direct endothelial cells (ECs) to specific locations during blood vessel formation. Less is known about repulsive signal contribution to shaping vessels. Recently, “neuronal guidance cues” have been shown to influence EC behavior, particularly in directing sprouting angiogenesis by repelling ECs. However, their role during de novo blood vessel formation remains unexplored.

Objective:

To identify signals that guide and pattern the first mammalian blood vessels.

Methods and Results:

Using genetic mouse models, we show that blood vessels are sculpted through the generation of stereotyped avascular zones by EC-repulsive cues. We demonstrate that Semaphorin3E (Sema3E) is a key factor that shapes the paired dorsal aortae in mouse, as
sema3E
−/−
embryos develop an abnormally branched aortic plexus with a markedly narrowed avascular midline. In vitro cultures and avian grafting experiments show strong repulsion of ECs by Sema3E-expressing cells. We further identify the mouse notochord as a rich source of multiple redundant neuronal guidance cues. Mouse embryos that lack notochords fail to form cohesive aortic vessels because of loss of the avascular midline, yet maintain lateral avascular zones. We demonstrate that lateral avascular zones are directly generated by the lateral plate mesoderm, a critical source of Sema3E.

Conclusions:

These findings demonstrate that Sema3E-generated avascular zones are critical regulators of mammalian cardiovascular patterning and are the first to identify a repulsive role for the lateral plate mesoderm. Integration of multiple, and in some cases redundant, repulsive cues from various tissues is critical to patterning the first embryonic blood vessels.
Low-Molecular-Weight Heparin Versus Aspirin for Acute Ischemic Stroke With Large Artery Occlusive Disease
Authors: Wang Qiao Shu , Chen Christopher , Chen Xiang Yan , Han Jing Hao , Soo Yannie , Leung Thomas W. , Mok Vincent , Wong Ka Sing Lawrence
Published: November 2011

Background and Purpose—

The Fraxiparin in Stroke Study for the treatment of ischemic stroke (FISS-tris) study showed no superiority of low-molecular-weight heparin (LMWH) over aspirin for the primary end point (Barthel Index) in acute ischemic stroke due to large artery occlusive disease. This study aims to evaluate the efficacy of LMWH and aspirin in selected subgroups so as to generate hypotheses for further studies.

Methods—

The FISS-tris study was a multicenter, randomized trial to investigate the efficacy and safety of LMWH (nadroparin calcium 3800 antifactor Xa IU/0.4 mL subcutaneously twice daily) or aspirin (160 mg once daily) for the treatment of patients with acute ischemic stroke and large artery occlusive disease. The primary outcome was the Barthel Index score dichotomized at 85 6 months poststroke. Exploratory subgroup analysis was performed using different levels of baseline characteristics and the distribution of symptomatic arteries.

Results—

Compared with aspirin, LMWH improved outcome among older patients >68 years (
P
=0.043; OR, 1.86; 95% CI, 1.02–3.41) without ongoing antiplatelet treatment on admission (
P
=0.029; OR, 1.85; 95% CI, 1.06–3.21) and with symptomatic posterior circulation arterial disease (
P
=0.001; OR, 5.76; 95% CI, 2.00–16.56).

Conclusions—

Our findings suggest that LMWH may be of benefit in certain subgroups of patients with acute cerebral infarct and large artery occlusive disease. Hence, further investigation of LMWH may be justified in subgroups such as the elderly, nonusers of antiplatelet agents, and patients with posterior circulation stenosis.

Clinical Trial Registration—

URL:
www.strokecenter.org/trials
. Unique identifier: registration no. 493.
Moderate Dietary Restriction Reduces p53-Mediated Neurovascular Damage and Microglia Activation After Hypoxic Ischemia in Neonatal Brain
Authors: Tu Yi-Fang , Lu Pei-Jung , Huang Chao-Ching , Ho Chien-Jung , Chou Ya-Ping
Published: November 2011

Background and Purpose—

Neurovascular damage, including neuronal apoptosis and blood–brain barrier (BBB) damage, and microglia activation account for the hypoxic-ischemia (HI) susceptibility in neonatal brain. The p53 upregulation is involved in apoptosis, endothelial cell damage, and microglia activation. We hypothesized that underweight induced by dietary restriction (DR) protects against HI in rat pups by attenuating p53-mediated neurovascular damage.

Methods—

Male rat pups were grouped as normal litter (NL) size (12 pups/dam), DR (18 pups/dam), and extreme DR (24 pups/dam) from postnatal day 1 and subjected to HI on postnatal day 7. Immunohistochemistry and immunoblotting were used to determine p53, phospho-murine double minute-2, caspases, BBB damage and microglia activation, and immunofluorescence to determine the cellular distribution of p53. Pharmacological approaches were used to regulate p53.

Results—

The NL, DR, and extreme DR pups had similar TUNEL-positive cells and caspases on postnatal day 7 and comparable learning performance at adulthood. After HI, the DR-HI, but not extreme DR-HI, pups had significantly lower p53, higher phospho-murine double minute-2, lower cleaved caspases, less BBB damage and microglia activation, and less brain volume loss than NL-HI pups. In NL-HI pups, p53 expression was located mainly in the neurons, endothelial cells, and microglia. The p53 blockage by pifithrin-α in NL-HI pups decreased apoptosis, BBB damage, and microglia activation, and was neuroprotective. In contrast, upregulating p53 by nutlin-3 in DR-HI pups increased apoptosis, BBB damage, and microglia activation, and worsened brain damage.

Conclusions—

Moderate DR, but not extreme DR, reduces p53-mediated neurovascular damage after HI and confers long-term protection in neonatal brain.
Plasmalemma Permeability and Necrotic Cell Death Phenotypes After Intracerebral Hemorrhage in Mice
Authors: Zhu Xiaoxia , Tao Luyang , Tejima-Mandeville Emiri , Qiu Jianhua , Park Juyeon , Garber Kent , Ericsson Maria , Lo Eng H. , Whalen Michael J.
Published: November 2011

Background and Purpose—

Traumatic and ischemic brain injury induce plasmalemma permeability and necrosis; however, no studies have examined these aspects of cellular injury in intracerebral hemorrhage models.

Methods—

In vivo propidium iodide (PI) and YOYO-1 were used to assess plasmalemma damage after collagenase-induced intracerebral hemorrhage in mice. Ex vivo aspartylglutamylvalylaspartic acid, terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, and electron microscopy were used to assess the relationship between plasmalemma permeability and mode of cell death. Cell types vulnerable to plasmalemma damage were determined by immunohistochemistry.

Results—

Plasmalemma permeability was first detected in the lesion at 1 to 3 hours and peaked at 48 to 72 hours. Neurons and IBA-1-positive cells with morphological features of monocytes were sensitive, whereas resident microglia and astrocytes were resistant to plasmalemma permeability. PI+ cells colocalized with fluorescent-labeled caspase substrates and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling beginning at 3 to 6 hours. At 48 hours, greater than half of injured cells were PI+/aspartylglutamylvalylaspartic acid− or PI+/terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling− suggesting necrosis, and <5% were PI−/terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling+ or PI−/aspartylglutamylvalylaspartic acid+. Electron microscopy confirmed ultrastructural features of necrosis at 24 hours after intracerebral hemorrhage, high mobility group box protein-1 was released from permeable cells, and mice deficient in receptor interacting protein kinase (RIPK) 3, a known necrosis trigger, had 50% less PI+ cells at 24 hours. Permeable cells remained in the brain for at least 24 hours with <10% spontaneous resealing.

Conclusions—

Necrosis contributes to cell demise after intracerebral hemorrhage. Programmed necrosis and plasmalemma damage may represent novel therapeutic targets to prevent cell death or rescue injured cells after intracerebral hemorrhage.
Relative Survival After Transient Ischaemic Attack
Authors: Gattellari Melina , Goumas Chris , Biost Frances Garden M. , Worthington John M.
Published: November 2011

Background and Purpose—

There is a lack of modern-day data quantifying the effect of transient ischemic attack (TIA) on survival, and recent data do not take into account expected survival.

Methods—

Data for 22 157 adults hospitalized with a TIA from July 1, 2000, to June 30, 2007, in New South Wales, Australia, were linked with registered deaths to June 30, 2009. We estimated survival relative to the age- and sex-matched general population up to 9-years after hospitalization for TIA comparing relative risk of excess death between selected subgroups.

Results—

At 1 year, 91.5% of hospitalized patients with TIA survived compared with 95.0% expected survival in the general population. After 5 years, observed survival was 13.2% lower than expected in relative terms. By 9 years, observed survival was 20% lower than expected. Females had higher relative survival than males (relative risk, 0.79; 95% CI, 0.69–0.90;
P
<0.001). Increasing age was associated with an increasing risk of excess death compared with the age-matched population. Prior hospitalization for stroke (relative risk, 2.63; 95% CI, 1.98–3.49) but not TIA (relative risk, 1.42; 95% CI, 0.86–2.35) significantly increased the risk of excess death. Of all risk factors assessed, congestive heart failure, atrial fibrillation, and prior hospitalization for stroke most strongly impacted survival.

Conclusions—

This study is the first to quantify the long-term effect of hospitalized TIA on relative survival according to age, sex, and medical history. TIA reduces survival by 4% in the first year and by 20% within 9 years. TIA has a minimal effect on mortality in patients <50 years but heralds significant reduction in life expectancy in those >65 years.
An Analysis of Multiple Predecessor Rain Events ahead of Tropical Cyclones Ike and Lowell: 10–15 September 2008
Authors: Bosart Lance F. , Cordeira Jason M. , Galarneau Thomas J. , Moore Benjamin J. , Archambault Heather M.
Published: November 2011

An analysis of three predecessor rain events (PREs) that occurred ahead of North Atlantic tropical cyclone (TC) Ike and east Pacific TC Lowell during 10–15 September 2008 is presented. The three PREs produced all-time daily record rainfall at many locations, including Lubbock, Texas (189.5 mm); Wichita, Kansas (262 mm); and Chicago–O’Hare, Illinois (169 mm), on 11–13 September, respectively.

PRE 1 organized over Texas on 10 September with moisture from a stalled frontal boundary and the Bay of Campeche, and matured with moisture from TC Lowell. PRE 2 organized over the Texas Panhandle on 11 September with moisture from the Bay of Campeche, and developed and matured over Kansas and Missouri with moisture from TC Lowell. PRE 3 developed over Texas on 11 September, merged with and absorbed PRE 2 over Kansas and Missouri, and matured as it ingested moisture from TC Ike. All three PREs matured in the equatorward entrance region of an intensifying subtropical jet stream (STJ).

Heavy rainfall with the three PREs occurred along a plume of moist air characterized by high precipitable water values that extended poleward over the central United States near the juxtaposition of the nose of a low-level jet, a region of lower-tropospheric forcing for ascent along a surface baroclinic zone, and the STJ equatorward entrance region. The cumulative upscale effect of persistent deep convection from the three PREs enhanced and “locked in” a favorable upper-tropospheric flow pattern conducive to ridge development over the Ohio Valley and STJ intensification over the central U.S. and Great Lakes region.
A Kaleidoscope of Understanding: Comparing Real with Random Data, Using Binary-Choice Items, to Study Preservice Elementary Teachers’ Knowledge of Climate Change*
Authors: Hayhoe Douglas , Bullock Shawn , Hayhoe Katharine
Published: November 2011

The authors used a 59-item survey to probe the understanding of climate change by 89 Ontario preservice teachers. The study investigated the usefulness of comparing real survey data from closed, binary choice items, with randomly generated data. Climate change was chosen to be the topic because it is a new emphasis in K–12 science curricula. If teachers had answered the survey randomly, according to Monte Carlo simulations, a normal distribution would result, with 56 of the 59 items answered correctly by 40%–60% of the respondents. A bimodal distribution resulted, however, with 34 items answered correctly by more than 60% and 18 items by less than 40%. Apparently, the teachers knew a lot about climate change, but also had many misconceptions, some identified here for the first time. Item discrimination indices and correlation coefficients, however, were the same for the real versus Monte Carlo data, suggesting that preservice teachers’ knowledge was a “kaleidoscope of understanding,” rather than a coherent picture. This may be because their understanding of climate change came primarily from unconnected sources in the media, or because climate change science involves many different fields of study including astronomy, biology, chemistry, ecology, oceanography, and physics. In conclusion, the analysis herein demonstrates the benefit of comparing real and random data for binary-choice item surveys in multidiscipline topics such as climate change. For those interested in climate change education, these results suggest the importance of emphasizing the difference between reliable and unreliable sources of information and giving careful attention to how to draw on concepts from different scientific fields.
Street Centrality and the Location of Economic Activities in Barcelona
Authors: Porta Sergio , Latora Vito , Wang Fahui , Rueda Salvador , Strano Emanuele , Scellato Salvatore , Cardillo Alessio , Belli Eugenio , Càrdenas Francisco , Cormenzana Berta , Latora Laura
Published: November 2011

The paper examines the geography of three street centrality indices and their correlations with various types of economic activities in Barcelona, Spain. The focus is on what type of street centrality (closeness, betweenness and straightness) is more closely associated with which type of economic activity (primary and secondary). Centralities are calculated purely on the street network by using a multiple centrality assessment model, and a kernel density estimation method is applied to both street centralities and economic activities to permit correlation analysis between them. Results indicate that street centralities are correlated with the location of economic activities and that the correlations are higher with secondary than primary activities. The research suggests that, in urban planning, central urban arterials should be conceived as the cores, not the borders, of neighbourhoods.
Governing Farmland Conversion for Urban Development from the Perspective of Transaction Cost Economics
Authors: Tan Rong , Beckmann Volker , Qu Futian , Wu Cifang
Published: November 2011

This paper considers farmland conversion for the purpose of urban development as a series of transactions and discusses the determinants of appropriate governance structures for governing farmland conversion in terms of process efficiency. Towards this end, the paper develops a theoretical framework for analysing the process of farmland conversion based on transaction cost economics. The framework covers transactions, transaction attributes, governance structures and performance with the aim of minimising transaction costs. The paper also demonstrates the usability of the framework by creating a corresponding quantitative model for a case study in China. Furthermore, it identifies factors that influence the transaction costs associated with farmland conversion in China and explains why the related governance structures are chosen.
The Influence of Graphic Display Format on the Interpretations of Quantitative Risk Information among Adults with Lower Education and Literacy
Authors: McCaffery Kirsten J. , Dixon Ann , Hayen Andrew , Jansen Jesse , Smith Sian , Simpson Judy M.
Published: November 2011

Objective

To test optimal graphic risk communication formats for presenting small probabilities using graphics with a denominator of 1000 to adults with lower education and literacy.

Methods

A randomized experimental study, which took place in adult basic education classes in Sydney, Australia. The participants were 120 adults with lower education and literacy. An experimental computer-based manipulation compared 1) pictographs in 2 forms, shaded “blocks” and unshaded “dots”; and 2) bar charts across different orientations (horizontal/vertical) and numerator size (small <100, medium 100–499, large 500–999). Accuracy (size of error) and ease of processing (reaction time) were assessed on a gist task (estimating the larger chance of survival) and a verbatim task (estimating the size of difference). Preferences for different graph types were also assessed.

Results

Accuracy on the gist task was very high across all conditions (>95%) and not tested further. For the verbatim task, optimal graph type depended on the numerator size. For small numerators, pictographs resulted in fewer errors than bar charts (blocks: odds ratio [OR] = 0.047, 95% confidence interval [CI] = 0.023–0.098; dots: OR = 0.049, 95% CI = 0.024–0.099). For medium and large numerators, bar charts were more accurate (e.g., medium dots: OR = 4.29, 95% CI = 2.9–6.35). Pictographs were generally processed faster for small numerators (e.g., blocks: 14.9 seconds v. bars: 16.2 seconds) and bar charts for medium or large numerators (e.g., large blocks: 41.6 seconds v. 26.7 seconds). Vertical formats were processed slightly faster than horizontal graphs with no difference in accuracy. Most participants preferred bar charts (64%); however, there was no relationship with performance.

Conclusions

For adults with low education and literacy, pictographs are likely to be the best format to use when displaying small numerators (<100/1000) and bar charts for larger numerators (>100/1000).
Global environmental change II
Authors: O’Brien Karen
Published: November 2011

This progress report considers the need for developing a critical body of research on deliberate transformation as a response to global environmental change. Although there is a rapidly growing literature on adaptation to environmental change, including both incremental and transformational adaptation, this often focuses on accommodating change, rather than contesting it and creating alternatives. Given increasing calls from scientists and activists for transformative actions to avoid dangerous changes in the earth system, and the likelihood that ‘urgent’ solutions will be imposed by various interests, many new and important questions are emerging about individual and collective capacities to deliberately transform systems and structures in a manner that is both ethical and sustainable. This presents a transformative challenge to global change science itself that calls for new approaches to transdisciplinary research.
Latino Parent Home-based Practices That Bolster Student Academic Persistence
Authors: Mena Jasmine A.
Published: November 2011

Home-based parental involvement practices (i.e., educational encouragement, monitoring, and support) and their impact on students’ academic persistence were investigated with a sample of 137, ninth-grade Latino students in a northeast high school. Structural Equation Modeling results indicate that the relationship between home-based parental involvement activities and students’ intentions to complete the next school year is mediated by students’ school beliefs (i.e., perceptions of school responsiveness, school engagement-trouble, academic attitudes, and academic self-efficacy). Home-based parental involvement influences children’s attitudes and beliefs about school culminating in students’ intentions to persevere academically. This study addresses the common misperception that Latino parents are not involved in their children’s formal education. An important implication of this study is that parents can have an impact on students’ academic persistence even if they are not able to attend school-based activities.
Insights into Holocene vegetation and climate changes at the southeast of the Andes: Nothofagus forest and Patagonian steppe fire records
Authors: Sottile G.D. , Bamonte F.P. , Mancini M.V. , Bianchi M.M.
Published: November 2011

Ecosystem fire regimes are a consequence of interactions among fuels and climate. The reconstruction of past fire regimes is of great importance for studying past climate changes and controls. The aim of this study is to compare two charcoal and pollen records from the Nothofagus forest-grass steppe ecotone (50°S) and the grass steppe (49°S). We compare fire regime responses to local vegetation changes, and inferred variation on climate conditions between 49° and 52°S during the Holocene. Cerro Frías and La Tercera charcoal records seem to be sensitive to centennial and millennial timescales of vegetation and climate variability inferred for southern Patagonia. During the Pleistocene–Holocene transition and during the middle Holocene, forest patchiness provided fuel vertical and horizontal continuity favoring fire activity. In contrast, in steppe environments high cover of shrubs favored grass patchiness, impeding fire spread. Higher pollen richness and variability through time seem to be related to higher vegetation patchiness. Past fire regime variability at the eastern side of the Andes has been closely related to westerly moisture influence between 52° and 48°S. Southern latitudes have been influenced by polar air mass intrusions to the continent during the last 5000 cal. yr BP.
Sesamol attenuates oxidative stress–mediated experimental acute pancreatitis in rats
Authors: Chu P-Y , Srinivasan P , Deng J-F , Liu M-Y
Published: November 2011

Acute pancreatitis is a potentially fatal disease with no known cure. The initial events in acute pancreatitis may occur within the acinar cells. We examined the effect of sesamol on (i) a cerulein-induced pancreatic acinar cancer cell line, AR42J, and (ii) cerulein-induced experimental acute pancreatitis in rats. Sesamol inhibited amylase activity and increased cell survival. It also inhibited medium lipid peroxidation and 8-hydroxydeoxyguanosine in AR42J cells compared with the cerulein-alone groups. In addition, in cerulein-treated rats, sesamol inhibited serum amylase and lipase levels, pancreatic edema, and lipid peroxidation, but it increased pancreatic glutathione and nitric oxide levels. Thus, we hypothesize that sesamol attenuates cerulein-induced experimental acute pancreatitis by inhibiting the pancreatic acinar cell death associated with oxidative stress in rats.