bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Application of the Single-Spiral Inductive-Capacitive Resonant Circuit Sensor for Wireless, Real-Time Characterization of Moisture in Sand
Authors: DeRouin Andrew J. , You Zhanping , Hansen Morgan , Diab Aboelkasim , Ong Keat Ghee
Published: October 2013

A wireless, passive embedded sensor was designed and fabricated for monitoring moisture in sand. The sensor, consisted of an inductive-capacitive (LC) resonant circuit, was made of a printed spiral inductor embedded inside sand. When exposed to an electromagnetic field, the sensor resonated at a specific frequency dependent on the inductance of the inductor and its parasitic capacitance. Since the permittivity of water was much higher than dry sand, moisture in sample increased the parasitic capacitance, thus decreasing the sensor’s resonant frequency. Therefore, the internal moisture level of the sample could be easily measured through tracking the resonant frequency using a detection coil. The fabrication process of this sensor is much simpler compared to LC sensors that contain both capacitive and inductive elements, giving it an economical advantage. A study was conducted to investigate the drying rate of sand samples of different grain sizes. The experimental data showed a strong correlation with the actual moisture content in the samples. The described sensor technology can be applied for long term monitoring of localized water content inside soils and sands to understand the environmental health in these media, or monitoring moisture levels within concrete supports and road pavement.
A Double Diffusive Unsteady MHD Convective Flow Past a Flat Porous Plate Moving through a Binary Mixture with Suction or Injection
Authors: Sastry D. R. V. S. R. K. , Murti A. S. N.
Published: October 2013

The problem of unsteady magnetohydrodynamic convective flow with radiation and chemical reaction past a flat porous plate moving through a binary mixture in an optically thin environment is considered. The governing boundary layer equations are converted to nonlinear ordinary differential equations by similarity transformation and then solved numerically by MATLAB “bvp4c” routine. The velocity, temperature, and concentration profiles are presented graphically for various values of the material parameters. Also a numerical data for the local skin friction coefficient, the local Nusselt number, and local Sherwood number is presented in tabular forms.
The Role of Cell Density and Intratumoral Heterogeneity in Multidrug Resistance
Authors: Lavi Orit , Greene James M. , Levy Doron , Gottesman Michael M.
Published: October 2013

Recent data have demonstrated that cancer drug resistance reflects complex biologic factors, including tumor heterogeneity, varying growth, differentiation, apoptosis pathways, and cell density. As a result, there is a need to find new ways to incorporate these complexities in the mathematical modeling of multidrug resistance. Here, we derive a novel structured population model that describes the behavior of cancer cells under selection with cytotoxic drugs. Our model is designed to estimate intratumoral heterogeneity as a function of the resistance level and time. This updated model of the multidrug resistance problem integrates both genetic and epigenetic changes, density dependence, and intratumoral heterogeneity. Our results suggest that treatment acts as a selection process, whereas genetic/epigenetic alteration rates act as a diffusion process. Application of our model to cancer treatment suggests that reducing alteration rates as a first step in treatment causes a reduction in tumor heterogeneity and may improve targeted therapy. The new insight provided by this model could help to dramatically change the ability of clinical oncologists to design new treatment protocols and analyze the response of patients to therapy. Cancer Res; 73(24); 7168–75. ©2013 AACR.
mTOR Inhibition Specifically Sensitizes Colorectal Cancers with KRAS or BRAF Mutations to BCL-2/BCL-XL Inhibition by Suppressing MCL-1
Authors: Faber Anthony C. , Coffee Erin M. , Costa Carlotta , Dastur Anahita , Ebi Hiromichi , Hata Aaron N. , Yeo Alan T. , Edelman Elena J. , Song Youngchul , Tam Ah Ting , Boisvert Jessica L. , Milano Randy J. , Roper Jatin , Kodack David P. , Jain Rakesh K. , Corcoran Ryan B. , Rivera Miguel N. , Ramaswamy Sridhar , Hung Kenneth E. , Benes Cyril H. , Engelman Jeffrey A.
Published: October 2013

Colorectal cancers harboring KRAS or BRAF mutations are refractory to current targeted therapies. Using data from a high-throughput drug screen, we have developed a novel therapeutic strategy that targets the apoptotic machinery using the BCL-2 family inhibitor ABT-263 (navitoclax) in combination with a TORC1/2 inhibitor, AZD8055. This combination leads to efficient apoptosis specifically in KRAS- and BRAF-mutant but not wild-type (WT) colorectal cancer cells. This specific susceptibility results from TORC1/2 inhibition leading to suppression of MCL-1 expression in mutant, but not WT, colorectal cancers, leading to abrogation of BIM/MCL-1 complexes. This combination strategy leads to tumor regressions in both KRAS-mutant colorectal cancer xenograft and genetically engineered mouse models of colorectal cancer, but not in the corresponding KRAS-WT colorectal cancer models. These data suggest that the combination of BCL-2/BCL-XL inhibitors with TORC1/2 inhibitors constitutes a promising targeted therapy strategy to treat these recalcitrant cancers.

Significance: Effective targeted therapies directed against colorectal cancer with activating mutations in KRAS remain elusive. We have leveraged drug-screen data from a large panel of human colorectal cancers to uncover an effective, rational targeted therapy strategy that has preferential activity in colorectal cancers with KRAS or BRAF mutations. This combination may be developed for clinical testing. Cancer Discov; 4(1); 42–52. ©2013 AACR.

See related commentary by Russo et al., p. 19

This article is highlighted in the In This Issue feature, p. 1
Impact of Local Ablation on Interconnected Channels Within Ventricular Scar
Authors: Tung Roderick , Mathuria Nilesh S. , Nagel Rich , Mandapati Ravi , Buch Eric F. , Bradfield Jason S. , Vaseghi Marmar , Boyle Noel G. , Shivkumar Kalyanam
Published: October 2013

Background—

The extent to which channels within scar are interconnected is not known. The objective of the study was to evaluate the impact of local ablation of late potentials (LPs) on adjacent and remote areas of slow conduction with simultaneous multipolar mapping.

Methods and Results—

Analysis was performed on consecutive patients referred for ablation of scar-mediated ventricular tachycardia with double ventricular access. Ablation was performed targeting the earliest of LPs visualized on the multipolar catheter, and the impact on later LPs was recorded. In 21 patients, a multipolar catheter placed within scar visualized spatially distinct LPs. Among 39 radiofrequency applications, ablation at earlier LPs had an effect on neighboring and remote LPs in 31 (80%), with delay in 8 (21%), partial elimination in 9 (23%), and complete elimination in 14 (36%). The mean distance where an ablation impact was detected was 17.6±14.7 mm (range, 2–50 mm). Among all patients, 9.7±7.8 radiofrequency applications were delivered to homogenize the targeted scar region with a mean number of 23±12 LPs targeted.

Conclusions—

Ablation can eliminate neighboring and remote areas of slow conduction, suggesting that channels within scar are frequently interconnected. This is the first mechanistic demonstration to show that ablation can modify electrical activity in regions of scar outside of the known radius of an radiofrequency lesion. The targeting of relatively earlier LPs can expedite scar homogenization without the need for extensive ablation of all LPs.
Impact of Atrial Fibrillation on Exercise Capacity in Heart Failure With Preserved Ejection Fraction
Authors: Zakeri Rosita , Borlaug Barry A. , McNulty Steven E. , Mohammed Selma F. , Lewis Gregory D. , Semigran Marc J. , Deswal Anita , LeWinter Martin , Hernandez Adrian F. , Braunwald Eugene , Redfield Margaret M.
Published: October 2013

Background—

Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak V
O
2
in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF.

Methods and Results—

RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak V
O
2
was lower in AF, even after adjustment for age, sex, and chronotropic response, and V
E
/V
CO
2
was higher.

Conclusions—

AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00763867.
Derivation and Validation of a Risk Standardization Model for Benchmarking Hospital Performance for Health-Related Quality of Life Outcomes After Acute Myocardial Infarction
Authors: Arnold Suzanne V. , Masoudi Frederick A. , Rumsfeld John S. , Li Yan , Jones Philip G. , Spertus John A.
Published: October 2013

Background—

Before outcomes-based measures of quality can be used to compare and improve care, they must be risk-standardized to account for variations in patient characteristics. Despite the importance of health-related quality of life (HRQL) outcomes among patients with acute myocardial infarction (AMI), no risk-standardized models have been developed.

Methods and Results—

We assessed disease-specific HRQL using the Seattle Angina Questionnaire at baseline and 1 year later in 2693 unselected AMI patients from 24 hospitals enrolled in the Translational Research Investigating Underlying disparities in acute Myocardial infarction Patients’ Health status (TRIUMPH) registry. Using 57 candidate sociodemographic, economic, and clinical variables present on admission, we developed a parsimonious, hierarchical linear regression model to predict HRQL. Eleven variables were independently associated with poor HRQL after AMI, including younger age, previous coronary artery bypass graft surgery, depressive symptoms, and financial difficulties (R
2
=20%). The model demonstrated excellent internal calibration and reasonable calibration in an independent sample of 1890 AMI patients in a separate registry, although the model slightly overpredicted HRQL scores in the higher deciles. Among the 24 TRIUMPH hospitals, 1-year unadjusted HRQL scores ranged from 67–89. After risk-standardization, HRQL score variability narrowed substantially (range=79–83), and the group of hospital performance (bottom 20%/middle 60%/top 20%) changed in 14 of the 24 hospitals (58% reclassification with risk-standardization).

Conclusions—

In this predictive model for HRQL after AMI, we identified risk factors, including economic and psychological characteristics, associated with HRQL outcomes. Adjusting for these factors substantially altered the rankings of hospitals as compared with unadjusted comparisons. Using this model to compare risk-standardized HRQL outcomes across hospitals may identify processes of care that maximize this important patient-centered outcome.
Pathology of Second-Generation Everolimus-Eluting Stents Versus First-Generation Sirolimus- and Paclitaxel-Eluting Stents in Humans
Authors: Otsuka Fumiyuki , Vorpahl Marc , Nakano Masataka , Foerst Jason , Newell John B. , Sakakura Kenichi , Kutys Robert , Ladich Elena , Finn Aloke V. , Kolodgie Frank D. , Virmani Renu
Published: October 2013

Background—

Clinical trials have demonstrated that the second-generation cobalt-chromium everolimus-eluting stent (CoCr-EES) is superior to the first-generation paclitaxel-eluting stent (PES) and is noninferior or superior to the sirolimus-eluting stent (SES) in terms of safety and efficacy. It remains unclear whether vascular responses to CoCr-EES are different from those to SES and PES because the pathology of CoCr-EES has not been described in humans.

Methods and Results—

A total of 204 lesions (SES=73; PES=85; CoCr-EES=46) from 149 autopsy cases with duration of implantation >30 days and ≤3 years were pathologically analyzed, and comparison of vascular responses was corrected for duration of implantation. The observed frequency of late and very late stent thrombosis was less in CoCr-EES (4%) versus SES (21%;
P
=0.029) and PES (26%;
P
=0.008). Neointimal thickness was comparable among the groups, whereas the percentage of uncovered struts was strikingly lower in CoCr-EES (median=2.6%) versus SES (18.0%;
P
<0.0005) and PES (18.7%;
P
<0.0005). CoCr-EES showed a lower inflammation score (with no hypersensitivity) and less fibrin deposition versus SES and PES. The observed frequency of neoatherosclerosis, however, did not differ significantly among the groups (CoCr-EES=29%; SES=35%; PES=19%). CoCr-EES had the least frequency of stent fracture (CoCr-EES=13%; SES=40%; PES=19%;
P
=0.007 for CoCr-EES versus SES), whereas fracture-related restenosis or thrombosis was comparable among the groups (CoCr-EES=6.5%; SES=5.5%; PES=1.2%).

Conclusions—

CoCr-EES demonstrated greater strut coverage with less inflammation, less fibrin deposition, and less late and very late stent thrombosis compared with SES and PES in human autopsy analysis. Nevertheless, the observed frequencies of neoatherosclerosis and fracture-related adverse pathological events were comparable in these devices, indicating that careful long-term follow-up remains important even after CoCr-EES placement.
Vascular Progenitors From Cord Blood–Derived Induced Pluripotent Stem Cells Possess Augmented Capacity for Regenerating Ischemic Retinal Vasculature
Authors: Park Tea Soon , Bhutto Imran , Zimmerlin Ludovic , Huo Jeffrey S. , Nagaria Pratik , Miller Diana , Rufaihah Abdul Jalil , Talbot Connie , Aguilar Jack , Grebe Rhonda , Merges Carol , Reijo-Pera Renee , Feldman Ricardo A. , Rassool Feyruz , Cooke John , Lutty Gerard , Zambidis Elias T.
Published: October 2013

Background—

The generation of vascular progenitors (VPs) from human induced pluripotent stem cells (hiPSCs) has great potential for treating vascular disorders such as ischemic retinopathies. However, long-term in vivo engraftment of hiPSC-derived VPs into the retina has not yet been reported. This goal may be limited by the low differentiation yield, greater senescence, and poor proliferation of hiPSC-derived vascular cells. To evaluate the potential of hiPSCs for treating ischemic retinopathies, we generated VPs from a repertoire of viral-integrated and nonintegrated fibroblast and cord blood (CB)–derived hiPSC lines and tested their capacity for homing and engrafting into murine retina in an ischemia-reperfusion model.

Methods and Results—

VPs from human embryonic stem cells and hiPSCs were generated with an optimized vascular differentiation system. Fluorescence-activated cell sorting purification of human embryoid body cells differentially expressing endothelial/pericytic markers identified a CD31
+
CD146
+
VP population with high vascular potency. Episomal CB-induced pluripotent stem cells (iPSCs) generated these VPs with higher efficiencies than fibroblast-iPSC. Moreover, in contrast to fibroblast-iPSC-VPs, CB-iPSC-VPs maintained expression signatures more comparable to human embryonic stem cell VPs, expressed higher levels of immature vascular markers, demonstrated less culture senescence and sensitivity to DNA damage, and possessed fewer transmitted reprogramming errors. Luciferase transgene-marked VPs from human embryonic stem cells, CB-iPSCs, and fibroblast-iPSCs were injected systemically or directly into the vitreous of retinal ischemia-reperfusion–injured adult nonobese diabetic-severe combined immunodeficient mice. Only human embryonic stem cell– and CB-iPSC–derived VPs reliably homed and engrafted into injured retinal capillaries, with incorporation into damaged vessels for up to 45 days.

Conclusions—

VPs generated from CB-iPSCs possessed augmented capacity to home, integrate into, and repair damaged retinal vasculature.
Electromagnetic Interference With Implantable Cardioverter-Defibrillators at Power Frequency
Authors: Napp Andreas , Joosten Stephan , Stunder Dominik , Knackstedt Christian , Zink Matthias , Bellmann Barbara , Marx Nikolaus , Schauerte Patrick , Silny Jiri
Published: October 2013

Background—

The number of implantable cardioverter-defibrillators (ICDs) for the prevention of sudden cardiac death is continuing to increase. Given the technological complexity of ICDs, it is of critical importance to identify and control possible harmful electromagnetic interferences between various sources of electromagnetic fields and ICDs in daily life and occupational environments.

Methods and Results—

Interference thresholds of 110 ICD patients (1-, 2-, and 3-chamber ICDs) were evaluated in a specifically developed test site. Patients were exposed to single and combined electric and magnetic 50-Hz fields with strengths of up to 30 kV·m
−1
and 2.55 mT. Tests were conducted considering worst-case conditions, including maximum sensitivity of the device or full inspiration. With devices being programmed to nominal sensitivity, ICDs remained unaffected in 91 patients (83%). Five of 110 devices (5%) showed transient loss of accurate right ventricular sensing, whereas 14 of 31 (45%) of the 2- and 3-chamber devices displayed impaired right atrial sensing. No interference was detected in 71 patients (65%) within the tested limits with programming to maximum sensitivity, whereas 20 of 110 subjects (18%) exhibited right ventricular disturbances and 19 of 31 (61%) subjects exhibited right atrial disturbances.

Conclusions—

Extremely low-frequency daily-life electromagnetic fields do not disturb sensing capabilities of ICDs. However, strong 50-Hz electromagnetic fields, present in certain occupational environments, may cause inappropriate sensing, potentially leading to false detection of atrial/ventricular arrhythmic events. When the right atrial/right ventricular interferences are compared, the atrial lead is more susceptible to electromagnetic fields.

Clinical Trial Registration—

URL:
http://clinicaltrials.gov/ct2/show/NCT01626261
. Unique identifier: NCT01626261.
Community Social Capital and Entrepreneurship
Authors: Kwon Seok-Woo , Heflin Colleen , Ruef Martin
Published: October 2013

The literature on social capital and entrepreneurship often explores individual benefits of social capital, such as the role of personal networks in promoting self-employment. In this article, we instead examine social capital’s public good aspects, arguing that the benefits of social trust and organization memberships accrue not just to the individual but to the community at large. We test these arguments using individual data from the 2000 Census that have been merged with two community surveys, the Social Capital Benchmark Survey and the General Social Survey. We find that individuals in communities with high levels of social trust are more likely to be self-employed compared to individuals in communities with lower levels of social trust. Additionally, membership in organizations connected to the larger community is associated with higher levels of self-employment, but membership in isolated organizations that lack connections to the larger community is associated with lower levels of self-employment. Further analysis suggests that the entrepreneurship-enhancing effects of community social capital are stronger for whites, native-born residents, and long-term community members than for minorities, immigrants, and recent entrants.
Effect of Remote Ischemic Preconditioning in the Elderly Patients With Coronary Artery Disease With Diabetes Mellitus Undergoing Elective Drug-Eluting Stent Implantation
Authors: Xu Xiaohan , Zhou Yujie , Luo Shengjie , Zhang Weijun , Zhao Yingxin , Yu Miao , Ma Qian , Gao Fei , Shen Hua , Zhang Jianwei
Published: October 2013

There is conflicting evidence regarding the effectiveness of remote ischemic preconditioning (RIPC) in patients undergoing elective percutaneous coronary intervention (PCI). Therefore, we prospectively enrolled elderly patients with coronary heart disease (CHD) with diabetes mellitus (DM) undergoing elective drug-eluting stent (DES) implantation. They were randomized to receive RIPC within 2 hours before PCI (n = 102) or not (controls, n = 98). Baseline clinical characteristics were similar between the 2 groups. Despite a trend toward decline, the median high-sensitivity cardiac troponin I (hscTnI) level ( P = .256) and the incidence of myocardial infarction (MI) type 4a ( P = .106) in the RIPC group 16 hours after PCI procedure was not significantly different from the control group. The RIPC could attenuate the release of a myocardial biomarker but failed to show a significant effect on hscTnI level or MI type 4a incidence after PCI procedure in elderly patients with CHD having DM undergoing elective DES implantation.
Comparision of Effects of Rosuvastatin Versus Atorvastatin Treatment on Plasma Levels of Asymmetric Dimethylarginine in Patients With Hyperlipidemia Having Coronary Artery Disease
Authors: Kurtoglu Ertugrul , Balta Sevket , Sincer Isa , Altas Yakup , Atas Halil , Yılmaz Mucahid , Korkmaz Hasan , Erdem Kenan , Akturk Erdal , Demirkol Sait , Can Cagdas
Published: October 2013

Elevated plasma levels of asymmetric dimethylarginine (ADMA) are prevalent in patients with hypercholesterolemia and coronary artery disease. A total of 83 patients with hypercholesterolemia and angiographically documented mild coronary artery stenosis were randomized to rosuvastatin treatment (20 mg) or atorvastatin treatment (40 mg) once daily for 6 weeks after a 4-week dietary lead-in phase. Both statins decreased total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride levels effectively. Only rosuvastatin increased high-density lipoprotein cholesterol (HDL-C) levels. Both rosuvastatin and atorvastatin decreased plasma ADMA levels; rosuvastatin had a significantly greater effect. The reduction in ADMA levels were correlated with the reduction in TC and LDL-C levels as well as LDL-C–HDL-C ratio. Treatment with rosuvastatin or atorvastatin in patients with hyperlipidemia with mild coronary artery stenosis may lead to a decrease in ADMA levels, which may contribute to improved endothelial function.
γ-Glutamyl Transferase Activity and the Burden of Coronary Atherosclerosis in Patients With ST-Segment Elevation Myocardial Infarction
Authors: Baktir Ahmet Oguz , Sarli Bahadir , Demirci Erkan , Saglam Hayrettin , Kurtul Serkan , Sahin Omer , Demirbas Melih , Arinc Huseyin
Published: October 2013

The relationship between extent, severity, and complexity of coronary artery disease (CAD) in patients with ST-segment elevation myocardial infarction (STEMI) and serum γ-glutamyl transferase (GGT) activity has not been adequately studied. We evaluated the relationship between GGT activity and the burden of CAD as assessed by SYNTAX score (SXscore) in patients with STEMI. A total of 243 patients (age 67.1 ± 8.6, 77.4% male) with STEMI were divided into 2 groups. Low- and high-SXscore groups were defined as SXscore <22 and ≥22, respectively. Admission GGT activities were similar between low- and high-SXscore groups (32 ± 17 vs 33 ± 18; P = .625), and there was no significant correlation between GGT activity and SXscore. Although there was an association between high SXscore and major adverse cardiovascular events, as expected, our results did not demonstrate any relationship between admission GGT activities and complexity and extent of the coronary lesions in patients with STEMI.
Effect of Atorvastatin on Low-Density Lipoprotein Subpopulations and Comparison Between Indicators of Plasma Atherogenicity
Authors: Kucera Marek , Oravec Stanislav , Hirnerova Eva , Huckova Nada , Celecova Zuzana , Gaspar Ludovit , Banach Maciej
Published: October 2013

Treatment with statins to achieve target low-density lipoprotein cholesterol (LDL-C) levels is still associated with residual risk. Lipoprotein subfraction evaluation can provide additional information regarding atherogenicity in these individuals. Patients (n = 40) with hypercholesterolemia (29 females, mean age 63 years), without previous hypolipemic treatment, were treated with atorvastatin 40 mg/d for 3 months. Atorvastatin significantly reduced total cholesterol (6.7 ± 1.0 vs 4.6 ± 1.3 mmol/L, P < .001), LDL-C (4.3 ± 1.0 vs 2.6 ± 0.9 mmol/L, P < .001), triglycerides (1.8 ± 0.9 vs 1.5 ± 1.00 mmol/L, P < .05), small-dense LDL (sdLDL) fraction 3 to 7 (0.22 ± 0.37 vs 0.09 ± 0.16 mmol/L, P < .001), and apolipoprotein B (apoB; 1.0 ± 0.2 vs 0.74 ± 0.2 g/L, P < .001). There was a negative correlation of atherogenic index of plasma (AIP) with buoyant LDL-1 and LDL-2 ( r = −.35; P < .05) and positive with sdLDL-3 to sdLDL-7 ( r = .52, P < .001). Administration of atorvastatin 40 mg/d in patients with hypercholesterolemia caused a shift in sdLDL subfractions to large, buoyant subfractions. The AIP better correlated with sdLDL than apoB levels.
Serum Bilirubin Level and Aortic Intima–Media Thickness in Patients Without Clinical Manifestation of Atherosclerotic Cardiovascular Disease
Authors: Kalkan Gülhan Yüksel , Gür Mustafa , Baykan Ahmet Oytun , Koyunsever Nermin Yıldız , Kaypaklı Onur , Sen Omer , Kuloğlu Osman , Şeker Taner , Uçar Hakan , Akyol Selehattin , Elbasan Zafer , Şahin Durmuş Yıldıray , Çaylı Murat
Published: October 2013

We investigated the association between serum bilirubin level and thoracic aortic intima–media thickness (IMT). The study population consisted of 417 patients without coronary artery disease, who underwent transesophageal echocardiography examination for various indications. The highest aortic IMT values were observed in the bilirubinlow group compared with the bilirubinhigh group ( P < .001). Serum bilirubin level was associated with high-density lipoprotein cholesterol level ( r = .162, P = .001), high-sensitivity C-reactive protein (hsCRP; r = −.265, P < .001), and aortic IMT ( r = −.551, P < .001) in bivariate analysis. Multivariate linear regression analysis showed that serum bilirubin level was independently and negatively associated with hsCRP (β = −.095, P = .028) and aortic IMT (β = −.513, P < .001). Serum bilirubin level may be an independent predictor of the extent of subclinical aortic atherosclerosis assessed by thoracic aortic IMT.
Serum Concentration of Uric Acid Associated With Prehypertension Among Chinese Population
Authors: Bao Xundi , Wang Qing , Chen Genwang , Wang Qunan , Liang Ren , Zhang Shunli
Published: October 2013

We evaluated the association between serum uric acid (SUA) levels and prehypertension in a Chinese population. A cross-sectional study was performed during 2008 to 2010, and a total of 11199 participants without hypertension or other cardiovascular diseases (CADs), aged ≥35 years, were available for analysis. After adjusting for age, alcohol consumption, smoking status, body mass index, diabetes, total cholesterol, triglycerides, serum creatinine, the odds ratios (ORs) and 95% confidence intervals (CIs) of the prehypertension from the lowest (referent) to the highest levels of SUA were 1.00 (95% CI, 0.91-1.10), 1.12 (95% CI, 1.03-1.21), 1.17 (95% CI, 1.09-1.27), and 1.25 (95% CI, 1.13-1.39; linear trend P = .002). This association persisted in subgroup analysis by gender and was also consistent with separate analysis by classification of age, smoking status, alcohol usage, overweight, and diabetes mellitus. Independent of other cardiovascular risk factors, higher SUA levels are positively associated with prehypertension in a Chinese population without hypertension and CADs. Prospective trials should evaluate interventions that lower the SUA levels.
‘Greatly exaggerated’: the death of EU studies–new regionalism dialogue? A reply to Jørgensen and Valbjørn
Authors: Rosamond Ben , Warleigh-Lack Alex
Published: October 2013

In a recent piece in this journal Jørgensen and Valbjørn develop a typology of intellectual dialogue across fields that yields rather negative conclusions about the prospects for sustainable dialogue between ‘European studies’ and the ‘new regionalism’. This response disputes this pessimistic conclusion. First, it is argued that while their derivation of models of dialogue is impressive, it is nonetheless incomplete. Using Jørgensen and Valbjørn’s premises, the article derives a ‘market’ mode of dialogue that represents a challenge to their assumption that dialogue will tend towards hierarchy. Second, the article accepts that there are important ‘sociology of knowledge’ impediments to effective dialogue within political science and International Relations, but maintains that Jørgensen and Valbjørn fail to work through the question of ‘dialogue between whom?’ The article argues that methodological division is the most significant impediment to dialogue, but maintains that within-methodology dialogue is more than viable in the case under scrutiny in this debate. Third, having established these general parameters of disagreement, the article moves to a number of more particular criticisms of the assumptions made by Jørgensen and Valbjørn about extant calls for dialogue between scholars in these two fields.
A Bridge Too Far? Challenges in Evaluating Principal Effectiveness
Authors: Fuller Edward J. , Hollingworth Liz
Published: October 2013

Purpose: The purpose of this article is to examine the assumptions underlying efforts to evaluate principal effectiveness in terms of student test scores, to review extant research on efforts to estimate principal effectiveness, and to discuss the appropriateness of including estimates of principal effectiveness in evaluations of principals. Method: We review 10 different strategies for estimating principal effectiveness based on student test scores, representing all of the strategies currently employed by states and districts. We base our reviews on the literature in three areas: use of test scores, evaluation, and statistical approaches to estimating the effects of individuals and schools on student test scores. Conclusions: We conclude there are currently no strategies to estimate principal effectiveness that accurately capture the independent effect of principals on student test scores; thus, these current strategies send inaccurate signals to both principals and those who make employment decisions about principals. Moreover, we also conclude a substantial proportion of principals could not be included in the most accurate strategies to assess principal effectiveness. Implications: This research has profound implications for states and districts implementing principal evaluation systems, particularly those making high-stakes decisions about principals based on statistical estimates of principal effectiveness. Indeed, such statistical estimates should be used not for making judgments or decisions about principals but rather as a screening tool to identify where states and districts should focus more in-depth and accurate strategies to evaluate principal effectiveness.
Estimating the Nominal Response Model Under Nonnormal Conditions
Authors: Preston Kathleen Suzanne Johnson , Reise Steven Paul
Published: October 2013

The nominal response model (NRM), a much understudied polytomous item response theory (IRT) model, provides researchers the unique opportunity to evaluate within-item category distinctions. Polytomous IRT models, such as the NRM, are frequently applied to psychological assessments representing constructs that are unlikely to be normally distributed in the population. Unfortunately, models estimated using estimation software with the MML/EM algorithm frequently employs a set of normal quadrature points, effectively ignoring the true shape of the latent trait distribution. To address this problem, the current research implements an alternative estimation approach, Ramsay Curve Item Response Theory (RC-IRT), to provide more accurate item parameter estimates modeled under the NRM under normal, skewed, and bimodal latent trait distributions for ordered polytomous items. Based on the results of improved item parameter recovery under RC-IRT, it is recommended that RC-IRT estimation be implemented whenever a researcher considers the construct being measured has the potential of being nonnormally distributed.
Measuring Instructional Differentiation in a Large-Scale Experiment
Authors: Williams Ryan T. , Swanlund Andrew , Miller Shazia , Konstantopoulos Spyros , Eno Jared , van der Ploeg Arie , Meyers Coby
Published: October 2013

This study operationalizes four measures of instructional differentiation: one for Grade 2 English language arts (ELA), one for Grade 2 mathematics, one for Grade 5 ELA, and one for Grade 5 mathematics. Our study evaluates their measurement properties of each measure in a large field experiment: the Indiana Diagnostic Assessment Tools Study, which included two consecutive cluster randomized trials (CRTs) of the effects of interim assessments on student achievement. Each log was designed to measure instructional practices as they were implemented for eight randomly selected students in the participating teachers’ classrooms. A total of 592 teachers from 127 schools took part in this study. Logs were administered 16 times in each experiment. Item responses to the logs were scaled using the Rasch model and reliability estimates for the differentiation measures were evaluated at the log level (observations within teachers), the teacher level, and the school level. Estimated reliability was above .70 for each of the log- and teacher-level measures. At the school level, reliability estimates were lower for Grade 5 ELA and mathematics. The variance between teachers and schools on the scaled differentiation measures was substantially less than within-teacher variation. These results provide preliminary evidence that teacher instructional logs may provide useful measures of instructional differentiation in elementary grades at multiple levels of aggregation.
Alternative Smoothing and Scaling Strategies for Weighted Composite Scores
Authors: Moses Tim
Published: October 2013

In this study, smoothing and scaling approaches are compared for estimating subscore-to-composite scaling results involving composites computed as rounded and weighted combinations of subscores. The considered smoothing and scaling approaches included those based on raw data, on smoothing the bivariate distribution of the subscores, on smoothing the bivariate distribution of the subscore and weighted composite, and two weighted averages of the raw and smoothed marginal distributions. Results from simulations showed that the approaches differed in terms of their estimation accuracy for scaling situations with smaller and larger sample sizes, and on weighted composite distributions of varied complexity.
A Coincidence Analysis of a Causal Chain
Authors: Baumgartner Michael , Epple Ruedi
Published: October 2013

This article applies coincidence analysis ( CNA), a Boolean method of causal analysis presented in Baumgartner (2009a), to configurational data on the Swiss minaret vote of 2009. CNA is related to qualitative comparative analysis (QCA) (Ragin 2008), but contrary to the latter does not minimize sufficient and necessary conditions by means of Quine–McCluskey optimization, but based on its own custom built optimization algorithm. The latter greatly facilitates the analysis of data featuring chain-like causal dependencies among the conditions of an ultimate outcome—as can be found in the data on the Swiss minaret vote. Apart from providing a model of the causal structure behind the Swiss minaret vote, we show that a CNA of that data is preferable over a QCA.
Agent-Based Models in Empirical Social Research
Authors: Bruch Elizabeth , Atwell Jon
Published: October 2013

Agent-based modeling has become increasingly popular in recent years, but there is still no codified set of recommendations or practices for how to use these models within a program of empirical research. This article provides ideas and practical guidelines drawn from sociology, biology, computer science, epidemiology, and statistics. We first discuss the motivations for using agent-based models in both basic science and policy-oriented social research. Next, we provide an overview of methods and strategies for incorporating data on behavior and populations into agent-based models, and review techniques for validating and testing the sensitivity of agent-based models. We close with suggested directions for future research.
Barriers to caregiver involvement in a child safety intervention in South Africa
Authors: van Niekerk Ashley , Ismail Ghouwa
Published: October 2013

Injuries are a global threat to children’s health and are disproportionately prevalent in Sub-Saharan Africa. Despite the rates of childhood injuries, research into prevention and the community and family conditions required for such interventions have been largely under-researched. This article reviews international work highlighting caregiver involvement in the implementation of interventions in a number of sectors, including the health, education, and safety domains. This work, based largely on experiences in high-income countries, indicates that there are considerable challenges inhibiting caregiver involvement in such interventions. This article explores caregiver understandings of the personal, familial, and contextual barriers to their participation in child safety initiatives. It highlights the obstacles to involvement in a community-centred child safety promotion intervention that was implemented in a low-income setting in the Western Cape. A narrative approach was employed with study data captured in individual interviews and analysed using guidelines for conducting narrative analysis. In total, 11 caregivers were interviewed. Caregiver understandings of the impediments to greater involvement in safety interventions included the multifaceted nature of their personal and social difficulties. These included the prioritisation of work opportunities; conflict and estrangement from partners, family, and the community; and adverse living conditions. In such situations, many reported constrained personal choices and disengagement from many aspects of community relationships. Despite this stance, caregivers recognised the community connectedness, belonging, and responsibility needed to achieve a safer and healthier community.
Towards relationality: interposing the dichotomy between peace and violence
Authors: Lau Ursula , Seedat Mohamed
Published: October 2013

Some international peace organisations and associated globalised instruments, such as the World Peace Index and Global Peace Index, construct peace and violence in antithetical terms. These instruments, underpinned by hegemonic norms and a project management rationale, position peace as a marker of liberal democracies and violence as a characteristic of weak, nondemocratic states. We argue for a mutuality of peace and violence, as constituted in institutionalised and everyday practices of belonging and as having affective and relational dimensions. Drawing on psychosocial feminist ideas, we propose a ‘conceptual intervention’ that interposes the peace–violence binary and, in so doing, privileges locally grounded meanings and experiences of peace and violence. We explore two ‘parallel’ dimensions of engagement: storytelling and process. Storytelling and story-listening is an avenue to recognise the Other, and process entails collective reflexivity, mutual learning, and engagement where the balance between recognition and differentiation is navigated and negotiated. On both dimensions, the focus is on fostering psychological processes that promote mutual recognition, honouring processes of uncertainty, and mobilising (rather than silencing) ambivalence as wellsprings for creative action.
Use of ground EPDM wastes in EPDM-based rubber compounds
Authors: Karaağaç Bağdagül , Turan H Oğuzhan , Oral Demet Dengiz
Published: October 2013

Ethylene-propylene-diene monomer rubber (EPDM)-based ground wastes (W-EPDM) are reutilized as rubber matrix in plug material compounds for automotive applications. Production scraps of target product are ground to 35, 40 and 60 mesh in ambient conditions. Effect of particle size and the amount of W-EPDM is studied. A new trial product of maleated ethylene-propylene rubber (EPM) and bitumen are used to improve interphase adhesion of the waste and the virgin EPDM. Cure characteristics, physico-mechanical and aging properties of all compounds are determined. Micro structure of the vulcanizates is studied for explaining dispersion and interaction between different phases. Reutilization of W-EPDM causes some reasonable deterioration in cure characteristics and mechanical properties of the product. However, some systematic and alternative recipes for plug materials are suggested considering cost and environmental benefits.
Preparation of anhydridized chlorinated polyvinyl chloride with enhanced properties and investigation of the factors affecting the chain structure of the graft copolymer
Authors: Meng Li , Xu Chao , Jing Zhao , Zhao Jiruo , Feng Ying , Hu Haiqing
Published: October 2013

A graft copolymer, composed of maleic anhydride as side group and chlorinated polyvinyl chloride as backbone, was prepared via in situ chlorinating graft copolymerization. The effect of graft degree of the graft copolymer on the chain structure is discussed through proton nuclear magnetic resonance. The results of differential scanning calorimetry and thermogravimetic analysis showed glass transition temperature of the graft copolymer did not change with increase in graft degree, but thermal stability of the product improved much with increase in graft degree. The results of gel content measurements showed the increasing graft degree was favorable to prevent cross-linking reaction of the product.
Factorial design investigation on two-way quaternary factors of thermal aging of chlorinated nitrile latex tensile properties
Authors: Sin Lee Tin , Ng Lin-Huey , Bee Soo-Tueen , Tee Tiam-Ting , Rahmat Abdul Razak , He Wei
Published: October 2013

This study aims at investigating the quaternary factors, namely zinc di-N-butyl dithiocarbonmate (ZDBC), sulfur, zinc oxide (ZnO), and potassium hydroxide (KOH) on the tensile strength and elongation of chlorinated nitrile latex film. Full factorial design analysis was employed to examine the factors and their combination two-way interactions with the tensile properties. The factors’ effect on the variability or the stability of the resulting latex films were analyzed as well. The results showed that KOH, which was used to adjust the pH of the latex system greatly affected the tensile strength of the latex film, whereas sulfur has minor influence on tensile strength. Meanwhile, KOH also interacted in combination with ZnO and sulfur to affect the elongation of the latex films. Addition of KOH changed the pH by affecting the electronic repulsion and gelling stability of the latex matrix. Consequently, the variability in tensile strength and elongation of latex film were according to the amount of KOH. Finally, the simple mathematical models with a regression range 0.73–0.86 were developed to relate the factors and the tensile properties of the latex.
Rubber composites based on silane-treated stöber silica and nitrile rubber
Authors: Kapgate Bharat P , Das Chayan , Basu Debdipta , Das Amit , Heinrich Gert
Published: October 2013

Role of silane-treated stöber silica as reinforcing filler for nitrile rubber (NBR) has been studied. Stöber silica is synthesized by sol–gel method, and the surface of silica is modified with the treatment of silane-coupling agent viz. γ-mercaptopropyltrimethoxysilane (γ-MPS) in varying proportions. Average particle size of stöber silica of spherical shape in the range of 200 to 400 nm is evident from scanning electron microscopy (SEM). Surface modification of silica particle with silane-coupling agents decreases surface energy and reduces agglomeration of silica particles in rubber matrix. Stress–strain study and dynamic mechanical analysis of silica-filled composites are compared with the unfilled ones. Analysis of cross-linking density, mechanical properties, and storage moduli indicates a strong rubber–filler interaction in the silane-treated, silica-filled NBR composites. Silane treatment is found to be effective in uniform dispersion of silica in rubber matrix and in improving the mechanical properties of rubber composite. Different functionalities of organosilane at its both end improve the compatibility of silica with rubber matrix and offer better rubber–filler interaction.
Grafting of glycidyl methacrylate onto isotactic polybutene-1 initiated by di-tert-butyl peroxide
Authors: Zhao Yongxian , Zhou Yanfen , Chen Junyi , Han Lei
Published: October 2013

In this study, isotactic polybutene-1 (iPB) was functionalized with glycidyl methacrylate (GMA) using di-tert-butyl peroxide as an initiator via a radical-initiated melt grafting reaction, while styrene (St) was used as a comonomer to enhance the grafting reaction. The effect of temperature, concentration of initial GMA and peroxide, and the addition of St comonomer on the final grafting degree, grafting efficiency, and the melt flow rate of the grafted polymer were studied. The results indicated that St was an effective comonomer. Moreover, the GMA grafted iPB had higher crystallization temperature and faster crystallization rate compared with the unmodified iPB based on the differential scanning calorimetric tests.
Seasoned Long Enough in Concentration
Authors: Jenks Hillary
Published: October 2013

Communities of color in post–World War II California sought, with varying degrees of success, to participate in the suburban dream of upward mobility. In the process, they reshaped the physical and racial geography of metropolitan Los Angeles, creating places like “the first suburban Chinatown” and “the Mexican Beverly Hills.” In the South Bay, hub of the region’s aerospace economy, Japanese Americans and African Americans purchased homes and became civic leaders in the neighboring suburban cities of Gardena and Compton, respectively. Japanese American realtors and businessmen actively exploited transnational social and kinship networks to attract Japanese corporate capital to Gardena, investment that helped the suburb survive loss of revenue from closing card clubs and aerospace recession in the late 1970s and early 1980s. At the same time, they cooperated with Anglo city and county officials to prevent the disinvestment and negative racialization impacting Compton from extending to Gardena. In their roles as suburban place entrepreneurs, Japanese Americans strategically manipulated the available roles of transnational broker and model minority to attain the full benefits of first-class citizenship tied to suburban homeownership.