bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship Between Structure and Electromigration Characteristics of Pure Aluminum Films
Authors: Field David P. , Kononenko Oleg V. , Matveev Victor N. 
Published: February 2013

ABSTRACTAluminum films were deposited from a high purity aluminum source by the self-ion assisted technique onto oxidized silicon wafers with TiN sub-layers. The ions were accelerated toward the substrate by potentials of 0, 3 and 6 kV. The films were patterned into strips 670 μm long and 8 μm wide using photo-lithographic procedures and wet etching. Average drift velocities were measured in the films tested under electromigration conditions. Electromigration activation energy was obtained for the films. It was found that electromigration activation energy increased with the acceleration potential. The strength of the (111) fiber texture, however, decreased with the acceleration potential. Therefore, the weaker textures resulted in higher electromigration activation energies. These results can be explained in terms of grain boundary structure, which controls electromigration behavior. By using orientation imaging microscopy to characterize the structures, it was shown that the weaker textured specimens contained a high fraction of low angle and low diffusivity grain boundaries.
In-Situ Tem-Investigation of Stress- and Electromigration- Induced Void Formation and Growth in Passivated Al-Interconnects
Authors: Heinen Dirk , Schroeder Herbert 
Published: February 2013

ABSTRACTIn-situ TEM observations on void formation and growth have been performed in passivated Al-lines in order to collect detailed microstructural data such as void number density, void size distribution, and growth rates as a basis for modelling stress relaxation and electromigration (EM) effects.The samples were 0.5mm long lines of 200nm thick Al with different widths (0.8, 1.6 and 2.4μm) passivated with 200μm thick SiNx. Additional experimental parameters were average grain size (0.5μm to more than 3μm, i.e. nearly perfect bamboo structure in the lines), relaxation time (0.1 to 20h) and temperature (20 – 300°C) and electromigration current density (without current up to ∼2MA/cm2).Measurements without current reveal that stress induced voids– develop after a temperature step of 50°C during cooling from 450°C and above. Upon heating from RT they start shrinking at 150°C and disappear completely at 350°C.– decrease in number and total relative volume but have constant mean void size with increasing number n of temperature cycles (n < 4)– show a strong dependence of their total relative volume on the microstructure (grain size, bamboo structure) which is strongly dependent on the anealing temperature for T ≥450° C.– show growth rates during isothermal annealing which are very dependent on relaxation time and temperature.Additional measurement with an applied electrical current, i.e. during an EM-test, show that nearly all the preexisting stress-induced voids– change their shapes and positions. This is dependent on electrical current density and time. Their frequently observed motion along the line (against the electron wind) was not neccessarily stopped by so-called blocking grains, i.e. grains without boundaries parallel to the line.– slightly change their total number but nearly maintain their total relative volume which is independent of current density or time.The collected statistical microstructural data are in good agreement with macroscopic stress relaxation results by wafer curvature and X-ray diffraction and recent in-situ stress measurement during an EM-test.
The Effect of Cu Concentration and Distribution on the Lifetimes of Submicron, Bamboo Al(Cu) Runners
Authors: Theiss Silva K. , Prybyla J. A. , Marcus M. A. 
Published: February 2013

ABSTRACTWe have studied the effect of Cu concentration and initial distribution on the electromigration lifetimes of 0.3 – 0.8 μm wide, ≥ 99% bamboo Al interconnects. The mechanism by which Cu reduces electromigration in polygranular interconnects may not be important in bamboo interconnects, so it is not possible to predict whether Cu will have a positive or negative effect in this case. Samples containing 0.0, 0.5, and 0.9 wt. % Cu were tested at 225° and 2×106 A/cm2. For the Cu-containing samples, two different initial Cu distributions were tested: one in which the Cu was quenched into supersaturated solution within the Al grains (no precipitates) and another with many small, closely-spaced Al2Cu precipitates. We find that Cu still improves the mean time to fail of bamboo lines, although not as dramatically as in polygranular lines. More importantly, it significantly decreases the standard deviation in failure time, thus increasing the time to the first failure. Unlike in polygranular lines, increasing the Cu concentration from 0.5 to 0.9 wt. % has little effect on lifetime, and deliberately forming Cu precipitates prior to electromigration stressing reduces lifetimes. The best performance for submicron, highly bamboo runners was obtained from Al(0.5 wt. % Cu) with no precipitates prior to electromigration stressing.
Dependence of Strain and Plasticity During Thermal Cycling of Different Aluminum Metallization on Alloy Composition, Passivation Material and Passivation Geometry
Authors: Nielen Heiko , Göbel Herbert , Eppler Ingo , Schroeder Herbert , Schilling Werner 
Published: February 2013

ABSTRACTStress-induced voiding and shear plasticity of passivated metal lines during thermal cycling should be dependent on various properties of both, metallization and passivation, such as geometry and elastic constants and on the flow stress of the metal lines. Therefore we performed strain measurements on passivated lines of various aluminum-alloys with different passivation materials by x-ray diffraction during thermal cycling between RT and 420°C.As samples we used an array of 1μm wide and 0.8μm thick parallel lines, 1μm apart. As metallization sputter deposited Al, AlCu(0.5wt%), AlCu(1.0wt%), and AlSi(1.0wt%)Cu(0.5wt%) on a Ti/TiN diffusion barrier were used and passivated with different combinations of silicon-oxide/silicon-nitride and different geometries. To account for the interaction metal-passivation FEM calculations have been performed and the formalism of “eigenstrains” has been used to evaluate the voiding and shear plasticity separately.First results show a significant dependence of the strain on the passivating temperature (higher passivating temperature induces higher strain at RT) as well as on the passivation material and geometry. Plastic shear deformation is mostly influenced by the passivation geometry. Passivation composition shows smaller but also visible effects for plasticity whereas alloy composition seems to have no influence on any measured elastic and calculated plastic behavior of the metal lines within the errors.
The Geography of Violence, Alcohol Outlets, and Drug Arrests in Boston
Authors: Lipton Robert , Yang Xiaowen , A. Braga Anthony , Goldstick Jason , Newton Manya , Rura Melissa 
Published: February 2013

Objectives. We examined the relationship between alcohol outlets, drug markets (approximated by arrests for possession and trafficking), and violence in Boston, Massachusetts, in 2006. We analyzed geographic and environmental versus individual factors related to violence and identified areas high in violent crime. Methods. We used data from the Boston Police Department, US Census, and Massachusetts State Alcohol Beverage Control Commission. Spatial modeling was employed at the block group level, and violent crime, alcohol outlets, and drug markets were mapped. Results. Relative to other block groups, block groups in the highest decile of violent crime (n = 55) were found to be poorer (e.g., lower incomes, higher percentages of vacant homes), and they had greater numbers of alcohol outlets and higher drug arrest rates. Alcohol outlets and drug possession and trafficking arrests were predictive of violent crime. Also, spatial effects resulting from neighboring block groups were related to violent crime. Both alcohol outlet density and type were associated with violent crime in a differentiated and complex way. Conclusions. With drug possession and trafficking arrests as a proxy for drug markets, spatial relationships between alcohol outlets and violence were found in addition to typical sociodemographic predictors.
The Neighborhood Context of Homelessness
Authors: Alexander-Eitzman Ben , Pollio David E. , North Carol S. 
Published: February 2013

Objectives. We examined and compared the changing neighborhood characteristics of a group of homeless adults over time.Methods. We collected the addresses of previous housing and sleep locations from a longitudinal study of 400 homeless adults in the St. Louis, Missouri, region and compared census measures of housing and economic opportunities at different points along individual pathways from housing to homelessness and at 1- and 2-year follow-up interviews.Results. Sleep locations of homeless adults were much more concentrated in the urban core at baseline than were their previous housed and follow-up locations. These core areas had higher poverty, unemployment, and rent-to-income ratios and lower median incomes.Conclusions. The spatial concentration of homeless adults in areas with fewer opportunities and more economic and housing distress may present additional barriers to regaining stable housing and employment. A big-picture spatial and time-course viewpoint is critical for both policymakers and future homelessness researchers.
Improving the Environmental Quality Component of the County Health Rankings Model
Authors: Hendryx Michael , Ahern Melissa M. , Zullig Keith J. 
Published: February 2013

Objectives. We examined the association between environmental quality measures and health outcomes by using the County Health Rankings data, and tested whether a revised environmental quality measure for 1 state could improve the models. Methods. We conducted state-by-state, county-level linear regression analyses to determine how often the model’s 4 health determinants (social and economic factors, health behaviors, clinical care, and physical environment) were associated with mortality and morbidity outcomes. We then developed a revised measure of environmental quality for West Virginia, and tested whether the revised measure was superior to the original measure. Results. Measures of social and economic conditions, and health behaviors, were related to health outcomes in 58% to 88% of state models; measures of environmental quality were related to outcomes in 0% to 8% of models. In West Virginia, the original measure of environmental quality was unrelated to any of the 8 health outcome measures, but the revised measure was significantly related to all 8. Conclusions. The County Health Rankings model underestimates the impact of the physical environment on public health outcomes. Suggestions for other data sources that may contribute to improved measurement of the physical environment are provided.
Association of Posttraumatic Stress Disorder and Depression With All-Cause and Cardiovascular Disease Mortality and Hospitalization Among Hurricane Katrina Survivors With End-Stage Renal Disease
Authors: Edmondson Donald , Gamboa Christopher , Cohen Andrew , Anderson Amanda H. , Kutner Nancy , Kronish Ian , Mills Mary A. , Muntner Paul 
Published: February 2013

Objectives. We determined the association of psychiatric symptoms in the year after Hurricane Katrina with subsequent hospitalization and mortality in end-stage renal disease (ESRD) patients. Methods. A prospective cohort of ESRD patients (n = 391) treated at 9 hemodialysis centers in the New Orleans, Louisiana, area in the weeks before Hurricane Katrina were assessed for posttraumatic stress disorder (PTSD) and depression symptoms via telephone interview 9 to 15 months later. Two combined outcomes through August 2009 (maximum 3.5-year follow-up) were analyzed: (1) all-cause and (2) cardiovascular-related hospitalization and mortality. Results. Twenty-four percent of participants screened positive for PTSD and 46% for depression; 158 participants died (79 cardiovascular deaths), and 280 participants were hospitalized (167 for cardiovascular-related causes). Positive depression screening was associated with 33% higher risk of all-cause (hazard ratio [HR] = 1.33; 95% confidence interval [CI] = 1.06, 1.66) and cardiovascular-related hospitalization and mortality (HR = 1.33; 95% CI = 1.01, 1.76). PTSD was not significantly associated with either outcome. Conclusions. Depression in the year after Hurricane Katrina was associated with increased risk of hospitalization and mortality in ESRD patients, underscoring the long-term consequences of natural disasters for vulnerable populations.
The Statin–Iron Nexus: Anti-Inflammatory Intervention for Arterial Disease Prevention
Authors: Zacharski Leo R. , DePalma Ralph G. , Shamayeva Galina , Chow Bruce K. 
Published: February 2013

Objectives. We postulated the existence of a statin–iron nexus by which statins improve cardiovascular disease outcomes at least partially by countering proinflammatory effects of excess iron stores.Methods. Using data from a clinical trial of iron (ferritin) reduction in advanced peripheral arterial disease, the Iron and Atherosclerosis Study, we compared effects of ferritin levels versus high-density lipoprotein to low-density lipoprotein ratios (both were randomization variables) on clinical outcomes in participants receiving and not receiving statins.Results. Statins increased high-density lipoprotein to low-density lipoprotein ratios and reduced ferritin levels by noninteracting mechanisms. Improved clinical outcomes were associated with lower ferritin levels but not with improved lipid status.Conclusions. There are commonalities between the clinical benefits of statins and the maintenance of physiologic iron levels. Iron reduction may be a safe and low-cost alternative to statins.
Neighborhood Social Capital, Neighborhood Attachment, and Dental Care Use for Los Angeles Family and Neighborhood Survey Adults
Authors: Chi Donald L. , Carpiano Richard M. 
Published: February 2013

Objectives. We tested the hypothesis that neighborhood-level social capital and individual-level neighborhood attachment are positively associated with adult dental care use. Methods. We analyzed data from the 2000–2001 Los Angeles Family and Neighborhood Survey that were linked to US Census Bureau data from 2000 (n = 1800 adults aged 18–64 years across 65 neighborhoods). We used 2-level hierarchical logistic regression models to estimate the odds of dental use associated with each of 4 forms of social capital and neighborhood attachment. Results. After adjusting for confounders, the odds of dental use were significantly associated with only 1 form of social capital: social support (adjusted odds ratio [AOR] = 0.85; 95% confidence interval [CI] = 0.72, 0.99). Individual-level neighborhood attachment was positively associated with dental care use (AOR = 1.05; 95% CI = 1.01, 1.10). Conclusions. Contrary to our hypothesis, adults in neighborhoods with higher levels of social capital, particularly social support, were significantly less likely to use dental care. Future research should identify the oral health–related attitudes, beliefs, norms, and practices in neighborhoods and other behavioral and cultural factors that moderate and mediate the relationship between social capital and dental care use.
Ethnicity and Postmigration Health Trajectory in New Immigrants to Canada
Authors: Kim Il-Ho , Carrasco Christine , Muntaner Carles , McKenzie Kwame , Noh Samuel 
Published: February 2013

Objectives. In this prospective cohort study, we examined the trajectory of general health during the first 4 years after new immigrants’ arrival in Canada. We focused on the change in self-rated health trajectories and their gender and ethnic disparities. Methods. Data were derived from the Longitudinal Survey of Immigrants to Canada and were collected between April 2001 and November 2005 by Statistics Canada. We used weighted samples of 3309 men and 3351 women aged between 20 and 59 years. Results. At arrival, only 3.5% of new immigrants rated their general health as poor. Significant and steady increases in poor health were revealed during the following 4 years, especially among ethnic minorities and women. Specifically, we found a higher risk of poor health among West Asian and Chinese men and among South Asian and Chinese women than among their European counterparts. Conclusions. Newly arrived immigrants are extremely healthy, but the health advantage dissipates rapidly during the initial years of settlement in Canada. Women and minority ethnic groups may be more vulnerable to social changes and postmigration settlement.
The Provision of Comprehensive Reproductive Health Services in Los Angeles: A Physician’s Perspective
Authors: Natavio Melissa F. 
Published: February 2013

There are very few legal restrictions to obtaining an abortion in the state of California. However, women who reside in the highly populated and diverse county of Los Angeles may face barriers to obtaining comprehensive reproductive health services. In particular, women may face linguistic, cultural, and socioeconomic barriers, among others, that contribute to disparities in reproductive health and to access to safe abortion. In the era of health care reform, opportunities to address these health disparities exist, but access to abortion remains a challenge.
Longitudinal Effects of Universal Preventive Intervention on Prescription Drug Misuse: Three Randomized Controlled Trials With Late Adolescents and Young Adults
Authors: Spoth Richard , Trudeau Linda , Shin Chungyeol , Ralston Ekaterina , Redmond Cleve , Greenberg Mark , Feinberg Mark 
Published: February 2013

Objectives. We examined long-term prescription drug misuse outcomes in 3 randomized controlled trials evaluating brief universal preventive interventions conducted during middle school. Methods. In 3 studies, we tested the Iowa Strengthening Families Program (ISFP); evaluated a revised ISFP, the Strengthening Families Program: For Parents and Youth 10–14 plus the school-based Life Skills Training (SFP 10–14 + LST); and examined the SFP 10–14 plus 1 of 3 school-based interventions. Self-reported outcomes were prescription opioid misuse (POM) and lifetime prescription drug misuse overall (PDMO). Results. In study 1, ISFP showed significant effects on POM and PDMO, relative reduction rates (RRRs; age 25 years) of 65%, and comparable benefits for higher- and lower-risk subgroups. In study 2, SFP 10–14 + LST showed significant or marginally significant effects on POM and PDMO across all ages (21, 22, and 25 years); higher-risk participants showed stronger effects (RRRs = 32%–79%). In study 3, we found significant results for POM and PDMO (12th grade RRRs = 20%–21%); higher-risk and lower-risk participants showed comparable outcomes. Conclusions. Brief universal interventions have potential for public health impact by reducing prescription drug misuse among adolescents and young adults.
Comparative Efficacy and Safety Study of Two Chondroitin Sulfate Preparations from Different Origin (Avian and Bovine) in Symptomatic Osteoarthritis of the Knee
Authors: Fardellone Patrice , Zaim Mohammed , Saurel Anne-Sophie , Maheu Emmanuel 
Published: February 2013

Introduction:Some argued that clinical efficacy of Chondroitin Sulfate (CS) could vary upon the product origin. The objective of this trial is to compare the effect of 2 CS medicinal products from different origin: Structum® (avian, 1000mg/day) and Chondrosulf® (bovine, 1200mg/day).

Methods:This was a randomized, double-blind, double placebo, active-controlled, parallel-group study using a non-inferiority design. Symptomatic osteoarthritis of the knee patients, according to American College of Rheumatology criteria, aged 50-80 years received either Structum® (500mg BID) or Chondrosulf® (400mg TID) during 24 weeks. Inclusion criteria were: global pain in the target knee ≥ 40mm on a Visual Analog Scale (VAS 0-100), a Lequesne’s Algofunctional Index (LFI) score ≥ 7 (range: 0-24) and a radiological Kellgren-Lawrence grade 2 or 3. Primary outcome was the mean change over 24 weeks of pain VAS and LFI score. Secondary outcomes were patient’s and physician’s global assessments, Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society International responders rate, analgesics intake and Medical Outcomes Survey Short-Form 12 (SF-12). Safety was assessed by recording adverse events. A non-inferiority test was performed on the Structum®-Chondrosulf® difference for VAS and LFI score changes. Predefined non inferiority limit was settled as the lower limit of the 95% CI above -5mm and -1pt for pain VAS and LFI score respectively.

Results:837 patients were randomized: 817 available for the full analysis dataset (FAS), 692 for the per protocol (PP) analysis. No statistical and clinical differences were observed for demographics and disease characteristics between the 2 groups. PP analysis showed no difference between groups on mean variations of pain VAS or LFI scores over 24 weeks. Mean Pain VAS decreased by 23.9mm (17.5) in Structum® group and 23.8mm (17.2) in Chondrosulf® group (difference: 0.012 [CI95%: -2.6 ; 2.6]). Mean LFI score decreased by 3.2 (2.4) and 3.1 (2.4) respectively (difference: 0.139 [CI95%: -0.2 ; 0.5]). The lower limits of the 2 CI were above predefined non inferiority margin, which demonstrated the non inferiority of Structum® in comparison with Chondrosulf®. FAS analysis gave similar results. Secondary efficacy outcomes analysis showed the same trends. Responders rate were 76.3% and 73.8% respectively (PP, W24). Treatments were well tolerated: 2.4% in Structum® group and 4.5% in Chondrosulf® group withdrew from the study for safety reasons.

Conclusion:Structum® and Chondrosulf® were equally effective in reducing functional impairment and relieving pain over 6 months in knee osteoarthritis patients, without any safety concerns.

Trial Registration:http://www.controlled-trials.com Number: ISRCTN04305346.
The Benefits of Conservative Accounting to Shareholders: Evidence from the Financial Crisis
Authors: Francis Bill , Hasan Iftekhar , Wu Qiang 
Published: February 2013

SYNOPSIS
Using the recent financial crisis as a natural quasi-experiment we test whether, and to what extent, conservative accounting affects shareholder value. We find that there is a significantly positive and economically meaningful relation between conservatism and firm stock performance during the current crisis. The result holds for alternative measures of conservatism and is validated in a series of robustness checks. We further find that the relation between conservatism and firm value is more pronounced for firms with weaker corporate governance or higher information asymmetry. Overall, our paper complements LaFond and Watts (2008) by providing empirical evidence to their argument that conservatism is an efficient governance mechanism to mitigate information risk and control for agency problems, and that shareholders benefit from it.
JEL Classifications: M41; M48; G01.
Connections between connected topological spaces on the set of positive integers
Authors: Szczuka Paulina 
Published: February 2013

Abstract
In this paper we introduce a connected topology T on the set ℕ of positive integers whose base consists of all arithmetic progressions connected in Golomb’s topology. It turns out that all arithmetic progressions which are connected in the topology T form a basis for Golomb’s topology. Further we examine connectedness of arithmetic progressions in the division topology T′ on ℕ which was defined by Rizza in 1993. Immediate consequences of these studies are results concerning local connectedness of the topological spaces (ℕ, T) and (ℕ, T′).