bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biokinetics of cadmium and zinc in a marine bacterium: Influences of metal interaction and pre-exposure
Authors: Chen Dongshi , Qian Pei-Yuan , Wang Wen-Xiong 
Published: April 2008

Abstract
The uptake kinetics of Cd and Zn, as influenced by metal interaction and metal pre-exposure, was examined in the gram-positive marine bacterium Bacillus firmus over a wide range of ambient free-Cd and -Zn concentrations. Bacteria were exposed to experimental media with different concentrations of Cd and Zn over a short, 15-min period. Zinc was found to be an effective competitive inhibitor of Cd uptake when the Zn2+ concentration ([Zn2+]) was increased to 10−8 M, whereas the Cd concentration (ranging from 10−9 to 10−6 M) did not affect Zn uptake. Inhibition of Cd uptake was dependent on [Zn2+] instead of the [Zn2+] to Cd2+ concentration ratio. Cadmium uptake at different [Zn2+] was significantly inhibited by a sulfur ligand (SH) blocker (N-ethylmaleimide) and a Ca-channel blocker (lanthanum), suggesting that competition between Cd and Zn most likely occurred via binding to the same transport sites. Cadmium efflux also was determined in the presence of different [Zn2+]. A biphasic depuration of Cd was found when [Zn2+] was greater than 10−8 M, whereas the calculated Cd efflux rate was independent of [Zn2+]. We further exposed B. firmus at different Cd or Zn concentrations for 24 h, then determined the metal uptake and efflux kinetics as well as the metallothionein (MT) induction. Both the Cd and Zn cellular concentrations increased with greater exposed metal concentration, but the MT levels and efflux were little affected by the elevated metal concentration. To some extent, however, the Cd uptake was reduced with an elevated intracellular Zn concentration, suggesting that at high Cd concentrations, intracellular Zn can suppress the Cd uptake in B. firmus. These results help to understand the interactions of metals in the marine environments.
Distribution and variance/covariance structure of pesticide environmental fate data
Authors: Spurlock Frank 
Published: April 2008

Abstract
Hydrophobicity, persistence, and volatility data for individual pesticides are widely used in risk assessment and transport modeling, so it is important to understand their distribution, variation, and covariation. Correlations (normalized covariance) among properties across a range of multiple pesticides are also important for understanding fundamental relationships among the properties. For the present study, multiple determinations of 11 physicochemical properties of 262 individual pesticides were compiled, primarily from registrant submissions. A Z-score normality analysis indicates that, barring specific data to the contrary, log normality is a reasonable assumption for three properties commonly treated as random variables in modeling: Organic carbon-normalized soil sorption coefficient, aerobic soil metabolism half-life, and field dissipation half-life. Various percentiles for coefficients of variation of the variables are provided, allowing probabilistic modelers to choose realistic population parameters for sampling distributions. A second data set consisting of median values of individual properties for each pesticide was used to investigate the covariance structure of eight of the most important fate properties across 172 pesticides using correlation analysis and exploratory common factor analysis. That analysis demonstrated the use of common factor analysis for reducing the dimensionality of multicollinear environmental fate data, yielding three new orthogonal variables containing most of the information in the original data, and provided insight into the fundamental data structure.
Impacts of some environmentally relevant parameters on the sorption of polycyclic aromatic hydrocarbons to aqueous suspensions of fullerene
Authors: Hu Xialin , Liu Jingfu , Mayer Philipp , Jiang Guibin 
Published: April 2008

Abstract
The wide application of engineered carbon nanomaterials (CNMs), such as fullerene (C60), inevitably will result in their introduction into the aqueous environment. It is likely CNMs will associate with abundant natural organic matter (NOM) and engineered surfactants to form stable aqueous suspensions through various environmental processes. The present study reveals that sorption of polycyclic aromatic hydrocarbons (PAHs) to fullerene resulted in a remarkable decline of freely dissolved PAH concentrations. For the three PAHs studied (phenanthrene, fluoranthene, and chrysene) with log KOW in the range of 4.56 to 5.81, the measured sorption coefficients to aqueous suspensions of fullerene (log KC60 = 4.71–5.48) were close to that of dissolved organic carbon (DOC) from Aldrich humic acid (log KDOC = 4.48–5.91). Aqueous suspensions of fullerene were stable for a wide range of pH (3.0–11.0) and salinity conditions (0–25 mM NaCl), and the pH and salinity had minor effects on the sorption of PAHs to aqueous suspensions of fullerene. The addition of humic acids (5 mg/L DOC) to the fullerene (5 mg/L) suspensions resulted in an additional reduction of freely dissolved PAH concentrations. The high PAH sorption coefficients to suspended fullerene suggest that the release of fullerene to the aquatic environment might affect PAH fate and exposures.
Ethics in Public Health Research
Authors: Myers Julie , Frieden Thomas R. , Bherwani Kamal M. , Henning Kelly J. 
Published: April 2008

Public health agencies increasingly use electronic means to acquire, use, maintain, and store personal health information. Electronic data formats can improve performance of core public health functions, but potentially threaten privacy because they can be easily duplicated and transmitted to unauthorized people. Although such security breaches do occur, electronic data can be better secured than paper records, because authentication, authorization, auditing, and accountability can be facilitated. Public health professionals should collaborate with law and information technology colleagues to assess possible threats, implement updated policies, train staff, and develop preventive engineering measures to protect information. Tightened physical and electronic controls can prevent misuse of data, minimize the risk of security breaches, and help maintain the reputation and integrity of public health agencies.
Reduction of State Victim Compensation Disparities in Disadvantaged Crime Victims Through Active Outreach and Assistance: A Randomized Trial
Authors: Alvidrez Jennifer , Shumway Martha , Boccellari Alicia , Green Jon Dean , Kelly Vanessa , Merrill Gregory 
Published: April 2008

Objectives. We examined whether providing active outreach and assistance to crime victims as part of comprehensive psychosocial services reduced disparities in access to state compensation funds. Methods. We analyzed data from a randomized trial of injured crime victims (N = 541) and compared outcomes from comprehensive psychosocial services with usual community care. We examined the impact of outreach and assistance on disparities in applying for victim compensation by testing for interactions between victim characteristics and treatment condition in logistic regression analyses. Results. Victims receiving comprehensive services were much more likely to apply for victim compensation than were victims receiving usual care. Comprehensive services decreased disparities associated with younger age, lower levels of education, and homelessness. Conclusions. State-level victim compensation funds are available to help individuals recover physically, psychologically, and financially from crime victimization. However, few crime victims apply for victim compensation, and there are particularly low application rates among young, male, ethnic minority, and physical assault victims. Active outreach and assistance can address disparities in access to victim compensation funds for disadvantaged populations and should be offered more widely to victims of violent crime.
Being Poor and Coping With Stress: Health Behaviors and the Risk of Death
Authors: Krueger Patrick M. , Chang Virginia W. 
Published: April 2008

Objectives. Individuals may cope with perceived stress through unhealthy but often pleasurable behaviors. We examined whether smoking, alcohol use, and physical inactivity moderate the relationship between perceived stress and the risk of death in the US population as a whole and across socioeconomic strata. Methods. Data were derived from the 1990 National Health Interview Survey’s Health Promotion and Disease Prevention Supplement, which involved a representative sample of the adult US population (n=40335) and was linked to prospective National Death Index mortality data through 1997. Gompertz hazard models were used to estimate the risk of death. Results. High baseline levels of former smoking and physical inactivity increased the impact of stress on mortality in the general population as well as among those of low socioeconomic status (SES), but not middle or high SES. Conclusions. The combination of high stress levels and high levels of former smoking or physical inactivity is especially harmful among low-SES individuals. Stress, unhealthy behaviors, and low SES independently increase risk of death, and they combine to create a truly disadvantaged segment of the population.
Long-Term Trends in Adolescent and Young Adult Smoking in the United States: Metapatterns and Implications
Authors: Nelson David E. , Mowery Paul , Asman Kat , Pederson Linda L. , O’Malley Patrick M. , Malarcher Ann , Maibach Edward W. , Pechacek Terry F. 
Published: April 2008

Objectives. We sought to describe long-term adolescent and young adult smoking trends and patterns. Methods. We analyzed adolescent data from Monitoring the Future, 1976 to 2005, and young adult (aged 18–24 years) data from the National Health Interview Survey, 1974 to 2005, overall and in subpopulations to identify trends in current cigarette smoking prevalence. Results. Five metapatterns emerged: we found (1) a large increase and subsequent decrease in overall smoking over the past 15 years, (2) a steep decline in smoking among Blacks through the early 1990s, (3) a gender gap reversal among older adolescents and young adults who smoked over the past 15 years, (4) similar trends in smoking for most subgroups since the early 1990s, and (5) a large decline in smoking among young adults with less than a high school education. Conclusions. Long-term patterns for adolescent and young adult cigarette smoking were decidedly nonlinear, and we found evidence of a cohort effect among young adults. Continued strong efforts and a long-term societal commitment to tobacco use prevention are needed, given the unprecedented declines in smoking among most subpopulations since the mid- to late 1990s.
The Effect of Vaccinated Children on Increased Hepatitis B Immunization Among High-Risk Adults
Authors: Koya Deepika L. , Hill Elizabeth G. , Darden Paul M. 
Published: April 2008

Objectives. We sought to examine trends in hepatitis B virus (HBV) vaccination among high-risk adults and assess the potential effect vaccinated adolescents have on these trends as they age. Methods. We used data from the National Health Interview Survey 2000, 2002, and 2004 to examine trends in HBV vaccination among high-risk adults aged 18 to 49 years and in age subgroups (18–29, 30–39, and 40–49 years). We investigated temporal differences in vaccination rates for the 18- to 29-year-old cohort with model-based linear contrasts constructed from a logistic regression model with age and survey year as predictors. Results. There was a significant increasing trend in vaccination prevalence across the 3 survey years (32.6%, 35.3%, and 41.4%; trend test, P=.001). We found that respondents aged 18 to 29 years were more likely to be vaccinated in 2004 than in 2000, after adjusting for relevant confounders (odds ratio=1.73; 95% confidence interval=1.14, 2.6); there was no significant increase in vaccination for the other cohorts. Conclusions. A cohort effect, in which successfully vaccinated adolescents have reached young adulthood, contributes significantly to recent trends showing improved HBV vaccination among high-risk adults.
Health Effects of Exposure to Water-Damaged New Orleans Homes Six Months After Hurricanes Katrina and Rita
Authors: Cummings Kristin J. , Cox-Ganser Jean , Riggs Margaret A. , Edwards Nicole , Hobbs Gerald R. , Kreiss Kathleen 
Published: April 2008

Objectives. We investigated the relation between respiratory symptoms and exposure to water-damaged homes and the effect of respirator use in posthurricane New Orleans, Louisiana. Methods. We randomly selected 600 residential sites and then interviewed 1 adult per site. We created an exposure variable, calculated upper respiratory symptom (URS) and lower respiratory symptom (LRS) scores, and defined exacerbation categories by the effect on symptoms of being inside water-damaged homes. We used multiple linear regression to model symptom scores (for all participants) and polytomous logistic regression to model exacerbation of symptoms when inside (for those participating in clean-up). Results. Of 553 participants (response rate=92%), 372 (68%) had participated in clean-up; 233 (63%) of these used a respirator. Respiratory symptom scores increased linearly with exposure (P<.05 for trend). Disposable-respirator use was associated with lower odds of exacerbation of moderate or severe symptoms inside water-damaged homes for URS (odds ratio (OR)=.51; 95% confidence interval (CI)=0.24, 1.09) and LRS (OR=0.33; 95% CI=0.13, 0.83). Conclusions. Respiratory symptoms were positively associated with exposure to water-damaged homes, including exposure limited to being inside without participating in clean-up. Respirator use had a protective effect and should be considered when inside water-damaged homes regardless of activities undertaken.
Status of Influenza and Pneumococcal Vaccination Among Older American Indians and Alaska Natives
Authors: Lindley Megan C. , Groom Amy V. , Wortley Pascale M. , Euler Gary L. 
Published: April 2008

Objectives. We sought to estimate the influenza and pneumococcal vaccination coverage among older American Indian and Alaska Native (AIAN) adults nationally and the impact of sociodemographic factors, variations by geographic region, and access to services on vaccination coverage. Methods. We obtained our sample of 1981 AIAN and 179845 White respondents 65 years and older from Behavioral Risk Factor Surveillance System data from 2003 to 2005. Logistic regression provided predictive marginal vaccination coverage for each covariate and adjusted for demographic characteristics and access to care. Results. Unadjusted influenza coverage estimates were similar between AIAN and White respondents (68.1% vs 69.5%), but pneumococcal vaccination was lower among AIAN respondents (58.1% vs 67.2%; P<.01). After multivariable adjustment for sociodemographic characteristics, self-reported coverage for both vaccines was statistically similar between AIAN and White adults. Conclusions. Although there was no disparity in influenza coverage, pneumococcal coverage was lower among AIAN than among White respondents, probably because of sociodemographic risk factors. Regional variation indicates a need to monitor coverage and target interventions to reduce disparities within geographically and culturally diverse subpopulations of AIAN persons.
Trends in Recorded Influenza Mortality: United States, 1900–2004
Authors: Doshi Peter 
Published: April 2008

Objectives. I sought to describe trends in historical influenza mortality data in the United States since 1900 and compare pandemic with nonpandemic influenza seasons. Methods. I compiled a database of monthly influenza-classed death rates from official US mortality tables for the years 1900 to 2004 (1905–1909 excluded), from which I calculated adjusted influenza season (July 1–June 30) mortality rates. Results. An overall and substantial decline in influenza-classed mortality was observed during the 20th century, from an average seasonal rate of 10.2 deaths per 100 000 population in the 1940s to 0.56 per 100 000 by the 1990s. The 1918–1919 pandemic stands out as an exceptional outlier. The 1957–1958 and 1968–1969 influenza pandemic seasons, by contrast, displayed substantial overlap in both degree of mortality and timing compared with nonpandemic seasons. Conclusions. The considerable similarity in mortality seen in pandemic and non-pandemic influenza seasons challenges common beliefs about the severity of pandemic influenza. The historical decline in influenza-classed mortality rates suggests that public health and ecological factors may play a role in influenza mortality risk. Nevertheless, the actual number of influenza-attributable deaths remains in doubt.
New York City’s Initiatives on Diabetes and HIV/AIDS: Implications for Patient Care, Public Health, and Medical Professionalism
Authors: Goldman Janlori , Kinnear Sydney , Chung Jeannie , Rothman David J. 
Published: April 2008

Two recent New York City Department of Health and Mental Hygiene initiatives expanded the mission and scope of public health, with implications for both New York and the nation. The programs target diabetes and HIV/AIDS for greater systemic and expanded reporting, surveillance, and intervention. These initiatives do not balance heightened surveillance and intervention with the provision of meaningful safeguards or resources for prevention and treatment. The programs intrude on the doctor–patient relationship and may alienate the very patients and health professionals they aim to serve. Better models are available to achieve their intended goals. These initiatives should be reconsidered so that such an expansion of public health authority in New York City does not become part of a national trend.
Correlates of the Stages of Change for Physical Activity in a Population Survey
Authors: Garber Carol Ewing , Allsworth Jenifer E. , Marcus Bess H. , Hesser Jana , Lapane Kate L. 
Published: April 2008

Objectives. We sought to identify variables associated with being in a particular stage of change for physical activity—a measure of behavioral intention to engage in regular physical activity. Understanding behavioral intentions can be useful in explaining why individuals are physically inactive or active. Methods. Data from the Rhode Island 2000 Behavioral Risk Factor Surveillance System were used to evaluate predictors of stage of change for physical activity. There were 3454 observations in the data set, representing a weighted population of 742636 people. Estimates were obtained from polytomous multiple logistic models. Results. Being a woman, Hispanic, non-Hispanic Black, and older than 55 years of age were associated with being in precontemplation and contemplation stages of change rather than maintenance. Self-perceived health status and rarely feeling healthy or full of energy were strongly predictive of stage of change. Having a health limitation was a dichotomous predictor, predicting being in action and precontemplation stages. Conclusions. Several sociodemographic and health variables were associated with varying patterns of stages of change for physical activity. The complexity of individual intentions for physical activity provides evidence for the potential existence of mediating, effect-modifying, and confounding variables that differ depending on individual characteristics.
Temperature and electric field dependences of the mobility of electrons in vertical transport in GaAs/Ga1−y
AlyAs barrier structures containing quantum wells
Authors: Altunöz Safi , Çelik Hüseyin , Cankurtaran Mehmet 
Published: April 2008

Abstract
The mobility of electrons in vertical transport in GaAs/Ga1−y
AlyAs barrier structures was investigated using geometric magnetoresistance measurements in the dark. The samples studied had Ga1−y
AlyAs (0 ≤ y ≤ 0:26) linearly graded barriers between the n+-GaAs contacts and the Ga0:74Al0:26As central barrier, which contain N
w (=0, 2, 4, 7 and 10) n-doped GaAs quantum wells. The mobility was determined as functions of (i) temperature (80–290 K) at low applied voltage (0.01–0.1 V) and (ii) applied voltage (0.005–1.6 V) at selected temperatures in the range 3.5–290 K. The experimental results for the temperature dependence of low-field mobility suggest that space-charge scattering is dominant in the samples with N
w=0 and 2, whereas ionized impurity scattering is dominant in the samples with N
w=4, 7 and 10. The effect of polar optical phonon scattering on the mobility becomes significant in all barrier structures at temperatures above about 200 K. The difference between the measured mobility and the calculated total mobility in the samples with N
w=4, 7 and 10, observed above 200 K, is attributed to the reflection of electrons from well-barrier interfaces in the quantum wells and interface roughness scattering. The rapid decrease of mobility with applied voltage at high voltages is explained by intervalley scattering of hot electrons.
Regeneration cycles of the keystone species Carnegiea gigantea are linked to worldwide volcanism
Authors: Drezner Taly Dawn , Balling Jr. Robert C. 
Published: April 2008

AbstractQuestion:We know of no study that has linked volcanic eruptions occurring anywhere worldwide and the local population cycles of any species. The keystone saguaro cactus (Carnegiea gigantea) establishes in cohorts. We test whether there is a statistical relationship between Carnegiea gigantea establishment and volcanic eruptions.Location:Northern Sonoran Desert, Arizona, USA.Methods:We use both a region‐wide dataset made up of 30 populations, and a dataset from a marginal site. We incorporate data for over 750 individuals over an area of more than 50 000 km2. We created a 111‐year time series of population peaks and troughs and correlated this over the 111‐year record with the annual Weighted Historical Dust Veil Index (WHDVI). A t‐test compared establishment patterns with the WHDVI.Results:We found a significant relationship between volcanism and C. gigantea regeneration at both the marginal site, and in the region‐wide dataset.Conclusions:We suggest that while different populations are influenced by temporary global temperature ameliorations to different extents, our results show that populations do derive significant benefits from volcanic eruptions that promote their regeneration over large portions of their range, as is also exhibited locally at our marginal site, where populations are most susceptible to the inhospitable conditions that are witnessed at the edge of their range. This paper draws a link between the population fluctuations and regeneration of a species locally with geologic events from distant parts of the earth.