bluuebunny/crossref_metadata_2025 huggingface dataset:
Disparities in Alcohol‐Related Problems Among White, Black, and Hispanic Americans
Authors: Mulia Nina , Ye Yu , Greenfield Thomas K. , Zemore Sarah E.
Published: January 2009

Background:  This study assesses racial/ethnic disparities in negative social consequences of drinking and alcohol dependence symptoms among white, black, and Hispanic Americans. We examine whether and how disparities relate to heavy alcohol consumption and pattern, and the extent to which social disadvantage (poverty, unfair treatment, and racial/ethnic stigma) accounts for observed disparities.

Methods:  We analyzed data from the 2005 U.S. National Alcohol Survey, a nationally representative telephone‐based survey of adults ages 18 and older (N = 6,919). Given large racial/ethnic differences in abstinence rates, core analyses were restricted to current drinkers (N = 4,080). Logistic regression was used to assess disparities in alcohol‐related problems at 3 levels of heavy drinking, measured using a composite variable incorporating frequency of heavy episodic drinking, frequency of drunkenness, and maximum amount consumed in a single day. A mediational approach was used to assess the role of social disadvantage.

Results:  African American and Hispanic drinkers were significantly more likely than white drinkers to report social consequences of drinking and alcohol dependence symptoms. Even after adjusting for differences in heavy drinking and demographic characteristics, disparities in problems remained. The racial/ethnic gap in alcohol problems was greatest among those reporting little or no heavy drinking, and gradually diminished to nonsignificance at the highest level of heavy drinking. Social disadvantage, particularly in the form of racial/ethnic stigma, appeared to contribute to racial/ethnic differences in problems.

Conclusions:  These findings suggest that to eliminate racial/ethnic disparities in alcohol‐related problems, public health efforts must do more than reduce heavy drinking. Future research should address the possibility of drink size underestimation, identify the particular types of problems that disproportionately affect racial/ethnic minorities, and investigate social and cultural determinants of such problems.
Competing Social Movements and Local Political Culture: Voting on Ballot Propositions to Ban Same‐Sex Marriage in the U.S. States*
Authors: Fleischmann Arnold , Moyer Laura
Published: January 2009

Objective.This article uses social movement theory to explain variation in local support for proposed constitutional amendments to ban same‐sex marriage in 22 states during 2004 and 2006.

Methods.The analysis uses OLS regression with county‐level data to explain variation in local support for the amendments.

Results.Support for the amendments in both years was positively related to the proportion of a county that was evangelical or Republican, but negatively related to its level of education and proportion of Catholics. Amendment support was positively related in only one year to the percentage of a county's population that was professional, young, black, in female‐headed households, and Mormon. Amendment support was negatively related to the concentration of gay organizations in 2006, but positively related to the presence of mega‐churches in 2006.

Conclusions.Community characteristics have a substantial effect on levels of support for same‐sex marriage bans, thus reinforcing the utility of cultural explanations of policy decisions.
Explaining Self‐Employment Success and Failure: Wal‐Mart Versus Starbucks, or Schumpeter Versus Putnam*
Authors: Goetz Stephan J. , Shrestha Sundar S.
Published: January 2009

Objectives.Two powerful socioeconomic innovations are sweeping the nation, led by Wal‐Mart Stores, Inc. and Starbucks Corp. These innovations both affect and are driven by profound labor market changes, but exactly how they affect self‐employment or entrepreneurship has not been investigated. We examine the independent effects of these phenomena on the returns to self‐employment, which is itself an underresearched topic in labor economics.

Methods.We apply spatial econometric analysis to data from more than 3,000 U.S. counties to analyze how big‐boxes and drinking places that facilitate social networking affect self‐employment earnings.

Findings.The presence of Wal‐Mart stores is associated with higher returns to self‐employment, whereas the results for coffee shops and drinking places are mixed. A negative interaction effect on earnings emerges when Wal‐Mart stores and drinking places exist in the same county.

Conclusions.We confirm both Schumpeter's and Putnam's assertions about the importance of creative destruction and social networking in raising the productivity of entrepreneurs, although the latter effect is not as clear‐cut as the former.
First Names and Crime: Does Unpopularity Spell Trouble?*
Authors: Kalist David E. , Lee Daniel Y.
Published: January 2009

Objective. We investigate the relationship between first name popularity and juvenile delinquency to test the hypothesis that unpopular names are positively correlated with crime.

Methods. To compare the names of juveniles in a state's population with the names of juveniles who received substantiated charges in that state's juvenile justice system, we construct a popularity name index. Regression analysis is used to examine the relationship among names, crime, and socioeconomic background of juveniles.

Results. The distribution of first names in the state's population is different from the names of juvenile delinquents. Our results show that unpopular names are positively correlated with juvenile delinquency for both blacks and whites.

Conclusions. Unpopular names are likely not the cause of crime but correlated with factors that increase the tendency toward juvenile delinquency, such as a disadvantaged home environment and residence in a county with low socioeconomic status.
Agenda Setting and State Policy Diffusion: The Effects of Media Attention, State Court Decisions, and Policy Learning on Fetal Killing Policy*
Authors: Oakley M. R.
Published: January 2009

Objectives. This study combines theories on agenda setting, policy innovation, and policy learning to develop an improved model of state policy change. The case of fetal killing policy change in the states is used to develop a model that incorporates national media attention and the decisions of state courts, in addition to policy learning variables that account for the policy changes of neighboring states and the passage of time.

Methods. I test the effect of national media attention, decisions by the courts, and the actions of neighboring states on the likelihood that states will change their fetal homicide policies. Using time‐series cross‐sectional data from 1970 to 2002, the model is tested using logistic regression analysis. In addition to testing the theories mentioned above, control variables in the model include citizen and government ideology and the percentage of state residents who are fundamentalist Protestants.

Results. Three of the four research hypotheses are supported by the statistical analysis. The results demonstrate that increased media attention to fetal homicide in a given year increases the likelihood that a state will change its policy the next year. Support is also found for the hypothesis that state court decisions will affect policy change. One of the control variables, government liberalism, is also found to decrease the likelihood that states will change their fetal homicide policies.

Conclusions. This study lends insight into why states change their policies by including agenda‐setting variables such as media attention and decisions made by the courts. States do react to the actions of the courts by making changes to policies affected by the decisions.
Sense of Coherence and Mood States: Exploring the Causal Relationships
Authors: Berger Rivka , Sarid Orly , Hurvitz Nancy , Anson Ofra
Published: January 2009

The current study seeks to explore the effect of an academic course on sense of coherence (SOC) and transitory mood states. Moreover, the causal relationships between SOC and transitory mood states was evaluated. Second‐year pharmacology students completed pencil‐and‐paper questionnaires at the beginning of the semester and 3‐1/2 months later. The study group (n = 37) participated in an academic course developed to teach cognitive behavior concept and practice, whereas the control group (n = 43) had additional sessions of laboratory work. SOC increased significantly after the course while tension–anxiety and confusion decreased significantly. Structural equation analyses in the study group suggested that SOC was modified by confusion and perceived stress. No such pattern was observed in the control group.
The Effect of Incentive Structure on Heuristic Decision Making: The Proportion Heuristic1
Authors: Oxoby Robert J.
Published: January 2009

When making judgments, individuals often utilize heuristics to interpret information. This paper reports on a series of experiments designed to test the ways in which incentive mechanisms influence the use of a particular heuristic in decision making. These experiments demonstrate how information regarding the number of available practice problems influences the behaviors of individuals preparing for an exam (the proportion heuristic). More importantly, the extent to which this information influences behavior depends critically on the way in which performance incentives are structured. In particular, relative compensation schemes magnify the influence of this heuristic, while joint compensation schemes dampen its influence. These results are discussed with respect to the literature on effective compensation.
The Hidden Prejudice in Selection: A Research Investigation on Skin Color Bias
Authors: Harrison Matthew S. , Thomas Kecia M.
Published: January 2009

In this era of affirmative action, racial discrimination in the workplace has been studied widely. A common negligence of these studies is that they disregard the subject of skin‐tone stratification, and present an analysis of discrimination based on treatment of Blacks and Whites (both as collective units); thereby overlooking a prevalent issue that has long existed in western culture—colorism. This study examined the influence of colorism on job selection, and discovered a significant preferential difference among Black applicants based on their skin complexion. The findings suggest that skin tone plays a considerable role in the favorability of a Black applicant; indicating that skin color is more salient and regarded more highly than one's educational background and prior work experience.
Control and Anticipation of Social Interruptions: Reduced Stress and Improved Task Performance1
Authors: Carton Andrew M. , Aiello John R.
Published: January 2009

Social interruptions are frequent occurrences that often have distressing consequences for employees, yet little research has gauged their effect on individuals. Participants were exposed to 2 social interruptions as they engaged in a computer task with an accepted performance goal. Participants who were able to anticipate social interruptions performed significantly better than did those who could not anticipate them. Participants who had the opportunity to prevent interruptions reported significantly less stress than those who did not have this opportunity. This reduction in stress resulted even when participants did not take advantage of this opportunity. Implications for job performance and job satisfaction are discussed. Organizational strategies for how leaders can help employees manage social interruptions are suggested.
The Structure of Negotiation: Lessons from El Salvador for Contemporary Conflict Resolution
Authors: Pugh Jeffrey
Published: January 2009

During more than a decade of violent conflict (1980–1992) involving the military, rebel forces, and paramilitary “death squads,” El Salvador suffered some 75,000 casualties, mostly civilians. After three years of negotiations, the government and the largest rebel group signed a historic comprehensive peace accord that brought an end to the war and instituted wide‐reaching political and social reforms. This agreement, and the peace process that produced it, has been widely hailed as a successful example of a negotiated end to civil war. In order to understand the conditions that led to the 1992 Chapultepec Peace Accords ending the war, this article tests ripeness theory in the context of the Salvadoran peace process.

This article affirms the validity of theories of ripeness and the mutually hurting stalemate as structural explanations for the initiation of dialogue and notes the role of “indicators of ripeness” in forcing the parties to recognize a hurting stalemate that may already exist. It also proposes several hypothesized explanations for the effectiveness of the Salvadoran negotiations themselves. These explanations include the presence of strong, empowered policy entrepreneurs on both sides with the political will and capability to make credible commitments; the combination of internal and external pressure for a negotiated solution that raised the cost of defection; and the active involvement, based on consent of both parties, of a neutral, empowered, and credible mediator who provided both technical assistance and vigilance to move the process forward. After analyzing the Salvadoran case through this theoretical lens, the article applies the same concepts to contemporary conflict cases such as Iraq and Colombia, discussing how the lessons learned in El Salvador do and do not provide instructive guidance for managing civil conflicts today.
Baboon carboxylesterases 1 and 2: sequences, structures and phylogenetic relationships with human and other primate carboxylesterases
Authors: Holmes Roger S. , Glenn Jeremy P. , VandeBerg John L. , Cox Laura A.
Published: January 2009

Background  Carboxylesterase (CES) is predominantly responsible for the detoxification of a wide range of drugs and narcotics, and catalyze several reactions in cholesterol and fatty acid metabolism. Studies of the genetic and biochemical properties of primate CES may contribute to an improved understanding of human disease, including atherosclerosis, obesity and drug addiction, for which non‐human primates serve as useful animal models.

Methods  We cloned and sequenced baboon CES1 and CES2 and used in vitro and in silico methods to predict protein secondary and tertiary structures, and examined evolutionary relationships for these enzymes with other primate and mouse CES orthologs.

Results and Conclusions  We found that baboon CES1 and CES2 proteins retained extensive similarity with human CES1 and CES2, shared key structural features reported for human CES1, and showed family specific sequences consistent with their multimeric and monomeric subunit structures respectively.
Partial least squares regression as an alternative to current regression methods used in ecology
Authors: Carrascal Luis M. , Galván Ismael , Gordo Oscar
Published: January 2009

This paper briefly presents the aims, requirements and results of partial least squares regression analysis (PLSR), and its potential utility in ecological studies. This statistical technique is particularly well suited to analyzing a large array of related predictor variables (i.e. not truly independent), with a sample size not large enough compared to the number of independent variables, and in cases in which an attempt is made to approach complex phenomena or syndromes that must be defined as a combination of several variables obtained independently. A simulation experiment is carried out to compare this technique with multiple regression (MR) and with a combination of principal component analysis and multiple regression (PCA+MR), varying the number of predictor variables and sample sizes. PLSR models explained a similar amount of variance to those results obtained by MR and PCA+MR. However, PLSR was more reliable than other techniques when identifying relevant variables and their magnitudes of influence, especially in cases of small sample size and low tolerance. Finally, we present one example of PLSR to illustrate its application and interpretation in ecology.
Animal response to nested self‐similar patches: a test with woolly bears
Authors: McClure Mark F. , Shipley Lisa A.
Published: January 2009

To gain insight into how animals respond to resource patchiness at different spatial scales, we envision their responses in environments comprised of nested, self‐similar patches. In these environments, all resources reside within the smallest patches, and resource density declines as a constant exponent of patch size. Accordingly, we use simple mathematical formulations to describe a self‐similar environment and a null model of how animals should respond to this environment if they do not perceive resource distribution. We then argue that animals that can perceive resource distribution should partition space by reducing the relative time searching between patches as patch size increases. On an experimental landscape, we found that woolly bear caterpillars Grammia geneura could partition space in this manner, but the range of patch sizes over which they did so tended to increase with resource aggregation. Nevertheless, scaling efficiency (i.e. the scaling of search time versus the scaling or resource density) was similar in all distributions when averaged over all patch sizes. These disparate patterns with similar outcomes resulted from differences in caterpillars’ abilities to discriminate spatially among patches of different sizes via their movement pathways, and differences in their use of speed to detect resource items. Our work is relevant to the characterization of resource availability from an animal's perspective, and to the linking of optimal foraging theory to the modeling of search behavior.
Effects of extrinsic and intrinsic factors on breeding success in a long lived seabird
Authors: Lewis Sue , Elston David A. , Daunt Francis , Cheney Barbara , Thompson Paul M.
Published: January 2009

There is growing concern over the impacts of climate change on animal species. Many studies have demonstrated impacts of climate change at the population level, and density dependent effects of climate are frequently reported. However, there is an increasing recognition of the differential impact of such factors on individuals since there is marked variation in individual performance. We investigated the relationships between breeding success and environmental conditions (winter NAO and one year lagged winter NAO) and intrinsic effects (colony size, pair bond duration, past breeding success rate) in the northern fulmar Fulmarus glacialis, using data from a long‐term study commenced in 1950. There was a negative trend in breeding success over time, and a negative relationship with winter NAO and lagged winter NAO, which themselves had shown positive increases over the study period. The effects of lagged winter NAO remained after accounting for the linear trend. There was no evidence of density dependence, with breeding success positively related to colony size. We found strong evidence that breeding success was negatively related to pair bond duration but positively related to past breeding success rate. There was also an interaction between these two intrinsic effects such that those pairs that had historically been successful maintained success with increasing pair bond duration, whereas less successful pairs showed a decline. The prediction that there would be a differential impact of extrinsic factors among pairs was supported by an interaction between past breeding success rate and winter NAO, such that pairs with low past success rate exhibited a sharp decline in breeding success with increasing winter NAO, whereas more successful pairs did not. It is critically important to understand interactions between extrinsic factors and individual heterogeneity since a differential impact on individuals will affect population structure, and hence population dynamics.
Density dependent dispersal decisions and the Allee effect
Authors: Fowler Mike S.
Published: January 2009

The decision to move between patches in the environment is among the most important life history choices an organism can make. I derive a new density dependent dispersal rule, and examine how dispersal decisions based on avoiding fitness loss associated with an Allee effect or competitive effects impact upon population dynamics in spatially structured populations with qualitatively different dynamics. I also investigate the effects of the number of patches in the system and a limit to the patch sampling time available to dispersers. Dispersing to avoid competitive pressures can destabilise otherwise stable population dynamics, and stabilise chaotic dynamics. Dispersing to avoid an Allee effect does not qualitatively change local population dynamics until eventually driving unstable populations to global extinction with a sufficiently high fitness threshold. A time limit for sampling can stabilise dynamics if dispersal is based on escaping the Allee effect, and rescue populations from global extinction. The results are sensitive to the number of patches available in the environment and suggest that dispersal to avoid an Allee effect will only arise under biologically plausible conditions, i.e. where there is a limit to the number of dispersal attempts that can be made between generations.
The effect of maximum bite force on alveolar bone morphology
Authors: Thongudomporn U , Chongsuvivatwong V , Geater AF
Published: January 2009

Structured Abstract

Authors –  Thongudomporn U, Chongsuvivatwong V, Geater AF

Objectives –  To investigate to what extent maximum bite force contributes to alveolar bone morphology parameters, i.e. alveolar thickness, shape and arch width.

Design –  An observational cross‐sectional survey.

Setting and Sample Population –  One hundred and fifty one 12‐ to 14‐year‐old students from a secondary school in Hatyai City, Songkhla Province, Thailand.

Material and Methods –  Height, weight and maximum bite force of each subject were recorded. Alveolar bone morphology parameters were measured from study models.

Results –  Maximum bite force moderately correlated with alveolar thickness and shape (r = 0.31–0.44, p < 0.001), but weakly correlated with arch width (r = 0.03–0.05, p > 0.05). After adjusting for gender and body mass index (BMI), the maximum bite force significantly determined alveolar thickness and shape (p < 0.001), accounting for 10–20% of the variations. Boys were associated with larger posterior arch width (p < 0.01), where BMI was not associated with alveolar bone morphology parameters (p > 0.01) after Bonferroni correction for multiple testing.

Conclusion –  Maximum bite force had a selective influence on alveolar thickness and shape, but not on arch width.
In‐vitro evaluation of the corrosion behavior of orthodontic brackets
Authors: Luft S , Keilig L , Jäger A , Bourauel C
Published: January 2009

Structured Abstract

Authors –  Luft S, Keilig L, Jäger A, Bourauel C

Objective –  The number of bracket systems for orthodontic therapy increases significantly. One major concern of newly developed orthodontic devices is aspects of corrosion and biocompatibility.

Material and Methods –  In this study, nine bracket systems made of different material and from various design principles were tested with respect to their corrosion behavior. Electrochemical and static immersion tests with subsequent measurement of nickel ion release were performed. In addition surface alterations of the brackets after corrosion were documented by scanning electron microscopy. Studies of corrosion behavior were performed according to the DIN/ISO standard 10271 for corrosion testing of dental materials.

Results –  All systems showed traces of corrosion after electrochemical testing. However, after static immersion testing only minor corrosion defects could be documented and the measured nickel ion release was far below critical limits.

Conclusions –  All tested systems seem to be biocompatible and applicable for orthodontic therapy. The measured nickel values are far below the daily dietary intake level. A static immersion test combined with the nickel ion release measurement seems to be more relevant for the determination of biocompatibility than the electrochemical testing.
Evolutionary origins of the purinergic signalling system
Authors: Burnstock G. , Verkhratsky A.
Published: January 2009

Purines appear to be the most primitive and widespread chemical messengers in the animal and plant kingdoms. The evidence for purinergic signalling in plants, invertebrates and lower vertebrates is reviewed. Much is based on pharmacological studies, but important recent studies have utilized the techniques of molecular biology and receptors have been cloned and characterized in primitive invertebrates, including the social amoebaDictyosteliumand the platyhelminthSchistosoma, as well as the green algaeOstreococcus, which resemble P2X receptors identified in mammals. This suggests that contrary to earlier speculations, P2X ion channel receptors appeared early in evolution, while G protein‐coupled P1 and P2Y receptors were introduced either at the same time or perhaps even later. The absence of gene coding for P2X receptors in some animal groups [e.g. in some insects, roundworms (Caenorhabditis elegans) and the plantArabidopsis] in contrast to the potent pharmacological actions of nucleotides in the same species, suggests that novel receptors are still to be discovered.
Co‐existence of divergent communities at natural boundaries: spider (Arachnida: Araneae) diversity across an alpine timberline
Authors: MUFF PATRICK , KROPF CHRISTIAN , FRICK HOLGER , NENTWIG WOLFGANG , SCHMIDT‐ENTLING MARTIN H.
Published: January 2009

Abstract. 

Habitat boundaries can contain high biodiversity because they potentially combine species from two habitat types plus additional boundary specialists. However, most research on animal communities is focused on uniform habitats.

Here, we assessed the degree to which the community change at a habitat edge is determined by the broad‐scale spatial transition from one habitat to the other, or by fine‐scale environmental influences. We compared the distribution of ground‐dwelling spider species from open land to forest with the distribution around stand‐alone trees at the boundary, the alpine timberline (Grisons, Switzerland).

Our results showed that spiders were more strongly influenced by local environmental conditions (40% of explained variation) than by the spatial position within the ecotone (24.5% of explained variation, with 15.6% overlap between the two). Spider communities differentiated according to light availability and corresponding changes in the ground vegetation.

Since the small area around a single tree at the studied timberline offered a similar broad spectrum of environmental conditions as the open land and forest together, it provided both habitats for species from the adjoining open land and forest as well as for some possible timberline specialists.

Accordingly, natural habitat boundaries may maintain very contrasting communities by providing a wide range of habitat conditions.
Cooperative conservation efforts to help recover an endangered south Florida butterfly
Authors: DANIELS JARET C.
Published: January 2009

Abstract. 

The Miami blue (Cyclargus thomasi bethunebakeri) (Lycaenidae) is a small, brightly coloured butterfly endemic to Florida.

It was once locally common across much of the south Florida mainland south through the Florida Keys to the Dry Tortugas.

Over the last few decades, ever‐expanding urbanisation and the associated loss of coastal habitat have lead to a significant reduction in the taxon's overall geographical distribution and numerical abundance.

The butterfly is currently limited to two small extant populations in the Lower Florida Keys, making it one of the most imperilled insects in North American and warranting a state of Florida listing as endangered.

As part of a large‐scale, model cooperative recovery programme led by the Florida Fish and Wildlife Conservation Commission, the University of Florida, the National Park Service, and the Florida Department of Environmental Protection, efforts are underway to conserve the butterfly through captive propagation, organism re‐introduction to state and federal lands, and research on the biology, population ecology, genetic diversity, and non‐target impact of mosquito control adulticides.
An empirical investigation of the welfare effects of banning wholesale price discrimination
Authors: Villas‐Boas Sofia Berto
Published: January 2009

Economic theory does not provide sharp predictions on the welfare effects of banning wholesale price discrimination: if downstream cost differences exist, then discrimination shifts production inefficiently, toward high‐cost retailers, so a ban increases welfare; if differences in price elasticity of demand across retailers exist, discrimination may increase welfare if quantity sold increases, so a ban reduces welfare. Using retail prices and quantities of coffee brands sold by German retailers, I estimate a model of demand and supply and separate cost and demand differences. Simulating a ban on wholesale price discrimination has positive welfare effects in this market, and less if downstream cost differences shrink, or with less competition.
Managerial hedging, equity ownership, and firm value
Authors: Acharya Viral V. , Bisin Alberto
Published: January 2009

Suppose risk‐averse managers can hedge the aggregate component of their exposure to firm's cash‐flow risk by trading in financial markets but cannot hedge their firm‐specific exposure. This gives them incentives to pass up firm‐specific projects in favor of standard projects that contain greater aggregate risk. Such forms of moral hazard give rise to excessive aggregate risk in stock markets. In this context, optimal managerial contracts induce a relationship between managerial ownership and (i) aggregate risk in the firm's cash flows, as well as (ii) firm value. We show that this can help explain the shape of the empirically documented relationship between ownership and firm performance.
Vertical restraints and horizontal control
Authors: Innes Robert , Hamilton Stephen F.
Published: January 2009

This article considers vertical restraints in a setting in which duopoly retailers each sell more than one manufactured good. Vertical restraints by a dominant manufacturer enable the firm to acquire horizontal control over a competitively supplied retail good. The equilibrium contracts produce symptoms that are consistent with a variety of observed retail practices, including slotting fees paid to retailers by competitive suppliers, loss leadership, and predatory accommodation with below‐cost manufacturer pricing for the dominant brand(s). Applications are developed for supermarket retailing, where the manufacturer of a national brand seeks to control the retail pricing of a supermarket's private label, and for convenience stores, where a gasoline provider seeks to control the retail pricing of an in‐store composite consumption good.
Optimal Estimation of Dynamically Consistent Kinematics and Kinetics for Forward Dynamic Simulation of Gait
Authors: Remy C. David , Thelen Darryl G.
Published: January 2009

Forward dynamic simulation provides a powerful framework for characterizing internal loads and for predicting changes in movement due to injury, impairment or surgical intervention. However, the computational challenge of generating simulations has greatly limited the use and application of forward dynamic models for simulating human gait. In this study, we introduce an optimal estimation approach to efficiently solve for generalized accelerations that satisfy the overall equations of motion and best agree with measured kinematics and ground reaction forces. The estimated accelerations are numerically integrated to enforce dynamic consistency over time, resulting in a forward dynamic simulation. Numerical optimization is then used to determine a set of initial generalized coordinates and speeds that produce a simulation that is most consistent with the measured motion over a full cycle of gait. The proposed method was evaluated with synthetically created kinematics and force plate data in which both random noise and bias errors were introduced. We also applied the method to experimental gait data collected from five young healthy adults walking at a preferred speed. We show that the proposed residual elimination algorithm (REA) converges to an accurate solution, reduces the detrimental effects of kinematic measurement errors on joint moments, and eliminates the need for residual forces that arise in standard inverse dynamics. The greatest improvements in joint kinetics were observed proximally, with the algorithm reducing joint moment errors due to marker noise by over 20% at the hip and over 50% at the low back. Simulated joint angles were generally within 1deg of recorded values when REA was used to generate a simulation from experimental gait data. REA can thus be used as a basis for generating accurate simulations of subject-specific gait dynamics.
The Structure of Rat Liver Vault at 3.5 Angstrom Resolution
Authors: Tanaka Hideaki , Kato Koji , Yamashita Eiki , Sumizawa Tomoyuki , Zhou Yong , Yao Min , Iwasaki Kenji , Yoshimura Masato , Tsukihara Tomitake
Published: January 2009

Vaults are among the largest cytoplasmic ribonucleoprotein particles and are found in numerous eukaryotic species. Roles in multidrug resistance and innate immunity have been suggested, but the cellular function remains unclear. We have determined the x-ray structure of rat liver vault at 3.5 angstrom resolution and show that the cage structure consists of a dimer of half-vaults, with each half-vault comprising 39 identical major vault protein (MVP) chains. Each MVP monomer folds into 12 domains: nine structural repeat domains, a shoulder domain, a cap-helix domain, and a cap-ring domain. Interactions between the 42-turn-long cap-helix domains are key to stabilizing the particle. The shoulder domain is structurally similar to a core domain of stomatin, a lipid-raft component in erythrocytes and epithelial cells.
Morphogenesis of Self-Assembled Nanocrystalline Materials of Barium Carbonate and Silica
Authors: García-Ruiz Juan Manuel , Melero-García Emilio , Hyde Stephen T.
Published: January 2009

The precipitation of barium or strontium carbonates in alkaline silica-rich environments leads to crystalline aggregates that have been named silica/carbonate biomorphs because their morphology resembles that of primitive organisms. These aggregates are self-assembled materials of purely inorganic origin, with an amorphous phase of silica intimately intertwined with a carbonate nanocrystalline phase. We propose a mechanism that explains all the morphologies described for biomorphs. Chemically coupled coprecipitation of carbonate and silica leads to fibrillation of the growing front and to laminar structures that experience curling at their growing rim. These curls propagate in a surflike way along the rim of the laminae. We show that all observed morphologies with smoothly varying positive or negative Gaussian curvatures can be explained by the combined growth of counterpropagating curls and growing laminae.
Recombination of Retrotransposon and Exogenous RNA Virus Results in Nonretroviral cDNA Integration
Authors: Geuking Markus B. , Weber Jacqueline , Dewannieux Marie , Gorelik Elieser , Heidmann Thierry , Hengartner Hans , Zinkernagel Rolf M. , Hangartner Lars
Published: January 2009

Retroviruses have the potential to acquire host cell–derived genetic material during reverse transcription and can integrate into the genomes of larger, more complex DNA viruses. In contrast, RNA viruses were believed not to integrate into the host's genome under any circumstances. We found that illegitimate recombination between an exogenous nonretroviral RNA virus, lymphocytic choriomeningitis virus, and the endogenous intracisternal A-type particle (IAP) retrotransposon occurred and led to reverse transcription of exogenous viral RNA. The resulting complementary DNA was integrated into the host's genome with an IAP element. Thus, RNA viruses should be closely scrutinized for any capacity to interact with endogenous retroviral elements before their approval for therapeutic use in humans.
Safety and Immunogenicity of the
Mycobacterium tuberculosis
Δ
lysA
Δ
panCD
Vaccine in Domestic Cats Infected with Feline Immunodeficiency Virus
Authors: Zimmerman Dawn M. , Waters W. Ray , Lyashchenko Konstantin P. , Nonnecke Brian J. , Armstrong Douglas L. , Jacobs William R. , Larsen Michelle H. , Egan Erin , Dean Gregg A.
Published: January 2009

Feline immunodeficiency virus (FIV)-positive and FIV-negative cats (
n
= 4/group) received 2 × 10
6
CFU
Mycobacterium tuberculosis
Δ
lysA
Δ
panCD
intramuscularly. Vaccination elicited antibody responses, albeit at lower levels in FIV-positive cats than in FIV-negative cats. Delayed-type hypersensitivity responses were minimal in both groups. No adverse reactions were found.
Improved Detection of
Histoplasma
Antigenemia following Dissociation of Immune Complexes
Authors: Swartzentruber S. , LeMonte A. , Witt J. , Fuller D. , Davis T. , Hage C. , Connolly P. , Durkin M. , Wheat L. J.
Published: January 2009

The sensitivity for detection of
Histoplasma
antigen is lower in serum than in urine. In other antigen assays, treatment of serum at 104°C in the presence of EDTA was required for detection of antigenemia. Sensitivity and specificity for detection of
Histoplasma
antigenemia were examined with or without EDTA heat treatment of the serum using the MVista
Histoplasma
antigen enzyme immunoassay. A total of 94.6% of serum specimens from patients with AIDS and histoplasmosis that were negative untreated were positive after EDTA-heat treatment. Two-thirds of the negative serum specimens from patients with probable histoplasmosis, based upon clinical suspicion and
Histoplasma
antigenuria, were positive after heat treatment. Specificity was 99.0% in controls, including healthy subjects and patients in whom histoplasmosis or blastomycosis, were excluded. Precision and reproducibility were good and excellent, respectively. These findings demonstrate improvement in sensitivity without reduction in specificity, precision, or reproducibility after heat-EDTA treatment.
Campylobacter fetus
-Associated Epidural Abscess and Bacteremia
Authors: Wong Jenny S. J. , Anderson Trevor P. , Chambers Stephen T. , On Stephen L. W. , Murdoch David R.
Published: January 2009

Campylobacter fetus
has been isolated as an infrequent cause of abscesses. We report a case of
Campylobacter fetus
epidural abscess and bacteremia in a debilitated elderly man who had a fatal outcome.
Changes in Vaginal Bacterial Concentrations with Intravaginal Metronidazole Therapy for Bacterial Vaginosis as Assessed by Quantitative PCR
Authors: Fredricks David N. , Fiedler Tina L. , Thomas Katherine K. , Mitchell Caroline M. , Marrazzo Jeanne M.
Published: January 2009

Several fastidious bacteria have been associated with bacterial vaginosis (BV) using broad-range bacterial PCR methods such as consensus sequence 16S rRNA gene PCR, but their role in BV remains poorly defined. We describe changes in vaginal bacterial concentrations following metronidazole therapy for BV. Vaginal swabs were collected from women with BV diagnosed using Amsel clinical criteria, and vaginal fluid was assessed by Gram stain to generate Nugent scores. Follow-up swabs were collected 1 month after a 5-day course of vaginal 0.75% metronidazole gel and analyzed for 24 subjects with cured BV and 24 subjects with persistent BV. Changes in bacterial concentrations were measured using eight bacterium-specific 16S rRNA gene quantitative PCR assays. DNA from several fastidious BV-associated bacteria (BVAB) were present at high concentrations in the vagina prior to treatment. Successful antibiotic therapy resulted in 3- to 4-log reductions in median bacterial loads of BVAB1 (
P
= 0.02), BVAB2 (
P
= 0.0004), BVAB3 (
P
= 0.03), a
Megasphaera
-like bacterium (
P
< 0.0001),
Atopobium
species (
P
< 0.0001),
Leptotrichia
/
Sneathia
species (
P
= 0.0002), and
Gardnerella vaginalis
(
P
< 0.0001). Median posttreatment bacterial levels did not change significantly in subjects with persistent BV except for a decline in levels of BVAB3. The presence or absence of BV is reflected by vaginal concentrations of BV-associated bacteria such as BVAB1, BVAB2,
Leptotrichia/Sneathia
species,
Atopobium
species,
Gardnerella vaginalis
, and a
Megasphaera
-like bacterium, suggesting that these bacteria play an important role in BV pathogenesis and may be suitable markers of disease and treatment response.
Interpretation of MRSA
Select
Screening Agar at 24 Hours of Incubation
Authors: Carson Julie , Lui Betty , Rosmus Linda , Rennick Howard , Fuller Jeff
Published: January 2009

An incubation time of 24 h at 35 to 38°C is recommended for the optimal performance of MRSA
Select
(Bio-Rad) chromogenic screening agar. An additional 24 h is required to capture slow-growing methicillin-resistant
Staphylococcus aureus
(MRSA). However, the normal hours of operation for most laboratories cannot reliably accommodate 24-h interpretation intervals. Daily agar plate interpretations are more likely to occur around 18 h and 42 h of incubation, which may compromise the performance of the chromogenic agar and negatively impact patient infection control efforts. In order to validate the importance of stringent incubation times to plate performance, we evaluated MRSA
Select
medium at controlled intervals of 24 and 48 h of incubation, using clinical MRSA-screening swabs. A total of 1,071 MRSA-positive and 2,733 MRSA-negative cultures were selected for analysis. Compared to 48-h-incubation results, the sensitivity and specificity of MRSA
Select
at 24 h were 98.3% and 98.2%, respectively. Only 19 of 1,071 (1.8%) MRSA-positive isolates required 48 h for detection. Holding 24-h negative plates an additional 24 h resulted in the workup of 253 (6.6%) pink, yet non-MRSA, colonies. The 24-h positive and negative predictive values of MRSA
Select
, assuming MRSA prevalences of 1, 5, and 10%, were 35.5 and 99.98%, 74.2 and 99.9%, and 85.9 and 99.8%, respectively. MRSA
Select
medium held for 24-h incubation is a highly sensitive and specific MRSA-screening tool. Further incubation prolongs the turnaround time for results and creates a significant amount of unnecessary work in the laboratory.
Genetic Heterogeneity among Strains ofTreponema phagedenis-Like Spirochetes Isolated from Dairy Cattle with Papillomatous Digital Dermatitis in Japan
Authors: Yano Takahisa , Yamagami Ryoko , Misumi Kazuhiro , Kubota Chikara , Moe Kyaw Kyaw , Hayashi Tetsuya , Yoshitani Kazunori , Ohtake Osamu , Misawa Naoaki
Published: January 2009

Papillomatous digital dermatitis (PDD) is an infectious foot disease of cattle that is prevalent throughout the world. Although it has been prevalent in Japan since the first case was reported in 1992, full epidemiological and bacteriological examinations have not been conducted. We collected 91 lesions of PDD from 80 dairy cattle on 12 farms in eight regions of Japan to isolate the spirochetes that are frequently detected in lesions. We isolated 40 strains of spirochetes from 24 cattle (30.0%) by a simple two-step culture technique, in which the biopsy samples were incubated at 4°C for 48 to 72 h in an enrichment broth supplemented with antibiotics, which improved the rate of isolation, and then inoculated on selective agar plates. All spirochetes examined were catalase positive and oxidase negative and showed weak beta-hemolytic activity. Enzyme activities were identical to those ofTreponema phagedenisATCC 27087. Sequencing of the 16S rRNA gene showed that all strains isolated had >99% identity to those of theT. phagedenistype strain and ofT. phagedenis-like strains isolated from PDD lesions in the United States and Europe. Pulsed-field gel electrophoresis and PCR-based random amplified polymorphism DNA methods revealed considerable diversity among strains isolated not only from different cattle but also from the same individuals. These findings may provide further evidence for the role of these treponemes in the pathogenesis of persistent PDD.
Characterization of Large Mumps Outbreak among Vaccinated Palestinian Refugees
Authors: Hindiyeh Musa Y. , Aboudy Yair , Wohoush Mahmoud , Shulman Lester M. , Ram Daniela , Levin Tal , Frank Tamar , Riccardo Flavia , Khalili Mohamad , Sawalha Elias-Shlash , Obeidi Maysoun , Sabatinelli Guido , Grossman Zehava , Mendelson Ella
Published: January 2009

During a large mumps virus (MuV) outbreak which occurred in the Palestinian refugee camps of the West Bank, 68.1% (2,636/3,871) of the cases were vaccinated with one dose of trivalent measles, mumps, and rubella (MMR) vaccine. Attack rates by camp ranged from less than 1 case per 1,000 people in the population to 43/1,000 (overall, 11/1,000). The outbreak lasted from December 2003 to June 2005, with two peaks, one from April to May 2004 and the other from March to April 2005. To control the outbreak, a mass MMR vaccination campaign was conducted in May 2005. Evaluation of the immune status of cases (
n
= 59) and healthy controls (
n
= 51) revealed high levels of mumps immunoglobulin G (IgG) and a low MuV-specific IgM in clinical cases indicative of a booster immune response. This suggested a secondary rather than a primary infection due to the insufficient protection conferred by the single vaccine dose included in the vaccination program. This prediction was further confirmed by the low seroprevalence (68.6%) found in the healthy control group, which was below the threshold level required for MuV herd immunity. Mumps diagnosis was established mainly by reverse transcription-PCR in clinical samples obtained within 48 h from the onset of disease. Of the parotid fluids and nasopharyngeal aspirates analyzed, 92% were positive for MuV RNA, while only 33% of the urine samples were positive. Phylogenetic analysis of the MuV SH gene identified the outbreak strain as the H genotype, which has been in circulation worldwide at least since 1989.
Rapid Detection of
Staphylococcus aureus
and Methicillin-Resistant
S. aureus
(MRSA) in Wound Specimens and Blood Cultures: Multicenter Preclinical Evaluation of the Cepheid Xpert MRSA/SA Skin and Soft Tissue and Blood Culture Assays
Authors: Wolk D. M. , Struelens M. J. , Pancholi P. , Davis T. , Della-Latta P. , Fuller D. , Picton E. , Dickenson R. , Denis O. , Johnson D. , Chapin K.
Published: January 2009

A multicenter preclinical evaluation was conducted to evaluate the performance of two Cepheid Xpert assays for detection of methicillin-resistant
Staphylococcus aureus
(MRSA) and
S. aureus
. Sensitivity was 97.1% and 98.3% for MRSA in wound and blood culture specimens, respectively. Sensitivity was 100% for
S. aureus
from both specimen types.