bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lgals6, a 2-Million-Year-Old Gene in Mice: A Case of Positive Darwinian Selection and Presence/Absence Polymorphism
Authors: Houzelstein Denis , Gonçalves Isabelle R , Orth Annie , Bonhomme François , Netter Pierre 
Published: April 2008

Abstract
Duplications of genes are widely considered to be a driving force in the evolutionary process. The fate of such duplicated genes (paralogs) depends mainly on the early stages of their evolution. Therefore, the study of duplications that have already started to diverge is useful to better understand their evolution. We present here the example of a 2-million-year-old segmental duplication at the origin of the Lgals4 and Lgals6 genes in the mouse genome. We analyzed the distribution of these genes in samples from 110 wild individuals and wild-derived inbred strains belonging to eight mouse species from Mus (Coelomys) pahari to M. musculus and 28 laboratory strains. Using a maximum-likelihood method, we show that the sequence of the Lgals6 gene has evolved under the influence of strong positive selection that is likely to result in its neofunctionalization. Surprisingly, despite this selection pressure, the Lgals6 gene is present in some mouse species, but not all. Furthermore, even within the species and populations where it is present, the Lgals6 gene is never fixed. To explain this paradox, we propose different hypotheses such as balanced selection and neutral retention of ancient polymophism and we discuss this unexpected result with regard to known galectin properties and response to infections by pathogens.
A Suppressor Screen in Chlamydomonas Identifies Novel Components of the Retinoblastoma Tumor Suppressor Pathway
Authors: Fang Su-Chiung , Umen James G 
Published: April 2008

Abstract
The retinoblastoma (RB) protein is a eukaryotic tumor suppressor and negative cell-cycle regulator. Chlamydomonas reinhardtii cells that lack the RB homolog MAT3 show loss of size checkpoint control and deregulated cell-cycle progression leading to the production of tiny cells. We carried out an insertional mutagenesis screen to isolate bypass suppressors of mat3 (smt mutants) that reverted the mat3 cell-size defect. Previously we reported that the loci encoding Chlamydomonas homologs of E2F and DP were frequently disrupted in this screen, indicating that the architecture of the canonical RB pathway is conserved in Chlamydomonas with MAT3/RB acting as a negative regulator upstream of E2F/DP. Here, we describe four novel smt mutants that moderately suppressed the cell-size checkpoint and cell-cycle phenotypes of mat3. As single mutants, three of the smt strains displayed no obvious phenotypes, and one had a slightly small phenotype. Strikingly, several smt double-mutant combinations synergized to cause enhanced suppression of mat3 and even to cause a large-cell phenotype that is comparable to that caused by loss of DP1. Molecular characterization of one smt mutant revealed that suppression is due to a defect in a gene encoding a putative small ubiquitin-like modifier (SUMO) peptidase. Our results reveal a complex genetic network that lies downstream of MAT3/RB and implicate protein sumoylation as an important step for cell-cycle progression in cells that are missing MAT3/RB.
Probing the Relative Importance of Molecular Oscillations in the Circadian Clock
Authors: Zheng Xiangzhong , Sehgal Amita 
Published: April 2008

Abstract
Circadian (∼24 hr) rhythms of behavior and physiology are driven by molecular clocks that are endogenous to most organisms. The mechanisms underlying these clocks are remarkably conserved across evolution and typically consist of auto-regulatory loops in which specific proteins (clock proteins) rhythmically repress expression of their own genes. Such regulation maintains 24-hr cycles of RNA and protein expression. Despite the conservation of these mechanisms, however, questions are now being raised about the relevance of different molecular oscillations. Indeed, several studies have demonstrated that oscillations of some critical clock genes can be eliminated without loss of basic clock function. Here, we describe the multiple levels at which clock gene/protein expression and function can be rhythmically regulated—transcription, protein expression, post-translational modification, and localization—and speculate as to which aspect of this regulation is most critical. While the review is focused on Drosophila, we include some discussion of mammalian clocks to indicate the extent to which the questions concerning clock mechanisms are similar, regardless of the organism under study.
Effect of soil sorption and aquatic natural organic matter on the antibacterial activity of a fullerene water suspension
Authors: Li Dong , Lyon Delina Y , Li Qilin , Alvarez Pedro J. J 
Published: April 2008

Abstract
The present study investigated the association of a C60 water suspension (nC60) with natural organic matter, present as a soil constituent or dissolved in the water column, and its effect on the antibacterial activity of nC60. Sorption of nC60 to soil reduced its bioavailability and antibacterial activity, and the sorption capacity strongly depended on the organic content of the soil. Adsorption of aquatic dissolved humic substances onto nC60 and possible subsequent reactions also were found to eliminate nC60 toxicity at humic acid concentrations as low as 0.05 mg/L. These findings indicate that natural organic matter in the environment can mitigate significantly the potential impacts of nC60 on microbial activities that are important to ecosystem health.
Estimation of the soil–water partition coefficient normalized to organic carbon for ionizable organic chemicals
Authors: Franco Antonio , Trapp Stefan 
Published: April 2008

Abstract
The sorption of organic electrolytes to soil was investigated. A dataset consisting of 164 electrolytes, composed of 93 acids, 65 bases, and six amphoters, was collected from literature and databases. The partition coefficient log KOW of the neutral molecule and the dissociation constant pKa were calculated by the software ACD/Labs®. The Henderson-Hasselbalch equation was applied to calculate dissociation. Regressions were developed to predict separately for the neutral and the ionic molecule species the distribution coefficient (Kd) normalized to organic carbon (KOC) from log KOW and pKa. The log KOC of strong acids (pKa &lt; 4) was not correlated to these parameters. The regressions derived for weak acids and bases (undissociated at environmental pH) were similar. The highest sorption was found for strong bases (pKa &gt; 7.5), probably due to electrical interactions. Nonetheless, their log KOC was highly correlated to log KOW. For bases, a nonlinear regression was developed, too. The new regression equations are applicable in the whole pKa range of acids, bases, and amphoters and are useful in particular for relatively strong bases and amphoters, for which no predictive methods specifically have been developed so far.
Effects of ingested nano-sized titanium dioxide on terrestrial isopods (Porcellio scaber)
Authors: Jemec Anita , Drobne Damjana , Remškar Maja , Sepčić Kristina , Tišler Tatjana 
Published: April 2008

Abstract
The effects of ingested nano-sized titanium dioxide (TiO2; anatase, 15 nm) on the terrestrial isopod Porcellio scaber (Isopoda, Crustacea) after short-term (3-d) dietary exposure were studied. Activities of antioxidant enzymes, such as catalase (CAT) and glutathione-S-transferase (GST), in digestive glands were affected in a dose-independent manner, but higher-level isopod endpoints, including weight change, feeding rate, food assimilation efficiency, and survival, were not affected up to the highest tested concentration of TiO2 in food (3,000 μg/g). Exposure concentrations of 0.5, 2,000, and 3,000 μg nonsonicated TiO2/g food decreased CAT and GST activities, but intermediate concentrations (1, 10, 100, and 1,000 μg/g food) did not result in significant changes of enzyme activities. When the dispersion of TiO2 was sonicated, no effects on enzyme activities or higher-level biomarkers were observed. The experimental setup with terrestrial isopods designed for dissolved chemicals also is suitable for testing the effects of ingested nanoparticles, but the presentation of toxicity data needs to be adapted according to the mode of action of the nanoparticles and their specific characteristics.
Communicating With the Public About Emerging Health Threats: Lessons From the Pre-Event Message Development Project
Authors: Wray Ricardo J. , Becker Steven M. , Henderson Neil , Glik Deborah , Jupka Keri , Middleton Sarah , Henderson Carson , Drury Allison , Mitchell Elizabeth W. 
Published: April 2008

Objectives. We sought to better understand the challenges of communicating with the public about emerging health threats, particularly threats involving toxic chemicals, biological agents, and radioactive materials.Methods. At the request of the Centers for Disease Control and Prevention, we formed an interdisciplinary consortium of investigative teams from 4 schools of public health. Over 2 years, the investigative teams conducted 79 focus group interviews with 884 participants and individual cognitive response interviews with 129 respondents, for a total sample of 1013 individuals. The investigative teams systematically compared their results with other published research in public health, risk communication, and emergency preparedness.Results. We found limited public understanding of emerging biological, chemical, and radioactive materials threats and of the differences between them; demand for concrete, accurate, and consistent information about actions needed for protection of self and family; active information seeking from media, local authorities, and selected national sources; and areas in which current emergency messaging can be improved.Conclusions. The public will respond to a threat situation by seeking protective information and taking self-protective action, underlining the critical role of effective communication in public health emergencies.
Effects of Enrollment in Medicaid Versus the State Children’s Health Insurance Program on Kindergarten Children’s Untreated Dental Caries
Authors: Brickhouse Tegwyn H. , Rozier R. Gary , Slade Gary D. 
Published: April 2008

Objectives. We compared levels of untreated dental caries in children enrolled in public insurance programs with those in nonenrolled children to determine the impact of public dental insurance and the type of plan (Medicaid vs State Children’s Health Insurance Program [SCHIP]) on untreated dental caries in children. Methods. Dental health outcomes were obtained through a calibrated oral screening of kindergarten children (enrolled in the 2000–2001 school year). We obtained eligibility and claims data for children enrolled in Medicaid and SCHIP who were eligible for dental services during 1999 to 2000. We developed logistic regression models to compare children’s likelihood and extent of untreated dental caries according to enrollment. Results. Children enrolled in Medicaid or SCHIP were 1.7 times (95% confidence interval [CI] = 1.65, 1.77) more likely to have untreated dental caries than were nonenrolled children. SCHIP-enrolled children were significantly less likely to have untreated dental caries than were Medicaid-enrolled children (odds ratio [OR]=0.74; 95% CI=0.67, 0.82). According to a 2-part regression model, children enrolled in Medicaid or SCHIP have 17% more untreated dental caries than do nonenrolled children, whereas those in SCHIP had 16% fewer untreated dental caries than did those in Medicaid. Conclusions. Untreated tooth decay continues to be a significant problem for children with public insurance coverage. Children who participated in a separate SCHIP program had fewer untreated dental caries than did children enrolled in Medicaid.
Bioterrorism Surveillance and Privacy: Intersection of HIPAA, the Common Rule, and Public Health Law
Authors: Nordin James D. , Kasimow Sophie , Levitt Mary Jeanne , Goodman Michael J. 
Published: April 2008

The threat of bioterrorism in the wake of the September 11, 2001, terrorist attacks cannot be ignored. Syndromic surveillance, the practice of electronically monitoring and reporting real-time medical data to proactively identify unusual disease patterns, highlights the conflict between safeguarding public health while protecting individual privacy.Both the Health Insurance Portability and Accountability Act and the Common Rule (which promulgates protections for individuals in federally sponsored medical research programs) safeguard individuals. Public health law protects the entire populace; uneven state-level implementation lacks adequate privacy protections.We propose 3 models for a nationwide bioterrorism surveillance review process: a nationally coordinated systems approach to using protected health information, creating public health information privacy boards, expanding institutional review boards, or some combination of these.
A Randomized Intervention Trial to Reduce the Lending of Used Injection Equipment Among Injection Drug Users Infected With Hepatitis C
Authors: Latka Mary H. , Hagan Holly , Kapadia Farzana , Golub Elizabeth T. , Bonner Sebastian , Campbell Jennifer V. , Coady Micaela H. , Garfein Richard S. , Pu Minya , Thomas Dave L. , Thiel Thelma K. , Strathdee Steffanie A. 
Published: April 2008

Objectives. We evaluated the efficacy of a peer-mentoring behavioral intervention designed to reduce risky distributive injection practices (e.g., syringe lending, unsafe drug preparation) among injection drug users with hepatitis C virus (HCV) infection. Methods. A randomized trial with a time-equivalent attention-control group was conducted among 418 HCV-positive injection drug users aged 18 to 35 years in 3 US cities. Participants reported their injection-related behaviors at baseline and at 3- and 6-month follow-ups. Results. Compared with the control group, intervention-group participants were less likely to report distributive risk behaviors at 3 months (odds ratio [OR]=0.46; 95% confidence interval [CI]=0.27, 0.79) and 6 months (OR=0.51; 95% CI=0.31, 0.83), a 26% relative risk reduction, but were no more likely to cite their HCV-positive status as a reason for refraining from syringe lending. Effects were strongest among intervention-group participants who had known their HCV-positive status for at least 6 months. Peer mentoring and self-efficacy were significantly increased among intervention-group participants, and intervention effects were mediated through improved self-efficacy. Conclusions. This behavioral intervention reduced unsafe injection practices that may propagate HCV among injection drug users.
The Relationship Between In-Home Water Service and the Risk of Respiratory Tract, Skin, and Gastrointestinal Tract Infections Among Rural Alaska Natives
Authors: Hennessy Thomas W. , Ritter Troy , Holman Robert C. , Bruden Dana L. , Yorita Krista L. , Bulkow Lisa , Cheek James E. , Singleton Rosalyn J. , Smith Jeff 
Published: April 2008

Objectives. We investigated the relationship between the presence of in-home piped water and wastewater services and hospitalization rates for respiratory tract, skin, and gastrointestinal tract infections in rural Alaska. Methods. We determined in-home water service and hospitalizations for selected infectious diseases among Alaska Natives by region during 2000 to 2004. Within 1 region, infant respiratory hospitalizations and skin infections for all ages were compared by village-level water services. Results. Regions with a lower proportion of home water service had significantly higher hospitalization rates for pneumonia and influenza (rate ratio [RR] = 2.5), skin or soft tissue infection (RR = 1.9), and respiratory syncytial virus (RR = 3.4 among those younger than 5 years) than did higher-service regions. Within 1 region, infants from villages with less than 10% of homes served had higher hospitalization rates for pneumonia (RR = 1.3) and respiratory syncytial virus (RR = 1.2) than did infants from villages with more than 80% served. Outpatient Staphylococcus aureus infections (RR = 5.1, all ages) and skin infection hospitalizations (RR = 2.7, all ages) were higher in low-service than in high-service villages. Conclusions. Higher respiratory and skin infection rates were associated with a lack of in-home water service. This disparity should be addressed through sanitation infrastructure improvements.
Population Attributable Fractions of Psychiatric Disorders and Suicide Ideation and Attempts Associated With Adverse Childhood Experiences
Authors: Afifi Tracie O. , Enns Murray W. , Cox Brian J. , Asmundson Gordon J.G. , Stein Murray B. , Sareen Jitender 
Published: April 2008

Objectives. We sought to determine the fractions of psychiatric disorders and suicide ideation and attempts in a general population sample attributable to childhood physical abuse, sexual abuse, and witnessing domestic violence. Methods. Data were obtained from the US National Comorbidity Survey Replication. Population attributable fractions were calculated to determine the proportion of psychiatric disorders and suicide ideation and attempts attributable to adverse childhood experiences. The analysis was stratified by gender. Results. The estimated attributable fractions for psychiatric disorders attributable to having experienced any adverse childhood event ranged from 22% to 32% among women and 20% to 24% among men. Having experienced any adverse event accounted for a substantial proportion of suicide ideation and attempts among women (16% and 50%, respectively) and men (21% and 33%, respectively). Substantial proportions of poor mental health outcomes were also attributable to increasing number of adverse events. Conclusions. The estimated proportions of poor mental health outcomes attributed to childhood adversity were medium to large for men and women. Prevention efforts that reduce exposure to adverse childhood events could substantially reduce the prevalence of psychopathology and suicidal behavior in the general population.
Intervening to Reduce Inequalities in Infections in Europe
Authors: Semenza Jan C. , Giesecke Johan 
Published: April 2008

The European Centre for Disease Prevention and Control was founded in response to newly emerging infections such as severe acute respiratory syndrome and avian influenza. However, Europe faces other communicable disease challenges that have proven to be remarkably resilient to public health interventions. We present examples of communicable diseases with inequitable distribution among those with poor educational attainment, low income, or other socioeconomic factors in every European country. Because these findings are incompatible with social justice and fairness, we examine strategic interventions targeting upstream causes of communicable disease transmission keeping in mind 10 indispensable public health functions essential to reach marginalized groups. These interventions have to be tailored to the socio-political context and rely on community-based decision-making and intersectorial collaboration.
Characteristics of Physically Active Smokers and Implications for Harm Reduction
Authors: deRuiter Wayne K. , Faulkner Guy , Cairney John , Veldhuizen Scott 
Published: April 2008

Objectives. We sought to establish the prevalence of physical activity among smokers, whether or not physically active smokers were more likely to attempt cessation, and who these physically active smokers were. Methods. We used logistic regression to contrast physically active and inactive smokers in a secondary data analysis of the Canadian Community Health Survey Cycle 1.1. Results. Physically active smokers represented almost one quarter of the smoking population. Compared with physically inactive smokers, physically active smokers were more likely to have attempted cessation in the past year. Physically active smokers were more likely to be young, single, and men compared with their inactive counterparts. Income had no influence in distinguishing physically active and inactive smokers. Conclusions. Skepticism persists regarding the practicality and potential risks of promoting physical activity as a harm-reduction strategy for tobacco use. We found that a modest proportion of the daily smoking population was physically active and that engagement in this behavior was related to greater cessation attempts. Interventions could be developed that target smokers who are likely to adopt physical activity.
Exact solutions of the D-dimensional Schrödinger equation for a ring-shaped pseudoharmonic potential
Authors: Ikhdair Sameer , Sever Ramazan 
Published: April 2008

Abstract
A new non-central potential, consisting of a pseudoharmonic potential plus another recently proposed ring-shaped potential, is solved. It has the form $$
V(r,\theta ) = \tfrac{1}
{8}\kappa r_e^2 \left( {\tfrac{r}
{{r_e }} - \tfrac{{r_e }}
{r}} \right)^2 + \tfrac{{\beta cos^2 \theta }}
{{r^2 sin^2 \theta }}
$$. The energy eigenvalues and eigenfunctions of the bound-states for the Schrödinger equation in D-dimensions for this potential are obtained analytically by using the Nikiforov-Uvarov method. The radial and angular parts of the wave functions are obtained in terms of orthogonal Laguerre and Jacobi polynomials. We also find that the energy of the particle and the wave functions reduce to the energy and the wave functions of the bound-states in three dimensions.
On solutions of the Schrödinger equation for some molecular potentials: wave function ansatz
Authors: Ikhdair Sameer , Sever Ramazan 
Published: April 2008

Abstract
Making an ansatz to the wave function, the exact solutions of the D-dimensional radial Schrödinger equation with some molecular potentials, such as pseudoharmonic and modified Kratzer, are obtained. Restrictions on the parameters of the given potential, δ and ν are also given, where η depends on a linear combination of the angular momentum quantum number ℓ and the spatial dimensions D and δ is a parameter in the ansatz to the wave function. On inserting D = 3, we find that the bound state eigensolutions recover their standard analytical forms in literature.
Anti-control of chaos in Bose-Einstein condensates
Authors: Wang Zhixia , Shen Ke 
Published: April 2008

Abstract
The spatial structure of a Bose-Einstein Condensate (BEC) loaded into an optical lattice potential is investigated. We suggest a method for generating chaos in BEC by modulating periodic signals to convert the regular states into chaotic states. The maximal Lyapunov exponent is calculated as a function of modulation intensity and modulation frequency respectively, and the chaotic orbits associated with the positive Lyapunov exponents.
Scanning tunneling spectrosopy study of DNA conductivity
Authors: Kratochvílová Irena , Král Karel , Bunček Martin , Nešpůorek Stanislav , Todorciuc Tatiana , Weiter Martin , Navrátil Jiři , Schneider Bohdan , Pavluch Jiři 
Published: April 2008

Abstract
We used STM to study the conductivity of 32 nucleotide long DNA molecules chemically attached to a gold surface. Two oligonucleotides containing all four base types namely G, A, C, T, one single stranded and one double helical, all showed conductance data significantly higher than DNA containing only T and A that were either single stranded d(T32) or double helical d(T32).d(A32) in confirmation. Within each sequence group, the conductivity of the double helical form was always higher than that of the single strand. We discuss the impact of structure, particular base stacking and affinity to the phase transition.