bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of Bt cry1Ac in transgenic oilseed rape in China and transgenic performance of intraspecific hybrids against Helicoverpa armigera larvae
Authors: Le Yin‐Ting , Stewart C.N. , Shi Hong , Wei Wei , Mi Xiang‐Cheng , Ma Ke‐Ping
Published: March 2007

The expression of a synthetic Bacillus thuringiensis (Bt) cry1Ac gene in oilseed rape (OSR, Brassica napus) was monitored under field conditions in China, and performance against Helicoverpa armigera larvae was compared in intraspecific hybrids with a Chinese OSR variety. Leaf samples from transgenic OSR were collected at various developmental stages in two separate field experiments. The Bt Cry1Ac concentrations in the third uppermost leaves increased before pod formation stage and either increased or decreased after pod formation stage whereas the total soluble protein increased before and decreased after pod‐fill in the later growing season. Spontaneously formed intraspecific hybrids between transgenic OSR and a Chinese conventional OSR were obtained in the field and transgenic status was confirmed by a green fluorescent protein (GFP) phenotype and polymerase chain reaction. A bioassay on the neonate larvae of a susceptible strain of H. armigera was performed to test the efficacy of Bt Cry1Ac toxin in hybrid OSR plants. Both the original transgenic OSR and hybrid plants had a negative effect on body‐weight gain of insect larvae. It was assumed that Bt Cry1Ac toxin concentration was similar in hybrids compared to the original transgenic OSR at the investigated developmental stages. The frequency of hybrid production and volunteerism could potentially enhance the evolution of insect pest tolerance in the field.
EXPANDING CRIMINOLOGY'S DOMAIN: THE AMERICAN SOCIETY OF CRIMINOLOGY 2006 PRESIDENTIAL ADDRESS*
Authors: LAFREE GARY
Published: March 2007

Democracy is directly linked to the two main components of criminology: crime and justice. Moreover, the scientific study of crime and justice has been limited in large part to researchers working in democratic regimes. In this article, I address the question of how criminologists through research and education can better nurture democratic, nonauthoritarian societies. I argue that our field would be strengthened by expanding the domain of criminology in five directions: 1) by providing more emphasis on historical data and analysis, 2) by broadening the scope of emotions we test for among offenders, 3) by doing more cross‐national comparative analysis, 4) by bringing situational variables into our research, and 5) by making criminology more interdisciplinary. Although the most recent wave of democratization produced a record number of democratic regimes, we are observing ominous challenges to fundamental democratic rights from around the world. As criminologists, we have a vested interest in supporting the democratic, nonauthoritarian societies in which our craft has thrived.
UNPACKING THE RELATIONSHIP BETWEEN ADOLESCENT EMPLOYMENT AND ANTISOCIAL BEHAVIOR: A MATCHED SAMPLES COMPARISON*
Authors: APEL ROBERT , BUSHWAY SHAWN , BRAME ROBERT , HAVILAND AMELIA M. , NAGIN DANIEL S. , PATERNOSTER RAY
Published: March 2007

A large body of research has consistently found that intensive employment during the school year is associated with heightened antisocial behavior. These findings have been influential in prompting policy recommendations to establish stricter limits on the number of hours that students can work during the school year. We reexamine the linkage between first‐time work at age 16 during the school year and problem behaviors. Our analysis uses group‐based trajectory modeling to stratify youths based on their developmental history of crime and substance abuse. This stratification serves to control for preexisting differences between workers and nonworkers and permits us to examine whether the effect of work on problem behaviors depends on the developmental history of those behaviors. Contrary to most prior research we find no overall effect of working on either criminal behavior or substance abuse. However, we do find some indication that work may have a salutary effect on these behaviors for some individuals who had followed trajectories of heightened criminal activity or substance abuse prior to their working for the first time.
DIRECTLY INTERVENE OR CALL THE AUTHORITIES? A STUDY OF FORMS OF NEIGHBORHOOD SOCIAL CONTROL WITHIN A SOCIAL DISORGANIZATION FRAMEWORK*
Authors: WARNER BARBARA D.
Published: March 2007

Informal social control is a central concept in the contemporary social disorganization literature, and much attention has been directed at examining community characteristics related to variation in the quantity of informal social control across communities. However, considerably less attention has been paid to variation in forms of informal social control. This study examines the extent to which neighborhood characteristics are related to residents’likelihood of using two different forms of informal social control: direct informal social control (i.e., through direct intervention) and indirect informal social control (i.e., through mobilizing formal authorities). Data for this study are based on surveys of residents in 66 neighborhoods. The analysis uses hierarchical modeling to examine whether neighborhood characteristics central to contemporary social disorganization theory have similar effects on these two forms of neighborhood social control. Findings indicate that social ties increase the likelihood of direct informal social control but not indirect informal social control, whereas social cohesion and trust decreases indirect informal social control but does not have a significant effect on direct informal social control. Faith in the police is not found to affect either form of informal social control. These findings are discussed in terms of current issues in contemporary social disorganization theory.
COPS GRANTS AND CRIME REVISITED*
Authors: WORRALL JOHN L. , KOVANDZIC TOMISLAV V.
Published: March 2007

Using 6 years of panel data, Zhao, Scheider, and Thurman (2002) found that funding from the U.S. Department of Justice, Office of Community Oriented Policing Services (COPS), reduced property and violent crime in large U.S. cities. We merged their COPS data with 11 years of panel data from a sample of 189 large cities, such that the period before the COPS program was covered. We also controlled for pre‐existing effects on crime of police spending. Finally, we performed various robustness checks and explored state‐specific effects of COPS spending. Our findings suggest that COPS spending had little to no effect on crime.
The effect of a topical anaesthetic formulation, systemic flunixin and carprofen, singly or in combination, on cortisol and behavioural responses of Merino lambs to mulesing
Authors: Paull DR , Lee C , Colditz IG , Atkinson SJ , Fisher AD
Published: March 2007

Objective  To determine the pain responses of lambs to mulesing, and the effectiveness of potential analgesic treatments.

Procedures  Merino lambs (n = 64) were allocated at 5 weeks of age to eight treatment groups: 1) sham mules; 2) conventional mules; 3) topical anaesthetic, incorporating lignocaine, bupivicaine, adrenaline and cetrimide, applied immediately after mulesing; 4) flunixin + topical anaesthetic, with flunixin administered 2.5 mg/kg s.c. 90 min before mulesing; 5) carprofen + topical anaesthetic, with carprofen administered 4 mg/kg s.c. 90 min before mulesing; 6) carprofen, administered as above; 7) flunixin, administered as above; and 8) carprofen + flunixin, administered as above. Plasma cortisol was measured at 0, 0.5, 6, 12 and 24 h relative to mulesing. Animal behaviour, including posture, was recorded for 12 h after mulesing.

Results  The conventional mules lambs exhibited large increases in plasma cortisol, reduced lying and increased standing with a hunched back compared with sham mules animals. Topical anaesthetic reduced the cortisol peak to mulesing and hunched standing, and increased lying compared with the conventional mules treatment, but generally did not result in values equivalent to sham mules animals. Carprofen, flunixin, and carprofen + flunixin treatments did not reduce the cortisol response to mulesing but substantially ameliorated some changes in behavioural postures. Flunixin + topical anaesthetic reduced the cortisol peak following mulesing and substantially ameliorated most changes in behavioural postures. Carprofen + topical anaesthetic abolished the cortisol peak following mulesing and substantially ameliorated most changes in behavioural postures. All mulesed animals lost weight in the week after mulesing regardless of analgesic administration, but there were no significant differences in growth rate between any of the eight treatments over the 3 weeks after mulesing.

Conclusions  Analgesics can moderate the pain response of lambs to mulesing. The welfare outcome for lambs of mulesing could be improved by use of a combination of local anaesthetic and long acting non‐steroidal anti‐inflammatory drug.
Prevalence of Dental Anxiety among 5‐ to 8‐Year‐Old Taiwanese Children
Authors: Lee Chen‐Yi , Chang Yong‐Yuan , Huang Shun‐Te
Published: March 2007

Objectives: Many people experience discomfort to a greater or lesser degree about the prospect of dental treatment. Dental treatment can be a terrible experience, especially for children with dental anxiety. This study estimated the prevalence of dental anxiety among 5‐ to 8‐year‐old children in Kaohsiung City, Taiwan.

Methods: The Children’s Fear Survey Schedule‐Dental Subscale (CFSS‐DS) was translated into Chinese, and a receiver operating characteristic (ROC) curve was made based on criteria determined from pretest clinical observations of a sample population to set a cutoff score. Then, the parental CFSS‐DS was used as a screening tool to survey the dental anxiety levels of 5‐ to 8‐year‐old children at kindergartens and elementary schools in Kaohsiung City, Taiwan. Participants were selected by stratified random sampling. The stratification was done by geographic district, age group, and sex. A total of 3,597 valid questionnaires were collected.

Results: The Chinese version of the CFSS‐DS had an optimal cutoff score of 38/39 (sensitivity was 0.857, specificity was 0.882) with an area under the ROC curve of 0.912. The estimated prevalence of dental anxiety among 5‐ to 8‐year‐old children in Kaohsiung City was 20.6 percent. The dental anxiety score was found to decrease as age increased; primary school boys had significantly lower scores.

Conclusions: The prevalence of dental anxiety was found to be high for 5‐ to 8‐year‐old Taiwanese children. The study’s findings point to the urgent need for preventive health education and intervention programs in Taiwan to promote children’s oral health and reduce dental anxiety.
Oral Health in Veterans Affairs Patients Diagnosed with Serious Mental Illness
Authors: Kilbourne Amy M. , Horvitz‐Lennon Marcela , Post Edward P. , McCarthy John F. , Cruz Mario , Welsh Deborah , Blow Frederic C.
Published: March 2007

Objectives: We evaluated patient and medication treatment factors associated with self‐reported oral health status in patients diagnosed with serious mental illness (SMI) in a large, national sample of patients in the Veterans Affairs (VA) health system.

Methods: 4,769 patients (mean age = 55, 7.8 percent women) were included from the VA’s 1999 National Psychosis Registry (NPR) for whom the oral health information gathered by the VA’s Large Health Survey of Veterans was available. Current (1999) psychotropic medication data were ascertained from the NPR. Multivariable logistic regression analyses were used to determine the patient factors (e.g., sociodemographic, enabling, and treatment factors) associated with poor or fair overall dental health, and with having tooth or mouth problems that made it difficult to eat.

Results: While 61.0 percent of persons with SMI self‐reported fair to poor dental health, 34.1 percent reported that oral health problems made it difficult for them to eat. Patients who were not employed, experiencing financial strain, who smoked, who were prescribed tricyclic antidepressants, or prescribed selective serotonin reuptake inhibitors were more likely to report poor or fair dental health. These variables were also associated with having tooth or mouth problems.

Conclusions: Suboptimal oral health was self‐reported with substantial pre‐valence among patients with SMI, a problematic finding given its consequences for general health, social functioning, and quality of life. Greater efforts are needed to improve oral health outcomes among patients with SMI by facilitating access to dental care and addressing mutable factors such as smoking and medication side effects.
Periodontal Health Status in a Cohort of Young US Navy Personnel
Authors: Diefenderfer Kim E. , Ahlf Renee L. , Simecek John W. , Levine Michael E.
Published: March 2007

Objectives: Neither the prevalence of periodontal disease nor long‐term trends in periodontal health among US military personnel has been well studied. The authors analyzed dental records to assess the prevalence and severity of periodontal disease, characterize changes in periodontal health, and determine the associations of age, race, gender, and tobacco use with periodontal status among US Navy personnel.

Methods: Dental records from 1,107 personnel who entered military service in 1997 were gathered from eight US Navy dental treatment facilities. Demographic information, tobacco use status, and periodontal health status, as reflected by the Periodontal Screening and Recording (PSR) information recorded at each required dental examination during the 4‐year observational period (1997 to 2001), were collected. To improve sensitivity in measuring the extent of periodontal disease, the standard five‐point PSR scale was reexpressed as a “PSR grade.”

Results: Over 98 percent of Navy recruits exhibited some level of periodontal disease at initial examination. Most (76 percent) exhibited gingivitis of varying severity. Over a mean observational period of 3.4 years, 91 percent of subjects received at least one oral prophylaxis, and over 60 percent received two to four prophylaxes. Subjects with severe periodontal conditions received as many as 22 appointments for prophylaxis or periodontal therapy. From initial to final examination, periodontal status improved for 29.2 percent of subjects, deteriorated for 31.3 percent, and remained unchanged for 39.5 percent. Subjects presenting initially with healthy periodontia, or gingivitis without evidence of periodontitis, tended to deteriorate or remain unchanged, while those exhibiting periodontitis tended to improve with periodontal therapy. Race (non‐White) and greater age at entry were significantly associated with increased risk for poorer periodontal health at both initial and final examination.

Conclusions: Although a needs‐based dental care model appears effective in managing periodontal disease among those receiving active therapy, patients who receive sporadic care may deteriorate over time. To maintain periodontal health in this population, appropriate preventive and periodontal therapies should be provided soon after entry and repeated at intervals specific to individual patient need.
Compliance with Fluoride Supplements Provided by a Dental Hygienist in Homes of Low‐Income Parents of Preschool Children in Quebec
Authors: Gagnon Fabien , Catellier Pierre , Arteau‐Gauthier Isabelle , Simard‐Tremblay Élisabeth , Lepage‐Saucier Marianne , Paradis‐Robert Nina , Michel Julie , Lavallière André
Published: March 2007

Objective: This study aimed to assess the compliance with fluoride supplements provided at home by a dental hygienist to mothers of at‐risk preschool children.

Methods: Participants were recruited during pregnancy of low‐income women. On the first visit, the mothers of 60 infants aged 6 to 9 months were handed free fluoride supplements. A questionnaire was administered at that time and after 6 and 12 months to assess compliance during the preceding week.

Results: At the beginning of the study, none of the mothers reported having given fluoride supplements, in comparison with 73 percent of mothers of 44 infants who received all three visits at the end of follow‐up; 48 percent reported fluoride supplement use on a daily basis.

Conclusions: Removal of financial and physical barriers and personal professional involvement are good strategies to achieve compliance with fluoride supplements. Further assessment regarding the possible application of this intervention to other professional or cultural contexts is warranted.
Study of Viscoplasticity Models for the Impact Behavior of High-Strength Steels
Authors: Peixinho N. , Pinho A.
Published: March 2007

This study reports on modeling the mechanical behavior of high-strength steels subjected to impact loading. The materials studied were steel grades of interest for crashworthiness applications: dual-phase and transformation induced plasticity (TRIP) steels. The challenges associated with the numerical simulation of impact events involving these materials include the modeling of extensive plastic deformation, particularly the change of material properties with strain rate. Tensile testing was performed at different strain rates on the materials studied. The test results were used to compare and validate constitutive equations that provide a mathematical description of strain-rate dependence of the material properties. The Cowper–Symonds equation and modified variants were examined. The crashworthiness performance of thin-walled sections made of dual-phase and TRIP steels was also investigated. Axial crushing tests were performed at different speeds on top-hat and hexagonal tubes. The experimental results were compared with numerical simulations obtained using an explicit finite element program (LS-DYNA) and the original and modified Cowper–Symonds equations.
Computational Modeling and Analysis of Multiple Steady States in Vapor Compression Systems
Authors: Mehta Prashant G. , Eisenhower Bryan A.
Published: March 2007

In this paper, we present a well-posed two-point boundary value problem framework for computing, via continuation, the steady states of interconnected vapor compression systems. We illustrate the ease and utility of our approach by employing the path following software AUTO to compute steady solutions of an experimental air-to-water heat pump that uses CO2 as a refrigerant. We validate some of the computational solutions against the experimental data and carry out continuation and bifurcation analysis in external parameters of practical interest. The results of these computations show that multiple and qualitatively distinct distributed steady-state solutions can arise for the problem, and that our approach provides for a simpler alternative to the much harder problem of dynamic simulation.
Forced Nonlinear Oscillations of a Semi-Infinite Beam Resting on a Unilateral Elastic Soil: Analytical and Numerical Solutions
Authors: Lancioni Giovanni , Lenci Stefano
Published: March 2007

The dynamics of a semi-infinite Euler–Bernoulli beam on unilateral elastic springs is investigated. The mechanical model is governed by a moving-boundary hyperbolic problem, which cannot be solved in closed form. Therefore, we look for approximated solutions following two different approaches. From the one side, approximate analytical solutions are obtained by means of perturbation techniques. On the other side, numerical solutions are determined by a self-made finite element algorithm. The analytical and numerical solutions are compared with each other, and the effects of the problem nonlinearity on the beam motion are analyzed. In particular, the superharmonics oscillations and the resonances are investigated in depth.
A Direct Simulation Monte Carlo Approach for the Analysis of Granular Damping
Authors: Fang X. , Tang J.
Published: March 2007

Granular damping, which possesses promising features for vibration suppression in harsh environments such as in turbo-machinery and spacecraft, has been studied using empirical analysis and more recently using the discrete element method (DEM). The mechanism of granular damping is nonlinear and, when numerical analyses are employed, usually a relatively long simulation time of structural vibration is needed to reflect the damping behavior. The present research explores the granular damping analysis by means of the direct simulation Monte Carlo (DSMC) approach. Unlike the DEM that tracks the motion of granules based upon the direct numerical integration of Newton’s equations, the DSMC is a statistical method derived from the Boltzmann equation to describe the velocity evolution of the granular system. Since the exact time and locations of contacts among granules are not calculated in the DSMC, a significant reduction in computational time/cost can be achieved. While the DSMC has been exercised in a variety of gas/granular systems, its implementation to granular damping analysis poses unique challenges. In this research, we develop a new method that enables the coupled analysis of the stochastic granular motion and the structural vibration. The complicated energy transfer and dissipation due to the collisions between the granules and the host structure and among the granules is directly analyzed, which is essential to damping evaluation. Also, the effects of granular packing ratio and the excluded volume of granules, which may not be considered in the conventional DSMC approach, are explicitly incorporated in the analysis. A series of numerical studies are performed to highlight the accuracy and efficiency of the new approach.
Superharmonic Resonance of Order 2 for an Impacting Hertzian Contact Oscillator: Theory and Experiments
Authors: Perret-Liaudet Joël , Rigaud Emmanuel
Published: March 2007

The purpose of this paper is to investigate experimental responses of a preloaded vibroimpact Hertzian contact to an order 2 superharmonic excitation. A test rig is used, corresponding to a double sphere–plane contact preloaded by the weight of a moving body. Typical response curves are obtained under the superharmonic excitation. The Hertzian nonlinearity constitutes the precursor of vibroimpacts established over a wide frequency range. This behavior can be related to the existence of a transcritical bifurcation. In conjuction with the experiments, numerical results lead to the same conclusion. In particular, the threshold level of the excitation necessary to induce vibroimpact is confirmed.
Making a fluid rotate: Circular flow of a weakly conducting fluid induced by a Lorentz body force
Authors: Digilov Rafael M.
Published: March 2007

We describe the magnetohydrodynamic (MHD) flow of a viscous, electrically conducting, and incompressible fluid driven by the Lorentz body force inside the annulus between two stationary coaxial cylindrical electrodes under imposed electric and magnetic fields. The azimuthal velocity profile is found for axisymmetrical, fully developed laminar and steady flow at arbitrary annulus curvature and different values of the Hartmann number Ha. It is shown that for Ha⩽1, the MHD annular flow behaves as a conventional hydrodynamic fluid driven by an azimuthal Lorentz body force.
Resource Letter PSEn-1: Physics and society: Energy
Authors: Hobson Art
Published: March 2007

This Resource Letter provides a guide to the physics-related literature about energy-and-society. Journal articles, books, and websites are cited for the following topics: general references, textbooks, other pedagogical resources, population growth, fossil fuels, global warming, nuclear power, side effects of nuclear power, fusion power, renewable resources (including hydroelectric, biofuels, wind, photovoltaics, direct solar, geothermal, hydrogen, and energy storage), energy efficiency, and transportation efficiency.
Automating data acquisition for the Cavendish balance to improve the measurement of G
Authors: Fitch Noah , Bliven Wesley , Mitchell Tyler
Published: March 2007

The Leybold-Heraeus gravitational torsion balance is commonly used in undergraduate laboratories to measure the gravitational attraction between known masses to find the gravitational constant G. Because the difficult task of data acquisition reduces its usefulness, we have implemented a simple design that minimizes this task and achieves more accurate results. This design features a small car that tracks the oscillating laser with the use of a stepper motor and some simple control circuitry. Step counting yields the location of the reflected laser in time.
Nonlinear damping of the LC circuit using antiparallel diodes
Authors: Hellen Edward H. , Lanctot Matthew J.
Published: March 2007

We investigate a simple variation of the series RLC circuit in which antiparallel diodes replace the resistor. The result is a damped harmonic oscillator with a nonlinear damping term that is a maximum at zero current and decreases inversely with the current for currents far from zero. Unlike the standard RLC circuit, the behavior of this circuit is amplitude dependent. The transient response makes a transition from underdamped to overdamped behavior, and the resonance response of the steady-state driven oscillator becomes sharper as the source amplitude increases. A set of nonlinear differential equations is derived for the circuit and integrated numerically for comparison with measurements. The equipment is inexpensive and common to upper level physics labs.
Comparative Activities of Daptomycin, Linezolid, and Tigecycline against Catheter-Related Methicillin-Resistant
Staphylococcus
Bacteremic Isolates Embedded in Biofilm
Authors: Raad Issam , Hanna Hend , Jiang Ying , Dvorak Tanya , Reitzel Ruth , Chaiban Gassan , Sherertz Robert , Hachem Ray
Published: March 2007

In the setting of catheter-related bloodstream infections, intraluminal antibiotic lock therapy could be useful for the salvage of vascular catheters. In this in vitro study, we investigated the efficacies of the newer antibiotics daptomycin, linezolid, and tigecycline, in comparison with those of vancomycin, minocycline, and rifampin, against methicillin-resistant
Staphylococcus aureus
(MRSA) embedded in biofilm. We also assessed the emergence of MRSA strains resistant to these antibiotics, alone or in combination with rifampin, after 4-hour daily use for catheter lock therapy. Minocycline, daptomycin, and tigecycline were more efficacious in inhibiting MRSA in biofilm than linezolid, vancomycin, and the negative control (
P
< 0.001) after the first day of exposure to these antibiotics, with minocycline being the most active, followed by daptomycin and then tigecycline, and with vancomycin and linezolid lacking activity, similar to the negative control. After 3 days of 4-hour daily exposures, daptomycin was the fastest in eradicating MRSA from biofilm, followed by minocycline and tigecycline, which were faster than linezolid, rifampin, and vancomycin (
P
< 0.001). When rifampin was used alone, it was the least effective in eradicating MRSA from biofilm after 5 days of 4-hour daily exposures, as it was associated with the emergence of rifampin-resistant MRSA. However, when rifampin was used in combination with other antibiotics, the combination was significantly effective in eliminating MRSA colonization in biofilm more rapidly than each of the antibiotics alone. In summary, daptomycin, minocycline, and tigecycline should be considered further for antibiotic lock therapy, and rifampin should be considered for enhanced antistaphylococcal activity but not as a single agent.
Single-Dose Oral Amoxicillin or Linezolid for Prophylaxis of Experimental Endocarditis Due to Vancomycin-Susceptible and Vancomycin-Resistant
Enterococcus faecalis
Authors: Moreillon Philippe , Wilson Walter R. , Leclercq Roland , Entenza José M.
Published: March 2007

Endocarditis prophylaxis following genitourinary or gastrointestinal procedures targets
Enterococcus faecalis
. Prophylaxis recommendations advocate oral amoxicillin (2 g in the United States and 3 g in the United Kingdom) in moderate-risk patients and intravenous amoxicillin (2 g) or vancomycin (1 g) plus gentamicin in high-risk patients. While ampicillin-resistant (or amoxicillin-resistant)
E. faecalis
is still rare, there is a concern that these regimens might fail against vancomycin-resistant and/or aminoglycoside-resistant isolates. The present study tested oral linezolid as an alternative. Rats with catheter-induced aortic vegetations were given prophylaxis simulating human pharmacokinetics of oral amoxicillin (2- to 3-g single dose), oral linezolid (600 mg, single or multiple oral doses every 12 h), or intravenous vancomycin (1-g single dose). Rats were then inoculated with the minimum inoculum infecting 90% of the animals (90% infective dose [ID
90
]) or with 10 times the ID
90
of the vancomycin-susceptible
E. faecalis
strain JH2-2 or the vancomycin-resistant (VanA phenotype)
E. faecalis
strain UCN41. Amoxicillin was also tested with two additional vancomycin-susceptible
E. faecalis
strains, 309 and 1209. Animals were sacrificed 3 days later. All the tested bacteria were susceptible to amoxicillin and gentamicin. Single-dose amoxicillin provided 100% protection against all four isolates at both the ID
90
and 10 times the ID
90
. In contrast, linezolid required up to four consecutive doses to provide full protection against the vancomycin-resistant isolate. Vancomycin protected only against the vancomycin-susceptible strain. The high efficacy of single-dose oral amoxicillin suggests that this regimen could be used for prophylaxis in both moderate-risk and high-risk patients without additional aminoglycosides. Linezolid appears to be less reliable, at least against the vancomycin-resistant strain.
Immunomodulatory Effects of Fosfomycin in Experimental Human Endotoxemia
Authors: Sauermann Robert , Marsik Claudia , Steiner Ilka , Seir Katja , Cvitko Tuende , Zeitlinger Markus , Wagner Oswald , Joukhadar Christian
Published: March 2007

To evaluate the effect of fosfomycin on proinflammatory cytokines, a bolus of 2 ng of bacterial lipopolysaccharide/kg of body weight was injected intravenously into healthy volunteers. After 2 h, subjects received 8 g of fosfomycin or placebo in a randomized crossover study design. The resulting concentrations of tumor necrosis factor alpha, interleukin-1β (IL-1β), and IL-6 expressed as protein and mRNA levels were almost identical with and without fosfomycin.
Preclinical Safety Assessments of UC781 Anti-Human Immunodeficiency Virus Topical Microbicide Formulations
Authors: Patton D. L. , Sweeney Y. T. Cosgrove , Balkus J. E. , Rohan L. C. , Moncla B. J. , Parniak M. A. , Hillier S. L.
Published: March 2007

The nonnucleoside reverse transcriptase inhibitor UC781 is under development as a potential microbicide to prevent sexual transmission of human immunodeficiency virus type 1 (HIV-1). Two gel formulations of UC781 (0.1% and 1.0%) were evaluated in a range of preclinical safety assessments, including systemic absorption analysis following topical application in the pig-tailed macaque models for vaginally and rectally applied topical microbicides. High-sensitivity high-performance liquid chromatography analysis of serum samples showed that no systemic absorption of UC781 was detected after repeated vaginal or rectal application of either product. However, high levels of UC781 were detectable in the cervicovaginal lavage samples up to 6 h after product exposure. Both formulations were safe to the vaginal microenvironment, even with repeated daily use, as evidenced by colposcopy, cytokine analysis, and lack of impact on vaginal microflora. By contrast, rectal application of the 1.0% UC781 formulation caused an increased expression of numerous cytokines not observed after rectal application of the 0.1% UC781 formulation. These results provide additional support for the continued development of UC781 formulations as anti-HIV microbicides.
Asiatic Acid and Corosolic Acid Enhance the Susceptibility of
Pseudomonas aeruginosa
Biofilms to Tobramycin
Authors: Garo Eliane , Eldridge Gary R. , Goering Matt G. , Pulcini Elinor DeLancey , Hamilton Martin A. , Costerton John W. , James Garth A.
Published: March 2007

Asiatic acid and corosolic acid are two natural products identified as biofilm inhibitors in a biofilm inhibition assay. We evaluated the activities of these two compounds on
Pseudomonas aeruginosa
biofilms grown in rotating disk reactors (RDRs) in combination with tobramycin and ciprofloxacin. To determine the ruggedness of our systems, the antibiotic susceptibilities of these biofilms were assessed with tobramycin and ciprofloxacin. The biofilm bacteria produced in the RDR were shown to display remarkable tolerance to 10 μg/ml of ciprofloxacin, thus mimicking the tolerance observed in recalcitrant bacterial infections. These studies further demonstrate that a nonmucoid strain of
P. aeruginosa
can form a biofilm that tolerates ciprofloxacin at clinically relevant concentrations. Neither asiatic acid nor corosolic acid reduced the viable cell density of
P. aeruginosa
biofilms. However, both compounds increased the susceptibility of biofilm bacteria to subsequent treatment with tobramycin, suggesting asiatic acid and corosolic acid to be compounds that potentiate the activity of antibiotics. A similar statistical interaction was observed between ciprofloxacin and subsequent treatment with tobramycin.
Comparison of the Phosphorylation of 4′-Ethynyl 2′,3′-Dihydro-3′-Deoxythymidine with That of Other Anti-Human Immunodeficiency Virus Thymidine Analogs
Authors: Hsu Chih-Hung , Hu Rong , Dutschman Ginger E. , Yang Guangwei , Krishnan Preethi , Tanaka Hiromichi , Baba Masanori , Cheng Yung-Chi
Published: March 2007

Thymidine analogs, including 3′-azido-3′-deoxythymidine (AZT) and 2′,3′-dideoxy-3′-deoxythymidine (D4T), are important antiretroviral agents. To exert antiretroviral activity, these analogs undergo a stepwise phosphorylation intracellularly to the active triphosphate metabolites. We previously reported that 4′-substituted D4T with an ethynyl group (i.e., 4′-ethynyl D4T) increased the anti-human immunodeficiency virus (HIV) activity and was active against multidrug-resistant HIV strains. 4′-Ethynyl D4T is a better substrate for phosphorylation by human thymidine kinase 1 than D4T is. In this report, we first studied the enzymes involved in the phosphorylation of 4′-ethynyl D4T from monophosphate to triphosphate metabolites. The 4′-ethynyl D4TMP is phosphorylated by recombinant human TMP kinase with aKmof 19 ± 4 μM and akcatof 0.007 ± 0.001 s−1; the relative efficiency is about 9 and 15% of those of D4TMP and AZTMP, respectively. Several enzymes from crude cellular extracts, including nucleoside diphosphate kinase, pyruvate kinase, creatine kinase, and 3-phosphoglycerate kinase, could phosphorylate 4′-ethynyl D4T-diphosphate. The relative phosphorylation efficiencies of 4′-ethynyl D4TDP were about 3 to 25% of those of D4TDP and were generally similar to those of AZTDP. In T-lymphoid cell lines, there was a preponderant accumulation of 4′-ethynyl D4TMP, suggesting that TMP kinase could be the rate-limiting enzyme in the metabolism of 4′-ethynyl D4T. Although the same enzymes are involved in the stepwise phosphorylation of thymidine analogs, their behaviors in phosphorylating metabolites of 4′-ethynyl D4T are different from those of D4T and AZT. Qualitatively, the metabolism of 4′-ethynyl D4T is more similar to that of AZT than to that of its progenitor, D4T.
SCO-1, a Novel Plasmid-Mediated Class A β-Lactamase with Carbenicillinase Characteristics from
Escherichia coli
Authors: Papagiannitsis C. C. , Loli A. , Tzouvelekis L. S. , Tzelepi E. , Arlet G. , Miriagou V.
Published: March 2007

A novel class A β-lactamase (SCO-1) encoded by an 80-kb self-transferable plasmid from
Escherichia coli
is described. The interaction of SCO-1 with β-lactams was similar to that of the CARB-type enzymes. Also, SCO-1 exhibited a 51% amino acid sequence identity with the RTG subgroup of chromosomal carbenicillinases (RTG-1, CARB-5, and CARB-8).
Covalent Dimer Species of β-Defensin Defr1 Display Potent Antimicrobial Activity against Multidrug-Resistant Bacterial Pathogens
Authors: Taylor Karen , McCullough Bryan , Clarke David J. , Langley Ross J. , Pechenick Tali , Hill Adrian , Campopiano Dominic J. , Barran Perdita E. , Dorin Julia R. , Govan John R. W.
Published: March 2007

Beta defensins comprise a family of cationic, cysteine-rich antimicrobial peptides, predominantly expressed at epithelial surfaces. Previously we identified a unique five-cysteine defensin-related peptide (Defr1) that, when synthesized, is a mixture of dimeric isoforms and exhibits potent antimicrobial activity against
Escherichia coli
and
Pseudomonas aeruginosa
. Here we report that Defr1 displays antimicrobial activity against an extended panel of multidrug-resistant nosocomial pathogens for which antimicrobial treatment is limited or nonexistent. Defr1 fractions were collected by high-pressure liquid chromatography and analyzed by gel electrophoresis and mass spectrometry. Antimicrobial activity was initially investigated with the type strain
Pseudomonas aeruginosa
PAO1. All fractions tested displayed equivalent, potent antimicrobial activity levels comparable with that of the unfractionated Defr1. However, use of an oxidized, monomeric six-cysteine analogue (Defr1 Y5C), or of reduced Defr1, gave diminished antimicrobial activity. These results suggest that the covalent dimer structure of Defr1 is crucial to antimicrobial activity; this hypothesis was confirmed by investigation of a synthetic one-cysteine variant (Defr1-1cys). This gave an activity profile similar to that of synthetic Defr1 but only in an oxidized, dimeric form. Thus, we have shown that covalent, dimeric molecules based on the Defr1 β-defensin sequence demonstrate antimicrobial activity even in the absence of the canonical cysteine motif.
Induction of Cell Signaling Events by the Cholera Toxin B Subunit in Antigen-Presenting Cells
Authors: Schnitzler Aletta C. , Burke Jennifer M. , Wetzler Lee M.
Published: March 2007

Cholera toxin (CT) is one of the most effective and widely studied mucosal adjuvants. Although the ADP-ribosylating A subunit has been implicated in augmenting immune responses, the receptor-binding B subunit (CT-B) has greater immunogenicity and may be a repository of adjuvant activity without potential toxicity. In order to elucidate mechanisms of immune modulation by CT-B alone, primary B cells and macrophages were assessed for responses to CT-B in vitro, as measured by the expression of cell surface markers, cellular signaling events, and cytokine secretion. Increased phosphorylation of multiple signaling molecules, including Erk1/2 and p38, was detected. CT-B also induced transactivation of the transcription elements cyclic AMP-responsive element and NF-κB, the latter of which was inhibited by phosphotyrosine inhibition. While specific inhibition of MEK1/2 did not reduce CT-B induction of cell surface marker expression, it did attenuate CT-B-mediated interleukin-6 secretion. These data show that CT-B induces a set of signaling events related to cellular activation, surface molecule expression, and cytokine production that has potential implications for elucidating CT-B adjuvant activity in the absence of enzymatically active holotoxin.
EMBEDDING ERGODIC ACTIONS OF COMPACT QUANTUM GROUPS ON C*-ALGEBRAS INTO QUOTIENT SPACES
Authors: PINZARI CLAUDIA
Published: March 2007

The notion of compact quantum subgroup is revisited and an alternative definition is given. Induced representations are considered and a Frobenius reciprocity theorem is obtained. A relationship between ergodic actions of compact quantum groups on C*-algebras and topological transitivity is investigated. A sufficient condition for embedding such actions in quantum quotient spaces is obtained.
GALOIS GROUPS AND AN OBSTRUCTION TO PRINCIPAL GRAPHS OF SUBFACTORS
Authors: ASAEDA MARTA
Published: March 2007

The Galois group of the minimal polymonal of a Jones index value gives a new type of obstruction to a principal graph, thanks to a recent result of Etingof, Nikshych, and Ostrik. We show that the sequence of the graphs given by Haagerup as candidates of principal graphs of subfactors, are not realized as principal graphs for 7 < n ≤ 27 using GAP program. We further utilize Mathematica to extend the statement to 27 < n ≤ 55. We conjecture that none of the graphs are principal graphs for all n > 7, and give an evidence using Mathematica for smaller graphs among them for n > 55. The problem for the case n = 7 remains open, however, it is highly likely that it would be realized as a principal graph, thanks to numerical computation by Ikeda.
NON-COMPACT BOUNDARIES OF COMPLEX ANALYTIC VARIETIES
Authors: DELLA SALA GIUSEPPE , SARACCO ALBERTO
Published: March 2007

We treat the boundary problem for complex varieties with isolated singularities, of dimension greater than one, which are contained in a certain class of strongly pseudoconvex, not necessarily bounded open subsets of ℂn. We deal with the problem by cutting with a family of complex hyperplanes and applying the classical Harvey–Lawson's theorem for the bounded case [6].
Changes in Osmolality Sensitize the Response to Capsaicin in Trigeminal Sensory Neurons
Authors: Liu Lieju , Chen Lei , Liedtke Wolfgang , Simon S. A.
Published: March 2007

Changes in tonicity in the peripheral nervous system can activate nociceptors and produce pain. Under local inflammatory conditions the peripheral terminals of nociceptors are subject to deviations from isotonicity. Previously it was shown that several members of the TRP(V) family of ion channels are responsive to changes in tonicity. Here we explore how changes in tonicity affect TRPV1 receptor-mediated responses to capsaicin in dissociated rat trigeminal ganglion (TG) neurons. Using whole cell patch-clamp and calcium imaging, we found that mild anisotonicity (260 and 348 mOsm/kg for hypotonicity and hypertonicity, respectively) strikingly sensitized the capsaicin-evoked current, Icaps. Confocal immunolocalization studies also revealed a modest anisotonicity-mediated redistribution of TRPV1 toward the plasma membrane of TG neurons. With respect to downstream signaling pathways, tonicity-induced sensitization of Icaps was dependent on whether hypo- or hypertonic stimuli were applied. Specifically, antagonism of PKA- and PI3K-activated pathways appreciably reduced the hypertonicity-induced sensitization of Icaps, whereas inhibition of PKC-mediated pathways selectively reduced the sensitization produced by hypotonic solutions. In summary, whereas the overall effects of hypo- and hypertonicity resulted in a similar pattern of potentiation of Icaps, intracellular signaling pathways were selective for hypo- versus hypertonicity-induced tuning of capsaicin-activated currents.
Positive Pretransplantation Cytomegalovirus Serology Is a Risk Factor for Cardiac Allograft Vasculopathy in Children
Authors: Hussain Tarique , Burch Michael , Fenton Matthew J. , Whitmore Pauline M. , Rees Philip , Elliott Martin , Aurora Paul
Published: March 2007

Background—

Cytomegalovirus (CMV) infection has been implicated as a cause of posttransplantation coronary artery disease in adults. The purpose of this retrospective observational study was to evaluate the effect of CMV on outcome after heart transplantation in children.

Methods and Results—

Risk factors tested were recipient age, sex, and pretransplantation CMV serology; use of anti-CMV prophylaxis; posttransplantation evidence of CMV infection; and donor CMV serology. Transplantations were stratified traditionally according to CMV risk as low risk (recipient negative/donor negative), intermediate risk (recipient positive), and high risk (recipient negative/donor positive). Primary outcome measures were (1) development of coronary artery vasculopathy, (2) mortality (or graft loss) that occurred outside the early postoperative period, and (3) death (or graft loss) due to vasculopathy. Analysis was by proportional hazards modeling. A total of 165 children underwent heart transplantation, with a mean age at transplantation of 7.8 (SD 5.6) years. Thirty-two children had laboratory evidence of CMV infection after transplantation, but only 6 developed CMV disease or syndrome. Traditional CMV risk stratification correlated well with CMV infection but did not predict mortality, coronary artery disease, or coronary death. In contrast, positive recipient CMV was the only independent predictor of all 3 outcome measures: coronary artery disease (hazard ratio=3.6), all-cause mortality (partial hazard ratio=4.1), and coronary death (hazard ratio=4.6).

Conclusions—

In children, pretransplantation recipient CMV status is a more powerful predictor for the development of clinically significant vasculopathy and subsequent death than traditional risk stratification. This phenomenon warrants further investigation.
Prevalence and Prognostic Significance of Heart Failure Stages
Authors: Ammar Khawaja Afzal , Jacobsen Steven J. , Mahoney Douglas W. , Kors Jan A. , Redfield Margaret M. , Burnett John C. , Rodeheffer Richard J.
Published: March 2007

Background—

Heart failure (HF) is a progressive disorder associated with frequent morbidity and mortality. An American Heart Association/American College of Cardiology staging classification of HF has been developed to emphasize early detection and prevention. The prevalence of HF stages and their association with mortality are unknown. We sought to estimate HF stage prevalence in the community and to measure the association of HF stages with mortality.

Methods and Results—

A population-based, cross-sectional, random sample of 2029 Olmsted County, Minnesota, residents aged ≥45 years was identified. Participants were classified by medical record review, symptom questionnaire, physical examination, and echocardiogram as follows: stage 0, healthy; stage A, HF risk factors; stage B, asymptomatic cardiac structural or functional abnormalities; stage C, HF symptoms; and stage D, severe HF. In the cohort, 32% were stage 0, 22% stage A, 34% stage B, 12% stage C, and 0.2% stage D. Mean B-type natriuretic peptide concentrations (in pg/mL) increased by stages: stage 0=26, stage A=32, stage B=53, stage C=137, and stage D=353. Survival at 5 years was 99% in stage 0, 97% in stage A, 96% in stage B, 75% in stage C, and 20% in stage D.

Conclusions—

The present study provides prevalence estimates and prognostic validation for HF staging in a community cohort. Of note, 56% of adults ≥45 years of age were classified as being in stage A (risk factors) or B (asymptomatic ventricular dysfunction). HF staging underscores the magnitude of the population at risk for progression to overt HF.
Cardioprotection by Ecto-5′-Nucleotidase (CD73) and A
2B
Adenosine Receptors
Authors: Eckle Tobias , Krahn Thomas , Grenz Almut , Köhler David , Mittelbronn Michel , Ledent Catherine , Jacobson Marlene A. , Osswald Hartmut , Thompson Linda F. , Unertl Klaus , Eltzschig Holger K.
Published: March 2007

Background—

Ecto-5′-nucleotidase (CD73)–dependent adenosine generation has been implicated in tissue protection during acute injury. Once generated, adenosine can activate cell-surface adenosine receptors (A
1
AR, A
2A
AR, A
2B
AR, A
3
AR). In the present study, we define the contribution of adenosine to cardioprotection by ischemic preconditioning.

Methods and Results—

On the basis of observations of CD73 induction by ischemic preconditioning, we found that inhibition or targeted gene deletion of
cd73
abolished infarct size-limiting effects. Moreover, 5′-nucleotidase treatment reconstituted

cd73
−/−

mice and attenuated infarct sizes in wild-type mice. Transcriptional profiling of adenosine receptors suggested a contribution of A
2B
AR because it was selectively induced by ischemic preconditioning. Specifically, in situ ischemic preconditioning conferred cardioprotection in

A
1
AR
−/−

,

A
2A
AR
−/−

, or

A
3
AR
−/−

mice but not in

A
2B
AR
−/−

mice or in wild-type mice after inhibition of the A
2B
AR. Moreover, A
2B
AR agonist treatment significantly reduced infarct sizes after ischemia.

Conclusions—

Taken together, pharmacological and genetic evidence demonstrate the importance of CD73-dependent adenosine generation and signaling through A
2B
AR for cardioprotection by ischemic preconditioning and suggests 5′-nucleotidase or A
2B
AR agonists as therapy for myocardial ischemia.