bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of School Socioeconomic Status on Student Lunch Consumption after Implementation of the Texas Public School Nutrition Policy*
Authors: Cullen Karen Weber , Watson Kathleen B. , Fithian Ashley R.
Published: October 2009

BACKGROUND: This study compares the impact of the Texas Public School Nutrition Policy on lunch consumption of low‐ and middle‐income students in sixth through eighth grades.

METHODS: Students in 1 middle socioeconomic status (SES) and 1 low SES school completed lunch food records before (2001/2002) and after (2005/2006) implementation of the Texas policy. Students recorded amount and source of foods/beverages consumed. Two‐way analyses of variance with year and school SES as factors were performed to compare consumption by school SES before and after implementation of the Texas policy.

RESULTS: Regardless of year, the low SES group consumed less fat, sweetened beverages, and candy and more vitamin C and calcium than the middle SES group. There were more significant improvements in dietary patterns for the middle SES school students post‐policy, particularly from the National School Lunch Program (NSLP) meal. The middle SES school students reported significantly higher percentages of less healthy items from home post‐policy.

CONCLUSIONS: Overall, low SES school students consumed more healthy lunches at school compared with middle SES school students, and the Texas policy improved middle SES school student dietary intakes. Whether the dietary behaviors in school influence dietary intake for the entire day is unknown.
The Impact of Nutrition Standards on Competitive Food Offerings and Purchasing Behaviors of High School Students
Authors: Snelling Anastasia M. , Kennard Teha
Published: October 2009

BACKGROUND: With adolescent obesity rates on the rise, the school food environment is receiving closer scrutiny. This study looks at the effects of nutrient standards as part of a wellness policy that was implemented in 3 public high schools in 1 county, by analyzing the nutritional value of competitive food offerings and purchases before and after the development of the standards.

METHODS: All food offerings and purchases were labeled based on their nutritional density using a stoplight approach of green, yellow, and red colors for the pre‐ and post‐ period. The stoplight approach to ranking foods is on a continuum of nutrient density, with green foods being the healthiest choices and red foods offering minimal nutrient density.

RESULTS: Results showed that after the implementation of the standards, red foods made up 30% of offerings, down from 48% of offerings prior to the existence of the guidelines. The proportion of red food purchases also decreased, from 83% to 47%. Additionally, yellow food offerings increased from 18% to 48% and purchases increased from 6% to 34%.

CONCLUSION: Results indicate that the nutrient standards as part of the wellness policy contributed to a positive shift in the nutritional value of competitive food purchases and offerings.
Clustering of Internet Risk Behaviors in a Middle School Student Population
Authors: Dowell Elizabeth B. , Burgess Ann W. , Cavanaugh Deborah J.
Published: October 2009

BACKGROUND: Internet safety is a growing public concern especially among adults and youth who live in an “instant messaging” world of technological communication. To better understand how early adolescents are using the Internet, a study was undertaken to more clearly identify the online general use, safety knowledge, and risk behaviors of middle school students.

METHODS: This exploratory study adapted from Finkelhor et al's (2000) Youth Internet Safety Survey to identify the usage and characteristics of online youth, solicitation of youth, and searching for pornography or delinquent behaviors. The 404 students who were recruited from public and parochial schools consisted of both boys and girls with a mean age 12 years.

RESULTS: These students reported the beginnings of high‐risk Internet behavior, specifically, giving out personal information, using the Internet to harass or embarrass another person, and for a small number of students, chatting with strangers and starting relationships. The students who posted their picture online were more likely to have sent their picture to someone, made rude comments to others, played online jokes, harassed or embarrassed someone, and sought out pornographic sites.

CONCLUSIONS: Findings suggest that middle school students who are early adolescents are beginning risky behaviors on the Internet. Risk‐taking behavior is not unique to adolescents, but the consequences can be detrimental to their development. Educators, clinicians, health care providers, and other professionals need to be informed of Internet behaviors in order to assess for children at risk, to make referrals, intervene, and to educate parents.
Development and Reliability of Items Measuring the Nonmedical Use of Prescription Drugs for the Youth Risk Behavior Survey: Results From an Initial Pilot Test
Authors: Howard Melissa M. , Weiler Robert M. , Haddox J. David
Published: October 2009

BACKGROUND: The purpose of this study was to develop and test the reliability of self‐report survey items designed to monitor the nonmedical use of prescription drugs among adolescents.

METHODS: Eighteen nonmedical prescription drug items designed to be congruent with the substance abuse items in the US Centers for Disease Control and Prevention's (CDC's) Youth Risk Behavior Survey were constructed, reviewed by a panel of experts, and then examined to assess reliability using a test‐retest survey design.

RESULTS: Simple kappa (κ) coefficients for 14 of the 18 items demonstrated “substantial” or “almost perfect” reliability. Three items had coefficients within the “fair” or “moderate” ranges and 1 item fell within in the “poor” range. Of the 10 items for which weighted κ coefficients were calculated, 6 items fell within the “almost perfect” or “substantial” ranges. Three fell within the “moderate” range and 1 fell within the “poor” range.

CONCLUSIONS: Based on the expert panel review and the findings from our study, most of the 18 items developed to measure nonmedical use of prescription drugs among adolescents appear valid and reliable. The nonmedical use of prescription drugs ranks fourth among the most abused class of drugs by adolescents after alcohol, tobacco, and marijuana, respectively. The CDC should consider expanding the surveillance of these specific health‐risk behaviors that are assuming new importance by including the items described in this article in future national surveys.
Penalized Regression with Ordinal Predictors
Authors: Gertheiss Jan , Tutz Gerhard
Published: October 2009

Ordered categorial predictors are a common case in regression modelling. In contrast to the case of ordinal response variables, ordinal predictors have been largely neglected in the literature. In this paper, existing methods are reviewed and the use of penalized regression techniques is proposed. Based on dummy coding two types of penalization are explicitly developed; the first imposes a difference penalty, the second is a ridge type refitting procedure. Also a Bayesian motivation is provided. The concept is generalized to the case of non‐normal outcomes within the framework of generalized linear models by applying penalized likelihood estimation. Simulation studies and real world data serve for illustration and to compare the approaches to methods often seen in practice, namely simple linear regression on the group labels and pure dummy coding. Especially the proposed difference penalty turns out to be highly competitive.
Analysis of Covariance with Non‐normal Errors
Authors: Şenoğlu Birdal , Avcıoğlu Mubeccel Didem
Published: October 2009

Analysis of covariance techniques have been developed primarily for normally distributed errors. We give solutions when the errors have non‐normal distributions. We show that our solutions are efficient and robust. We provide a real‐life example.
Mitochondrial DNA barcoding detects some species that are real, and some that are not
Authors: DASMAHAPATRA KANCHON K. , ELIAS MARIANNE , HILL RYAN I. , HOFFMAN JOSEPH I. , MALLET JAMES
Published: October 2009

Mimicry and extensive geographical subspecies polymorphism combine to make species in the ithomiine butterfly genus Mechanitis (Lepidoptera; Nymphalidae) difficult to determine. We use mitochondrial DNA (mtDNA) barcoding, nuclear sequences and amplified fragment length polymorphism (AFLP) genotyping to investigate species limits in this genus. Although earlier biosystematic studies based on morphology described only four species, mtDNA barcoding revealed eight well‐differentiated haplogroups, suggesting the presence of four new putative ‘cryptic species’. However, AFLP markers supported only one of these four new ‘cryptic species’ as biologically meaningful. We demonstrate that in this genus, deep genetic divisions expected on the basis of mtDNA barcoding are not always reflected in the nuclear genome, and advocate the use of AFLP markers as a check when mtDNA barcoding gives unexpected results.
Lattice corneal dystrophy, gelsolin type (Meretoja’s syndrome)
Authors: Carrwik Christian , Stenevi Ulf
Published: October 2009

Purpose:  This paper reviews current knowledge about the pathogenesis, clinical manifestations and treatment of lattice corneal dystrophy, gelsolin type (LCD2, Meretoja’s syndrome).

Methods:  Material is derived from literature searches, a case study of a Finnish patient living in Sweden, and interviews in Helsinki with Professor Ahti Tarkkanen and Dr Sari Kiuru‐Enari, both of whom have extensive first‐hand experience in treating patients with the disease.

Results:  The disease is now reported from several countries in Europe, as well as Japan, the USA and Iran. Treatment is symptomatic and is based on eye lubrication combined with rigorous monitoring of intraocular pressure to reduce corneal haze and postpone the need for keratoplasty. When systemic symptoms occur, the ophthalmologist should consult other specialists.

Conclusions:  The disease is probably under‐reported and is almost certainly to be found in more countries, including Sweden. Every ophthalmologist should be vigilant and consider this diagnosis when discovering a corneal lattice dystrophy, especially because the disease is an inherited, lifelong chronic condition with systemic symptoms.
Zofenopril Plus Hydrochlorothiazide Fixed Combination in the Treatment of Hypertension and Associated Clinical Conditions
Authors: Omboni Stefano , Malacco Ettore , Parati Gianfranco
Published: October 2009

Zofenopril, is a highly lipophilic ACE inhibitor, characterized by long‐lasting tissue penetration and sustained cardiac ACE inhibition, indicated for the treatment of hypertension and myocardial infarction. Comparative studies with different antihypertensive drug classes have demonstrated the good efficacy and tolerability of this compound in the management of the patient with mild–moderate hypertension. Zofenopril may also be combined with hydrochlorothiazide, a combination which has proved to be effective and safe as compared with monotherapy with either agent in three studies, including more than 600 patients. In addition, recent post hoc analyses in high‐risk patients, such as those with the metabolic syndrome, impaired fasting glucose or diabetes, atherogenic dyslipidemia, and impaired renal function, have confirmed the superiority of zofenopril 30 mg plus hydrochlorothiazide 12.5 mg once‐daily combination as compared with zofenopril monotherapy also in these high‐risk populations of patients with hypertension. These data suggest the usefulness of this fixed combination in the treatment of patients with hypertension requiring more prompt, intensive, and sustained blood pressure reduction, according to guidelines recommendation.
Photostimulation of channelrhodopsin‐2 expressing ventrolateral medullary neurons increases sympathetic nerve activity and blood pressure in rats
Authors: Abbott Stephen B. G. , Stornetta Ruth L. , Socolovsky Carmela S. , West Gavin H. , Guyenet Patrice G.
Published: October 2009

To explore the specific contribution of the C1 neurons to blood pressure (BP) control, we used an optogenetic approach to activate these cells in vivo. A lentivirus that expresses channelrhodopsin‐2 (ChR2) under the control of the catecholaminergic neuron‐preferring promoter PRSx8 was introduced into the rostral ventrolateral medulla (RVLM). After 2–3 weeks, ChR2 was largely confined to Phox2b‐expressing neurons (89%). The ChR2‐expressing neurons were non‐GABAergic, non‐glycinergic and predominantly catecholaminergic (∼54%). Photostimulation of ChR2‐transfected RVLM neurons (473 nm, 20 Hz, 10 ms, ∼9 mW) increased BP (15 mmHg) and sympathetic nerve discharge (SND; 64%). Light pulses at 0.2–0.5 Hz evoked a large sympathetic nerve response (16 × baseline) followed by a silent period (1–2 s) during which another stimulus evoked a reduced response. Photostimulation activated most (75%) RVLM baroinhibited neurons sampled with 1/1 action potential entrainment to the light pulses and without accommodation during 20 Hz trains. RVLM neurons unaffected by either CO2 or BP were light‐insensitive. Bötzinger respiratory neurons were activated but their action potentials were not synchronized to the light pulses. Juxtacellular labelling of recorded neurons revealed that, of these three cell types, only the cardiovascular neurons expressed the transgene. In conclusion, ChR2 expression had no discernable effect on the putative vasomotor neurons at rest and was high enough to allow precise temporal control of their action potentials with light pulses. Photostimulation of RVLM neurons caused a sizable sympathoactivation and rise in blood pressure. These results provide the most direct evidence yet that the C1 neurons have a sympathoexcitatory function.
Safety and Pharmacokinetics of Urtoxazumab, a Humanized Monoclonal Antibody, against Shiga-Like Toxin 2 in Healthy Adults and in Pediatric Patients Infected with Shiga-Like Toxin-Producing
Escherichia coli
Authors: López Eduardo L. , Contrini Maria M. , Glatstein Eduardo , González Ayala Silvia , Santoro Roberto , Allende Daniel , Ezcurra Gustavo , Teplitz Eduardo , Koyama Tamotsu , Matsumoto Yoichi , Sato Hiroaki , Sakai Kazuaki , Hoshide Satoru , Komoriya Keiji , Morita Takuya , Harning Ronald , Brookman Sheldon
Published: October 2009

Shiga-like toxin-producing
Escherichia coli
(STEC) infection causes diarrhea, which is often bloody and which can result in potentially life-threatening hemolytic-uremic syndrome (HUS). Urtoxazumab, a humanized monoclonal antibody directed against the Shiga-like toxin 2 (Stx2) produced by STEC, has been developed as a promising agent for the prevention of HUS. Single randomized, intravenous, double-blind, placebo-controlled doses of urtoxazumab were administered to assess its safety and pharmacokinetics in healthy adults (0.1 to 3.0 mg/kg of body weight) and STEC-infected pediatric patients (1.0 and 3.0 mg/kg). No dose-related safety trends were noted, nor were antiurtoxazumab antibodies detected. The disposition of urtoxazumab showed a biexponential decline, regardless of the dose. In healthy adults, the mean terminal elimination half-life was consistent across the dose groups and ranged from 24.6 days (3.0-mg/kg dose group) to 28.9 days (0.3-mg/kg dose group). The mean maximum serum drug concentration (
C
max
) ranged from 2.6 μg/ml at 0.1 mg/kg to 71.7 μg/ml at 3.0 mg/kg. The disposition of urtoxazumab following the administration of doses of 1.0 and 3.0 mg/kg in pediatric patients showed mean
C
max
s of 19.6 and 56.1 μg/ml, respectively. Urtoxazumab was well tolerated, appears to be safe at doses of up to 3.0 mg/kg, and is a potential candidate for the prevention of HUS in pediatric patients.
Structure of the Heme Biosynthetic
Pseudomonas aeruginosa
Porphobilinogen Synthase in Complex with the Antibiotic Alaremycin
Authors: Heinemann Ilka U. , Schulz Claudia , Schubert Wolf-Dieter , Heinz Dirk W. , Wang Yang-G. , Kobayashi Yuichi , Awa Yuuki , Wachi Masaaki , Jahn Dieter , Jahn Martina
Published: October 2009

The recently discovered antibacterial compound alaremycin, produced by
Streptomyces
sp. A012304, structurally closely resembles 5-aminolevulinic acid, the substrate of porphobilinogen synthase. During the initial steps of heme biosynthesis, two molecules of 5-aminolevulinic acid are asymmetrically condensed to porphobilinogen. Alaremycin was found to efficiently inhibit the growth of both Gram-negative and Gram-positive bacteria. Using the newly created heme-permeable strain
Escherichia coli
CSA1, we are able to uncouple heme biosynthesis from bacterial growth and demonstrate that alaremycin targets the heme biosynthetic pathway. Further studies focused on the activity of alaremycin against the opportunistic pathogenic bacterium
Pseudomonas aeruginosa
. The MIC of alaremycin was determined to be 12 mM. Alaremycin was identified as a direct inhibitor of recombinant purified
P. aeruginosa
porphobilinogen synthase and had a

K
i

of 1.33 mM. To understand the molecular basis of alaremycin's antibiotic activity at the atomic level, the
P. aeruginosa
porphobilinogen synthase was cocrystallized with the alaremycin. At 1.75-Å resolution, the crystal structure reveals that the antibiotic efficiently blocks the active site of porphobilinogen synthase. The antibiotic binds as a reduced derivative of 5-acetamido-4-oxo-5-hexenoic acid. The corresponding methyl group is, however, not coordinated by any amino acid residues of the active site, excluding its functional relevance for alaremycin inhibition. Alaremycin is covalently bound by the catalytically important active-site lysine residue 260 and is tightly coordinated by several active-site amino acids. Our data provide a solid structural basis to further improve the activity of alaremycin for rational drug design. Potential approaches are discussed.
Relative Contributions of Active Mediated Transport and Passive Diffusion of Fluoroquinolones with Various Lipophilicities in a Calu-3 Lung Epithelial Cell Model
Authors: Brillault Julien , De Castro Whocely Victor , Couet William
Published: October 2009

The transport characteristics of six fluoroquinolones (FQs) with various lipophilicities were compared in a Calu-3 cell model. For each FQ, an active polarized transport was observed in the direction of the apical side. However, the apparent permeability of FQs resulted from active transport and passive diffusion that were highly variable between compounds and mainly governed by lipophilicity. Therefore, active transport was predominant for compounds with relatively low lipophilicity but minor for FQs with higher lipophilicity.
Plasmid-Mediated Quinolone Resistance: a Multifaceted Threat
Authors: Strahilevitz Jacob , Jacoby George A. , Hooper David C. , Robicsek Ari
Published: October 2009

Although plasmid-mediated quinolone resistance (PMQR) was thought not to exist before its discovery in 1998, the past decade has seen an explosion of research characterizing this phenomenon. The best-described form of PMQR is determined by theqnrgroup of genes. These genes, likely originating in aquatic organisms, code for pentapeptide repeat proteins. These proteins reduce susceptibility to quinolones by protecting the complex of DNA and DNA gyrase or topoisomerase IV enzymes from the inhibitory effect of quinolones. Two additional PMQR mechanisms were recently described.aac(6′)-Ib-crencodes a variant aminoglycoside acetyltransferase with two amino acid alterations allowing it to inactivate ciprofloxacin through the acetylation of its piperazinyl substituent.oqxABandqepAencode efflux pumps that extrude quinolones. All of these genes determine relatively small increases in the MICs of quinolones, but these changes are sufficient to facilitate the selection of mutants with higher levels of resistance. The contribution of these genes to the emergence of quinolone resistance is being actively investigated. Several factors suggest their importance in this process, including their increasing ubiquity, their association with other resistance elements, and their emergence simultaneous with the expansion of clinical quinolone resistance. Of concern, these genes are not yet being taken into account in resistance screening by clinical microbiology laboratories.
Basic Concepts of Microarrays and Potential Applications in Clinical Microbiology
Authors: Miller Melissa B. , Tang Yi-Wei
Published: October 2009

The introduction of in vitro nucleic acid amplification techniques, led by real-time PCR, into the clinical microbiology laboratory has transformed the laboratory
detection
of viruses and select bacterial pathogens. However, the progression of the molecular diagnostic revolution currently relies on the ability to efficiently and accurately offer multiplex detection and characterization for a variety of infectious disease pathogens. Microarray analysis has the capability to offer robust multiplex detection but has just started to enter the diagnostic microbiology laboratory. Multiple microarray platforms exist, including printed double-stranded DNA and oligonucleotide arrays, in situ-synthesized arrays, high-density bead arrays, electronic microarrays, and suspension bead arrays. One aim of this paper is to review microarray technology, highlighting technical differences between them and each platform's advantages and disadvantages. Although the use of microarrays to generate gene expression data has become routine, applications pertinent to clinical microbiology continue to rapidly expand. This review highlights uses of microarray technology that impact diagnostic microbiology, including the detection and identification of pathogens, determination of antimicrobial resistance, epidemiological strain typing, and analysis of microbial infections using host genomic expression and polymorphism profiles.
Dengue Virus Pathogenesis: an Integrated View
Authors: Martina Byron E. E. , Koraka Penelope , Osterhaus Albert D. M. E.
Published: October 2009

Much remains to be learned about the pathogenesis of the different manifestations of dengue virus (DENV) infections in humans. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever (DHF), and eventually dengue shock syndrome (DSS). As both cell tropism and tissue tropism of DENV are considered major determinants in the pathogenesis of dengue, there is a critical need for adequate tropism assays, animal models, and human autopsy data. More than 50 years of research on dengue has resulted in a host of literature, which strongly suggests that the pathogenesis of DHF and DSS involves viral virulence factors and detrimental host responses, collectively resulting in abnormal hemostasis and increased vascular permeability. Differential targeting of specific vascular beds is likely to trigger the localized vascular hyperpermeability underlying DSS. A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk for development of severe disease.
Antibacterial-ResistantPseudomonas aeruginosa: Clinical Impact and Complex Regulation of Chromosomally Encoded Resistance Mechanisms
Authors: Lister Philip D. , Wolter Daniel J. , Hanson Nancy D.
Published: October 2009

Treatment of infectious diseases becomes more challenging with each passing year. This is especially true for infections caused by the opportunistic pathogenPseudomonas aeruginosa, with its ability to rapidly develop resistance to multiple classes of antibiotics. Although the import of resistance mechanisms on mobile genetic elements is always a concern, the most difficult challenge we face withP. aeruginosais its ability to rapidly develop resistance during the course of treating an infection. The chromosomally encoded AmpC cephalosporinase, the outer membrane porin OprD, and the multidrug efflux pumps are particularly relevant to this therapeutic challenge. The discussion presented in this review highlights the clinical significance of these chromosomally encoded resistance mechanisms, as well as the complex mechanisms/pathways by whichP. aeruginosaregulates their expression. Although a great deal of knowledge has been gained toward understanding the regulation of AmpC, OprD, and efflux pumps inP. aeruginosa, it is clear that we have much to learn about how this resourceful pathogen coregulates different resistance mechanisms to overcome the antibacterial challenges it faces.
A Thiolase of
Mycobacterium tuberculosis
Is Required for Virulence and Production of Androstenedione and Androstadienedione from Cholesterol
Authors: Nesbitt Natasha M. , Yang Xinxin , Fontán Patricia , Kolesnikova Irina , Smith Issar , Sampson Nicole S. , Dubnau Eugenie
Published: October 2009

Mycobacterium tuberculosis
, the causative agent of tuberculosis, is an intracellular pathogen that shifts to a lipid-based metabolism in the host. Moreover, metabolism of the host lipid cholesterol plays an important role in
M. tuberculosis
infection. We used transcriptional profiling to identify genes transcriptionally regulated by cholesterol and KstR (Rv3574), a TetR-like repressor. The
fadA5
(Rv3546) gene, annotated as a lipid-metabolizing thiolase, the expression of which is upregulated by cholesterol and repressed by KstR, was deleted in
M. tuberculosis
H37Rv. We demonstrated that
fadA5
is required for utilization of cholesterol as a sole carbon source in vitro and for full virulence of
M. tuberculosis
in the chronic stage of mouse lung infection. Cholesterol is not toxic to the
fadA5
mutant strain, and, therefore, toxicity does not account for its attenuation. We show that the wild-type strain, H37Rv, metabolizes cholesterol to androst-4-ene-3,17-dione (AD) and androsta-1,4-diene-3,17-dione (ADD) and exports these metabolites into the medium, whereas the
fadA5
mutant strain is defective for this activity. We demonstrate that FadA5 catalyzes the thiolysis of acetoacetyl-coenzyme A (CoA). This catalytic activity is consistent with a β-ketoacyl-CoA thiolase function in cholesterol β-oxidation that is required for the production of androsterones. We conclude that the attenuated phenotype of the
fadA5
mutant is a consequence of disrupted cholesterol metabolism that is essential only in the persistent stage of
M. tuberculosis
infection and may be caused by the inability to produce AD/ADD from cholesterol.
Characterization of the Highly Regulated Antigen BBA05 in the Enzootic Cycle of
Borrelia burgdorferi
Authors: Xu Haijun , He Ming , Pang Xiujuan , Xu Zao C. , Piesman Joseph , Yang X. Frank
Published: October 2009

Dramatic alteration of surface lipoprotein profiles is a key strategy that
Borrelia burgdorferi
, the Lyme disease pathogen, has evolved for adapting to the diverse environments of arthropod and mammalian hosts. Several of these differentially expressed lipoproteins have been shown to play important roles in the enzootic cycle of
B. burgdorferi
. The BBA05 protein is a previously identified putative lipoprotein (P55 or S1 antigen) that elicits antibody responses in mammals. Recent microarray analyses indicate that the BBA05 gene is differentially expressed by many environmental factors, including temperature. However, the role of the BBA05 protein in the life cycle of
B. burgdorferi
has not been elucidated. Here we show that expression of the BBA05 gene was exclusively induced in feeding nymphal ticks during the spirochetal transmission from ticks to mammals. Upon generating a BBA05 mutant in an infectious strain of
B. burgdorferi
, we showed that the BBA05 mutant remained capable of establishing infection in mice, being acquired by ticks, persisting through tick molting, and reinfecting new mammalian hosts. These results indicate that, despite being a highly conserved and regulated antigen, the BBA05 protein has a nonessential role in the transmission cycle of
B. burgdorferi
, at least in the animal model.
Smoking among rural and urban young women in China
Authors: Ho Michael G , Ma Shaojun , Chai Wanxing , Xia Wan , Yang Gonghuan , Novotny Thomas E
Published: October 2009

Methods

A survey of 11 095 urban and rural women attending high school or college, aged 14–24 years, in 6 Chinese provinces was conducted. Ever-smoking (ES), current smoking, established smoking and intention to smoke frequencies were calculated. Bivariate analyses were conducted to identify possible correlates of smoking, and those found to be significant at the p=0.1 level were included in a multivariate logistical regression model to obtain adjusted OR for correlates of ES.

Results

ES prevalence was 20.1%, with urban female students (UFS) at 22.0% and rural female students (RFS) at 19.0% (p<0.01). Established smoking prevalence was higher among UFS than RFS (2.4% vs 0.9%, p<0.01). Similarly, current smoking prevalence was higher among UFS than RFS (4.2% vs 1.9%, p<0.01). The intention to smoke prevalence was higher among UFS than RFS (3.5% vs 1.7%, p<0.01). The majority were aware that smoking was harmful to health, but were less aware of specific diseases associated with smoking. ES was associated with awareness of cigarettes made for women (OR, 1.66, 95% CI 1.49 to 1.86) and thinking that they were less harmful than other cigarettes (OR 1.54, 95% CI 1.33 to 1.79). The strongest correlate of ES was low refusal self-efficacy (OR 6.35, 95% CI 5.32 to 7.57).

Conclusions

This is the first report that having heard of women's cigarettes is a correlate of smoking among young Chinese women. ES among young Chinese women has increased in the last decade, and thus, specific prevention strategies need to be developed to prevent the tobacco epidemic from spreading among this vulnerable population.
Long-term declines in phosphorus export from forested catchments in south-central Ontario
Authors: Eimers M. Catherine , Watmough Shaun A. , Paterson Andrew M. , Dillon Peter J. , Yao Huaxia
Published: October 2009

Total phosphorus (TP) levels in many Canadian Shield lakes in central Ontario have declined over recent decades, despite increases in human activity in most watersheds. To investigate the contribution of changes in catchment export to long-term declines in lake TP, we examined temporal and spatial patterns in TP concentrations and export (1980–1981 to 2001–2002) across 11 subcatchments that drain into three lakes in which average ice-free TP levels have declined by approximately 35%. Annual stream export of TP decreased significantly by 30%–89% in eight of the 11 subcatchments, and decreases in export were driven by declines in TP concentration, not changes in stream flow. Annual average TP concentrations varied fivefold among adjacent subcatchments, and temporal patterns in annual average TP concentrations were poorly correlated. Seasonal patterns of TP concentration were most similar among streams in the spring (March–April–May), and TP export in the spring declined significantly in 10 of the 11 subcatchments. Because spring melt is the principal hydrologic event in these seasonally snow-covered basins, decreases in TP export during the spring were primarily responsible for declines observed in annual export. The drivers of changes in TP over time are unclear at this point but are the focus of current research.
Effects of predation from juvenile herring (Clupea harengus) on mortality rates of capelin (Mallotus villosus) larvae
Authors: Hallfredsson Elvar H. , Pedersen Torstein
Published: October 2009

Predation has been suggested as a cause of substantial mortality of fish larvae to the degree that it might influence recruitment. This field-based study concludes that juvenile herring ( Clupea harengus ) as small pelagic predator can significantly affect mortality rates of the planktonic larvae of capelin ( Mallotus villosus ) in the Barents Sea. Surveys were carried out in the summers of 2001 and 2003. In 2001, juvenile herring were widely distributed and overlapped with capelin larvae over a wide area, whereas in 2003, the herring were more aggregated. The study focused on predation in the areas of predator–prey overlap. Capelin larvae were observed in the herring stomachs at 11 of 24 stations and at 8 of 16 stations where herring were caught in 2001 and 2003, respectively. At those stations, an estimated 7.3% and 9.9% of the capelin larvae were eaten by herring per day in 2001 and 2003, respectively. Statistical models revealed that density of capelin larvae and copepods and occurrence of euphausiids in the stomachs affected the number of capelin larvae per predator stomach. A simplified model with only capelin larvae density as predictor was converted to a functional response relationship using an experimentally derived digestion rate estimate for capelin larvae in herring stomachs.
Limnological properties of permafrost thaw ponds in northeastern Canada
Authors: Breton Julie , Vallières Catherine , Laurion Isabelle
Published: October 2009

Arctic warming has recently accelerated, triggering the formation of thaw ponds and the mobilization of a carbon pool that has accumulated over thousands of years. A survey of 46 thaw ponds in the Canadian arctic and subarctic regions showed that these ecosystems have high concentrations of dissolved organic matter (DOM) and nutrients and are relatively productive. This activity was reflected in the optical properties of DOM that indicated a dominance of allochthonous sources but a significant contribution of low molecular weight compounds. Several subarctic ponds were stratified in summer, resulting in a hypoxic hypolimnion. Most ponds were supersaturated in CO2 and CH4, with higher gas concentrations in bottom waters. However, arctic thaw ponds colonized by benthic microbial mats showed lower CO2 concentrations, likely caused by active photosynthesis. CO2 was correlated with both the quantity and the optical properties of DOM, suggesting the significant role of dissolved compounds from melting organic soils and catchment vegetation on the balance between heterotrophy and autotrophy. The large variability observed in limnological properties of this series of ponds precludes generalisations about their role in greenhouse gas production. However, the fact that all thaw ponds were supersaturated in CH4 underscores the importance of estimating their global significance.
Behavioral thermoregulation and associated mortality trade-offs in migrating adult steelhead (Oncorhynchus mykiss): variability among sympatric populations
Authors: Keefer Matthew L. , Peery Christopher A. , High Brett
Published: October 2009

We used radiotelemetry to assess thermoregulatory behaviors for 14 populations (n = 3985) of adult summer steelhead ( Oncorhynchus mykiss ) as they passed through the Columbia River migration corridor. Steelhead use of small cool-water tributaries (“thermal refugia”) rapidly increased when the Columbia River reached a temperature threshold of about 19 °C. When main stem temperatures were warmest (i.e., >21 °C), more than 70% of the tagged fish used refugia sites and these fish had median refugia residence times of 3–4 weeks. Thermoregulatory responses were similar across populations, but there were large among-population differences in the incidence and duration of refugia use likely linked to population-specific migration timing patterns. In survival analyses using 1285 known-origin steelhead, fish that used thermal refugia were significantly less likely to survive to natal basins, were harvested at relatively high rates in refugia tributaries, and had greater unknown mortality in the main stem. These results highlight the trade-off between the presumed physiological benefits of thermal refugia use and a likely increase in harvest and other mortality risks that arise when preferred thermal habitats are severely constricted.
Light-dependent predation by the invertebrate planktivore Bythotrephes longimanus
Authors: Pangle Kevin L. , Peacor Scott D.
Published: October 2009

We evaluated predation by the invasive invertebrate planktivore Bythotrephes longimanus on a Lake Michigan prey assemblage as a function of light intensity. Daphnia mendotae was the only prey type significantly reduced and light intensity strongly affected this reduction. Specifically, Bythotrephes consumption of D. mendotae was not detected under low light intensity (<1 µmol·m–2·s–1) but increased with greater light intensity and leveled off under high light intensity (>100 µmol·m–2·s–1) at which point Bythotrephes ingestion rate was 2.3 Daphnia per hour. These results indicate that Bythotrephes predation is more sensitive to light than previously thought, a discrepancy that can be explained after considering the ability of D. mendotae to detect Bythotrephes’ hydromechanic disturbance. The observed effect of light intensity on Bythotrephes predation is more like that of planktivorous fish than that of other previously studied invertebrate planktivores. Our findings elucidate the role that Bythotrephes plays in the food web and provide a novel explanation for its tendency to invade lakes of high water clarity. The importance of light-dependent predation found here may extend to other visually oriented predatory cladocerans.
Highly presumptive identification of bacterial isolates associated with the recent Canada-wide mastitis epizootic as Nocardia farcinica
Authors: Manninen K. I. , Smith R. A. , Kim L. O.
Published: October 2009

A highly presumptive identification of Nocardia farcinica was made of 47 bacterial isolates. Fifteen isolates from Alberta, 9 from Ontario, and 2 each from New Brunswick, Newfoundland, and Nova Scotia were from clinical cases involved in the Canadian mastitis epizootic. Seventeen additional isolates from Alberta were recovered from farm milk bulk tanks from herds found to have cows involved in the epizootic. All isolates were shown by high-performance liquid chromatography to possess mycolic acids of a size consistent with the genus Nocardia. All isolates were resistant to a concentration of 5 μg/mL of mitomycin C. Forty-five isolates grew well and 2 showed reduced growth in the presence of 50 μg/mL of kanamycin acid sulfate. Forty-six isolates were resistant to 5-fluorouracil at a concentration of 20 μg/mL. All isolates were resistant to lysozyme. Resistance to these compounds supported the placement of the isolates in the genus Nocardia. Thirty-five isolates produced strong β-galactosidase reactions and 12 showed weak reactions. The demonstration of β-galactosidase activity further supports the identification of the isolates as nocardiae. Attempts to identify the bacteria to species by high-performance liquid chromatography of mycolic acid esters were frustrated, since two species of Nocardia were found to have indistinguishable mycolic acid patterns. The physiological and growth characteristics of the isolates were consistent with Nocardia farcinica.Key words: Nocardia farcinica, mastitis, mycolic acids, high-performance liquid chromatography.
Potential for carboxylation–dehydroxylation of phenolic compounds by a methanogenic consortium
Authors: Bisaillon Jean-Guy , Lépine François , Beaudet Réjean , Sylvestre Michel
Published: October 2009

An anaerobic consortium that carboxylated and dehydroxylated phenol to benzoate, and 2-cresol to 3-methylbenzoic acid, under methanogenic conditions was studied. Phenol induced this transformation activity. Addition of 4-hydroxypyridine or an increase in the concentration of proteose peptone to 0.5% (w/v) delayed the transformation. Phenol enhanced the rate of transformation of 2-cresol whereas 2-cresol delayed the transformation of phenol. Phenols with ortho-substitutions (chloro-, fluoro-, bromo-, hydroxyl-, amino-, or carboxyl-) were transformed to meta-substituted benzoic acids. However, meta- and para-substituted phenols (cresols, fluorophenols, and chlorophenols) were not transformed. Phenol was most rapidly metabolized, followed by catechol, 2-cresol, 2-fluorophenol, 2-aminophenol, 2-chlorophenol, 2-hydroxybenzoic acid, and 2-bromophenol. The consortium O-demethylated anisole to phenol and 2-methoxyphenol to catechol, and oxidized 2-hydroxybenzyl alcohol to 2-hydroxybenzoic acid. Aniline, 2-ethylphenol, 2-hydroxypyridine, 2-acetamidophenol, 2,6-dimethylphenol, 2-phenylphenol, and 1-naphthol were not metabolized.Key words: phenolic compounds, methanogenic consortium, carboxylation–dehydroxylation.
Insertion sequence elements in Bacillus thuringiensis subsp. darmstadiensis
Authors: Ryan Margret , Johnson Jerry D. , Bulla Jr. Lee A.
Published: October 2009

Two variants of insertion sequence IS231, named IS231G and H, were isolated from Bacillus thuringiensis subsp. darmstadiensis 73-E-10-2 (BTD2), an isolate toxic to dipteran insects, and characterized by DNA sequence analysis. They are encoded consecutively as direct repeats on an EcoRI fragment of 5.6 kilo base pairs. Direct tandem repeats of IS231 elements have not been previously reported. Both elements are closely related to other members of the IS231 family that have been isolated from B. thuringiensis strains toxic to lepidopteran as well as to dipteran insects. A close correlation exists between the evolutionary relationships of the IS231 sequences determined to date and the toxicity spectrum of the host cell. Probing of BTD2 DNA with a radiolabeled IS231G fragment demonstrated that IS231 elements are located on 55- and 34-MDa plasmids as well as on chromosomal DNA. Chromosomal DNA, but not plasmids, from BTD2 also hybridizes to another, unrelated insertion sequence, IS240, from B. thuringiensis subsp. israelensis, an isolate toxic to dipteran insects. BTD2, therefore, contains IS elements once thought to reside exclusively in either dipteran- or lepidopteran-specific subspecies of B. thuringiensis.Key words: IS231, IS240, mobile elements.
The 73-kb pIAA plasmid increases competitive fitness of Pseudomonas syringae subspecies savastanoi in oleander
Authors: Silverstone Sara E. , Gilchrist David G. , Bostock Richard M. , Kosuge Tsune
Published: October 2009

Pseudomonas syringae subsp. savastanoi causes tumors on olive and oleander by producing the plant growth regulators indoleacetic acid (IAA) and cytokinins following infection of the plant. The contribution of IAA production to the ability of P. syringae subsp. savastanoi to grow and survive in oleander leaf tissue was studied. Bacterial strains differing only with respect to IAA production were characterized. Growth and survival of wild-type and two mutant strains of P. syringae subsp. savastanoi in oleander leaf tissue were monitored by weekly colony counts and IAA plate assays. Growth rate of the three strains in culture and in planta did not differ significantly. However, the wild-type strain reached a higher population density and maintained its maximum density at least 9 weeks longer than either mutant population. An insertion mutant containing the IAA plasmid (pIAA), but incapable of IAA production, did not maintain a higher population density than a strain cured of the IAA plasmid. The pIAA-cured strain maintained a higher population density when coinoculated with an IAA-producing strain than when inoculated alone. These results suggest that IAA production may contribute to the fitness of P. syringae subsp. savastanoi in oleander tissue and that the iaa operon alone may be responsible for the competitive advantage of cells harboring pIAA.Key words: indoleacetic acid, bacterial ecology.
Phylogenetic grouping and identification of Rhizobium isolates on the basis of random amplified polymorphic DNA profiles
Authors: Dooley John J. , Harrison Stephen P. , Mytton Lance R. , Dye Malcolm , Cresswell Ann , Skot Leif , Beeching John R.
Published: October 2009

Through the use of a single, random 15mer as a primer, between 1 and 12 DNA amplification products were obtained per strain from a selection of 84 Rhizobium and Bradyrhizobium isolates. A principal-coordinate analysis was used to analyse the resulting amplified DNA profiles and it was possible to assign isolates to specific groupings. Within the species Rhizobium leguminosarum, the biovar phaseoli formed a distinct group from the other biovars of the species, viciae and trifolii, which grouped together. Isolates of Rhizobium meliloti and Bradyrhizobium species formed their own clear, specific groups. Although it was possible to identify individual isolates on the basis of differences in their amplified DNA profiles, there was evidence that some amplified segments were conserved among individuals at the biovar and species levels.Key words: Rhizobium, DNA amplification, random primers.
Persistence of a surrogate for a genetically engineered cellulolytic microorganism and effects on aquatic community and ecosystem properties: mesocosm and stream comparisons
Authors: Bott Thomas L. , Kaplan Louis A.
Published: October 2009

Our research objectives were to (i) determine the persistence of an introduced surrogate (Cellulomonas sp. NRC 2406) for a genetically engineered microorganism in sediments, growths of Cladophora glomerata (Chlorophyta), and leaf packs, (ii) test community and ecosystem structural and functional responses to the introduced bacteria, and (iii) evaluate the utility of flowing water mesocosms as tools for assessing the fates and effects of introduced bacteria in streams. Cellulomonas sp. densities were determined using fluorescent antibodies; maxima were ≤ 1% of the total bacterial community in each habitat in two experiments, and ≈25% of total densities in leaf packs in a third experiment. Densities declined from postinoculation maxima faster in sediments than in C. glomerata growths and leaf packs. Cellulomonas sp. persisted in leaf packs at densities significantly greater than background. Cellulomonas sp. had no statistically significant effects on primary productivity, community respiration, assimilation ratios, photosynthesis/respiration (P/R) ratios, bacterial productivity, and leaf litter decomposition rates. Cellulase concentrations were positively correlated with Cellulomonas sp. densities ≥ 7 × 108 cells/g dry mass in fresh leaf litter for 2 days following exposure. Total bacterial densities, algal biomass, and total viable biomass sometimes differed between control and experimental systems, but differences were not related to Cellulomonas sp. introduction. Mesocosms were good tools for studying bacterial population dynamics in leaf litter and physiological aspects of litter degradation, but they were less well suited to measuring losses of litter mass and cellulose because physical abrasion during storms accelerated those processes in the field.Key words: bacterial population dynamics, mesocosms, streams, introduced bacteria, Cellulomonas sp., litter decomposition.
Esterase diversity among 46 Frankia strains isolated from Casuarina equisetifolia in West Africa
Authors: Maggia Laurent , Prin Yves , Picard Bertrand , Goullet Philippe
Published: October 2009

Forty-six Frankia strains isolated from nodules of five Casuarina equisetifolia stands throughout Senegal and Gambia were analyzed for their enzyme electrophoretic profiles and compared with six collection strains. These strains were classified into 14 electrotypes, according to their esterase patterns. One or two electrotypes were predominant in each investigation site whereas other electrotypes corresponded to only one strain each. Esterase electrophoretic polymorphism evidenced heterogeneity of a restricted population of Frankia strains belonging to a single genomic species and indicated the high discriminating power of these enzymes for the study of the ecological repartition of Frankia strains in a tropical region.Key words: Casuarina equisetifolia, Frankia, Senegal, enzyme electrophoresis.