Threshold Heat-Flux Reduction by Near-Resonant Energy Transfer.

Near-resonant energy transfer to large-scale stable modes is shown to reduce transport above the linear critical gradient, contributing to the onset of transport at higher gradients. This is demonstrated for a threshold fluid theory of ion temperature gradient turbulence based on zonal-flow-catalyzed transfer. The heat flux is suppressed above the critical gradient by resonance in the triplet correlation time, a condition enforced by the wave numbers of the interaction of the unstable mode, zonal flow, and stable mode.

Functional Evaluation of Three Manure-Borne Indicator Bacteria Release Models with Multiyear Field Experiment Data.

Modeling the fate and transport of Escherichia coli is of substantial interest because of how this organism serves as an indicator of fecal contamination in microbial water quality assessment. The efficacy of models used to assess the export of E. coli from agricultural fields is dependent, in part, on submodels they utilize to simulate E. coli release from land-applied manure and animal waste. Although several release submodels have been proposed, they have only been evaluated and compared with data from laboratory or small plot E. coli release experiments. Our objective was to evaluate and compare performances of three manure-borne bacteria release submodels at field-scale: exponential release (EM), two-parametric Bradford and Schijven (B-S), and two-parametric Vadas-Kleinman-Sharpley (VKS); each was independently incorporated and tested as a submodel within the export model KINEROS2/STWIR, using E. coli. Dairy manure was uniformly applied via surface broadcasting once a year for six consecutive years on a 0.28 ha experimental field site. Two irrigation events followed each application: the first immediately followed the initial application and the second occurred one week later. Manure and soil samples were collected before and after irrigation, respectively, and manure, soil, and edge-of-field runoff samples were analyzed for E. coli. Model performance was evaluated with the Akaike criterion, coefficients of determination (R2), and root mean squared errors (RMSE) values. The percentage of exported manure-borne E. coli varied from 0.1% to 10% in most cases, generally reflecting the lag time between initiation of irrigation and initiation ofedge-of-field runoff. The export model performed better when using the VKS submodel which was preferred in 55% of cases. The B-S and EM submodels were preferred in 27% and 18% of cases, respectively. Two-parametric submodels were ultimately preferred over the single parameter submodel.

Extracting the turbulent flow-field from beam emission spectroscopy images using velocimetry.

The 2D turbulent E × B flow-field is inferred from density fluctuation images obtained with the beam emission spectroscopy diagnostic on DIII-D using the orthogonal dynamic programming velocimetry algorithm. A synthetic turbulence model is used to test the algorithm and optimize it for measuring zonal flows. Zonal flow measurements are found to require a signal-to-noise ratio above ∼10 and a zonal flow wavelength longer than ∼2 cm. Comparison between the velocimetry-estimated flow-field and the E × B flow-field using a nonlinear gyrokinetic GENE simulation finds that the flow-fields have identical spatial structure and differ only by the mean turbulence phase velocity, which is spatially uniform in this flux tube simulation.

Nonlinear Electromagnetic Stabilization of Plasma Microturbulence.

The physical causes for the strong stabilizing effect of finite plasma ß on ion-temperature-gradient-driven turbulence, which far exceeds quasilinear estimates, are identified from nonlinear gyrokinetic simulations. The primary contribution stems from a resonance of frequencies in the dominant nonlinear interaction between the unstable mode, the stable mode, and zonal flows, which maximizes the triplet correlation time and therefore the energy transfer efficiency. A modification to mixing-length transport estimates is constructed, which reproduces nonlinear heat fluxes throughout the examined ß range.

Osteoporosis in the at-risk asthmatic.

The effect of inhaled glucocorticosteroids (ICS) on bone metabolism and subsequent osteoporosis is controversial. Explanations for this controversy include various study designs, duration of use, outcome measures, and population demographics of research studies with intranasal or inhalational ICS. Patients with poorly controlled asthma are at greatest risk of osteoporosis because they are commonly treated with intermittent or continuous systemic corticosteroids (SCS) or high-dose ICS. A 45-year-old Caucasian woman presents with moderate-to-severe asthma with frequent albuterol use and nighttime awakenings at least once weekly. She is on fluticasone/salmeterol 500/50 µg one inhalation twice daily and montelukast 10 mg/day. She requires prednisone 15 mg three times per day for 5 days up to three times a year. Is this patient at greater risk of osteopenia, characterized by a T-score between -1.0 and -2.5, and subsequent osteoporosis and an increased risk of fractures? If she has osteopenia, should she be treated with a bisphosphonate? The risk of osteoporosis and fracture increases significantly with frequent administration of SCS, and patients on such medications should undergo preventative measures and treatment. This study discuses factors that contribute to an increased risk of osteoporosis/osteopenia in patients with asthma and suggests recommendations based on the current literature.

Comparing temperature effects on Escherichia coli, Salmonella, and Enterococcus survival in surface waters.

UNLABELLED: The objective of this study was to compare dependency of survival rates on temperature for indicator organisms Escherichia coli and Enterococcus and the pathogen Salmonella in surface waters. A database of 86 survival datasets from peer-reviewed papers on inactivation of E. coli, Salmonella and Enterococcus in marine waters and of E. coli and Salmonella in lake waters was assembled. The Q10 model was used to express temperature effect on survival rates obtained from linear sections of semi-logarithmic survival graphs. Available data were insufficient to establish differences in survival rates and temperature dependencies for marine waters where values of Q10  = 3 and a survival rate of 0·7 day(-1) could be applied. The Q10 values in lake waters were substantially lower in marine waters, and Salmonella inactivation in lake water was, on average, twice as fast as E. coli; data on E. coli substantially outnumber data on Enterococcus and Salmonella. The relative increase in inactivation with increase in temperature is higher in marine waters than lake water, and differences in inactivation between Salmonella and E. coli at a given temperature were significant in lake water but not in marine waters. SIGNIFICANCE AND IMPACT OF THE STUDY: Microbiological quality of surface waters is of paramount importance for public health. The novelty of this work is using a large compendium of published data to develop the first comparison of temperature effects on survival of the pathogen Salmonella and water quality indicator micro-organisms Escherichia coli and Enterococcus in natural waters. The existing relatively large body of knowledge on E. coli survival appears to be useful to assess the effect of temperature on survival of Salmonella. Moreover, results of this work constitute an essential input in models to support environmental management decisions on the use of surface water sources in agriculture, aquaculture and recreation.

Escherichia coli survival in waters: temperature dependence.

Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q10 model. This suggestion was made 34 years ago based on 20 survival curves taken from published literature, but has not been revisited since then. The objective of this study was to re-evaluate the accuracy of the Q10 equation, utilizing data accumulated since 1978. We assembled a database of 450 E. coli survival datasets from 70 peer-reviewed papers. We then focused on the 170 curves taken from experiments that were performed in the laboratory under dark conditions to exclude the effects of sunlight and other field factors that could cause additional variability in results. All datasets were tabulated dependencies "log concentration vs. time." There were three major patterns of inactivation: about half of the datasets had a section of fast log-linear inactivation followed by a section of slow log-linear inactivation; about a quarter of the datasets had a lag period followed by log-linear inactivation; and the remaining quarter were approximately linear throughout. First-order inactivation rate constants were calculated from the linear sections of all survival curves and the data grouped by water sources, including waters of agricultural origin, pristine water sources, groundwater and wells, lakes and reservoirs, rivers and streams, estuaries and seawater, and wastewater. Dependency of E. coli inactivation rates on temperature varied among the water sources. There was a significant difference in inactivation rate values at the reference temperature between rivers and agricultural waters, wastewaters and agricultural waters, rivers and lakes, and wastewater and lakes. At specific sites, the Q10 equation was more accurate in rivers and coastal waters than in lakes making the value of the Q10 coefficient appear to be site-specific. Results of this work indicate possible sources of uncertainty to be accounted for in watershed-scale microbial water quality modeling.

Bacterial infections of Chinook salmon, Oncorhynchus tshawytscha (Walbaum), returning to gamete collecting weirs in Michigan.

Herein, we describe the prevalence of bacterial infections in Chinook salmon, Oncorhynchus tshawytscha (Walbaum), returning to spawn in two tributaries within the Lake Michigan watershed. Ten bacterial genera, including Renibacterium, Aeromonas, Carnobacterium, Serratia, Proteus, Pseudomonas, Hafnia, Salmonella, Shewanella and Morganella, were detected in the kidneys of Chinook salmon (n = 480) using culture, serological and molecular analyses. Among these, Aeromonas salmonicida was detected at a prevalence of ∼15%. Analyses revealed significant interactions between location/time of collection and gender for these infections, whereby overall infection prevalence increased greatly later in the spawning run and was significantly higher in females. Renibacterium salmoninarum was detected in fish kidneys at an overall prevalence of >25%. Logistic regression analyses revealed that R. salmoninarum prevalence differed significantly by location/time of collection and gender, with a higher likelihood of infection later in the spawning season and in females vs. males. Chi-square analyses quantifying non-independence of infection by multiple pathogens revealed a significant association between R. salmoninarum and motile aeromonad infections. Additionally, greater numbers of fish were found to be co-infected by multiple bacterial species than would be expected by chance alone. The findings of this study suggest a potential synergism between bacteria infecting spawning Chinook salmon.

High prevalence of buccal ulcerations in largemouth bass, Micropterus salmoides (Centrarchidae) from Michigan inland lakes associated with Myzobdella lugubris Leidy 1851 (Annelida: Hirudinea).

Widespread mouth ulcerations were observed in largemouth bass collected from eight inland lakes in the Lower Peninsula of Michigan during the summer months of 2002 and 2003. These ulcerations were associated with, and most likely caused by, leech parasitism. Through the use of morphological dichotomous keys, it was determined that all leeches collected are of one species: Myzobdella lugubris. Among the eight lakes examined, Lake Orion and Devils Lake had the highest prevalence of leech parasitism (34% and 29%, respectively) and mouth ulcerations (53% and 68%, respectively). Statistical analyses demonstrated that leech and ulcer prevalence varied significantly from one lake to the other. Additionally, it was determined that the relationship between the prevalence of ulcers and the prevalence of leech attachment is significant, indicating that leech parasitism is most likely the cause of ulceration. The ulcers exhibited deep hemorrhagic centers and raised irregular edges. Affected areas lost their epithelial lining and submucosa, with masses of bacteria colonizing the damaged tissues. Since largemouth bass is a popular global sportfish and critical to the food web of inland lakes, there are concerns that the presence of leeches, damaged buccal mucosa, and general unsightliness may negatively affect this important sportfishery.

Training program in the field of addiction medicine - an experience of learning while abroad.

This paper illustrates the training program in the field of Addiction Medicine designed for primary care doctors by the Department of General Practice, School of Primary Care at Monash University in Melbourne. The nine month program was based around coursework, field visits and clinical observations. There were five modules that were completed and passed, twenty six Continuous Medical Education sessions attended, twenty nine field visits on Drug & Alcohol services, forty seven clinical visits and a total of three hundred and sixty clinical observations made. The comprehensive training program has benefited the first author in several ways to improve the Drugs & Alcohol services in Malaysia.

Hepatitis B immunity in a population of drug and alcohol users.

The objective of this study was to determine the level of immunity from Hepatitis B infection in an Australian population of drug and alcohol users, and the validity of self-reported immune status. A cross-sectional survey was employed of drug and alcohol users presenting for treatment, who were clients of De Paul House, a community-based drug and alcohol withdrawal service in Victoria. Outcome measures were: hepatitis B serology and personal reports of hepatitis B immunity. A total of 118 people were enrolled; 22% were injecting drug users and 48% reported past injecting drug use, while 55% were alcohol users; 51% had no general practitioner; 73% of participants were unaware of whether they were protected from hepatitis B infection, while 19.5% believed they were protected. However, serology demonstrated that 52.2% of those who believed they were protected were not immune. Only 21% of participants were immune. This is the first study in an Australian setting since the 1970s to examine the effectiveness of vaccination targeted to this population, and demonstrates low rates of immunity. New strategies are needed to deliver vaccination to this group. These will need to take account of the often chaotic nature of their lives, the poor validity of self-reported immunity, and the lack of primary care links.

Isolation of viral haemorrhagic septicaemia virus from muskellunge, Esox masquinongy (Mitchill), in Lake St Clair, Michigan, USA reveals a new sublineage of the North American genotype.

Viral haemorrhagic septicaemia virus (VHSV) was isolated from muskellunge, Esox masquinongy (Mitchill), caught from the NW portion of Lake St Clair, Michigan, USA in 2003. Affected fish exhibited congestion of internal organs; the inner wall of the swim bladder was thickened and contained numerous budding, fluid-filled vesicles. A virus was isolated using fish cell lines inoculated with a homogenate of kidney and spleen tissues from affected fish. Focal areas of cell rounding and granulation appeared as early as 24 h post-inoculation and expanded rapidly to destroy the entire cell sheet by 96 h. Electron microscopy revealed virions that were 170-180 nm in length by 60-70 nm in width having a bullet-shaped morphology typical of rhabdoviruses. The virus was confirmed as VHSV by reverse transcriptase-polymerase chain reaction. Sequence analysis of the entire nucleoprotein and glycoprotein genes revealed the virus was a member of the North American genotype of VHSV; however, the isolate was sufficiently distinct to be considered a separate sublineage, suggesting its origin may have been from marine species inhabiting the eastern coastal areas of the USA or Canada.

Substance misuse in first-episode psychosis: 15-month prospective follow-up study.

BACKGROUND: Well-designed prospective studies of substance misuse in first-episode psychosis can improve our understanding of the risks associated with comorbid substance misuse and psychosis. AIMS: To examine the potential effects of substance misuse on in-patient admission and remission and relapse of positive symptoms in first-episode psychosis. METHOD: The study was a prospective 15-month follow-up investigation of 103 patients with first-episode psychosis recruited from three mental health services. RESULTS: Substance misuse was independently associated with increased risk of in-patient admission, relapse of positive symptoms and shorter time to relapse of positive symptoms after controlling for potential confounding factors. Substance misuse was not associated with remission or time to remission of positive symptoms. Heavy substance misuse was associated with increased risk of in-patient admission, relapse and shorter time to relapse. CONCLUSIONS: Substance misuse is an independent risk factor for a problematic recovery from first-episode psychosis.

Assessment of methods of destruction of Syphacia muris eggs.

An investigation was performed to identify methods suitable for decontamination of equipment being transferred from a facility contaminated with Syphacia muris to a new facility. Perianal samples were taken on clear sticky tape from rats known to be infected with S. muris. Tapes and attached worm eggs were treated with ethylene oxide, formaldehyde fumigation, potassium peroxysulphate, chlorine dioxide and didecyl di-methyl ammonium chloride, chlorine dioxide, alcohol/chlorhexidine, 100 degrees C dry heat for 30 min, ultraviolet light (UV), or left for 4 weeks at room temperature. The subsequent viability of the eggs was compared to untreated control samples. Heat and ethylene oxide produced a 100% kill rate of S. muris eggs. Formaldehyde gas and chlorine dioxide treatments showed marked effectiveness, with the number of eggs killed at 94% and 96%, respectively, while the other agents showed less efficacy (36-78% eggs killed). The percentage of eggs not hatching in the controls was 21%. Since so few agents were effective against S. muris eggs, care should be taken when choosing a method for decontaminating a facility.

Extended acclimatization is required to eliminate stress effects of periodic blood-sampling procedures on vasoactive hormones and blood volume in beagle dogs.

Important in all experimental animal studies is the need to control stress stimuli associated with environmental change and experimental procedures. As the stress response involves alterations in levels of vasoactive hormones, ensuing changes in cardiovascular parameters may confound experimental outcomes. Accordingly, we evaluated the duration required for dogs (n = 4) to acclimatized to frequent blood sampling that involved different procedures. On each sampling occasion during a 6-week period, dogs were removed from their pen to a laboratory area and blood was collected either by venepuncture (days 2, 15, 34, 41) for plasma renin activity (PRA), epinephrine (EPI), norepinephrine, aldosterone, insulin, and atrial natriuretic peptide, or by cannulation (dogs restrained in slings; days 1, 8, 14, 22, 30, 33, 37, 40) for determination of haematocrit (HCT) alone (days 1 to 22) or HCT with plasma volume (PV; days 30 to 40). PRA was higher on days 2 and 15 compared with days 34 and 41 and had decreased by up to 48% by the end of the study (day 41 vs day 15; mean/SEM: 1.18/0.27 vs 2.88/0.79 ng ANG I/ml/h, respectively). EPI showed a time-related decrease from days 2 to 34, during which mean values had decreased by 51% (mean/SEM: 279/29 vs 134/20.9 pg/ml for days 2 and 34, respectively), but appeared stable from then on. None of the other hormones showed any significant variability throughout the course of the study. HCT was relatively variable between days 1 to 22 but stabilized from day 30, after which all mean values were approximately 6% lower than those between days 1 and 8. We conclude that an acclimatization period of at least 4 weeks is required to eliminate stress-related effects in dogs associated with periodic blood sampling.

LAAM maintenance vs methadone maintenance for heroin dependence.

BACKGROUND: LAAM and methadone are both full mu opiate agonists and have been shown to reduce dependence on heroin when given continuously under supervised dosing conditions. LAAM has a long duration of action requiring dosing every two or three days compared to methadone which requires daily dosing. LAAM is not as widely available internationally as methadone, and may be withdrawn from the market following ten cases of life-threatening cardiac arrhythmias and an association with QT prolongation. OBJECTIVES: To compare the efficacy and acceptability of LAAM maintenance with methadone maintenance in the treatment of heroin dependence. SEARCH STRATEGY: We searched MEDLINE (January 1966 to August 2000), PsycINFO (1887 to August 2000), EMBASE (January 1985 to August 2000), and the Cochrane Controlled Trials Register (Issue 2 2000). In addition we hand searched NIDA monographs until August 2000 and searched reference lists of articles. SELECTION CRITERIA: All randomised controlled trials, controlled clinical trials and controlled prospective studies comparing LAAM and methadone maintenance for the treatment of heroin dependence and measuring outcomes of efficacy or acceptability were included. DATA COLLECTION AND ANALYSIS: Data on retention in treatment, heroin use, side-effects and mortality were collected by two reviewers independently. A meta-analysis was performed using RevMan. Discrepancies were resolved by consensus. MAIN RESULTS: Eighteen studies, (15 RCTs, 3 Controlled prospective studies) met the inclusion criteria for the review. Three were excluded from the meta-analysis due to lack of data on retention, heroin use or mortality. Cessation of allocated medication (11 studies, 1473 participants) was greater with LAAM than with methadone, (RR 1.36, 95%CI 1.07-1.73, p=0.001, NNT=7.7 (or 8)). Non-abstinence was less with LAAM (5 studies, 983 participants; RR 0.81, 95%CI 0.72-0.91, p=0.0003, NNT=9.1 (or 10)). In 10 studies (1441 participants) there were 6 deaths from a range of causes, 5 in participants assigned to LAAM (RR 2.28 (95%CI 0.59-8.9, p=0.2). other relevant outcomes, such as quality of life and criminal activity could not be analysed because of lack of information in the primary studies. REVIEWER'S CONCLUSIONS: LAAM appears more effective than methadone at reducing heroin use. More LAAM patients than methadone ceased their allocated medication during the studies, but many transferred to methadone and so the significance of this is unclear. There was no difference in safety observed, although there was not enough evidence to comment on uncommon adverse events.

Naltrexone, a relapse prevention maintenance treatment of alcohol dependence: a meta-analysis of randomized controlled trials.

The objective of this study was to review the evidence for the efficacy and toxicity of naltrexone, a treatment of alcohol dependence. A systematic review and meta-analysis of randomized controlled trials of naltrexone used in the treatment of alcohol dependence was conducted. We searched MEDLINE, EMBASE, PsychLIT and the Cochrane Controlled Trials Registry for articles published between 1976 to January 2001. The manufacturer of naltrexone was asked to submit additional complete trial reports not in the literature. We analysed data from seven studies that compared naltrexone to placebo. The meta-analysis of benefit indicates that naltrexone is superior to placebo. Subjects treated with naltrexone experience significantly fewer episodes of relapse, and significantly more remain abstinent when compared to placebo-treated subjects [risk difference of relapse rates = -14% [95% confidence interval (CI): -23%, -5%]; and risk difference of abstinence rates = 10% (95% CI: 4%, 16%)] after 12 weeks of treatment. The naltrexone-treated subjects also consume significantly less alcohol over the study period than do placebo-treated subjects. There is no significant difference between naltrexone and placebo in terms of the number of subjects with at least one adverse event or the number of subjects who discontinued the trial due to an adverse event.

Prevalence of psychiatric disorder in a methadone maintenance population.

OBJECTIVE: The objective of this study was to examine the prevalence of psychiatric disorders in a group of patients who had recently entered a methadone maintenance programme. METHOD: A total of 62 patients were interviewed using the Composite International Diagnostic Interview (CIDI) within 6 months of commencing methadone maintenance. The CIDI was used to establish symptoms of psychiatric illness at interview and in the 12 months prior. RESULTS: In the 12 months prior to interview, 76% of the sample fulfilled ICD-10 criteria for a psychiatric disorder other than substance-use disorder. Over half of the group interviewed fulfilled ICD-10 criteria for an affective disorder, two-thirds fulfilled criteria for an anxiety disorder and just under half fulfilled diagnostic criteria for both an affective disorder and an anxiety disorder in the 12 months prior to interview. At the time of interview, 19% fulfilled ICD-10 diagnostic criteria for a moderate or severe affective disorder. Seventy per cent of males and 89% of females interviewed had a comorbid psychiatric illness. In 71% of the group who had a comorbid psychiatric illness, the onset of psychiatric symptomatology was reported to predate the use of heroin. CONCLUSION: The prevalence of psychiatric disorder is up to 10 times higher in the population on methadone maintenance than in the general population and is two to three times higher than that found in community surveys of those with a substance-use disorder. These results are consistent with earlier findings and have implications for service planning.

Validation of the doctor-patient communication component of the Educational Commission for Foreign Medical Graduates Clinical Skills Assessment.

BACKGROUND: The pivotal role of doctor-patient communication in effective health care delivery led the Educational Commission for Foreign Medical Graduates (ECFMG) to incorporate the assessment of interpersonal skills and spoken English proficiency into its Clinical Skills Assessment (CSA). Furthermore, it was decided that to pass the CSA, a candidate would need to meet or surpass defined performance standards for doctor-patient communication as a discrete component. This requirement, among others, is designed to ensure the readiness of graduates of foreign medical schools (FMGs) to enter postgraduate medical education programmes in the United States. OBJECTIVE: The primary focus of this study was to determine the extent to which performance in a simulated testing environment is related to performance in the clinical setting. METHOD: Nurses were trained to rate the communication skills of residents from the patient's perspective. A total of 43 first-year residents were evaluated. The survey ratings (n=225) were compared with the residents' CSA communication scores. RESULTS: Corrected correlations between CSA ratings and those obtained from nurses ranged from 0.61 to 0.73. CONCLUSION: This study provides evidence for the validity of the communication ratings provided by standardized patients. The reasonably strong associations between ratings obtained during testing and those obtained through observation of 'real' patient interactions suggest that external observers can provide accurate evaluations of doctor-patient communication.