Occupational Health and Well-being Questionnaire (OHWQ): an instrument to assess psychosocial risk and protective factors in the workplace.

OBJECTIVES: Psychosocial stressors at work have been identified as significant risk factors for several mental and physical health problems. These stressors must be compensated by psychosocial resources to prevent or reduce adverse effects on health. Questionnaires measuring these stressors and resources already exist, but none integrate digital stress, ethical culture, and psychosocial safety climate; factors that are increasingly linked to workers' health. This study aims to develop and establish the psychometric properties of one of the most comprehensive instruments measuring the psychosocial work environment to date: the Occupational Health and Well-being Questionnaire (OHWQ). STUDY DESIGN: A cross-sectional validation study is proposed to develop the OHWQ and document its psychometric properties. METHODS: The OHWQ was developed from validated instruments to which new items were added. The questionnaire includes psychosocial dimensions, along with indicators of psychological distress, musculoskeletal disorders, and well-being. It was administered to a sample of 2770 participants from a population working in the academic field. Exploratory and confirmatory factor analyses and the calculation of Cronbach's α coefficient were used to identify the variables, items, and, dimensions of the OHWQ and to document its main psychometric properties. RESULTS: The acceptability of the measurement model was evaluated by the reliability of the items, internal consistency between the items, and the convergent and discriminant validity. Construct validity was assessed using exploratory and confirmatory factor analyses. Using factor analyses and cut-off rules, the new instrument has 124 items grouped into 22 dimensions. The OHWQ demonstrated satisfactory reliability and validity, as well as reasonable fit indices. The internal consistency of the scales was also good (Cronbach's α = 0.68-0.96, median = 0.85). CONCLUSION: The OHWQ demonstrated good psychometric properties. It could be useful for both research purposes and for workplaces interested in developing concrete action plans aimed at improving the balance between psychosocial work stressors and resources.

A longitudinal molecular study of the ecology of malaria infections in free-ranging mandrills.

Unravelling the determinants of host variation in susceptibility and exposure to parasite infections, infection dynamics and the consequences of parasitism on host health is of paramount interest to understand the evolution of complex host-parasite interactions. In this study, we evaluated the determinants, temporal changes and physiological correlates of Plasmodium infections in a large natural population of mandrills (Mandrillus sphinx). Over six consecutive years, we obtained detailed parasitological and physiological data from 100 male and female mandrills of all ages. The probability of infection by Plasmodium gonderi and P. mandrilli was elevated (ca. 40%) but most infections were chronical and dynamic, with several cases of parasite switching and clearance. Positive co-infections also occurred between both parasites. Individual age and sex influenced the probability of infections with some differences between parasites: while P. mandrilli appeared to infect its hosts rather randomly, P. gonderi particularly infected middle-aged mandrills. Males were also more susceptible to P. gonderi than females and were more likely to be infected by this parasite at the beginning of an infection by the simian immunodeficiency virus. P. gonderi, and to a lesser extent P. mandrilli, influenced mandrills' physiology: skin temperatures and neutrophil/lymphocyte ratio were both impacted, generally depending on individual age and sex. These results highlight the ecological complexity of Plasmodium infections in nonhuman primates and the efforts that need to be done to decipher the epidemiology of such parasites.

Ballasting by cryogenic gypsum enhances carbon export in a Phaeocystis under-ice bloom.

Mineral ballasting enhances carbon export from the surface to the deep ocean; however, little is known about the role of this process in the ice-covered Arctic Ocean. Here, we propose gypsum ballasting as a new mechanism that likely facilitated enhanced vertical carbon export from an under-ice phytoplankton bloom dominated by the haptophyte Phaeocystis. In the spring 2015 abundant gypsum crystals embedded in Phaeocystis aggregates were collected throughout the water column and on the sea floor at a depth below 2 km. Model predictions supported by isotopic signatures indicate that 2.7 g m-2 gypsum crystals were formed in sea ice at temperatures below -6.5 °C and released into the water column during sea ice melting. Our finding indicates that sea ice derived (cryogenic) gypsum is stable enough to survive export to the deep ocean and serves as an effective ballast mineral. Our findings also suggest a potentially important and previously unknown role of Phaeocystis in deep carbon export due to cryogenic gypsum ballasting. The rapidly changing Arctic sea ice regime might favour this gypsum gravity chute with potential consequences for carbon export and food partitioning between pelagic and benthic ecosystems.

Using a sequential explanatory mixed method to evaluate the therapeutic window of opportunity for initiating osteoporosis treatment following fragility fractures.

Interventions targeting patients with recent fragility fracture and their physician were most successful at initiating osteoporosis treatment during the first 12 months. This window of opportunity had already closed after 1 year. The reasons for declining or accepting the intensive intervention were explored in patients still untreated at 12 months. INTRODUCTION: A fragility fracture (FF) event identifies patients most likely to benefit from osteoporosis treatment. Nonetheless, most FF patients go untreated. Our objective was to determine how long an incident FF remains a strong incentive to initiate osteoporosis treatment. METHODS: A total of 1086 men and women over age 50 with a recent FF event were assigned to either standard care (SC), to minimal (MIN), or intensive (INT) interventions targeting patients and their family physician to initiate osteoporosis treatment. Inpatients with FF (mainly hip) evaluated by rheumatologists were also included in a specialized group (SPE; n = 324). At 1 year, untreated patients in both the SC and the MIN groups were offered an INT intervention. The cohort was followed through 48 months. A qualitative analysis of patient-centered decision-making associated with initiation of treatment was conducted. RESULTS: In MIN and INT groups, osteoporosis treatment was initiated in 41.0 and 54.3% of untreated patients by 12 months, respectively, compared to 68.4% in SPE and 18.9% in SC groups; initiation rates drastically dropped thereafter. Over 4863 patient-years of follow-up, the rates of new FF were 3.4 per 100 patient-years, without significant differences between patients with initial major or minor FF, nor between control or intervention groups. Failure by patients and physicians to recognize FF as a sign of underlying bone disease contributed the most to lack of treatment. CONCLUSION: While incident FFs are an ideal opportunity for starting osteoporosis treatment, 1 year later, the therapeutic window of opportunity has already closed.

Risk of Subsequent Fragility Fractures Observed After Low-Trauma Ankle Fractures.

While fragility fractures (FFs) are one of the strongest predictors of subsequent osteoporotic fractures, it remains unclear whether low-trauma ankle fractures have this ability. The aim of the study was to identify the characteristics of patients with low-trauma ankle FFs who develop subsequent FFs. The OPTIMUS initiative is a strategy to improve osteoporosis treatment post-FF in orthopedic clinics. FRAX scores without BMD (FRAX-BMI) were calculated at time of inclusion. Recurrent FFs were recorded over a 48-month follow-up. All FFs were X-ray-confirmed. A total of 265 patients with initial ankle FF were included (190 women; mean age 62.8 ± 9.6 years), of whom 15 developed new FFs. Patients with ankle FFs had longer time until recurrence and lower 2-year incidence of recurrent FFs (3.2%) compared with those having wrist FFs (9.0%) or other initial FFs (9.6%), and 4-year incidence rates of 6.2, 13.4, and 15.3%, respectively (log-rank test, p = 0.001). With an ankle FF at inclusion, recurrent FFs were more frequent in patients with previous FF (6.2 per 100 patient-years; p < 0.01) or high-risk FRAX-BMI scores pre- or post-FF (2.4 or 2.0 per 100 patient-years, respectively; ns), compared to patients without any of these conditions (0.7 per 100 patient-years). Ankle FFs represent a clinical opportunity for identifying at-risk patients who should be targeted for treatment (previous FFs and/or high-risk FRAX). Because of mechanical factors and other contributors involved, ankle FFs themselves do not predict subsequent FFs overall, and their inclusion in FRAX-BMI risk calculation may thus not be warranted.

Altered brain processing of decision-making in healthy first-degree biological relatives of suicide completers.

Suicidal behavior is heritable, with the transmission of risk being related to the transmission of vulnerability traits. Previous studies suggest that risky decision-making may be an endophenotype of suicide. Here, we aimed at investigating brain processing of decision-making in relatives of suicide completers in order to shed light on heritable mechanisms of suicidal vulnerability. Seventeen healthy first-degree biological relatives of suicide completers with no personal history of suicidal behavior, 16 relatives of depressed patients without any personal or family history of suicidal behavior, and 19 healthy controls were recruited. Functional 3 T magnetic resonance imaging scans were acquired while participants underwent the Iowa Gambling Task, an economic decision-making test. Whole-brain analyses contrasting activations during risky vs safe choices were conducted with AFNI and FSL. Individuals with a family history of suicide in comparison to control groups showed altered contrasts in left medial orbitofrontal cortex, and right dorsomedial prefrontal cortex. This pattern was different from the neural basis of familial depression. Moreover, controls in comparison to relatives showed increased contrast in several regions including the post-central gyrus, posterior cingulate and parietal cortices, and cerebellum (culmen) in familial suicide; and inferior parietal, temporal, occipital, anteromedial and dorsolateral prefrontal cortices, and cerebellum (vermis) in familial depression. These findings most likely represent a complex combination of vulnerability and protective mechanisms in relatives. They also support a significant role for deficient risk processing, and ventral and dorsal prefrontal cortex functioning in the suicidal diathesis.

Glycaemic control and self-management behaviours in Type 2 diabetes: results from a 1-year longitudinal cohort study.

AIM: To better understand the associations between changes in self-management behaviours and glycaemic control. METHODS: We conducted a prospective observational study of 295 adult patients with Type 2 diabetes evaluated at baseline, 6 and 12 months. Four self-management behaviours were evaluated using the Summary of Diabetes Self-Care Activities instrument, which assesses healthy diet, physical activity, medication taking and self-monitoring of blood glucose. Using hierarchical linear regression models, we tested whether changes in self-management behaviours were associated with short-term (6-month) or long-term (12-month) changes in glycaemic control, after controlling for demographic and clinical characteristics. RESULTS: Improved diet was associated with a decrease in HbA1c level, both at 6 and 12 months. Improved medication taking was associated with short-term improvement in glycaemic control, while increased self-monitoring of blood glucose frequency was associated with a 12-month improvement in HbA1c . Completely stopping exercise after being physically active at baseline was associated with a rise in HbA1c level at 6-month follow-up. Interaction analysis indicated that a healthy diet benefitted all participant subgroups, but that medication taking was associated with glycaemic control only for participants living in poverty and more strongly for those with lower educational levels. Finally, a higher self-monitoring of blood glucose frequency was associated with better glycaemic control only in insulin-treated participants. CONCLUSIONS: Even after adjusting for potential confounders (including baseline HbA1c ), increased frequency of healthy diet, medication taking and self-monitoring of blood glucose were associated with improved HbA1c levels. These self-management behaviours should be regularly monitored to identify patients at risk of deterioration in glycaemic control. Barriers to optimum self-management should be removed, particularly among socio-economically disadvantaged populations.

[Elder abuse: practice issues for physicians]. / La maltraitance envers les personnes âgées: quelques éléments pour la pratique médicale.

Elder abuse is frequent (from 4 to 6% of adults aged 65 + according to WHO). It can take various forms: psychological, financial, violation of rights, neglect and physical. Due to demographic changes, it is expected that the number of cases will increase over coming years. Scientific data show the importance of a systemic analysis of elder abuse situations in order to avoid the simplistic thinking of the "horrible abuser" and the "poor victim". A multidisciplinary team, including a physician (a general practitioner, or a specialist), is necessary. Physicians can play a role in the prevention, detection and follow up of such cases. In order to detect elder abuse, active and attentive listening is mandatory. When a possibility exists that the older adult is abused, the suspicion should be documented (per example, by using the EASI tool), in order to implement an adequate follow-up. In the French part of Belgium, specialised services can be involved: Respect Seniors (www.respectseniors.be) in Wallonia and the SEPAM d'Infor-Homes in Brussels.

Real-time feedback on knee abduction moment does not improve frontal-plane knee mechanics during jump landings.

Excessive knee abduction loading is a contributing factor to anterior cruciate ligament (ACL) injury risk. The purpose of this study was to determine whether a double-leg landing training program with real-time visual feedback improves frontal-plane mechanics during double- and single-leg landings. Knee abduction angles and moments and vertical ground reaction forces (GRF) of 21 recreationally active women were quantified for double- and single-leg landings before and after the training program. This program consisted of two sessions of double-leg jump landings with real-time visual feedback on knee abduction moments for the experimental group and without real-time feedback for the control group. No significant differences were found between training groups. In comparison with pre-training data, peak knee abduction moments decreased 12% post-training for both double- and single-leg landings; whereas peak vertical GRF decreased 8% post-training for double-leg landings only, irrespective of training group. Real-time feedback on knee abduction moments, therefore, did not significantly improve frontal-plane knee mechanics during landings. The effect of the training program on knee abduction moments, however, transferred from the double-leg landings (simple task) to single-leg landings (more complex task). Consequently, ACL injury prevention efforts may not need to focus on complex tasks during which injury occurs.

Gene expression biomarkers of response to citalopram treatment in major depressive disorder.

There is significant variability in antidepressant treatment outcome, with ∼30-40% of patients with major depressive disorder (MDD) not presenting with adequate response even following several trials. To identify potential biomarkers of response, we investigated peripheral gene expression patterns of response to antidepressant treatment in MDD. We did this using Affymetrix HG-U133 Plus2 microarrays in blood samples, from untreated individuals with MDD (N=63) ascertained at a community outpatient clinic, pre and post 8-week treatment with citalopram, and used a regression model to assess the impact of gene expression differences on antidepressant response. We carried out technical validation of significant probesets by quantitative reverse transcriptase PCR and conducted central nervous system follow-up of the most significant result in post-mortem brain samples from 15 subjects who died during a current MDD episode and 11 sudden-death controls. A total of 32 probesets were differentially expressed according to response to citalopram treatment following false discovery rate correction. Interferon regulatory factor 7 (IRF7) was the most significant differentially expressed gene and its expression was upregulated by citalopram treatment in individuals who responded to treatment. We found these results to be concordant with our observation of decreased expression of IRF7 in the prefrontal cortex of MDDs with negative toxicological evidence for antidepressant treatment at the time of death. These findings point to IRF7 as a gene of interest in studies investigating genomic factors associated with antidepressant response.

Ecophysiological response of Adelie penguins facing an experimental increase in breeding constraints.

Foraging strategies play a key role in breeding effort. Little is known, however, about their connection with hormonal and nutritional states, especially when breeding constraints vary. Here, we experimentally increased foraging costs and thus breeding constraints by handicapping Adélie penguins (Pygoscelis adeliae) with dummy devices representing 3-4% of the penguins' cross-sectional area. We examined food-related stress (via plasma corticosterone concentration) and nutritional state (via metabolite levels). Concurrently, we investigated the use of ecological niches via the isotopic signature of red blood cells indicating the trophic position (delta(15)N) and the spatial distribution (delta(13)C) of penguins. Handicapped birds performed approximately 70% longer foraging trips and lost approximately 60% more body mass than controls and their partners. However, corticosterone levels and the nutritional state were unchanged. The isotopic signature revealed that males and females differed in their foraging behaviour: upper trophic levels contributed more in the males' diet, who foraged in more pelagic areas. Handicapped and partner birds adopted the same strategy at sea: a shift towards higher delta(13)C values suggested that they foraged in more coastal areas than controls. This change in foraging decisions may optimize feeding time by decreasing travelling time. This may partly compensate for the presumed lower foraging efficiency of handicapped birds and for the energetic debt of their partners who had to fast approximately 70% longer on the nest. We propose that this flexible use of ecological niches may allow birds facing increased breeding constraints to avoid chronic stress and to minimize the impact on their body condition.

Analysis of bovine sexed sperm for IVF from sorting to the embryo.

The objective of this study was to characterize bovine semen parameters and determine the best IVF conditions to produce a maximal percentage of blastocysts. Four types of semen were analyzed with CASA and flow cytometry: fresh and frozen non-sexed semen; fresh and frozen sexed semen. Semen was obtained from four Holstein bulls and two ejaculates from each bull were analyzed. Oocytes from slaughterhouse ovaries were matured and fertilized in vitro with all types of semen (for sexed semen, 2, 5 or 10microg/mL heparin was added to the IVF media while for non-sexed semen, 10microg/mL was added in the IVF medium). Presumptive zygotes were co-cultured with Buffalo rat liver cells in Menezo's B2 medium, and cleavage rates at Day 2, and blastocyst rates at Day 7 of culture, were recorded. Sexed semen resulted in fewer blastocysts than non-sexed semen (P<0.05), and certain bulls performed better in IVF. Freezing, and not sexing, had a more significant negative effect on semen quality. Compromised semen quality due to sexing and/or freezing can explain the reduced in vitro blastocyst rates when using frozen-thawed sexed semen. Sexed semen that appeared more capacitated seemed to require less heparin in IVF than sexed semen that appeared less capacitated to produce a maximal percentage of blastocyst. Flow cytometry sorting eliminates spermatozoa that possess compromised DNA, and therefore the reduced fertility seen in vitro is not due to an increased percentage of spermatozoa with compromised DNA. This study describes tools that can monitor semen parameters to optimize IVF conditions and thus obtain maximal blastocyst rates.

The care gap in diagnosis and treatment of women with a fragility fracture.

UNLABELLED: In women aged 50 years or more who experienced a fracture, 81% suffered a fragility fracture. Six to eight months after fragility fracture, 79% had either not been investigated for osteoporosis or prescribed anti-fracture therapy. Despite fragility fractures being common in this population osteoporosis is under-diagnosed and under-treated. INTRODUCTION: The objective of this study was to evaluate the diagnostic and treatment rates for osteoporosis six months following fragility fracture. METHODS: This prospective cohort study was set in the general community from the Province of Quebec, Canada. Women at least 50 years of age who suffered a fracture were recruited during their initial visit to the hospital and had their fracture type classified as either fragility or traumatic. Six-to-eight months after fragility fracture, women were again contacted to evaluate the diagnostic and treatment rates of osteoporosis. RESULTS: Of the 2,075 women recruited over a 25 month period 1,688 (81%) sustained a fragility fracture and 387 (19%) sustained a traumatic fracture. Nine hundred and three participants with a fragility fracture were again contacted six-to-eight months after fracture. For the 739 women not on treatment on the recruitment day, only 15.4% initiated pharmacological therapy in the six-to-eight-month period following fracture and 79.0% had either not been investigated for osteoporosis or prescribed anti-fracture treatment. CONCLUSIONS: The proportion of fragility fractures to total fractures is higher than previously reported. Despite the availability of diagnostic modalities, effective treatments, and adequate health care assessments, there is a substantial care gap in the management of osteoporosis.

Stenosis at the area of transposition - an under-recognized complication of transposed brachiobasilic fistulas.

BACKGROUND: With an increased focus on native AV fistula creation in hemodialysis patients, a transposed brachiobasilic fistula (tBBF) is becoming an increasingly utilized option. This study describes the outcomes of tBBFs in a chronic hemodialysis population. In particular, we focus on the incidence and location of stenosis, and review the impact of angioplasty on these lesions. METHODS: A retrospective cohort study using all patients with a tBBF created between January 2001 and December 2004. RESULTS: Of the 543 fistulas created during the study period, 93 were tBBFs. The mean age of patients was 65 years, 56% were male and 55% were diabetic. Stenosis occurred in 54% (46/85) of fistulas; the location of stenosis in the majority (74%) was at or near the area of basilic vein transposition and 50% of fistulas with stenosis in this location required three or more angioplasties. Primary (unassisted) patency was 42% at one year in this cohort. Secondary patency was 68% at 1 year and 58% and 53% at 2 and 3 years respectively. CONCLUSION: In a cohort of hemodialysis patients who received a tBBF, we describe a reasonable primary and secondary patency rate and a high rate of stenosis at the point of transposition of the basilic vein. Such stenosis usually requires multiple percutaneous or surgical interventions to ensure or reestablish conduit patency. Further study is required regarding the optimal surgical technique, monitoring, and treatment of stenosis of this fistula type including the utility of repeat angioplasty.

Effect of 1,1-dimethylphenyl 1,4-piperazinium on mouse tracheal smooth muscle responsiveness.

Bronchial hyperresponsiveness is one of the main features of asthma. A nicotinic receptor agonist, 1,1-dimethylphenyl 1,4-piperazinium (DMPP), has been shown to have an inhibitory effect on airway response to methacholine in an in vivo model of asthma. The aims of this study were to 1) verify whether nicotinic acetylcholine receptors (nAChR) were present on mouse tracheal smooth muscle, 2) verify whether bronchoprotection observed in mice was due to a direct effect on airway smooth muscle, and 3) compare the effects of nicotinic agonists to that of salbutamol. Alpha3-, alpha4-, and alpha7-nAChR subunits were detected by immunofluorescence on tracheal tissues from normal BALB/c mice. The effect of DMPP on tracheal responsiveness was verified by an isometric method. Tracheas were isolated from normal mice, placed in organ baths, and contracted with a single dose of methacholine. Cumulative doses of DMPP or salbutamol were added to the baths. Results show that mouse tracheal smooth muscle is positive for alpha4- and alpha7-nAChR subunits and that the epithelium is positive for alpha3-, alpha4-, and alpha7-subunits. DMPP induced a greater dose-dependent relaxation of tracheal smooth muscles precontracted with methacholine than with salbutamol. These results suggest that the smooth muscle-relaxing effect of DMPP could have some interest in the treatment of obstructive pulmonary diseases.

Physicians' attitudes to the pharmacological treatment of patients with stable angina pectoris.

BACKGROUND: Little is known about how physicians' knowledge of and attitudes to practice guidelines for stable angina may influence their implementation. AIM: To explore the association between physicians' demographics, their knowledge, and opinions about stable angina and their self-reported adherence to guideline recommendations. DESIGN: Questionnaire-based survey. METHODS: We surveyed 1228 Quebec physicians using a questionnaire based on the 'awareness-to-adherence' conceptual framework to measure their adherence with recommendations for the pharmacological treatment of stable angina. Independent predictors of adherence with the targeted recommendations were determined by stepwise linear regression analysis. RESULTS: We received 877 (71.4%) responses from the 1228 eligible physicians. More than 90% of respondents were aware of and agreed with the targeted recommendations. However, the adoption rate varied, even among physicians who generally agreed with the guidelines. Factor analysis indicated that most physicians agreed with recommendations concerning ASA. More negative attitudes were expressed toward beta-blockers and hypolipaemic drugs. Respondents trusted the recommendations of a variety of scientific and professional organizations. Awareness, agreement, and adoption were the strongest predictors of adherence for the three recommendations. Physician demographics and practice characteristics did not predict adherence. DISCUSSION: Physicians were aware of and agreed with the recommendations, so additional large-scale dissemination of the guidelines would be unlikely to improve prescription patterns. However, negative attitudes about beta-blockers and hypolipaemic therapy affected adherence to recommendations for these drugs. Continuing medical education interventions involving local opinion leaders might address some of the obstacles identified.

Drug treatment of stable angina pectoris and mass dissemination of therapeutic guidelines: a randomized controlled trial.

BACKGROUND: Public agencies responsible for implementing health care policies often adapt and disseminate clinical practice guidelines, but the effectiveness of mass dissemination of guidelines is unknown. AIM: To study the effects of guideline dissemination on physicians' prescribing practices for the treatment of stable angina pectoris. DESIGN: Randomized controlled trial. METHODS: A sample of 3293 Quebec physicians were randomly assigned to receive a one-page summary of clinical practice guidelines on the treatment of stable angina (in February 1999), to receive the summary and a reminder (in February and March 1999, respectively), or to receive no intervention (controls). The prescribing profiles of participants, as well as sociodemographic characteristics of the physicians and their patients, were examined for June-December 1999. RESULTS: The intervention had no effect on prescription rates of beta-blockers, antiplatelet agents, or hypolipaemic drugs. Compared to 1997 data for the same physicians, there was an overall 10% increase in appropriate prescription rates, irrespective of the intervention. DISCUSSION: In-house production and dissemination of clinical practice guidelines may not improve physicians' practice patterns if there is pre-existing substantial scientific consensus on the issue.

Determination of hepatitis B virus subtypes by an enzyme immunoassay method using monoclonal antibodies to type-specific epitopes of HBsAg.

We described a Hepatitis B surface antigen (HBsAg) subtyping method based on a commercial enzyme immunoassay (EIA) for detection of HBsAg in which the procedure was modified to include the use of monoclonal antibodies with restricted anti-HBs specificities. This method, which was able to classify HBsAg as: ayw1, ayw2, ayw3, ayw3* (intermediate between ayw3 and ayw4), ayw4, ayr, adw2, adw4 and adr, was compared to counter electrophoresis procedure (CEP) by testing HBsAg positive sera from blood donors included in a prospective national epidemiological survey. Among the 256 HBsAg positive samples tested with both techniques, 111 (43.3%) could not be subtyped with CEP vs 10 (3.9%) with our modified EIA. This difference was related to the serum HBsAg concentration which must be greater than 3000 ng/mL and 100 ng/mL for CEP and EIA, respectively. The results obtained from 145 sera with both methods were concordant. Seventeen out of 18 samples partially classified as ay with CEP were completely determined with EIA. This reliable procedure, derived from commercially available reagents, can be easily used in several applications such as large epidemiologic studies and as a substitute for nucleotide sequencing genotyping which is not adapted for large-scale screening and not applicable on samples from nonviremic hepatitis B virus (HBV) carriers.

Fast and robust optic disc detection using pyramidal decomposition and Hausdorff-based template matching.

We report about the design and test of an image processing algorithm for the localization of the optic disk (OD) in low-resolution (about 20 micro/pixel) color fundus images. The design relies on the combination of two procedures: 1) a Hausdorff-based template matching technique on edge map, guided by 2) a pyramidal decomposition for large scale object tracking. The two approaches are tested against a database of 40 images of various visual quality and retinal pigmentation, as well as of normal and small pupils. An average error of 7% on OD center positioning is reached with no false detection. In addition, a confidence level is associated to the final detection that indicates the "level of difficulty" the detector has to identify the OD position and shape.