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Biomedical subjects

A Verrier

Publications and source records attributed to A Verrier.

17 recordsLinked to original sources
PubMed2005

Characterization of exposure to extremely low frequency magnetic fields using multidimensional analysis techniques.

Our lack of knowledge about the biological mechanisms of 50 Hz magnetic fields makes it hard to improve exposure assessment. To provide better information about these exposure measures, we use multidimensional analysis techniques to examine the relations between different exposure metrics for a group of subjects. We used a combination of a two stage Principal Component Analysis (PCA) followed by an ascending hierarchical classification (AHC) to identify a set of measures that would capture the characteristics of the total exposure. This analysis gives an indication of the aspects of the exposure that are important to capture to get a complete picture of the magnetic field environment. We calculated 44 metrics of exposure measures from 16 exposed EDF employees and 15 control subjects, containing approximately 20,000 recordings of magnetic field measurements, taken every 30 s for 7 days with an EMDEX II dosimeter. These metrics included parameters used routinely or occasionally and some that were new. To eliminate those that expressed the least variability and that were most highly correlated to one another, we began with an initial Principal Component Analysis (PCA). A second PCA of the remaining 12 metrics enabled us to identify from the foreground 82.7% of the variance: the first component (62.0%) was characterized by central tendency metrics, and the second (20.7%) by dispersion characteristics. We were able to use AHC to divide the entire sample (of individuals) into four groups according to the axes that emerged from the PCA. Finally, discriminant analysis tested the discriminant power of the variables in the exposed/control classification as well as those from the AHC classification. The first showed that two subjects had been incorrectly classified, while no classification error was observed in the second. This exploratory study underscores the need to improve exposure measures by using at least two dimensions: intensity and dispersion. It also indicates the usefulness of constructing a typology of magnetic field exposures.

Algorithms↗
PubMed2003

Legislative recognition in France of psychological harassment at work.

The recent French Law on Social Modernisation of 17 January 2002 introduced into the French Labour Code and into the French Criminal Code, the concept of "moral" harassment. The definition of psychological harassment under this law adopts quite a broad conception of the notion of psychological harassment. The legislator has established a means for "friendly" settlement of disputes: mediation. When it has not been possible to settle the dispute internally, the Courts have a number of sanctions available to them. The French Labour Code provides that any termination of the contract of employment resulting from a situation of psychological harassment is automatically null and void. Such nullification should therefore be applicable whatever the nature of the termination: dismissal, resignation or negotiated departure and it punishes psychological harassment at work by imprisonment for one year and a fine of 3,750 Euros. The French Criminal Code prescribes penalties of one year and 15,000 Euros.

Civil Rights↗
PubMed2001

Factorial structure of the Sensation-Seeking Scale-Form V: confirmatory factorial analyses in nonclinical and clinical samples.

OBJECTIVE: The factor structure of the Sensation-Seeking Scale (SSS)-Form V was studied in 2 large French samples, using confirmatory factorial analyses (CFA) to test the 4-dimensional model of sensation seeking postulated by Zuckerman. METHOD: The study included 769 healthy subjects and 659 patients who met the DSM-IV criteria for substance use disorders or eating disorders and completed the SSS. The correlation matrices for each of the samples were analyzed using CFA. RESULTS: In each sample, we found the 4-factor model to be replicable. CONCLUSION: The multidimensionality of sensation seeking is supported by the results, and the 4-dimensional model of sensation seeking identified by Zuckerman can be explored in French-speaking people.

Adolescent↗
PubMed1998

Depression and dependency: distinct or overlapping constructs?

BACKGROUND: Previous research has found a significant positive relationship between dependency and level of depression. The aim of the present study, using factor analysis method, is to test the hypothesis that dependency and depression constitute distinct dimensions. METHODS: In a sample of 202 university students, a correlation matrix comprising items from both the Interpersonal Dependency Inventory and the abridged form of the Beck Depression Inventory was analysed using a principal components analysis followed by an orthogonal varimax rotation. RESULTS: Evidence for a four-factor solution was found with almost no overlap of the significant factor loadings for the items from each scale, and with the factors corresponding closely with their respective construct. CONCLUSION: The findings support the view that depression and dependency constitute different constructs. LIMITATION: The results must be confirmed on clinical and heterogeneous nonclinical samples. CLINICAL RELEVANCE: The independency between depression and dependency could lead to different therapeutic strategies notably in 'socially dependent' type of depression.

Adult↗
PubMed1997

Prevalence and time trends of disabilities in school-age children.

BACKGROUND: Although the evolution of the prevalence of cerebral palsy is now well documented, much less is known about the evolution of the prevalence of other disabilities such as mental retardation, sensorial defects, autism and psychosis. The aim of this paper is to determine those trends. METHODS: A population-based survey was carried out in 1992-1993 in three French 'départments'. All disabled children born between 1976 and 1985 and receiving a special education and/or financial assistance were systematically registered. RESULTS: The comparison of three cohorts of children born in 1976-1978, 1979-1981 and 1982-1984 using the test for trend in proportion showed a significant decrease (P = 0.03) in the prevalence of severe mental retardation, after exclusion of Down syndrome. This decrease was significant for severe mental retardation associated with psychosis. The time trend prevalence for cerebral palsy increased (P = 0.03) but was irregular. The time trend prevalence of other disabilities (other motor defects, severe sensorial disabilities, autism and psychosis) did not change significantly. A detailed analysis of severe mental retardation and cerebral palsy was performed by geographical area, age at first registration and type of disability. CONCLUSION: The increase in prevalence of cerebral palsy is possibly due to earlier registration of disabled children. The decrease in prevalence of severe mental retardation does not seem to be due to recruitment bias, but there is a possibility of classification bias.

Adolescent↗
PubMed1996

[Motor deficiencies in children: for a nosologic clarification in epidemiological studies].

In order to clarify the epidemiological research on childhood motor deficiency in France there is a need to better differenciate the two terms used to define this pathology: the French term "infirmité motrice cérébrale" (IMC) and the English term "cerebral palsy" (CP). The distinction between IMC and CP is highlighted on the basis of clinical examples. IMC recovers motor deficiencies which are quite similar, however, it can be very difficult to control the variations in its use. CP has the advantage of a greater exhaustivity as well as a greater reproductibility for epidemiological records. Recently a study was conducted for measuring the prevalence of childhood deficiencies in France, and the results were expressed either as IMC or as CP. When using the CP definition the prevalence rate in France was found to be close to that of foreign studies (1.9 per thousand). In studies with etiological purposes involving several countries, a preliminary agreement on the definition of the clinical groups is absolutely necessary.

Adolescent↗
PubMed1996

Factor analysis of the French version of the 20-Item Toronto Alexithymia Scale (TAS-20).

A French version of the Toronto Alexithymia Scale-20 Items (TAS-20) was factor-analyzed on a sample of 263 university students and its factor solution analyzed along with the studies using the Canadian version. Our results show a two-factor solution where the items rating the difficulty to identify feelings and the items rating the difficulty to describe feelings constitute a sole factor contrary to the Canadian version. These data are reviewed in the context of previous research and offer two subscales for future investigations utilizing the TAS-20.

Adolescent↗
PubMed1995

[Prevalence of alexithymia in a general population. Study in 183 "normal" subjects and in 263 students].

The prevalence of alexithymia has been studied in two groups of healthy subjects, 183 normals and 263 university students. In the normal group the alexithymia was rated using the Toronto Alexithymia Scale (TAS) and in the student group the alexithymia was rated using the revised version of the TAS (Twenty-items TAS or TAS-20). Using our cutoff scores (> or = 73 for the TAS, > or = 56 for the TAS-20), the prevalence in the normal group and the student group were respectively 23% and 17.1%.

Adolescent↗
PubMedDate not supplied

[High-risk suicide attempts: intent and severity].

This study of 764 suicide attempts has for objective to define the factors which distinguish the "high-risk" group from other groups. The "high-risk" group is composed of people having scored more than 10 on Pierce's Intent Scale and more than 45 on the Weissman scale. Results show that the intensity and form of depressive symptomatology and some representations of death and age distinguish this group (n = 80) and that previous suicidal attempts, alcohol intake, chronic alcoholism and recent events have no statistical value.

Adolescent↗
PubMedDate not supplied

[Validation of the French version of the revised Personal Style Inventory (revised Personal Style Inventory, PSI-II, Robins et al., 1994)].

The aim of the present study is to determine the validity and reliability of the French version of the PSI-II. The PSI-II is a self-rating scale divided into two subscales containing each 24 items and rating sociotropy and autonomy. 202 university students (170 females, 32 males) with a mean age of 21.54 years (sd = 4.16) were included. They filled out the PSI-II and the Interpersonal Dependency Inventory (IDI). The construct validity was explored using an exploratory principal components analysis followed by an orthogonal varimax rotation. The results had shown a three-factor solution with a "sociotropy" factor and two "autonomy" factors. The Cronbach alpha coefficients were respectively 0.83 and 0.72 for the sociotropy and autonomy subscales. The Pearson correlations between the PSI-II and IDI subscales showed significant correlation first between the sociotropy subscale and the two subscales of the IDI rating dependency, the values were respectively 0.67 (p < 0.001) and 0.44 (p < 0.001), and secondly between the autonomy subscales of the PSI-II and IDI, the value was 0.39 (p < 0.001). The sociotropy subscale items correlated significantly with the total score of the subscale with a mean of 0.46. 23 items of the autonomy subscale correlated with the total score with a mean of 0.36. The sociotropy and autonomy scores were respectively 93.98 (sd = 14.22) and 84.55 (sd = 11.69). The French version of the PSI-II had satisfactory metrological parameters and allows to study sociotropy and autonomy in French population.

Adolescent↗