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C Fortin

Publications and source records attributed to C Fortin.

At least 19 recordsLinked to original sources
PubMed1999

Order information in short-term memory and time estimation.

In previous experiments, the amount of interference between time production and visual or memory search tasks was shown not to be related to the level of difficulty of the search task per se, but instead to the amount of processing in short-term memory required in the search task. The first experiment of the present study verified whether the amount of interference between time production and a short-term memory task may be related to the level of difficulty of the short-term memory task. Two versions of a memory task, with and without processing of order information, were combined with a temporal interval production task in a concurrent processing condition. As is shown in a control reaction time task, processing order information increased the level of difficulty of the memory search task. In the concurrent processing condition, the interference between short-term memory processing and time production was stronger when the level of difficulty of the short-term memory search task was increased by requiring that order information be processed. The results of Experiment 2 showed that the amount of interference between a similar short-term memory task and time production seems not to be related to the amount of order information that must be maintained during the time production task. This dissociation between the effects of processing and the maintenance of order information is compatible with a similar dissociation, observed in previous experiments, between the effects of processing and those of maintaining item information in short-term memory on concurrent time production.

Adult↗
PubMed1998

Interference from short-term memory processing on encoding and reproducing brief durations.

A temporal reproduction task is composed of two temporal estimation phases: encoding of the interval to be reproduced, followed by its reproduction. The effect of short-term memory processing on each of these phases was tested in two experiments. In Exp. 1, a memory set was presented, followed by two successive tones bounding the target interval to be reproduced. During the reproduction of the target interval, a probe was presented, and the subject ended the reproduction by pressing one of two keys, depending on the presence or absence of the probe in the memory set. In Exp. 2, probe recognition was required during the encoding of the interval to be reproduced. Whereas in Exp. 1 reproductions lengthened as a function of memory-set size, in Exp. 2 temporal reproductions decreased with set size. These results support attentional models of time estimation and suggest that short-term memory processing interrupts concurrent accumulation of temporal information.

Adult↗
PubMed1998

Understanding physicians' intention to use a simple infection control measure: wearing gloves.

OBJECTIVE: The aim of this study was to identify the factors that explain the intention of physicians to wear gloves when contact with blood or body fluids was possible. METHODS: A survey was given to a representative sample of physicians (general practitioners, medical specialist, and surgeons of the Canadian province of Québec). A total of 720 physicians completed the self-administered questionnaire. The respondents' intention to wear gloves, psychosocial variables (attitude, perceived social norm, perceived behavioral control, perceived risk of infection, and habit of wearing gloves), and sociodemographic variables were assessed. RESULTS: A substantial proportion of physicians (80%) had strong intentions to wear gloves when contact with blood and body fluids was possible. Logistic regression indicated that the 3 most important factors explaining intention were perceived behavioral norm, attitudes, and perceived behavioral control. Perceived risk of infections, habit of wearing gloves, and being in a younger age category were additional factors related to intention. CONCLUSIONS: Interventions should reinforce the perception that the use of gloves is the norm among medical professionals. These programs also should emphasize the advantages of wearing gloves, counteract the perceived disadvantages of wearing them, and enhance the ability of physicians to circumvent the difficulties of wearing gloves when required.

Adult↗
PubMed1996

Gynecare UBT System Under Local Anesthesia

Numerous investigators reported that the Gynecare uterine balloon therapy (UBT) system appears to be safe and effective treatment for women with excessive uterine bleeding due to benign causes. Since the catheter has a diameter of less than 5 mm, the instrument can be inserted with minimal or no cervical dilatation under local anesthesia. We treated 39 women with the UBT, with a success rate of 88% in women followed for as long as 1 year. The first few cases were performed under general anesthesia, and the next series was done successfully with intravenous sedation. Ten procedures were performed using local anesthetic only. After oral premedication with a nonsteroidal antiinflammatory drug and local injection of 1% lidocaine with epinephrine 1:100,000, the technique was well tolerated by all 10 patients. No complications occurred during or after the procedure. Satisfaction of the women after 24 hours was 90%. In our experience, UBT was safe and effective, and appeared to be well tolerated when done under local anesthesia. It is well suited to be performed in an office setting, and should provide a significant cost saving for the treatment of menorrhagia compared with surgical alternatives.

Journal Article↗
PubMed1996

Uterine Balloon Therapy for the Treatment of Menorrhagia

From June 1994 to December 1995, 116 women (mean age 39 yrs, range 27-50 yrs) who met inclusion and exclusion criteria underwent endometrial ablation with a thermal balloon system. Forty-one (35%) were treated under general and 71 (61%) under neuroleptic anesthesia. Four (3%) treatments were performed under paracervical block only. A 16-cm long, 3-mm diameter catheter with a latex balloon at its tip housing a heating element was inserted into the uterus and filled with sterile 5% dextrose in water solution (mean 10.4 ml, range 2-55 ml). The catheter was connected to a control unit that maintained the temperature at 87 ± 5° C, monitored the pressure, and terminated the treatment after 8 minutes. The starting uterine pressure was 80 to 140 mm Hg in the first 13 women and greater than 140 mm Hg in the rest. Nineteen women were treated for 12 minutes and all others for 8 minutes. Complications were endometritis (3), hematometra (2), and cystitis (1). At 6-month follow-up, after 8 minutes of treatment, persistent menorrhagia was reported by 38% and 12% of patients at less than and greater than 140 mm Hg pressure, respectively. At greater than 140 mm Hg pressure, menorrhagia was reported by 13% of women after 8 and 12 minutes of treatment. In 38 women, amenorrhea or spotting occurred in 29%, hypomenorrhea in 45%, eumenorrhea in 21%, and menorrhagia in 5%. Uterine balloon therapy is a safe and effective treatment for menorrhagia at uterine pressures of 150 to 180 mm Hg and of 8 minutes' duration.

Journal Article↗
PubMed1996

Tapping sensitivity to processing in short-term memory.

This experiment examines the interference between tapping and searching in short-term memory (STM). In a concurrent processing condition, the subject first memorized a set of digits, and then executed a series of 17 taps separated by 2 s subjective time intervals. In each intertap interval, a probe was presented for comparison with the items in the memory set. The amount of processing in STM was varied from series to series by manipulating the number of items in the memory set. The results showed that mean duration and variability of intertap intervals increased proportionally with memory set size. This effect is explained by interference between processing in STM and the timing component of the tapping performance. Tapping sensitivity to memory load suggests that, under some conditions, variations in tapping performance are valid indicators of STM processing requirements of a concurrent primary task.

Adult↗
PubMed1996

HIV seropositive gay men: understanding adoption of safe sexual practices.

The aim of this study was to determine the best predictors of safe sex practices among HIV seropositive gay men. A group of 96 homosexual men living with HIV completed a questionnaire that investigated theoretical constructs of the Ajzen's (1988) theory of planned behavior with respect to condom use for anal intercourse and sexual practices without anal intercourse. Other variables such as Triandis's (1977) construct of personal normative belief, psychological distress, and alcohol and drug use before sexual encounters were also investigated. Results indicated that the best predictor of intention to use condoms was perceived behavioral control. Personal normative belief was another important predictor of this intention. Although the best predictor of intention to have only sex without anal intercourse was perceived subjective norm, this intention was also significantly explained by perceived behavioral control. Moreover, perceived behavioral control was a significant predictor of having only sex without anal intercourse. Public health interventions among HIV seropositive gay men should aim mainly at increasing perception of behavioral control.

Adult↗
PubMed1995

Temporal interval production and processing in working memory.

Short-term memory or working memory has been proposed as a cognitive structure contributing to time estimation. Thus, in a previous experiment, retrieving a stored item during a temporal-interval production lengthened the interval in proportion to the number of items in the memory set. In the present study, this issue was analyzed further by testing whether the proportional lengthening is induced by the load itself (i.e., the number of items) or by comparing the probe with memorized items. In a first experiment, a memory set was maintained during a temporal production, and the comparison of the probe with memorized items was postponed until the end of time production. Varying the number of items in the memory set had no effect on temporal intervals produced during its retention, suggesting that mental comparison was the source of the lengthening of time intervals. In succeeding experiments, tasks requiring processing in working memory but involving no memory load were combined with temporal production. In Experiment 2, increasing the number of syllables in a rhyme-judgment task proportionally lengthened temporal intervals that were produced simultaneously. In Experiment 3, increasing the amount of mental rotation in a task involving visuospatial processing also lengthened simultaneous temporal production. This interference between processing in working memory and time estimation suggests that working memory, defined as a work space for active processing of current information, contributes to time estimation.

Adult↗
PubMed1993

Frequency of sexually transmitted diseases among university students.

OBJECTIVE: To estimate the incidence rate of sexually transmitted diseases (STDs) among university students and evaluate the associated sociodemographic factors. DESIGN: Mail survey in April 1990. Included in the questionnaire were questions about the subjects' STD experience since their admission to the university and the type and date of the infection. SUBJECTS: Of the 19,682 undergraduate students 2920 subjects, in 10 groups of 292, were randomly selected. A total of 1731 (59.4%) completed the questionnaire. MAIN OUTCOME MEASURES: Estimated annualized incidence rates of genital human papillomavirus infection and Chlamydia infection. RESULTS: The estimated annualized incidence rates of genital human papillomavirus and Chlamydia infections were 2.2% and 1.5% respectively. Among the students who indicated being infected with genital human papillomavirus 59% were 18 to 21 years old (p < 0.05), 76% were women (p < 0.01) and 69% had more than one sexual partner (p < 0.01). No statistically significant associations were observed between age, sex and Chlamydia infection. On the other hand, 95% of the cases of Chlamydia infection were found among those who had more than one sexual partner (p < 0.01). CONCLUSION: University students continue to have sexual activities at risk for STDs and should be specifically targetted by general practitioners and health services in an effort to slow the spread of STDs.

Adolescent↗
PubMed1993

In vivo desensitization to leukotriene B4 (LTB4) in the rabbit. Inhibition of LTB4-induced neutropenia during intravenous infusion of LTB4.

Bolus injections of leukotriene B4 (LTB4) at 30-min intervals repeatedly induced similar profound and reversible neutropenias. In contrast, after a 30-min infusion of LTB4, the neutropenia induced by bolus injections of LTB4 was inhibited in a dose-dependent manner; a threshold inhibition was seen at the infusion rate of 10 ng LTB4/min/kg, whereas almost complete inhibition was observed at 50 ng LTB4/min/kg. Steady state arterial plasma concentrations of LTB4 increased proportionally to LTB4 infusion rate, ranging from 0.15 +/- 0.01 nM (control) to 2.80 +/- 0.16 nM (100 ng/min/kg). Extending the infusion period of LTB4 up to 330 min did not result in an enhanced inhibition of the neutropenia in response to bolus injections of LTB4. Reversibility of the desensitization was shown by an almost complete recovery of the neutropenic response within 30 min after cessation of the infusion. The desensitization achieved towards LTB4 showed some specificity, inasmuch as a profound and reversible neutropenia was observed in response to a bolus of either FMLP or C5a under conditions in which sensitivity to LTB4 was lost. These findings suggest that a specific desensitization to LTB4 is feasible in vivo and may constitute a useful approach, in addition to the use of 5-lipoxygenase inhibitors and LTB4 antagonists, to delineate the significance of LTB4 as a mediator of inflammation.

Animals↗
PubMed1993

Dynamic structure of Agrobacterium tumefaciens Ti plasmids.

Agrobacterium tumefaciens C58F is a variant of strain C58 which generates a high proportion of avirulent mutants in the presence of the virulence (vir) gene inducer acetosyringone. These mutants are altered in the Ti plasmid and do not respond to the acetosyringone signal (C. Fortin, E. W. Nester, and P. Dion, J. Bacteriol. 174:5676-5685, 1992). The physical organization of the Ti plasmid was compared in strain C58 and its variant. One feature distinguishing pTiC58F from its parent plasmid was the presence of the insertion element IS426. Three copies of this element were detected in the strain C58 chromosome, whereas two additional copies were found in strain C58F, including one copy in the Ti plasmid. This particular copy of IS426 was associated with the region of arginine and nopaline catabolism of pTiC58F. Most of the avirulent mutants recovered following growth of strain C58F in the presence of acetosyringone were complemented by clones carrying either virA or virG. Element IS426 was no longer found in the arginine and nopaline catabolism region of the Ti plasmids from the virA and virG mutants, but it resided in the particular KpnI fragment containing the modified vir locus. Behavior of a strain C58F derivative, which was inactivated in a chromosomal component required for the response to acetosyringone, was consistent with the possibility that vir gene induction is essential to the massive production of avirulent mutants.

Acetophenones↗
PubMed1993

Time estimation and concurrent nontemporal processing: specific interference from short-term-memory demands.

Previous studies have shown that the effect of concurrent nontemporal processing on time estimation may vary depending on the level of difficulty of the nontemporal task. This is commonly interpreted within the context of so-called distraction/interruption models of temporal processing, which propose that as concurrent task difficulty or complexity is increased, temporal processing receives less attention. We hypothesize that the effect of nontemporal processing does not depend on the level of difficulty as such, but rather on the extent to which the concurrent nontemporal task specifically involves processing in short-term memory. Four experiments were run in which the short-term memory requirements of concurrent tasks were systematically varied, although all of the tasks were of comparable levels of difficulty. In the first experiment, the effect of memory search on simultaneous temporal productions was proportional to the number of items to search. As with reaction time, produced intervals were shown to increase linearly with the number of items in the memorized set. In Experiment 2, a visual search involving some load on short-term memory interfered in the same way with time production, although to a lesser extent. The last two experiments showed that performing attention-demanding visual search tasks that did not involve short-term memory did not lengthen simultaneously produced time intervals. This suggests that interference of nontemporal processing on time processing may not be a matter of nonspecific general purpose attentional resources, but rather of concurrent short-term-memory processing demands.

Adult↗
PubMed1993

[Sensitivity and diagnostic value of mental load in a secondary task on tapping rate].

When executed concurrently with a primary task, finger tapping performance is commonly interpreted as an indication of the primary task mental workload. Higher load during tapping induces an increase in mean or variability of intertap intervals. Finger tapping sensitivity was tested with series of 13 taps at a tapping rate of one tap every two seconds. Concurrent primary task required subjects to search for a target item, presented after each tap, in a three digit memory set memorized before each series. Processing load was varied by including letter targets amongst positive and negative digit targets. Letter target recognition should require less processing than digit recognition. Results show mean intertap intervals for letter targets to be shorter than for negative digit targets. Furthermore, recognition of negative digit targets induces a longer mean intertap interval than positive targets. These data suggest that continuous finger tapping is a sensitive index of the mental workload originating from working memory processing requirements. However, analysis of practice data show that development of strategies at performing the dual task may mask the sensitivity of the finger tapping task.

Adult↗
PubMed1993

[Factors associated with at-risk anal relations in homosexual HIV-seropositive men].

This pilot study proposes an index to quantify the intensity of high-risk anal sex and presents factors associated with this practice among 65 homosexual men with HIV infection. All of them answered a self-administered questionnaire. Using multiple logistic regression, we first compared those who had had safe sex in the past six months to those who had had unsafe sex. Variables significantly associated with unsafe sex are: drugs and/or alcohol use with sex, and less favorable attitude towards condom use. Finally, multiple linear regression analysis among respondents who had had unsafe sex indicated that the following factors are associated with higher levels of unsafe sex: men between the ages of 32 and 38, satisfied with their social life, non-smokers, with a less favorable attitude towards condom use, and with few social relationships. These results must be interpreted with caution because of the small number of respondents.

Attitude↗
PubMed1992

Understanding physicians' decision to perform a clinical examination on an HIV seropositive patient.

The main purpose of this study was to identify the psychosocial factors explaining a physician's decision to perform a clinical (physical) examination of an HIV seropositive patient. Eight hundred seventy-nine physicians completed a questionnaire investigating psychosocial variables derived from the theories of Ajzen and Triandis. The mean intention to perform a clinical examination was quite positive (5.4 on a 7-point scale). The regression of intention on all variables yielded an adjusted R2 of .499. Among few significant predictors, by far the most important was the perceived norm among fellow physicians regarding performance of the clinical examination. It is concluded that educational interventions aimed at the physician population should focus on the social role and personal efficacy of physicians regarding this type of clinical examination rather than giving information concerning the low risk of contracting the HIV.

Attitude of Health Personnel↗
PubMed1992

Growth inhibition and loss of virulence in cultures of Agrobacterium tumefaciens treated with acetosyringone.

Acetosyringone, a phenolic inducer of the virulence (vir) genes of Agrobacterium tumefaciens, inhibited the growth of the nopaline-type strains T37 and C58 incubated under acidic conditions. In the course of a 6-day incubation with acetosyringone, avirulent clones were produced in different proportions by strains T37 and C58 and also by a spontaneous variant of strain C58, denominated C58F. The proportion of avirulent clones in acetosyringone-treated cultures often exceeded 50% for strains T37 and C58F and was of the order of 1% for strain C58. Control cultures not exposed to acetosyringone did not yield avirulent clones. Two other vir inducers, sinapinic acid and syringaldehyde, also inhibited growth and promoted accumulation of avirulent clones in cultures of strains C58F and T37. On the other hand, various acetosyringone analogs reported not to induce the vir genes did not act as growth inhibitors. All of the T37 and most of the C58F avirulent clones examined still carried a Ti plasmid. In all instances examined, avirulent clones still carrying a Ti plasmid were mutated in this plasmid. Mutants of strain C58F lacked the capacity to induce a virB::lacZ fusion in the presence of acetosyringone.

Acetophenones↗