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F Guerrin

Publications and source records attributed to F Guerrin.

At least 19 recordsLinked to original sources
PubMed2001

Knowledge representation and qualitative simulation of salmon redd functioning. Part I: qualitative modeling and simulation.

This work aims at representing empirical knowledge of freshwater ecologists on the functioning of salmon redds (spawning areas of salmon) and its impact on mortality of early stages. For this, we use Qsim, a qualitative simulator. In this first part, we provide unfamiliar readers with the underlying qualitative differential equation (QDE) ontology of Qsim: representing quantities, qualitative variables, qualitative constraints, QDE structure. Based on a very simple example taken of the salmon redd application, we show how informal biological knowledge may be represented and simulated using an approach that was first intended to analyze qualitatively ordinary differential equations systems. A companion paper (Part II) gives the full description and simulation of the salmon redd qualitative model. This work was part of a project aimed at assessing the impact of the environment on salmon populations dynamics by the use of models of processes acting at different levels: catchment, river, and redds. Only the latter level is dealt with in this paper.

Animals↗
PubMed2001

Knowledge representation and qualitative simulation of salmon redd functioning. Part II: qualitative model of redds.

This paper describes a qualitative model of the functioning of salmon redds (spawning areas of salmon) and its impact on mortality rates of early stages. For this, we use Qsim, a qualitative simulator, which appeared adequate for representing available qualitative knowledge of freshwater ecology experts (see Part I of this paper). Since the number of relevant variables was relatively large, it appeared necessary to decompose the model into two parts, corresponding to processes occurring at separate time-scales. A qualitative clock allows us to submit the simulation of salmon developmental stages to the calculation of accumulated daily temperatures (degree-days), according to the clock ticks and a water temperature regime set by the user. Therefore, this introduces some way of real-time dating and duration in a purely qualitative model. Simulating both sub-models, either separately or by means of alternate transitions, allows us to generate the evolutions of variables of interest, such as the mortality rates according to two factors (flow of oxygenated water and plugging of gravel interstices near the bed surface), under various scenarios.

Animals↗
PubMed1994

Qualitative Reasoning methods for CELSS modeling.

Qualitative Reasoning (QR) is a branch of Artificial Intelligence that arose from research on engineering problem solving. This paper describes the major QR methods and techniques, which, we believe, are capable of addressing some of the problems that are emphasized in the literature and posed by CELSS modeling, simulation, and control at the supervisory level.

Artificial Intelligence↗
PubMed1994

Comparison of two field tests to estimate maximum aerobic speed.

The measurement of maximal aerobic speed (MAS) and the prediction of maximal oxygen uptake (VO2 max) by means of field tests were carried out on 17 students studying physical education. The subjects underwent a continuous multi-stage track test (Léger and Boucher, 1980), shuttle test (Léger et al., 1984) and VO2 max measurement on a treadmill. The VO2 max values estimated using the track test (56.8 +/- 5.8 ml kg-1 min-1) were not significantly different from the values measured in the treadmill test (56.8 +/- 7.1 ml kg-1 min-1), but were higher than those estimated using the shuttle test (51.1 +/- 5.9 ml kg-1 min-1). The maximal nature of the tests was checked by measurement of heart rate and lactate concentration, taken within 2 min post-test. The means of the MAS observed in the track test (15.8 +/- 1.9 km h-1) and in the treadmill test (15.9 +/- 2.6 km h-1) were not significantly different (P > 0.10). The mean of the shuttle test MAS (13.1 +/- 1 km h-1) was significantly lower (P < 0.01) than those of the other tests. However, the MAS of the shuttle test and track test are linked. The equation for linear regression between MAS values in these two tests is MAStrack = 1.81 x MASshuttle -7.86 (r = 0.91), allowing estimation of one of these MAS values when the other is known. Thus these values may be used within diversified training.

Adolescent↗
PubMed1992

IMOCUR stimulates production of immunoglobulins; preliminary results concerning a correlation between in vitro and in vivo experiments.

The bacterial extract IMOCUR is described as an in vivo stimulant of antibody production during animal testing and human clinical trials. Using a slightly modified procedure (13) dealing with in vitro immunoglobulin production by C57B1/6 mouse spleen cells, we have shown that IMOCUR potentiates spontaneous IgM production. In order to explore the putative relation between this in vitro activity and the current in vivo control test (stimulation of plaque-forming cell production after sheep red blood cell injection to Balb/c mouse), we have assayed 10 lyophilisates in vitro and in vivo before and after heat inactivation (80 degrees C, 7 days in a saturated water atmosphere). Results have shown that this treatment inhibits, respectively, totally and partially in vivo and in vitro activities. Thus the in vitro technique seems to be appropriate for the control of activity of the various batches of IMOCUR. Experiments are under way to clarify the mathematical correlation which may exist between the in vitro and in vivo experiments.

Adjuvants, Immunologic↗
PubMed1987

[Splenic complications of chronic pancreatitis. Clinical and experimental study].

Splenic complications of chronic pancreatitis appear to be less exceptional than is usually accepted, particularly since preoperative diagnosis has been facilitated by ultrasound and abdominal scan imaging. Complications noted in 37 cases were: infarcts (2 cases), hematoma or false blood cysts (26 cases) and rupture (9 cases). The splenic infarcts were revealed by digestive hemorrhage, the false blood cysts of spleen by a painful mass in left hypochondrium associated with pleural effusion and rupture of spleen by an acute hemoperitoneum. Treatment included splenectomy in 19 cases, splenectomy caudal pancreatectomy in 17 cases and drainage of a splenic hematoma in one patient. Operative mortality was 16.2% and the long-term prognosis was poor and related to underlying condition. Data from an experimental study suggest that the effect of an episode of acute pancreatitis on the splenic pedicle is the most important physiopathologic factor. A hemorrhagic infarct or infarction of splenic parenchyma are common starting points for all clinicopathologic forms described.

Animals↗
PubMed1980

Bronchodilating drugs and airway reactivity.

Tests with various bronchodilator drugs are utilized in the screening of airway hyperactivity in clinical practice. Bronchodilator tests making use of Salbutamol (Ventoline) as aerosols and by mouth, SCH 1000 as inhalations, Thiazinamium (Multergan) by mouth were performed in 42 patients suffering from bronchial asthma or of chronic obstructive disease, who were investigated by measurement of FEV1, Raw, MEFR. The treatment tests have a variable but significant potency in bronchospastic diseases. Taking into consideration one, two or three signs of bronchodilation, the improvement of FEV1, of MEFR, of airway resistance, the decreasing efficacy of the drug is as follows: SCH 1000 aerosol, Salbutamol aerosol, Salbutamol per os, Thiazinamium per os. The measurement of Raw is the more sensitive exploration to detect the bronchodilator effect of these drugs. The observed bronchodilation may be considered as a criterion of hyperreactivity of the bronchial airways. The differences between the effectiveness of the drugs may allow a better knowledge of the mechanisms of the bronchial airway reactivity and of the treatment of bronchospastic diseases.

Adult↗
PubMed1980

[Bronchial hyperreactivity in miners with pneumoconiosis].

Hyperreactivity of a pneumoconiotic origin may manifest itself either at the level of the lung parenchyma or at the bronchial site. It may induce either clinical patterns, such as those which occur in the bronchospastic disease in coal-miners, or be the cause of functional disturbances in particular positive responses to aspecific challenge tests with acetylcholine; finally it may produce some radiologic or endoscopic changes in the lungs. The precise role of the causal agent of pneumoconiosis is difficult to assess by comparison with the role of bronchitis, more precisely that of the small airway disease, or the action of the numerous air pollutants or eventually the intervention of an individual predisposition. Bronchial hyperreactivity in pneumoconiotics may not be assimilated to a purely immunological phenomenon. The various changes induced in the lungs by the pneumoconiosis, above all at the level of the bronchi, contribute to a multifactorial etiology of this hyperreactivity. A better understanding of the phenomenon might result from further biological investigation of the respiratory tract.

Acetylcholine↗