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Biomedical subjects

H Beaulieu

Publications and source records attributed to H Beaulieu.

3 recordsLinked to original sources

A mathematical programming approach for scheduling physicians in the emergency room.

Preparing a schedule for physicians in the emergency room is a complex task, which requires taking into account a large number of (often conflicting) rules, related to various aspects: limits on the number of consecutive shifts or weekly hours, special rules for night shifts and weekends, seniority rules, vacation periods, individual preferences,... In this paper, we present a mathematical programming approach to facilitate this task. The approach models the situation in a major hospital of the Montreal region (approximately 20 physicians are members of the working staff). We show that the approach can significantly reduce the time and the effort required to construct a six-month schedule. A human expert, member of the working staff, typically requires a whole dedicated week to perform this task, with the help of a spreadsheet. With our approach, a schedule can be completed in less than one day. Our approach also generates better schedules than those produced by the expert, because it can take into account simultaneously more rules than any human expert can do.

Emergency Service, Hospital↗

Interaction of mammalian neprilysin with binding protein and calnexin in Schizosaccharomyces pombe.

Neutral endopeptidase (neprilysin or NEP, EC 3.4.24.11) is a zinc metallo-endopeptidase expressed in many eukaryotic cell types and displaying several important physiological roles. In the brain (and central nervous system), this enzyme is involved in the molecular mechanism of pain by its action in the degradation of enkephalin molecules. In the kidney, NEP is implicated in the degradation of regulatory factors involved in the control of arterial pressure, including atrial natriuretic peptide and bradykinin. In this study we assessed the potential of the fission yeast Schizosaccharomyces pombe to overproduce rabbit NEP and secreted NEP (sNEP, a soluble derivative of this integral membrane protein). Both recombinant NEP and sNEP were produced at high levels (5 mg/l) in this system. Enzymic studies revealed that these recombinant proteins were fully active and exhibit kinetic parameters similar to those of the bona fide enzyme. Immunofluorescence microscopy and enzymic assays demonstrated that recombinant NEP is correctly targeted to the cell membrane. Furthermore, co-immunoprecipitation studies showed that folding intermediates of NEP and sNEP, produced in S. pombe, interact in the endoplasmic reticulum (ER) with binding protein (BiP) and calnexin (Cnx1p). The amount of sNEP coprecipitated with both BiP and Cnx1p augmented when cells were subjected to various stresses causing the accumulation of unfolded proteins in the ER. The interactions of NEP with BiP and Cnx1p were, however, more refractive to the same stresses.

Animals↗

Attempts at aerosol control in a turkey rearing confinement with negative air ionization.

Aerosol control is a significant problem in agriculture and industry. Two separate studies were conducted to determine the effectiveness of a "negative air ionization" system in aerosol control. The first study was conducted with a turkey "brooder" barn and a control for a six-week period. The second study was conducted with a turkey "grow-out" barn and a control for a twelve-week period. Sampling parameters for both studies included environmental aerosol sampling, ion imbalance measurements, relative humidity, temperature and barometric pressure measurements and daily turkey mortality. Study two also included post study bird weights. Results of sampling parameters were consistent between study one and study two. No significant difference was found between test and control total average aerosol concentration for both studies. Ion imbalance measurements served to indicate that test environments were negatively ionized while control environments experienced normal environmental conditions. Meteorological parameters did not significantly affect aerosol concentrations. Normal variations in bird mortality were observed in the first study, but death rates increased with ionization in the latter. Overall, it was determined that the "negative air ionization" could not be considered as an effective means of aerosol control in turkey rearing confinements.

Aerosols↗