La décentralisation intramétropolitaine des activités économiques dans la région de Montréal, 1981-1991

Depuis la Deuxième Guerre mondiale, les métropoles nord-américaines ont connu plusieurs vagues de décentralisation, c'est-à-dire de déplacement des personnes et des activités économiques de la ville centrale vers les banlieues : la population, les services à la consommation, les industries manufacturières, les activités de bureaux standardisées (les back offices). Plus récemment, certains auteurs américains ont commencé à parler d'une « nouvelle suburbanisation » impliquant la création des edge cities; ce phénomène touche surtout les activités du tertiaire moteur. Le but de cet article est de mesurer l'ampleur de la décentralisation des activités économiques dans la région métropolitaine de Montréal pendant la période 1981-1991. Cette étude utilise la base de données de Dun & Bradstreet qui, en raison de son découpage géographique très détaillé, permet de mieux saisir la dynamique de décentralisation dans la région montréalaise. Les résultats montrent que, même si dans son ensemble la ville de Montréal perd du terrain au profit des zones périphériques, son centre-ville reste très fort sur le plan économique, surtout au niveau du tertiaire moteur.Since the Second World War, North American metropolitan areas have experienced several waves of decentralization from the central city towards the suburbs : population, consumer services, manufacturing, and standardized office functions (« back offices »). Recently, several American authors have begun to speak of a « new suburbanization » involving the shift of high order service activities towards « edge cities ». This article examines the extent to which economic activities have undergone a similar decentralization within the Montréal metropolitan region over the period 1981-1991. The study uses Dun & Bradstreet data which, due to a very fine level of spatial disaggregation, permits a detailed analysis of the dynamics of decentralization in the Montréal region. The results indicate that although the City of Montréal, as a whole, is losing ground to the peripheral zones, its central business district remains very strong economically, especially where high order service functions are concerned

The salivary secretome of the biting midge, Culicoides sonorensis

Culicoides biting midges (Diptera: Ceratopogonidae) are hematophagous insects with over 1400 species distributed throughout the world. Many of these species are of particular agricultural importance as primary vectors of bluetongue and Schmallenberg viruses, yet little is known about Culicoides genomics and proteomics. Detailed studies of members from other blood-feeding Dipteran families, including those of mosquito (Culicidae) and black fly (Simuliidae), have shown that protein components within the insect’s saliva facilitate the blood feeding process. To determine the protein components in Culicoides sonorensis midges, secreted saliva was collected for peptide sequencing by tandem mass spectrometry. Forty-five secreted proteins were identified, including members of the D7 odorant binding protein family, Kunitz-like serine protease inhibitors, maltase, trypsin, and six novel proteins unique to C. sonorensis. Identifying the complex myriad of proteins in saliva from blood-feeding Dipteran species is critical for understanding their role in blood feeding, arbovirus transmission, and possibly the resulting disease pathogenesis

Adiabatic reduction near a bifurcation in stochastically modulated systems

We re-examine the procedure of adiabatic elimination of fast relaxing variables near a bifurcation point when some of the parameters of the system are stochastically modulated. Approximate stationary solutions of the Fokker-Planck equation are obtained near threshold for the pitchfork and transcritical bifurcations. Stochastic resonance between fast variables and random modulation may shift the effective bifurcation point by an amount proportional to the intensity of the fluctuations. We also find that fluctuations of the fast variables above threshold are not always Gaussian and centered around the (deterministic) center manifold as was previously believed. Numerical solutions obtained for a few illustrative examples support these conclusions.Comment: RevTeX, 19 pages and 16 figure

Fluid Physics in a Fluctuating Acceleration Environment

We summarize several aspects of an ongoing investigation of the effects that stochastic residual accelerations (g-jitter) onboard spacecraft can have on experiments conducted in a microgravity environment. The residual acceleration field is modeled as a narrow band noise, characterized by three independent parameters: intensity (g(exp 2)), dominant angular frequency Omega, and characteristic correlation time tau. Realistic values for these parameters are obtained from an analysis of acceleration data corresponding to the SL-J mission, as recorded by the SAMS instruments. We then use the model to address the random motion of a solid particle suspended in an incompressible fluid subjected to such random accelerations. As an extension, the effect of jitter on coarsening of a solid-liquid mixture is briefly discussed, and corrections to diffusion controlled coarsening evaluated. We conclude that jitter will not be significant in the experiment 'Coarsening of solid-liquid mixtures' to be conducted in microgravity. Finally, modifications to the location of onset of instability in systems driven by a random force are discussed by extending the standard reduction to the center manifold to the stochastic case. Results pertaining to time-modulated oscillatory convection are briefly discussed

Comparison of two methods for measuring the pubococcygeal line from sagittal-plane magnetic resonance imaging

Aims The pubococcygeal line (PCL) is an important reference line for determining measures of pelvic organ support on sagittal-plane magnetic resonance imaging (MRI); however, there is no consensus on where to place the posterior point of the PCL. As coccyx movement produced during pelvic floor muscle (PFM) contractions may affect other measures, optimal placement of the posterior point is important. This study compared two methods for measuring the PCL, with different posterior points, on T2-weighted sagittal MRI to determine the effect of coccygeal movement on measures of pelvic organ support in older women. Methods MRI of the pelvis was performed in the midsagittal plane, at rest and during PFM contractions, on 47 community-dwelling women 60 and over. The first PCL was measured to the tip of the coccyx (PCLtip) and the second to the sacrococcygeal joint (PCLjnt). Four measures of pelvic organ support were made using each PCL as the reference line: urethrovesical junction height, uterovaginal junction height, M-line and levator plate angle. Results During the PFM contraction the PCLtip shortened and lifted (P  0.05). The changes in the four measures of pelvic organ support were smaller when measured relative to the PCLtip as compared to those to the PCLjnt (P < 0.001). Conclusions Coccyx movement affected the length and position of the PCLtip, which resulted in underestimates of the pelvic-organ lift produced by the PFM contraction. Therefore, we recommend that the PCL be measured to the sacrococcygeal joint and not to the tip of the coccy

Changes in urethral sphincter size following rehabilitation in older women with stress urinary incontinence

Introduction and hypothesis The purpose of this study was to evaluate the effects of a pelvic floor muscle (PFM) rehabilitation program on the striated urethral sphincter in women over 60 years with stress urinary incontinence (SUI). We hypothesized that the PFM rehabilitation program would also exercise the striated urethral sphincter and that this would be demonstrated by hypertrophy of the sphincter on magnetic resonance imaging (MRI). Methods Women with at least weekly episodes of SUI were recruited. Participants were evaluated before and after a 12-week group PFM rehabilitation intervention with T2-weighted fast-spin-echo MRI sequences recorded in the axial plane at rest to assess urethral sphincter size. Data on SUI symptoms and their bother were also collected. No control group was included. Results Seventeen women participated in the study. The striated urethral sphincter increased significantly in thickness (21 %, p < 0.001), cross-sectional area (20 %, p = 0.003), and volume (12 %, p = 0.003) following the intervention. The reported number of incontinence episodes and their bother also decreased significantly. Conclusions This study appears to demonstrate that PFM training for SUI also trains the striated urethral sphincter and that improvement in incontinence signs and symptoms is associated with sphincter hypertrophy in older women with SUI. These findings support previous ultrasound (US) data showing an increase in urethral cross-sectional area following PFM training and extend the previous findings by more specifically assessing the area of hypertrophy and by demonstrating that older women present the same changes as younger women when assessed using MRI data

Wage losses in the year after breast cancer: Extent and determinants among Canadian women

This article is available open access through the publisher’s website at the link below. © The Author 2008.Background - Wage losses after breast cancer may result in considerable financial burden. Their assessment is made more urgent because more women now participate in the workforce and because breast cancer is managed using multiple treatment modalities that could lead to long work absences. We evaluated wage losses, their determinants, and the associations between wage losses and changes for the worse in the family's financial situation among Canadian women over the first 12 months after diagnosis of early breast cancer. Methods - We conducted a prospective cohort study among women with breast cancer from eight hospitals throughout the province of Quebec. Information that permitted the calculation of wage losses and information on potential determinants of wage losses were collected by three pretested telephone interviews conducted over the year following the start of treatment. Information on medical characteristics was obtained from medical records. The main outcome was the proportion of annual wages lost because of breast cancer. Multivariable analysis of variance using the general linear model was used to identify personal, medical, and employment characteristics associated with the proportion of wages lost. All statistical tests were two-sided. Results - Among 962 eligible breast cancer patients, 800 completed all three interviews. Of these, 459 had a paying job during the month before diagnosis. On average, these working women lost 27% of their projected usual annual wages (median = 19%) after compensation received had been taken into account. Multivariable analysis showed that a higher percentage of lost wages was statistically significantly associated with a lower level of education (Ptrend = .0018), living 50 km or more from the hospital where surgery was performed (P = .070), lower social support (P = .012), having invasive disease (P = .086), receipt of chemotherapy (P < .001), self-employment (P < .001), shorter tenure in the job (Ptrend < .001), and part-time work (P < .001). Conclusion - Wage losses and their effects on financial situation constitute an important adverse consequence of breast cancer in Canada.The Canadian Breast Cancer Research Alliance, Canadian Institutes of Health Research, and Fondation de l’Université Laval

Pelvic floor morphometry : a predictor of success of pelvic floor muscle training for women with stress and mixed urinary incontinence

Introduction and hypothesis: The aim of this study was to determine if pelvic floor muscle (PFM) morphometry at baseline, as measured by MRI, can predict response to PFM training in women with stress or mixed urinary incontinence (UI). Methods: This study was a prospective quasi-experimental pre-test, post-test cohort study of women with UI, aged 60 years and older. All participants completed a baseline assessment of UI severity and impact, using the 72-h bladder diary and the Incontinence Impact Questionnaire. They underwent a pelvic MRI examination to assess the PFM anatomy. Women then participated in a 12-week PFM training program. Finally, they attended a post intervention assessment of UI severity and impact. The association between morphometry and PFM training response was assessed by univariate analysis, multivariate analysis, and receiver operating characteristic (ROC) curve analysis. Results: The urethro-vesical junction height at rest, as measured by MRI before treatment, was associated with response to PFM training both on univariate (p ≤ 0.005) and multivariate analyses (p = 0.007). The area under the ROC curve was 0.82 (95% confidence interval [CI]: 0.67-0.96). Using a cut-off point of 11.4 mm, participants' response to PFM training was predicted with a sensitivity of 77% and a specificity of 83%. Incontinent women with a urethro-vesical junction height above this threshold were 35% more likely to respond to PFM training (OR 1.35; 95% CI: 1.08-1.67). Conclusion: In older women with UI, a urethro-vesical junction height at rest of at least 11.4 mm appears to be predictive of PFM training response