Université de Sherbrooke
  • Sherbrooke, Québec, Canada
Recent publications
The present study addresses the question of what effect wall thickness would have on the thermo-mechanical properties of corrugated HDPE pipes aging under freeze–thaw cycles in Quebec province, from the surface to its interior. Five commercial corrugated HDPE pipes for transportation infrastructure applications aging within 14 years from different locations in Quebec province (Canada) were examined. The impact of wall thickness (4.50, 7.00, 7.80, 8.90, and 10.40 mm) on decomposition, thermal properties, and long-term modulus of pipes was reported by thermal analysis techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Dynamic Mechanical Analysis (DMA). The antioxidant depletion at the exterior and interior walls of pipes was investigated by oxidation induction time (OIT) measurements. The results indicate that all investigated pipes meet a minimum 20-min OIT requirement where the antioxidant content is sufficient to withstand oxidation. The antioxidants extraction process occurred through the wall thickness which explains the significant difference in the thermal properties of pipes at the exterior and interior walls. However, the change of long-term modulus to variable wall thickness is relatively small.
Fiber Reinforced Polymer (FRP) found to be effective as an alternative reinforcement material for concrete structures in severe environmental conditions. Recent research with full FRP internal reinforcement has proven its effectiveness subjected to simulated seismic loading. However, limited research is available for the hybrid reinforced concrete columns. Where the longitudinal reinforcement is steel and transverse reinforcement is Glass FRP (GFRP). This paper accesses the results of an experimental study of the two full-scale rectangular columns subjected to quasi-static cyclic loading. The columns have 400 × 400 mm cross-sectional dimension with an effective height of 1650 mm. One of the columns is completely reinforced with GFRP reinforcement; and the other column is a hybrid reinforced column reinforced with longitudinal steel reinforcement and confined with GFRP lateral reinforcement. The test results are presented and discussed in terms of general behavior focusing on failure progression and strength of column. Dissipated energy for individual cycles and cumulative dissipative energy was computed based on the experimental lateral load–displacement hysteresis response. Longitudinal bar type significantly affects the dissipated energy and equivalent hysteresis damping ratio was observed.
The incidence of musculoskeletal disorders (MSD) in the healthcare professional population is concerning. In particular, the high incidence of back injuries is an issue for nurses. Although many MSD prevention initiatives are being implemented, these practices are not succeeding in reducing MSDs. Why are these efforts struggling to close the gap between knowledge and practice? This article aims to report on individual and organizational factors that may influence nurses' implementation of MSD prevention practices. A survey was sent to nurses in the Quebec health and social services network. A total of 399 questionnaires were completed and analyzed. The results revealed that nurses have the required knowledge on MSD prevention practices, but have difficulty applying them in their professional context. It would appear that successful implementation of MSD prevention practices relies mainly on organizational factors, including management support, organizational culture, feedback mechanisms, and training that is adapted to the work environment.
Transcriptional pausing occurs across the bacterial genome but the importance of this mechanism is still poorly understood. Only few pauses were observed during the previous decades, leaving an important gap in understanding transcription mechanisms. Using the well-known Escherichia coli hisL and trpL pause sites as models, we describe here the relation of pause sites with upstream RNA structures suspected to stabilize pausing. We find that the transcription factor NusA influences the pause half-life at leuL, pheL and thrL pause sites. Using a mutagenesis approach, we observe that transcriptional pausing is affected in all tested pause sites, suggesting that the upstream RNA sequence is important for transcriptional pausing. Compensatory mutations assessing the presence of RNA hairpins did not yield clear conclusions, indicating that complex RNA structures or transcriptional features may be playing a role in pausing. Moreover, using a bioinformatic approach, we explored the relation between a DNA consensus sequence important for pausing and putative hairpins among thousands of pause sites in E. coli. We identified 2125 sites presenting hairpin-dependent transcriptional pausing without consensus sequence, suggesting that this mechanism is widespread across E. coli. This study paves the way to understand the role of RNA structures in transcriptional pausing.
Background: Foot involvement is a major manifestation of psoriatic arthritis (PsA) and can lead to severe levels of foot pain and disability and impaired functional mobility and quality of life. Gait spatiotemporal parameters (STPs) and gait variability, used as a clinical index of gait stability, have been associated with several adverse health outcomes, including risk of falling, functional decline, and mortality in a wide range of populations. Previous studies showed some alterations in STPs in people with PsA. However, gait variability and the relationships between STPs, gait variability and self-reported foot pain and disability have never been studied in these populations. Body-worn inertial measurement units (IMUs) are gaining interest in measuring gait parameters in clinical settings. Objectives: To assess STPs and gait variability in people with PsA using IMUs, to explore their relationship with self-reported foot pain and function and to investigate the feasibility of using IMUs to discriminate patient groups based on gait speed-critical values. Methods: Twenty-one participants with PsA (age: 53.9 ± 8.9 yrs.; median disease duration: 6 yrs) and 21 age- and sex-matched healthy participants (age 54.23 ± 9.3 yrs) were recruited. All the participants performed three 10-m walk test trials at their comfortable speed. STPs and gait variability were recorded and calculated using six body-worn IMUs and Mobility Lab software (APDM®). Foot pain and disability were assessed in participants with PsA using the foot function index (FFI). Results: Cadence, gait speed, stride length, and swing phase were significantly lower, while double support was significantly higher, in the PsA group (p < 0.006). Strong correlations between STPs and the FFI total score were demonstrated (|r| > 0.57, p < 0.006). Gait variability was significantly increased in the PsA group, but it was not correlated with foot pain or function (p < 0.006). Using the IMUs, three subgroups of participants with PsA with clinically meaningful differences in self-reported foot pain and disability were discriminated. Conclusion: STPs were significantly altered in participants with PsA, which could be associated with self-reported foot pain and disability. Future studies are required to confirm the increased gait variability highlighted in this study and its potential underlying causes. Using IMUs has been useful to objectively assess foot function in people with PsA. Trial registration: ClinicalTrials.gov , NCT05075343 , Retrospectively registered on 29 September 2021.
Background Benefits of physical activity has been shown for adolescents; however, there is a decline trend in number of adolescents meeting current WHO recommendations. This trend underlines the importance of identifying factors associated with adolescents’ physical activity level (PAL) with considerations of regional and cultural differences to plan and implement effective policies. Therefore, the aim of this study was to determine personal, ecological, and social factors associated with PAL and sport participation in Turkish adolescents aged 11–14 years. A cross-sectional study was conducted by including 996 adolescents aged between 11 and 14 years from 39 secondary schools in İstanbul, Turkey. Logistic regression analyses performed to identify the significant personal (age, gender, sleep time, screen time, BMIz score, having siblings), ecological (presence of playground, type of school transportation), and social (family income, engaging a physical activity with family, and preferred activity at school breaks) predictors of PAL and sport participation. Results Adolescents who were active during break time at school ( p < 0.001), engaging a physical activity with family ( p < 0.001), and did not have a sibling ( p = 0.029) were more likely to be physically active. Adolescents behaved active during break time at school ( p < 0.001), had a playground at home ( p < 0.001), spending time with family for physical activity ( p < 0.001), and did not have a sibling ( p = 0.021) were more likely to participate in a sport activity. Conclusions Predictors of PAL in this study indicates the need to promote active break time in school, increased physical activity time with family, and to design environmental policies to increase number of playgrounds.
Background Acute airway angioedema commonly occurs through two distinct mechanisms: histamine- and bradykinin-dependent. Although they respond to distinct treatments, these two potentially life-threatening states present similarly. Poor recognition of the bradykinin-dependent pathway leads to treatment errors in the emergency department (ED), despite the availability of multiple pharmacologic options for hereditary angioedema (HAE) and other forms of bradykinin-induced angioedema. Here, we consider the pathophysiology and clinical features of bradykinin-induced angioedema, and we present a systematic literature review exploring the effectiveness of the available therapies for managing such cases. Methods PubMed searches using ‘emergency’, ‘bradykinin’ and various therapeutic product names identified studies reporting the efficacy of treatments for bradykinin-induced angioedema in the ED setting. In all, 22 studies met prespecified criteria and are analysed here. Findings Whereas histamine-induced angioedema has a faster onset and often presents with urticaria, bradykinin-induced angioedema is slower in onset, with greater incidence of abdominal symptoms. Acute airway angioedema in the ED should initially be treated with anaphylactic protocols, focusing on airway management and treatment with epinephrine, antihistamine and systemic steroids. Bradykinin-induced angioedema should be considered if this standard treatment is not effective, despite proper dosing and regard of beta-adrenergic blockade. Therapeutics currently approved for HAE appear as promising options for this and other forms of bradykinin-induced angioedema encountered in the ED. Conclusion Diagnostic algorithms of bradykinin-induced angioedema should be followed in the ED, with early use of approved therapies to improve patient outcomes.
In many countries, osteoporosis is predominantly managed by primary care physicians; however, management after a fragility fracture has not been widely investigated. We describe osteoporosis care gaps in a real-world patient cohort. Our findings help inform initiatives to identify and overcome obstacles to effective management of patients after fragility fracture. Purpose A fragility fracture is a major risk factor for subsequent fracture in adults aged ≥ 50 years. This retrospective observational study aimed to characterize post-fracture management in Canadian primary care. Methods A total of 778 patients with an index fragility fracture (low-trauma, excluding small bones) occurring between 2014 and 2016 were identified from medical records at 76 primary care centers in Canada, with follow-up until January 2018. Results Of 778 patients (80.5% female, median age [IQR] 73 [64–80]), 215 were on osteoporosis treatment and 269 had osteoporosis diagnosis recorded prior to their index fracture. The median follow-up was 363 (IQR 91–808) days. Of patients not on osteoporosis treatment at their index fracture, 60.2% ( n = 339/563) remained untreated after their index fracture and 62.2% ( n = 23/37) continued untreated after their subsequent fracture. After their index fracture, fracture risk assessment (FRAX or CAROC) was not performed in 83.2% ( n = 647/778) of patients, and 59.9% ( n = 466/778) of patients did not receive bone mineral density testing. Of patients without osteoporosis diagnosis recorded prior to their index date, 61.3% ( n = 300/489) remained undiagnosed after their index fracture. At least one subsequent fracture occurred in 11.5% ( n = 86/778) of patients. Conclusion In the primary care setting, fragility fracture infrequently resulted in osteoporosis treatment or fracture risk assessment, even after multiple fragility fractures. These results suggest a fragility fracture is not recognized as a major risk factor for subsequent fracture and its occurrence does not prompt primary care physicians to intervene. These data urge initiatives to identify and overcome obstacles to primary care physicians’ effective management of patients after fragility fractures.
This study aims to examine the trends in the sustainability performance indicators disclosed in sustainability reports by Canadian companies. Our sample is comprised of eight companies in four sectors and our observations cover a 19-year period. The results of our analysis show a general increase over time of sustainability performance indicators disclosed, as well as varying degrees of coverage of the three sustainability dimensions. While the focus was more on environmental performance in the early 2000s, social performance indicators, such as employment practices and human rights, have now gained more traction. In addition, the scope of sustainability performance indicators disclosed in sustainability reports reached a plateau around 2010. Our results highlight the need for a standardised approach to sustainability reporting that would help overcome the shortcomings of voluntary initiatives and improve the overall comparability of voluntary reporting mechanisms.
Background The LH surge is a pivotal event that triggers multiple key ovarian processes including oocyte maturation, cumulus expansion, follicular wall rupture and luteinization of mural granulosa and theca cells. Recently, LH-dependent activation of the Hippo signaling pathway has been shown to be required for the differentiation of granulosa cells into luteal cells. Still, the precise interactions between Hippo and LH signaling in murine granulosa cells remain to be elucidated. Methods To detect the expression of effectors of the Hippo pathway, western blot, immunohistochemical and RT-qPCR analyses were performed on granulosa cells treated with LH in vitro or isolated from immature mice treated with eCG and hCG. Cultured granulosa cells were pretreated with pharmacologic inhibitors to identify the signaling pathways involved in Hippo regulation by LH. To study the roles of Yap1 and Taz in the regulation of the LH signaling cascade, RT-qPCR and microarray analyses were done on granulosa cells from Yap1 f/f ; Taz f/f mice treated with an adenovirus to drive cre expression. RT-qPCR was performed to evaluate YAP1 binding to the Areg promoter following chromatin immunoprecipitation of granulosa cells collected from mice prior to or 60 min following hCG treatment. Results Granulosa cells showed a transient increase in LATS1, YAP1 and TAZ phosphorylation levels in response to the ovulatory signal. This Hippo activation by LH was mediated by protein kinase A. Furthermore, Yap1 and Taz are required for the induction of several LH target genes such as Areg , Pgr and Ptgs2 , and for the activation of the ERK1/2 pathway. Consistent with these results, there was a substantial overlap between genes that are upregulated by LH and those that are downregulated following loss of Yap1 / Taz, highlighting a major role for Hippo in mediating LH actions in the ovulation process. Finally, we showed that there is a marked recruitment of YAP1 to the Areg promoter of granulosa cells in response to hCG stimulation. Conclusions Overall, these results indicate that Hippo collaborates with the cAMP/PKA and ERK1/2 pathways to participate in the precise regulation of the LH cascade, and that Areg , as a direct transcriptional target of YAP1, is involved in mediating its actions in the ovary.
Translational research aims at reducing gaps between fundamental scientific discoveries and real-world applications. However, the trajectory of most scientific discoveries along the translation research continuum remains highly complex. Logic models are powerful tools that can help reduce this complexity. They are often used to lay out road maps and depict the relationship between activities and their intended effects. Few if any existing tools have been designed to guide the implementation and evaluation of collaborative models between community-based primary health care and biomedical research. To address this gap, we developed a logic model in two stages: 1) a literature review; and 2) the drafting and revision of the model by experts in the field. We describe its components, including objectives, inputs, activities, target groups, outputs, and results for a collaborative model involving fundamental biomedical research and primary health care practices. Our proposed logic model provides a road map that has the potential to reduce the complexity faced by translational research in chronic diseases by providing guidelines for decision-makers. Future work should attempt to validate the model before its broad-based implementation.
The idea that innovative work behavior (IWB) can be a source of well-being is a prominent theme in the innovation literature. However, the potential bright side of IWB for employee well-being is overlooked. Building on the egosystem-ecosystem perspective, we theorize and empirically test individual differences in two interpersonal goals, namely compassionate and self-image goals, as boundary conditions upon which IWB can positively relate to flourishing. Using cross-lagged data from 477 employees from different organizations in three countries (Brazil, Canada, and Portugal), we found that IWB had a positive relationship with flourishing only for employees with high compassionate goals and low levels of self-image goals. We discuss the implications of these findings for research and practice.
This manuscript proposes a hybrid machine learning approach to estimate the battery output power and remaining driving range in a battery electric vehicle (BEV). These two metrics are among the most significant factors in the market penetration of BEVs, specifically in countries with harsh winters. The proposed hybrid method comprises a recurrent dynamic network, nonlinear autoregressive with exogenous inputs (NARX), and a recursive algorithm, Kalman filter (KF). The NARX neural network utilizes the information from the weather, the vehicle's speed, and road conditions to predict the battery output power, and the remaining driving range. KF, unlike the other similar studies, is employed to account for the dynamic changes in different road conditions by providing the vehicle rolling resistance and aerodynamic drag coefficient estimates to the network. To validate the performance of the proposed method, several driving tests under different ambient conditions are conducted using a real BEV (Kia Soul 2017), and the performance of the suggested approach is compared with a conventional model-based method. The comparison between the measured battery output power and the estimated one shows that the proposed hybrid method provides more accurate estimates than a model-based approach with over 50 % of percentage change in terms of root mean squared error. Furthermore, through a systemic network optimization, it is shown that the data from two trips (out of 14 trips) are sufficient to successfully predict the real-time battery output power, energy consumption, and the remaining driving range in different weather conditions, including winter. Therefore, the proposed NARX network is particularly suitable to circumvent the range anxiety issues and hence predict the remaining range better than the traditional vehicle dynamics-based approach.
The main goal of this study was to carry out an experimental investigation of the effectiveness and the efficiency of using carbon fiber-reinforced polymer (CFRP) strips and welded wire mesh jackets for retrofitting square and circular columns exposed to highly elevated temperatures. The investigated variables included the geometry of the column, strengthening scheme, and heating temperature. The samples were divided into three groups. The first group contains column samples not exposed to elevated temperatures and had no strengthening applied. The second category contains un-strengthened column samples subjected to elevated temperatures; the third category comprises strengthened column samples exposed to elevated temperatures. The elevated temperature exposure consisted of heating the specimens to 600 °C for 3 h. The column samples were subjected to axial compression testing till failure. The test results showed that both the circular and square columns exhibited reductions in axial capacity and initial stiffness when exposed to elevated temperatures. The use of welded wire mesh confinement around the circular and square columns exposed to elevated temperatures provided a more significant increase in strength as well as stiffness compared to strengthening the columns with unidirectional CFRP strips. In contrast, the CFRP repaired heated columns exhibited a significant increase in ductility and deformation capability without any reduction in strength than the WWM jacketed heated columns. Furthermore, the confinement effectiveness of CFRP jacketing provides considerable confinement to micro-cracked concrete compared to the WWM jacketed RC circular columns. However, in square columns the confining effectiveness for WWM was better compared to CFRP strips. Moreover, the use of CFRP strips were ineffective for recovering the stiffness of columns exposed to elevated temperatures. In addition, the results demonstrated that the use of welded wire mesh confinement and CFRP strips are cost-effective retrofitting techniques that could be used for circular and square RC columns.
This paper introduces an innovative anchor-type longitudinal fin design that copes with the sluggish phase change process in shell-and-tube ice storage units by covering the regions between the conventional fins. The influence of these fins is studied on both melting and solidification processes. The simulations show that the melting process is much slower than the solidification process (up to 201.5%), and the presence of fins can be more influential on the melting process. The examined parameters for the fins are arc angle (θ), shank length (L sh), number of anchor-type fins (N f), and number of arcs on these fins (N a). The study reveals that at an identical PCM volume, this type of fin can improve the melting time by 1367.7 and 151.8% compared to when the bare tube and conventional longitudinal fins with the same length and number are used, respectively. On the other hand, these values for the solidification process are 544.2 and 89.5%, respectively. Furthermore, it was found that these fins manage to diminish the undesirable effects of natural convection by disrupting the un-wanted thermal stratification in the container by breaking the large circulation zone for the natural fluid flow in the container into several smaller circulation areas.
Purpose To categorize, quantify and interpret findings documented in feedback letters of monitoring or auditing visits for an investigator-initiated, peer-review funded multicenter randomized trial testing probiotics for critically ill patients. Materials & methods In 37 Canadian centers, monitoring and auditing visits were performed by 3 trained individuals; findings were reported in feedback letters. At trial termination, we performed duplicate content analysis on letters, categorizing observations first into unique findings, followed by 10 pre-determined trial quality management domains. We further classified each observation into a) missing operational records, b) errors in process, and potential threats to c) data integrity, d) patient privacy or e) safety. Results Across 37 monitoring or auditing visits, 75 unique findings were categorized into 10 domains. Most frequently, observations were in domains of training documentation (180/566 [32%]) and the informed consent process (133/566 [23%]). Most observations were missing operational records (438/566 [77%]) rather than errors in process (128/566 [23%]). Of 75 findings, 13 (62/566 observations [11%]) posed a potential threat to data integrity, 1 (1/566 observation [0.18%]) to patient privacy, and 9 (49/566 observations [8.7%]) to patient safety. Conclusions Monitoring and auditing findings predominantly concerned missing documentation with minimal threats to data integrity, patient privacy or safety. Trial Registration: PROSPECT (Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial): NCT02462590.
The aim of present work is to analyze a U-type of evacuated tube solar collector in which phase change material (PCM) is employed to store surplus solar energy in daytime and reuse it at nighttime when the solar irradiation vanishes. Both charging and discharging processes are considered and modeled. Two critical points should be considered in designing the proposed collector; the stable requirement outlet temperature of the domestic solar collector during daytime (about 40°C) and assurance of a complete melting/solidification process to reach the maximum energy storage and release. Since the absorbed energy from solar radiation by heat transfer fluid and PCM in both day and nighttime strongly depends on the U-type tube's diameter, three values of which (namely, 6, 8, and 10 mm) are selected to attain the best case. The results show that the case with 6 mm diameter yields a 25% and 13.5% improvement in the liquid fraction and fluid outlet temperature, respectively, at 3:00 PM in the charging process, compared to other cases. Also, this case has achieved a 20% delay in the thermal energy release process and has increased the fluid outlet temperature by 24%, compared to other cases, at 9:00 PM in the discharging process.
The freight transportation sector accounted for 10.1% of global emissions and 16.2% of Quebec's greenhouse gas emissions in 2018. In this sector, the most salient yet little explored behavioral change opportunity is the modal shift from heavy trucks to trains. Current model developments are being made so that E4 modelers represent modal choices as endogenous variables in the models. However, if we want to continue to improve the realism of the models, it is important to know if this modeling technique is suitable for a world where radical changes are required. In this study, two types of modal shifts are implemented and compared in a TIMES-type energy model: exogenous modal shifts, with demand-side scenarios, and endogenous modal shifts, with the introduction of substitution elasticities as an endogenous behavioral feature of the model. The results of this study show that only the exogenous approach allows the modeling of disruptions: in demand, in energy consumption, and in system costs. With respect to vehicle type, the exogenous approach avoids investments in complex infrastructure (i.e., catenary), at least in the medium term, while the endogenous approach leads to results where electric trucks and catenaries appear in 2030. Only the scenario with a significant modal shift from heavy trucks to trains (Exog_max) avoids substantial energy consumption (17 PJ in 2030 and 10 PJ in 2050). The concluding recommendation is to use the exogenous approach in a disruptive modeling context. In a world where a paradigm shift is needed, the exogenous approach allows for a better representation of concepts that have been seldom modeled until now.
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9,625 members
Christophe Noll
  • Department of Medicine
Abdelatif Jaouad
  • Interdisciplinary Institute for Technological Innovation
Mario Leone
  • Faculty of Medicine and Health Sciences
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