Publications by authors named "GAUTHIER G"

We study experimentally at the macroscopic and microstructure scale a dense suspension of non-Brownian neutrally buoyant spherical particles experiencing periodic reversals of flow at constant rate between parallel plates and tracked individually. We first characterize the quasi-steady state reached at the end of half periods. The volume fraction of particles increases from the walls to the center as a result of migration induced by the nonuniform strain rate.

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The exact mechanisms behind population cycles remain elusive. An ongoing debate centers on whether predation by small mustelids is necessary and sufficient to generate rodent cycles, as stipulated by the specialist predator hypothesis (SPH). Specifically, the SPH predicts that the predator should respond numerically to the abundance of its prey with a delay of approximately one year, leading to delayed density-dependence in the dynamics of the prey population.

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Background: Indigenous peoples with substance use disorders (SUD) and intergenerational trauma (IGT) face complex healthcare needs. Therefore understanding Indigenous patient experiences is crucial for enhancing care delivery, fostering engagement, and achieving optimal outcomes, yet few studies explore the motivations for seeking, staying in, and utilizing treatment from an Indigenous perspective. The goal of this study was to understand the patient experience with an abstinence-based treatment model in a residential treatment setting.

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Building on previous research that demonstrates the association of youth experiences in afterschool science and higher science identities, this paper presents a network study of 421 middle school students that examines afterschool science participation, friendship ties, and science identities. Participation in afterschool science clubs is associated with higher science identity, but the mechanisms and order of causality are unclear. Youth form friendships inside and outside of school, and peers may influence participation in afterschool activities, as empirical research on friendships shows that they are associated with youth interests.

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Objective: Retrospective memory for peritraumatic reactions occurring during or immediately after trauma exposure may decrease in intensity for some over treatment. This may be due to psychotherapy-specific memory processes, such as repeated accessing of the trauma memory. Additionally, it may be that recovery drives changes in memory for these experiences.

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The present study aimed to assess the mediating role of adjustment processes in known risk factors associated with prolonged grief disorder. Data were collected in March-April 2021 through an online survey of 542 Canadian adults bereaved since March 2020. The mediating role of satisfaction with funeral rituals, bereavement support, and coping strategies on grief outcomes was tested using structural equation modeling.

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Space use by small mammals should mirror their immediate needs for food and predator shelters but can also be influenced by seasonal changes in biotic and abiotic factors. Lemmings are keystone species of the tundra food web, but information on their spatial distribution in relation to habitat heterogeneity is still scant, especially at a fine scale. In this study, we used spatially explicit capture-recapture methods to determine how topography, hydrology, vegetation, and soil characteristics influence the fine-scale spatial variations in summer density of brown lemmings ().

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Background: A train-the-trainer approach can effectively support the integration of new practice standards for health and social services professionals. This study describes the effects of an enhanced train-the-trainer program to support registered nurses and social workers working in primary care clinics in their understanding of the fundamental principles of primary care.

Methods: We implemented an enhanced train-the-trainer program for registered nurses and social workers in six primary care clinics.

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Arctic ecosystems are undergoing rapid changes, including increasing disturbance by herbivore populations, which can affect plant species coexistence and community assemblages. Although the significance of mosses in Arctic wetlands is well recognized, the long-term influence of medium-sized herbivores on the composition of moss communities has received limited attention. We used data from a long-term (25 years) Greater Snow Goose () exclusion experiment in Arctic tundra wetlands to assess changes in the composition of moss communities at multiple spatial scales (cell, 4 cm; quadrat, 100 cm; exclosure, 16 m).

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Plant biomass is a fundamental ecosystem attribute that is sensitive to rapid climatic changes occurring in the Arctic. Nevertheless, measuring plant biomass in the Arctic is logistically challenging and resource intensive. Lack of accessible field data hinders efforts to understand the amount, composition, distribution, and changes in plant biomass in these northern ecosystems.

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The rheology of particle suspensions has been extensively explored in the case of a simple shear flow, but less in other flow configurations which are also important in practice. Here we investigate the behavior of a suspension in a squeeze flow, which we revisit using local pressure measurements to deduce the effective viscosity. The flow is generated by approaching a moving disk to a fixed wall at constant velocity in the low Reynolds number limit.

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Reports of fading vole and lemming population cycles and persisting low populations in some parts of the Arctic have raised concerns about the spread of these fundamental changes to tundra food web dynamics. By compiling 24 unique time series of lemming population fluctuations across the circumpolar region, we show that virtually all populations displayed alternating periods of cyclic/non-cyclic fluctuations over the past four decades. Cyclic patterns were detected 55% of the time ( = 649 years pooled across sites) with a median periodicity of 3.

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We study experimentally the rheology of a macroscopic particle-laden soap film, designated as a "", in the simple shear configuration. Macroscopic particles are dispersed in a soap film, while being large enough that they bridge both fluid interfaces. We simultaneously perform macroscopic rheological measurements with a classical rheometer and investigate interactions at the particle scale with a camera underneath the film.

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Background And Purpose: A global decrease in brain perfusion has recently been reported during exposure to a ground-based spaceflight analog. Considering that CSF and glymphatic flow are hypothesized to be propelled by arterial pulsations, it is unknown whether a change in perfusion would impact these CSF compartments. The aim of the current study was to evaluate the relationship among changes in cerebral perfusion, ventricular volume, and perivascular space volume before, during, and after a spaceflight analog.

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The strength of indirect biotic interactions is difficult to quantify in the wild and can alter community composition. To investigate whether the presence of a prey species affects the population growth rate of another prey species, we quantified predator-mediated interaction strength using a multi-prey mechanistic model of predation and a population matrix model. Models were parametrized using behavioural, demographic and experimental data from a vertebrate community that includes the arctic fox (), a predator feeding on lemmings and eggs of various species such as sandpipers and geese.

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Rheology of macroscopic particle-laden interfaces, called "granular rafts," has been experimentally studied in the simple shear configuration. The shear-stress relation obtained from a classical rheometer exhibits the same behavior as a Bingham fluid, and the viscosity diverges with the surface fraction according to evolutions similar to 2D suspensions. The velocity field of the particles that constitute the granular raft has been measured in the stationary state.

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During the cold arctic winter, small mammals like lemmings seek refuge inside the snowpack to keep warm and they dig tunnels in the basal snow layer, usually formed of a soft depth hoar, to find vegetation on which they feed. The snowpack, however, is a heterogenous medium and lemmings should use habitats where snow properties favor their survival and winter reproduction. We determined the impact of snow physical properties on lemming habitat use and reproduction in winter by sampling their winter nests for 13 years and snow properties for 6 years across 4 different habitats (mesic, riparian, shrubland, and wetland) on Bylot Island in the Canadian High Arctic.

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Article Synopsis
  • Researchers developed a new algorithm to improve the accuracy of CEST MRI methods for tracking antiretroviral drugs (ARVs) in tissues, which previously faced limitations due to interference from biomolecules.
  • The algorithm was specifically tested on lamivudine (3TC), a common ARV, and successfully fitted its proton peaks, providing a more precise measurement of 3TC's presence in the brains of treated mice.
  • The results showed that this dual-peak fitting method correlated better with actual drug levels compared to traditional methods, indicating a significant advancement for the mapping of various ARVs using CEST MRI.
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Objective: Assessment of social processes underlying anticipation for recovery-related support from family in the event of a substance problem. We drew from literature on social support, substance use, and social networks to develop a path model connecting emotionally close family relationships, closeness among members in the wider family network (density), previous emotional support exchanges, and anticipated support.

Subjects And Methods: We used a sample from the 2019 Nebraska Annual Social Indicators Survey (284 adults; 57% female; 94% white; 46.

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Article Synopsis
  • The study investigates patients' perspectives on teleconsultation in primary care, focusing on access, benefits, disadvantages, and interprofessional collaboration.
  • Conducted through interviews with 39 patients across six clinics in Quebec, the research highlights that patients largely favor teleconsultation while emphasizing the need for personalization and involvement in decision-making.
  • Overall satisfaction with teleconsultation is high, but to optimize its implementation, patient preferences and feedback should be integral to future telehealth strategies.
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Indigenous clients in need of residential care for substance use disorders (SUD) often present with the diagnosis of substance use disorder (SUD) combined with intergenerational trauma (IGT) or both. SUD is exceedingly prevalent amongst Indigenous peoples due to the health impacts of colonisation, residential school trauma, and IGT on this population's health. We evaluated the effectiveness of a Two-Eyed Seeing approach in a four-week harm reduction residential treatment programme for clients with a history of SUD and IGT.

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Spirituality is a health protection factor recognised in the scientific literature. However, few studies have evaluated its impact on French-speaking populations, in secularised societies and even fewer in the context of a pandemic. It is therefore interesting to highlight significant relationships between spiritual quality of life and health.

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Positive spirituality has three central attributes: connectedness, meaning of life, and identity. Six factors are likely to contribute to its emergence and it can allow the development of ten positive consequences.

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Objective: Our primary objective was to evaluate how the Indigenous Healing and Seeking Safety (IHSS) model impacted residential addiction treatment program completion rates. Our secondary objective was to evaluate health service use 6 months before and 6 months after residential treatment for clients who attended the program before and after implementing IHSS.

Methods: We observed clients of the Benbowopka Residential Treatment before IHSS implementation (from April 2013 to March 31, 2016) and after IHSS implementation (from January 1, 2018 - March 31, 2020).

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Background: spp, the etiologic agents of blastomycosis, are endemic dimorphic fungi that require prolonged antifungal therapy, which can be complicated by adverse drug effects. Isavuconazonium sulphate (ISA) is a triazole with in vitro and in vivo activity against spp, but there is a paucity of clinical data supporting its use for treatment of blastomycosis.

Methods: This retrospective case series identified 14 patients with blastomycosis at least partially treated with ISA at the University of Wisconsin between 2015 and 2019.

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