449 research outputs found

    Dynamics of Territorial Occupation by North American Beavers in Canadian Boreal Forests: A Novel Dendroecological Approach

    Get PDF
    Research Highlights: Our study highlights a new, simple, and effective method for studying the habitat use by beavers in Canadian boreal forests. Information regarding the presence of beaver colonies and their habitat occupation is essential for proper forest management and damage prevention in the boreal forest. Background and Objectives: The North American beaver (Castor canadensis) is a major element of natural disturbance, altering the dynamics and structure of boreal forest landscapes. Beaver-related activities also affect human infrastructure, cause floods, and lead to important monetary losses for forestry industries. Our study aimed to determine the spatiotemporal patterns of beaver occupation of lodges over time. Materials and Methods: Using a dendroecological approach to date browsing activity, we studied the occupation of two lodges per water body for eight water bodies located in the boreal forest of Quebec, Canada. Results: Three sites showed alternating patterns of lodge use (occupation) over time, three sites (37.5%) demonstrated no alternating patterns of use, and two sites (25%) presented unclear patterns of lodge use. Conclusions: Alternating patterns of lodge use can be linked to food depletion and the need to regenerate vegetation around lodges, while non-alternating patterns may be related to fluctuations in water levels, the specific shrub and tree species surrounding the lodges, the size of the beaver territory, and the number of lodges present on a water body

    Role of hormone cofactors in the human papillomavirus-induced carcinogenesis of the uterine cervix

    Full text link
    peer reviewedIf human papillomavirus (HPV) is necessary for the development of (pre)neoplastic lesions of the uterine cervix, it is not sufficient. Among the cofactors involved in the malignant transformation of cells infected by HPV, sex hormones may facilitate the cervical carcinogenesis by different mechanisms, including the induction of squamous metaplasia in the transformation zone of the cervix, interactions between steroid hormones and HPV gene expression and alterations of the local immune microenvironment

    Probing punctual magnetic singularities during magnetization process in FePd films

    Get PDF
    We report the use of Lorentz microscopy to observe the domain wall structure during the magnetization process in FePd thin foils. We have focused on the magnetic structure of domain walls of bubble-shaped magnetic domains near saturation. Regions are found along the domain walls where the magnetization abruptly reverses. Multiscale magnetic simulations shown that these regions are vertical Bloch lines (VBL) and the different bubble shapes observed are then related to the inner structure of the VBLs. We were thus able to probe the presence of magnetic singularities as small as Bloch points in the inner magnetization of the domain walls

    A study protocol for a cluster randomised controlled trial on mindfulness-based stress reduction : studying effects of mindfulness-based stress reduction and an additional organisational health intervention on mental health and work-related perceptions of teachers in Dutch secondary vocational schools

    Get PDF
    Dutch teachers in secondary vocational schools suffer from stress and burnout complaints that can cause considerable problems at work. This paper presents a study design that can be used to evaluate the short-term and long-term effectiveness of mindfulness-based stress reduction (MBSR), a person-focused intervention, both within and outside of the context of an additional organisational health intervention. The proposed study comprises a cluster randomised controlled trial that will be conducted in at least three secondary vocational schools, to which teachers will be recruited from three types of courses: Care, Technology, and Economy. The allocation of the intervention programme to the participating schools will be randomised. The teachers from each school will be assigned to intervention group 1 (IG 1), intervention group 2 (IG 2), or the waiting list group (WG). IG 1 will receive MBSR training and IG 2 will receive MBSR training combined with an additional organisational health intervention. WG, that is the control group, will receive MBSR training one year later. The primary outcome variable of the proposed study is mindfulness, which will be measured using the Dutch version of the Five Facet Mindfulness Questionnaire (FFMQ-NL). In the conceptual model, the effects of teachers' mindfulness resulting from the intervention programmes (MBSR training and MBSR training combined with an additional organisational health intervention) will be related to salient (secondary outcome) variables: mental health outcomes (e.g., burnout, work engagement), work performance, work-related perceptions (job demands and job resources), and personal competencies (e.g., occupational self-efficacy). Data will be collected before (T ) and immediately after the MBSR training (T ), and 3 (T ) and 9 months (T ) after the training. The power analysis revealed a required sample size of 66 teachers (22 in each group). The proposed study aims to provide insight into (1) the short-term and long-term effects of MBSR on teachers' mental health, (2) the possible enhancing effects of the additional organisational health intervention, and (3) the teachers' experiences with the interventions (working mechanisms, steps in the mindfulness change process). Strengths of this study design are the use of both positive and negative outcomes, the wide range of outcomes, both outcome and process measures, longitudinal data, mixed methods, and an integral approach. Although the proposed study protocol may not address all weaknesses of current studies (e.g., self-selection bias, self-reporting of data, the Hawthorne effect), it is innovative in many ways and can be expected to make important contributions to both the scientific and practical debate on how to beat work-related stress and occupational burnout, and on how to enhance work engagement and work performance. Dutch Trial Register (www.trialregister.nl): NL5581. Registered on 6 July 2016

    UNDERSTANDING THE DIFFICULTIES HINDERING INTER-AGENCY COLLABORATION FOR STUDENTS WITH SPECIAL NEEDS IN QUEBEC

    Get PDF
    In 2003, the government of Quebec established the Agreement for the Complementarity of Services Between the Health and Social Services Network and the Education Network to define principles and obligations for inter- agency collaboration aimed at students with special needs and their families. This study documents the perspectives of organisation members from both networks. One hundred eighty-one participants were interviewed regarding their perceptions of inter-agency collaboration and related difficulties. Findings reveal that although network members are committed to collaborate in concordance with the Agreement, significant obstacles hinder an effective partnership, including an overall lack of coherence and gaps in the conditions required for an effective partnership, as well as insufficient awareness of the Agreement.

    Archean (3.33 Ga) microbe-sediment systems were diverse and flourished in a hydrothermal context

    Get PDF
    International audienceInteracting, diverse microbe-sediment systems exist in natural environments today but have not yet been recognized in the oldest records of life on Earth (older than 3.3 Ga) because of lack of distinctive biomarker molecules and patchy preservation of microbial paleocommunities. In an in-situ outcrop-to microbial-scale study, we have differentiated probable phototrophic, chemolithotrophic, and chemo-organotrophic fossil microbial signatures in a nearshore vol-canogenic sedimentary setting in 3.33 Ga rocks of the Josefsdal Chert, Barberton greenstone belt, South Africa, while demonstrating the importance of contemporaneous hydrothermal activity. Hydrothermal fluids, as a nutrient source, strongly controlled the development and distribution of the microbial communities and, as a silicifying agent, contributed to their rapid fossilization. We thus show that intricate microbe-sediment systems are deep-rooted in time and that at least some early life may indeed have been thermophilic. INTRODUCTION Microbial communities in natural environments exist as multispecies assemblages that interact directly with one another and with their surroundings, and thus can be viewed as distinctive systems (Nealson, 1997). For example, a wide diversity of organotrophic and lithotro-phic (chemotrophic) microorganisms has been described in present-day, carbon-rich hydrother-mally influenced basaltic sediments (Callac et al., 2013), similar to those described from early Earth. However, lack of specific biomarker preservation in very ancient rocks (Summons, 1993) and haphazard preservation of microbial communities in general (Campbell et al., 2001; Orange et al., 2009) make tracing such systems in fossilized form to the oldest records of life on Earth (early Archean, older than 3.3 Ga) very challenging. Nevertheless, phototrophic microbial communities in early to mid-Archean (ca. 3.5–3.2 Ga) strata of South Africa and Australia have been well documented (). On the other hand, no previous investigations have recognized and addressed the syngenetic diversity of Archean microbial paleocommunities—both phototrophs and che-motrophs —within their sedimentary habitats at the microbial scale and using in-situ methods. Here we describe a macroscopic to microscopic investigation of the sedimentary and geochemical settings of widespread, fossilized phototrophic and chemotrophic microorganisms in early to mid-Archean (3.33 Ga) coastal sediments from the Josefsdal Chert, Barberton greenstone belt, South Africa. We also emphasize the importance of contemporaneous hydrothermal activity both as a source of energy for biomass production and as the means of preserving the biosignatures

    Applications of Micro-Raman Spectroscopy in Cultural Heritage – Examples from the Laboratory for Conservation Research of the Collections Centre of the Swiss National Museums

    Get PDF
    The paper reports on three applications of micro-Raman spectroscopy which were carried out in the Laboratory for Conservation Research of the Collections Centre of the Swiss National Museums. The first application addresses archaeological questions about three early mediaeval fibulae which were decorated with gemstones. The determination of different corrosion products on pigeon cameras by micro-Raman spectroscopy is described in the second part of this article. The last case study discusses an example from the field of preventive conservation where changes on metal coupons from the so-called Oddy test were analysed
    corecore