4,324 research outputs found
Decay resistance variability of European wood species thermally modified by industrial process
Thermal modification is now considered as a new ecofriendly industrial wood modification process improving mainly the material decay resistance and its dimensional stability. Most industrial thermal treatment processes use convection heat transfer which induces sometimes heterogeneous treatment temperature propagation within the oven and lead to the heterogeneity in treatment efficiency. Thus, it is common that treatment is not completely effective on several stack boards, in a same batch. The aim of this paper was to study the decay resistance variability of various European wood species thermally modified. Thermal modifications were performed around 240°C during 4h, on about 10 m3 of 27 x 152 x 2000 mm3 wood planks placed in an industrial oven having a volume of 20 m3, on the following wood species: spruce, ash, beech and poplar. All of the tests concerning the decay resistance were carried out in the laboratory using untreated beech and pine woods as reference materials. An agar block test was used to determine the resistance of thermally modified woods, leached beforehand according to EN 84 standard or not, to brown-rot and white-rot fungi, according to XP CEN/TS 15083-1. A large selection of treated wood samples was tested in order to estimate the variability of treatment efficiency. Thermal treatment increased the biological durability of all leached and un-leached modified wood samples, compared with native wood species. The treatment temperature of 240°C used in this study is sufficient to reach durability classes ''durable'' or ''very durable'' for the four wood species. However, the dispersion of weight loss values, due to the fungal attacks was very important and showed a large variability of the durability of wood which has been treated in a single batch. These results showed that there is a substantial need to develop process control andÂČ indicator in order to insure that the quality of treated timber is properly evaluated with a view to putting this modified timber on the market under a chain of custody. (RĂ©sumĂ© d'auteur
Pregnant women's responses to a tailored smoking cessation intervention: turning hopelessness into competence
Background: Cognitive behavioral interventions consisting of brief counseling and the provision of self-help material designed for pregnancy have been documented as effective smoking cessation interventions for pregnant women. However, there is a need to understand how such interventions are perceived by the targeted group. Aim: To understand the cognitive, emotional, and behavioral responses of pregnant women to a clinic-based smoking cessation intervention. Methods: In-depth interviews with women attending four antenatal clinics in Cape Town, South Africa, who were exposed to a smoking intervention delivered by midwives and peer counselors. Women were purposively selected to represent a variation in smoking behavior. Thirteen women were interviewed at their first antenatal visit and 10 were followed up and reinterviewed later in their pregnancies. A content analysis approach was used, which resulted in categories and themes describing women's experiences, thoughts, and feelings about the intervention. Results: Five women quit, five had cut down, and three could not be traced for follow-up. All informants perceived the intervention positively. Four main themes captured the intervention's role in influencing women's smoking behavior. The process started with ‘understanding their reality,’ which led to ‘embracing change’ and ‘deciding to hold nothing back,’ which created a basis for ‘turning hopelessness into a feeling of competence.’Conclusion: The intervention succeeded in shifting women from feeling pessimistic about ever quitting to feeling encouraged to try and quit. Informants rated the social support they received very highly and expressed the need for the intervention to become a routine component of clinic services
Retinoic acid has different effects on UCP1 expression in mouse and human adipocytes
BACKGROUND: Increased adipose thermogenesis is being considered as a strategy aimed at preventing or reversing obesity. Thus, regulation of the uncoupling protein 1 (UCP1) gene in human adipocytes is of significant interest. Retinoic acid (RA), the carboxylic acid form of vitamin A, displays agonist activity toward several nuclear hormone receptors, including RA receptors (RARs) and peroxisome proliferator-activated receptor Ύ (PPARΎ). Moreover, RA is a potent positive regulator of UCP1 expression in mouse adipocytes. RESULTS: The effects of all-trans RA (ATRA) on UCP1 gene expression in models of mouse and human adipocyte differentiation were investigated. ATRA induced UCP1 expression in all mouse white and brown adipocytes, but inhibited or had no effect on UCP1 expression in human adipocyte cell lines and primary human white adipocytes. Experiments with various RAR agonists and a RAR antagonist in mouse cells demonstrated that the stimulatory effect of ATRA on UCP1 gene expression was indeed mediated by RARs. Consistently, a PPARΎ agonist was without effect. Moreover, the ATRA-mediated induction of UCP1 expression in mouse adipocytes was independent of PPARγ coactivator-1α. CONCLUSIONS: UCP1 expression is differently affected by ATRA in mouse and human adipocytes. ATRA induces UCP1 expression in mouse adipocytes through activation of RARs, whereas expression of UCP1 in human adipocytes is not increased by exposure to ATRA
The Status of Glaucous Gulls Larus hyperboreus in the Circumpolar Arctic
The entire world population of the Glaucous Gull Larus hyperboreus breeds in the circumpolar Arctic. Some local populations appear to be declining significanty. In this paper, we summarize the current state of knowledge on Glaucous Gull populations and trends. The total Arctic population is estimated at approximately 171 000 breeding pairs (> 342 000 breeding individuals) distributed among at least 2700 colonies (many not documented). Population declines may be attributable to egg harvest, contaminants, or food shortages, but other factors operating outside the breeding season should not be excluded. We recommend collaborative conservation efforts that will include better population estimates in most countries, as well as standardized monitoring programs.Toute la population mondiale de goĂ©lands bourgmestres Larus hyperboreus se reproduit dans lâArctique circumpolaire. Certaines populations locales semblent diminuer considĂ©rablement. Dans cette communication, nous rĂ©sumons lâĂ©tat actuel des connaissances sur les populations et les tendances concernant le goĂ©land bourgmestre. La population arctique totale est estimĂ©e Ă environ 171 000 couples reproducteurs (> 342 000 individus reproducteurs) rĂ©partis dans au moins 2 700 colonies (dont grand nombre nâont pas Ă©tĂ© consignĂ©es). Les dĂ©clins de population peuvent ĂȘtre attribuables Ă la rĂ©colte des Ćufs, aux contaminants ou aux pĂ©nuries de nourriture, bien quâil ne faille pas exclure dâautres facteurs ne se rapportant pas Ă la saison de reproduction. Nous recommandons des efforts de conservation communs qui comprendront de meilleures estimations de population dans la plupart des pays de mĂȘme que des programmes de surveillance normalisĂ©s
Neuropsychiatric symptoms and the outcome of cognitive trajectories in older adults free of dementia: The Mayo Clinic Study of Aging
Objective
Neuropsychiatric symptoms (NPS) are associated with the risk of incident mild cognitive impairment (MCI) and dementia. We examined associations between NPS and the outcomes of global and domainâspecific cognitive trajectories.
Methods
In this longitudinal study conducted in the setting of the populationâbased Mayo Clinic Study of Aging, 5081 communityâdwelling, nondemented individuals aged â„50 years (51% males) underwent NPS assessment using Neuropsychiatric Inventory Questionnaire (NPIâQ), and Beck Depression and Anxiety Inventories (BDIâII, BAI). Global and domainâspecific (memory, language, attention, and visuospatial skills) cognitive performance was assessed through neuropsychological testing every 15 months. Associations between baseline NPS and trajectories for individual yearly change in cognitive zâscores were calculated using linear mixedâeffect models.
Results
Cognition declined regardless of NPS status over the median followâup of 4.5 years. Presence of NPS was associated with increased cognitive decline. Differences in annualized change in global cognition zâscores for participants with NPS compared to without NPS ranged from â0.018 (95% CI â0.032, â0.004; p = 0.011) for irritability to â0.159 (â0.254, â0.065; p = 0.001) for hallucinations. Associations between NPS and annual decline in global cognition were significant for most NPIâQâassessed NPS and clinical depression (BDIâIIâ„13). Participants with NPIâQâassessed depression, apathy, nighttime behavior, and clinical depression had greater decline in all domainâspecific zâscores; presence of delusions and anxiety was associated with more pronounced decline in language, attention and visuospatial skills.
Conclusion
NPS were associated with a more accelerated cognitive decline. Clinical assessment and potential treatment of NPS is warranted even in a community setting as NPS may impact cognitive decline in nondemented individuals
A 250 plastome phylogeny of the grass family (Poaceae): topological support under different data partitions
The systematics of grasses has advanced through applications of plastome phylogenomics, although studies have been largely limited to subfamilies or other subgroups of Poaceae. Here we present a plastome phylogenomic analysis of 250 complete plastomes (179 genera) sampled from 44 of the 52 tribes of Poaceae. Plastome sequences were determined from high throughput sequencing libraries and the assemblies represent over 28.7 Mbases of sequence data. Phylogenetic signal was characterized in 14 partitions, including (1) complete plastomes; (2) protein coding regions; (3) noncoding regions; and (4) three loci commonly used in single and multi-gene studies of grasses. Each of the four main partitions was further refined, alternatively including or excluding positively selected codons and also the gaps introduced by the alignment. All 76 protein coding plastome loci were found to be predominantly under purifying selection, but specific codons were found to be under positive selection in 65 loci. The loci that have been widely used in multi-gene phylogenetic studies had among the highest proportions of positively selected codons, suggesting caution in the interpretation of these earlier results. Plastome phylogenomic analyses confirmed the backbone topology for Poaceae with maximum bootstrap support (BP). Among the 14 analyses, 82 clades out of 309 resolved were maximally supported in all trees. Analyses of newly sequenced plastomes were in agreement with current classifications. Five of seven partitions in which alignment gaps were removed retrieved Panicoideae as sister to the remaining PACMAD subfamilies. Alternative topologies were recovered in trees from partitions that included alignment gaps. This suggests that ambiguities in aligning these uncertain regions might introduce a false signal. Resolution of these and other critical branch points in the phylogeny of Poaceae will help to better understand the selective forces that drove the radiation of the BOP and PACMAD clades comprising more than 99.9% of grass diversity
Results from the 5-year SQ grass sublingual immunotherapy tablet asthma prevention (GAP) trial in children with grass pollen allergy
Signals from the brain and olfactory epithelium control shaping of the mammalian nasal capsule cartilage
Facial shape is the basis for facial recognition and categorization. Facial features reflect the underlying geometry of the skeletal structures. Here, we reveal that cartilaginous nasal capsule (corresponding to upper jaw and face) is shaped by signals generated by neural structures: brain and olfactory epithelium. Brain-derived Sonic Hedgehog (SHH) enables the induction of nasal septum and posterior nasal capsule, whereas the formation of a capsule roof is controlled by signals from the olfactory epithelium. Unexpectedly, the cartilage of the nasal capsule turned out to be important for shaping membranous facial bones during development. This suggests that conserved neurosensory structures could benefit from protection and have evolved signals inducing cranial cartilages encasing them. Experiments with mutant mice revealed that the genomic regulatory regions controlling production of SHH in the nervous system contribute to facial cartilage morphogenesis, which might be a mechanism responsible for the adaptive evolution of animal faces and snouts
Self-reported restless legs syndrome and involuntary leg movements during sleep are associated with symptoms of attention deficit hyperactivity disorder
Lack of physical activity, neuropsychiatric symptoms and the risk of incident mild cognitive impairment in older community-dwelling individuals â AÂ prospective cohort study
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