Key Beliefs for Targeted Interventions to Increase Physical Activity in Children: Analyzing Data from an Extended Version of the Theory of Planned Behaviour

Given the high prevalence of overweight and low levels of physical activity among children, a better understanding of physical activity behaviour is an important step in intervention planning. This study, based on the theory of planned behaviour, was conducted among 313 fifth graders and their parents. Children completed a computer-based questionnaire to evaluate theoretical constructs and behaviour. Additional information was obtained from parents by means of a questionnaire. Correlates of children's physical activity were intention and self-identity. Determinants of intention were self-efficacy, self-identity, and attitude. Parental variables were mediated through cognitions. Among girls, practicing sedentary activities was an additional negative determinant of intention. Key beliefs of boys and girls were related to time management and difficulties associated with physical activity. For girls, social identification as an active girl was another important belief related to positive intention. This study provides theory-based information for the development of more effective interventions aimed at promoting physical activity among children

Impacts des barrages sur les débits annuels minimums en fonction des régimes hydrologiques artificialisés au Québec (Canada)

Les débits annuels minimums des rivières déterminent le volume d’habitat minimum disponible pour assurer la survie des espèces aquatiques en période d’étiage. Dans cette étude, nous comparons les impacts de barrages sur les caractéristiques (période d’occurrence, magnitude, amplitude de variation et asymétrie) de ces débits dans trois régimes hydrologiques artificialisés d’une part, et les débits annuels minimums mesurés en aval des barrages aux normes de débits réservés pour protéger les habitats du poisson au Québec, d’autre part. Nous avons analysé 72 stations appartenant aux régimes artificialisés d’Inversion (26 stations), d’Homogénéisation (18 stations) et de Type Naturel (28 stations). Toutes ces stations appartiennent au bassin versant du fleuve Saint-Laurent. La présente analyse est fondée sur la comparaison des débits mesurés en rivières naturelles (75 stations) à ceux mesurés en aval des barrages au moyen des méthodes de proportionnalité et graphique. Il ressort de ces comparaisons les principaux résultats suivants.En régime artificialisé d’Inversion caractérisé par les débits mensuels maximums en hiver et les débits mensuels minimums au printemps, les impacts des barrages se traduisent par une hausse significative de fréquence des débits annuels minimums au printemps au moment de la fonte des neiges mais une baisse en été, une diminution significative de la magnitude des débits pour les bassins versants de taille 10 000 km2.Annual minimum discharges represent a crucial hydrologic parameter for the health of aquatic ecosystems. They determine the volume of available habitat for aquatic species and influence the concentration of pollutant within the fluvial system during low flows. They are also of importance for instream infrastructures and for the regulation of fluvial transport. For these reasons, the minimum discharges constitute the main hydrologic parameters for which clear regulation have been defined in several countries. In the province of Québec, albeit the large amount of dams on several important fluvial systems, there seems to exist a lack of studies examining their effects on the annual minimum discharges. This paper is aiming at highlighting the effects of dams (1) by examining their effect on the characteristics of annual minimum discharges for artificialised flow regimes in Québec, and (2) by comparing those discharges with recommended instream flows to protect fish habitats.Firstly, the effect of dams on annual minimum discharges is examined for the three types of artificialised flow regimes found in Québec. From the analysis of seasonal and monthly discharges, ASSANI et al. (2004) documented the three types of artificialised hydrologic regime downstream from dams: the inversion, the homogenization, and the natural type flow regimes. The inversion flow regime presents high monthly discharge values in winter and low monthly discharge values during spring. This type of regime occurs solely on the north shore of the St-Lawrence River and pertains to rivers with large reservoirs feeding in hydropower stations. The homogenization flow regime presents small annual fluctuations of the monthly discharge. The maximum monthly discharges are recorded during spring where- as the minimum monthly discharges frequently occur during fall. This type of regime is often associated with reservoirs created on large streams for which the storage of spring water is less important. This regime is observed mainly on the north shore of the St-Lawrence river. In the natural type flow regime, the maximum monthly discharges take place during spring snowmelt while minimum monthly discharges occur either during summer or winter. The annual natural flow characteristics are thus conserved albeit the existence of the dam. This regime pertains to dams with small reservoirs and it is found on both side of the St-Lawrence River.Secondly, annual mimimum discharges are compared with minimum instream flows recommended by BELZILE et al. (1997). These ones defined the minimum instream flows based on the different species of fish and their life cycle. Downstream from dams, the instream flows (Qr) can be estimated using the following relation:Qr = ek.Sawhere S represents the drainage area upstream from the dam; a and k are respectively regional and seasonal parameters. These parameters are associated to the ecohydrological region, to the season as well as to the critical phases of life cycle for the fish species found within the ecohydrological regions.From the Historical Stream Flow Summary of Environmental Canada, the distribution of discharge from 107 stations were selected and analysed. From those, 72 were located on rivers with dams and 75 on rivers with no regulation. On regulated rivers, 26, 18 and 28 were identified as belonging to the inversed, homogeneous and natural type regimes, respectively. All stations were located in the St-Lawrence drainage area. To highlight the effect of dams, we performed a comparison between the annual minimum discharges for stations on artificialised rivers to those from stations belonging to rivers with no regulation. The comparison is performed according to the size of the drainage basins (proportionality method) and uses a set of parametric and non-parametric statistical tests depending on the type of data. The proportionality method was chosen because of the non-availability of the discharges for the pre-dam periods. According to RICHTER et al. (1996), river flows can be described using several parameters relating to the daily discharges: the magnitude, the frequency, the duration, the timing and the rate of change (amplitude of the variability). The daily discharges required to compute these parameters were not available. The date of occurrence of annual minimum discharges, their magnitude, the interannual variability of the magnitude and the skewness of the distribution could however be obtained from the Historical Stream Flow Summary of Environmental Canada.The analysis of annual minimum discharges for the three types of artificialised flow regimes highlights several key elements associated with the effect of dams. For the inversion flow regime, the presence of dams increases and decreases significantly the occurrence of annual minimum discharges during spring and summer, respectively. For drainage area smaller than 10 000 km2, the magnitude of the annual minimum discharge is decreased significantly. Finally, the between-year variability is increased and the distribution presents a strong skewness. For the natural type flow regime, an increase in annual minimum discharges during the period between November and January can be observed as well as a significant decrease in magnitude for the small fluvial systems (drainage area 10 000 km2

Phylogenetic Implications of a Unique 5.8S nrDNA Insertion in Cyperaceae

The purpose of this study was to assess the phylogenetic utility of a large insertion (3 bp) in the 5.8S gene of nuclear ribosomal DNA (nrDNA) in Cyperaceae and selected Juncaceae. This was done by reconstructing the character evolution of the insertion on a phylogeny derived from rbcL sequences. Results suggest that the insertion was gained once at the base of Cyperaceae followed by multiple losses in its most-derived taxa. Despite several homoplastic losses (CI = 0.20), the pattern of insertion loss (RI = 0.88), and base pair variation within the insertion were useful for defining sedge clades at various taxonomic levels. For example, whereas a loss of the insertion appeared to characterize a major terminal clade within Cyperaceae, both an insertion loss and sequence variation were consistent with infrageneric clades previously discovered in an ITS phylogeny of Eleocharis. The presence/absence of the insertion also supported previous conclusions based on morphological and molecular data that tribe Scirpeae and Scirpus s.l. are polyphyletic. In the context of our current understanding of Cyperaceae relationships, evolutionary patterns related to this insertion provide additional support for groups defined in prior phylogenetic analyses. The present analysis also suggests that the controversial position of Oxychloe andina (Juncaceae) in previous rbcL analyses, as sister to Cyperaceae (Y12978) or as nested within Cyperaceae (U49222), is due to the fact that Y12978 is a Juncaceae/Cyperaceae chimera, whereas U49222 is the sequence of a Cyperaceae contaminant. When U49222 is excluded from analyses and the Cyperaceae portion of Y12978 is removed, Juncaceae and Cyperaceae are monophyletic with Oxychloe positioned within a Juncaceae clade of single-flowered genera

Hamiltonians separable in cartesian coordinates and third-order integrals of motion

We present in this article all Hamiltonian systems in E(2) that are separable in cartesian coordinates and that admit a third-order integral, both in quantum and in classical mechanics. Many of these superintegrable systems are new, and it is seen that there exists a relation between quantum superintegrable potentials, invariant solutions of the Korteweg-De Vries equation and the Painlev\'e transcendents.Comment: 19 pages, Will be published in J. Math. Phy

Singularity confinement and algebraic integrability

Two important notions of integrability for discrete mappings are algebraic integrability and singularity confinement, have been used for discrete mappings. Algebraic integrability is related to the existence of sufficiently many conserved quantities whereas singularity confinement is associated with the local analysis of singularities. In this paper, the relationship between these two notions is explored for birational autonomous mappings. Two types of results are obtained: first, algebraically integrable mappings are shown to have the singularity confinement property. Second, a proof of the non-existence of algebraic conserved quantities of discrete systems based on the lack of confinement property is given.Comment: 18 pages, no figur

A common framework for identifying linkage rules across different types of interactions

Species interactions, ranging from antagonisms to mutualisms, form the architecture of biodiversity and determine ecosystem functioning. Understanding the rules responsible for who interacts with whom, as well as the functional consequences of these interspecific interactions, is central to predict community dynamics and stability. Species traits sensu lato may affect different ecological processes by determining species interactions through a two-step process. First, ecological and life-history traits govern species distributions and abundance, and hence determine species co-occurrence and the potential for species to interact. Secondly, morphological or physiological traits between co-occurring potential interaction partners should match for the realization of an interaction. Here, we review recent advances on predicting interactions from species co-occurrence and develop a probabilistic model for inferring trait matching. The models proposed here integrate both neutral and trait-matching constraints, while using only information about known interactions, thereby overcoming problems originating from undersampling of rare interactions (i.e. missing links). They can easily accommodate qualitative or quantitative data and can incorporate trait variation within species, such as values that vary along developmental stages or environmental gradients. We use three case studies to show that the proposed models can detect strong trait matching (e.g. predator‿prey system), relaxed trait matching (e.g. herbivore‿plant system) and barrier trait matching (e.g. plant‿pollinator systems). Only by elucidating which species traits are important in each process (i.e. in determining interaction establishment and frequency), we can advance in explaining how species interact and the consequences of these interactions for ecosystem functioning. A lay summary is available for this articlePeer Reviewe

Chromatin Profiles of Chromosomally Integrated Human Herpesvirus-6A

Human herpesvirus-6A (HHV-6A) and 6B (HHV-6B) are two closely related betaherpesviruses that are associated with various diseases including seizures and encephalitis. The HHV-6A/B genomes have been shown to be present in an integrated state in the telomeres of latently infected cells. In addition, integration of HHV-6A/B in germ cells has resulted in individuals harboring this inherited chromosomally integrated HHV-6A/B (iciHHV-6) in every cell of their body. Until now, the viral transcriptome and the epigenetic modifications that contribute to the silencing of the integrated virus genome remain elusive. In the current study, we used a patient-derived iciHHV-6A cell line to assess the global viral gene expression profile by RNA-seq, and the chromatin profiles by MNase-seq and ChIP-seq analyses. In addition, we investigated an in vitro generated cell line (293-HHV-6A) that expresses GFP upon the addition of agents commonly used to induce herpesvirus reactivation such as TPA. No viral gene expression including miRNAs was detected from the HHV-6A genomes, indicating that the integrated virus is transcriptionally silent. Intriguingly, upon stimulation of the 293-HHV-6A cell line with TPA, only foreign promoters in the virus genome were activated, while all HHV-6A promoters remained completely silenced. The transcriptional silencing of latent HHV-6A was further supported by MNase-seq results, which demonstrate that the latent viral genome resides in a highly condensed nucleosome-associated state. We further explored the enrichment profiles of histone modifications via ChIP-seq analysis. Our results indicated that the HHV-6 genome is modestly enriched with the repressive histone marks H3K9me3/H3K27me3 and does not possess the active histone modifications H3K27ac/H3K4me3. Overall, these results indicate that HHV-6 genomes reside in a condensed chromatin state, providing insight into the epigenetic mechanisms associated with the silencing of the integrated HHV-6A genome

Characterisation of the Upper Respiratory Tract Virome of Feedlot Cattle and its Association with Bovine Respiratory Disease

Bovine respiratory disease (BRD) is a major health problem within the global cattle industry. This disease has a complex aetiology, with viruses playing an integral role. In this study, metagenomics was used to sequence viral nucleic acids in the nasal swabs of BRD affected cattle. Viruses detected included those well known for their association with BRD in Australia (bovine viral diarrhea virus 1), as well as viruses known to be present but not fully characterised (bovine coronavirus) and viruses that have not been reported in BRD affect cattle in Australia (bovine rhinitis, bovine influenza D, and bovine nidovirus). Nasal swabs from a case control study were subsequently tested for 10 viruses and the presence of at least one virus was found to be significantly associated with BRD. Some of the more recently detected viruses had inconsistent association with BRD. Full genome sequences for bovine coronavirus, a virus increasingly associated with BRD, and bovine nidovirus were complete. Both viruses belong to the Coronaviridae family, which are frequently associated with disease in mammals. This study has provided greater insights into the viral pathogens associated with BRD and highlighted the need for further studies to elucidate more precisely the roles viruses play in BRD

Characterisation of the Upper Respiratory Tract Virome of Feedlot Cattle and its Association with Bovine Respiratory Disease

Bovine respiratory disease (BRD) is a major health problem within the global cattle industry. This disease has a complex aetiology, with viruses playing an integral role. In this study, metagenomics was used to sequence viral nucleic acids in the nasal swabs of BRD affected cattle. Viruses detected included those well known for their association with BRD in Australia (bovine viral diarrhea virus 1), as well as viruses known to be present but not fully characterised (bovine coronavirus) and viruses that have not been reported in BRD affect cattle in Australia (bovine rhinitis, bovine influenza D, and bovine nidovirus). Nasal swabs from a case control study were subsequently tested for 10 viruses and the presence of at least one virus was found to be significantly associated with BRD. Some of the more recently detected viruses had inconsistent association with BRD. Full genome sequences for bovine coronavirus, a virus increasingly associated with BRD, and bovine nidovirus were complete. Both viruses belong to the Coronaviridae family, which are frequently associated with disease in mammals. This study has provided greater insights into the viral pathogens associated with BRD and highlighted the need for further studies to elucidate more precisely the roles viruses play in BRD