1,636 research outputs found

    Triggering rogue waves in opposing currents

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    We show that rogue waves can be triggered naturally when a stable wave train enters a region of an opposing current flow. We demonstrate that the maximum amplitude of the rogue wave depends on the ratio between the current velocity, U0 U_0 , and the wave group velocity, cg c_g . We also reveal that an opposing current can force the development of rogue waves in random wave fields, resulting in a substantial change of the statistical properties of the surface elevation. The present results can be directly adopted in any field of physics in which the focusing Nonlinear Schrodinger equation with non constant coefficient is applicable. In particular, nonlinear optics laboratory experiments are natural candidates for verifying experimentally our results.Comment: 5 pages, 5 figure

    Motor deficits in schizophrenia quantified by nonlinear analysis of postural sway.

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    Motor dysfunction is a consistently reported but understudied aspect of schizophrenia. Postural sway area was examined in individuals with schizophrenia under four conditions with different amounts of visual and proprioceptive feedback: eyes open or closed and feet together or shoulder width apart. The nonlinear complexity of postural sway was assessed by detrended fluctuation analysis (DFA). The schizophrenia group (n = 27) exhibited greater sway area compared to controls (n = 37). Participants with schizophrenia showed increased sway area following the removal of visual input, while this pattern was absent in controls. Examination of DFA revealed decreased complexity of postural sway and abnormal changes in complexity upon removal of visual input in individuals with schizophrenia. Additionally, less complex postural sway was associated with increased symptom severity in participants with schizophrenia. Given the critical involvement of the cerebellum and related circuits in postural stability and sensorimotor integration, these results are consistent with growing evidence of motor, cerebellar, and sensory integration dysfunction in the disorder, and with theoretical models that implicate cerebellar deficits and more general disconnection of function in schizophrenia

    Exploring the use of new school buildings through post-occupancy evaluation and participatory action research

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    This paper presents the results of the development and testing of an integrated post-occupancy evaluation (POE) approach for teachers, staff, pupils and community members using newly constructed school buildings. It focusses on three cases of UK secondary schools, demonstrating how users can be inspired to engage with the problems of school design and energy use awareness. The cases provided new insights into the engagement of school teachers, staff and young people regarding issues of sustainability, management, functional performance and comfort. The integrative approach adopted in these cases provided a more holistic understanding of these buildings’ performance than could have been achieved by either observational or more traditional questionnaire-based methods. Moreover, the whole-school approach, involving children in POE, provided researchers with highly contextualised information about how a school is used, how to improve the quality of school experiences (both socially and educationally) and how the school community is contributing to the building's energy performance. These POE methods also provided unique opportunities for children to examine the social and cultural factors impeding the adoption of energy-conscious and sustainable behaviours

    Diversity and Keratin Degrading Ability of Fungi Isolated from Canadian Arctic Marine Bird Feathers

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    We present the first records of fungi associated with feathers from seabirds and sea ducks in the Canadian Arctic and sub-Arctic. Birds sampled in Nunavut and Newfoundland (Canada) included the Common Eider (Somateria mollissima), King Eider (S. spectabilis), Black-legged Kittiwake (Rissa tridactyla), Northern Fulmar (Fulmarus glacialis), Glaucous Gull (Larus hyperboreus), Black Guillemot (Cepphus grylle), and Thick-billed Murre (Uria lomvia). In total 19 fungal species were cultured from feathers, identified using ITS rDNA barcoding, and screened for their ability to degrade keratin using a keratin azure assay. Our results indicate that 1) of the 19 isolates, 74% were ascomycetes, while the remaining 26% were basidiomycetes (yeasts); 2) 21% of the ascomycete isolates demonstrated keratinolytic activity (a known pathogenicity factor for fungi that may potentially be harmful to birds); 3) the largest number of fungi were cultured from the sampled Thick-billed Murre; and 4) based on a multiple correspondence analysis, there is some indication that both the King Eider and the Thick-billed Murre collected in the low Arctic had distinct fungal communities that were different from each other and from the other birds sampled. Although our sample sizes were small, initial trends in point (4) do demonstrate that additional study is merited to assess whether the fungal community differences are influenced by variation in the known ecologies of the avian hosts and fungi identified.Nous prĂ©sentons les premiers enregistrements de champignons se rapportant aux plumes d’oiseaux et de canards de mer dans l’Arctique et la rĂ©gion subarctique du Canada. Parmi les oiseaux Ă©chantillonnĂ©s au Nunavut et Ă  Terre-Neuve (Canada), notons l’eider Ă  duvet (Somateria mollissima), l’eider Ă  tĂȘte grise (S. spectabilis), la mouette tridactyle (Rissa tridactyla), le fulmar borĂ©al (Fulmarus glacialis), le goĂ©land bourgmestre (Larus hyperboreus), le guillemot Ă  miroir (Cepphus grylle) et le guillemot de BrĂŒnnich (Uria lomvia). En tout, 19 espĂšces de champignons ont Ă©tĂ© prĂ©levĂ©es Ă  partir de plumes. Elles ont Ă©tĂ© identifiĂ©es au moyen de codes Ă  barres ITS ADNr et examinĂ©es afin de dĂ©terminer si elles sont capables de dĂ©grader la kĂ©ratine, et ce, Ă  l’aide d’une Ă©preuve de dĂ©gradation de la kĂ©ratine au bleu azur. Nos rĂ©sultats indiquent : 1) que parmi les 19 isolats, 74 % Ă©taient des ascomycĂštes et que les 26 % restants Ă©taient des basidiomycĂštes (levures); 2) que 21 % des isolats d’ascomycĂštes ont affichĂ© une activitĂ© kĂ©ratinolytique (un facteur de pathogĂ©nicitĂ© pour les champignons, facteur susceptible de nuire aux oiseaux); 3) que le plus grand nombre de cultures de champignons a Ă©tĂ© prĂ©levĂ© chez le guillemot de BrĂŒnnich; et 4) que d’aprĂšs une analyse de correspondance multiple, il y a une certaine indication que les Ă©chantillons de l’eider Ă  tĂȘte grise et du guillemot de BrĂŒnnich recueillis dans le Bas-Arctique comprenaient des communautĂ©s fongiques distinctes qui diffĂ©raient les unes des autres ainsi que des autres oiseaux Ă©chantillonnĂ©s. MĂȘme si la taille de nos Ă©chantillons Ă©tait petite, les premiĂšres tendances ressortant du point (4) dĂ©montrent qu’il y a lieu de faire des Ă©tudes plus poussĂ©es afin de dĂ©terminer si les diffĂ©rences entre les communautĂ©s fongiques sont influencĂ©es par la variation des Ă©cologies connues des hĂŽtes aviaires et des champignons identifiĂ©s

    Miniaturized data loggers and computer programming improve seabird risk and damage assessments for marine oil spills in Atlantic Canada

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    Obtaining useful information on marine birds that can aid in oil spill (and other hydrocarbon release) risk and damage assessments in offshore environments is challenging. Technological innovations in miniaturization have allowed archival data loggers to be deployed successfully on marine birds vulnerable to hydrocarbons on water. A number of species, including murres (both Common, Uria aalge, and Thick-billed, U. lomvia) have been tracked using geolocation devices in eastern Canada, increasing our knowledge of the seasonality and colony-specific nature of their susceptibility to oil on water in offshore hydrocarbon production areas and major shipping lanes. Archival data tags are starting to resolve questions around behaviour of vulnerable seabirds at small spatial scales relevant to oil spill impact modelling, specifically to determine the duration and frequency at which birds fly at sea. Advances in data capture methods using voice activated software have eased the burden on seabird observers who are collecting increasingly more detailed information on seabirds during ship-board and aerial transects. Computer programs that integrate seabird density and bird behaviour have been constructed, all with a goal of creating more credible seabird oil spill risk and damage assessments. In this paper, we discuss how each of these technological and computing innovations can help define critical inputs into seabird risk and damage assessments, and when combined, can provide a more realistic understanding of the impacts to seabirds from any hydrocarbon release

    Survey of Community Pharmacy Customers’ Medication Storage and Disposal Methods

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    Many people store medications in bathrooms, which provide a moist, humid environment that speeds up the breakdown process of medications. The proper way to store medicines is in a cool, dry place out of the reach of children. Every year medications are also disposed of improperly presenting a risk to both humans and the environment. About one-third of all sold medications are unused. The most common ways patients dispose of medications in the United States are flushing down the toilet or sink, and throwing them away. Because of this pharmaceuticals have been found in groundwater, and drinking water proving hazardous to both humans and ecosystems. In Congress today, both the Drug Free Water Act and the Safe Drug Disposal Act have been proposed to limit the disposal of pharmaceuticals in sewage systems, and provide the means of controlled substance disposal through take-back programs. In February 2007 the White House Office of National Drug Control Policy (ONDCP) established guidelines for the disposal of prescription medications. ONDCP guidelines are: take unused, unneeded or expired medications out of the original container, mix with an undesirable substance (such as coffee grounds), securely seal in impermeable containers, such as sealable bags, and throw into the trash. ONDCP recommends only flushing if the label or patient information specifies to do so. Taking advantage of community pharmaceutical take-back programs is highly encouraged

    Pervasive and dynamic protein binding sites of the mRNA transcriptome in Saccharomyces cerevisiae

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    Abstract Background Protein-RNA interactions are integral components of nearly every aspect of biology, including regulation of gene expression, assembly of cellular architectures, and pathogenesis of human diseases. However, studies in the past few decades have only uncovered a small fraction of the vast landscape of the protein-RNA interactome in any organism, and even less is known about the dynamics of protein-RNA interactions under changing developmental and environmental conditions. Results Here, we describe the gPAR-CLIP (global photoactivatable-ribonucleoside-enhanced crosslinking and immunopurification) approach for capturing regions of the untranslated, polyadenylated transcriptome bound by RNA-binding proteins (RBPs) in budding yeast. We report over 13,000 RBP crosslinking sites in untranslated regions (UTRs) covering 72% of protein-coding transcripts encoded in the genome, confirming 3' UTRs as major sites for RBP interaction. Comparative genomic analyses reveal that RBP crosslinking sites are highly conserved, and RNA folding predictions indicate that secondary structural elements are constrained by protein binding and may serve as generalizable modes of RNA recognition. Finally, 38% of 3' UTR crosslinking sites show changes in RBP occupancy upon glucose or nitrogen deprivation, with major impacts on metabolic pathways as well as mitochondrial and ribosomal gene expression. Conclusions Our study offers an unprecedented view of the pervasiveness and dynamics of protein-RNA interactions in vivo.http://deepblue.lib.umich.edu/bitstream/2027.42/112318/1/13059_2012_Article_3050.pd

    Genetic analysis of seed traits in \u3ci\u3eSorghum bicolor\u3c/i\u3e that affect the human gut microbiome

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    Prebiotic fibers, polyphenols and other molecular components of food crops significantly affect the composition and function of the human gut microbiome and human health. The abundance of these, frequently uncharacterized, microbiome-active components vary within individual crop species. Here, we employ high throughput in vitro fermentations of pre-digested grain using a human microbiome to identify segregating genetic loci in a food crop, sorghum, that alter the composition and function of human gut microbes. Evaluating grain produced by 294 sorghum recombinant inbreds identifies 10 loci in the sorghum genome associated with variation in the abundance of microbial taxa and/or microbial metabolites. Two loci co-localize with sorghum genes regulating the biosynthesis of condensed tannins. We validate that condensed tannins stimulate the growth of microbes associated with these two loci. Our work illustrates the potential for genetic analysis to systematically discover and characterize molecular components of food crops that influence the human gut microbiome

    Fecal Short-Chain Fatty Acid Concentrations Increase in Newly Paired Male Marmosets (Callithrix jacchus)

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    The role by which the gut microbiome influences host health (e.g., energy equilibrium and immune system) may be partly mediated by short-chain fatty acids, which are bacterial fermentation products from the dietary fibers. However, little is known about longitudinal changes in gut microbiome metabolites during cohabitation alongside social contact. In common marmosets (Callithrix jacchus), the gut microbiome community is influenced by social contact, as newly paired males and females develop convergent microbial profiles. Here, we monitored the dynamics of short-chain fatty acid concentrations in common marmoset feces from the prepairing (PRE) to postpairing (POST) stages. In males, we observed that the con- centrations of acetate, propionate, isobutyrate, and isovalerate significantly increased in the POST stage compared to the PRE stage. However, no significant changes were found in females. We further found that the propionate concentration was significantly positively correlated with the abundance of Phascolarctobacterium in the male feces. Thus, the sex difference in the changes in the concentrations of short-chain fatty acids might be related to sex-biased gut microbiome transmission after pairing. We suggest that the significant changes in the gut microbiomes and some short-chain fatty acids of the common marmoset during cohabitation may contribute to physiological homeostasis during pairing
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