3,427 research outputs found

    Flooding and Inundation Modeling in the Great Bay Estuary

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    As part of this research, FVCOM, a finite-volume coastal ocean numerical hydrodynamic model (Chen, et al., 2003), was implemented into the Great Bay estuary. FVCOM is one of several community models that have been developed for coastal regions, and was selected because it utilizes an unstructured grid to discretize the model domain. The unstructured grid provides the ability to have fine scale resolution near the boundary or coastline and decreased resolution away from the boundary where the flow field is less complicated, resulting in greatly reduced computational expense in less dynamic regions allowing model runs to be completed in much shorter time periods. Grid development also requires that bathymetric data is accurately assigned to grid nodes in such a way that the model itself will be numerically stable. This requires significant development time implementing an appropriate grid mesh (Persson and Strang, 2004) with bathymetry data that has been smoothed to limit inherent numerical noise in the computations. FVCOM was implemented on a grid with finest resolution equaling 30 m, and then tested on a 10 day run with offshore forcing determined analytically by the 8 most energetic semi-diurnal (M2, N2, S2, K2) and diurnal (K1, O1, P1, Q1) tidal constituents at Fort Pt., NH (https://tidesandcurrents.noaa.gov/harcon.html?id=8423898), and including fresh water river fluxes from 6 rivers equivalent to 5 times the average daily discharge (Ward and Bub, 2007). The model was further tested utilizing the 100 year tropical storm event estimated from the North Atlantic Coast Comprehensive Study (NACCS; USACE, 2015), and the highest projected sea level rise scenario for year 2100 estimated by NOAA (http://www.corpsclimate.us/ccaceslcurves.cfm). The numerically stable model indicates that the grid can be used to simulate tidal forcing with maximum projected year storm surge and sea level rise in the Great Bay, and – with further development to include finer (10 m) mesh resolution and inclusion of surface waves and wind forcing – may be able to predict future flooding scenarios based on forecasted storm events and sea level rise

    Inbreeding ratio and genetic relationships among strains of the Western clawed frog, Xenopus tropicalis

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    The Western clawed frog, Xenopus tropicalis, is a highly promising model amphibian, especially in developmental and physiological research, and as a tool for understanding disease. It was originally found in the West African rainforest belt, and was introduced to the research community in the 1990s. The major strains thus far known include the Nigerian and Ivory Coast strains. However, due to its short history as an experimental animal, the genetic relationship among the various strains has not yet been clarified, and establishment of inbred strains has not yet been achieved. Since 2003 the Institute for Amphibian Biology (IAB), Hiroshima University has maintained stocks of multiple X. tropicalis strains and conducted consecutive breeding as part of the National BioResource Project. In the present study we investigated the inbreeding ratio and genetic relationship of four inbred strains at IAB, as well as stocks from other institutions, using highly polymorphic microsatellite markers and mitochondrial haplotypes. Our results show successive reduction of heterozygosity in the genome of the IAB inbred strains. The Ivory Coast strains clearly differed from the Nigerian strains genetically, and three subgroups were identified within both the Nigerian and Ivory Coast strains. It is noteworthy that the Ivory Coast strains have an evolutionary divergent genetic background. Our results serve as a guide for the most effective use of X. tropicalis strains, and the long-term maintenance of multiple strains will contribute to further research efforts

    Nanopore direct RNA sequencing maps the complexity of Arabidopsis mRNA processing and m6A modification

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    Understanding genome organization and gene regulation requires insight into RNA transcription, processing and modification. We adapted nanopore direct RNA sequencing to examine RNA from a wild-type accession of the model plant Arabidopsis thaliana and a mutant defective in mRNA methylation (m6A). Here we show that m6A can be mapped in full-length mRNAs transcriptome-wide and reveal the combinatorial diversity of cap-associated transcription start sites, splicing events, poly(A) site choice and poly(A) tail length. Loss of m6A from 3’ untranslated regions is associated with decreased relative transcript abundance and defective RNA 30 end formation. A functional consequence of disrupted m6A is a lengthening of the circadian period. We conclude that nanopore direct RNA sequencing can reveal the complexity of mRNA processing and modification in full-length single molecule reads. These findings can refine Arabidopsis genome annotation. Further, applying this approach to less well-studied species could transform our understanding of what their genomes encode

    Measuring Redshift-Space Distortions using Photometric Surveys

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    We outline how redshift-space distortions (RSD) can be measured from the angular correlation function w({\theta}), of galaxies selected from photometric surveys. The natural degeneracy between RSD and galaxy bias can be minimized by comparing results from bins with top-hat galaxy selection in redshift, and bins based on the radial position of galaxy pair centres. This comparison can also be used to test the accuracy of the photometric redshifts. The presence of RSD will be clearly detectable with the next generation of photometric redshift surveys. We show that the Dark Energy Survey (DES) will be able to measure f(z){\sigma}_8(z) to a 1{\sigma} accuracy of (17 {\times} b)%, using galaxies drawn from a single narrow redshift slice centered at z = 1. Here b is the linear bias, and f is the logarithmic rate of change of the linear growth rate with respect to the scale factor. Extending to measurements of w({\theta}) for a series of bins of width 0.02(1 + z) over 0.5 < z < 1.4 will measure {\gamma} to a 1{\sigma} accuracy of 25%, given the model f = {\Omega}_m(z)^{\gamma}, and assuming a linear bias model that evolves such that b = 0.5 + z (and fixing other cosmological parameters). The accuracy of our analytic predictions is confirmed using mock catalogs drawn from simulations conducted by the MICE collaboration.Comment: Accepted by MNRAS, revisions include fixing of typos and clarification of the tex

    Nutritional comparison of cooked fresh and frozen vegetables

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    Dietary antioxidants (AO) are believed to contribute to the overall health benefits seen from fruit and vegetables. Despite increased public awareness of the health benefits of fruit and vegetables through campaigns such as 5 A DAY, consumption remains low. Freezing is usually regarded as destructive to AO and ascorbic acid (AA) and this has fostered a belief that fresh vegetables are nutritionally superior to frozen. In this study, AO and AA activity in commercially bought fresh and frozen vegetables were investigated and compared after a typical home cooking practice (boiling). Five different vegetables were examined: carrots, broccoli, green beans, peas and spinach. Each vegetable was bought four times from a selection of local supermarkets and green grocers in the Wirral, United Kingdom to account for variation. The oxygen radical absorbance capacity (ORAC) assay and 2, 6-dichlorophenolindophenol (DCPIP) assay were utilised to measure total antioxidant capacity (TAC) and AA content respectively. The results showed both fresh and frozen vegetables to contain AO and AA after cooking. Cooked fresh spinach and peas contained significantly (p<.05) higher levels of total AO than cooked frozen spinach and peas. However the remaining fresh and frozen vegetables (broccoli, carrots and green beans) did not appear to differ in AO content after cooking. Furthermore there was no difference between AA content in fresh and frozen cooked vegetables. The current study provides evidence against the misconception that fresh is always nutritionally superior to frozen at the point of consumption. Frozen vegetable promotion may be the way forward to increase fruit and vegetable consumption as they are generally nutritionally comparable to fresh but, cheaper, result in less waste, are more convenient and, if packaged correctly, taste the same as fresh. Further work, on a larger scale, is needed, to measure AO and AA content of fresh and frozen vegetables bought and cooked by the consumer.Mushtaq, Sohai

    Self Determination Theory and Health Behavior Interventions

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    Physical and mental health contribute to a person’s overall sense of well-being. People generally want to live happy and healthy lives, so they make decisions that will increase their well-being. Many factors contribute to our health, but health behavior is something we can modify. Health behavior interventions aim to promote healthy choices and a sense of well-being in patients. Interventions have a theoretical basis that influences the design of the intervention. Public health interventions have used self-determination theory (SDT) and its components to guide interventions that promote health behavior change in various populations. This paper will seek to understand the extent to which health interventions that incorporate SDT are successful in encouraging the behavior change they aim to promote. To situate SDT in a broader context, it will be compared to other behavior change theories. Applications of SDT in health behavior change and health support interventions will also be explored to better understand how SDT and how its components are used. Lastly, the limitations of the theory and its effectiveness will be discussed, in addition to the implications of the findings
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