99 research outputs found
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Sensing what fish feel about passage through three different low-head hydropower turbines
Knowing the kinds of physical stress experienced by fish passing through hydropower turbines can help optimise technologies and improve fish passage. This paper assesses the hydraulic conditions experienced through three different low-head turbines, taken using an autonomous sensor: a VLH, Archimedes screw and horizontal Kaplan turbine. A total of 127 Sensor Fish deployments were undertaken across all three turbines, generating 82 valid datasets. Decompression was rare at the VLH and screw turbines and rarely fell more than 10 kPa below atmospheric pressure. In contrast, the Kaplan was capable of generating pressures as low as 55.5 kPa (approximately 45 kPa below atmospheric pressure), over shorter periods of time. Severer ratios of pressure changes could therefore be expected for both surface and depth acclimated fish at the Kaplan when compared to the other turbines. Strike was another possible source of fish injury (detected in 69-100% of deployments), and although strike severity was highest at the Kaplan, strike was more likely to be encountered at the screw and VLH than the Kaplan turbine. Shear only occurred near the blades of the Kaplan and not at severe levels. The results demonstrate that low-head hydropower facilities are not without their risks for downstream migrating fish
Ultrasound-enhanced ocular delivery of dexamethasone sodium phosphate: An in vivo study
Background
The eye\u27s unique anatomy and its physiological and anatomical barriers can limit effective drug delivery into the eye. Methods
An in vivo study was designed to determine the effectiveness and safety of ultrasound application in enhancing drug delivery in a rabbit model. Permeability of a steroid ophthalmic drug, dexamethasone sodium phosphate, was investigated in ultrasound- and sham-treated cases. For this study, an eye cup filled with dexamethasone sodium phosphate was placed on the cornea. Ultrasound was applied at intensity of 0.8 W/cm2 and frequency of 400 or 600 kHz for 5 min. The drug concentration in aqueous humor samples, collected 90 min after the treatment, was determined using chromatography methods. Light microscopy observations were done to determine the structural changes in the cornea as a result of ultrasound application. Results
An increase in drug concentration in aqueous humor samples of 2.8 times (p \u3c 0.05) with ultrasound application at 400 kHz and 2.4 times (p \u3c 0.01) with ultrasound application at 600 kHz was observed as compared to sham-treated samples. Histological analysis showed that the structural changes in the corneas exposed to ultrasound predominantly consisted of minor epithelial disorganization. Conclusions
Ultrasound application enhanced the delivery of an anti-inflammatory ocular drug, dexamethasone sodium phosphate, through the cornea in vivo. Ultrasound-enhanced ocular drug delivery appears to be a promising area of research with a potential future application in a clinical setting
Transcriptome sequencing in an ecologically important tree species: assembly, annotation, and marker discovery
<p>Abstract</p> <p>Background</p> <p>Massively parallel sequencing of cDNA is now an efficient route for generating enormous sequence collections that represent expressed genes. This approach provides a valuable starting point for characterizing functional genetic variation in non-model organisms, especially where whole genome sequencing efforts are currently cost and time prohibitive. The large and complex genomes of pines (<it>Pinus </it>spp.) have hindered the development of genomic resources, despite the ecological and economical importance of the group. While most genomic studies have focused on a single species (<it>P. taeda</it>), genomic level resources for other pines are insufficiently developed to facilitate ecological genomic research. Lodgepole pine (<it>P. contorta</it>) is an ecologically important foundation species of montane forest ecosystems and exhibits substantial adaptive variation across its range in western North America. Here we describe a sequencing study of expressed genes from <it>P. contorta</it>, including their assembly and annotation, and their potential for molecular marker development to support population and association genetic studies.</p> <p>Results</p> <p>We obtained 586,732 sequencing reads from a 454 GS XLR70 Titanium pyrosequencer (mean length: 306 base pairs). A combination of reference-based and <it>de novo </it>assemblies yielded 63,657 contigs, with 239,793 reads remaining as singletons. Based on sequence similarity with known proteins, these sequences represent approximately 17,000 unique genes, many of which are well covered by contig sequences. This sequence collection also included a surprisingly large number of retrotransposon sequences, suggesting that they are highly transcriptionally active in the tissues we sampled. We located and characterized thousands of simple sequence repeats and single nucleotide polymorphisms as potential molecular markers in our assembled and annotated sequences. High quality PCR primers were designed for a substantial number of the SSR loci, and a large number of these were amplified successfully in initial screening.</p> <p>Conclusions</p> <p>This sequence collection represents a major genomic resource for <it>P. contorta</it>, and the large number of genetic markers characterized should contribute to future research in this and other pines. Our results illustrate the utility of next generation sequencing as a basis for marker development and population genomics in non-model species.</p
Submission to Canadian Government Consultation on a Modern Copyright Framework for AI and the Internet of Things
We are grateful for the opportunity to participate in the Canadian Government’s consultation on a modern copyright framework for AI and the Internet of Things. Below, we present some of our research findings relating to the importance of flexibility in copyright law to permit text and data mining (“TDM”). As the consultation paper recognizes, TDM is a critical element of artificial intelligence. Our research supports the adoption of a specific exception for uses of works in TDM to supplement Canada’s existing general fair dealing exception.
Empirical research shows that more publication of citable research takes place in countries with “open” research exceptions -- that is, research exceptions that are open to all uses (e.g. reproduction and communication), to all works, and to all users. Empirical research also shows that text and data mining research is promoted through exceptions that more specifically authorize text and data mining research. While these studies are preliminary and we are still improving on them, they provide evidence that supports the approach of combining a general research exception with a more specific data mining exception
The Ursinus Weekly, October 14, 1976
Ursinus news in brief: Parsons admitted to Sacred Heart ; Reiner, Bozorth receive awards; Grant supports psych research; Staskiel to make TV debut • Freshmen elect officers • Nine join faculty • USGA holds carnival • Economics club meets • Ursinus and the arts • Another look at alumni • Coming campus events • WPAZ offers intern program • Harriers surging • LV, Johns Hopkins beat Karas\u27 Bears • Sixers: ready for all new NBA • Saturday\u27s gamehttps://digitalcommons.ursinus.edu/weekly/1058/thumbnail.jp
On the contribution of the horizontal sea-bed displacements into the tsunami generation process
The main reason for the generation of tsunamis is the deformation of the
bottom of the ocean caused by an underwater earthquake. Usually, only the
vertical bottom motion is taken into account while the horizontal co-seismic
displacements are neglected in the absence of landslides. In the present study
we propose a methodology based on the well-known Okada solution to reconstruct
in more details all components of the bottom coseismic displacements. Then, the
sea-bed motion is coupled with a three-dimensional weakly nonlinear water wave
solver which allows us to simulate a tsunami wave generation. We pay special
attention to the evolution of kinetic and potential energies of the resulting
wave while the contribution of the horizontal displacements into wave energy
balance is also quantified. Such contribution of horizontal displacements to
the tsunami generation has not been discussed before, and it is different from
the existing approaches. The methods proposed in this study are illustrated on
the July 17, 2006 Java tsunami and some more recent events.Comment: 30 pages; 14 figures. Accepted to Ocean Modelling. Other authors
papers can be downloaded at http://www.lama.univ-savoie.fr/~dutykh
The Ursinus Weekly, February 26, 1976
WRUC is on the air • Dr. Parsons tells of visit to Germany • Election results • Student interns join WPAZ radio staff • Student-Board Comm. meets • Loyalty fund is thriving • Spiropoulos examines J.F.K. assassination • Free Library • Editorial: Food for thought or? • U.C. speakers • Editorial: Energy woes are for real and jobs are at stake • Careers vs. liberal arts • Viewpoint: Mr. Bloom\u27s point is worth repeating • Bearpit action • Seminars for women offered: Women and the law; Women and finance • JV Bears play .500 • Bears do swim! • Our bouncing Bears • Focus: Greg Thren • Spring feverhttps://digitalcommons.ursinus.edu/weekly/1052/thumbnail.jp
Stellar Structure Modeling using a Parallel Genetic Algorithm for Objective Global Optimization
Genetic algorithms are a class of heuristic search techniques that apply
basic evolutionary operators in a computational setting. We have designed a
fully parallel and distributed hardware/software implementation of the
generalized optimization subroutine PIKAIA, which utilizes a genetic algorithm
to provide an objective determination of the globally optimal parameters for a
given model against an observational data set. We have used this modeling tool
in the context of white dwarf asteroseismology, i.e., the art and science of
extracting physical and structural information about these stars from
observations of their oscillation frequencies. The efficient, parallel
exploration of parameter-space made possible by genetic-algorithm-based
numerical optimization led us to a number of interesting physical results: (1)
resolution of a hitherto puzzling discrepancy between stellar evolution models
and prior asteroseismic inferences of the surface helium layer mass for a DBV
white dwarf; (2) precise determination of the central oxygen mass fraction in a
white dwarf star; and (3) a preliminary estimate of the astrophysically
important but experimentally uncertain rate for the ^12C(alpha,gamma)^16O
nuclear reaction. These successes suggest that a broad class of
computationally-intensive modeling applications could also benefit from this
approach.Comment: 22 pages, minor changes, to appear in Journal of Computational
Physics (JCPH2002-0129), software available at
http://whitedwarf.org/parallel
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