1,898 research outputs found
Optimum design criteria for solar hot water systems
This paper is concerned with the optimisation of some design criteria of SHW systems intended for residential and hotel applications. For this purpose, a system model based on TRNSYS programme has been used to correlate the performance and cost effectiveness of the system with a number of key design criteria which include the Collector to Consumer Factor (FCC) expressed in m 2 of collector per consumer and the Collector to Load Factor (FCL) expressed in m 2 of collector per annual GJ of thermal load
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Identification of genes regulating migration and invasion using a new model of metastatic prostate cancer
Background: Understanding the complex, multistep process of metastasis remains a major challenge in cancer research. Metastasis models can reveal insights in tumor development and progression and provide tools to test new intervention strategies. Methods: To develop a new cancer metastasis model, we used DU145 human prostate cancer cells and performed repeated rounds of orthotopic prostate injection and selection of subsequent lymph node metastases. Tumor growth, metastasis, cell migration and invasion were analyzed. Microarray analysis was used to identify cell migration- and cancer-related genes correlating with metastasis. Selected genes were silenced using siRNA, and their roles in cell migration and invasion were determined in transwell migration and Matrigel invasion assays. Results: Our in vivo cycling strategy created cell lines with dramatically increased tumorigenesis and increased ability to colonize lymph nodes (DU145LN1-LN4). Prostate tumor xenografts displayed increased vascularization, enlarged podoplanin-positive lymphatic vessels and invasive margins. Microarray analysis revealed gene expression profiles that correlated with metastatic potential. Using gene network analysis we selected 3 significantly upregulated cell movement and cancer related genes for further analysis: EPCAM (epithelial cell adhesion molecule), ITGB4 (integrin β4) and PLAU (urokinase-type plasminogen activator (uPA)). These genes all showed increased protein expression in the more metastatic DU145-LN4 cells compared to the parental DU145. SiRNA knockdown of EpCAM, integrin-β4 or uPA all significantly reduced cell migration in DU145-LN4 cells. In contrast, only uPA siRNA inhibited cell invasion into Matrigel. This role of uPA in cell invasion was confirmed using the uPA inhibitors, amiloride and UK122. Conclusions: Our approach has identified genes required for the migration and invasion of metastatic tumor cells, and we propose that our new in vivo model system will be a powerful tool to interrogate the metastatic cascade in prostate cancer
Tropical larval and juvenile fish critical swimming speed (U-crit) and morphology data
Fish swimming capacity is a key life history trait critical to many aspects of their ecology. U-crit (critical) swimming speeds provide a robust, repeatable relative measure of swimming speed that can serve as a useful surrogate for other measures of swimming performance. Here we collate and make available one the most comprehensive datasets on U-crit swimming abilities of tropical marine fish larvae and pelagic juveniles, most of which are reef associated as adults. The dataset includes U-crit speed measurements for settlement stage fishes across a large range of species and families obtained mostly from field specimens collected in light traps and crest nets; and the development of swimming abilities throughout ontogeny for a range of species using reared larvae. In nearly all instances, the size of the individual was available, and in many cases, data include other morphological measurements (e.g. “propulsive area”) useful for predicting swimming capacity. We hope these data prove useful for further studies of larval swimming performance and other broader syntheses
Using On-Farm Demonstrations to Evaluate Newly Developed Cool-Season Forages in the Southeastern USA
Multiple demonstration sites throughout Florida were designed to evaluate and provide hands-on producer and county faculty access to newly developed cool-season winter forage crops that can be grown in the southeastern United States. Research funding for these projects was provided by the Dairy Research and Education Project, supported through the Georgia/Florida Dairy Industry check-off dollars. Early adopter producers interested in evaluating forages were identified for this cooperation. Long-term goals are to have the early adopter producer aid in the trialing and dissemination of information about improved varieties.
Cool-season forages for use on southeastern US livestock operations benefit the producer in providing highly nutritional greenchop or silage crop for livestock, winter cover to provide erosion and leaching protection on cultivated acreage, potentially recycle nutrients or remove significant nutrients from the forage system, and serve as a sentinel plots to help identify new or emerging pest problems related to forage production.
We also focus developing forages for both low and high end input systems that address environmental issues related to N and P in the soils. In the southeastern U.S. particularly in Florida, nitrogen and phosphorus accumulate in many production fields and these nutrients impact surface and ground water resources. We participate with the Florida Department of Agriculture and the dairy and beef cattle industry to develop “best management practices” (BMPs) that guide producers to lessen their negative impacts on the environment and improve upon their operation’s sustainability and economic returns. This effort has led to the release of new cultivars from the University of Florida’s Forage Program. While we focus, primarily, on cool-season small grains and ryegrass, our program also includes breeding other subtropical forage species for adaptation to our environment and to improve adoption of BMPs
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A comparison of the survival and migratory behavior of hatchery-reared and naturally reared steelhead smolts in the Alsea River and estuary, Oregon, using acoustic telemetry
We tracked three groups of steelhead Oncorhynchus mykiss smolts implanted with acoustic transmitters to determine whether the degree of hatchery domestication or the juvenile rearing environment (hatchery raceway versus natural stream) influenced migration timing and survival in the Alsea River and estuary, Oregon. Two groups consisted of age-1 smolts reared in concrete raceways. One hatchery-reared group (traditional brood group) was derived from the traditional Alsea River broodstock initially developed in the 1950s. The second hatchery-reared group (new brood group) was derived from naturally reared Alsea River adult steelhead that were captured and spawned at the hatchery beginning in the winter of 2000-2001. The third group (naturally reared group) consisted of age-2 naturally reared smolts captured in a downstream migrant trap located in a tributary stream near the hatchery. We placed transmitters in 74 traditional brood smolts, 76 new brood smolts, and 72 naturally reared smolts. Thirty-one acoustic receivers were located throughout the Alsea River and estuary and in the ocean offshore of the river mouth to monitor smolt movement. We found no significant difference between groups in their survival to the head of tide or to the mouth of the estuary. Most smolts from all three groups were detected at the head of tide (87% of fish from the traditional brood group, 78% from the new brood group, and 84% from the naturally reared group). However, survival was poor in the lower estuary for all three groups; we estimated that only 37% of the traditional brood group, 45% of the new brood group, and 47% of the naturally reared group survived to the ocean. The timing of migration through the river was highly variable in all three groups, and we found no significant differences in the rate of downstream movement from the release site to the head of tide. Mean residence time within the estuary was similar for all groups, although smolts from the naturally reared group showed less variability in estuary residence time than hatchery-reared smolts.Keywords: marine survival, Oncorhynchus mykiss, juvenile salmonid
Hydrogeology and Ground-Water Availability in Southwest McLean and Southeast Tazewell Counties Part 2: Aquifer Modeling and Final Report
An assessment of the aquifer characteristics and ground-water availability has been
completed for one of the largest sand-and-gravel aquifers in Illinois, the Sankoty-Mahomet Sand
aquifer, in the confluence area of the Mahomet and Mackinaw Bedrock Valleys in McLean and
Tazewell Counties. Based on data gathered during the field portion of the study, a ground-water flow
model was developed that simulates the effects of a hypothetical well field for various locations within
the study area. It was used to estimate the quantity of ground water that could be withdrawn from the
aquifer within the study area. The model was calibrated to match water levels measured in area wells
in 1994 and to match the baseflow gains and losses in the Mackinaw River and Sugar Creek. A
hypothetical well field, pumping 15 million gallons a day (mgd), was simulated at four locations, The
results varied from a maximum drawdown of 8 feet in the Hopedale scenario to 55 feet in the
Armington scenario. If a well field similar to the well fields modeled were installed in the study area,
as many as 400 private wells may be impacted. In certain areas near the Mackinaw River, a well field
would greatly reduce the ground-water portion of baseflow entering the Mackinaw River. Pumping
three of the well fields together, at a total rate of 37.5 mgd, indicated that the aquifer should be able
to sustain withdrawals in excess of 37.5 mgd if the pumpage is distributed in the study area
Embodied cognitive ecosophy: the relationship of mind, body, meaning and ecology
The concept of embodied cognition has had a major impact in a number of disciplines. The extent of its consequences on general knowledge and epistemology are still being explored. Embodied cognition in human geography has its own traditions and discourses but these have become somewhat isolated in the discipline itself. This paper argues that findings in other disciplines are of value in reconceptualising embodied cognition in human geography and this is explored by reconsidering the concept of ecosophy. Criticisms of ecosophy as a theory are considered and recent work in embodied cognition is applied to consider how such criticisms might be addressed. An updated conceptualisation is proposed, the embodied cognitive ecosophy, and three characteristics arising from this criticism and synthesis are presented with a view to inform future discussions of ecosophy and emotional geography
The Hamiltonian limit of (3+1)D SU(3) lattice gauge theory on anisotropic lattices
The extreme anisotropic limit of Euclidean SU(3) lattice gauge theory is
examined to extract the Hamiltonian limit, using standard path integral Monte
Carlo (PIMC) methods. We examine the mean plaquette and string tension and
compare them to results obtained within the Hamiltonian framework of Kogut and
Susskind. The results are a significant improvement upon previous Hamiltonian
estimates, despite the extrapolation procedure necessary to extract
observables. We conclude that the PIMC method is a reliable method of obtaining
results for the Hamiltonian version of the theory. Our results also clearly
demonstrate the universality between the Hamiltonian and Euclidean formulations
of lattice gauge theory. It is particularly important to take into account the
renormalization of both the anisotropy, and the Euclidean coupling ,
in obtaining these results.Comment: 10 pages, 11 figure
Role of Electronic Data Exchange in an International Outbreak Caused by Salmonella enterica Serotype Typhimurium DT204b
From July through September 2000, patients in five European countries were infected with a multidrug-resistant strain of Salmonella Typhimurium DT204b. Epidemiologic investigations were facilitated by the transmission of electronic images (Tagged Image Files) of pulsed-field gel electrophoresis profiles. This investigation highlights the importance of standardized protocols for molecular typing in international outbreaks of foodborne disease
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