182 research outputs found
Student Loan Defaulters Compared with Repayers: A Texas Case Study
This research compares student loan defaulters\u27 and repayers\u27 attitudes about vocational education in Texas. Interviews with loan recipients indicate that student loan defaults are affected by how much students are pressured to enroll in a program, their understanding of the loan program when they first sign an application, and how well their vocational education equips them to take a job. Such findings are increasingly important to policymakers, as the struggle for federal dollars increases and vocational students remain one of the largest groups of recipients and defaulters in the Federal Stafford Loan Program (formerly the Guaranteed Student Loan Program)
Herbicide Evaluation in Arkansas Rice, 1997
Weed control is economically important for production of rice, a major crop in Arkansas. These findings summarize efforts of the team of Arkansas scientists working on weed control strategies for rice during 1997. Various technologies were evaluated in field studies at five locations involving the major weed problems and rice production systems used in the state. Results from these studies will add to the arsenal of weed control options for producers. Highlights include synergists and safeners for herbicides to aid in control of propanil-resistant barnyardgrass; herbicides and flooding techniques for control of red rice and other weeds; and the use of transgenic rice cultivars for broadspectrum weed control. The preliminary results reported here generally warrant further testing for more advanced findings and for the labeling of new technologies, and finally are the basis for updating safe, effective, and economical recommendations to Arkansas rice producers
In Vitro Scaffold Construction for a Bio-artificial Liver
The main focus of this investigation is to design a scaffold that will accommodate a growing Bio-Artificial Liver (BAL) with oxygen. The two design objectives are to find the maximum length and the distance between the artificial capillaries of the scaffold to provide adequate oxygen supply above 1.98 x 10-19 g/um3 to prevent hypoxia to the growing liver tissues. By utilizing industrial modeling software, FIDAP and GAMBIT, a model of a single capillary with liver tissue attached directly was constructed to simulate the oxygen delivery by means of diffusion and convection from the capillary wall to the tissue and the uptake by metabolism. From the results obtained, it was concluded that diffusion, not convection of the oxygen flow within the capillary was the dominant process of oxygen transport throughout the tissue. The maximum distance traveled into the tissue with capillary length of 60 ?m was 147 ?m from the capillary at the inlet side of the tissue while diffusion at the outlet tissue was at a modest 108 ?m. These values are unacceptable for the feasible construction of oxygen transport system solely based on diffusion. Thus, this investigation concludes that novel methods of greater complexity are needed to construct a more efficient and economically applicable oxygen delivery system for the mass production of bio-organs
Inter-agency Working Group for Airborne Data and Telemetry Systems (IWGADTS)
The Interagency Coordinating Committee for Airborne Geosciences Research and Applications (ICCAGRA) was established to improve cooperation and communication among agencies sponsoring airborne platforms and instruments for research and applications, and to serve as a resource for senior level management on airborne geosciences issues. The Interagency Working Group for Airborne Data and Telecommunications Systems (IWGADTS) is a subgroup to ICCAGRA for the purpose of developing recommendations leading to increased interoperability among airborne platforms and instrument payloads, producing increased synergy among research programs with similar goals, and enabling the suborbital layer of the Global Earth Observing System of Systems
Spectrally Resolved Synthetic Aperture Imaging Interferometer
The Spectrally Resolved Synthetic-Aperture Imaging Interferometer (SRSAII) is a system proposed to provide high-resolution and high-sensitivity measurements of astronomical objects. SRSAII uses long baseline interferometric methods to achieve the resolution and low-noise, high time-precision detection to achieve the sensitivity. The primary goal of the SRSAII study was to lay out a framework for using new optical physics technologies to directly resolve, both spatially and spectrally, the disk of an exoplanet. In addition to the ambitious goal of directly resolving an exoplanet, the SRSAII team also sought to identify science opportunities achievable with intermediate system configurations which may offer resolution significantly higher than the current state of the art, but insufficient for direct resolution of an exoplanetary disk. An operational SRSAII system can function with essentially arbitrarily large baselines, achieving correspondingly high angular resolution. The primary limitation occurs in the system sensitivity, which became the major technical focus for study. In this report, we compare the predicted performance (sensitivity in SNR (Signal-to-Noise Ratio) along with angular resolution) of three interferometric techniques: direct detection (also known as homodyne interferometry), multi-channel intensity interferometry (using the Hanbury Brown and Twiss effect), and multi-channel heterodyne interferometry (using an optical frequency comb as a local oscillator). Additionally, quantum-assisted interferometry is also explored as a prospective enhancement of established methods. This report presents a survey of the technologies that enable the SRSAII techniques - optical frequency combs, single photon detectors, and photonic integrated circuits. These technologies are the basis of methods critical to SRSAII's success: precision timing, length and frequency metrology, sensitive photodetection, fine-scale wavelength filtering, and dense multi-channel operation. Lastly, we give some notional performance metrics and propose some possible experimental observations
CURIOS:Web-based presentation and management of linked datasets
A number of systems extend the traditional web and Web 2.0 technologies by providing some form of integration with semantic web data [1,2,3]. These approaches build on tested content management systems (CMSs) for facilitating users in the semantic web. However, instead of directly managing existing linked data, these systems provide a mapping between their own data model to linked datasets using an RDF or OWL vocabulary. This sort of integration can be seen as a read-only or write-only approach, where linked data is either imported into or exported from the system. The next step in this evolution of CMSs is a full integration with linked data: allowing ontology instances, already published as linked data, to be directly managed using widely used web content management platforms. The motivation is to keep data (i.e., linked data repositories) loosely-coupled to the tool used to maintain them (i.e., the CMS). In this poster, we extend [3], a query builder for SPARQL, with an update mechanism to allow users to directly manage their linked data from within the CMS. To make the system sustainable and extensible in future, we choose to use Drupal as the default CMS and develop a module to handle query/update against a triple store. Our system, which we call a Linked Data Content Management System (Linked Data CMS) [4], performs similar operations to those of a traditional CMS but whereas a traditional CMS uses a data model of content types stored in some relational database backend, a Linked Data CMS performs CRUD (create, read, update, and delete) operations on linked data held in a triple store. Moreover, we show how the system can assist users in producing and consuming linked data in the cultural heritage domain and introduce 2 case studies used for system evaluation
Shape Memory Alloy Actuator Design: CASMART Collaborative Best Practices
Upon examination of shape memory alloy (SMA) actuation designs, there are many considerations and methodologies that are common to them all. A goal of CASMART's design working group is to compile the collective experiences of CASMART's member organizations into a single medium that engineers can then use to make the best decisions regarding SMA system design. In this paper, a review of recent work toward this goal is presented, spanning a wide range of design aspects including evaluation, properties, testing, modeling, alloy selection, fabrication, actuator processing, design optimization, controls, and system integration. We have documented each aspect, based on our collective experiences, so that the design engineer may access the tools and information needed to successfully design and develop SMA systems. Through comparison of several case studies, it is shown that there is not an obvious single, linear route a designer can adopt to navigate the path of concept to product. SMA engineering aspects will have different priorities and emphasis for different applications
Observational Study Design in Veterinary Pathology, Part 1: Study Design
Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature. Investigators should recognize the importance of creativity, insight, and innovation in devising studies that solve problems and fill important gaps in knowledge. Studies should focus on specific and testable hypotheses, questions, or objectives. The methodology is developed to support these goals. We consider the merits and limitations of different types of analytic and descriptive studies, as well as of prospective vs retrospective enrollment. Investigators should define clear inclusion and exclusion criteria and select adequate numbers of study subjects, including careful selection of the most appropriate controls. Studies of causality must consider the temporal relationships between variables and the advantages of measuring incident cases rather than prevalent cases. Investigators must consider unique aspects of studies based on archived laboratory case material and take particular care to consider and mitigate the potential for selection bias and information bias. We close by discussing approaches to adding value and impact to observational studies. Part 2 of the series focuses on methodology and validation of methods
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Thermal and Air Quality Acceptability in Buildings that Reduce Energy by Reducing Minimum Airflow from Overhead Diffusers
There is great energy-saving potential in reducing variable air volume (VAV) box minimum airflow setpoints.In the past, setpoints have been maintained at high levels because of three concerns: 1) low flows might cause the occupants draft discomfort from insufficient mixing of diffuser discharge air, 2) inability of VAV boxes to control at low flows, and 3) poor air quality resulting from a combination of poor control and insufficient diffuser mixing. It is worth examining these concerns to see whether they are justified. The controller accuracy and stability have recently been addressed by RP 1353, in which VAV boxes were found to control well at very low flow levels. The diffuser mixing issue and impact on comfort are addressed in this research project, RP 1515.RP 1515 is a combined field and laboratory study, in which occupants’ thermal comfort and air quality satisfaction is evaluated in the field under reduced minimum VAV flow rate setpoints, and the mixing performance of diffusers is measured in the laboratory. The laboratory portion was performed with co-funding from Price Industries. Additional co-funding from the California Energy Commission’s PIER program allowed us to quantify the HVAC energy savings resulting from the reduced flows in the field study buildings.
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Challenges of early renal cancer detection: symptom patterns and incidental diagnosis rate in a multicentre prospective UK cohort of patients presenting with suspected renal cancer.
OBJECTIVES: To describe the frequency and nature of symptoms in patients presenting with suspected renal cell carcinoma (RCC) and examine their reliability in achieving early diagnosis. DESIGN: Multicentre prospective observational cohort study. SETTING AND PARTICIPANTS: Eleven UK centres recruiting patients presenting with suspected newly diagnosed RCC. Symptoms reported by patients were recorded and reviewed. Comprehensive clinico-pathological and outcome data were also collected. OUTCOMES: Type and frequency of reported symptoms, incidental diagnosis rate, metastasis-free survival and cancer-specific survival. RESULTS: Of 706 patients recruited between 2011 and 2014, 608 patients with a confirmed RCC formed the primary study population. The majority (60%) of patients were diagnosed incidentally. 87% of patients with stage Ia and 36% with stage III or IV disease presented incidentally. Visible haematuria was reported in 23% of patients and was commonly associated with advanced disease (49% had stage III or IV disease). Symptomatic presentation was associated with poorer outcomes, likely reflecting the presence of higher stage disease. Symptom patterns among the 54 patients subsequently found to have a benign renal mass were similar to those with a confirmed RCC. CONCLUSIONS: Raising public awareness of RCC-related symptoms as a strategy to improve early detection rates is limited by the fact that related symptoms are relatively uncommon and often associated with advanced disease. Greater attention must be paid to the feasibility of screening strategies and the identification of circulating diagnostic biomarkers
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