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Sample records for study bases study

  1. Data base management study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Data base management techniques and applicable equipment are described. Recommendations which will assist potential NASA data users in selecting and using appropriate data base management tools and techniques are presented. Classes of currently available data processing equipment ranging from basic terminals to large minicomputer systems were surveyed as they apply to the needs of potential SEASAT data users. Cost and capabilities projections for this equipment through 1985 were presented. A test of a typical data base management system was described, as well as the results of this test and recommendations to assist potential users in determining when such a system is appropriate for their needs. The representative system tested was UNIVAC's DMS 1100.

  2. Space base antenna study

    NASA Technical Reports Server (NTRS)

    Deerkoski, L. F.

    1971-01-01

    The field of view required of the space base antenna is defined for both the tracking and data relay satellite link and detached module links. The gain requirements are established and the feasibility of alternative antenna configurations using phased arrays and reflectors are considered. One recommended and one alternative configuration are presented for each of the required links.

  3. Brain-Science Based Cohort Studies

    ERIC Educational Resources Information Center

    Koizumi, Hideaki

    2011-01-01

    This article describes a number of human cohort studies based on the concept of brain-science and education. These studies assess the potential effects of new technologies on babies, children and adolescents, and test hypotheses drawn from animal and genetic case studies to see if they apply to people. A flood of information, virtual media,…

  4. Systems engineering studies of lunar base construction

    NASA Technical Reports Server (NTRS)

    Morgenthaler, George W.

    1991-01-01

    Many ingenious concepts have been proposed for lunar base construction, but few systematic studies exist which relate time-consistent lunar base construction technologies and the choice of lunar base approach with the long-term SEI objectives - i.e., lunar indigenous base construction and Mars Exploration equipment development. To fill this gap, CSC has taken a two-pronged approach. First, the Center undertook basic geotechnical investigations of lunar soil, fabrication of a scale prototype of a lunar construction crane, a multi-robot construction team laboratory experiment, and a preliminary design of lunar base structures. Second, during Jun. and Jul. 1991 two lunar base construction systems engineering studies were accomplished - a 'near term lunar base' study, and a 'far-term lunar base' study. The goals of these studies were to define the major lunar base construction research problems in consistent technology/construction frameworks, and to define design requirements for construction equipment such as a lunar crane and a regolith mover. The 'near-term lunar base' study examined three different construction concepts for a lunar base comprised of pre-fabricated, pre-tested, Space Station Freedom-type modules, which would be covered with regolith shielding. Concept A used a lunar crane for unloading and transportation; concept B, a winch and cart; and concept C, a walker to move the modules from the landing site to the base site and assemble them. To evaluate the merits of each approach, calculations were made of mass efficiency measure, source mass, reliability, far-term base mass, Mars base mass, and base assembly time. The model thus established was also used to define the requirements for crane speed and regolith mover m(sup 3)/sec rates. A major problem addressed is how to 'mine' the regolith and stack it over the habitats as shielding. To identify when the cost of using indigenous lunar materials to construct the base exceeds the cost of development and

  5. Systems engineering studies of lunar base construction

    NASA Astrophysics Data System (ADS)

    Morgenthaler, George W.

    1991-11-01

    Many ingenious concepts have been proposed for lunar base construction, but few systematic studies exist which relate time-consistent lunar base construction technologies and the choice of lunar base approach with the long-term SEI objectives - i.e., lunar indigenous base construction and Mars Exploration equipment development. To fill this gap, CSC has taken a two-pronged approach. First, the Center undertook basic geotechnical investigations of lunar soil, fabrication of a scale prototype of a lunar construction crane, a multi-robot construction team laboratory experiment, and a preliminary design of lunar base structures. Second, during Jun. and Jul. 1991 two lunar base construction systems engineering studies were accomplished - a 'near term lunar base' study, and a 'far-term lunar base' study. The goals of these studies were to define the major lunar base construction research problems in consistent technology/construction frameworks, and to define design requirements for construction equipment such as a lunar crane and a regolith mover. The 'near-term lunar base' study examined three different construction concepts for a lunar base comprised of pre-fabricated, pre-tested, Space Station Freedom-type modules, which would be covered with regolith shielding. Concept A used a lunar crane for unloading and transportation; concept B, a winch and cart; and concept C, a walker to move the modules from the landing site to the base site and assemble them. To evaluate the merits of each approach, calculations were made of mass efficiency measure, source mass, reliability, far-term base mass, Mars base mass, and base assembly time. The model thus established was also used to define the requirements for crane speed and regolith mover m(sup 3)/sec rates. A major problem addressed is how to 'mine' the regolith and stack it over the habitats as shielding. To identify when the cost of using indigenous lunar materials to construct the base exceeds the cost of development and

  6. Case studies in outcome-based education.

    PubMed

    Davis, Margery H; Amin, Zubair; Grande, Joseph P; O'Neill, Angela E; Pawlina, Wojciech; Viggiano, Thomas R; Zuberi, Rukhsana

    2007-09-01

    Outcome-based education is one of the most significant global developments in medical education in recent years. This paper presents four case studies of outcome-based education from medical schools in different parts of the world; Scotland; USA; Pakistan; and Singapore. The outcome-based curricula have either been in place for some time, are evolving or are at the planning proposal stage. The outcomes, change process and implementation of the outcome-based approach are described. Variation in the extent to which each medical school has implemented outcome-based education is discussed and key points for successful implementation are highlighted. This paper is based on the pre-conference symposium "outcome-based curricula: global perspectives" presented by the authors at the 4th Asia Pacific Medical Education Conference (APMEC) in Singapore, 8-11 February, 2007. PMID:18236260

  7. Competency Based Education: A Sociological Study.

    ERIC Educational Resources Information Center

    Graham, Thomas E.

    This study focuses on the Competency Based Education (CBE) movement in a small Ohio school district, asking whether it represents radical change or reenforces status-quo social stratification. CBE was a product of the recent public demand for more educational accountability. It is a radical shift from traditional U.S. education insofar as it…

  8. The Conceptual Bases of Study Strategy Inventories

    ERIC Educational Resources Information Center

    Entwistle, Noel; McCune, Velda

    2004-01-01

    This article describes the historical origins and development of a series of well-known study strategy inventories and seeks to identify their conceptual bases. The theories and evidence influencing the development of 6 contrasting instruments are considered before examining empirical evidence of similarities and differences between the…

  9. ASTM/NBS base stock consistency study

    SciTech Connect

    Frassa, K.A.

    1980-11-01

    This paper summarizes the scope of a cooperative ASTM/NBS program established in June 1979. The contemplated study will ascertain the batch-to-batch consistency of re-refined and virgin base stocks manufactured by various processes. For one year, approximately eight to ten different base stocks samples, will be obtained by NBS every two weeks. One set of bi-monthly samples will be forwarded to each participant, on a coded basis monthly. Seven to eight samples will be obtained from six different re-refining processes and two virgin oil samples from a similar manufacturing process. The participants will report their results on a monthly basis. The second set of samples will be retained by NBS for an interim monthly sample study, if required, based on data analysis. Each sample's properties will be evaluated using various physical tests, chemical tests, and bench tests. The total testing program should define the batch-to-batch base stock consistency short of engine testing.

  10. Study of PDMS based magnetorheological elastomers

    NASA Astrophysics Data System (ADS)

    Tian, T. F.; Zhang, X. Z.; Li, W. H.; Alici, G.; Ding, J.

    2013-02-01

    The fabrication of conventional magnetorheological elastomers (MRE) is usually taken more than 1 day because the conventional matrixes such as natural rubber and silicone rubber need long curing time to become solid state. This study presents a rapid method for fabricating MRE within 90 minutes by using poly(dimethylsiloxane) (PDMS) as the matrix thanks to the rapid curing of PDMS in high temperature. A total of four PDMS based MRE samples were fabricated. Their mechanical and rheological properties under both steady-state and dynamic loading conditions were tested with a parallel-plate rheometer. Additionally, the microstructures of the PDMS based MREs were also observed by SEM and compared with the silicone rubber based MRE.

  11. Study of cluster headache: A hospital-based study

    PubMed Central

    Bhargava, Amita; Pujar, Guruprasad S.; Banakar, Basavaraj F.; Shubhakaran, K; Kasundra, Gaurav; Bhushan, Bharat

    2014-01-01

    Introduction: Cluster headache (CH) is uncommon and most painful of all primary headaches, and continues to be managed suboptimally because of wrong diagnosis. It needs to be diagnosed correctly and specifically treated. There are few studies and none from this region on CH. Materials and Methods: To study the detailed clinical profile of CH patients and to compare them among both the genders. Study was conducted at Mahatma Gandhi hospital, Jodhpur (from January 2011to December 2013). Study comprises 30 CH patients diagnosed according to International Headache Society guidelines (ICHD-II). Routine investigations and MRI brain was done in all patients. All measurements were reported as mean ± SD. Categorical variables were compared using the Chi-square test, and continuous variables were compared using Student's t-test. SPSS for Windows, Version 16.0, was used for statistical analyses with the significance level set at P = 0.05. Results: M: F ratio was 9:1. Age at presentation was from 22-60 years (mean - 38 years). Latency before diagnosis was 3 months-12 years (mean - 3.5 years). All suffered from episodic CH and aura was found in none. Pain was strictly unilateral (right-19, left-11), predominantly over temporal region-18 (60%). Pain intensity was severe in 27 (90%) and moderate in 3 (10%). Pain quality was throbbing in 12 (40%). Peak intensity was reached in 5 minutes-30 minutes and attack duration varied from 30 minutes to 3 hours (mean - 2.45 hours). Among autonomic features, conjunctival injection-23 (76.6%) and lacrimation-25 (83.3%) were most common. Restlessness during episode was found in 80%. CH duration varied from 10 days to 12 weeks. Circadian periodicity for attacks was noted in 24 (80%). Conclusion: Results are consistent with other studies on many accounts, but is different from Western studies with respect to low frequency of family history, chronic CH, restlessness and aura preceeding the attack. Detailed elicitation of history is paramount as

  12. Si-based Nanoparticles: a biocompatibility study

    NASA Astrophysics Data System (ADS)

    Rivolta, I.; Lettiero, B.; Panariti, A.; D'Amato, R.; Maurice, V.; Falconieri, M.; Herlein, N.; Borsella, E.; Miserocchi, G.

    2010-10-01

    Exposure to silicon nanoparticles (Si-NPs) may occur in professional working conditions or for people undergoing a diagnostic screening test. Despite the fact that silicon is known as a non-toxic material, in the first case the risk is mostly related to the inhalation of nanoparticles, thus the most likely route of entry is across the lung alveolar epithelium. In the case of diagnostic imaging, nanoparticles are usually injected intravenously and Si-NPs could impact on the endothelial wall. In our study we investigated the interaction between selected Si-based NPs and an epithelial lung cell line. Our data showed that, despite the overall silicon biocompatibility, however accurate studies of the potential toxicity induced by the nanostructure and engineered surface characteristics need to be accurately investigated before Si nanoparticles can be safely used for in vivo applications as bio-imaging, cell staining and drug delivery.

  13. Metabonomics-based omics study and atherosclerosis.

    PubMed

    Wu, Duo-Jiao; Zhu, Bi-Jun; Wang, Xiang-Dong

    2011-01-01

    Atherosclerosis results from dyslipidemia and systemic inflammation, associated with the strong metabolism and interaction between diet and disease. Strategies based on the global profiling of metabolism would be important to define the mechanisms involved in pathological alterations. Metabonomics is the quantitative measurement of the dynamic multiparametric metabolic response of living systems to pathophysiological stimuli or genetic modification. Metabonomics has been used in combination with proteomics and transcriptomics as the part of a systems biology description to understand the genome interaction with the development of atherosclerosis. The present review describes the application of metabonomics to explore the potential role of metabolic disturbances and inflammation in the initiation and development of atherosclerosis. Metabonomics-based omics study offers a new potential for biomarker discovery by disentangling the impacts of diet, environment and lifestyle.

  14. Studies of anisotropy of iron based superconductors

    SciTech Connect

    Murphy, Jason A.

    2013-01-01

    To study the electronic anisotropy in iron based superconductors, the temperature dependent London penetration depth, Δλ(T), have been measured in several compounds, along with the angular dependent upper critical field, Hc2(T). Study was undertaken on single crystals of Ba(Fe1-xCox)2As2 with x=0.108 and x=0.127, in the overdoped range of the doping phase diagram, characterized by notable modulation of the superconducting gap. Heavy ion irradiation with matching field doses of 6 T and 6.5 T respectively, were used to create columnar defects and to study their effect on the temperature Δλ(T). The variation of the low-temperature penetration depth in both pristine and irradiated samples was fitted with a power-law function Δλ(T) = ATn. Irradiation increases the magnitude of the pre-factor A and decreases the exponent n, similar to the effect on the optimally doped samples. This finding supports the universal s ± scenario for the whole doping range.

  15. Design Study: Rocket Based MHD Generator

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This report addresses the technical feasibility and design of a rocket based MHD generator using a sub-scale LOx/RP rocket motor. The design study was constrained by assuming the generator must function within the performance and structural limits of an existing magnet and by assuming realistic limits on (1) the axial electric field, (2) the Hall parameter, (3) current density, and (4) heat flux (given the criteria of heat sink operation). The major results of the work are summarized as follows: (1) A Faraday type of generator with rectangular cross section is designed to operate with a combustor pressure of 300 psi. Based on a magnetic field strength of 1.5 Tesla, the electrical power output from this generator is estimated to be 54.2 KW with potassium seed (weight fraction 3.74%) and 92 KW with cesium seed (weight fraction 9.66%). The former corresponds to a enthalpy extraction ratio of 2.36% while that for the latter is 4.16%; (2) A conceptual design of the Faraday MHD channel is proposed, based on a maximum operating time of 10 to 15 seconds. This concept utilizes a phenolic back wall for inserting the electrodes and inter-electrode insulators. Copper electrode and aluminum oxide insulator are suggested for this channel; and (3) A testing configuration for the sub-scale rocket based MHD system is proposed. An estimate of performance of an ideal rocket based MHD accelerator is performed. With a current density constraint of 5 Amps/cm(exp 2) and a conductivity of 30 Siemens/m, the push power density can be 250, 431, and 750 MW/m(sup 3) when the induced voltage uB have values of 5, 10, and 15 KV/m, respectively.

  16. Structural studies of Hollandite based radioactive wasteformd

    NASA Astrophysics Data System (ADS)

    Whittle, K. R.; Maddrell, E. R.; Ashbrook, S. E.; Sartbaeva, A.; Attfield, J. P.; Dove, M. T.; Farnan, I.; Redfern, S. A. T.

    2003-04-01

    Materials based on the hollandite-type structure, Ba1.2-xCs_x(Al,Mg,Ti)_8O16 (x=0,0.1,0.25) have been studied as a basis for 135Cs and 137Cs active waste immobilisation. Powders have been prepared using a modified 2-stage isopropoxide-gel route. The samples have been consolidated using both Hot Isostatic Pressing (HIP) and Cold Uniaxial Pressing prior to sintering.. The structures of these materials have been determined using X-ray diffraction techniques, and Magic-Angle Spinning Nuclear Magnetic Resonance (MAS-NMR). Dielectric spectroscopy has been measured for these systems to determine mobility of the Cs^+ ion in the structure. The structural data is compared for both pressing techniques and by direct comparison with the pseudo-amorphous precursor. The dielectric spectroscopy data has been collected for the pressed and fired samples.

  17. Ground Based Studies of the Outer Planets

    NASA Technical Reports Server (NTRS)

    Trafton, Laurence M.

    2005-01-01

    This report covers progress to date under this grant on our continuing program to conduct ground based studies of the outer solar system planets and satellites, with emphasis on spectroscopy and atmospheric phenomena. The research continues under our new PAST grant, NNG04G131G beginning 5/1/2004. The original period of performance of the subject grant was 3/1/2001 to 2/28/2004, but was extended one year at no cost. Although there is some overlap in the scientific projects conducted during the extended year with those of the new grant, this report is confined to the portion of the work funded under NAG5-10435. The primary goals for this grant period were a comparative study of outer planet thermospheres/ionospheres near solar maximum, extended to the mid-IR, and the investigation of molecular dimers in outer solar system atmospheres. This project supports NASA's planned space missions, Jupiter Polar Orbiter, outer Planet Microprobes, and the recent Cassini flyby of Jupiter. It also supports the OSS strategic plan themes, The Exploration of the Solar System and The Sun-Earth Connection/ Understanding comparative planetary space environments.

  18. Laminar Diffusion Flame Studies (Ground- and Space-Based Studies)

    NASA Technical Reports Server (NTRS)

    Dai, Z.; El-Leathy, A. M.; Lin, K.-C.; Sunderland, P. B.; Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2000-01-01

    Laminar diffusion flames are of interest because they provide model flame systems that are far more tractable for analysis and experiments than more practical turbulent diffusion flames. Certainly, understanding flame processes within laminar diffusion flames must precede understanding these processes in more complex turbulent diffusion flames. In addition, many properties of laminar diffusion flames are directly relevant to turbulent diffusion flames using laminar flamelet concepts. Laminar jet diffusion flame shapes (luminous flame boundaries) have been of particular interest since the classical study of Burke and Schumann because they are a simple nonintrusive measurement that is convenient for evaluating flame structure predictions. Thus, consideration of laminar flame shapes is undertaken in the following, emphasizing conditions where effects of gravity are small, due to the importance of such conditions to practical applications. Another class of interesting properties of laminar diffusion flames are their laminar soot and smoke point properties (i.e., the flame length, fuel flow rate, characteristic residence time, etc., at the onset of soot appearance in the flame (the soot point) and the onset of soot emissions from the flame (the smoke point)). These are useful observable soot properties of nonpremixed flames because they provide a convenient means to rate several aspects of flame sooting properties: the relative propensity of various fuels to produce soot in flames; the relative effects of fuel structure, fuel dilution, flame temperature and ambient pressure on the soot appearance and emission properties of flames; the relative levels of continuum radiation from soot in flames; and effects of the intrusion of gravity (or buoyant motion) on emissions of soot from flames. An important motivation to define conditions for soot emissions is that observations of laminar jet diffusion flames in critical environments, e.g., space shuttle and space station

  19. Lunar Base Thermoelectric Power Station Study

    SciTech Connect

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, Gerhard; Brooks, Michael; Heshmatpour, Ben

    2006-01-20

    Under NASA's Project Prometheus, the Nuclear Space Power Systems Program, the Jet Propulsion Laboratory, Pratt and Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) Task, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing, and promising candidates for the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as a lunar base power station where kilowatts of power would be required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this particular mission concept. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed as well as transport issues for this concept. The goal of the study was to review the entire life cycle of

  20. Lunar base thermoelectric power station study

    NASA Technical Reports Server (NTRS)

    Determan, William; Frye, Patrick; Mondt, Jack; Fleurial, Jean-Pierre; Johnson, Ken; Stapfer, G.; Brooks, Michael D.; Heshmatpour, Ben

    2006-01-01

    Under NASA's Project Prometheus, the Nuclear Systems Program, the Jet Propulsion Laboratory, Pratt & Whitney Rocketdyne, and Teledyne Energy Systems have teamed with a number of universities, under the Segmented Thermoelectric Multicouple Converter (STMC) program, to develop the next generation of advanced thermoelectric converters for space reactor power systems. Work on the STMC converter assembly has progressed to the point where the lower temperature stage of the segmented multicouple converter assembly is ready for laboratory testing and the upper stage materials have been identified and their properties are being characterized. One aspect of the program involves mission application studies to help define the potential benefits from the use of these STMC technologies for designated NASA missions such as the lunar base power station where kilowatts of power are required to maintain a permanent manned presence on the surface of the moon. A modular 50 kWe thermoelectric power station concept was developed to address a specific set of requirements developed for this mission. Previous lunar lander concepts had proposed the use of lunar regolith as in-situ radiation shielding material for a reactor power station with a one kilometer exclusion zone radius to minimize astronaut radiation dose rate levels. In the present concept, we will examine the benefits and requirements for a hermetically-sealed reactor thermoelectric power station module suspended within a man-made lunar surface cavity. The concept appears to maximize the shielding capabilities of the lunar regolith while minimizing its handling requirements. Both thermal and nuclear radiation levels from operation of the station, at its 100-m exclusion zone radius, were evaluated and found to be acceptable. Site preparation activities are reviewed and well as transport issues for this concept. The goal of the study was to review the entire life cycle of the unit to assess its technical problems and technology

  1. Longitudinal studies based on vital registration records.

    PubMed

    Fox, A J

    1989-01-01

    We describe here the increased use of routine vital event and census records to construct national follow-up and longitudinal studies. The strengths and weaknesses of these studies are discussed and examples given of their use in research into relationships between employment and mortality and socio-economic differences in mortality. PMID:2626588

  2. Studies of anisotropy of iron based superconductors

    SciTech Connect

    Murphy, Jason

    2013-01-01

    To study the electronic anisotropy in iron based superconductors, the temperature dependent London penetration depth, Δλ (T), have been measured in several compounds, along with the angular dependent upper critical field, Hc2(T). Study was undertaken on single crystals of Ba(Fe1-xCox)2As2 with x=0.108 and x=0.127, in the overdoped range of the doping phase diagram, characterized by notable modulation of the superconducting gap. Heavy ion irradiation with matching field doses of 6 T and 6.5 T respectively, were used to create columnar defects and to study their effect on the temperature Δλ (T). The variation of the low-temperature penetration depth in both pristine and irradiated samples was fitted with a power-law function Δλ (T) = ATn. Irradiation increases the magnitude of the pre-factor A and decreases the exponent n, similar to the effect on the optimally doped samples. This finding supports the universal s± scenario for the whole doping range. Knowing that the s± gap symmetry exists across the superconducting dome for the electron doped systems, we next looked at λ (T), in optimally - doped, SrFe2(As1-xPx)2, x =0.35. Both, as-grown (Tc ~ 25 K) and annealed (Tc ~ 35 K) single crystals of SrFe2(As1-xPx)2 were measured. Annealing decreases the absolute value of the London penetration depth from λ(0) = 300 ± 10 nm in as-grown samples to λ (0) = 275±10 nm. At low temperatures, λ (T) ~ T indicates a superconducting gap with line nodes. Analysis of the full-temperature range superfluid density is consistent with the line nodes, but differs from the simple single-gap d-wave. The observed behavior is very similar to that of BaFe2(As1-xPx)2, showing that isovalently substituted pnictides are inherently different from

  3. Studies in target-based treatment.

    PubMed

    Kurzrock, Razelle

    2007-05-01

    In this issue, Molecular Cancer Therapeutics inaugurates a new feature-The Cutting Edge: Spotlight on Clinical Response-whose objective is the rapid publication of breaking discoveries regarding target- or mechanism-based clinical responses in cancer. Targeted molecules are poised to alter the landscape of clinical cancer treatment. For example, because they can distinguish cancer cells from their normal counterparts, agents such as imatinib mesylate, a Bcr-Abl and Kit kinase inhibitor, can result in remarkable responses with minimal host toxicity in patients suffering from diseases characterized by abnormalities in the targeted kinases. Indeed, studies of imatinib mesylate in early-stage chronic myelogenous leukemia, whose hallmark is the aberrant Bcr-Abl, show response rates of more than 90%. Furthermore, gastrointestinal stromal tumors (GIST), a notoriously chemotherapy-refractory sarcoma, characterized by activating Kit kinase mutations, can show dramatic metabolic responses within days after initiation of treatment. With the wealth of new knowledge in this field, and numerous novel targeted molecules entering clinical trials, the above examples are likely to represent the tip of the iceberg. Indeed, in this issue, a paper by Senzer et al. documents, for the first time, successful use of adenoviral p53 therapy to treat a tumor in a patient with Li Fraumeni Syndrome, a hereditary cancer syndrome caused by the mutation of the p53 tumor suppressor gene. Some of the features of this response, such as the early disappearance of metabolic activity on fluorodeoxyglucose-positron emission tomography scans, are reminiscent of those of GIST responses to imatinib. These findings have important implications for patients with this syndrome, who are prone to develop numerous tumors and often succumb at a young age. In addition, because mutations in p53 are one of the more common aberrations in cancer in general, identification of these mutations and exploration of this

  4. Study of wheat protein based materials

    NASA Astrophysics Data System (ADS)

    Ye, Peng

    Wheat gluten is a naturally occurring protein polymer. It is produced in abundance by the agricultural industry, is biodegradable and very inexpensive (less than $0.50/lb). It has unique viscoelastic properties, which makes it a promising alternative to synthetic plastics. The unplasticized wheat gluten is, however, brittle. Plasticizers such as glycerol are commonly used to give flexibility to the articles made of wheat gluten but with the penalty of greatly reduced stiffness. Former work showed that the brittleness of wheat gluten can also be improved by modifying it with a tri-thiol additive with no penalty of reduced stiffness. However, the cost of the customer designed tri-thiol additive was very high and it was unlikely to make a cost effective material from such an expensive additive. Here we designed a new, inexpensive thiol additive called SHPVA. It was synthesized from polyvinyl alcohol (PVA) through a simple esterification reaction. The mechanical data of the molded wheat gluten/SHPVA material indicated that wheat gluten was toughened by SHPVA. As a control, the wheat gluten/PVA material showed no improvement compared with wheat gluten itself. Several techniques have been used to characterize this novel protein/polymer blend. Differential scanning calorimetric (DSC) study showed two phases in both wheat gluten/PVA and wheat gluten/SHPVA material. However, scanning electron microscope (SEM) pictures indicated that PVA was macroscopically separated from wheat gluten, while wheat gluten/SHPVA had a homogeneous look. The phase image from the atomic force microscope (AFM) gave interesting contrast based on the difference in the mechanical properties of these two phases. The biodegradation behavior of these protein/polymer blends was examined in soil. SHPVA was not degraded in the time period of the experiment. Wheat gluten/SHPVA degraded slower than wheat gluten. We also developed some other interesting material systems based on wheat gluten, including the

  5. Viscosity studies of water based magnetite nanofluids

    NASA Astrophysics Data System (ADS)

    Anu, K.; Hemalatha, J.

    2016-05-01

    Magnetite nanofluids of various concentrations have been synthesized through co-precipitation method. The structural and topographical studies made with the X-Ray Diffractometer and Atomic Force Microscope are presented in this paper. The density and viscosity studies for the ferrofluids of various concentrations have been made at room temperature. The experimental viscosities are compared with theoretical values obtained from Einstein, Batchelor and Wang models. An attempt to modify the Rosensweig model is made and the modified Rosensweig equation is reported. In addition, new empirical correlation is also proposed for predicting viscosity of ferrofluid at various concentrations.

  6. Conductivity study of chitosan based nanocomposites

    NASA Astrophysics Data System (ADS)

    Mohan, C. Raja; Murugan, S.; Jayakumar, K.

    2012-06-01

    Bio polymer like chitosan is dissolved in acids like formic and acetic acid and CdS nano particle prepared by chemical methods has been embedded in the salts of chitosan matrix. The viscous solution is cast into film on the glass substrate using spin coating method and their ionic conductivity has been studied for various frequencies and temperatures.

  7. Adrenocorticotrophic Hormone Levels in Ground Based Studies

    NASA Technical Reports Server (NTRS)

    Campbell, B. O.

    1972-01-01

    Baseline values of immunoreactive ACTH were established in the normal healthy adult. Normal levels of ACTH secretion were determined for both the male and the female in circulating plasma and serum. The data obtained in these studies are particularly significant in that the sampling was carefully controlled; only healthy employed individuals of both sexes were tested in a routine work situation that would not be considered conducive to stress. It has been found that alterations in the classically described circadian rhythm of ACTH secretion can occur when activities (such as work/rest cycles) are imposed on the individual studied. These changes can be demonstrated even when there is no appreciable change noted in the rhythm of hydrocortisone secretion.

  8. Studies on recycled aggregates-based concrete.

    PubMed

    Rakshvir, Major; Barai, Sudhirkumar V

    2006-06-01

    Reduced extraction of raw materials, reduced transportation cost, improved profits, reduced environmental impact and fast-depleting reserves of conventional natural aggregates has necessitated the use of recycling, in order to be able to conserve conventional natural aggregate. In this study various physical and mechanical properties of recycled concrete aggregates were examined. Recycled concrete aggregates are different from natural aggregates and concrete made from them has specific properties. The percentages of recycled concrete aggregates were varied and it was observed that properties such as compressive strength showed a decrease of up to 10% as the percentage of recycled concrete aggregates increased. Water absorption of recycled aggregates was found to be greater than natural aggregates, and this needs to be compensated during mix design.

  9. Epidemiologic studies based on the Chernobyl accident

    SciTech Connect

    Beebe, G.

    1996-12-31

    There are great opportunities in the post-Chernobyl experience for significant epidemiologic research, perhaps even more in the area of disaster research than in the area of the human health effects of ionizing radiation. But the potential opportunity for learning the effects of radioiodine on the thyroid is very great and has aroused widespread national and international investigative interest. The opportunities for significant epidemiologic research are, however, severely limited currently by the worsening economic situation in Belarus and Ukraine, where the greatest exposure occurred, and by the lack of personnel trained in appropriate methods of study, the lack of modern equipment, the lack of supplies, the poor communication facilities, and the difficulties of accurate dose estimation. the disadvantages may or may not outweigh the obvious advantages of large numbers, the extensive direct thyroidal measurements made shortly after the accident in 1986, the magnitude of the releases of radioiodine, and the retention of the former Soviet system of universal medical care. Both the European Commission (EC) and the World Health Organization (WHO) have been working actively to strengthen the infrastructure of Russia, Belarus, and Ukraine. New scientific knowledge has yet to emerge from the extensive epidemiologic work but information of considerable public health significance has begun to accumulate. The bulk of the thyroid cancer has been shown to be valid by international pathology review; both EC and WHO representatives have declared the increase in thyroid cancer among children to have been caused in large part by Chernobyl. No increase in leukemia has been seen in the general population. The WHO pilot studies have shown no evidence of an increase in psychologic or neurologic complications among those exposed in utero. Ongoing epidemiologic work can be described by review of the inventory that the WHO has begun to maintain and publish. 20 refs., 7 tabs.

  10. Contrail study with ground-based cameras

    NASA Astrophysics Data System (ADS)

    Schumann, U.; Hempel, R.; Flentje, H.; Garhammer, M.; Graf, K.; Kox, S.; Lösslein, H.; Mayer, B.

    2013-08-01

    Photogrammetric methods and analysis results for contrails observed with wide-angle cameras are described. Four cameras of two different types (view angle < 90° or whole-sky imager) at the ground at various positions are used to track contrails and to derive their altitude, width, and horizontal speed. Camera models for both types are described to derive the observation angles for given image coordinates and their inverse. The models are calibrated with sightings of the Sun, the Moon and a few bright stars. The methods are applied and tested in a case study. Four persistent contrails crossing each other together with a short-lived one are observed with the cameras. Vertical and horizontal positions of the contrails are determined from the camera images to an accuracy of better than 200 m and horizontal speed to 0.2 m s-1. With this information, the aircraft causing the contrails are identified by comparison to traffic waypoint data. The observations are compared with synthetic camera pictures of contrails simulated with the contrail prediction model CoCiP, a Lagrangian model using air traffic movement data and numerical weather prediction (NWP) data as input. The results provide tests for the NWP and contrail models. The cameras show spreading and thickening contrails suggesting ice-supersaturation in the ambient air. The ice-supersaturated layer is found thicker and more humid in this case than predicted by the NWP model used. The simulated and observed contrail positions agree up to differences caused by uncertain wind data. The contrail widths, which depend on wake vortex spreading, ambient shear and turbulence, were partly wider than simulated.

  11. Contrail study with ground-based cameras

    NASA Astrophysics Data System (ADS)

    Schumann, U.; Hempel, R.; Flentje, H.; Garhammer, M.; Graf, K.; Kox, S.; Lösslein, H.; Mayer, B.

    2013-12-01

    Photogrammetric methods and analysis results for contrails observed with wide-angle cameras are described. Four cameras of two different types (view angle < 90° or whole-sky imager) at the ground at various positions are used to track contrails and to derive their altitude, width, and horizontal speed. Camera models for both types are described to derive the observation angles for given image coordinates and their inverse. The models are calibrated with sightings of the Sun, the Moon and a few bright stars. The methods are applied and tested in a case study. Four persistent contrails crossing each other, together with a short-lived one, are observed with the cameras. Vertical and horizontal positions of the contrails are determined from the camera images to an accuracy of better than 230 m and horizontal speed to 0.2 m s-1. With this information, the aircraft causing the contrails are identified by comparison to traffic waypoint data. The observations are compared with synthetic camera pictures of contrails simulated with the contrail prediction model CoCiP, a Lagrangian model using air traffic movement data and numerical weather prediction (NWP) data as input. The results provide tests for the NWP and contrail models. The cameras show spreading and thickening contrails, suggesting ice-supersaturation in the ambient air. The ice-supersaturated layer is found thicker and more humid in this case than predicted by the NWP model used. The simulated and observed contrail positions agree up to differences caused by uncertain wind data. The contrail widths, which depend on wake vortex spreading, ambient shear and turbulence, were partly wider than simulated.

  12. 30 WS North Base Wind Study

    NASA Technical Reports Server (NTRS)

    Wheeler, Mark

    2011-01-01

    The 30 Weather Squadron (30 WS) is concerned about strong winds observed at their northern towers without advance warning. They state that terrain influences along the extreme northern fringes of Vandenberg Air Force Base (VAFB) make it difficult for forecasters to issue timely and accurate high wind warnings for northeasterly wind events. These events tend to occur during the winter or early spring when they are under the influence of the Great Basin high pressure weather regime. The Launch Weather Officers (LWOs) have seen these rapid wind increases in the current northern Towers 60, 70 and 71 in excess of their 35 kt operational warning threshold. For this task, the 30 WS requested the Applied Meteorology Unit (AMU) analyze data from days when these towers reported winds in excess of 35 kt and determine if there were any precursors in the observations that would allow the LWOs to better forecast and warn their operational customers for these wind events. The 30 WS provided wind tower data for the cool season (October - March) from the period January 2004-March 20 IO. The AMU decoded and evaluated the wind tower data for 66 days identified by the 30 WS as having high-wind events. Out of the 66 event days, only 30 had wind speed observations of > or =35 kt from at least one of the three northern towers. The AMU analyzed surface and upper air charts to determine the synoptic conditions for each event day along with tower peak wind speed and direction time series and wind rose charts for all 30 event days. The analysis revealed a trend on all event days in which the tower winds shifted to the northeast for a period of time before the first recorded > or =35 kt wind speed. The time periods for the 30 event days ranged from 20 minutes to several hours, with a median value of 110 minutes. This trend, if monitored, could give the 30 WS forecasters a precursor to assist in issuing an operational warning before a high wind event occurs. The AMU recommends developing a

  13. Subdural haemorrhages in infants: population based study

    PubMed Central

    Jayawant, S; Rawlinson, A; Gibbon, F; Price, J; Schulte, J; Sharples, P; Sibert, J R; Kemp, A M

    1998-01-01

    Objectives To identify the incidence, clinical outcome, and associated factors of subdural haemorrhage in children under 2 years of age, and to determine how such cases were investigated and how many were due to child abuse. Design Population based case series. Setting South Wales and south west England. Subjects Children under 2 years of age who had a subdural haemorrhage. We excluded neonates who developed subdural haemorrhage during their stay on a neonatal unit and infants who developed a subdural haemorrhage after infection or neurosurgical intervention. Main outcome measures Incidence and clinical outcome of subdural haemorrhage in infants, the number of cases caused by child abuse, the investigations such children received, and associated risk factors. Results Thirty three children (23 boys and 10 girls) were identified with subdural haemorrhage. The incidence was 12.8/100 000 children/year (95% confidence interval 5.4 to 20.2). Twenty eight cases (85%) were under 1 year of age. The incidence of subdural haemorrhage in children under 1 year of age was 21.0/100 000 children/year and was therefore higher than in the older children. The clinical outcome was poor: nine infants died and 15 had profound disability. Only 22 infants had the basic investigations of a full blood count, coagulation screen, computed tomography or magnetic resonance imaging, skeletal survey or bone scan, and ophthalmological examination. In retrospect, 27 cases (82%) were highly suggestive of abuse. Conclusion Subdural haemorrhage is common in infancy and carries a poor prognosis; three quarters of such infants die or have profound disability. Most cases are due to child abuse, but in a few the cause is unknown. Some children with subdural haemorrhage do not undergo appropriate investigations. We believe the clinical investigation of such children should include a full multidisciplinary social assessment, an ophthalmic examination, a skeletal survey supplemented with a bone scan or a

  14. DNA-Based Vaccine Guards Against Zika in Monkey Study

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_161106.html DNA-Based Vaccine Guards Against Zika in Monkey Study ... THURSDAY, Sept. 22, 2016 (HealthDay News) -- An experimental DNA-based vaccine protected monkeys from infection with the ...

  15. StudySearch: a web-based application for posting and searching clinical research studies.

    PubMed

    Gonsenhauser, Blair; Hallarn, Rose; Carpenter, Daniel; Para, Michael F; Reider, Carson R

    2016-03-01

    Participant accrual into research studies is critical to advancing clinical and translational research to clinical care. Without sufficient recruitment, the purpose of any research study cannot be realized; yet, low recruitment and enrollment of participants persist. StudySearch is a web-based application designed to provide an easily readable, publicly accessible, and searchable listing of IRB-approved protocols that are accruing study participants. The Regulatory, Recruitment and Biomedical Informatics Cores of the Center for Clinical and Translational Science (CCTS) at The Ohio State University developed this research study posting platform. Postings include basic descriptive information: study title, purpose of the study, eligibility criteria and study personnel contact information. Language concerning benefits and/or inducements is not included; therefore, while IRB approval for a study to be listed on StudySearch is required, IRB approval of the posted language is not. Studies are listed by one of two methods; one automated and one manual: (1). Studies registered on ClinicalTrials.gov are automatically downloaded once a month; or (2). Studies are submitted directly by researchers to the CCTS Regulatory Core staff. In either case, final language is a result of an iterative process between researchers and CCTS staff. Deployed in January 2011 at OSU, this application has grown to approximately 200 studies currently posted and 1500 unique visitors per month. Locally, StudySearch is part of the CCTS recruitment toolkit. Features continue to be modified to better accommodate user behaviors. Nationally, this open source application is available for use.

  16. Space station accommodations for lunar base elements: A study

    NASA Technical Reports Server (NTRS)

    Weidman, Deene J.; Cirillo, William; Llewellyn, Charles; Kaszubowski, Martin; Kienlen, E. Michael, Jr.

    1987-01-01

    The results of a study conducted at NASA-LaRC to assess the impact on the space station of accommodating a Manned Lunar Base are documented. Included in the study are assembly activities for all infrastructure components, resupply and operations support for lunar base elements, crew activity requirements, the effect of lunar activities on Cape Kennedy operations, and the effect on space station science missions. Technology needs to prepare for such missions are also defined. Results of the study indicate that the space station can support the manned lunar base missions with the addition of a Fuel Depot Facility and a heavy lift launch vehicle to support the large launch requirements.

  17. A Science-Based Generalist Degree: Science with Industrial Studies.

    ERIC Educational Resources Information Center

    Leach, Donald

    1978-01-01

    Napier College offers a degree program that is science-based, but that includes courses in industrial studies and the social sciences within industrial studies. The aim and structure of the program, an outline of the curriculum, and the entering qualifications and employment prospects of the students are discussed. (JMD)

  18. INTEGRATED GENOME-BASED STUDIES OF SHEWANELLA ECOPHYSIOLOGY

    SciTech Connect

    TIEDJE, JAMES M; KONSTANTINIDIS, KOSTAS; WORDEN, MARK

    2014-01-08

    The aim of the work reported is to study Shewanella population genomics, and to understand the evolution, ecophysiology, and speciation of Shewanella. The tasks supporting this aim are: to study genetic and ecophysiological bases defining the core and diversification of Shewanella species; to determine gene content patterns along redox gradients; and to Investigate the evolutionary processes, patterns and mechanisms of Shewanella.

  19. Arts-Based Learning and Leadership Development: A Case Study

    ERIC Educational Resources Information Center

    Brenner, Michael Yoel

    2010-01-01

    This qualitative case study was designed to explore how participants in an arts-based leadership development program learned to draw on their right brain capabilities in order to develop the creative competencies required to solve complex modern-day problems in new and different ways. The rationale for this study emerges from the researcher's…

  20. StudySearch: a web-based application for posting and searching clinical research studies.

    PubMed

    Gonsenhauser, Blair; Hallarn, Rose; Carpenter, Daniel; Para, Michael F; Reider, Carson R

    2016-03-01

    Participant accrual into research studies is critical to advancing clinical and translational research to clinical care. Without sufficient recruitment, the purpose of any research study cannot be realized; yet, low recruitment and enrollment of participants persist. StudySearch is a web-based application designed to provide an easily readable, publicly accessible, and searchable listing of IRB-approved protocols that are accruing study participants. The Regulatory, Recruitment and Biomedical Informatics Cores of the Center for Clinical and Translational Science (CCTS) at The Ohio State University developed this research study posting platform. Postings include basic descriptive information: study title, purpose of the study, eligibility criteria and study personnel contact information. Language concerning benefits and/or inducements is not included; therefore, while IRB approval for a study to be listed on StudySearch is required, IRB approval of the posted language is not. Studies are listed by one of two methods; one automated and one manual: (1). Studies registered on ClinicalTrials.gov are automatically downloaded once a month; or (2). Studies are submitted directly by researchers to the CCTS Regulatory Core staff. In either case, final language is a result of an iterative process between researchers and CCTS staff. Deployed in January 2011 at OSU, this application has grown to approximately 200 studies currently posted and 1500 unique visitors per month. Locally, StudySearch is part of the CCTS recruitment toolkit. Features continue to be modified to better accommodate user behaviors. Nationally, this open source application is available for use. PMID:26912012

  1. StudySearch: a web-based application for posting and searching clinical research studies

    PubMed Central

    Gonsenhauser, Blair; Hallarn, Rose; Carpenter, Daniel; Para, Michael F; Reider, Carson R

    2016-01-01

    Participant accrual into research studies is critical to advancing clinical and translational research to clinical care. Without sufficient recruitment, the purpose of any research study cannot be realized; yet, low recruitment and enrollment of participants persist. StudySearch is a web-based application designed to provide an easily readable, publicly accessible, and searchable listing of IRB-approved protocols that are accruing study participants. The Regulatory, Recruitment and Biomedical Informatics Cores of the Center for Clinical and Translational Science (CCTS) at The Ohio State University developed this research study posting platform. Postings include basic descriptive information: study title, purpose of the study, eligibility criteria and study personnel contact information. Language concerning benefits and/or inducements is not included; therefore, while IRB approval for a study to be listed on StudySearch is required, IRB approval of the posted language is not. Studies are listed by one of two methods; one automated and one manual: (1). Studies registered on ClinicalTrials.gov are automatically downloaded once a month; or (2). Studies are submitted directly by researchers to the CCTS Regulatory Core staff. In either case, final language is a result of an iterative process between researchers and CCTS staff. Deployed in January 2011 at OSU, this application has grown to approximately 200 studies currently posted and 1500 unique visitors per month. Locally, StudySearch is part of the CCTS recruitment toolkit. Features continue to be modified to better accommodate user behaviors. Nationally, this open source application is available for use. PMID:26912012

  2. The Inclusion of African-American Study Participants in Web-Based Research Studies: Viewpoint

    PubMed Central

    Harker, Laura; Arriola, Kimberly R. Jacob

    2016-01-01

    The use of Web-based methods for research recruitment and intervention delivery has greatly increased as Internet usage continues to grow. These Internet-based strategies allow for researchers to quickly reach more people. African-Americans are underrepresented in health research studies. Due to this, African-Americans get less benefit from important research that could address the disproportionate health outcomes they face. Web-based research studies are one promising way to engage more African-Americans and build trust with the African-American community. With African-Americans’ increasing access to the Internet using mobile phones and other mobile phone technologies, we advocate for efforts to increase the representation of African-Americans in research studies by using the Internet as a recruitment tool and conclude with recommendations that support this goal. PMID:27334683

  3. The Inclusion of African-American Study Participants in Web-Based Research Studies: Viewpoint.

    PubMed

    Watson, Bekeela; Robinson, Dana H Z; Harker, Laura; Arriola, Kimberly R Jacob

    2016-01-01

    The use of Web-based methods for research recruitment and intervention delivery has greatly increased as Internet usage continues to grow. These Internet-based strategies allow for researchers to quickly reach more people. African-Americans are underrepresented in health research studies. Due to this, African-Americans get less benefit from important research that could address the disproportionate health outcomes they face. Web-based research studies are one promising way to engage more African-Americans and build trust with the African-American community. With African-Americans' increasing access to the Internet using mobile phones and other mobile phone technologies, we advocate for efforts to increase the representation of African-Americans in research studies by using the Internet as a recruitment tool and conclude with recommendations that support this goal. PMID:27334683

  4. Image based 3D city modeling : Comparative study

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  5. [Evidence-based medicine and real world study in clinical study of acupuncture and moxibustion].

    PubMed

    Cai, Ronglin; Hu, Ling; Wu, Zijian

    2015-09-01

    Evidence-based medicine (EBM) has been widely applied in clinical study of acupuncture and moxibustion, and the real-world study (RWS) has gradually become an important way of clinical research in the world in recent years. It is worthy of our in-depth study and discussion that how to evaluate the advantages and limitations of EBM and RWS as well as their reasonable application in clinical study of acupuncture and moxibustion. The characteristics and difference between RWS and EBM, and the situation of acupuncture clinical research methods are discussed in this paper. It is proposed that we should understand the advantages of RWS in acupuncture clinical research, fully realize the limitations of EBM and RWS, recognize the complexity and particularity of RWS, and apply EBM and RWS into acupuncture clinical research. Meanwhile acupuncture clinical manipulation standardization should be further promoted, which is benefit to develop clinical study, improve clinical efficacy and promote the popularization of acupuncture and moxibustion.

  6. Review of genotoxicity biomonitoring studies of glyphosate-based formulations.

    PubMed

    Kier, Larry D

    2015-03-01

    Abstract Human and environmental genotoxicity biomonitoring studies involving exposure to glyphosate-based formulations (GBFs) were reviewed to complement an earlier review of experimental genotoxicity studies of glyphosate and GBFs. The environmental and most of the human biomonitoring studies were not informative because there was either a very low frequency of GBF exposure or exposure to a large number of pesticides without analysis of specific pesticide effects. One pesticide sprayer biomonitoring study indicated there was not a statistically significant relationship between frequency of GBF exposure reported for the last spraying season and oxidative DNA damage. There were three studies of human populations in regions of GBF aerial spraying. One study found increases for the cytokinesis-block micronucleus endpoint but these increases did not show statistically significant associations with self-reported spray exposure and were not consistent with application rates. A second study found increases for the blood cell comet endpoint at high exposures causing toxicity. However, a follow-up to this study 2 years after spraying did not indicate chromosomal effects. The results of the biomonitoring studies do not contradict an earlier conclusion derived from experimental genotoxicity studies that typical GBFs do not appear to present significant genotoxic risk under normal conditions of human or environmental exposures.

  7. Problem-Based Learning: Case Studies, Experience and Practice. Case Studies of Teaching in Higher Education.

    ERIC Educational Resources Information Center

    Schwartz, Peter, Ed.; Mennin, Stewart, Ed.; Webb, Graham, Ed.

    The case studies in this book consider many of the most important issues perceived and experienced by people who are using or developing problem-based learning (PBL). The book focuses on politics, administration, resources, the roles of teachers, and the effects of PBL on students. The chapters are: (1) "Come and See the Real Thing" (David…

  8. Multi-baseline IFSAR study using an SBR based simulator

    NASA Astrophysics Data System (ADS)

    Bhalla, Rajan; Ling, Hao

    2005-05-01

    This paper describes the results of a multi-baseline IFSAR study using a shooting and bouncing ray (SBR) based IFSAR simulator. The SBR technique has been used in the past for 2-D SAR and IFSAR simulations. This paper extends on those approaches for modeling multi-baseline IFSAR images. IFSAR gives the height estimate for a target and hence leads to a 3-D image of the target. The 3-D reconstruction is dependent on the choice of IFSAR sensor parameters. We present a tradeoff study the sensor resolution versus the number of baselines using the SBR based simulator.

  9. A population-based cohort study of oral health in South Brazil: The Porto Alegre Study.

    PubMed

    Haas, Alex Nogueira; Gaio, Eduardo José; Wagner, Marcius Comparsi; Rios, Fernando Silva; Costa, Ricardo dos Santos Araujo; Rösing, Cassiano Kuchenbecker; Oppermann, Rui Vicente; Albandar, Jasim; Susin, Cristiano

    2015-01-01

    Few population-based cohort studies have been established in Dentistry and this is especially true for Latin America. We conducted a population-based prospective study focusing on oral health in Porto Alegre, south Brazil, and herein we describe its methodology and discuss directions for further research. The cohort was established in 2001 using a multistage probability sample of 1,465 toothed and 121 edentulous subjects. A 5-year follow-up was performed in 2006 that included 755 individuals. The main aim of this study was to determine the pattern and risk factors for periodontal disease progression and tooth loss incidence. A full-mouth protocol was used including periodontal assessments at six sites per tooth. Primary outcomes were periodontal attachment loss and tooth loss. Oral mucosal lesions, dental plaque, gingivitis, supragingival calculus, probing depths, gingival recession, and dental caries were also assessed. This is the first population-based cohort study to focus on periodontal disease in Latin America. Findings will contribute to our understanding of the epidemiology of periodontal disease and provide valuable data for the planning and implementation of preventive and therapeutic strategies. PMID:26083520

  10. Computer-Based Information Services in Medicine: A Feasibility Study.

    ERIC Educational Resources Information Center

    Cox, P. H.; And Others

    The objectives of this study were to examine the need and potential demand for computer-based information services in the University of Otago medical libraries, to evaluate the various databases of interest, and to recommend the best means of access to such services. Data were collected through user and library surveys, an extensive literature…

  11. A Usability Study of Interactive Web-Based Modules

    ERIC Educational Resources Information Center

    Girard, Tulay; Pinar, Musa

    2011-01-01

    This research advances the understanding of the usability of marketing case study modules in the area of interactive web-based technologies through the assignment of seven interactive case modules in a Principles of Marketing course. The case modules were provided for marketing students by the publisher, McGraw Hill Irwin, of the "Marketing"…

  12. Project-Based Learning in Electronic Technology: A Case Study

    ERIC Educational Resources Information Center

    Li, Li

    2015-01-01

    A case study of project-based learning (PBL) implemented in Tianjin University of Technology and Education is presented. This multidiscipline project is innovated to meet the novel requirements of industry while keeping its traditional effectiveness in driving students to apply knowledge to practice and problem-solving. The implementation of PBL…

  13. Science-Based Business Studies at Leiden University

    ERIC Educational Resources Information Center

    Jousma, Harmen

    2006-01-01

    The Science Based Business (SBB) programme was established at Leiden University in 2001 in an effort to counter the unidirectional professionalism of students in science studies--not explicitly to meet the needs of business and industry. Nor is SBB a stand-alone Master's programme like the MS/MBA or the PSM in the USA: rather, it is designed to be…

  14. [The study of noninvasive ventilator impeller based on ANSYS].

    PubMed

    Hu, Zhaoyan; Lu, Pan; Xie, Haiming; Zhou, Yaxu

    2011-06-01

    An impeller plays a significant role in the non-invasive ventilator. This paper shows a model of impeller for noninvasive ventilator established with the software Solidworks. The model was studied for feasibility based on ANSYS. Then stress and strain of the impeller were discussed under the external loads. The results of the analysis provided verification for the reliable design of impellers.

  15. A Multidisciplinary Osteoporosis Service-Based Action Research Study

    ERIC Educational Resources Information Center

    Whitehead, Dean; Keast, John; Montgomery, Val; Hayman, Sue

    2004-01-01

    Objective: To investigate an existing Trust-based osteoporosis service's preventative activity, determine any issues and problems and use this data to reorganise the service, as part of a National Health Service Executive/Regional Office-commissioned and funded study. Setting: A UK Hospital Trust's Osteoporosis Service. Design & Method: A…

  16. Discourse-Based Language Intervention: An Efficacy Study.

    ERIC Educational Resources Information Center

    Skarakis-Doyle, Elizabeth; Murphy, Lisa

    1995-01-01

    This study of a 5-year-old girl with sensorineural hearing loss examined the effect of supplementing a pragmatically based procedure of focused stimulation with structured opportunities for verbal practice using vertical constructions. Results indicated that focused stimulation was an effective treatment procedure, especially when enhanced by the…

  17. The Effectiveness of Web-Based Instruction: A Case Study.

    ERIC Educational Resources Information Center

    White, Sylvia E.

    A case study compared web-based and classroom instruction. Subjects, 40 students enrolled in a Communication Technology and Change class, were divided by volunteers into an Internet section (16 students) and a regular classroom section (24 students.) Results indicated that in all cases the classroom section performed slightly better than the…

  18. Study of systems and techniques for data base management

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Data management areas were studied to identify pertinent problems and issues that will affect future NASA data users in terms of performance and cost. Specific topics discussed include the identifications of potential NASA data users other than those normally discussed, consideration affecting the clustering of minicomputers, low cost computer system for information retrieval and analysis, the testing of minicomputer based data base management systems, ongoing work related to the use of dedicated systems for data base management, and the problems of data interchange among a community of NASA data users.

  19. Dynamic 1H NMR Studies of Schiff Base Derivatives

    NASA Astrophysics Data System (ADS)

    Köylü, M. Z.; Ekinci, A.; Böyükata, M.; Temel, H.

    2016-01-01

    The spin-lattice relaxation time T 1 and the spin-spin relaxation time T 2 of two Schiff base derivatives, N,N'-ethylenebis(salicylidene)-1,2-diaminoethane (H2L1) and N,N'-ethylenebis (salicylidene)-1,3-diaminopropane (H2L2), in DMSO-d6 solvent were studied as a function of temperature in the range of 20-50°C using a Bruker Avance 400.132 MHz 1H NMR spectrometer. Based on the activation energy ( E a) and correlation time (τc), we believe that the Schiff base derivatives perform a molecular tumbling motion.

  20. Ontology-based federated data access to human studies information.

    PubMed

    Sim, Ida; Carini, Simona; Tu, Samson W; Detwiler, Landon T; Brinkley, James; Mollah, Shamim A; Burke, Karl; Lehmann, Harold P; Chakraborty, Swati; Wittkowski, Knut M; Pollock, Brad H; Johnson, Thomas M; Huser, Vojtech

    2012-01-01

    Human studies are one of the most valuable sources of knowledge in biomedical research, but data about their design and results are currently widely dispersed in siloed systems. Federation of these data is needed to facilitate large-scale data analysis to realize the goals of evidence-based medicine. The Human Studies Database project has developed an informatics infrastructure for federated query of human studies databases, using a generalizable approach to ontology-based data access. Our approach has three main components. First, the Ontology of Clinical Research (OCRe) provides the reference semantics. Second, a data model, automatically derived from OCRe into XSD, maintains semantic synchrony of the underlying representations while facilitating data acquisition using common XML technologies. Finally, the Query Integrator issues queries distributed over the data, OCRe, and other ontologies such as SNOMED in BioPortal. We report on a demonstration of this infrastructure on data acquired from institutional systems and from ClinicalTrials.gov. PMID:23304360

  1. Recent developments in microfluidics-based chemotaxis studies.

    PubMed

    Wu, Jiandong; Wu, Xun; Lin, Francis

    2013-07-01

    Microfluidic devices can better control cellular microenvironments compared to conventional cell migration assays. Over the past few years, microfluidics-based chemotaxis studies showed a rapid growth. New strategies were developed to explore cell migration in manipulated chemical gradients. In addition to expanding the use of microfluidic devices for a broader range of cell types, microfluidic devices were used to study cell migration and chemotaxis in complex environments. Furthermore, high-throughput microfluidic chemotaxis devices and integrated microfluidic chemotaxis systems were developed for medical and commercial applications. In this article, we review recent developments in microfluidics-based chemotaxis studies and discuss the new trends in this field observed over the past few years.

  2. Hypermedia-Based Problem Based Learning in the Upper Elementary Grades: A Developmental Study.

    ERIC Educational Resources Information Center

    Brinkerhoff, Jonathan D.; Glazewski, Krista

    This paper describes the application of problem-based learning (PBL) design principles and the inclusion of teacher and study scaffolds to the design and implementation of a hypermedia-based learning unit for the upper elementary/middle school grades. The study examined the following research questions: (1) Does hypermedia-based PBL represent an…

  3. Vegetation studies on Vandenberg Air Force Base, California

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.; Hickson, Diana E.; Hinkle, C. Ross

    1988-01-01

    Vandenburg Air Force Base, located in coastal central California with an area of 98,400 ac, contains resources of considerable biological significance. Available information on the vegetation and flora of Vandenburg is summarized and new data collected in this project are presented. A bibliography of 621 references dealing with vegetation and related topics related to Vanderburg was compiled from computer and manual literature searches and a review of past studies of the base. A preliminary floristic list of 642 taxa representing 311 genera and 80 families was compiled from past studies and plants identified in the vegetation sampling conducted in this project. Fifty-two special interest plant species are known to occur or were suggested to occur. Vegetation was sampled using permanent plots and transects in all major plant communities including chaparral, Bishop pine forest, tanbark oak forest, annual grassland, oak woodland, coastal sage scrub, purple sage scrub, coastal dune scrub, coastal dunes, box elder riparian woodland, will riparian woodland, freshwater marsh, salt marsh, and seasonal wetlands. Comparison of the new vegetation data to the compostie San Diego State University data does not indicate major changes in most communities since the original study. Recommendations are made for additional studies needed to maintain and extend the environmental data base and for management actions to improve resource protection.

  4. Partial gravity habitat study: With application to lunar base design

    NASA Technical Reports Server (NTRS)

    Capps, Stephen; Lorandos, Jason; Akhidime, Eval; Bunch, Michael; Lund, Denise; Moore, Nathan; Murakawa, Kio; Bell, Larry; Trotti, Guillermo; Neubek, Deb

    1989-01-01

    Comprehensive design requirements associated with designing habitats for humans in a partial gravity environment were investigated and then applied to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable gravity research facilities, or a rotating spacecraft. Design requirements for partial gravity environments include: (1) locomotion changes in less than normal Earth gravity; (2) facility design issues, such as interior configuration, module diameter and geometry; and (3) volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a Lunar Base, it was necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress. Radiation protection issues were addressed to provide a safe and healthy environment for the crew, and finally, the overall site was studied to locate all associated facilities in context with the habitat. Mission planning was not the purpose of this study; therefore, a Lockheed scenario was used as an outline for the Lunar Base application, which was then modified to meet the project needs.

  5. Studies on the Anthelmintic Property of Aminobenzylated Mannich Bases

    PubMed Central

    Chaluvaraju, KC; Bhat, KI

    2011-01-01

    Studies were conducted on the anthelmintic property of about 15(e-h, 1e-1h, 2d-2f and 3e-3h) synthesized aminobenzylated Mannich bases bearing N-methyl piperazine using Indian earthworms Pheritima Posthuma against piperazine citrate as standard reference. Three concentrations of each compound (0.1, 0.2, 0.3% w/v) were studied, which involved the determination of paralysis and death time of the worms. The compound 1g exhibited the most significant anthelmintic activity among all the compounds screened against the worms as compared to standard drug. PMID:21897666

  6. Evidence-based practice: reflections from five European case studies.

    PubMed

    Baeza, Juan I; Fraser, Alec; Boaz, Annette

    2014-01-01

    Background Evidence-based practice (EBP) is now the accepted orthodoxy in clinical practice and developed from evidence-based medicine. EBP is based on a specific type of evidence that is derived from studies based on randomised controlled trials (RCT). This type of evidence is suited to acute medical care and is more problematic for other clinicians such as nurses and therapists, particularly when they are situated within community or primary care settings. Setting Five stroke care services in England (2), Sweden (2) and Poland (1). Aims To reflect on the evidence gained from these case studies to shed light on various aspects of EBP. This paper focuses on three key issues: (1) the importance of context for evidence, (2) the nature of knowledge, and (3) professional hierarchies. Methods Five qualitative case studies into stroke care were carried out in England, Sweden and Poland. One hundred and twenty semi-structured interviews were carried out with a range of healthcare staff who provided specialised and non-specialised stroke care in acute, community and primary care between October 2010 and September 2011. Medical doctors, nurses and different therapists were included in the samples in all five case studies. For this paper, we reflect on some aspects of this work to illuminate the different interprofessional perspectives relating to EBP in stroke care. Results The lack of RCT-based evidence in the community and primary care sectors can lead to the clinicians working in these sectors being perceived as having a lower status. Clinicians use both tacit and encoded knowledge to guide their practice and there existed both intraand interprofessional tensions in these two types of knowledge. The professional hierarchy of stroke teams varies with national context and the role of the non-specialists is less valued in stroke care. PMID:25949726

  7. Complexity analysis of human physiological signals based on case studies

    NASA Astrophysics Data System (ADS)

    Angelova, Maia; Holloway, Philip; Ellis, Jason

    2015-04-01

    This work focuses on methods for investigation of physiological time series based on complexity analysis. It is a part of a wider programme to determine non-invasive markers for healthy ageing. We consider two case studies investigated with actigraphy: (a) sleep and alternations with insomnia, and (b) ageing effects on mobility patterns. We illustrate, using these case studies, the application of fractal analysis to the investigation of regulation patterns and control, and change of physiological function. In the first case study, fractal analysis techniques were implemented to study the correlations present in sleep actigraphy for individuals suffering from acute insomnia in comparison with healthy controls. The aim was to investigate if complexity analysis can detect the onset of adverse health-related events. The subjects with acute insomnia displayed significantly higher levels of complexity, possibly a result of too much activity in the underlying regulatory systems. The second case study considered mobility patterns during night time and their variations with age. It showed that complexity metrics can identify change in physiological function with ageing. Both studies demonstrated that complexity analysis can be used to investigate markers of health, disease and healthy ageing.

  8. Study of a risk-based piping inspection guideline system.

    PubMed

    Tien, Shiaw-Wen; Hwang, Wen-Tsung; Tsai, Chih-Hung

    2007-02-01

    A risk-based inspection system and a piping inspection guideline model were developed in this study. The research procedure consists of two parts--the building of a risk-based inspection model for piping and the construction of a risk-based piping inspection guideline model. Field visits at the plant were conducted to develop the risk-based inspection and strategic analysis system. A knowledge-based model had been built in accordance with international standards and local government regulations, and the rational unified process was applied for reducing the discrepancy in the development of the models. The models had been designed to analyze damage factors, damage models, and potential damage positions of piping in the petrochemical plants. The purpose of this study was to provide inspection-related personnel with the optimal planning tools for piping inspections, hence, to enable effective predictions of potential piping risks and to enhance the better degree of safety in plant operations that the petrochemical industries can be expected to achieve. A risk analysis was conducted on the piping system of a petrochemical plant. The outcome indicated that most of the risks resulted from a small number of pipelines.

  9. Case Studies in Agnotology-Based Learning (Invited)

    NASA Astrophysics Data System (ADS)

    Cook, J.; Bedford, D. P.; Mandia, S. A.

    2013-12-01

    Agnotology is the study of how and why ignorance or misconceptions exist. While misconceptions are a challenge for educators, they also present an opportunity to improve climate literacy through agnotology-based learning. This involves refutational lessons that challenge misconceptions while teaching scientific concepts. I will summarize two decades of research that find refutational texts are among the most effective forms of reducing misconceptions. I will present case studies in improving climate literacy through agnotology-based learning, both in the college classroom and in public outreach promoted through mainstream and social media. I will also explore how content from the SkepticalScience.com website is being used by educators as a teaching resource. These real-world examples demonstrate effective ways to reduce misperceptions and improve climate literacy.

  10. Market-Based Indian Grid Integration Study Options: Preprint

    SciTech Connect

    Stoltenberg, B.; Clark, K.; Negi, S. K.

    2012-03-01

    The Indian state of Gujarat is forecasting solar and wind generation expansion from 16% to 32% of installed generation capacity by 2015. Some states in India are already experiencing heavy wind power curtailment. Understanding how to integrate variable generation (VG) into the grid is of great interest to local transmission companies and India's Ministry of New and Renewable Energy. This paper describes the nature of a market-based integration study and how this approach, while new to Indian grid operation and planning, is necessary to understand how to operate and expand the grid to best accommodate the expansion of VG. Second, it discusses options in defining a study's scope, such as data granularity, generation modeling, and geographic scope. The paper also explores how Gujarat's method of grid operation and current system reliability will affect how an integration study can be performed.

  11. Faith based aviation: An ethnographic study of missionary flights international

    NASA Astrophysics Data System (ADS)

    Cooper, Joseph H.

    The development of faith-based missionary aviation is a post-World War II phenomenon. The war effort demonstrated the value, utility, and global reach of aviation to remote, underdeveloped areas of the world. With the beginnings of a worldwide infrastructure for aviation, Christian aviators realized aviation could increase the range and effectiveness of their efforts to reach the world for Christ (Mellis, 2006). Although individual organizations provide statistical information and data about flight operations there is a lack of external evidence and relevant research literature confirming the scope and value of these faith based aviation organizations and operations. A qualitative, ethnographic study was conducted to document the activities of one faith-based aviation organization to gain an understanding of this little known aspect of civilian aviation. The study was conducted with Missionary Flights International (MFI) of Fort Pierce, FL which has been involved in faith-based, missionary aviation since its inception in 1964. As an aviation organization "MFI strives to offer affiliated missions the kind of efficient service and professionalism expected of an airline operation" (Missionary Flights International, 2013, p.1). MFI is a lifeline for missionaries to Haiti and the Dominican Republic, fulfilling their motto of "Standing in the Gap". MFI provides twice a week service to the island of Hispaniola and the Republic of Haiti. In this in-depth study insight and understanding was gained into the purpose of MFI, their daily routines and operations, and the challenges they face in maintaining their flight services to Haiti. This study provided documentation of the value and utility of such aviation efforts and of the individuals involved in this endeavor.

  12. The prospects for urban densification: a place-based study

    NASA Astrophysics Data System (ADS)

    Schmidt-Thomé, Kaisa; Haybatollahi, Mohammad; Kyttä, Marketta; Korpi, Jari

    2013-06-01

    Study of the environmental outcomes of urban densification is a highly context-dependent task. Our study shows that collecting and processing place-based survey data by means of the softGIS method is clearly helpful here. With the map-based internet questionnaire each response remains connected to both the physical environment and the everyday life of the respondent. In our study of the Kuninkaankolmio area (located in the Helsinki metropolitan region) the survey data were combined with urban density variables calculated from register-based data on the existing built environment. The regression analysis indicated that the participants in the survey preferred the same density factors for their future residence as they enjoyed in their current neighbourhood. In the second analysis we related the densities of planned infill developments with the interest respondents had shown in these projects. The results show that new and even quite dense infill developments have been found to be rather attractive, with them often being viewed as interesting supplements to the current urban texture. These findings contribute to the ongoing scientific discussion on the feasibility of densification measures and encourage the Kuninkaankolmio planners to proceed, albeit carefully, with the planned infill developments.

  13. Feasibility Study of EO SARs as Opportunity Illuminators in Passive Radars: PAZ-Based Case Study.

    PubMed

    Bárcena-Humanes, Jose-Luis; Gómez-Hoyo, Pedro-José; Jarabo-Amores, Maria-Pilar; Mata-Moya, David; Del-Rey-Maestre, Nerea

    2015-01-01

    Passive radars exploit the signal transmitted by other systems, known as opportunity illuminators (OIs), instead of using their own transmitter. Due to its almost total invulnerability to natural disasters or physical attacks, satellite OIs are of special interest. In this line, a feasibility study of Earth Observation Synthetic Aperture Radar (EO SAR) systems as OIs is carried out taking into consideration signal waveform, availability, bistatic geometry, instrumented coverage area and incident power density. A case study based on the use of PAZ, the first Spanish EO SAR, is presented. PAZ transmitted waveform, operation modes, orbit characteristics and antenna and transmitter parameters are analyzed to estimate potential coverages and resolutions. The study concludes that, due to its working in on-demand operating mode, passive radars based on PAZ-type illuminators can be proposed as complementing tools during the sensor commissioning phase, for system maintenance and for improving its performance by providing additional information about the area of interest and/or increasing the data updating speed, exploiting other sensors during the time PAZ is not available. PMID:26593921

  14. Feasibility Study of EO SARs as Opportunity Illuminators in Passive Radars: PAZ-Based Case Study

    PubMed Central

    Bárcena-Humanes, Jose-Luis; Gómez-Hoyo, Pedro-José; Jarabo-Amores, Maria-Pilar; Mata-Moya, David; De-Rey-Maestre, Nerea

    2015-01-01

    Passive radars exploit the signal transmitted by other systems, known as opportunity illuminators (OIs), instead of using their own transmitter. Due to its almost total invulnerability to natural disasters or physical attacks, satellite OIs are of special interest. In this line, a feasibility study of Earth Observation Synthetic Aperture Radar (EO SAR) systems as OIs is carried out taking into consideration signal waveform, availability, bistatic geometry, instrumented coverage area and incident power density. A case study based on the use of PAZ, the first Spanish EO SAR, is presented. PAZ transmitted waveform, operation modes, orbit characteristics and antenna and transmitter parameters are analyzed to estimate potential coverages and resolutions. The study concludes that, due to its working in on-demand operating mode, passive radars based on PAZ-type illuminators can be proposed as complementing tools during the sensor commissioning phase, for system maintenance and for improving its performance by providing additional information about the area of interest and/or increasing the data updating speed, exploiting other sensors during the time PAZ is not available. PMID:26593921

  15. Feasibility Study of EO SARs as Opportunity Illuminators in Passive Radars: PAZ-Based Case Study.

    PubMed

    Bárcena-Humanes, Jose-Luis; Gómez-Hoyo, Pedro-José; Jarabo-Amores, Maria-Pilar; Mata-Moya, David; Del-Rey-Maestre, Nerea

    2015-11-17

    Passive radars exploit the signal transmitted by other systems, known as opportunity illuminators (OIs), instead of using their own transmitter. Due to its almost total invulnerability to natural disasters or physical attacks, satellite OIs are of special interest. In this line, a feasibility study of Earth Observation Synthetic Aperture Radar (EO SAR) systems as OIs is carried out taking into consideration signal waveform, availability, bistatic geometry, instrumented coverage area and incident power density. A case study based on the use of PAZ, the first Spanish EO SAR, is presented. PAZ transmitted waveform, operation modes, orbit characteristics and antenna and transmitter parameters are analyzed to estimate potential coverages and resolutions. The study concludes that, due to its working in on-demand operating mode, passive radars based on PAZ-type illuminators can be proposed as complementing tools during the sensor commissioning phase, for system maintenance and for improving its performance by providing additional information about the area of interest and/or increasing the data updating speed, exploiting other sensors during the time PAZ is not available.

  16. Ab initio Study of Naptho-Homologated DNA Bases

    SciTech Connect

    Sumpter, Bobby G; Vazquez-Mayagoitia, Alvaro; Huertas, Oscar; Fuentes-Cabrera, Miguel A; Orozco, Modesto; Luque, Javier

    2008-01-01

    Naptho-homologated DNA bases have been recently used to build a new type of size expanded DNA known as yyDNA. We have used theoretical techniques to investigate the structure, tautomeric preferences, base-pairing ability, stacking interactions, and HOMO-LUMO gaps of the naptho-bases. The structure of these bases is found to be similar to that of the benzo-fused predecessors (y-bases) with respect to the planarity of the aromatic rings and amino groups. Tautomeric studies reveal that the canonical-like form of naptho-thymine (yyT) and naptho-adenine (yyA) are the most stable tautomers, leading to hydrogen-bonded dimers with the corresponding natural nucleobases that mimic the Watson-Crick pairing. However, the canonical-like species of naptho-guanine (yyG) and naptho-cytosine (yyC) are not the most stable tautomers, and the most favorable hydrogen-bonded dimers involve wobble-like pairings. The expanded size of the naphto-bases leads to stacking interactions notably larger than those found for the natural bases, and they should presumably play a dominant contribution in modulating the structure of yyDNA duplexes. Finally, the HOMO-LUMO gap of the naptho-bases is smaller than that of their benzo-base counterparts, indicating that size-expansion of DNA bases is an efficient way of reducing their HOMO-LUMO gap. These results are examined in light of the available experimental evidence reported for yyT and yyC.

  17. A population-based study of the stratum corneum moisture

    PubMed Central

    de Farias Pires, Thiago; Azambuja, Ana Paula; Horimoto, Andrea Roseli Vançan Russo; Nakamura, Mary Sanae; de Oliveira Alvim, Rafael; Krieger, José Eduardo; Pereira, Alexandre Costa

    2016-01-01

    Background The stratum corneum (SC) has important functions as a bound-water modulator and a primary barrier of the human skin from the external environment. However, no large epidemiological study has quantified the relative importance of different exposures with regard to these functional properties. In this study, we have studied a large sample of individuals from the Brazilian population in order to understand the different relationships between the properties of SC and a number of demographic and self-perceived variables. Methods One thousand three hundred and thirty-nine individuals from a rural Brazilian population, who were participants of a family-based study, were submitted to a cross-sectional examination of the SC moisture by capacitance using the Corneometer® CM820 and investigated regarding environmental exposures, cosmetic use, and other physiological and epidemiological measurements. Self-perception-scaled questions about skin conditions were also applied. Results We found significant associations between SC moisture and sex, age, high sun exposure, and sunscreen use frequency (P<0.025). In specific studied sites, self-reported race and obesity were also found to show significant effects. Dry skin self-perception was also found to be highly correlated with the objective measurement of the skin. Other environmental effects on SC moisture are also reported. PMID:27143945

  18. Set-based tests for genetic association in longitudinal studies.

    PubMed

    He, Zihuai; Zhang, Min; Lee, Seunggeun; Smith, Jennifer A; Guo, Xiuqing; Palmas, Walter; Kardia, Sharon L R; Diez Roux, Ana V; Mukherjee, Bhramar

    2015-09-01

    Genetic association studies with longitudinal markers of chronic diseases (e.g., blood pressure, body mass index) provide a valuable opportunity to explore how genetic variants affect traits over time by utilizing the full trajectory of longitudinal outcomes. Since these traits are likely influenced by the joint effect of multiple variants in a gene, a joint analysis of these variants considering linkage disequilibrium (LD) may help to explain additional phenotypic variation. In this article, we propose a longitudinal genetic random field model (LGRF), to test the association between a phenotype measured repeatedly during the course of an observational study and a set of genetic variants. Generalized score type tests are developed, which we show are robust to misspecification of within-subject correlation, a feature that is desirable for longitudinal analysis. In addition, a joint test incorporating gene-time interaction is further proposed. Computational advancement is made for scalable implementation of the proposed methods in large-scale genome-wide association studies (GWAS). The proposed methods are evaluated through extensive simulation studies and illustrated using data from the Multi-Ethnic Study of Atherosclerosis (MESA). Our simulation results indicate substantial gain in power using LGRF when compared with two commonly used existing alternatives: (i) single marker tests using longitudinal outcome and (ii) existing gene-based tests using the average value of repeated measurements as the outcome.

  19. Learning through Web-Based Multistoryline Case Studies: A Design-Based Research

    ERIC Educational Resources Information Center

    Zeng, Rui; Blasi, Laura

    2010-01-01

    This article describes a design-based research in an undergraduate measurement and evaluation course. The study employed web-based multistoryline case studies grounded on Spiro's cognitive flexibility theory to improve students' comprehension of concepts and knowledge. The findings of this research reveal that students demonstrated positive…

  20. Social Studies Teachers' Use of Classroom-Based and Web-Based Historical Primary Sources

    ERIC Educational Resources Information Center

    Hicks, David; Doolittle, Peter; Lee, John K.

    2004-01-01

    A limited body of research examines the extent to which social studies teachers are actually utilizing primary sources that are accessible in traditional classroom-based formats versus web-based formats. This paper initiates an exploration of this gap in the literature by reporting on the result of a survey of secondary social studies teachers,…

  1. Resonance Energy Transfer-Based Approaches to Study GPCRs.

    PubMed

    Ayoub, Mohammed Akli

    2016-01-01

    Since their discovery, G protein-coupled receptors (GPCRs) constitute one of the most studied proteins leading to important discoveries and perspectives in terms of their biology and implication in physiology and pathophysiology. This is mostly linked to the remarkable advances in the development and application of the biophysical resonance energy transfer (RET)-based approaches, including bioluminescence and fluorescence resonance energy transfer (BRET and FRET, respectively). Indeed, BRET and FRET have been extensively applied to study different aspects of GPCR functioning such as their activation and regulation either statically or dynamically, in real-time and intact cells. Consequently, our view on GPCRs has considerably changed opening new challenges for the study of GPCRs in their native tissues in the aim to get more knowledge on how these receptors control the biological responses. Moreover, the technological aspect of this field of research promises further developments for robust and reliable new RET-based assays that may be compatible with high-throughput screening as well as drug discovery programs.

  2. Laboratory-Based Studies of Eating among Children and Adolescents

    PubMed Central

    Tanofsky-Kraff, Marian; Haynos, Ann F.; Kotler, Lisa A.; Yanovski, Susan Z.; Yanovski, Jack A.

    2008-01-01

    The prevalence of pediatric overweight has increased dramatically over the past three decades, likely due to changes in food intake as well as physical activity. Therefore, information examining eating patterns among children and adolescents is needed to illuminate which aspects of eating behavior require modification to prevent and treat pediatric overweight. Because child self-report and parent-report of children's eating habits are often inconsistent and limited by recall and other biases, laboratory-based studies in which food intake is observed and monitored have increased in number. Such studies offer objective and controlled methods of measuring and describing eating behaviors. However, to our knowledge, no publication exists that consolidates, reviews, and provides critical commentary on the literature to date in pediatric samples. In this paper, we review the literature of studies utilizing laboratory methods to examine eating behavior in samples ranging from birth through adolescence. Our review includes all relevant articles retrieved from the PubMed, Medline and PsychInfo search engines. Specifically, we examine meal-feeding studies conducted during the various developmental stages (infancy, preschool, middle childhood, and adolescence), with a focus on methodology. Included in our review are feeding studies related to dietary regulation, exposure and preference, as well as paradigms examining disordered eating patterns and their relationship to body composition. We have structured this review so that both consistent and inconsistent findings are presented by age group, and innovative methods of assessment are discussed in more detail. Following each section, we summarize findings and draw potential conclusions from the available data. We then discuss clinical implications of the research data and suggest directions for the next generation of studies of feeding behavior in children. PMID:19030122

  3. X-33 Base Region Thermal Protection System Design Study

    NASA Technical Reports Server (NTRS)

    Lycans, Randal W.

    1998-01-01

    The X-33 is an advanced technology demonstrator for validating critical technologies and systems required for an operational Single-Stage-to-Orbit (SSTO) Reusuable Launch Vehicle (RLV). Currently under development by a unique contractor/government team led by Lockheed- Martin Skunk Works (LMSW), and managed by Marshall Space Flight Center (MSFC), the X-33 will be the prototype of the first new launch system developed by the United States since the advent of the space shuttle. This paper documents a design trade study of the X-33 base region thermal protection system (TPS). Two candidate designs were evaluated for thermal performance and weight. The first candidate was a fully reusable metallic TPS using Inconel honeycomb panels insulated with high temperature fibrous insulation, while the second was an ablator/insulator sprayed on the metallic skin of the vehicle. The TPS configurations and insulation thickness requirements were determined for the predicted main engine plume heating environments and base region entry aerothermal environments. In addition to thermal analysis of the design concepts, sensitivity studies were performed to investigate the effect of variations in key parameters of the base TPS analysis.

  4. A hospital-based study of abortion in Nepal.

    PubMed

    Thapa, P J; Thapa, S; Shrestha, N

    1992-01-01

    This report presents the major findings of a study of induced abortion in Nepal, based on 165 cases out of the 1,576 female patients identified as having abortion-related complications who were admitted to five major hospitals in urban Nepal during a one-year study period. Traditional birth attendants had been the service providers for two-fifths of the women. A longer delay in hospital referrals and lengthier hospital stays occurred for cases of induced abortion than for those of spontaneous abortion. Twelve of the 165 women in the study died in the hospital, most of them from tetanus. Deaths resulting from abortion-related complications represented more than half of all maternity-related deaths in the hospitals studied. The authors suggest that health risks could be reduced considerably by strengthening the hospital-referral system and by taking some preventive steps, such as educating the traditional birth attendants and other paramedical providers about the consequences of unsafe abortion practices; increasing the availability of contraceptive methods; and promoting the use of menstrual regulation, which has recently become available in Nepal on a limited scale, mostly in private clinics.

  5. A study of a tissue equivalent gelatine based tissue substitute

    SciTech Connect

    Spence, J.L.

    1992-11-01

    A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man which was used as a basis for this study. The evaluation was based on the electron stopping power, the mass attenuation coefficient, the electron density, and the specific gravity. The tissue substitute chosen also had to be capable of changing from a liquid into a solid form to maintain an even distribution of thermoluminesent dosimetry (TLD) powder and then back to a liquid for recovery of the TLD powder without adversely effecting the TLD powder. The gelatine mixture provided the closest match to the data from Reference Man tissue. The gelatine mixture was put through a series of test to determine it`s usefulness as a reliable tissue substitute. The TLD powder was cast in the gelatine mixture and recovered to determine if the TLD powder was adversely effected. The distribution of the TLD powder after being cast into the gelatin mixture was tested in insure an even was maintained.

  6. A study of a tissue equivalent gelatine based tissue substitute

    SciTech Connect

    Spence, J.L.

    1992-11-01

    A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man which was used as a basis for this study. The evaluation was based on the electron stopping power, the mass attenuation coefficient, the electron density, and the specific gravity. The tissue substitute chosen also had to be capable of changing from a liquid into a solid form to maintain an even distribution of thermoluminesent dosimetry (TLD) powder and then back to a liquid for recovery of the TLD powder without adversely effecting the TLD powder. The gelatine mixture provided the closest match to the data from Reference Man tissue. The gelatine mixture was put through a series of test to determine it's usefulness as a reliable tissue substitute. The TLD powder was cast in the gelatine mixture and recovered to determine if the TLD powder was adversely effected. The distribution of the TLD powder after being cast into the gelatin mixture was tested in insure an even was maintained.

  7. Fuzzy-based HAZOP study for process industry.

    PubMed

    Ahn, Junkeon; Chang, Daejun

    2016-11-01

    This study proposed a fuzzy-based HAZOP for analyzing process hazards. Fuzzy theory was used to express uncertain states. This theory was found to be a useful approach to overcome the inherent uncertainty in HAZOP analyses. Fuzzy logic sharply contrasted with classical logic and provided diverse risk values according to its membership degree. Appropriate process parameters and guidewords were selected to describe the frequency and consequence of an accident. Fuzzy modeling calculated risks based on the relationship between the variables of an accident. The modeling was based on the mean expected value, trapezoidal fuzzy number, IF-THEN rules, and the center of gravity method. A cryogenic LNG (liquefied natural gas) testing facility was the objective process for the fuzzy-based and conventional HAZOPs. The most significant index is the frequency to determine risks. The comparison results showed that the fuzzy-based HAZOP provides better sophisticated risks than the conventional HAZOP. The fuzzy risk matrix presents the significance of risks, negligible risks, and necessity of risk reduction. PMID:27318726

  8. Fuzzy-based HAZOP study for process industry.

    PubMed

    Ahn, Junkeon; Chang, Daejun

    2016-11-01

    This study proposed a fuzzy-based HAZOP for analyzing process hazards. Fuzzy theory was used to express uncertain states. This theory was found to be a useful approach to overcome the inherent uncertainty in HAZOP analyses. Fuzzy logic sharply contrasted with classical logic and provided diverse risk values according to its membership degree. Appropriate process parameters and guidewords were selected to describe the frequency and consequence of an accident. Fuzzy modeling calculated risks based on the relationship between the variables of an accident. The modeling was based on the mean expected value, trapezoidal fuzzy number, IF-THEN rules, and the center of gravity method. A cryogenic LNG (liquefied natural gas) testing facility was the objective process for the fuzzy-based and conventional HAZOPs. The most significant index is the frequency to determine risks. The comparison results showed that the fuzzy-based HAZOP provides better sophisticated risks than the conventional HAZOP. The fuzzy risk matrix presents the significance of risks, negligible risks, and necessity of risk reduction.

  9. Studying inflation with future space-based gravitational wave detectors

    SciTech Connect

    Jinno, Ryusuke; Moroi, Takeo; Takahashi, Tomo E-mail: moroi@phys.s.u-tokyo.ac.jp

    2014-12-01

    Motivated by recent progress in our understanding of the B-mode polarization of cosmic microwave background (CMB), which provides important information about the inflationary gravitational waves (IGWs), we study the possibility to acquire information about the early universe using future space-based gravitational wave (GW) detectors. We perform a detailed statistical analysis to estimate how well we can determine the reheating temperature after inflation as well as the amplitude, the tensor spectral index, and the running of the inflationary gravitational waves. We discuss how the accuracies depend on noise parameters of the detector and the minimum frequency available in the analysis. Implication of such a study on the test of inflation models is also discussed.

  10. Structural Studies of Pterin-Based Inhibitors of Dihydropteroate Synthase

    SciTech Connect

    Hevener, Kirk E.; Yun, Mi-Kyung; Qi, Jianjun; Kerr, Iain D.; Babaoglu, Kerim; Hurdle, Julian G.; Balakrishna, Kanya; White, Stephan W.; Lee, Richard E.

    2010-01-12

    Dihydropteroate synthase (DHPS) is a key enzyme in bacterial folate synthesis and the target of the sulfonamide class of antibacterials. Resistance and toxicities associated with sulfonamides have led to a decrease in their clinical use. Compounds that bind to the pterin binding site of DHPS, as opposed to the p-amino benzoic acid (pABA) binding site targeted by the sulfonamide agents, are anticipated to bypass sulfonamide resistance. To identify such inhibitors and map the pterin binding pocket, we have performed virtual screening, synthetic, and structural studies using Bacillus anthracis DHPS. Several compounds with inhibitory activity have been identified, and crystal structures have been determined that show how the compounds engage the pterin site. The structural studies identify the key binding elements and have been used to generate a structure-activity based pharmacophore map that will facilitate the development of the next generation of DHPS inhibitors which specifically target the pterin site.

  11. Frame semantics-based study of verbs across medical genres.

    PubMed

    Wandji Tchami, Ornella; L'Homme, Marie-Claude; Grabar, Natalia

    2014-01-01

    The field of medicine gathers actors with different levels of expertise. These actors must interact, although their mutual understanding is not always completely successful. We propose to study corpora (with high and low levels of expertise) in order to observe their specificities. More specifically, we perform a contrastive analysis of verbs, and of the syntactic and semantic features of their participants, based on the Frame Semantics framework and the methodology implemented in FrameNet. In order to achieve this, we use an existing medical terminology to automatically annotate the semantics classes of participants of verbs, which we assume are indicative of semantics roles. Our results indicate that verbs show similar or very close semantics in some contexts, while in other contexts they behave differently. These results are important for studying the understanding of medical information by patients and for improving the communication between patients and medical doctors.

  12. Feasibility Study for an Asymmetric B Factory Based on PEP

    SciTech Connect

    Chattapadhyay, A.; Hitlin, D.; Porter, F.; Chin, Y.H.; Dell'Orco, D.; Forest, E.; Furman, M.; Garren, A.A.; Hoyer, E.; Kennedy, K.; Lambertson, G.; Lo, C.C.; Nishimura, H.; Oddone, P.; Ronan, M.; Sessler, A.; Taylor, B.; Taylor, C.; Zisman, M.; Barletta, W.; Allen, M.; Bloom, E.; Burke, D.; Cornacchia, M.; Davies-White, D.; Destaebler, H.; Donald, M.H.; Dorfan, J.; Feldman, G.; Rees, J.; Schsarz, H.; Sullivan, M.; Autin, B.; Tennyson, J.; Barbson, B.; Oide, K.

    1989-10-26

    This report addresses the feasibility of designing and constructing an asymmetric B-factory based on the PEP storage ring at SLAC that can ultimately reach a luminosity of 1 X 10{sup 34} cm{sup -2}s{sup -1}. Such a facility, operating at the {gamma}(4S) resonance, could be used to study mixing, rate decays, and CP violation in the B{bar B} system, and could also study tau and charm physics. The essential accelerator physics, engineering, and technology issues that must be addressed to successfully build this exciting and challenging facility are identified, and possible solutions, or R and D that will reasonable lead to such solutions, are described.

  13. Increasing incidence of Barrett's oesophagus: a population-based study.

    PubMed

    Coleman, Helen G; Bhat, Shivaram; Murray, Liam J; McManus, Damian; Gavin, Anna T; Johnston, Brian T

    2011-09-01

    Oesophageal adenocarcinoma, a highly fatal cancer, has risen in incidence in Western societies, but it is unclear whether this is due to increasing incidence of its pre-cursor condition, Barrett's oesophagus (BO) or whether the proportion of BO patients undergoing malignant progression has increased in the face of unchanged BO incidence. Data from population-based studies of BO incidence is limited, with equivocal results to date difficult to distinguish from changes in endoscopic practices. The aim of this study was to assess population trends in Barrett's oesophagus (BO) diagnoses in relation to endoscopy and biopsy rates over a 13 year period. The Northern Ireland Barrett's oesophagus Register (NIBR) is a population-based register of all 9,329 adults diagnosed with columnar epithelium of the oesophagus in Northern Ireland between 1993 and 2005, of whom 58.3% were male. European age-standardised annual BO incidence rates were calculated per 100,000 of the population, per 100 endoscopies and per 100 endoscopies including an oesophageal biopsy. Average annual BO incidence rates rose by 159% during the study period, increasing from 23.9/100,000 during 1993-1997 to 62.0/100,000 during 2002-2005. This elevation far exceeded corresponding increases in rates of endoscopies and oesophageal biopsies being conducted. BO incidence increased most markedly in individuals aged < 60 years, and most notably amongst males aged < 40 years. This study points towards a true increase in the incidence of BO which would appear to be most marked in young males. These findings have significant implications for future rates of oesophageal adenocarcinoma and surveillance programmes.

  14. Macrolide-induced digoxin toxicity: a population-based study.

    PubMed

    Gomes, T; Mamdani, M M; Juurlink, D N

    2009-10-01

    In this 15-year, population-based, nested case-control study, we investigated the association between hospitalization for digoxin toxicity and recent exposure to individual macrolide antibiotics. Clarithromycin was associated with the highest risk of digoxin toxicity (adjusted odds ratio (OR) 14.8; 95% confidence interval (CI) 7.9-27.9), whereas erythromycin and azithromycin were associated with much lower risk (adjusted OR 3.7; 95% CI 1.7-7.9; and adjusted OR 3.7; 95% CI 1.1-12.5, respectively). We found no increased risk with a neutral comparator, cefuroxime (adjusted OR 0.8; 95% CI 0.2-3.4).

  15. Preliminary study of digital image correlation based optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Sun, Cuiru; Vuong, Barry; Wen, Xiao-Yan; Yang, Victor

    2013-06-01

    Optical coherence elastography (OCE) provides deformation or material properties mapping of soft tissue, which is important for morphological and pathological studies of the tissue. An OCE technique is developed based on digital image correlation. System calibration and measurement error evaluation are performed. The displacement measurement of 0.6 μm to over 100 μm was obtained through a phantom experiment. The capability of this OCE technique for differentiation of stiffness was evaluated by imaging a two-components phantom. OCE imaging of an aneurysm sample shows promising results for characterization of composites of aneurismal wall in the future.

  16. Feasibility study of a microprocessor based oculometer system

    NASA Technical Reports Server (NTRS)

    Varanasi, M. R.

    1981-01-01

    The elimination of redundancy in data to maximize processing speed and minimize storage requirements were objectives in a feasibility study of a microprocessor based oculometer system that would be portable in size and flexible in use. The appropriate architectural design of the signal processor, improved optics, and the reduction of size, weight, and power to the system were investigated. A flow chart is presented showing the strategy of the design. The simulation for developing microroutines for the high speed algorithmic processor subsystem is discussed as well as the Karhunen-Loeve transform technique for data compression.

  17. DENSITY-FUNCTIONAL STUDY OF Zr-BASED ACTINIDE ALLOYS

    SciTech Connect

    Landa, A; Soderlind, P; Turchi, P; Vitos, L; Ruban, A

    2008-06-26

    Density-functional formalism is applied to study the phase equilibria in the U-Zr system. The obtained ground-state properties of the {gamma} (bcc) and {delta} (C32) phases are in good agreement with experimental data. The decomposition curve for the {gamma}-based U-Zr solutions is calculated. We argue that stabilization of the {delta}-UZr{sub 2} phase relative to the {alpha}-Zr (hcp) structure is due to an increase of the Zr d-band occupancy that occurs when U is alloyed with Zr.

  18. Ab-initio study of napthelene based conducting polymer

    SciTech Connect

    Ruhela, Ankur; Kanchan, Reena; Srivastava, Anurag; Sinha, O. P.

    2014-04-24

    In this paper, we have identified structural and electronic properties of conducting polymers by using DFT based ATK-VNL ab-initio tool. Naphthalene derivative structures were stabilized by varying the bond length between two atoms of the molecule C-N and C-C. We have also studied the molecular energy spectrum of naphthalene derivatives and found the HOMOLUMO for the same. A comparison of structural and electronic properties of naphthalene derivatives by attaching the functional group of amine, have been performed and found that they show good semi conducting properties.

  19. Geothermal studies at Kirtland Air Force Base, Albuquerque, New Mexico

    SciTech Connect

    Riddle, L.; Grant, B.

    1981-05-01

    Due to an effort by government installations to discontinue use of natural gas, alternative energy sources are being investigated at Kirtland Air Force Base, Albuquerque, New Mexico. New Mexico has geologic characteristics favorable for geothermal energy utilization. Local heat flow and geochemical studies indicate a normal subsurface temperature regime. The alluvial deposits, however, extend to great depths where hot fluids, heated by the normal geothermal gradient, could be encountered. Two potential models for tapping geothermal energy are presented: the basin model and the fault model.

  20. Natural oils and waxes: studies on stick bases.

    PubMed

    Budai, Lívia; Antal, István; Klebovich, Imre; Budai, Marianna

    2012-01-01

    The objective of the present article was to examine the role of origin and quantity of selected natural oils and waxes in the determination of the thermal properties and hardness of stick bases. The natural oils and waxes selected for the study were sunflower, castor, jojoba, and coconut oils. The selected waxes were yellow beeswax, candelilla wax, and carnauba wax. The hardness of the formulations is a critical parameter from the aspect of their application. Hardness was characterized by the measurement of compression strength along with the softening point, the drop point, and differential scanning calorimetry (DSC). It can be concluded that coconut oil, jojoba oil, and carnauba wax have the greatest influence on the thermal parameters of stick bases.

  1. A simulation based case study for control of DSTATCOM.

    PubMed

    Kumar, Pradeep; Kumar, Niranjan; Akella, A K

    2014-05-01

    This paper presents a distribution static compensator (DSTATCOM) for power quality improvements in terms of harmonics and power factor correction in a three-phase four-wire distribution system. The DSTATCOM is implemented with PWM current controlled six-leg voltage source converter (VSC) and the switching patterns are generated through a novel synchronous reference frame controller (SRFC). The insulated gate bipolar transistor (IGBT) based VSC is supported by a capacitor and is controlled for the required compensation of the load current. The DSTATCOM is connected to the power system feeding nonlinear loads. Nonlinear loads include either current-source type or voltage-source type. Harmonic spectrum of the source current is compared in between without DSTATCOM and with DSTATCOM by considering both types of nonlinear loads. The SRFC based DSTATCOM system is validated through extensive simulation for diode-rectifier and unbalanced R-L loads with a case study. PMID:24656282

  2. Model-based estimation for dynamic cardiac studies using ECT

    SciTech Connect

    Chiao, P.C.; Rogers, W.L.; Clinthorne, N.H.; Fessler, J.A.; Hero, A.O. . Div. of Nuclear Medicine)

    1994-06-01

    In this paper, the authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (Emission Computed Tomography). The authors construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. The authors also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, model assumptions and potential uses of the joint estimation strategy are discussed.

  3. Saccharomyces cerevisiae-based system for studying clustered DNA damages

    SciTech Connect

    Moscariello, M.M.; Sutherland, B.

    2010-08-01

    DNA-damaging agents can induce clustered lesions or multiply damaged sites (MDSs) on the same or opposing DNA strands. In the latter, attempts to repair MDS can generate closely opposed single-strand break intermediates that may convert non-lethal or mutagenic base damage into double-strand breaks (DSBs). We constructed a diploid S. cerevisiae yeast strain with a chromosomal context targeted by integrative DNA fragments carrying different damages to determine whether closely opposed base damages are converted to DSBs following the outcomes of the homologous recombination repair pathway. As a model of MDS, we studied clustered uracil DNA damages with a known location and a defined distance separating the lesions. The system we describe might well be extended to assessing the repair of MDSs with different compositions, and to most of the complex DNA lesions induced by physical and chemical agents.

  4. Studies of oceanic tectonics based on GEOS-3 satellite altimetry

    NASA Technical Reports Server (NTRS)

    Poehls, K. A.; Kaula, W. M.; Schubert, G.; Sandwell, D.

    1979-01-01

    Using statistical analysis, geoidal admittance (the relationship between the ocean geoid and seafloor topography) obtained from GEOS-3 altimetry was compared to various model admittances. Analysis of several altimetry tracks in the Pacific Ocean demonstrated a low coherence between altimetry and seafloor topography except where the track crosses active or recent tectonic features. However, global statistical studies using the much larger data base of all available gravimetry showed a positive correlation of oceanic gravity with topography. The oceanic lithosphere was modeled by simultaneously inverting surface wave dispersion, topography, and gravity data. Efforts to incorporate geoid data into the inversion showed that the base of the subchannel can be better resolved with geoid rather than gravity data. Thermomechanical models of seafloor spreading taking into account differing plate velocities, heat source distributions, and rock rheologies were discussed.

  5. Metallomics insights for in vivo studies of metal based nanomaterials.

    PubMed

    Wang, Bing; Feng, Weiyue; Zhao, Yuliang; Chai, Zhifang

    2013-06-01

    With the rapid development of engineered nanomaterials (NMs) and wide biomedical applications for new types of multifunctional NMs, an understanding of the behavior patterns of NMs in vivo and clarification of their potential health impact as a result of their novel physicochemical properties is essential for ensuring safety in biomedical applications of nanotechnology. NMs have heterogeneous characteristics in that they combine the bulk properties of solids with the mobility of molecules, and present phase transformation, dissolution, oxidation/reduction as well as nano-bio interface reactions in biological milieu, which affect their in vivo behaviors and biological effects. The accurate study of identification, quantification, transformation state of NMs and their biological effects in vivo remains a challenge. This review aims to provide a "metallomics" (an integrated metal-assisted function bioscience) insight into the in vivo behavior and biological effects of NMs, particularly for metal-based nanomaterials (MNMs) and is based mainly on our own research and other previous works.

  6. Cutoff Designs for Community-Based Intervention Studies

    PubMed Central

    Pennell, Michael L.; Hade, Erinn M.; Murray, David M.; Rhoda, Dale A.

    2011-01-01

    Summary Public health interventions are often designed to target communities defined either geographically (e.g., cities, counties) or socially (e.g., schools or workplaces). The group randomized trial (GRT) is regarded as the gold standard for evaluating these interventions. However, community leaders may object to randomization as some groups may be denied a potentially beneficial intervention. Under a regression discontinuity design (RDD), individuals may be assigned to treatment based on the levels of a pretest measure, thereby allowing those most in need of the treatment to receive it. In this article, we consider analysis, power, and sample size issues in applying the RDD and related cutoff designs in community-based intervention studies. We examine the power of these designs as a function of intraclass correlation, number of groups, and number of members per group and compare results to the traditional GRT. PMID:21500240

  7. Laminar Premixed and Diffusion Flames (Ground-Based Study)

    NASA Technical Reports Server (NTRS)

    Dai, Z.; El-Leathy, A. M.; Lin, K.-C.; Sunderland, P. B.; Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2000-01-01

    Ground-based studies of soot processes in laminar flames proceeded in two phases, considering laminar premixed flames and laminar diffusion flames, in turn. The test arrangement for laminar premixed flames involved round flat flame burners directed vertically upward at atmospheric pressure. The test arrangement for laminar jet diffusion flames involved a round fuel port directed vertically upward with various hydrocarbon fuels burning at atmospheric pressure in air. In both cases, coflow was used to prevent flame oscillations and measurements were limited to the flame axes. The measurements were sufficient to resolve soot nucleation, growth and oxidation rates, as well as the properties of the environment needed to evaluate mechanisms of these processes. The experimental methods used were also designed to maintain capabilities for experimental methods used in corresponding space-based experiments. This section of the report will be limited to consideration of flame structure for both premixed and diffusion flames.

  8. Data base dictionary for the Oak Ridge Reservation Hydrology and Geology Study Groundwater Data Base

    SciTech Connect

    Thompson, B.K.

    1993-04-01

    The Oak Ridge Reservation Hydrology and Geology Study (ORRHAGS) Groundwater Data Base has been compiled to consolidate groundwater data from the three US Department of Energy facilities located on the Oak Ridge Reservation: the Oak Ridge K-25 Site, the Oak Ridge National Laboratory, and the Oak Ridge Y-12 Plant. Each of these facilities maintains its own groundwater and well construction data bases. Data were extracted from the existing data bases, converted to a consistent format, and integrated into the ORRHAGS Groundwater Data Base structures. This data base dictionary describes the data contained in the ORRHAGS Groundwater Data Base and contains information on data base structure, conventions, contents, and use.

  9. Study on Cloud Security Based on Trust Spanning Tree Protocol

    NASA Astrophysics Data System (ADS)

    Lai, Yingxu; Liu, Zenghui; Pan, Qiuyue; Liu, Jing

    2015-09-01

    Attacks executed on Spanning Tree Protocol (STP) expose the weakness of link layer protocols and put the higher layers in jeopardy. Although the problems have been studied for many years and various solutions have been proposed, many security issues remain. To enhance the security and credibility of layer-2 network, we propose a trust-based spanning tree protocol aiming at achieving a higher credibility of LAN switch with a simple and lightweight authentication mechanism. If correctly implemented in each trusted switch, the authentication of trust-based STP can guarantee the credibility of topology information that is announced to other switch in the LAN. To verify the enforcement of the trusted protocol, we present a new trust evaluation method of the STP using a specification-based state model. We implement a prototype of trust-based STP to investigate its practicality. Experiment shows that the trusted protocol can achieve security goals and effectively avoid STP attacks with a lower computation overhead and good convergence performance.

  10. Endometrial cancer and antidepressants: A nationwide population-based study.

    PubMed

    Lin, Chiao-Fan; Chan, Hsiang-Lin; Hsieh, Yi-Hsuan; Liang, Hsin-Yi; Chiu, Wei-Che; Huang, Kuo-You; Lee, Yena; McIntyre, Roger S; Chen, Vincent Chin-Hung

    2016-07-01

    To our knowledge, the association between antidepressant exposure and endometrial cancer has not been previously explored. Herein, we aim to investigate the association between antidepressant prescription, including novel antidepressants, and the risk for endometrial cancer in a population-based study.Data for the analysis were derived from National Health Insurance Research Database. We identified 8392 cases with a diagnosis of endometrial cancer and 82,432 matched controls. A conditional logistic regression model was used, with adjusting for potentially confounding variables (e.g., comorbid psychiatric diseases, comorbid physical diseases, and other medications). Risk for endometrial cancer in the population-based study sample was categorized by, and assessed as a function of, antidepressant prescription and cumulative dosage.We report no association between endometrial cancer incidence and antidepressant prescription, including those prescribed either selective serotonin reuptake inhibitors (adjusted odds ratio [OR] = 0.98; 95% confidence interval [CI], 0.84-1.15) or serotonin norepinephrine reuptake inhibitors (adjusted OR = 1.14; 95% CI, 0.76-1.71). We also did not identify an association between higher cumulative doses of antidepressant prescription and endometrial cancer.There was no association between antidepressant prescription and endometrial cancer. PMID:27442640

  11. Amidated pectin based hydrogels: synthesis, characterization and cytocompatibility study.

    PubMed

    Mishra, R K; Singhal, J P; Datt, M; Banthia, A K

    2007-01-01

    The design and development of pectin-based hydrogels were attempted through the chemical modification of pectin with diethanolamine (DA). Diethanolamine modified pectin (DAMP) was synthesized by the chemical modification of pectin with varying concentrations of DA (1:1,1:2,1:3 and 1:4) at 5 oC in methanol. The modified product was used for the preparation of the hydrogel with glutaraldehyde (GA) reagent. The prepared hydrogels were characterized by Fourier transform infrared (FTIR) spectroscopy; organic elemental analysis, and X-ray diffraction (XRD), and swelling, hemocompatibility and cytocompatibility studies of the prepared hydrogels were also done. FTIR spectroscopy indicated the presence of primary and secondary amide absorption bands. The XRD pattern of the DAMP hydrogel clearly indicated that there was a considerable increase in crystallinity as compared to parent pectin. The degree of amidation (DA) and molar and mass reaction yields (Ym and Yn) was calculated based on the results of organic elemental analysis. Drug release studies from the hydrogel membranes were also evaluated in a Franz's diffusion cell. The hydrogels demonstrated good water holding properties and were found to be compatible with B-16 melanoma cells and human blood.

  12. Kinetic study on urea uptake with chitosan based sorbent materials.

    PubMed

    Xue, Chen; Wilson, Lee D

    2016-01-01

    A one-pot kinetic uptake study of urea in aqueous solution with various chitosan sorbent materials such as pristine chitosan, cross-linked chitosan with glutaraldehyde from low (C-1) to higher (C-2) glutaraldehyde content, and a Cu(II) complex of a glutaraldehyde cross-linked chitosan material (C-3) is reported herein. The kinetic uptake profiles were analyzed by the pseudo-first order (PFO) and pseudo-second-order (PSO) models, respectively. The uptake rate constant of urea and the sorption capacity (qe) of high molecular weight (HMW) chitosan, C-1, C-2, and C-3 were best described by the PFO model. The uptake rate constant of urea with the various sorbents is listed in ascending order: HMW chitosanbased on scanning electron microscopy studies. These results further illustrate the rational design of chitosan-based materials for the controlled uptake of urea in aquatic environments.

  13. A pilot study on mindfulness based stress reduction for smokers

    PubMed Central

    Davis, James M; Fleming, Michael F; Bonus, Katherine A; Baker, Timothy B

    2007-01-01

    Background Mindfulness means paying attention in the present moment, non-judgmentally, without commentary or decision-making. We report results of a pilot study designed to test the feasibility of using Mindfulness Based Stress Reduction (MBSR) (with minor modifications) as a smoking intervention. Methods MBSR instructors provided instructions in mindfulness in eight weekly group sessions. Subjects attempted smoking cessation during week seven without pharmacotherapy. Smoking abstinence was tested six weeks after the smoking quit day with carbon monoxide breath test and 7-day smoking calendars. Questionnaires were administered to evaluate changes in stress and affective distress. Results 18 subjects enrolled in the intervention with an average smoking history of 19.9 cigarettes per day for 26.4 years. At the 6-week post-quit visit, 10 of 18 subjects (56%) achieved biologically confirmed 7-day point-prevalent smoking abstinence. Compliance with meditation was positively associated with smoking abstinence and decreases in stress and affective distress. Discussions and conclusion The results of this study suggest that mindfulness training may show promise for smoking cessation and warrants additional study in a larger comparative trial. PMID:17254362

  14. Unintended Pregnancy in Ethiopia: Community Based Cross-Sectional Study

    PubMed Central

    Berta Badi, Martha

    2016-01-01

    Introduction. Unintended pregnancy is defined as a pregnancy which is a sum of mistimed pregnancy (pregnancy wanted at a later time) and unwanted pregnancy (pregnancy which is not wanted at all). Unintended pregnancy is a global public health problem and its sequels are major causes for maternal and neonatal morbidity and mortality with its effect to maternal metal illness as well. Objective. To determine the prevalence and associated factors of unintended pregnancy in Debre Birhan town, northeast of Ethiopia, in 2014. Method. Community based cross-sectional study and questionnaire developed from Ethiopian demographic health survey 2011. Participants were 690 currently pregnant mothers. Association of unintended pregnancy with factors was measured with bivariate and multivariate logistic regressions. Result. In this study unintended pregnancy is found to be 23.5%. Being formerly married and never married, distance to the nearest health facility >80 minutes, gravidity >5, 1-2 parity, and partner disagreement on desired number of children are the variables significantly associated with unintended pregnancy. Conclusion. Significant proportion of unintended pregnancy is found in the study area. To minimize unintended pregnancy concerned bodies should work on the identified factors, so we can minimize maternal and neonatal morbidity and mortality and keep the health of the family specifically and country in general.

  15. Synthesis, characterization and antimicrobial studies of Schiff base complexes

    NASA Astrophysics Data System (ADS)

    Zafar, Hina; Ahmad, Anis; Khan, Asad U.; Khan, Tahir Ali

    2015-10-01

    The Schiff base complexes, MLCl2 [M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized by the template reaction of respective metal ions with 2-acetylpyrrole and 1,3-diaminopropane in 1:2:1 M ratio. The complexes have been characterized by elemental analyses, ESI - mass, NMR (1H and 13C), IR, XRD, electronic and EPR spectral studies, magnetic susceptibility and molar conductance measurements. These studies show that all the complexes have octahedral arrangement around the metal ions. The molar conductance measurements of all the complexes in DMSO indicate their non-electrolytic nature. The complexes were screened for their antibacterial activity in vitro against Gram-positive (Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae) bacteria. Among the metal complexes studied the copper complex [CuLCl2], showed highest antibacterial activity nearly equal to standard drug ciprofloxacin. Other complexes also showed considerable antibacterial activity. The relative order of activity against S. Pyogenes is as Cu(II) > Zn(II) > Co(II) = Fe(II) > Ni(II) and with K. Pneumonia is as Cu(II) > Co(II) > Zn(II) > Fe(II) > Ni(II).

  16. Unintended Pregnancy in Ethiopia: Community Based Cross-Sectional Study

    PubMed Central

    Berta Badi, Martha

    2016-01-01

    Introduction. Unintended pregnancy is defined as a pregnancy which is a sum of mistimed pregnancy (pregnancy wanted at a later time) and unwanted pregnancy (pregnancy which is not wanted at all). Unintended pregnancy is a global public health problem and its sequels are major causes for maternal and neonatal morbidity and mortality with its effect to maternal metal illness as well. Objective. To determine the prevalence and associated factors of unintended pregnancy in Debre Birhan town, northeast of Ethiopia, in 2014. Method. Community based cross-sectional study and questionnaire developed from Ethiopian demographic health survey 2011. Participants were 690 currently pregnant mothers. Association of unintended pregnancy with factors was measured with bivariate and multivariate logistic regressions. Result. In this study unintended pregnancy is found to be 23.5%. Being formerly married and never married, distance to the nearest health facility >80 minutes, gravidity >5, 1-2 parity, and partner disagreement on desired number of children are the variables significantly associated with unintended pregnancy. Conclusion. Significant proportion of unintended pregnancy is found in the study area. To minimize unintended pregnancy concerned bodies should work on the identified factors, so we can minimize maternal and neonatal morbidity and mortality and keep the health of the family specifically and country in general. PMID:27656213

  17. Unintended Pregnancy in Ethiopia: Community Based Cross-Sectional Study.

    PubMed

    Getu Melese, Kidest; Gebrie, Mignote Hailu; Berta Badi, Martha; Fekadu Mersha, Wubalem

    2016-01-01

    Introduction. Unintended pregnancy is defined as a pregnancy which is a sum of mistimed pregnancy (pregnancy wanted at a later time) and unwanted pregnancy (pregnancy which is not wanted at all). Unintended pregnancy is a global public health problem and its sequels are major causes for maternal and neonatal morbidity and mortality with its effect to maternal metal illness as well. Objective. To determine the prevalence and associated factors of unintended pregnancy in Debre Birhan town, northeast of Ethiopia, in 2014. Method. Community based cross-sectional study and questionnaire developed from Ethiopian demographic health survey 2011. Participants were 690 currently pregnant mothers. Association of unintended pregnancy with factors was measured with bivariate and multivariate logistic regressions. Result. In this study unintended pregnancy is found to be 23.5%. Being formerly married and never married, distance to the nearest health facility >80 minutes, gravidity >5, 1-2 parity, and partner disagreement on desired number of children are the variables significantly associated with unintended pregnancy. Conclusion. Significant proportion of unintended pregnancy is found in the study area. To minimize unintended pregnancy concerned bodies should work on the identified factors, so we can minimize maternal and neonatal morbidity and mortality and keep the health of the family specifically and country in general. PMID:27656213

  18. Ground Based Studies of Thermocapillary Flows in Levitated Drops

    NASA Technical Reports Server (NTRS)

    Sadhal, Satwindar Singh; Trinh, Eugene H.

    1996-01-01

    Ground-based experiments together with analytical studies are presently being conducted for levitated drops. Both acoustic and electrostatic techniques are being employed to achieve levitation of drops in a gaseous environment. The scientific effort is principally on the thermal and the fluid phenomena associated with the local heating of levitated drops, both at 1-g and at low-g. In particular, the thermocapillary flow associated with local spot heating is being studied. Fairly stable acoustic levitation of drops has been achieved with some exceptions when random rotational motion of the drop persists. The flow visualization has been carried out by light scattering from smoke particles for the exterior flow and fluorescent tracer particles in the drop. The results indicate a lack of axial symmetry in the internal flow even though the apparatus and the heating are symmetric. The theoretical studies for the past year have included fundamental analyses of acoustically levitated spherical drops. The flow associated with a particle near the velocity antinode is being investigated by the singular perturbation technique. As a first step towards understanding the effect of the particle displacement from the antinode, the flow field about the node has been calculated for the first time. The effect of the acoustic field on the interior of a liquid drop has also been investigated. The results predict that the internal flow field is very weak.

  19. A study of trends and techniques for space base electronics

    NASA Technical Reports Server (NTRS)

    Trotter, J. D.; Wade, T. E.; Gassaway, J. D.; Mahmood, Q.

    1978-01-01

    A sputtering system was developed to deposit aluminum and aluminum alloys by the dc sputtering technique. This system is designed for a high level of cleanliness and for monitoring the deposition parameters during film preparation. This system is now ready for studying the deposition and annealing parameters upon double-level metal preparation. A technique recently applied for semiconductor analysis, the finite element method, was studied for use in the computer modeling of two dimensional MOS transistor structures. It was concluded that the method has not been sufficiently well developed for confident use at this time. An algorithm was developed for confident use at this time. An algorithm was developed for implementing a computer study which is based upon the finite difference method. The program which was developed was modified and used to calculate redistribution data for boron and phosphorous which had been predeposited by ion implantation with range and straggle conditions. Data were generated for 111 oriented SOS films with redistribution in N2, dry O2 and steam ambients.

  20. Study of Mare Moscoviense based on orbital NIR hyperspectral data

    NASA Astrophysics Data System (ADS)

    Bhatt, Megha; Wöhler, Christian; Bhardwaj, Anil; Mall, Urs; Grumpe, Arne; Rommel, Daniela

    2016-07-01

    The Moscoviense basin is an important lunar farside impact basin. Previous studies of this region suggest compositional variations across the mare basalts, and significant positive gravity anomaly within the basin [1, 2]. In the highlands immediately west of the mare regions inside the Moscoviense basin, unusual spectral signatures indicating small deposits of orthopyroxene, olivine and spinel have been detected [3]. A detailed study of the Moscoviense basin thus allows for an examination of lunar farside highland materials and mare basalts of varying composition and age, providing insights into the lunar mantle composition and magmatic history. We present a geological study of Mare Moscoviense based on near-infrared high-resolution hyperspectral data obtained by the Moon Mineralogy Mapper (M3) [4] and the near-infrared spectrometer, SIR-2 [5]. An M3 reflectance mosaic of the region has been prepared after applying corrections for thermal emission and topography. Two SIR-2 orbits recorded from 100 km spacecraft altitude have also been used for mineralogical study of the region. Elemental abundance maps of Ti, Ca and Mg as well as a petrologic map have been prepared based on the method described in [6]. Furthermore, we utilized the three different algorithms described in [6, 7, 8] for estimating Fe abundances using the 1-µm and/or 2-µm absorption band parameters. This comparative study aims to identify and map the major morphological and compositional units within the Mare Moscoviense region. References: [1] Gillis et al. (1998) Ph.D. thesis, 248 pp., Rice Univ., Houston, Texas; [2] Kramer et al. (2008) JGR 113, E01002, doi:10.1029/2006JE002860; [3] Pieters et al. (2011) JGR 116, E00G08, doi:10.1029/2010JE003727; [4] Pieters C. M. et al. (2009) Current Science 96, 500-505; [5] Mall, U. et al. (2009) Current Science 96, 506-511; [6] Wöhler C. et al. (2014) Icarus 235, 86-122; [7] Lucey P. G. et al. (2000) JGR 105, 20297-20306; [8] Bhatt M. et al. (2015) Icarus 248

  1. Young adults' trajectories of Ecstasy use: a population based study.

    PubMed

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns.

  2. Young adults' trajectories of Ecstasy use: a population based study.

    PubMed

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns. PMID:23899430

  3. Recruitment for a community-based study of early pregnancy: the Right From The Start study.

    PubMed

    Promislow, Joanne H E; Makarushka, Christina M; Gorman, Jessica R; Howards, Penelope P; Savitz, David A; Hartmann, Katherine E

    2004-03-01

    Despite the high incidence of spontaneous abortion, little is known about its causes, in part because of the challenge of assembling a large cohort of women in early pregnancy for prospective study. We describe the effectiveness of recruitment strategies used in Right From The Start (RFTS), a prospective, community-based study of spontaneous abortion. Between December 2000 and September 2002, 803 pregnant women enrolled in RFTS, 103 of whom were recruited while trying to conceive. The mean gestational age at enrollment was 52 days, with 25% of the cohort enrolling before 6 completed weeks' gestation. Participants recruited directly from the community typically enrolled earlier in their pregnancies (mean of 44 days) and accounted for 24% of the total cohort and 83% of all participants who were recruited while trying to conceive. Posting brochures in drug stores and targeted mailings to new homeowners were the most effective community recruitment strategies. Recruitment at private and public prenatal care sites accounted for 57% and 19% of the participants respectively. Recruitment from public clinics required direct contact by RFTS staff and yielded women who enrolled at later gestational ages (mean of 58 days), but was valuable for inclusion of minorities and lower income women with less favourable health behaviours. Although intensive, diverse efforts were required, when recruitment efforts were maximised, we successfully recruited over 10% of the estimated number of pregnant women in the community.

  4. Biologically based epidemiological studies of electric power and cancer

    SciTech Connect

    Stevens, R.G.

    1993-12-01

    Use of electricity is a hallmark of the industrialization process, but there has been no suspicion that electricity could increase the risk of cancer. Recently, however, a number of epidemiologic studies have suggested that electromagnetic fields (EMF) may do just that. Although few cancer experiments have been done yet, there are a number of biological effects of EMF reported in the literature that might provide bases for designing cancer experiments and epidemiologic studies. These include effects of EMF on: (a) DNA transcription and translation, (b) calcium balance in cells, and (c) pineal production of melatonin. Alterations in DNA transcription and translation could have pleiotropic effects. Disruption of calcium homeostasis has many implications including oncogene activation, promotional activity via protein kinases and ornithine decarboxylase (ODC), and increasing oxidative stress. Reduction of melatonin suggests a possible increased risk of cancers of hormone-dependent tissues such as breast and prostate. The idea that a cancer-causing agent must either be an initiator or a promoter should be discarded; indeed, the phenomenologic meaning of these two terms has become confused with imputed mechanistic necessity in recent years. Agents that affect division of normal cells or of fully transformed cells can play an important role in clinical cancer development quite apart from initiation or promotion. Epidemiologic studies of EMF and cancer should attempt to take account of other products of electric power (e.g., light at night) or factors associated with occupational EMF exposure (e.g., toxic chemicals) that may increase cancer risk and therefore act as cofactors or confounders. Epidemiology and laboratory studies should act synergistically in determining if there is a problem and identifying mitigation strategies if needed. 84 refs., 3 figs., 1 tab.

  5. Sitewide feasibility study Eielson Air Force Base, Alaska

    SciTech Connect

    Last, G.V.; Lanigan, D.C.; Josephson, G.B.; Bagaasen, L.M.

    1995-09-01

    The Sitewide Feasibility Study (FS) is required under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the National Contingency Plan (NCP), and the Federal Facility Agreement (FFA) for Eielson Air Force Base (AFB). It is based on findings presented in the Sitewide Remedial Investigation (RI) Report (USAF 1995a), and the Sitewide Baseline Risk Assessment (BLRA) Report (USAF 1995b). Under the FFA, 64 potential source areas were placed in one of six operable units, based on similar contaminant and environmental characteristics, or were included for evaluation under a Source Evaluation Report (SER). The sitewide RI was directed at contamination that was not confined to an operable unit (OU) or SER source area. The objectives of the sitewide RI were to: Provide information about site characteristics to support individual OU RI/FS efforts and the sitewide RI/FS, including site hydrogeology and determination of background soil and groundwater characteristics; identify and characterize contamination that is not confined or attributable to a specific source area through sitewide monitoring of groundwater and surface water; evaluate cumulative risks to human health and the environment from contamination on a sitewide basis; and provide a mechanism for continued cohesive sitewide monitoring.

  6. Memristor crossbar-based neuromorphic computing system: a case study.

    PubMed

    Hu, Miao; Li, Hai; Chen, Yiran; Wu, Qing; Rose, Garrett S; Linderman, Richard W

    2014-10-01

    By mimicking the highly parallel biological systems, neuromorphic hardware provides the capability of information processing within a compact and energy-efficient platform. However, traditional Von Neumann architecture and the limited signal connections have severely constrained the scalability and performance of such hardware implementations. Recently, many research efforts have been investigated in utilizing the latest discovered memristors in neuromorphic systems due to the similarity of memristors to biological synapses. In this paper, we explore the potential of a memristor crossbar array that functions as an autoassociative memory and apply it to brain-state-in-a-box (BSB) neural networks. Especially, the recall and training functions of a multianswer character recognition process based on the BSB model are studied. The robustness of the BSB circuit is analyzed and evaluated based on extensive Monte Carlo simulations, considering input defects, process variations, and electrical fluctuations. The results show that the hardware-based training scheme proposed in the paper can alleviate and even cancel out the majority of the noise issue.

  7. Synthesis and study of novel silicon-based unsaturated polymers

    SciTech Connect

    Lin, J.

    1995-06-19

    Novel unsaturated polymers have been synthesized and studied as precursors to silicon carbide and third order nonlinear optical materials. X ray structures were obtained. Kinetic and mechanistic studies of the unique thermal isomerization of dimethylenedisilacyclobutane to a carbene were conducted.

  8. Instructor Based Training Versus Computer Based Training--A Comparative Study

    ERIC Educational Resources Information Center

    Malmskold, Lennart; Ortengren, Roland; Carlson, Blair E.; Nylen, Per

    2007-01-01

    This article describes two studies conducted to compare assembly performance and learning rate between computer based training and traditional training of skilled assembly operators. The studies were performed with pre-series production parts from a car cockpit and they were integrated as part of the overall training activities during a new…

  9. Study design in evidence-based surgery: What is the role of case-control studies?

    PubMed Central

    Cao, Amy M; Cox, Michael R; Eslick, Guy D

    2016-01-01

    Randomized controlled trials (RCTs) are the gold standard in terms of study design, however, in the surgical setting conducting RCTs can often be unethical or logistically impossible. Case-control studies should become the major study design used in surgical research when RCTs are unable to be conducted and definitely replacing case series which offer little insight into surgical outcomes and disease processes. PMID:27019801

  10. A Study of Central Auction Based Wholesale Electricity Markets

    NASA Astrophysics Data System (ADS)

    Ceppi, Sofia; Gatti, Nicola

    The deregulation of electricity markets produced significant economic benefits, reducing prices to customers and opening several opportunities for new actors, e.g., new generators and distributors. A prominent scientific and technological challenge is the automation of such markets. In particular, we focus our attention on wholesale electricity markets based on a central auction. In these markets, generators sell electricity by means of a central auction to a public authority. Instead, the distribution of electricity to customers takes part in retail markets. The main works presented in the literature model wholesale markets as oligopolies, neglecting thus the specific auction mechanism. In this paper, we enrich these models by introducing an auction mechanism shaped on that used in the Italian wholesale electricity market, we solve the winner determination problem, and we preliminarily study the problem of searching for equilibria.

  11. Behavioral Modeling Based on Probabilistic Finite Automata: An Empirical Study.

    PubMed

    Tîrnăucă, Cristina; Montaña, José L; Ontañón, Santiago; González, Avelino J; Pardo, Luis M

    2016-01-01

    Imagine an agent that performs tasks according to different strategies. The goal of Behavioral Recognition (BR) is to identify which of the available strategies is the one being used by the agent, by simply observing the agent's actions and the environmental conditions during a certain period of time. The goal of Behavioral Cloning (BC) is more ambitious. In this last case, the learner must be able to build a model of the behavior of the agent. In both settings, the only assumption is that the learner has access to a training set that contains instances of observed behavioral traces for each available strategy. This paper studies a machine learning approach based on Probabilistic Finite Automata (PFAs), capable of achieving both the recognition and cloning tasks. We evaluate the performance of PFAs in the context of a simulated learning environment (in this case, a virtual Roomba vacuum cleaner robot), and compare it with a collection of other machine learning approaches. PMID:27347956

  12. Knowledge-based generalization of metabolic networks: a practical study.

    PubMed

    Zhukova, Anna; Sherman, David J

    2014-04-01

    The complex process of genome-scale metabolic network reconstruction involves semi-automatic reaction inference, analysis, and refinement through curation by human experts. Unfortunately, decisions by experts are hampered by the complexity of the network, which can mask errors in the inferred network. In order to aid an expert in making sense out of the thousands of reactions in the organism's metabolism, we developed a method for knowledge-based generalization that provides a higher-level view of the network, highlighting the particularities and essential structure, while hiding the details. In this study, we show the application of this generalization method to 1,286 metabolic networks of organisms in Path2Models that describe fatty acid metabolism. We compare the generalised networks and show that we successfully highlight the aspects that are important for their curation and comparison. PMID:24712528

  13. Study of Flapping Flight Using Discrete Vortex Method Based Simulations

    NASA Astrophysics Data System (ADS)

    Devranjan, S.; Jalikop, Shreyas V.; Sreenivas, K. R.

    2013-12-01

    In recent times, research in the area of flapping flight has attracted renewed interest with an endeavor to use this mechanism in Micro Air vehicles (MAVs). For a sustained and high-endurance flight, having larger payload carrying capacity we need to identify a simple and efficient flapping-kinematics. In this paper, we have used flow visualizations and Discrete Vortex Method (DVM) based simulations for the study of flapping flight. Our results highlight that simple flapping kinematics with down-stroke period (tD) shorter than the upstroke period (tU) would produce a sustained lift. We have identified optimal asymmetry ratio (Ar = tD/tU), for which flapping-wings will produce maximum lift and find that introducing optimal wing flexibility will further enhances the lift.

  14. Computational Study of Monosubstituted Azo(tetrazolepentazolium)-Based Ionic Dimers.

    PubMed

    Pimienta, Ian S O

    2015-06-01

    The structures of monosubstituted azo(tetrazolepentazolium) cations (N11CHR(+)), oxygen-rich anions such as N(NO2)2(-), NO3(-), and ClO4(-), and the corresponding ion pairs are investigated using ab initio quantum chemistry calculations. The substituents (R) used are H, F, CH3, CN, NH2, OH, OCH3, N3, NF2, and C2H3. The stability of the protonated cation is explored by examining the decomposition pathway of the protonated cation (N11CH2(+)) to yield molecular N2 fragments. The heats of formation of these cations, which are based on isodesmic (bond type conserving) reactions, are dependent on the nature of the substituents. Ionic dimer structures are obtained, but side reactions including proton transfer, binding, and hydrogen bonding are observed in the gas phase. Implicit solvation studies are performed to determine the solution properties of the ion pairs.

  15. Study of nanocomposites based on iron oxides and pectin

    NASA Astrophysics Data System (ADS)

    Chistyakova, Nataliya I.; Shapkin, Alexey A.; Sirazhdinov, Ruslan R.; Gubaidulina, Tatiana V.; Kiseleva, Tatiana Yu.; Kazakov, Alexander P.; Rusakov, Vyacheslav S.

    2014-10-01

    Mössbauer and X-ray diffraction study of nanocomposites based on iron oxides and pectin (PC) was carried out involving magnetization measurements. The concentrations of PC in nanocomposites varied from 0 to 10%. Mössbauer investigations of nanocomposites were carried out in the temperature range from 5 to 300 K. Many-state superparamagnetic relaxation model was used for spectra fitting. The magnetization, M(T,H), was measured in the temperature interval of 80-300 K and magnetic field up to 10 kOe. Formation of the "iron-polymer" interface was not observed. Particle sizes were estimated using the Mössbauer and X-ray powder diffraction data.

  16. Study of nanocomposites based on iron oxides and pectin

    SciTech Connect

    Chistyakova, Nataliya I. Shapkin, Alexey A. Sirazhdinov, Ruslan R. Gubaidulina, Tatiana V. Kiseleva, Tatiana Yu. Kazakov, Alexander P. Rusakov, Vyacheslav S.

    2014-10-27

    Mössbauer and X-ray diffraction study of nanocomposites based on iron oxides and pectin (PC) was carried out involving magnetization measurements. The concentrations of PC in nanocomposites varied from 0 to 10%. Mössbauer investigations of nanocomposites were carried out in the temperature range from 5 to 300 K. Many-state superparamagnetic relaxation model was used for spectra fitting. The magnetization, M(T,H), was measured in the temperature interval of 80-300 K and magnetic field up to 10 kOe. Formation of the 'iron-polymer' interface was not observed. Particle sizes were estimated using the Mössbauer and X-ray powder diffraction data.

  17. Study of a gold-foil-based multisphere neutron spectrometer.

    PubMed

    Wang, Z; Hutchinson, J D; Hertel, N E; Burgett, E; Howell, R M

    2008-01-01

    Multisphere neutron spectrometers with active thermal neutron detectors cannot be used in high-intensity radiation fields due to pulse pile-up and dead-time effects. Thus, a multisphere spectrometer using a passive detection system, specifically gold foils, has been investigated in this work. The responses of a gold-foil-based Bonner sphere neutron spectrometer were studied for two different gold-foil holder designs; an aluminium-polyethylene holder and a polyethylene holder. The responses of the two designs were calculated for four incident neutron beam directions, namely, parallel, perpendicular and at +/-45 degrees relative to the flat surface of the foil. It was found that the use of polyethylene holder resulted in a more isotropic response to neutrons for the four incident directions considered. The computed responses were verified by measuring the neutron spectrum of a 252Cf source with known strength.

  18. Knowledge-based generalization of metabolic networks: a practical study.

    PubMed

    Zhukova, Anna; Sherman, David J

    2014-04-01

    The complex process of genome-scale metabolic network reconstruction involves semi-automatic reaction inference, analysis, and refinement through curation by human experts. Unfortunately, decisions by experts are hampered by the complexity of the network, which can mask errors in the inferred network. In order to aid an expert in making sense out of the thousands of reactions in the organism's metabolism, we developed a method for knowledge-based generalization that provides a higher-level view of the network, highlighting the particularities and essential structure, while hiding the details. In this study, we show the application of this generalization method to 1,286 metabolic networks of organisms in Path2Models that describe fatty acid metabolism. We compare the generalised networks and show that we successfully highlight the aspects that are important for their curation and comparison.

  19. Predictors of Childhood Anxiety: A Population-Based Cohort Study

    PubMed Central

    2015-01-01

    Background Few studies have explored predictors of early childhood anxiety. Objective To determine the prenatal, postnatal, and early life predictors of childhood anxiety by age 5. Methods Population-based, provincial administrative data (N = 19,316) from Manitoba, Canada were used to determine the association between demographic, obstetrical, psychosocial, medical, behavioral, and infant factors on childhood anxiety. Results Risk factors for childhood anxiety by age 5 included maternal psychological distress from birth to 12 months and 13 months to 5 years post-delivery and an infant 5-minute Apgar score of ≤7. Factors associated with decreased risk included maternal age < 20 years, multiparity, and preterm birth. Conclusion Identifying predictors of childhood anxiety is a key step to early detection and prevention. Maternal psychological distress is an early, modifiable risk factor. Future research should aim to disentangle early life influences on childhood anxiety occurring in the prenatal, postnatal, and early childhood periods. PMID:26158268

  20. Sensitivity studies for a space-based methane lidar mission

    NASA Astrophysics Data System (ADS)

    Kiemle, C.; Quatrevalet, M.; Ehret, G.; Amediek, A.; Fix, A.; Wirth, M.

    2011-10-01

    Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA) lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN) on a small satellite in polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1% over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol layers and thin

  1. Sensitivity studies for a space-based methane lidar mission

    NASA Astrophysics Data System (ADS)

    Kiemle, C.; Quatrevalet, M.; Ehret, G.; Amediek, A.; Fix, A.; Wirth, M.

    2011-06-01

    Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA) lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN) on a small satellite in Polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1 % over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol layers and thin

  2. Field-based study of connectivity in an agricultural catchment

    NASA Astrophysics Data System (ADS)

    Lexartza-Artza, I.; Wainwright, J.

    2009-12-01

    Field-based studies of hydrological connectivity can provide context-specific knowledge that might both help understand dynamic complex systems and contribute to other synthetic or modelling approaches. The importance of such an understanding of catchment processes and also of the knowledge of catchment connections with water bodies and the changes of concentration with scale for Integrated Catchment Management has been increasingly emphasized. To provide a holistic understanding, approaches to the study of connectivity need to include both structural and functional aspects of the system and must consider the processes taking place within and across different temporal and spatial scales. A semi-quantitative nested approach has been used to investigate connectivity and study the interactions and feedbacks between the factors influencing transfer processes in the Ingbirchworth Catchment, in the uplands of the River Don, England. A series of reconnaissance techniques have been combined with monitoring of aspects such as rainfall, runoff, sediment transfer and soil-moisture distribution from plot to catchment scale and with consideration of linkages between land and water bodies. The temporal aspect has also been considered, with a special focus on the temporal distribution of events and the influence of longer term catchment changes such as those in land use and management practices. A variability of responses has been observed in relation to the characteristics of events, land use and scale of observation, with elements traditionally considered as limiting or enhancing connectivity responding differently under changing conditions. Sediment redistribution, reshaping of structure and consequent reinforcing loops can be observed across all land uses and landscape units, but the relevance it terms of effective connectivity of highly connected patches varies as the scale is increased. The knowledge acquired can contribute to recognise emerging processes significant for

  3. Source mask optimization study based on latest Nikon immersion scanner

    NASA Astrophysics Data System (ADS)

    Zhu, Jun; Wei, Fang; Chen, Lijun; Zhang, Chenming; Zhang, Wei; Nishinaga, Hisashi; El-Sewefy, Omar; Gao, Gen-Sheng; Lafferty, Neal; Meiring, Jason; Zhang, Recoo; Zhu, Cynthia

    2016-03-01

    The 2x nm logic foundry node has many challenges since critical levels are pushed close to the limits of low k1 ArF water immersion lithography. For these levels, improvements in lithographic performance can translate to decreased rework and increased yield. Source Mask Optimization (SMO) is one such route to realize these image fidelity improvements. During SMO, critical layout constructs are intensively optimized in both the mask and source domain, resulting in a solution for maximum lithographic entitlement. From the hardware side, advances in source technology have enabled free-form illumination. The approach allows highly customized illumination, enabling the practical application of SMO sources. The customized illumination sources can be adjusted for maximum versatility. In this paper, we present a study on a critical layer of an advanced foundry logic node using the latest ILT based SMO software, paired with state-of-the-art scanner hardware and intelligent illuminator. Performance of the layer's existing POR source is compared with the ideal SMO result and the installed source as realized on the intelligent illuminator of an NSR-S630D scanner. Both simulation and on-silicon measurements are used to confirm that the performance of the studied layer meets established specifications.

  4. A comparative study of satellite and ground-based phenology.

    PubMed

    Studer, S; Stöckli, R; Appenzeller, C; Vidale, P L

    2007-05-01

    Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.

  5. Synthesis, structural and fungicidal studies of hydrazone based coordination compounds

    NASA Astrophysics Data System (ADS)

    Sharma, Amit Kumar; Chandra, Sulekh

    2013-02-01

    The coordination compounds of the Co(II), Ni(II) and Cu(II) metal ions derived from imine based ligand, benzil bis(carbohydarzone) were structurally and pharmaceutically studied. The compounds have the general stoichiometry [M(L)]X2 and [Co(L)X2], where M = Ni(II) and Cu(II), and X=NO3- and Cl- ions. The analytical techniques like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV/Visible, NMR, ESI mass and EPR were used to study the compounds. The key IR bands, i.e., amide I, amide II and amide III stretching vibrations accounts for the tetradentate metal binding nature of the ligand. The electronic and EPR spectral results suggest the square planar Ni(II) and Cu(II) complexes (giso = 2.11-2.22) and tetragonal geometry Co(II) complexes (giso = 2.10-2.17). To explore the compounds in the biological field, they were examined against the opportunistic pathogens, i.e., Alternaria brassicae, Aspergillus niger and Fusarium oxysporum. The partial covalent character of metal-ligand bond is supported by the orbital reduction factor k (0.62-0.92) and nephalauxetic parameter β (0.55-0.57).

  6. Space-based solar power conversion and delivery systems study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Even at reduced rates of growth, the demand for electric power is expected to more than triple between now and 1995, and to triple again over the period 1995-2020. Without the development of new power sources and advanced transmission technologies, it may not be possible to supply electric energy at prices that are conductive to generalized economic welfare. Solar power is renewable and its conversion and transmission from space may be advantageous. The goal of this study is to assess the economic merit of space-based photovoltaic systems for power generation and a power relay satellite for power transmission. In this study, satellite solar power generation and transmission systems, as represented by current configurations of the Satellite Solar Station (SSPS) and the Power Relay Satellite (PRS), are compared with current and future terrestrial power generation and transmission systems to determine their technical and economic suitability for meeting power demands in the period of 1990 and beyond while meeting ever-increasing environmental and social constraints.

  7. Gender-based education during clerkships: a focus group study

    PubMed Central

    van Leerdam, Lotte; Rietveld, Lianne; Teunissen, Doreth; Lagro-Janssen, Antoine

    2014-01-01

    Objectives One of the goals of the medical master’s degree is for a student to become a gender-sensitive doctor by applying knowledge of gender differences in practice. This study aims to investigate, from the students’ perspective, whether gender medicine has been taught in daily practice during clerkship. Methods A focus group study was conducted among 29 medical students from Radboud University, Nijmegen, The Netherlands, who had just finished either their internal medicine or surgical clerkships. Data were analyzed in line with the principles of constant comparative analysis. Results Four focus groups were conducted with 29 participating students. Clinical teachers barely discuss gender differences during students’ clerkships. The students mentioned three main explanatory themes: insufficient knowledge; unawareness; and minor impact. As a result, students feel that they have insufficient competencies to become gender-sensitive doctors. Conclusion Medical students at our institution perceive that they have received limited exposure to gender-based education after completing two key clinical clerkships. All students feel that they have insufficient knowledge to become gender-sensitive doctors. They suppose that their clinical teachers have insufficient knowledge regarding gender sensitivity, are unaware of gender differences, and the students had the impression that gender is not regarded as an important issue. We suggest that the medical faculty should encourage clinical teachers to improve their knowledge and awareness of gender issues. PMID:24600301

  8. Multiplex component-based allergen microarray in recent clinical studies.

    PubMed

    Patelis, A; Borres, M P; Kober, A; Berthold, M

    2016-08-01

    During the last decades component-resolved diagnostics either as singleplex or multiplex measurements has been introduced into the field of clinical allergology, providing important information that cannot be obtained from extract-based tests. Here we review recent studies that demonstrate clinical applications of the multiplex microarray technique in the diagnosis and risk assessment of allergic patients, and its usefulness in studies of allergic diseases. The usefulness of ImmunoCAP ISAC has been validated in a wide spectrum of allergic diseases like asthma, allergic rhinoconjunctivitis, atopic dermatitis, eosinophilic esophagitis, food allergy and anaphylaxis. ISAC provides a broad picture of a patient's sensitization profile from a single test, and provides information on specific and cross-reactive sensitizations that facilitate diagnosis, risk assessment, and disease management. Furthermore, it can reveal unexpected sensitizations which may explain anaphylaxis previously categorized as idiopathic and also display for the moment clinically non-relevant sensitizations. ISAC can facilitate a better selection of relevant allergens for immunotherapy compared with extract testing. Microarray technique can visualize the allergic march and molecular spreading in the preclinical stages of allergic diseases, and may indicate that the likelihood of developing symptomatic allergy is associated with specific profiles of sensitization to allergen components. ISAC is shown to be a useful tool in routine allergy diagnostics due to its ability to improve risk assessment, to better select relevant allergens for immunotherapy as well as detecting unknown sensitization. Multiplex component testing is especially suitable for patients with complex symptomatology. PMID:27196983

  9. A Web-based Geovisual Analytical System for Climate Studies

    NASA Astrophysics Data System (ADS)

    Sun, M.; Li, J.; Yang, C.; Schmidt, G. A.; Bambacus, M.; Cahalan, R.; Huang, Q.; Xu, C.; Noble, E.

    2012-12-01

    Climate studies involve petabytes of spatiotemporal datasets that are produced and archived at distributed computing resources. Scientists need an intuitive and convenient tool to explore the distributed spatiotemporal data. Geovisual analytical tools have the potential to provide such an intuitive and convenient method for scientists to access climate data, discover the relationships between various climate parameters, and communicate the results across different research communities. However, implementing a geovisual analytical tool for complex climate data in a distributed environment poses several challenges. This paper reports our efforts in developing a web-based geovisual analytical system to support the analysis of climate data generated by Intergovernmental Panel on Climate Change (IPCC), Fourth Assessment Report (AR4) models. Using the ModelE developed by NASA Goddard Institute for Space Studies (GISS) as an example, we demonstrate that the system is able to 1) manage large volume datasets over the Internet, 2) visualize 3D/4D spatiotemporal data, 3) broker various spatiotemporal statistical analyses for climate research, and 4) support interactive data analysis and knowledge discovery. This research also provides an example of how to manage, disseminate, and analyze Big Data in the 21st century.

  10. Men's health: a population-based study on social inequalities.

    PubMed

    Bastos, Tássia Fraga; Alves, Maria Cecília Goi Porto; Barros, Marilisa Berti de Azevedo; Cesar, Chester Luiz Galvão

    2012-11-01

    This study evaluates social inequalities in health according to level of schooling in the male population. This was a cross-sectional, population-based study with a sample of 449 men ranging from 20 to 59 years of age and living in Campinas, São Paulo State, Brazil. The chi-square test was used to verify associations, and a Poisson regression model was used to estimate crude and adjusted prevalence ratios. Men with less schooling showed higher rates of alcohol consumption and dependence, smoking, sedentary lifestyle during leisure time, and less healthy eating habits, in addition to higher prevalence of bad or very bad self-rated health, at least one chronic disease, hypertension, and other health problems. No differences were detected between the two schooling strata in terms of use of health services, except for dental services. The findings point to social inequality in health-related behaviors and in some health status indicators. However, possible equity was observed in the use of nearly all types of health services.

  11. Study of the Topological-insulator-based Topological Superconductors

    NASA Astrophysics Data System (ADS)

    Qian, Dong

    Three-dimensional topological insulators possess nontrivial spin-momentum locked surface states under the protection of time-reversal symmetry. The interplay between topological order and superconductivity can lead to topological superconducting state. In this talk, I will discuss our recent progress in topological-insulator-based topological superconductors. Using molecular beam epitaxy (MBE) method, we succeeded in fabricating very high quality TI/s-wave superconductor heterostructure by growing topological insulator thin films on the conventional superconductor niobium diselenide (NbSe2) substrate. Using low temperature scanning tunneling microscopy/spectroscopy (STM/STS) and angle-resolved photoemission spectroscopy (ARPES), we systematically studied its electronic structure and superconducting behavior. Through superconducting proximity effect, coexistence of Cooper pairs and topological surface states on the surface of topological insulator film was realized. By exploring the superconducting vortex core state as the function of film thickness, existing of nontrivial superconducting state on the TI's surface was proposed. Our topological insulator/superconductor heterostructure may host single zero-energy Majorana mode in the vortex core. In addition, I will also discuss STM and ARPES studies on the recently discovered superconducting Sr-doped Bi2Se3 bulk crystals. Our results suggest that Sr-doped Bi2Se3 could be an excellent candidate for exploring topological superconducting states. Supported by the Ministry of Science and Technology of China and NSFC.

  12. Synthesis, structural and fungicidal studies of hydrazone based coordination compounds.

    PubMed

    Sharma, Amit Kumar; Chandra, Sulekh

    2013-02-15

    The coordination compounds of the Co(II), Ni(II) and Cu(II) metal ions derived from imine based ligand, benzil bis(carbohydarzone) were structurally and pharmaceutically studied. The compounds have the general stoichiometry [M(L)]X(2) and [Co(L)X(2)], where M=Ni(II) and Cu(II), and X=NO(3)(-) and Cl(-) ions. The analytical techniques like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV/Visible, NMR, ESI mass and EPR were used to study the compounds. The key IR bands, i.e., amide I, amide II and amide III stretching vibrations accounts for the tetradentate metal binding nature of the ligand. The electronic and EPR spectral results suggest the square planar Ni(II) and Cu(II) complexes (g(iso)=2.11-2.22) and tetragonal geometry Co(II) complexes (g(iso)=2.10-2.17). To explore the compounds in the biological field, they were examined against the opportunistic pathogens, i.e., Alternaria brassicae, Aspergillus niger and Fusarium oxysporum. The partial covalent character of metal-ligand bond is supported by the orbital reduction factor k (0.62-0.92) and nephalauxetic parameter β (0.55-0.57).

  13. Results-Based Management for Human Resource Development Projects: The Results-Based Management Study Report.

    ERIC Educational Resources Information Center

    Meier, Werner; And Others

    In response to a growing shift from management by activity to results-based management systems, the Association of Canadian Community Colleges (ACCC) undertook a study to identify issues, expected outcomes, and recommended approaches related to the implementation of a results-based system for the Canadian College Partnership Program (CCPP). Data…

  14. A Population-based study of dementia in the oldest old: the Monzino 80-plus Study

    PubMed Central

    2011-01-01

    Background Despite being the fastest growing and the most cognitively impaired age group, the oldest olds are under-represented in clinical research. The purpose of this study was to describe the design, methods, and baseline characteristics of the survey population and investigate possible differences in demographic, cognitive, functional, and behavioral characteristics between oldest old with and without any performance on cognitive tests and between oldest old alive and those deceased prior to the interview. Methods The Monzino 80-plus Study is a prospective door-to-door population-based survey among 80 years or older residents in the municipalities in the province of Varese, Italy. Dementia cases were identified with a one-phase design. Trained psychologists interviewed both the subject and a proxy informant. The interview included a comprehensive standardized questionnaire together with an array of rating scales and a multidomain cognitive battery to assess cognitive and functional ability, behavioral disturbances and mood. Results Information was available for 2,139 of the 2,428 registered individuals aged 80 years or older. Main baseline characteristics of the population are reported and discussed. In comparison with those living, elderly persons who had died before the first visit were older, had twice the rate of institutionalization, poorer cognitive performance and competence, and significantly greater instrumental and basic functional disability. The percentage of elderly persons, alive at baseline, without Mini-Mental State Examination rose rather evenly with age. Moreover, they had significantly worse cognitive competence and functional ability, and reported higher prevalences of depressive symptoms and problem behaviors than those with Mini-Mental State Examination. Conclusions Prospective investigation of a large population of oldest old can contribute significantly to understanding the relations between age, cognitive decline, and dementia

  15. A population-based study of large granular lymphocyte leukemia

    PubMed Central

    Shah, M V; Hook, C C; Call, T G; Go, R S

    2016-01-01

    Large granular lymphocyte (LGL) leukemia is a lymphoproliferative disorder of cytotoxic cells. T-cell LGL (T-LGL) leukemia is characterized by accumulation of cytotoxic T cells in blood and infiltration of the bone marrow, liver or spleen. Population-based studies have not been reported in LGL leukemia. We present clinical characteristics, natural history and risk factors for poor survival in patients with LGL leukemia using the Surveillance, Epidemiology, and End Results Program (SEER) and the United States National Cancer Data Base (NCDB). LGL leukemia is an extremely rare disease with the incidence of 0.2 cases per 1 000 000 individuals. The median age at diagnosis was 66.5 years with females likely to be diagnosed at 3 years earlier compared with males. Analysis of patient-level data using NCDB (n=978) showed that 45% patients with T-LGL leukemia required some form of systemic treatment at the time of diagnosis. T-LGL leukemia patients have reduced survival compared with general population, with a median overall survival of 9 years. Multivariate analysis showed that age >60 years at the time of diagnosis and the presence of significant comorbidities were independent predictors of poor survival. PMID:27494824

  16. A Basic Study on Cost Based Lot Sizing

    NASA Astrophysics Data System (ADS)

    Sashio, Kentaro; Kaihara, Toshiya; Fujii, Susumu; Inao, Shinya

    To deal with the diversification of consumers' needs and to survive in the severe competitive environment, a grate deal of effort has been paid by manufacturers. Respecting the background, importance of effective lot sizing has been focused. Although variety of lot sizing algorithms has been proposed, most of their objective functions are based on time and quantity criteria. However, it is difficult to select an appropriate criterion universally, because the most important criterion is changed dynamically in real manufacturing environment. Then product cost seems to be a universal criterion, since profit is generally quite important factor in manufacturing enterprises. On the other hand, a concept of Distributed Virtual Factory (DVF) has been proposed as a new simulation environment for evaluating the performance of whole manufacturing systems. By performing simulation with DVF, all the information required to product cost calculation can be obtained. In this study, we propose an effective lot sizing methodology which performs Activity Based Costing (ABC) and minimizes product cost directly. We clarify the validity of the proposed lot sizing method through simulation experiments with DVF.

  17. Electrical studies on silver based fast ion conducting glassy materials

    SciTech Connect

    Rao, B. Appa Kumar, E. Ramesh Kumari, K. Rajani Bhikshamaiah, G.

    2014-04-24

    Among all the available fast ion conductors, silver based glasses exhibit high conductivity. Further, glasses containing silver iodide enhances fast ion conducting behavior at room temperature. Glasses of various compositions of silver based fast ion conductors in the AgI−Ag{sub 2}O−[(1−x)B{sub 2}O{sub 3}−xTeO{sub 2}] (x=0 to1 mol% in steps of 0.2) glassy system have been prepared by melt quenching method. The glassy nature of the compounds has been confirmed by X-ray diffraction. The electrical conductivity (AC) measurements have been carried out in the frequency range of 1 KHz–3MHz by Impedance Analyzer in the temperature range 303–423K. The DC conductivity measurements were also carried out in the temperature range 300–523K. From both AC and DC conductivity studies, it is found that the conductivity increases and activation energy decreases with increasing the concentration of TeO{sub 2} as well as with temperature. The conductivity of the present glass system is found to be of the order of 10{sup −2} S/cm at room temperature. The ionic transport number of these glasses is found to be 0.999 indicating that these glasses can be used as electrolyte in batteries.

  18. Statistical Studies of Ground-Based Optical Lightning Signatures

    NASA Astrophysics Data System (ADS)

    Hunt, C. R.; Nemzek, R. J.; Suszcynsky, D. M.

    2005-12-01

    Most extensive optical studies of lightning have been conducted from orbit, and the statistics of events collected from earth are relatively poorly documented. The time signatures of optical power measured in the presence of clouds are inevitably affected by scattering,which can distort the signatures by extending and delaying the amplitude profile in time. We have deployed two all-sky photodiode detectors, one in New Mexico and one in Oklahoma, which are gathering data alongside electric field change monitors as part of the LANL EDOTX Great Plains Array. Preliminary results show that the photodiode is sensitive to approximately 50% or more of RF events detected at ranges of up to 30 km, and still has some sensitivity at ranges in excess of 60 km (distances determined by the EDOTX field-change array). The shapes of events within this range were assessed, with focus on rise time, width, peak power, and their correlation to corresponding electric field signatures, and these are being compared with published on-orbit and ground-based data. Initial findings suggest a mean characteristic width (ratio of total detected optical energy to peak power) of 291 +/- 12 microseconds and a mean delay between the RF signal peak and optical peak of 121 +/- 17 microseconds. These values fall between prior ground-based measurements of direct return stroke emissions, and scattering-dominated on-orbit measurements. This work will promote better understanding of the correspondence between radio and optical measurements of lightning.

  19. Space-based laser-driven MHD generator: Feasibility study

    NASA Technical Reports Server (NTRS)

    Choi, S. H.

    1986-01-01

    The feasibility of a laser-driven MHD generator, as a candidate receiver for a space-based laser power transmission system, was investigated. On the basis of reasonable parameters obtained in the literature, a model of the laser-driven MHD generator was developed with the assumptions of a steady, turbulent, two-dimensional flow. These assumptions were based on the continuous and steady generation of plasmas by the exposure of the continuous wave laser beam thus inducing a steady back pressure that enables the medium to flow steadily. The model considered here took the turbulent nature of plasmas into account in the two-dimensional geometry of the generator. For these conditions with the plasma parameters defining the thermal conductivity, viscosity, electrical conductivity for the plasma flow, a generator efficiency of 53.3% was calculated. If turbulent effects and nonequilibrium ionization are taken into account, the efficiency is 43.2%. The study shows that the laser-driven MHD system has potential as a laser power receiver for space applications because of its high energy conversion efficiency, high energy density and relatively simple mechanism as compared to other energy conversion cycles.

  20. Secured web-based video repository for multicenter studies

    PubMed Central

    Yan, Ling; Hicks, Matt; Winslow, Korey; Comella, Cynthia; Ludlow, Christy; Jinnah, H. A; Rosen, Ami R; Wright, Laura; Galpern, Wendy R; Perlmutter, Joel S

    2015-01-01

    Background We developed a novel secured web-based dystonia video repository for the Dystonia Coalition, part of the Rare Disease Clinical Research network funded by the Office of Rare Diseases Research and the National Institute of Neurological Disorders and Stroke. A critical component of phenotypic data collection for all projects of the Dystonia Coalition includes a standardized video of each participant. We now describe our method for collecting, serving and securing these videos that is widely applicable to other studies. Methods Each recruiting site uploads standardized videos to a centralized secured server for processing to permit website posting. The streaming technology used to view the videos from the website does not allow downloading of video files. With appropriate institutional review board approval and agreement with the hosting institution, users can search and view selected videos on the website using customizable, permissions-based access that maintains security yet facilitates research and quality control. Results This approach provides a convenient platform for researchers across institutions to evaluate and analyze shared video data. We have applied this methodology for quality control, confirmation of diagnoses, validation of rating scales, and implementation of new research projects. Conclusions We believe our system can be a model for similar projects that require access to common video resources. PMID:25630890

  1. Study on Subspace Control Based on Modal Analysis

    NASA Astrophysics Data System (ADS)

    Sonobe, Motomichi; Kondou, Takahiro; Sowa, Nobuyuki; Matsuzaki, Kenichiro

    As a new control technique called the subspace control method is developed in an effort to carry out finely tuned control easily and efficiently for a complicated and large-scale mechanical system. In the subspace control method, the minimum and optimum subspace suited for the control specification is extracted from the entire state space by applying the concept of modal analysis, and feedback control based on the modal coordinate is performed in the subspace. The subspace control method takes advantage of the dynamic characteristics of the controlled object in the design of control system. In addition, decreasing the dimension of the controlled object based on the dynamic characteristics leads to simplification of the design of control system, reduction of mechanical overload caused by the control, and a reduction in consumed electric power. In the present study, in order to clarify the fundamental concept, the subspace control method is formulated for swing-up and stabilizing controls of an inverted pendulum system. The effectiveness of the proposed method is verified by numerical simulations and experiments.

  2. A Whole-Language Base for Theme Studies in the Social Studies Curriculum.

    ERIC Educational Resources Information Center

    Lamme, Linda Leonard; Hysmith, Cecilia

    1993-01-01

    Asserts that the whole-language approach is a philosophy of learning in which children construct knowledge by actively engaging in classroom projects that have real meaning for them. Describes thematic studies using a whole-language approach in which children (with teacher assistance) decide what themes will be studied. (CFR)

  3. Ablation study of tungsten-based nuclear thermal rocket fuel

    NASA Astrophysics Data System (ADS)

    Smith, Tabitha Elizabeth Rose

    The research described in this thesis has been performed in order to support the materials research and development efforts of NASA Marshall Space Flight Center (MSFC), of Tungsten-based Nuclear Thermal Rocket (NTR) fuel. The NTR was developed to a point of flight readiness nearly six decades ago and has been undergoing gradual modification and upgrading since then. Due to the simplicity in design of the NTR, and also in the modernization of the materials fabrication processes of nuclear fuel since the 1960's, the fuel of the NTR has been upgraded continuously. Tungsten-based fuel is of great interest to the NTR community, seeking to determine its advantages over the Carbide-based fuel of the previous NTR programs. The materials development and fabrication process contains failure testing, which is currently being conducted at MSFC in the form of heating the material externally and internally to replicate operation within the nuclear reactor of the NTR, such as with hot gas and RF coils. In order to expand on these efforts, experiments and computational studies of Tungsten and a Tungsten Zirconium Oxide sample provided by NASA have been conducted for this dissertation within a plasma arc-jet, meant to induce ablation on the material. Mathematical analysis was also conducted, for purposes of verifying experiments and making predictions. The computational method utilizes Anisimov's kinetic method of plasma ablation, including a thermal conduction parameter from the Chapman Enskog expansion of the Maxwell Boltzmann equations, and has been modified to include a tangential velocity component. Experimental data matches that of the computational data, in which plasma ablation at an angle shows nearly half the ablation of plasma ablation at no angle. Fuel failure analysis of two NASA samples post-testing was conducted, and suggestions have been made for future materials fabrication processes. These studies, including the computational kinetic model at an angle and the

  4. Risk-based monitored natural attenuation--a case study.

    PubMed

    Khan, F I; Husain, T

    2001-08-17

    The term "monitored natural attenuation" (MNA) refers to a reliance on natural attenuation (NA) processes for remediation through the careful monitoring of the behavior of a contaminant source in time and space domains. In recent years, policymakers are shifting to a risk-based approach where site characteristics are measured against the potential risk to human health and the environment, and site management strategies are prioritized to be commensurate with that risk. Risk-based corrective action (RBCA), a concept developed by the American Society for Testing Materials (ASTM), was the first indication of how this approach could be used in the development of remediation strategies. This paper, which links ASTM's RBCA approach with MNA, develops a systematic working methodology for a risk-based site evaluation and remediation through NA. The methodology is comprised of seven steps, with the first five steps intended to evaluate site characteristics and the feasibility of NA. If NA is effective, then the last two steps will guide the development of a long-term monitoring plan and approval for a site closure. This methodology is used to evaluate a site contaminated with oil from a pipeline spill. The case study concluded that the site has the requisite characteristics for NA, but it would take more than 80 years for attenuation of xylene and ethylbenzene, as these chemicals appear in the pure phase. If fast remediation is sought, then efforts should be made to remove the contaminant from the soil. Initially, the site posed a serious risk to both on-site and off-site receptors, but it becomes acceptable after 20 years, as the plume is diluted and drifts from its source of origin.

  5. Technology base studies of long-term MCFC performance

    SciTech Connect

    Selman, J.R.

    1995-08-01

    Cathode dissolution into the electrolyte matrix and endurance of current collector/separator plate materials are the main life-limiting factors of the state-of-the art MCFC. These components are also major contributors to the total system cost. Therefore, to reduce capital cost, it is necessary to minimize hardware corrosion and increase cell life. This study consists of experimental evaluation of corrosion processes with the objective to further practical; understanding of corrosion behavior of alloys and alloy components under cathodic gas conditions. Nickel, iron, cobalt and stainless steels 310 and 316L are analyzed. The experimental study consists of (1) Observation of open circuit potential (OCP) changes. Surface reactions occurring without net passage of current are proposed based on this measurement. (2) Applying cyclic voltammetry, which provides information about the possible electrode reactions at different stages of polarization. (3) Applying AC impedance to support the result of tasks 1 and 2 at different stages of oxidation, and data analysis by means of equivalent circuits. Open circuit conditions as well as positive and negative polarization are used in the impedance measurements. (4) Surface analysis of the electrodes by SEM-EDX and X-ray diffraction. To obtain more information from electrochemical measurements a novel approach has been applied in cell design. In this two-electrode approach, one electrode is fully immersed, and the other is wetted by carbonate melt via an alumina tube which has a thin film on it. While camera observation of these two different electrode conditions will identify the effect of carbonate wetting on the state of the surface, electrochemical measurements enable a quantitative comparison between complete submersion and wetting by a film of carbonate.

  6. RP-1 Thermal Stability and Copper Based Materials Compatibility Study

    NASA Technical Reports Server (NTRS)

    Stiegemeier, B. R.; Meyer, M. L.; Driscoll, E.

    2005-01-01

    A series of electrically heated tube tests was performed at the NASA Glenn Research Center s Heated Tube Facility to investigate the effect that sulfur content, test duration, and tube material play in the overall thermal stability and materials compatibility characteristics of RP-1. Scanning-electron microscopic (SEM) analysis in conjunction with energy dispersive spectroscopy (EDS) were used to characterize the condition of the tube inner wall surface and any carbon deposition or corrosion formed during these runs. Results of the parametric study indicate that tests with standard RP-1 (total sulfur -23 ppm) and pure copper tubing are characterized by a depostion/deposit shedding process producing local wall temperature swings as high as 500 F. The effect of this shedding is to keep total carbon deposition levels relatively constant for run times from 20 minutes up to 5 hours, though increasing tube pressure drops were observed in all runs. Reduction in the total sulfur content of the fuel from 23 ppm to less than 0.1 ppm resulted in the elimination of deposit shedding, local wall temperature variation, and the tube pressure drop increases that were observed in standard sulfur level RP-1 tests. The copper alloy GRCop-84, a copper alloy developed specifically for high heat flux applications, was found to exhibit higher carbon deposition levels compared to identical tests performed in pure copper tubes. Results of the study are consistent with previously published heated tube data which indicates that small changes in fuel total sulfur content can lead to significant differences in the thermal stability of kerosene type fuels and their compatibility with copper based materials. In conjunction with the existing thermal stability database, these findings give insight into the feasibility of cooling a long life, high performance, high-pressure liquid rocket combustor and nozzle with RP-1.

  7. Technology base studies of long-term MCFC performance

    SciTech Connect

    Selman, J.R.; Yazici, M.S.

    1995-12-01

    Cathode dissolution into the electrolyte matrix and endurance of current collector/separator plate materials are the main life-limiting factors of the state-of-the art MCFC. These components are also major contributors to the total system cost. Therefore, to reduce capital cost, it is necessary to minimize hardware corrosion and increase cell life. This study consists of experimental evaluation of corrosion processes with the objective to further practical; understanding of corrosion behavior of alloys and alloy components under cathodic gas conditions. Nickel, iron, cobalt and stainless steels 310 and 316L are analyzed. The experimental study consists of: (1) Observation of open circuit potential (OCP) changes. Surface reactions occurring without net passage of current are proposed based on this measurement. (2) Applying cyclic voltammetry, which provides information about the possible electrode reactions at different stages of polarization. (3) Applying AC impedance to support the result of tasks 1 and 2 at different stages of oxidation, and data analysis by means of equivalent circuits. Open circuit conditions as well as positive and negative polarization are used in the impedance measurements. (4) Surface analysis of the electrodes by SEM-EDX and X-ray diffraction. To obtain more information from electrochemical measurements a novel approach has been applied in cell design. In this two electrode approach, one electrode is fully immersed, and the other is wetted by carbonate melt via an alumina tube which has a thin film on it. While camera observation of these two different electrode conditions will identify the effect of carbonate wetting on the state of the surface, electrochemical measurements enable a quantitative comparison between complete submersion and wetting by a film of carbonate.

  8. Gravity wave reflection: Case study based on rocket data

    NASA Astrophysics Data System (ADS)

    Wüst, Sabine; Bittner, Michael

    2008-03-01

    Since gravity waves significantly influence the atmosphere by transporting energy and momentum, it is important to study their wave spectrum and their energy dissipation rates. Besides that, knowledge about gravity wave sources and the propagation of the generated waves is essential. Originating in the lower atmosphere, gravity waves can move upwards; when the background wind field is equal to their phase speed a so-called critical layer is reached. Their breakdown and deposition of energy and momentum is possible. Another mechanism which can take place at critical layers is gravity wave reflection. In this paper, gravity waves which were observed by foil chaff measurements during the DYANA (DYnamics Adapted Network for the Atmosphere) campaign in 1990 in Biscarrosse (44°N, 1°W)--as reported by Wüst and Bittner [2006. Non-linear wave-wave interaction: case studies based on rocket data and first application to satellite data. Journal of Atmospheric and Solar-Terrestrial Physics 68, 959-976]--are investigated to look for gravity wave reflection processes. Following nonlinear theory, energy dissipation rates according to Weinstock [1980. Energy dissipation rates of turbulence in the stable free atmosphere. Journal of the Atmospheric Sciences 38, 880-883] are calculated from foil chaff cloud and falling sphere data and compared with the critical layer heights. Enhanced energy dissipation rates are found at those altitudes where the waves' phase speed matches the zonal background wind speeds. Indication of gravity wave trapping is found between two altitudes of around 95 and 86 km.

  9. Model Based Systems Engineering on the Europa Mission Concept Study

    NASA Technical Reports Server (NTRS)

    Bayer, Todd J.; Chung, Seung; Cole, Bjorn; Cooke, Brian; Dekens, Frank; Delp, Chris; Gontijo, I.; Lewis, Kari; Moshir, Mehrdad; Rasmussen, Robert; Wagner, Dave

    2012-01-01

    At the start of 2011, the proposed Jupiter Europa Orbiter (JEO) mission was staffing up in expectation of becoming an official project later in the year for a launch in 2020. A unique aspect of the pre-project work was a strong emphasis and investment on the foundations of Model-Based Systems Engineering (MBSE). As so often happens in this business, plans changed: NASA's budget and science priorities were released and together fundamentally changed the course of JEO. As a result, it returned to being a study task whose objective is to propose more affordable ways to accomplish the science. As part of this transition, the question arose as to whether it could continue to afford the investment in MBSE. In short, the MBSE infusion has survived and is providing clear value to the study effort. By leveraging the existing infrastructure and a modest additional investment, striking advances in the capture and analysis of designs using MBSE were achieved. In the process, the need to remain relevant in the new environment has brought about a wave of innovation and progress. The effort has reaffirmed the importance of architecting. It has successfully harnessed the synergistic relationship of architecting to system modeling. We have found that MBSE can provide greater agility than traditional methods. We have also found that a diverse 'ecosystem' of modeling tools and languages (SysML, Mathematica, even Excel) is not only viable, but an important enabler of agility and adaptability. This paper will describe the successful application of MBSE in the dynamic environment of early mission formulation, the significant results produced and lessons learned in the process.

  10. Behavior-based safety on construction sites: a case study.

    PubMed

    Choudhry, Rafiq M

    2014-09-01

    This work presents the results of a case study and describes an important area within the field of construction safety management, namely behavior-based safety (BBS). This paper adopts and develops a management approach for safety improvements in construction site environments. A rigorous behavioral safety system and its intervention program was implemented and deployed on target construction sites. After taking a few weeks of safety behavior measurements, the project management team implemented the designed intervention and measurements were taken. Goal-setting sessions were arranged on-site with workers' participation to set realistic and attainable targets of performance. Safety performance measurements continued and the levels of performance and the targets were presented on feedback charts. Supervisors were asked to give workers recognition and praise when they acted safely or improved critical behaviors. Observers were requested to have discussions with workers, visit the site, distribute training materials to workers, and provide feedback to crews and display charts. They were required to talk to operatives in the presence of line managers. It was necessary to develop awareness and understanding of what was being measured. In the process, operatives learned how to act safely when conducting site tasks using the designed checklists. Current weekly scores were discussed in the weekly safety meetings and other operational site meetings with emphasis on how to achieve set targets. The reliability of the safety performance measures taken by the company's observers was monitored. A clear increase in safety performance level was achieved across all categories: personal protective equipment; housekeeping; access to heights; plant and equipment, and scaffolding. The research reveals that scores of safety performance at one project improved from 86% (at the end of 3rd week) to 92.9% during the 9th week. The results of intervention demonstrated large decreases in

  11. Behavior-based safety on construction sites: a case study.

    PubMed

    Choudhry, Rafiq M

    2014-09-01

    This work presents the results of a case study and describes an important area within the field of construction safety management, namely behavior-based safety (BBS). This paper adopts and develops a management approach for safety improvements in construction site environments. A rigorous behavioral safety system and its intervention program was implemented and deployed on target construction sites. After taking a few weeks of safety behavior measurements, the project management team implemented the designed intervention and measurements were taken. Goal-setting sessions were arranged on-site with workers' participation to set realistic and attainable targets of performance. Safety performance measurements continued and the levels of performance and the targets were presented on feedback charts. Supervisors were asked to give workers recognition and praise when they acted safely or improved critical behaviors. Observers were requested to have discussions with workers, visit the site, distribute training materials to workers, and provide feedback to crews and display charts. They were required to talk to operatives in the presence of line managers. It was necessary to develop awareness and understanding of what was being measured. In the process, operatives learned how to act safely when conducting site tasks using the designed checklists. Current weekly scores were discussed in the weekly safety meetings and other operational site meetings with emphasis on how to achieve set targets. The reliability of the safety performance measures taken by the company's observers was monitored. A clear increase in safety performance level was achieved across all categories: personal protective equipment; housekeeping; access to heights; plant and equipment, and scaffolding. The research reveals that scores of safety performance at one project improved from 86% (at the end of 3rd week) to 92.9% during the 9th week. The results of intervention demonstrated large decreases in

  12. Estimating glomerular filtration rate in a population-based study

    PubMed Central

    Shankar, Anoop; Lee, Kristine E; Klein, Barbara EK; Muntner, Paul; Brazy, Peter C; Cruickshanks, Karen J; Nieto, F Javier; Danforth, Lorraine G; Schubert, Carla R; Tsai, Michael Y; Klein, Ronald

    2010-01-01

    Background: Glomerular filtration rate (GFR)-estimating equations are used to determine the prevalence of chronic kidney disease (CKD) in population-based studies. However, it has been suggested that since the commonly used GFR equations were originally developed from samples of patients with CKD, they underestimate GFR in healthy populations. Few studies have made side-by-side comparisons of the effect of various estimating equations on the prevalence estimates of CKD in a general population sample. Patients and methods: We examined a population-based sample comprising adults from Wisconsin (age, 43–86 years; 56% women). We compared the prevalence of CKD, defined as a GFR of <60 mL/min per 1.73 m2 estimated from serum creatinine, by applying various commonly used equations including the modification of diet in renal disease (MDRD) equation, Cockcroft–Gault (CG) equation, and the Mayo equation. We compared the performance of these equations against the CKD definition of cystatin C >1.23 mg/L. Results: We found that the prevalence of CKD varied widely among different GFR equations. Although the prevalence of CKD was 17.2% with the MDRD equation and 16.5% with the CG equation, it was only 4.8% with the Mayo equation. Only 24% of those identified to have GFR in the range of 50–59 mL/min per 1.73 m2 by the MDRD equation had cystatin C levels >1.23 mg/L; their mean cystatin C level was only 1 mg/L (interquartile range, 0.9–1.2 mg/L). This finding was similar for the CG equation. For the Mayo equation, 62.8% of those patients with GFR in the range of 50–59 mL/min per 1.73 m2 had cystatin C levels >1.23 mg/L; their mean cystatin C level was 1.3 mg/L (interquartile range, 1.2–1.5 mg/L). The MDRD and CG equations showed a false-positive rate of >10%. Discussion: We found that the MDRD and CG equations, the current standard to estimate GFR, appeared to overestimate the prevalence of CKD in a general population sample. PMID:20730018

  13. Study on stimulus-responsive cellulose-based polymeric materials

    NASA Astrophysics Data System (ADS)

    Luo, Hongsheng

    Stimulus-responsive cellulose-based polymeric materials were developed by physical and chemical approaches. The thermal, structural, mechanical and morphological properties of the samples were comprehensively investigated by multiple tools. Shape memory effect (SME), programming-structure-property relationship and underling mechanisms were emphasized in this study. Some new concepts, such as heterogeneous-twin-switch, path-dependent multi-shape, rapidly switchable water-sensitive SME were established. The samples were divided into two categories. For the first category, cellulose nano-whiskers (CNWs) were incorporated into crystalline shape memory polyurethane (SMPU) and thermal plastic polyurethane (TPU). The CNW-SMPU nano-composites had heterogeneous switches. Triple- and multi-shape effects were achieved for the CNW-SMPU nano-composites by applying into appropriate thermal-aqueous-mechanical programming. Furthermore, the thermally triggered shape recovery of the composites was found to be tuneable, depending on the PCN content. Theoretical prediction along with numerical analysis was conducted, providing evidence on the possible microstructure of the CNW-SMPU nano-composites. Rapidly switchable water-sensitive SME of the CNW-TPU nano-composites was unprecedentedly studied, which originated from the reversible regulation of hydrogen bonding by water. The samples in the second category consisted of cellulose-polyurethane (PU) blends, cellulose-poly(acrylic acid) (PAA) composites and modified cellulose with supramolecular switches, featuring the requirement of homogeneous cellulose solution in the synthesis process. The reversible behaviours of the cellulose-PU blends in wet-dry cycles as well as the underlying shape memory mechanism were characterized and disclosed. The micro-patterns of the blends were found to be self-similar in fractal dimensions. Cellulose-PAA semi-interpenetrating networks exhibited mechanical adaptability in wet-dry cycles. A type of

  14. Cyberbullying among Finnish adolescents – a population-based study

    PubMed Central

    2012-01-01

    Background Cyberbullying, threatening or harassing another via the internet or mobile phones, does not cause physically harm and thus the consequences are less visible. Little research has been performed on the occurrence of cyberbullying among adolescents or the perception of its seriousness. Only a few population-based studies have been published, none of which included research on the witnessing of cyberbullying. Here, we examined exposure to cyberbullying during the last year, and its frequency and perceived seriousness among 12 to 18-year-old adolescents in Finland. We studied four dimensions of cyberbullying: being a victim, bully, or both victim and bully of cyberbullying, and witnessing the cyberbullying of friends. Methods Self-administered questionnaires, including four questions on cyberbullying, were mailed to a representative sample of 12-, 14-, 16-, and 18-year-old Finns in 2009 (the Adolescent Health and Lifestyle Survey). The respondents could answer via the internet or paper questionnaire. Results The number of respondents was 5516 and the response rate was 56%. Girls more often than boys reported experiencing at least one dimension of cyberbullying during the last year. The proportion was highest among 14-year-olds and lowest among 18-year-olds of both sexes. Among girls, the most commonly encountered dimension was witnessing the cyberbullying of friends (16%); and being a victim was slightly more common than being a bully (11% vs. 9%). Among boys, an equal proportion, approximately 10%, had been a victim, a bully, or had witnessed cyberbullying. The proportion of bully-victims was 4%. Serious and disruptive cyberbullying was experienced by 2% of respondents and weekly cyberbullying by 1%; only 0.5% of respondents had been bullied weekly and considered bullying serious and disruptive. Conclusions Adolescents are commonly exposed to cyberbullying, but it is rarely frequent or considered serious or disruptive. Cyberbullying exposure differed between

  15. Retinal Detachment in Southwest Ethiopia: A Hospital Based Prospective Study

    PubMed Central

    Asaminew, Tsedeke; Gelaw, Yeshigeta; Bekele, Sisay; Solomon, Berhan

    2013-01-01

    Purpose The incidence of retinal detachment in Blacks is generally considered to be low though there are few supporting studies in Africa. This study, thus, aimed at describing the clinical profile of patients with retinal detachment in Southwest Ethiopia. Methods A hospital-based study was done on all consecutive retinal detachment patients who presented to Jimma University Hospital over six months period. A semi-structured questionnaire was used to collect patients’ sociodemographic characteristics and clinical history. Comprehensive anterior and posterior segment eye examinations were done and risk factors were sought for. Statistical tests were considered significant if P < 0.05. Results A total of 94 eyes of 80 patients (1.5%) had retinal detachment (RD) and about 69% of patients were symptomatic for over a month before presentation. The mean age was 41.4 years (SD ±16.5). Fourteen patients (17.5%) had bilateral RD. At presentation, 61 eyes (64.9%) were blind from RD and 11 (13.8%) patients were bilaterally blind from RD. Rhegmatogenous RD was seen in 55 eyes (58.5%) and tractional RD in 22 eyes (23.4%). The most common risk factors were ocular trauma (32 eyes, 34.0%), myopia (23 eyes, 24.5%), posterior uveitis (13 eyes, 13.8%) and diabetic retinopathy (9 eyes, 9.6%). Most retinal breaks (25 eyes, 43.1%) were superotemporal and horse-shoe tear was the most common (19 eyes, 20.2%). Macula was off in 77 eyes (81.9%) and 38 eyes (69.1% of RRD eyes) had grade C proliferative vitreoretinopathy (PVR). Macular status was significantly associated with PVR (P=0.011), and duration of symptoms (RR=1.25, 95%CI: 1.059-1.475, P=0.040). Conclusions A significant numbers of patients with ocular problem had retinal detachment, and nearly two third of the patients presented late. Trauma and myopia were the most important risk factors. People should be educated to improve their health seeking behavior and use eye safety precautions to prevent ocular trauma. PMID:24086614

  16. Cortical Bases of Speech Perception: Evidence from Functional Lesion Studies

    ERIC Educational Resources Information Center

    Boatman, Dana

    2004-01-01

    Functional lesion studies have yielded new information about the cortical organization of speech perception in the human brain. We will review a number of recent findings, focusing on studies of speech perception that use the techniques of electrocortical mapping by cortical stimulation and hemispheric anesthetization by intracarotid amobarbital.…

  17. Studying the Multilingual City: A GIS-Based Approach

    ERIC Educational Resources Information Center

    Veselinova, Ljuba Nikolova; Booza, J. C.

    2009-01-01

    Work in two distinct disciplines, urban geography and sociolinguistics, readily points out the multiethnic and multilingual character of metropolitan areas. However, there is still demand for studies which establish the language structure of modern cities. For the purposes of this pilot study, we focus on the Detroit Metropolitan Area (DMA),…

  18. Videogames, Tools for Change: A Study Based on Activity Theory

    ERIC Educational Resources Information Center

    Méndez, Laura; Lacasa, Pilar

    2015-01-01

    Introduction: The purpose of this study is to provide a framework for analysis from which to interpret the transformations that take place, as perceived by the participants, when commercial video games are used in the classroom. We will show how Activity Theory (AT) is able to explain and interpret these changes. Method: Case studies are…

  19. A Community Based Study of Adult Literacy in North Carolina.

    ERIC Educational Resources Information Center

    Brannon, Yevonne S.; And Others

    A North Carolina study examined the problem of adult illiteracy in Spring 1988. Secondary data for the service areas of eight community colleges chosen as study sites indicated that approximately 25 percent of North Carolinans aged 25 years and older had completed less than the ninth grade in 1980 and the majority of them were unemployed. A review…

  20. Integrating Mathematics and Social Studies: Activities Based on Internet Resources.

    ERIC Educational Resources Information Center

    Abel, Frederick J.; Abel, Jean P.

    "Why are we doing this math stuff, this is social studies class?" This statement reflects the common notion by students that academic disciplines are distinct and separate. While curriculum integration seems to be gaining acceptance again, most integration is done in the traditional manner: math/science or language arts/social studies. The purpose…

  1. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    NASA Technical Reports Server (NTRS)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  2. Probabilistic Study Conducted on Sensor-Based Engine Life Calculation

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei

    2004-01-01

    Turbine engine life management is a very complicated process to ensure the safe operation of an engine subjected to complex usage. The challenge of life management is to find a reasonable compromise between the safe operation and the maximum usage of critical parts to reduce maintenance costs. The commonly used "cycle count" approach does not take the engine operation conditions into account, and it oversimplifies the calculation of the life usage. Because of the shortcomings, many engine components are regularly pulled for maintenance before their usable life is over. And, if an engine has been running regularly under more severe conditions, components might not be taken out of service before they exceed their designed risk of failure. The NASA Glenn Research Center and its industrial and academic partners have been using measurable parameters to improve engine life estimation. This study was based on the Monte Carlo simulation of 5000 typical flights under various operating conditions. First a closed-loop engine model was developed to simulate the engine operation across the mission profile and a thermomechanical fatigue (TMF) damage model was used to calculate the actual damage during takeoff, where the maximum TMF accumulates. Next, a Weibull distribution was used to estimate the implied probability of failure for a given accumulated cycle count. Monte Carlo simulations were then employed to find the profiles of the TMF damage under different operating assumptions including parameter uncertainties. Finally, probabilities of failure for different operating conditions were analyzed to demonstrate the importance of a sensor-based damage calculation in order to better manage the risk of failure and on-wing life.

  3. An insight-based longitudinal study of visual analytics.

    PubMed

    Saraiya, Purvi; North, Chris; Lam, Vy; Duca, Karen A

    2006-01-01

    Visualization tools are typically evaluated in controlled studies that observe the short-term usage of these tools by participants on preselected data sets and benchmark tasks. Though such studies provide useful suggestions, they miss the long-term usage of the tools. A longitudinal study of a bioinformatics data set analysis is reported here. The main focus of this work is to capture the entire analysis process that an analyst goes through from a raw data set to the insights sought from the data. The study provides interesting observations about the use of visual representations and interaction mechanisms provided by the tools, and also about the process of insight generation in general. This deepens our understanding of visual analytics, guides visualization developers in creating more effective visualization tools in terms of user requirements, and guides evaluators in designing future studies that are more representative of insights sought by users from their data sets.

  4. Studies of the activity of catalysts based on heteropolyacids

    NASA Astrophysics Data System (ADS)

    Turek, Wincenty; Lapkowski, Mieczyslaw; Debiec, Joanna; Krowiak, Agnieszka

    2005-10-01

    The catalytic activity of samples such as PPy(H 4SiW 12O 40), PPy(H 5PMo 10V 2O 40), PPy(H 2Fe(III)PMo 10V 2O 40), PPy(H 3Cu(II)PMo 10V 2O 40) has been examined in two different test reactions. The acid-base and oxidation-reduction properties were studied using the conversion of isopropyl alcohol to propene and acetone. Redox ability of catalysts was examined in the reaction of oxidation of allyl alcohol to glycidol. It was found that the activity of catalysts in the oxidation of allyl alcohol increases as the oxidation properties determined from the conversion of isopropyl alcohol increase. It was also observed that stronger oxidation-reduction properties of the catalyst result in a high rate of the consecutive reaction of glycidol to 3-hydroxypropanone. The phase composition of catalysts was determined by means of X-ray diffraction (XRD).

  5. Microbiota-based Signature of Gingivitis Treatments: A Randomized Study

    PubMed Central

    Huang, Shi; Li, Zhen; He, Tao; Bo, Cunpei; Chang, Jinlan; Li, Lin; He, Yanyan; Liu, Jiquan; Charbonneau, Duane; Li, Rui; Xu, Jian

    2016-01-01

    Plaque-induced gingivitis can be alleviated by various treatment regimens. To probe the impacts of various anti-gingivitis treatments on plaque microflora, here a double blinded, randomized controlled trial of 91 adults with moderate gingivitis was designed with two anti-gingivitis regimens: the brush-alone treatment and the brush-plus-rinse treatment. In the later group, more reduction in both Plaque Index (TMQHI) and Gingival Index (mean MGI) at Day 3, Day 11 and Day 27 was evident, and more dramatic changes were found between baseline and other time points for both supragingival plaque microbiota structure and salivary metabonomic profiles. A comparison of plaque microbiota changes was also performed between these two treatments and a third dataset where 50 subjects received regimen of dental scaling. Only Actinobaculum, TM7 and Leptotrichia were consistently reduced by all the three treatments, whereas the different microbial signatures of the three treatments during gingivitis relieve indicate distinct mechanisms of action. Our study suggests that microbiota based signatures can serve as a valuable approach for understanding and potentially comparing the modes of action for clinical treatments and oral-care products in the future. PMID:27094556

  6. Electrochemical studies of calcium chloride-based molten salt systems

    SciTech Connect

    Blanchard, T.P. Jr.

    1992-12-01

    Conductance and EMF studies of CaCl{sub 2}-based melts were performed in the temperature range 790--990 C. Conductivity data collected using magnesia tubes and capillaries showed deviations from the data recommended by the National Bureau of Standards. These deviations are attributed to the slow dissolution of magnesia by the CaCl{sub 2}-CaO melt. Conductivity data for molten CaCl{sub 2} using a pyrolytic boron nitride capillary were in reasonable agreement with the recommended data; however, undissolved CaO in CaCl{sub 2} may have caused blockage of the pyrolytic boron nitride capillary, resulting in fluctuations in the measured resistance. The utility of the AgCl/Ag reference electrode in CaCl{sub 2}-AgCl and CaCl{sub 2}-CaO-AgCl melts, using asbestos diaphragms and Vycor glass as reference half-cell membranes, was also investigated. Nernstian behavior was observed using both types of reference half-cell membranes in CaCl{sub 2}-AgCl melts. The AgCl/Ag reference electrode also exhibited Nernstian behavior in CaCl{sub 2}-CaO-AgCl melts using a Vycor reference half-cell membrane and a magnesia crucible. The use of CaCl{sub 2} as a solvent is of interest since it is used in plutonium metal purification, as well as various other commercial applications. 97 refs., 33 figs., 13 tabs.

  7. Microbiota-based Signature of Gingivitis Treatments: A Randomized Study.

    PubMed

    Huang, Shi; Li, Zhen; He, Tao; Bo, Cunpei; Chang, Jinlan; Li, Lin; He, Yanyan; Liu, Jiquan; Charbonneau, Duane; Li, Rui; Xu, Jian

    2016-01-01

    Plaque-induced gingivitis can be alleviated by various treatment regimens. To probe the impacts of various anti-gingivitis treatments on plaque microflora, here a double blinded, randomized controlled trial of 91 adults with moderate gingivitis was designed with two anti-gingivitis regimens: the brush-alone treatment and the brush-plus-rinse treatment. In the later group, more reduction in both Plaque Index (TMQHI) and Gingival Index (mean MGI) at Day 3, Day 11 and Day 27 was evident, and more dramatic changes were found between baseline and other time points for both supragingival plaque microbiota structure and salivary metabonomic profiles. A comparison of plaque microbiota changes was also performed between these two treatments and a third dataset where 50 subjects received regimen of dental scaling. Only Actinobaculum, TM7 and Leptotrichia were consistently reduced by all the three treatments, whereas the different microbial signatures of the three treatments during gingivitis relieve indicate distinct mechanisms of action. Our study suggests that microbiota based signatures can serve as a valuable approach for understanding and potentially comparing the modes of action for clinical treatments and oral-care products in the future. PMID:27094556

  8. Structural studies of enzyme-based microfluidic biofuel cells

    NASA Astrophysics Data System (ADS)

    Togo, Makoto; Takamura, Akimasa; Asai, Tatsuya; Kaji, Hirokazu; Nishizawa, Matsuhiko

    An enzyme-based glucose/O 2 biofuel cell was constructed within a microfluidic channel to study the influence of electrode configuration and fluidic channel height on cell performance. The cell was composed of a bilirubin oxidase (BOD)-adsorbed O 2 cathode and a glucose anode prepared by co-immobilization of glucose dehydrogenase (GDH), diaphorase (Dp) and VK 3-pendant poly- L-lysine. The consumption of O 2 at the upstream cathode protected the downstream anode from interfering O 2 molecules, and consequently improved the cell performance (maximum cell current) ca. 10% for the present cell. The cell performance was also affected by the channel height. The output current and power of a 0.1 mm-height cell was significantly less than those of a 1 mm-height cell because of the depletion of O 2, as determined by the shape of the E- I curve at the cathode. On the other hand, the volume density of current and power was several times higher for the narrower cell.

  9. Studies of Hydrogen in Ti-Based Quasicrystals

    NASA Astrophysics Data System (ADS)

    Viano, A. M.; Gibbons, P. C.; Kelton, K. F.

    1996-03-01

    The presumed polytetrahedral order and the favorable hydrogen-metal chemistry make Ti-based quasicrystals candidate materials for hydrogen storage applications. The icosahedral phase in tzn453817 has been shown to absorb up to 62 atomic percent of hydrogen with no structural transformation. This is accompanied by a 7% increase in the quasilattice parameter. An oxide layer on the surface of the rapidly quenched quasicrystalline ribbons acts as a barrier to hydrogen absorption by direct gas exposure, and thus alternative loading techniques have been developed and will be discussed. The absorption kinetics and storage capacity are far better for the quasicrystal than for the associated amorphous and crystalline phases in TiZrNi. Two distinct types of fundamental clusters have been propsed for icosahedral phases, the Mackay icoasahedron and the Pauling triacontahedron. Calculations of the distances between tetrahedral interstitial sites in these clusters permits a determination of the maximum number of hydrogen atoms allowed in each cluster. Hydrogen storage ability, then, can be used to determine the cluster type for various icosahedral phase alloys. Hydrogenated quasicrystals constitute a novel metal-hydride system that allows new basic studies and has technological potential for energy applications.

  10. A Photochemically-Based Microphysical Study of Titan Hazes

    NASA Astrophysics Data System (ADS)

    Wilson, E. H.; West, R. A.; Edgington, S. G.; Atreya, S. K.

    2003-05-01

    Titan's haze region acts as an end product of Titan's hydrocarbon and nitrile chemistry and plays an important role in the distribution of atmospheric constituents, affecting the transfer of radiation that helps trigger that chemistry. Recent investigations into the chemical sources of Titan haze [1,2] have suggested that the source region of Titan haze might be lower than what is found in most conventional microphysical models. Furthermore, modeling [1] and laboratory studies [3] have shown that PAHs may be more prominent in Titan haze than previously thought. To analyze the implications of these results we use a microphysical model [4] to calculate a haze distribution of spherical particles based on a photochemical source profile. Results will be compared to observations and the possible consequences of fractal haze particles will be discussed. The effects of haze composition on the distribution of hazes as well as on the radiative transfer and resultant chemistry will be examined and placed in the context of the upcoming Cassini-Huygens mission. This research is supported by the National Research Council Research Associateship Program. [1] E. H. Wilson and S. K. Atreya, Planet. Space Sci., in press. [2] S. Lebonnois et al., Icarus, 159, 505-517, 2002. [3] B. N. Khare et al., Icarus, 160, 172-182, 2002. [4] O. B. Toon et al., J. Atmos. Sci., 45, 2123-2143, 1988.

  11. Satellite-Based Study of Glaciers Retreat in Northern Pakistan

    NASA Astrophysics Data System (ADS)

    Munir, Siraj

    Glaciers serve as a natural regulator of regional water supplies. About 16933 Km 2 area of glaciers is covered by Pakistan. These glaciers are enormous reservoirs of fresh water and their meltwater is an important resource which feed rivers in Pakistan. Glacier depletion, especially recent melting can affect agriculture, drinking water supplies, hydro-electric power, and ecological habitats. This can also have a more immediate impact on Pakistan's economy that depends mainly on water from glacier melt. Melting of seasonal snowfall and permanent glaciers has resulted not only in reduction of water resources but also caused flash floods in many areas of Pakistan. With the advent of satellite technology, using optical and SAR data the study of glaciers, has become possible. Using temporal data, based on calculation of snow index, band ratios and texture reflectance it has been revealed that the rate of glacier melting has increased as a consequent of global warming. Comparison of Landsat images of Batura glacier for October 1992 and October 2000 has revealed that there is a decrease of about 17 sq km in Batura glaciers. Although accurate changes in glacier extent cannot be assessed without baseline information, these efforts have been made to analyze future changes in glaciated area.

  12. Quantitative study of osteoporosis model based on synchrotron radiation.

    PubMed

    Xu, Wangyang; Xu, Jun; Zhao, Jun; Sun, Jianqi

    2015-01-01

    To investigate the changes of different periods of primary osteoporosis, we made quantitative analysis of osteoporosis using synchrotron radiation computed tomography (SRCT), together with histomorphometry analysis and finite element analysis (FEA). Tibias, femurs and lumbar vertebras were dissected from sham-ovariectomy rats and ovariectomized rats suffering from osteoporosis at certain time points. The samples were scanned by SRCT and then FEA was applied based on reconstructed slices. Histomorphometry analysis showed that the structure of some trabecular in osteoporosis degraded as the bone volume decreased, for femurs, the bone volume fraction (BV/TV) decreased from 69% to 43%. That led to the increase of the thickness of trabecular separation (from 45.05μm to 97.09μm) and the reduction of the number of trabecular (from 7.99 mm(-1) to 5.97mm(-1)). Simulation of various mechanical tests indicated that, with the exacerbation of osteoporosis, the bones' ability of resistance to compression, bending and torsion gradually became weaker. The compression stiffness decreased from 1770.96 Fμm(-1) to 697.41 Fμm(-1), and it matched the histomorphometry analysis. This study suggested that the combination of both analysis could quantitatively analyze the bone strength in good accuracy. PMID:26737752

  13. Rehabilitation regimes based upon psychophysical studies of prosthetic vision

    NASA Astrophysics Data System (ADS)

    Chen, S. C.; Suaning, G. J.; Morley, J. W.; Lovell, N. H.

    2009-06-01

    Human trials of prototype visual prostheses have successfully elicited visual percepts (phosphenes) in the visual field of implant recipients blinded through retinitis pigmentosa and age-related macular degeneration. Researchers are progressing rapidly towards a device that utilizes individual phosphenes as the elementary building blocks to compose a visual scene. This form of prosthetic vision is expected, in the near term, to have low resolution, large inter-phosphene gaps, distorted spatial distribution of phosphenes, restricted field of view, an eccentrically located phosphene field and limited number of expressible luminance levels. In order to fully realize the potential of these devices, there needs to be a training and rehabilitation program which aims to assist the prosthesis recipients to understand what they are seeing, and also to adapt their viewing habits to optimize the performance of the device. Based on the literature of psychophysical studies in simulated and real prosthetic vision, this paper proposes a comprehensive, theoretical training regime for a prosthesis recipient: visual search, visual acuity, reading, face/object recognition, hand-eye coordination and navigation. The aim of these tasks is to train the recipients to conduct visual scanning, eccentric viewing and reading, discerning low-contrast visual information, and coordinating bodily actions for visual-guided tasks under prosthetic vision. These skills have been identified as playing an important role in making prosthetic vision functional for the daily activities of their recipients.

  14. Performance Study of optical Modulator based on electrooptic effect

    NASA Astrophysics Data System (ADS)

    Palodiya, V.; Raghuwanshi, S. K.

    2016-08-01

    In this paper, we have studied and derive performance parameter of highly integrated Lithium Niobate optical modulator. This is a chirp free modulator having low switching voltage and large bandwidth. For an external modulator in which travelling-wave electrodes length L imposed the modulating switching voltage, the product of Vπ and L is fixed for a given electro optic material Lithium Niobate. We investigate to achieve a low Vπ by both magnitude of the electro-optic coefficient for a wide variety of electro-optic materials. A Sellmeier equation for the extraordinary index of congruent lithium niobate is derived. For phase-matching, predictions are accmate for temperature between room temperature 250°C and wavelength ranging from 0.4 to 5µm. The Sellmeier equations predict more accmately refractive indices at long wavelengths. Theoretical result is confirmed by simulated results. We have analysed the various parameters such as switching voltage, device performance index, time constant, transmittance, cut-off frequency, 3-dB bandwidth, power absorption coefficient and transmission bit rate of Lithium Niobate optical Modulator based on electro -optic effect.

  15. Study of emotion-based neurocardiology through wearable systems

    NASA Astrophysics Data System (ADS)

    Ramasamy, Mouli; Varadan, Vijay

    2016-04-01

    Neurocardiology is the exploration of neurophysiological, neurological and neuroanatomical facets of neuroscience's influence in cardiology. The paraphernalia of emotions on the heart and brain are premeditated because of the interaction between the central and peripheral nervous system. This is an investigative attempt to study emotion based neurocardiology and the factors that influence this phenomena. The factors include: interaction between sleep EEG (electroencephalogram) and ECG (electrocardiogram), relationship between emotion and music, psychophysiological coherence between the heart and brain, emotion recognition techniques, and biofeedback mechanisms. Emotions contribute vitally to the mundane life and are quintessential to a numerous biological and everyday-functional modalities of a human being. Emotions are best represented through EEG signals, and to a certain extent, can be observed through ECG and body temperature. Confluence of medical and engineering science has enabled the monitoring and discrimination of emotions influenced by happiness, anxiety, distress, excitement and several other factors that influence the thinking patterns and the electrical activity of the brain. Similarly, HRV (Heart Rate Variability) widely investigated for its provision and discerning characteristics towards EEG and the perception in neurocardiology.

  16. Neutrino-nucleus reactions based on recent structure studies

    SciTech Connect

    Suzuki, Toshio

    2015-05-15

    Neutrino-nucleus reactions are studied with the use of new shell model Hamiltonians, which have proper tensor components in the interactions and prove to be successful in the description of Gamow-Teller (GT) strengths in nuclei. The new Hamiltonians are applied to obtain new neutrino-nucleus reaction cross sections in {sup 12}C, {sup 13}C, {sup 56}Fe and {sup 56}Ni induced by solar and supernova neutrinos. The element synthesis by neutrino processes in supernova explosions is discussed with the new cross sections. The enhancement of the production yields of {sup 7}Li, {sup 11}B and {sup 55}Mn is obtained while fragmented GT strength in {sup 56}Ni with two-peak structure is found to result in smaller e-capture rates at stellar environments. The monopole-based universal interaction with tensor force of π+ρ meson exchanges is used to evaluate GT strength in {sup 40}Ar and ν-induced reactions on {sup 40}Ar. It is found to reproduce well the experimental GT strength in {sup 40}Ar.

  17. Exploring Global Change In Place-Based Case Studies

    NASA Astrophysics Data System (ADS)

    Moosavi, S. C.

    2011-12-01

    The complexity of global climate change makes the subject challenging for the average student, particularly given the nuanced feedbacks and exceptions to the general "warming" or "drying" trend that may be experienced at the local and regional level at which most people experience geologic processes. Geoscience educators can reduce these barriers and draw in student learners by adopting a place-based approach to teaching and researching geologic principles that relate to global change. Assisting students in recognizing and understanding the geologic environment in which they live and study has the side benefit of making the potential effect of climate change tangible. This presentation will review several approaches for using place-based case studies to explore global climate change issues in large lecture, small seminar, field research and service learning environments. The special place project used in large introductory physical geology courses requires each student to select a place familiar and unique to them for an in depth study of the common course content as the semester progresses. Students are specifically tasked with identifying how their site came to be, the geologic processes that act upon it today, how the site may have been different during the last glacial advance and how global climate change (specifically warming of 3OC over 50 years) might impact the site. The concept that change has occurred at the student's site in the past, even far from glacial environments, opens students to the scale of potential anthropogenic climate change. A freshman seminar Global Warming & Climate Change - Service in Preparation for Climate Change: The Second Battle of New Orleans focused on the environmental threats to New Orleans and southeastern Louisiana resulting from regional land use decisions in the centuries before Hurricane Katrina, and the threat that global change relating to sea level rise, acceleration of the hydrologic cycle and intensification of

  18. Method ruggedness studies incorporating a risk based approach: a tutorial.

    PubMed

    Borman, Phil J; Chatfield, Marion J; Damjanov, Ivana; Jackson, Patrick

    2011-10-10

    This tutorial explains how well thought-out application of design and analysis methodology, combined with risk assessment, leads to improved assessment of method ruggedness. The authors define analytical method ruggedness as an experimental evaluation of noise factors such as analyst, instrument or stationary phase batch. Ruggedness testing is usually performed upon transfer of a method to another laboratory, however, it can also be employed during method development when an assessment of the method's inherent variability is required. The use of a ruggedness study provides a more rigorous method for assessing method precision than a simple comparative intermediate precision study which is typically performed as part of method validation. Prior to designing a ruggedness study, factors that are likely to have a significant effect on the performance of the method should be identified (via a risk assessment) and controlled where appropriate. Noise factors that are not controlled are considered for inclusion in the study. The purpose of the study should be to challenge the method and identify whether any noise factors significantly affect the method's precision. The results from the study are firstly used to identify any special cause variability due to specific attributable circumstances. Secondly, common cause variability is apportioned to determine which factors are responsible for most of the variability. The total common cause variability can then be used to assess whether the method's precision requirements are achievable. The approach used to design and analyse method ruggedness studies will be covered in this tutorial using a real example.

  19. Agent-Based vs. Equation-based Epidemiological Models:A Model Selection Case Study

    SciTech Connect

    Sukumar, Sreenivas R; Nutaro, James J

    2012-01-01

    This paper is motivated by the need to design model validation strategies for epidemiological disease-spread models. We consider both agent-based and equation-based models of pandemic disease spread and study the nuances and complexities one has to consider from the perspective of model validation. For this purpose, we instantiate an equation based model and an agent based model of the 1918 Spanish flu and we leverage data published in the literature for our case- study. We present our observations from the perspective of each implementation and discuss the application of model-selection criteria to compare the risk in choosing one modeling paradigm to another. We conclude with a discussion of our experience and document future ideas for a model validation framework.

  20. Integrated Genome-Based Studies of Shewanella Ecophysiology

    SciTech Connect

    Zhou, Jizhong; He, Zhili

    2014-04-08

    As a part of the Shewanella Federation project, we have used integrated genomic, proteomic and computational technologies to study various aspects of energy metabolism of two Shewanella strains from a systems-level perspective.

  1. COMSOL-based Nuclear Reactor Kinetics Studies at the HFIR

    SciTech Connect

    Chandler, David; Freels, James D; Maldonado, G Ivan; Primm, Trent

    2011-01-01

    The computational ability to accurately predict the dynamic behavior of a nuclear reactor core in response to reactivity-induced perturbations is an important subject in reactor physics. Space-time and point kinetics methodologies were developed for the purpose of studying the transient-induced behavior of the High Flux Isotope Reactor s (HFIR) compact core. The space-time simulations employed the three-energy-group neutron diffusion equations, and transients initiated by control cylinder and hydraulic tube rabbit ejections were studied. The work presented here is the first step towards creating a comprehensive multiphysics methodology for studying the dynamic behavior of the HFIR core during reactivity perturbations. The results of these studies show that point kinetics is adequate for small perturbations in which the power distribution is assumed to be time-independent, but space-time methods must be utilized to determine localized effects.

  2. Hooking the Geographer in Children with Field-Based Studies

    ERIC Educational Resources Information Center

    Krall, Florence; And Others

    1978-01-01

    Suggests projects to help elementary students learn about man-land relationships through field experience, inquiry techniques, and a thematic, interdisciplinary approach. Children study a natural community, a human community, solid wastes, and energy conservation. (Author/AV)

  3. Aeroelastic Optimization Study Based on X-56A Model

    NASA Technical Reports Server (NTRS)

    Li, Wesley; Pak, Chan-Gi

    2014-01-01

    A design process which incorporates the object-oriented multidisciplinary design, analysis, and optimization (MDAO) tool and the aeroelastic effects of high fidelity finite element models to characterize the design space was successfully developed and established. Two multidisciplinary design optimization studies using an object-oriented MDAO tool developed at NASA Armstrong Flight Research Center were presented. The first study demonstrates the use of aeroelastic tailoring concepts to minimize the structural weight while meeting the design requirements including strength, buckling, and flutter. A hybrid and discretization optimization approach was implemented to improve accuracy and computational efficiency of a global optimization algorithm. The second study presents a flutter mass balancing optimization study. The results provide guidance to modify the fabricated flexible wing design and move the design flutter speeds back into the flight envelope so that the original objective of X-56A flight test can be accomplished.

  4. Familial risk of cerebral palsy: population based cohort study

    PubMed Central

    Wilcox, Allen J; Lie, Rolv T; Moster, Dag

    2014-01-01

    Objective To investigate risks of recurrence of cerebral palsy in family members with various degrees of relatedness to elucidate patterns of hereditability. Design Population based cohort study. Setting Data from the Medical Birth Registry of Norway, linked to the Norwegian social insurance scheme to identify cases of cerebral palsy and to databases of Statistics Norway to identify relatives. Participants 2 036 741 Norwegians born during 1967-2002, 3649 of whom had a diagnosis of cerebral palsy; 22 558 pairs of twins, 1 851 144 pairs of first degree relatives, 1 699 856 pairs of second degree relatives, and 5 165 968 pairs of third degree relatives were identified. Main outcome measure Cerebral palsy. Results If one twin had cerebral palsy, the relative risk of recurrence of cerebral palsy was 15.6 (95% confidence interval 9.8 to 25) in the other twin. In families with an affected singleton child, risk was increased 9.2 (6.4 to 13)-fold in a subsequent full sibling and 3.0 (1.1 to 8.6)-fold in a half sibling. Affected parents were also at increased risk of having an affected child (6.5 (1.6 to 26)-fold). No evidence was found of differential transmission through mothers or fathers, although the study had limited power to detect such differences. For people with an affected first cousin, only weak evidence existed for an increased risk (1.5 (0.9 to 2.7)-fold). Risks in siblings or cousins were independent of sex of the index case. After exclusion of preterm births (an important risk factor for cerebral palsy), familial risks remained and were often stronger. Conclusions People born into families in which someone already has cerebral palsy are themselves at elevated risk, depending on their degree of relatedness. Elevated risk may extend even to third degree relatives (first cousins). The patterns of risk suggest multifactorial inheritance, in which multiple genes interact with each other and with environmental factors. These data offer additional

  5. Mortality in Autism: A Prospective Longitudinal Community-Based Study

    ERIC Educational Resources Information Center

    Gillberg, Christopher; Billstedt, Eva; Sundh, Valter; Gillberg, I. Carina

    2010-01-01

    The purposes of the present study were to establish the mortality rate in a representative group of individuals (n = 120) born in the years 1962-1984, diagnosed with autism/atypical autism in childhood and followed up at young adult age (greater than or equal to 18 years of age), and examine the risk factors and causes of death. The study group,…

  6. Solderability Study of RABiTS-Based YBCO Coated Conductors

    SciTech Connect

    Zhang, Yifei; Duckworth, Robert C; Ha, Tam T; Gouge, Michael J

    2011-01-01

    The solderability of commercially available YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) coated conductors that were made from Rolling Assisted Biaxially Textured Substrates (RABiTS)-based templates was studied. The coated conductors, also known as second-generation (2G) high temperature superconductor (HTS) wires (in the geometry of flat tapes about 4 mm wide), were laminated with copper, brass, or stainless steel strips as stabilizers. To understand the factors that influence their solderability, surface profilometry and scanning electron microscopy were used to characterize the wire surfaces. The solderability of three solders, 52In48Sn, 67Bi33In, and 100In (wt.%), was evaluated using a standard test (IPC/ECA J-STD-002) and with two different commercial fluxes. It was found that the solderability varied with the solder and flux but the three different wires showed similar solderability for a fixed combination of solder and flux. Solder joints of the 2G wires were fabricated using the tools and the procedures recommended by the HTS wire manufacturer. The solder joints were made in a lap-joint geometry and with the superconducting sides of the two wires face-to-face. The electrical resistances of the solder joints were measured at 77 K, and the results were analyzed to qualify the soldering materials and evaluate the soldering process. It was concluded that although the selection of soldering materials affected the resistance of a solder joint, the resistivity of the stabilizer was the dominant factor.

  7. Parametric Study Conducted of Rocket- Based, Combined-Cycle Nozzles

    NASA Technical Reports Server (NTRS)

    Steffen, Christopher J., Jr.; Smith, Timothy D.

    1998-01-01

    Having reached the end of the 20th century, our society is quite familiar with the many benefits of recycling and reusing the products of civilization. The high-technology world of aerospace vehicle design is no exception. Because of the many potential economic benefits of reusable launch vehicles, NASA is aggressively pursuing this technology on several fronts. One of the most promising technologies receiving renewed attention is Rocket-Based, Combined-Cycle (RBCC) propulsion. This propulsion method combines many of the efficiencies of high-performance jet aircraft with the power and high-altitude capability of rocket engines. The goal of the present work at the NASA Lewis Research Center is to further understand the complex fluid physics within RBCC engines that govern system performance. This work is being performed in support of NASA's Advanced Reusable Technologies program. A robust RBCC engine design optimization demands further investigation of the subsystem performance of the engine's complex propulsion cycles. The RBCC propulsion system under consideration at Lewis is defined by four modes of operation in a singlestage- to-orbit configuration. In the first mode, the engine functions as a rocket-driven ejector. When the rocket engine is switched off, subsonic combustion (mode 2) is present in the ramjet mode. As the vehicle continues to accelerate, supersonic combustion (mode 3) occurs in the ramjet mode. Finally, as the edge of the atmosphere is approached and the engine inlet is closed off, the rocket is reignited and the final accent to orbit is undertaken in an all-rocket mode (mode 4). The performance of this fourth and final mode is the subject of this present study. Performance is being monitored in terms of the amount of thrust generated from a given amount of propellant.

  8. Increasing incidence of cataract surgery: Population-based study

    PubMed Central

    Gollogly, Heidrun E.; Hodge, David O.; St. Sauver, Jennifer L.; Erie, Jay C.

    2015-01-01

    PURPOSE To estimate the incidence of cataract surgery in a defined population and to determine longitudinal cataract surgery patterns. SETTING Mayo Clinic, Rochester, Minnesota, USA. DESIGN Cohort study. METHODS Rochester Epidemiology Project (REP) databases were used to identify all incident cataract surgeries in Olmsted County, Minnesota, between January 1, 2005, and December 31, 2011. Age-specific and sex-specific incidence rates were calculated and adjusted to the 2010 United States white population. Data were merged with previous REP data (1980 to 2004) to assess temporal trends in cataract surgery. Change in the incidence over time was assessed by fitting generalized linear models assuming a Poisson error structure. The probability of second-eye cataract surgery was calculated using the Kaplan-Meier method. RESULTS Included were 8012 cataract surgeries from 2005 through 2011. During this time, incident cataract surgery significantly increased (P < .001), peaking in 2011 with a rate of 1100 per 100 000 (95% confidence interval, 1050–1160). The probability of second-eye surgery 3, 12, and 24 months after first-eye surgery was 60%, 76%, and 86%, respectively, a significant increase compared with the same intervals in the previous 7 years (1998 to 2004) (P < .001). When merged with 1980 to 2004 REP data, incident cataract surgery steadily increased over the past 3 decades (P < .001). CONCLUSION Incident cataract surgery steadily increased over the past 32 years and has not leveled off, as reported in Swedish population-based series. Second-eye surgery was performed sooner and more frequently, with 60% of residents having second-eye surgery within 3-months of first-eye surgery. PMID:23820302

  9. Recurrent Wheezing in Infants: A Population-Based Study.

    PubMed

    Belhassen, Manon; De Blic, Jacques; Laforest, Laurent; Laigle, Valérie; Chanut-Vogel, Céline; Lamezec, Liliane; Brouard, Jacques; Fauroux, Brigitte; de Pouvourville, Gérard; Ginoux, Marine; Van Ganse, Eric

    2016-04-01

    Recurrent wheezing (RW) has a significant impact on infants, caregivers, and society, but morbidity and related medical resource utilization (MRU) have not been thoroughly explored. The burden of RW needs to be documented with population-based data. The objective was to assess the characteristics, medical management, and MRU of RW infants identified from national claims data. Infants aged from 6 to 24 months, receiving ≥2 dispensations of respiratory drugs within 3 months, and presenting a marker of poor control (index date), were selected. During the 6 months after index date, MRU was described in the cohort and among 3 subgroups with more severe RW, defined as ≥4 dispensations of respiratory drugs, ≥3 dispensations of oral corticosteroids (OCS), or ≥1 hospitalization for respiratory symptoms. A total of 115,489 infants had RW, corresponding to 8.2% of subjects in this age group. During follow-up, 68.7% of infants received inhaled corticosteroids, but only 1.8 U (unit) were dispensed over 6 months, suggesting discontinuous use. Control was mostly inadequate: 61.7% of subjects received OCS, 80.2% antibiotics, and 71.2% short-acting beta-agonists, and medical/paramedical visits were numerous, particularly for physiotherapy. Severe RW concerned 39.0% of the cohort; 32.8% and 11.7% of infants had repeated use of respiratory drugs and OCS, respectively, and 5.5% were hospitalized for respiratory symptoms. In this real-life nation-wide study, RW was common and infants had poor control and high MRU. Interventions are needed to support adequate use of controller therapy, and to improve medical care. PMID:27082618

  10. Undernutrition among Indian men: a study based on NFHS-3.

    PubMed

    Patil, Yashwant Pandharinath; Shinde, Ramkrishna Lahu

    2014-11-01

    The objective of this study was to evaluate zonal and state-wise prevalence and risk factors of undernutrition among Indian men in the age-group of 15 to 54 years based on sampled data of 74,369 respondents from the National Family Health Survey-3. A common anthropometric measure, body mass index, is used to determine the prevalence as it is considered to be a good measure of undernutrition. Overall, 28.6% (SE=0.17%) of Indian men are classified as underweight, and 52.5% (SE=0.62%) of the younger age-group (15-19 years) are underweight. The highest prevalence of underweight men in Indian states is observed in Tripura (39.8%; SE=1.85%), followed by Rajasthan (39.3%; SE=1.28%), Chhattisgarh (37.2%; SE=1.3%), and Gujarat (35.7%; SE=1.3%). The highest and lowest prevalence among zones are reported for central (34.5%; SE=0.39%) and northeast (18%; SE=0.34%) zones, respectively. The bivariate analysis using chi-square test concludes the significant association (p<.001) between the body mass index groups and each of the explanatory variable. Significant difference (p≤.002) is reported in the mean heights of underweight and non-underweight men among four out of six zones of India. From multivariate logistic regression analysis, we observed that for India as a whole, men with no education, low/medium standard of living, and the younger age-group (15-19 years) have significantly (p<.001) higher chances of being underweight. We also observed similar results for many Indian states at different significance levels. In conclusion, the distribution of underweight in India remains segregated by socioeconomic status.

  11. [Mechanical studies on casting titanium alloy denture base].

    PubMed

    Ito, M

    1990-03-01

    The mechanical properties of the Akers type clasp, bar and frame made by the newly developed Ti-20Cr-0.2Si alloy were studied in order to obtain the indices for designing the cast partial denture base. In the case of the clasp, the bending strength of the Ti-20Cr-0.2Si alloy and pure Ti was lower than that of the Co-Cr alloy. The Ti-20Cr-0.2Si alloy and pure Ti may have the same retentive force as the gold type IV alloy because its bending behavior was similar to that of the gold alloy. In the cyclic bending test, the permanent deflection of the Ti-20Cr-0.2Si alloy was lower than that of the pure Ti and Co-Cr alloy. It had almost the same value as that of the gold alloy. Considering the permanent deflection and fracture, it is preferable that the undercut of the abutment tooth for the Ti-20Cr-0.02Si alloy clasp is 0.50mm or less. The Ti-20Cr-0.2Si alloy bars and frame showed the same bending behavior and strain distribution as the gold alloy. In the case of the Ti-20Cr-0.2Si alloy bar thickened about 30%, the strain was decreased and close to that of the Co-Cr alloy. It was suggested that the Ti-20Cr-0.2Si alloy bar or frame should be designed like the gold alloy. PMID:2196313

  12. Studies of Electronic Conduction in Some Small Gallium Arsenic Based.

    NASA Astrophysics Data System (ADS)

    Whittington, Geoffrey

    Available from UMI in association with The British Library. Requires signed TDF. This thesis describes experimental investigations of the physics involved with low temperature electronic conduction in three different semiconductor systems. The research relies upon technological advances in fabrication of such semiconductor samples. The first work deals with the effects of quantum interference of electrons in some submicron size, heavily doped Gallium Arsenide wire samples. The interesting effect of aperiodic fluctuations in the magnetoresistance of these samples is studied, making use of recently formulated theory on the subject, and with experimental data taken over the magnetic field range 0 to 10 tesla. The results verify the connection between the mean amplitude of the fluctuations and the field correlation period, in terms of the correlation function introduced in the theory. The second work is on the impurity-assisted tunnelling conduction in a magnetic field of three thin rm n^{+}/n^{-}/n^ {+} GaAs sandwich layer structures. The conduction of the system is shown to be determined by impurities lying in the centre of the middle layer. This allows the connection to be made between the conductivity of the system in a magnetic field, and the field-dependent shape of the donor electron wavefunction. The relative variation in resistance with angle to an applied magnetic field was measured, and is shown to be in agreement with predictions based on calculations of the shape of a normalised hydrogenic state wavefunction in high magnetic fields. The third work concerns the tunnelling conduction of a symmetrical GaAs/(AlGa)As/GaAs hetero-barrier system. The current-voltage characteristics at low temperature are fully modelled for applied voltages up to 180mV, using conventional theory of tunnelling and a position-dependent effective mass in the barrier. Low current oscillations in the Fowler-Nordheim tunnelling regime, corresponding to quantum reflection at the

  13. A School-Based Study on Situational Interest of Investigative Study in Senior Physics

    ERIC Educational Resources Information Center

    Leung, Yat-yin

    2015-01-01

    This paper reports the findings from the interview data of a research aiming at studying how to trigger students' situational interest in physics and its implications on learning and teaching in the New Senior Secondary (NSS) physics curriculum. 49 students from a boys' school were invited to write one to three learning experiences in physics that…

  14. Aeroelastic Optimization Study Based on the X-56A Model

    NASA Technical Reports Server (NTRS)

    Li, Wesley W.; Pak, Chan-Gi

    2014-01-01

    One way to increase the aircraft fuel efficiency is to reduce structural weight while maintaining adequate structural airworthiness, both statically and aeroelastically. A design process which incorporates the object-oriented multidisciplinary design, analysis, and optimization (MDAO) tool and the aeroelastic effects of high fidelity finite element models to characterize the design space was successfully developed and established. This paper presents two multidisciplinary design optimization studies using an object-oriented MDAO tool developed at NASA Armstrong Flight Research Center. The first study demonstrates the use of aeroelastic tailoring concepts to minimize the structural weight while meeting the design requirements including strength, buckling, and flutter. Such an approach exploits the anisotropic capabilities of the fiber composite materials chosen for this analytical exercise with ply stacking sequence. A hybrid and discretization optimization approach improves accuracy and computational efficiency of a global optimization algorithm. The second study presents a flutter mass balancing optimization study for the fabricated flexible wing of the X-56A model since a desired flutter speed band is required for the active flutter suppression demonstration during flight testing. The results of the second study provide guidance to modify the wing design and move the design flutter speeds back into the flight envelope so that the original objective of X-56A flight test can be accomplished successfully. The second case also demonstrates that the object-oriented MDAO tool can handle multiple analytical configurations in a single optimization run.

  15. A study on the cytotoxicity of carbon-based materials.

    PubMed

    Saha, Dipendu; Heldt, Caryn L; Gencoglu, Maria F; Vijayaragavan, K Saagar; Chen, Jihua; Saksule, Ashish

    2016-11-01

    With an aim to understand the origin and key contributing factors towards carbon-induced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, X-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROS) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicity in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under this study. None of the carbons induced oxidative stress to the cells as indicated by the ROS generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell.

  16. Low temperature rheological studies of hydrocarbon base lubricants

    SciTech Connect

    Venerus, D.C.; Klaus, E.E.; Duda, J.L.

    1987-01-01

    This study is designed to evaluate the rheological properties of samples of waxy mineral oil, a wax-free hydrocarbon solvent, wax-free polymer-thickened oils and fully formulated lubricants containing wax and polymer in hydrocarbon solvents. A mechanical spectrometer (cone and plate rotational viscometer) and the mini rotary viscometer were used in these studies. The cooling rate and cold soak times were computer programmed using a mechanical system. A compromise system using a cooling rate of 0.56/sup 0/C/min and a cold soak time of one hour was used in order to produce data in a reasonable time. These values were chosen from the information gained on wax crystal growth and equilibration from the low temperature dewaxing studies conducted at this laboratory.

  17. Data book: Space station/base food system study. Book 3: Study selection rationale sheets

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The supporting rationale sheets are presented which were utilized in the selection and support of the concepts considered in the final phase of the study. Each concept, conceived to fulfill a specific function of the food system, was assessed in terms of the eight critical factors depicted on the rationale sheet. When weighted and totaled, the resulting selection factor was used as a guide in making the final decision.

  18. Studies of zeolite-based artificial photosynthetic systems

    NASA Astrophysics Data System (ADS)

    Zhang, Haoyu

    Y were obtained. The Ru complexes were anchored on the surface of zeolites via ion-exchange or "ship-in-bottle" synthesis. The spectroscopic properties of the NanoY-entrapped species including methyl viologen (MV2+), RuL were measured via transmission techniques. The zeolite-encapsulated species were found to have red-shift absorption and emission bands and longer MLCT life times. By incorporating both donors Ru complexes and acceptors MV2+ in NanoY, electron transfer kinetics was examined. LFP study showed a slower back-electron-transfer rate as compared to forward electron transfer. Photochemically generated long-lived charge separation is the key step in processes that aim for conversion of solar energy into chemical energy. We incorporated RuL complex on the surface of a pinhole-free zeolite membrane by quaternization of L and surrounded with intrazeolitic bipyridinium ions (N,N'-trimethyl-2,2'-bipyridinium ion, 3DQ2+). Visible-light irradiation of the Ru complex side of the membrane in the presence of a sacrificial electron donor led to formation of PVS-· on the other side. Pore-blocking disilazane-based chemistry allows for Na+ to migrate through the membrane to maintain charge balance, while keeping the 3DQ2+ entrapped in the zeolite. These results provided encouragement that the zeolite membrane based architecture has the necessary features for not only incorporating molecular assemblies with long-lived charge separation but also for ready exploitation of the spatially separated charges to store visible light energy in chemical species. The pore-narrowing strategy applied under mild conditions can be used in control-release of active substances such as drug, pesticides, and herbicides. Methyl viologen (MV2+) was chosen as the guest molecule, since it is widely used as an herbicide and its release is of interest in agricultural applications. To explore the controlled-release capability of the surface-modified zeolite, MV2+-encapsulated zeolite Y particles were

  19. Postmarketing Safety Study Tool: A Web Based, Dynamic, and Interoperable System for Postmarketing Drug Surveillance Studies.

    PubMed

    Sinaci, A Anil; Laleci Erturkmen, Gokce B; Gonul, Suat; Yuksel, Mustafa; Invernizzi, Paolo; Thakrar, Bharat; Pacaci, Anil; Cinar, H Alper; Cicekli, Nihan Kesim

    2015-01-01

    Postmarketing drug surveillance is a crucial aspect of the clinical research activities in pharmacovigilance and pharmacoepidemiology. Successful utilization of available Electronic Health Record (EHR) data can complement and strengthen postmarketing safety studies. In terms of the secondary use of EHRs, access and analysis of patient data across different domains are a critical factor; we address this data interoperability problem between EHR systems and clinical research systems in this paper. We demonstrate that this problem can be solved in an upper level with the use of common data elements in a standardized fashion so that clinical researchers can work with different EHR systems independently of the underlying information model. Postmarketing Safety Study Tool lets the clinical researchers extract data from different EHR systems by designing data collection set schemas through common data elements. The tool interacts with a semantic metadata registry through IHE data element exchange profile. Postmarketing Safety Study Tool and its supporting components have been implemented and deployed on the central data warehouse of the Lombardy region, Italy, which contains anonymized records of about 16 million patients with over 10-year longitudinal data on average. Clinical researchers in Roche validate the tool with real life use cases. PMID:26543873

  20. Postmarketing Safety Study Tool: A Web Based, Dynamic, and Interoperable System for Postmarketing Drug Surveillance Studies

    PubMed Central

    Sinaci, A. Anil; Laleci Erturkmen, Gokce B.; Gonul, Suat; Yuksel, Mustafa; Invernizzi, Paolo; Thakrar, Bharat; Pacaci, Anil; Cinar, H. Alper; Cicekli, Nihan Kesim

    2015-01-01

    Postmarketing drug surveillance is a crucial aspect of the clinical research activities in pharmacovigilance and pharmacoepidemiology. Successful utilization of available Electronic Health Record (EHR) data can complement and strengthen postmarketing safety studies. In terms of the secondary use of EHRs, access and analysis of patient data across different domains are a critical factor; we address this data interoperability problem between EHR systems and clinical research systems in this paper. We demonstrate that this problem can be solved in an upper level with the use of common data elements in a standardized fashion so that clinical researchers can work with different EHR systems independently of the underlying information model. Postmarketing Safety Study Tool lets the clinical researchers extract data from different EHR systems by designing data collection set schemas through common data elements. The tool interacts with a semantic metadata registry through IHE data element exchange profile. Postmarketing Safety Study Tool and its supporting components have been implemented and deployed on the central data warehouse of the Lombardy region, Italy, which contains anonymized records of about 16 million patients with over 10-year longitudinal data on average. Clinical researchers in Roche validate the tool with real life use cases. PMID:26543873

  1. Thermoelectric study of INSB secondary phase based nano composite materials

    NASA Astrophysics Data System (ADS)

    Zhu, Song

    In the past several decades there has been an intensive study in the field of thermoelectric study that is basically materials driven. As the simplest technology applicable in direct heat-electricity energy conversion, thermoelectricity utilizes the Seebeck effect to generate electricity from heat or conversely achieve the solid-state cooling via the Peltier effect. With many technical merits, thermoelectric devices can be used as spot-size generators or distributed refrigerators, however, their applications are restricted by the energy conversion efficiency, which is mainly determined by the figure of merit ZT of the thermoelectric materials that these devices are made of. A higher ZT (ZT=alpha2*sigma/kappa) entails a larger Seebeck coefficient (alpha), a higher electrical conductivity (sigma) and a lower thermal conductivity (kappa). However, it is challenging to simultaneously optimize these three material parameters because they are adversely correlated. To this end, a promising approach to answer this challenge is nano-compositing or microstructuring at multiple length scales. The numerous grain boundaries in nano-composite allow for significant reduction of lattice thermal conductivity via strong phonon scattering and as well an enhanced Seebeck coefficient via, carrier energy filtering effect. As the same grain boundaries also scatter carriers, a coherent interface between grains is needed to minimize the degradation of carrier mobilities. To this end,in-situ, instead of ex-situ, formation of nano-composite is preferred. It is noteworthy that electrical conductivity can be further enhanced by the injection of high-mobility carriers introduced by the secondary nano-phase. In view of the prevalent use of Antimony (Sb) in thermoelectric materials, Indium Antimonide (InSb) naturally becomes one of the most promising nano-inclusions since it possesses one of the largest carrier mobilities (˜7.8 m 2/V-s) in any semiconductors, while at the same time possesses a

  2. INTEGRATED GENOME-BASED STUDIES OF SHEWANELLA ECOPHYSIOLOGY

    SciTech Connect

    NEALSON, KENNETH H.

    2013-10-15

    laboratories. Applications: 1. Corrosion: Electron flow is often part of the corrosive process, and several studies were done in concert with this proposal with regard to the ability of EET-capable bacteria to enhance, inhibit, or detect corrosion. These included using EET-capable bacteria to detect corrosion in its earliest stages [5], to use corrosion-causing bacteria for the study of the microbe/mineral interface during corrosion [1], and to study the groups of microbes involved with corrosion of natural systems [19]. 2. Bioenergy and microbial fuel cells: The production of electricity by Shewanella was shown early in this program (several years ago) to be dependent on the genes for extracellular electron transport (EET), and applied work involved the testing of various strains and conditions for the optimization of current production by the shewanellae [11,14,16]. 3. Identification of shewanellae strains: Based on similarities seen in genomic comparisons, a rapid method was employed for distinguishing between shewanellae strains [17]. Interactions with other laboratories: This grant was an extension of a grant involving the so-called ?Shewanella Federation?, and as such, a number of our publications were joint with other members of this group. The groups included: 1. Pacific Northwest Laboratories ? 2. Oak Ridge National Labs 3. Michigan State University 4. University of Oklahoma 5. Naval Research Laboratory, Washington DC 6. Burnham Medical Research Institute, San Diego 7. J. Craig Venter Institute, San Diego Education: Graduate Students: Michael Waters, Ph.D. ? at NIST, Washington D.C. Lewis Hsu, Ph.D. ? at NRL, San Diego Howard Harris, Ph.D. ? Postdoc at University, France Everett Salas, Ph.D. ? Scientist at Chevron McLean, Jeffrey, Ph.D. ? Scientist at J. Craig Venter Institute McCrow, John, Ph.D. ? Scientist at J. Craig Venter Institute Postdocs: Mohamed El-Naggar ? Professor of Physics, USC Jinjun Kan ? Senior Researcher at Undergraduatges: During this year, we had

  3. Prevalence of microcephaly in Europe: population based study

    PubMed Central

    Rankin, Judith; Garne, Ester; Loane, Maria; Greenlees, Ruth; Addor, Marie-Claude; Arriola, Larraitz; Barisic, Ingeborg; Bergman, Jorieke E H; Csaky-Szunyogh, Melinda; Dias, Carlos; Draper, Elizabeth S; Gatt, Miriam; Khoshnood, Babak; Klungsoyr, Kari; Kurinczuk, Jennifer J; Lynch, Catherine; McDonnell, Robert; Nelen, Vera; Neville, Amanda J; O’Mahony, Mary T; Pierini, Anna; Randrianaivo, Hanitra; Rissmann, Anke; Tucker, David; Verellen-Dumoulin, Christine; de Walle, Hermien E K; Wellesley, Diana; Wiesel, Awi; Dolk, Helen

    2016-01-01

    Objectives To provide contemporary estimates of the prevalence of microcephaly in Europe, determine if the diagnosis of microcephaly is consistent across Europe, and evaluate whether changes in prevalence would be detected using the current European surveillance performed by EUROCAT (the European Surveillance of Congenital Anomalies). Design Questionnaire and population based observational study. Setting 24 EUROCAT registries covering 570 000 births annually in 15 countries. Participants Cases of microcephaly not associated with a genetic condition among live births, fetal deaths from 20 weeks’ gestation, and terminations of pregnancy for fetal anomaly at any gestation. Main outcome measures Prevalence of microcephaly (1 Jan 2003-31 Dec 2012) analysed with random effects Poisson regression models to account for heterogeneity across registries. Results 16 registries responded to the questionnaire, of which 44% (7/16) used the EUROCAT definition of microcephaly (a reduction in the size of the brain with a skull circumference more than 3 SD below the mean for sex, age, and ethnic origin), 19% (3/16) used a 2 SD cut off, 31% (5/16) were reliant on the criteria used by individual clinicians, and one changed criteria between 2003 and 2012. Prevalence of microcephaly in Europe was 1.53 (95% confidence interval 1.16 to 1.96) per 10 000 births, with registries varying from 0.4 (0.2 to 0.7) to 4.3 (3.6 to 5.0) per 10 000 (χ2=338, df=23, I2=93%). Registries with a 3 SD cut off reported a prevalence of 1.74 per 10 000 (0.86 to 2.93) compared with those with the less stringent 2 SD cut off of 1.21 per 10 000 (0.21 to 2.93). The prevalence of microcephaly would need to increase in one year by over 35% in Europe or by over 300% in a single registry to reach statistical significance (P<0.01). Conclusions EUROCAT could detect increases in the prevalence of microcephaly from the Zika virus of a similar magnitude to those observed in Brazil. Because of the rarity

  4. A Study on Improving Information Processing Abilities Based on PBL

    ERIC Educational Resources Information Center

    Kim, Du Gyu; Lee, JaeMu

    2014-01-01

    This study examined an instruction method for the improvement of information processing abilities in elementary school students. Current elementary students are required to develop information processing abilities to create new knowledge for this digital age. There is, however, a shortage of instruction strategies for these information processing…

  5. Thesaurus-Based Automatic Indexing: A Study of Indexing Failure.

    ERIC Educational Resources Information Center

    Caplan, Priscilla Louise

    This study examines automatic indexing performed with a manually constructed thesaurus on a document collection of titles and abstracts of library science master's papers. Errors are identified when the meaning of a posted descriptor, as identified by context in the thesaurus, does not match that of the passage of text which occasioned the…

  6. Feasibility study of algae-based Carbon Dioxide capture

    EPA Science Inventory

    SUMMARY: The biomass of microalgae contains approximately 50% carbon, which is commonly obtained from the atmosphere, but can also be taken from commercial sources that produce CO2, such as coal-fired power plants. A study of operational demonstration projects is being undertak...

  7. Feasibility study of algae-based CO2 capture

    EPA Science Inventory

    The biomass of microalgae contains approximately 50% carbon, which is commonly obtained from the atmosphere, but can also be taken from commercial sources that produce CO2, such as coal-fired power plants. A study of operational demonstration projects is being undertaken to eval...

  8. Laser-ARPES studies of BSCCO-BASED cuprate superconductors

    NASA Astrophysics Data System (ADS)

    Douglas, J. F.; Koralek, J. D.; Sun, Z.; Plumb, N. C.; Wang, Q.; Reber, T. J.; Griffith, J. D.; Aiura, Y.; Oka, K.; Eisaki, H.; Dessau, D. S.; Devereaux, T. P.; Johnson, S. S.

    2007-03-01

    Utilizing 6 eV and 7 eV laser light, we have performed high-resolution ANGLE RESOLVED PHOTOEMISSION studies of the BSCCO family of superconductors. This higher resolution, in both energy and momentum, has allowed the observation of interesting new doping- and temperature-dependent features in the nodal and near nodal dispersions in these materials.

  9. Insect-Based Vision for Autonomous Vehicles: A Feasibility Study

    NASA Technical Reports Server (NTRS)

    Srinivasan, Mandyam V.

    1999-01-01

    The aims of the project were to use a high-speed digital video camera to pursue two questions: (1) To explore the influence of temporal imaging constraints on the performance of vision systems for autonomous mobile robots; (2) To study the fine structure of insect flight trajectories in order to better understand the characteristics of flight control, orientation and navigation.

  10. Insect-Based Vision for Autonomous Vehicles: A Feasibility Study

    NASA Technical Reports Server (NTRS)

    Srinivasan, Mandyam V.

    1999-01-01

    The aims of the project were to use a high-speed digital video camera to pursue two questions: i) To explore the influence of temporal imaging constraints on the performance of vision systems for autonomous mobile robots; To study the fine structure of insect flight trajectories with in order to better understand the characteristics of flight control, orientation and navigation.

  11. A Study of Multimedia Application-Based Vocabulary Acquisition

    ERIC Educational Resources Information Center

    Shao, Jing

    2012-01-01

    The development of computer-assisted language learning (CALL) has created the opportunity for exploring the effects of the multimedia application on foreign language vocabulary acquisition in recent years. This study provides an overview the computer-assisted language learning (CALL) and detailed a developing result of CALL--multimedia. With the…

  12. Feasibility study of algae-based CO2 capture

    EPA Science Inventory

    Abstract: The biomass of microalgae contains approximately 50% carbon, which is commonly obtained from the atmosphere, but can also be taken from commercial sources that produce CO2, such as coal-fired power plants. A study of operational demonstration projects is being underta...

  13. Telecommunication: Economic studies. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Reed, W. E.

    1980-06-01

    Research on economic evaluations of the telecommunications industry is cited. Communication satellites, common carriers, cable television, telephones systems, and television systems are all covered in the bibliography. Economic studies of the foreign telecommunications industry are included. This updated bibliography contains 280 abstracts, none of which are new entries to the previous edition.

  14. Telecommunication: Economic studies. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Reed, W. E.

    1980-06-01

    Research on economic evaluations of the telecommunications industry is cited. Communication satellites, common carriers, cable television, telephone systems, and television systems are all covered in the bibliography. Economic studies of the foreign telecommunications industry are included. This updated bibliography contains 60 abstracts, 36 of which are new entries to the previous edition.

  15. Web-Based Exchange of Views Enhances "Global Studies"

    ERIC Educational Resources Information Center

    Ahamer, Gilbert; Kumpfmuller, Karl A.; Hohenwarter, Michaela

    2011-01-01

    Purpose: The aim of this article is to present the development-oriented Master's curriculum "Global Studies" (GS) at the University of Graz, Austria, as an example of interdisciplinary academic training with the purpose of fostering inter-"cultural" understanding. It aims to show that scientific disciplines can be understood as "cultures of…

  16. A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

    ERIC Educational Resources Information Center

    Ultay, Neslihan; Calik, Muammer

    2012-01-01

    Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords "context-based", "contextual learning" and "chemistry…

  17. Studying Light in the Fifth Grade: A Case Study of Text-Based Science Teaching. Research Series No. 129.

    ERIC Educational Resources Information Center

    Slinger, Lucille A.; And Others

    This study documents text-based science instruction as it actually occurred in the classroom of a fifth-grade teacher teaching the unit on light found in "Exploring Science" by M.K. Blecha, P.C. Gega, and M. Green (1979, Laidlaw Brothers). The study, focusing on the nature of and reasons for the teacher's successes and failures, examined the…

  18. An instrument for the assessment of diarrhoeal severity based on a longitudinal community-based study

    PubMed Central

    Lee, Gwenyth; Peñataro Yori, Pablo; Paredes Olortegui, Maribel; Caulfield, Laura E; Sack, David A; Fischer-Walker, Christa; Black, Robert E; Kosek, Margaret

    2014-01-01

    Objective Diarrhoea is a significant contributer to morbidity and is among the leading causes of death of children living in poverty. As such, the incidence, duration and severity of diarrhoeal episodes in the household are often key variables of interest in a variety of community-based studies. However, there currently exists no means of defining diarrhoeal severity that are (A) specifically designed and adapted for community-based studies, (B) associated with poorer child outcomes and (C) agreed on by the majority of researchers. Clinical severity scores do exist and are used in healthcare settings, but these tend to focus on relatively moderate-to-severe dehydrating and dysenteric disease, require trained observation of the child and, given the variability of access and utilisation of healthcare, fail to sufficiently describe the spectrum of disease in the community setting. Design Longitudinal cohort study. Setting Santa Clara de Nanay, a rural community in the Northern Peruvian Amazon. Participants 442 infants and children 0–72 months of age. Main outcome measures Change in weight over 1-month intervals and change in length/height over 9-month intervals. Results Diarrhoeal episodes with symptoms of fever, anorexia, vomiting, greater number of liquid stools per day and greater number of total stools per day were associated with poorer weight gain compared with episodes without these symptoms. An instrument to measure the severity was constructed based on the duration of these symptoms over the course of a diarrhoeal episode. Conclusions In order to address limitations of existing diarrhoeal severity scores in the context of community-based studies, we propose an instrument comprised of diarrhoea-associated symptoms easily measured by community health workers and based on the association of these symptoms with poorer child growth. This instrument can be used to test the impact of interventions on the burden of diarrhoeal disease. PMID:24907244

  19. FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.

    SciTech Connect

    GALLARDO,J.C.; OZAKI,S.; PALMER,R.B.; ZISMAN,M.

    2001-06-30

    The concept of using a muon storage ring to provide a well characterized beam of muon and electron neutrinos (a Neutrino Factory) has been under study for a number of years now at various laboratories throughout the world. The physics program of a Neutrino Factoryis focused on the relatively unexplored neutrino sector. In conjunction with a detector located a suitable distance from the neutrino source, the facility would make valuable contributions to the study of neutrino masses and lepton mixing. A Neutrino Factory is expected to improve the measurement accuracy of sin{sup 2}(2{theta}{sub 23}) and {Delta}m{sup 2}{sub 32} and provide measurements of sin{sup 2}(2{theta}{sub 13}) and the sign of {Delta}m{sup 2}{sub 32}. It may also be able to measure CP violation in the lepton sector.

  20. Finite element based optimization study on hydroformed stepped tube

    NASA Astrophysics Data System (ADS)

    Harisankar, K. R.; Omar, A.; Narasimhan, K.

    2016-08-01

    Tube hydroforming process is an advanced manufacturing process in which tube is placed in between the dies and deformed with the help of hydraulic pressure. A sound tube hydroformed part depends upon die conditions, material properties and process conditions. In this work, a finite element study, along with response surface methodology (RSM) for designing the simulation, has been used to construct models with loading path, friction, anisotropic index, strain hardening exponent and tube thickness. The responses studied are the die corner radius filling and strain non-uniformity index (SNI) chosen in each step of the tube with maximum 30% thinning as stopping criteria. The factors effect and their interactions on each response were determined and analysed.

  1. Dilatometer study of rapidly solidified aluminium-silicon based alloys

    NASA Astrophysics Data System (ADS)

    Varga, B.; Fazakas, E.; Hargitai, H.; Varga, L. K.

    2009-01-01

    Aluminum-Silicon alloys are sought in a large number of automotive and aerospace applications due to their low coefficient of thermal expansion and high wear resistance. The present study focused on structural transformations as a function of the temperature of rapidly solidified hypereutectic Al100-xSix (x = 12, 22 and 40) alloys. Different structures out of equilibrium have been obtained after casting in sand, graphite and copper moulds and by melt spinning. The retained Si content in supersaturated alpha Al and the precipitation of Si is discussed in the light of the dilatometer studies [1, 2, 3] complemented by metallographic microscopy, XRD and DSC [4] measurements. A Kissinger analysis was used to determine the activation energy for the precipitation of supersaturated Si content.

  2. Pharmacokinetic study of medicinal polymers: models based on dextrans

    SciTech Connect

    Kulakov, V.N.; Pimenova, G.N.; Matveev, V.A.; Sedov, V.V.; Vasil'ev, A.E.

    1986-09-01

    The authors study the pharmacokinetics of dextrans with various molecular masses modified by fluorescein isothiocyanate (FITC) using a radioisotope method. The radionuclide /sup 125/I was selectively bound to a FITC residue attached to the polysaccharide by electrochemical iodination under potentiostatic conditions. In the experiments, dextrans modified by FITC were labeled with /sup 125/I (DF-/sup 125/I) by electrochemical iodination. The separation of DF-/sup 125/I and FITC from ionic forms of the radionuclide not bound to the polymer was carried out. The properties of the samples obtained are presented. The radioactivity accumulated in the rate organs and urine studied are shown. The features of DF-/sup 125/I behavior in the blood and liver are examined.

  3. Lunar base surface mission operations. Lunar Base Systems Study (LBSS) task 4.1

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The purpose was to perform an analysis of the surface operations associated with a human-tended lunar base. Specifically, the study defined surface elements and developed mission manifests for a selected base scenario, determined the nature of surface operations associated with this scenario, generated a preliminary crew extravehicular and intravehicular activity (EVA/IVA) time resource schedule for conducting the missions, and proposed concepts for utilizing remotely operated equipment to perform repetitious or hazardous surface tasks. The operations analysis was performed on a 6 year period of human-tended lunar base operation prior to permanent occupancy. The baseline scenario was derived from a modified version of the civil needs database (CNDB) scenario. This scenario emphasizes achievement of a limited set of science and exploration objectives while emplacing the minimum habitability elements required for a permanent base.

  4. [Cataract: based on A-bomb survivor studies].

    PubMed

    Neriishi, Kazuo

    2012-03-01

    Until now, the radiation protection community had assumed that only high doses of 2 Gy or more cause cataracts. However, new data from the atomic-bomb (A-bomb) survivors suggest that the dose threshold for both minor opacities and vision limiting cataracts may be below 1 Gy. Other studies have shown similar results in recent years. In 2011, the International Commission on Radiological Protection (ICRP) revised their guidelines for permissible occupational and medical exposures to the eye.

  5. Evidenced-based review of clinical studies on endodontic diagnosis.

    PubMed

    2009-08-01

    The practice of endodontics requires excellence in diagnostic skills. The importance of this topic has been underscored by a recent 2008 AAE-sponsored symposium on endodontic diagnosis, which will be highlighted in a special issue of the Journal of Endodontics. In this minireview, we focus on recent clinical studies that emphasize different aspects related to the diagnosis of disorders of the pulp-dentin complex. PMID:19631854

  6. [Cataract: based on A-bomb survivor studies].

    PubMed

    Neriishi, Kazuo

    2012-03-01

    Until now, the radiation protection community had assumed that only high doses of 2 Gy or more cause cataracts. However, new data from the atomic-bomb (A-bomb) survivors suggest that the dose threshold for both minor opacities and vision limiting cataracts may be below 1 Gy. Other studies have shown similar results in recent years. In 2011, the International Commission on Radiological Protection (ICRP) revised their guidelines for permissible occupational and medical exposures to the eye. PMID:22514923

  7. Drug-DNA Interaction Studies of Acridone-Based Derivatives.

    PubMed

    Thimmaiah, Kuntebomanahalli; Ugarkar, Apoorva G; Martis, Elvis F; Shaikh, Mushtaque S; Coutinho, Evans C; Yergeri, Mayur C

    2015-01-01

    N10-alkylated 2-bromoacridones are a novel series of potent antitumor compounds. DNA binding studies of these compounds were carried out using spectrophotometric titrations, Circular dichroism (CD) measurements using Calf Thymus DNA (CT DNA). The binding constants were identified at a range of K=0.3 to 3.9×10(5) M(-1) and the percentage of hypochromism from the spectral titrations at 28-54%. This study has identified a compound 9 with the good binding affinity of K=0.39768×10(5) M(-1) with CT DNA. Molecular dynamics (MD) simulations have investigated the changes in structural and dynamic features of native DNA on binding to the active compound 9. All the synthesized compounds have increased the uptake of Vinblastine in MDR KBChR-8-5 cells to an extent of 1.25- to1.9-fold than standard modulator Verapamil of similar concentration. These findings allowed us to draw preliminary conclusions about the structural features of 2-bromoacridones and further chemical enhancement will improve the binding affinity of the acridone derivatives to CT-DNA for better drug-DNA interaction. The molecular modeling studies have shown mechanism of action and the binding modes of the acridones to DNA.

  8. Detection of electronically equivalent tautomers of adenine base: DFT study

    SciTech Connect

    Siddiqui, Shamoon Ahmad; Bouarissa, Nadir; Rasheed, Tabish; Al-Assiri, M.S.; Al-Hajry, A.

    2014-03-01

    Graphical abstract: - Highlights: • DFT calculations have been performed on adenine and its rare tautomer Cu{sup 2+} complexes. • Interaction of A-Cu{sup 2+} and rA-Cu{sup 2+} complexes with AlN modified fullerene (C{sub 60}) have been studied briefly. • It is found that AlN modified C{sub 60} could be used as a nanoscale sensor to detect these two A-Cu{sup 2+} and rA-Cu{sup 2+} complexes. - Abstract: In the present study, quantum chemical calculations were carried out to investigate the electronic structures and stabilities of adenine and its rare tautomer along with their Cu{sup 2+} complexes. Density Functional Theory (B3LYP method) was used in all calculations. The two Cu{sup 2+} complexes of adenine have almost similar energies and electronic structures; hence, their chemical differentiation is very difficult. For this purpose, interactions of these complexes with AlN modified fullerene (C{sub 60}) have been studied. Theoretical investigations reveal that AlN-doped C{sub 60} may serve as a potentially viable nanoscale sensor for detection of the two Cu{sup 2+} complexes of adenine.

  9. Web-based tracking methods in longitudinal studies.

    PubMed

    Williams, Izaak L; O'Donnell, Clifford R

    2014-08-01

    The use of online resources to reduce the attrition of program participants in longitudinal studies is examined. Higher-risk individuals, those involved in illegal activities, and females with last name changes are typically more difficult to locate. The effectiveness of using online resources for these participants is addressed. These resources include social networking sites, people-finder search engines, telephone and address directories, judicial records, and death records. The strengths and limitations of these resources are presented and discussed. Longitudinal studies using these resources are examined to evaluate their successful follow-up rates. The results of these studies indicate that participant characteristics are more important to successful follow-up than the length of time since participation or sample size. The use of multiple online sites increased follow-up rates, especially for those who are typically difficult to locate. The variables and websites to consider are discussed, and six lessons learned are offered. The prospective use of online participant involvement is especially important for successful longitudinal evaluation and program planning. PMID:24769078

  10. Electroresistance and field effect studies on manganite based heterostructure

    SciTech Connect

    Solanki, P. S.; Khachar, Uma; Vagadia, Megha; Ravalia, Ashish; Katba, Savan; Kuberkar, D. G.

    2015-04-14

    Electronic properties of manganites are significantly important for various spintronic applications such as microelectronics, magnetic data storage, communication technologies, and memory devices. Influence of applied electric field on the room temperature charge transport in ZnO/La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrNb{sub 0.002}Ti{sub 0.998}O{sub 3} (SNTO) heterostructure has been investigated using field effect studies. Large negative and positive electroresistance has been observed in heterostructure under various possible circuit geometries. Field effect studies have been carried out using three different circuit geometries, namely: (i) ZnO as a control electrode (E{sub LZ}), (ii) SNTO as a control electrode (E{sub LS}), and (iii) shorted ZnO and SNTO as control electrodes (E{sub LZS}). For this, channel electric field (E{sub CH}) dependent variation in channel resistance (R{sub C}) (of manganite channel) and I-V (across manganite channel) under various control fields (E{sub C}) have been studied. Variation in barrier height (Φ{sub B}) with control field (E{sub C}) for different geometries has been discussed.

  11. Oviposition behaviour of Phlebotomus argentipes - A laboratory-based study

    PubMed Central

    Kumar, Vijay; Rama, Aarti; Kesari, Shreekant; Bhunia, Gouri Sankar; Dinesh, Diwakar Singh; Das, Pradeep

    2013-01-01

    The breeding habitat of sandflies is a little studied and poorly understood phenomenon. More importantly, oviposition behaviour is a largely neglected aspect of sandfly biology and this knowledge gap further undermines our understanding of the biology of sandflies. Pheromones released by the eggs play an important role in identifying good sites for oviposition by female insects. Several recent studies have examined the oviposition pheromone. The present study provides a preliminary report on the oviposition behaviour of Phlebotomus argentipes, the only vector of kala-azar (or visceral leishmaniasis) on the Indian sub-continent. Sandflies prefer to oviposit their eggs on surfaces that contain organic substances, especially substances with an odour of decaying animal products and the remains of conspecific eggs. The results presented here suggest that the odour released by the organic substances of old sandfly colony remains that contain dead flies, old unhatched eggs, larval food containing vertebrate faeces, frass and other organic matter serves as an attractant for the ovipositing females of P. argentipes and hence greatly increases the number of oviposited eggs compared to eggs deposited in controlled oviposition pots. This result will be helpful in maintaining an efficient colony of P. argentipes and may be a promising tool for monitoring and controlling the target insect as part of a synergistic approach. PMID:24141963

  12. Integrated genome-based studies of Shewanella ecophysiology

    SciTech Connect

    Segre Daniel; Beg Qasim

    2012-02-14

    This project was a component of the Shewanella Federation and, as such, contributed to the overall goal of applying the genomic tools to better understand eco-physiology and speciation of respiratory-versatile members of Shewanella genus. Our role at Boston University was to perform bioreactor and high throughput gene expression microarrays, and combine dynamic flux balance modeling with experimentally obtained transcriptional and gene expression datasets from different growth conditions. In the first part of project, we designed the S. oneidensis microarray probes for Affymetrix Inc. (based in California), then we identified the pathways of carbon utilization in the metal-reducing marine bacterium Shewanella oneidensis MR-1, using our newly designed high-density oligonucleotide Affymetrix microarray on Shewanella cells grown with various carbon sources. Next, using a combination of experimental and computational approaches, we built algorithm and methods to integrate the transcriptional and metabolic regulatory networks of S. oneidensis. Specifically, we combined mRNA microarray and metabolite measurements with statistical inference and dynamic flux balance analysis (dFBA) to study the transcriptional response of S. oneidensis MR-1 as it passes through exponential, stationary, and transition phases. By measuring time-dependent mRNA expression levels during batch growth of S. oneidensis MR-1 under two radically different nutrient compositions (minimal lactate and nutritionally rich LB medium), we obtain detailed snapshots of the regulatory strategies used by this bacterium to cope with gradually changing nutrient availability. In addition to traditional clustering, which provides a first indication of major regulatory trends and transcription factors activities, we developed and implemented a new computational approach for Dynamic Detection of Transcriptional Triggers (D2T2). This new method allows us to infer a putative topology of transcriptional dependencies

  13. Atopic dermatitis is a serious health problem in Poland. Epidemiology studies based on the ECAP study

    PubMed Central

    Raciborski, Filip; Lipiec, Agnieszka; Tomaszewska, Aneta; Lusawa, Adam; Samel-Kowalik, Piotr; Walkiewicz, Artur; Krzych, Edyta; Komorowski, Jarosław; Samoliński, Bolesław

    2015-01-01

    Introduction Global epidemiological studies have revealed considerable geographical differences in prevalence of atopic dermatitis (AD). Aim To present the epidemiology of AD, risk factors and co-occurrence of allergic diseases in the Polish population. Material and methods The present paper is a part of the Epidemiology of Allergic Disorders in Poland study. We studied 22 703 participants by ECRHS/ISAAC questionnaire; 18 617 (53.8% female, 24.2% 6–7 y.o., 25.4% 13–14 y.o., 50.4% 20–44 y.o.) completed questionnaires were accepted. Four thousand seven hundred and eighty-three participants (25.7%) have undergone a medical examination. Results Atopic dermatitis was diagnosed in 3.91% (6–7 y.o. 5.34%, 13–14 y.o. 4.3%, adults 3.02%), more often in females (OR = 1.52; 95% CI: 0.56–0.77), in the cities (OR = 2.23; 95% CI: 1.61–3.09), in mothers (OR = 2.07; 95% CI: 1.72–2.48) and fathers (OR = 2.00; 95% CI: 1.61–2.49) with atopy, higher education (OR = 1.61; 95% CI: 1.11–2.32) and economic status (OR = 1.35; 95% CI: 1.04–1.74). The highest prevalence was found in Katowice (4.89%) and lowest in rural areas (1.9%). Coexisting AD and allergic rhinitis (AR) was found in 26.17%, AR and asthma in 9.09% and AD, AR and asthma in 14.6%. Atopic dermatitis was diagnosed by allergologists in 6.5% (6–7 y.o. 8.7%, 13–14 y.o. 9.0%, adults 3.6%). Most diagnoses were made in Poznan (16.76%) and smallest in rural area (3.67%). 78.8% of subjects were diagnosed with AD for the first time although they had earlier experienced its symptoms. Conclusions Atopic dermatitis prevalence in Poland is below the mean rate for Europe, but the risk factor profile is similar to other countries. Atopic dermatitis is more frequent in well-educated females with atopic parents and high socioeconomic status and who live in a city. PMID:25821420

  14. Interferometer-Based Studies of Quantum Hall Phenomena

    NASA Astrophysics Data System (ADS)

    McClure, Douglas Templeton, III

    The fractional quantum Hall (FQH) effect harbors a wealth of unique phenomena, many of which remain mysterious. Of particular interest is the predicted existence of quasi-particles with unusual topological properties, especially in light of recent proposals to observe these properties using electronic interferometers. An introduction to quantum Hall physics and electronic interferometry is given in Chapter 1 of this thesis. The remaining chapters, summarized below, describe a set of experiments in which FQH systems are studied using electronic Fabry-Perot interferometry and related techniques. Since prior studies of electronic Fabry-Perot interferometers revealed unexpected behavior even in the integer quantum Hall (IQH) regime, we began our measurements there. Our initial experiment, presented in Chapter 2, disentangles signatures of Coulomb interaction effects from those of Aharonov-Bohm (AB) interference and provides the first measurement of pure AB interference in these devices. In our next experiment, presented in Chapter 3, we measure AB interference oscillations as a function of an applied dc bias, use their period to study the velocity of the interfering electrons, and study how the oscillations decay as a function of bias and magnetic field. Moving to the FQH regime, applying a similar-sized bias to a quantum point contact leads to long-lasting changes in the strengths and positions of FQH plateaus. The involvement of lattice nuclear spins in this effect, suggested by the long persistence times, is confirmed using NMR-type measurements. Although the exact physical process responsible for the effect remains unclear, its filling-factor dependence provides a striking illustration of composite fermion physics. These measurements are described in Chapter 4. In certain devices, interference oscillations associated with several FQH states are observed. Interpretation of their magnetic-field and gate-voltage periods provides a measurement of quasi-particle charge

  15. Ethical issues in human genome epidemiology: a case study based on the Japanese American Family Study in Seattle, Washington.

    PubMed

    Austin, Melissa A

    2002-04-01

    Recent completion of the draft sequence of the human genome has been greeted with both excitement and skepticism, and the potential of this accomplishment for advancing public health has been tempered by ethical concerns about the protection of human subjects. This commentary explores ethical issues arising in human genome epidemiology by using a case study approach based on the ongoing Japanese American Family Study at the University of Washington in Seattle (1994-2003). Ethical issues encountered in designing the study, collecting the data, and reporting the study results are considered. When developing studies, investigators must consider whether to restrict the study to specific racial or ethnic groups and whether community involvement is appropriate. Once the study design is in place, further ethical issues emerge, including obtaining informed consent for DNA banking and protecting the privacy and confidentiality of family members. Finally, investigators must carefully consider whether to report genotype results to study participants and whether pedigrees illustrating the results of the study will be published. Overall, the promise of genomics for improving public health must be pursued based on the fundamental ethical principles of respect for persons, beneficence, and justice.

  16. Epidemiological study of chronic kidney disease progression: a large-scale population-based cohort study.

    PubMed

    Vejakama, Phisitt; Ingsathit, Atiporn; Attia, John; Thakkinstian, Ammarin

    2015-01-01

    The prognostic information about CKD progression, particularly for GFR categories 1 and 2, is still limited. This cohort was therefore conducted to determine the CKD progression using a competing risk approach. We conducted a retrospective cohort study linking community health screening with hospitals and death registry data in a province of Thailand, from 1997 to 2011. A competing risk model was applied by treating death as a competing risk factor to estimate 2-, 5-, and 10-year probability of kidney failure and median time for CKD progression from lower to higher GFR category. There were 17,074 non-diabetic and 15,032 diabetic CKD subjects. Diabetic subjects progressed more rapidly through GFR categories with the median times for CKD progression from GFR categories G1 to G2, G2 to G3a, G3a to G3b, G3b to G4, and G4 to G5 of 4.4, 6.1, 4.9, 6.3, and 9.0 years, respectively. Non-diabetic subjects took longer to progress with the corresponding median time of 9.4, 14.0, 11.0, 13.8, and >14.3 years. After adjusting for confounders, diabetic subjects were 49% (cause-specific hazard ratio ((c)HR) = 1.49, 95% CI: 1.37, 1.62) more likely to develop kidney failure than non-diabetic subjects. Albuminuria categories A3 and A2 were, respectively, 3.40 (95% CI: 3.07, 3.76) and 1.71 (95% CI: 1.53, 1.92) higher risk of kidney failure when compared to A1. For each albumin category, death rate increased as albuminuria increased particularly in diabetic subjects, which was approximately 2 times higher in A3 compared to A1. Considering GFR category, it gradually increased from G1 to G4 and sharply increased from G4 to G5 in both non-diabetic and diabetic subjects. This study has quantified CKD progression in an Asian population within ordinary practice. Diabetic subjects progress through GFR and albuminuria categories and reach kidney failure about twice as rapidly as non-diabetic subjects.

  17. Virtual-reality-based system for controlled study of cataplexy

    NASA Astrophysics Data System (ADS)

    Augustine, Kurt E.; Cameron, Bruce M.; Camp, Jon J.; Krahn, Lois E.; Robb, Richard A.

    2002-05-01

    Cataplexy is a sudden loss of voluntary muscle control experienced by narcolepsy patients. It is usually triggered by strong, spontaneous emotions and is more common in times of stress. The Sleep Disorders Unit and the Biomedical Imaging Resource at Mayo Clinic are developing interactive display technology for reliably inducing cataplexy during clinical monitoring. The project is referred to as the Cataplexy/Narcolepsy Activation Program, or CatNAP. We have developed an automobile driving simulation that introduces humorous, surprising, and stress-inducing events and objects as the patient attempts to navigate a vehicle through a virtual town. The patient wears a head-mounted display and controls the vehicle via a driving simulator steering wheel and pedal cluster. As the patient attempts to drive through the town, various objects, sounds or conditions occur that distract, startle, frustrate or amuse. These responses may trigger a cataplectic episode, which can then be clinically evaluated. We believe CatNAP is a novel and innovative example of the effective application of virtual reality technology to study an important clinical problem that has resisted previous approaches. An evaluation phase with volunteer patients previously diagnosed with cataplexy has been completed. The prototype system is being prepared for a full clinical study.

  18. Female employment and fertility: a study based on Chilean data.

    PubMed

    Peek, P

    1975-01-01

    Conflicting studies bring into question the hypothesis that increased employment opportunities for women in the modern sector would reduce the population growth rate. To help clarify the situation, data from about 4000 families in central Chile, obtained from interviews in 1965, are used to test 3 hypotheses: 1) that in the traditional sector of the economy, young children do not adversely affect the mother's labor force participation; 2) that in the modern sector, child care reduces labor force participation unless there are relatives or older children to look after the young children; and 3) that young children also have a positive influence on female employment in that they increase the need for added income. This would be particularly true in the traditional sector where average household income is lower. All hypotheses were proved true by the data. Furthermore, the positive effect on the mother's employment of a larger family size proved to be true in the modern sector as well as the traditional sector. The study indicates that if a country's objective is to lower the population growth rate, a population planning program relying on higher rates of fe male employment will have to be accompanied by other socioeconomic policies intended to achieve a higher level of economic development.

  19. Depressive symptoms and sleep: a population-based polysomnographic study.

    PubMed

    Castro, Laura Siqueira; Castro, Juliana; Hoexter, Marcelo Queiroz; Quarantini, Lucas Castro; Kauati, Adriana; Mello, Luiz Eugenio; Santos-Silva, Rogerio; Tufik, Sergio; Bittencourt, Lia

    2013-12-30

    The goals of the present study were to determine the prevalence of depression in the adult population of Sao Paulo, Brazil and to explore the relationship among sociodemographic, physical and psychological factors, sleep-related symptoms and polysomnography parameters. Participants of a cross-sectional study (N = 1101) were administered questionnaires and submitted to polysomnography. A score > 20 in the Beck Depression Inventory was used to describe depression. Results revealed that the prevalence of depression was 10.9%. Estimates were higher in women and were significantly higher among housewives, non-workers and individuals with lower education and income. A combination of sleep-related symptoms and impaired quality of life was 2.5 times more frequent among depressed than non-depressed. Co-morbid insomnia and anxiety were positively associated to depressive symptomatology. There were no alterations in the polysomnography parameters, in either group. The occurrence of sleep apnea with values on the apnea-hypopnea index ≥ 5 was similar and frequent in both groups (around 30%). The findings suggest that depressive symptoms were associated with low education, low income, severe comorbid symptomatology, and impaired quality of life. Considering the high prevalence of sleep apnea, these results point to potential social and financial burdens associated with the depressive symptomatology and various sleep diagnoses.

  20. Nuclear-based methods for the study of selenium

    SciTech Connect

    Spyrou, N.M.; Akanle, O.A.; Dhani, A. )

    1988-01-01

    The essentiality of selenium to the human being and in particular its deficiency state, associated with prolonged inadequate dietary intake, have received considerable attention. In addition, the possible relationship between selenium and cancer and the claim that selenium may possess cancer-prevention properties have focused research effort. It has been observed in a number of studies on laboratory animals that selenium supplementation protects the animals against carcinogen-induced neoplastic growth in various organ sites, reduces the incidence of spontaneous mammary tumors, and suppresses the growth of transplanted tumor cells. In these research programs on the relationship between trace element levels and senile dementia and depression and the elemental changes in blood associated with selenium supplementation in a normal group of volunteers, it became obvious that in addition to establishing normal levels of elements in the population of interest, there was a more fundamental requirement for methods to be developed that would allow the study of the distribution of selenium in the body and its binding sites. The authors propose emission tomography and perturbed angular correlation as techniques worth exploring.

  1. Space-Based Solar Power Conversion and Delivery Systems Study. Volume 3: Microwave Power Transmission Studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The Microwave Fower Beam Ionosphere effects and critical interfaces between th Microwave Power Transmission System (MPTS) and the Satellite were studied as part of the NASA/MSFC continuing research on the feasibility of power transmission from geosynchronous orbit. Theoretical predications of ionospheric modifications produced by the direct interaction of the MPTS on the earth's upper atmosphere are used to determine their impact on the performance of the Microwave Power Beam and Pilot Beam System as well as on other RF systems effected by the ionosphere. A technology program to quantitatively define these interactions is developed. Critical interface areas between the MPTS and the satellite which could have a major impact on cost and performance of the power system are idenfified and analyzed. The areas selected include: use of either a 20 kV versus 40 kV Amplitron, thermal blockage effects of Amplitron heat radiation by the satellite structure, effect of dielectric carry-through structure on power beam, and effect of material sublimation on performance of the Amplitron in Geosynchronous Orbit.

  2. Object tracking based on harmony search: comparative study

    NASA Astrophysics Data System (ADS)

    Gao, Ming-Liang; He, Xiao-Hai; Luo, Dai-Sheng; Yu, Yan-Mei

    2012-10-01

    Visual tracking can be treated as an optimization problem. A new meta-heuristic optimal algorithm, Harmony Search (HS), was first applied to perform visual tracking by Fourie et al. As the authors point out, many subjects are still required in ongoing research. Our work is a continuation of Fourie's study, with four prominent improved variations of HS, namely Improved Harmony Search (IHS), Global-best Harmony Search (GHS), Self-adaptive Harmony Search (SHS) and Differential Harmony Search (DHS) adopted into the tracking system. Their performances are tested and analyzed on multiple challenging video sequences. Experimental results show that IHS is best, with DHS ranking second among the four improved trackers when the iteration number is small. However, the differences between all four reduced gradually, along with the increasing number of iterations.

  3. Experimental study of blast mitigating devices based on combined construction

    NASA Astrophysics Data System (ADS)

    Takayama, K.; Silnikov, M. V.; Chernyshov, M. V.

    2016-09-01

    A robust blast inhibiting bin is the most often used device for damage blast effects suppression. In particular, a top open cylindrical bin significantly reduces a fragmentation effect resulted from a detonation of an explosive device placed inside the bin. However, reduction of blast wave overpressure and impulse by such cylindrical bins is not sufficient [1]. A reasonable alternative to endless increase of height and thickness of robust blast inhibiting bins is a development of destructible inhibitors having no solid elements in their structure and, therefore, excluding secondary fragmentation. So, the family of "Fountain" inhibitors [2,3] localizes and suppresses damaging blast effects due to multiphase working system. The present study is analyzing data obtained in testing of prototypes of new combined inhibitors. Their structure combines robust elements (bottoms, side surfaces) with elements responsible for blast loads reduction due to multi-phase working system (top and low transverse embeddings) and fairings impeding wave propagation in undesirable directions.

  4. Student Classroom Misbehavior: An Exploratory Study Based on Teachers' Perceptions

    PubMed Central

    Sun, Rachel C. F.; Shek, Daniel T. L.

    2012-01-01

    This study aimed to examine the conceptions of junior secondary school student misbehaviors in classroom, and to identify the most common, disruptive, and unacceptable student problem behaviors from teachers' perspective. Twelve individual interviews with teachers were conducted. A list of 17 student problem behaviors was generated. Results showed that the most common and disruptive problem behavior was talking out of turn, followed by nonattentiveness, daydreaming, and idleness. The most unacceptable problem behavior was disrespecting teachers in terms of disobedience and rudeness, followed by talking out of turn and verbal aggression. The findings revealed that teachers perceived student problem behaviors as those behaviors involving rule-breaking, violating the implicit norms or expectations, being inappropriate in the classroom settings and upsetting teaching and learning, which mainly required intervention from teachers. PMID:22919297

  5. Budding yeast colony growth study based on circular granular cell

    NASA Astrophysics Data System (ADS)

    Aprianti, Devi; Khotimah, S. N.; Viridi, S.

    2016-08-01

    Yeast colony growth can be modelled by using circular granular cells, which can grow and produce buds. The bud growth angle can be set to regulate cell budding pattern. Cohesion force, contact force and Stokes force were adopted to accommodate the behaviour and interactions among cells. Simulation steps are divided into two steps, the explicit step is due to cell growing and implicit step for the cell rearrangement. Only in explicit step that time change was performed. In this study, we examine the influence of cell diameter growth time and reproduction time combination toward the growth of cell number and colony formation. We find a commutative relation between the cell diameter growth time and reproduction time to the specific growth rate. The greater value of the multiplication of the parameters, the smaller specific growth rate is obtained. It also shows a linear correlation between the specific growth rate and colony diameter growth rate.

  6. Perinatal mortality in Matlab, Bangladesh: a community-based study.

    PubMed

    Fauveau, V; Wojtyniak, B; Mostafa, G; Sarder, A M; Chakraborty, J

    1990-09-01

    Perinatal deaths, comprising stillbirths and deaths during the first week of life, were monitored over the eight-year period 1979 to 1986 in a rural Bangladeshi population of 196,000. The perinatal mortality rate was 75 per 1000 total births. The rate was 13% higher in males than females. Stillbirth and early neonatal mortality rates were 37 and 38 per 1000 total births, respectively. The major causes of perinatal deaths are presented, as well as some of the maternal determinants. During the period under study, perinatal mortality declined regularly and significantly over time in an area covered by an intensive Family Planning and Health Services programme, but not in the adjacent control area. This raises the issue of the impact of such a programme upon perinatal mortality, and the need to include a strong maternity care component into primary healthcare strategies if further reductions of perinatal mortality are to be achieved. PMID:2262255

  7. Physicochemical studies of chemosensor imidazole derivatives: DFT based ESIPT process

    NASA Astrophysics Data System (ADS)

    Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Jayamoorthy, Karunamoorthy

    2012-04-01

    A series of substituted imidazoles have been synthesized in very good yield under a solvent free condition using molecular iodine as the catalyst. An excited state intramolecular proton transfer (ESIPT) process in hydroxy imidazole has been studied using emission spectroscopy. DFT calculations on energy, dipole moment, charge distribution of the rotamers in the ground and excited states of the imidazole derivatives have been performed and discussed. DFT analysis about HOMO, HOMO-1, LUMO and LUMO+1 has been carried out and discussed. The energy barrier for the interconversion of two rotamers is too high in the excited state than the ground state that is shown by PES calculation. The molecular electrostatic potential surface (MEP) has also been employed to show the higher electron density at N(3) nitrogen. Fluorescence enhancement has been found in the presence of transition metal ions and this may result from the suppression of radiationless transitions from the n-π* state in the chemosensors.

  8. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    NASA Astrophysics Data System (ADS)

    Nagendra, K.; Babu, G. Satish; Reddy, C. Narayana; Gowda, Veeranna

    2011-07-01

    Glasses in the system xLi2SO4-20Li2O-(80-x) [80P2O5-20V2O5] (5⩾x⩾20 mol%) has been prepared by melt quenching method. Dc and ac conductivity has been studied over a wide range of frequency (10 Hz to 10 MHz) and temperature (298 K-523 K). The dc conductivity found to increase with increase of Li2SO4 concentration. The ac conductivities have been fitted to the Almond-West type single power law equation σ(ω) = σ(0)+Aωs where `s' is the power law exponent. The ac conductivity found to increase with increase of Li2SO4 concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

  9. Proper-Motion Based Kinematics Study of Galactic RR Lyraes

    NASA Astrophysics Data System (ADS)

    Dambis, Andrei K.; Berdnikov, Leonid N.; Rastorguev, Alexei S.; Zabolotskikh, Marina V.

    2016-08-01

    We use the UCAC4 and SDSS proper motions of about 7500 RR Lyrae type variables located within ~10 kpc from the Sun to study the dependence of their velocity ellipsoid on Galactocentric distance in the R G = 3-17 kpc interval. The radial velocity dispersion, σ VR , decreases from ~190 km/s at R G = 3.5-5.5 kpc down to ~100 km/s at R G = 13-15 kpc, and the σ VT /σ VR ratio remains virtually constant (σ VT /σ VR ~0.54-0.64) in the Galactocentric distance interval from R G = 4.5 kpc to R G = 10.5 kpc increasing to ~0.9 both toward the Galactic center and beyond R G = 11 kpc.

  10. Probabilistic thinking and death anxiety: a terror management based study.

    PubMed

    Hayslip, Bert; Schuler, Eric R; Page, Kyle S; Carver, Kellye S

    2014-01-01

    Terror Management Theory has been utilized to understand how death can change behavioral outcomes and social dynamics. One area that is not well researched is why individuals willingly engage in risky behavior that could accelerate their mortality. One method of distancing a potential life threatening outcome when engaging in risky behaviors is through stacking probability in favor of the event not occurring, termed probabilistic thinking. The present study examines the creation and psychometric properties of the Probabilistic Thinking scale in a sample of young, middle aged, and older adults (n = 472). The scale demonstrated adequate internal consistency reliability for each of the four subscales, excellent overall internal consistency, and good construct validity regarding relationships with measures of death anxiety. Reliable age and gender effects in probabilistic thinking were also observed. The relationship of probabilistic thinking as part of a cultural buffer against death anxiety is discussed, as well as its implications for Terror Management research.

  11. Study on the CO Oxidation over Ceria-Based Nanocatalysts

    NASA Astrophysics Data System (ADS)

    Piumetti, Marco; Andana, Tahrizi; Bensaid, Samir; Russo, Nunzio; Fino, Debora; Pirone, Raffaele

    2016-03-01

    A series of ceria nanocatalysts have been prepared to study the structure dependency of the CO oxidation reaction. The ceria samples with well-defined nanostructures (nanocubes/Ce-NC and nanorods/Ce-NR) have been prepared using the hydrothermal method. Mesoporous ceria (Ce-MES) and ceria synthesized with solution combustion technique (Ce-SCS) have also been prepared for comparison. The lowest CO oxidation temperature has been reached by using ceria nanocubes (Ce-NC). This high activity draws immense contributions from the highly reactive (100) and (110) surfaces of the truncated nanocubes. The Ce-MES and Ce-SCS samples, despite their high surface areas, are unable to outdo the activity of Ce-NC and Ce-NR due to the abundant presence of (111) crystalline planes. This finding confirms the structure sensitivity of CO oxidation reaction catalyzed with ceria.

  12. Trauma Boot Camp: A Simulation-Based Pilot Study

    PubMed Central

    Moftakhar, Yasmin; Dobbins IV, Arthur L; Khan, Ramisha; Dasgupta, Rahul; Blanda, Rachel; Marchand, Tiffany; Ahmed, Rami

    2016-01-01

    Introduction: Interns are often unprepared to effectively communicate in the acute trauma setting. Despite the many strengths of the Advanced Trauma Life Support (ATLS) program, the main shortcoming within the course is the deficiency of teamwork and leadership training. In this study, we describe the creation of an interdisciplinary boot camp in which interns' basic trauma knowledge, level of confidence, and teamwork skills are assessed. Methods: We designed a one-day, boot camp curriculum for interns of various specialties with the purpose of improving communication and teamwork skills for effective management of acute trauma patients. Our curriculum consisted of a one-day, twelve-hour experience, which included trauma patient simulations, content expert lectures, group discussion of video demonstrations, and skill development workstations. Baseline and acquired knowledge were assessed through the use of confidence surveys, cognitive questionnaires, and a validated evaluation tool of teamwork and leadership skills for trauma Results: Fifteen interns entered the boot camp with an overall confidence score of 3.2 (1-5 scale) in the management of trauma cases. At the culmination of the study, there was a significant increase in the overall confidence level of interns in role delegation, leadership, Crisis Resource Management (CRM) principles, and in the performance of primary and secondary surveys. No significant changes were seen in determining and effectively using the Glasgow Coma Scale, Orthopedic splinting/reduction skills, and effective use of closed-loop communication. Conclusion: An intensive one-day trauma boot camp demonstrated significant improvement in self-reported confidence of CRM concepts, role delegation, leadership, and performance of primary and secondary surveys. Despite the intensive curriculum, there was no significant improvement in overall teamwork and leadership performance during simulated cases. Our boot camp curriculum offers educators a

  13. Factors affecting outdoor exposure in winter: population-based study

    NASA Astrophysics Data System (ADS)

    Mäkinen, Tiina M.; Raatikka, Veli-Pekka; Rytkönen, Mika; Jokelainen, Jari; Rintamäki, Hannu; Ruuhela, Reija; Näyhä, Simo; Hassi, Juhani

    2006-09-01

    The extent of outdoor exposure during winter and factors affecting it were examined in a cross-sectional population study in Finland. Men and women aged 25-74 years from the National FINRISK 2002 sub-study ( n=6,591) were queried about their average weekly occupational, leisure-time and total cold exposure during the past winter. The effects of gender, age, area of residence, occupation, ambient temperature, self-rated health, physical activity and education on cold exposure were analysed. The self-reported median total cold exposure time was 7 h/week (8 h men, 6 h women),<1 h/week (2 h men, 0 h women) at work, 4 h/week (5 h men, 4 h women) during leisure time and 1 h/week (1 h men, 1.5 h women) while commuting to work. Factors associated with increased occupational cold exposure among men were: being employed in agriculture, forestry and industry/mining/construction or related occupations, being less educated and being aged 55-64 years. Factors associated with increased leisure-time cold exposure among men were: employment in industry/mining/construction or related occupations, being a pensioner or unemployed, reporting at least average health, being physically active and having college or vocational education. Among women, being a housewife, pensioner or unemployed and engaged in physical activity increased leisure-time cold exposure, and young women were more exposed than older ones. Self-rated health was positively associated with leisure time cold exposure in men and only to a minor extent in women. In conclusion, the subjects reported spending 4% of their total time under cold exposure, most of it (71%) during leisure time. Both occupational and leisure-time cold exposure is greater among men than women.

  14. [IR and Raman spectra studies of Rotundine based on DFT].

    PubMed

    Li, Jun-Ping; Zhou, Guang-Ming; Zhang, Li-Jun; Cheng, Hong-Mei; Qin, Hong-Ying

    2014-11-01

    Infrared spectroscopy (IR), the normal Raman spectroscopy (NRS) and the surface enhanced Raman spectroscopy (SERS) in new Ag/Cu nanomaterial of Rotundine were studied in the present paper. The IR and the NRS of Rotundine were calculated by the density functional theory (DFT) using B3LYP/6-311+G(d, p), then the spectral intensity graph of Rotundine were given. The vibrational peaks were assigned comprehensively by the visualization software of Gauss view 5. 0. Rotundine has obvious infrared and Raman vibrational peak in the wave number range of 3 300-2500 and 1 800-600 cm(-1). SnCl2 and PVP was used as capping agent for the silver nanoparticles in SERS of Rotundine. Finally, by using the method of cyclic immersion well dispersed silver nanoparticles was obtained and achieved good enhancement effect. This molecule acquired strong selective enhancement vibration peak, In the wave number ranges of 1 500-1 400 and 1 000-700 cm(-1) the enhancement effect is most obvious. After analyzed, the methylene of this molecule is adsorbed on the silver nanoparticles surface and the angle between the benzene ring and the silver substrate is close to 90 degrees. The theoretically calculated spectra of Rotundine are consistent with the obtained experimental spectra. There are some differences may be due to the interaction forces between molecules and so on. The visualization software displayed the structure characteristics and molecular group vibration of this molecular visually and provided important basis for assigning the vibrational peaks. Rotundine is an important traditional Chinese medicine agent contained in many kinds of sedative drugs. The study provides a strong basis for the rapid, feature and trace identification of Rotundine and also supplies important reference for the biological role of central inhibition of analgesic drugs. PMID:25752044

  15. Hodgkin lymphoma in Tyrol-a population-based study.

    PubMed

    Fong, Dominic; Steurer, Michael; Greil, Richard; Gunsilius, Eberhard; Spizzo, Gilbert; Gastl, Guenther; Tzankov, Alexandar

    2009-05-01

    We aimed to analyze the epidemiology, clinical characteristics, and outcome of patients with Hodgkin lymphoma (HL) diagnosed in Tyrol. All patients with newly diagnosed HL between 1993 and 2005 were included in this study. Among the 158 cases included, nodular lymphocytic predominant HL (nodular paragranuloma) was identified in ten cases (6%) whereas the majority of patients had classical Hodgkin lymphoma. Age (p < 0.01), sex (p = 0.03), risk groups according to the German Hodgkin Study Group stratification (p < 0.01), and bone marrow infiltration (p < 0.01) were of prognostic significance considering overall survival (OS) whereas histological subtype and bulky disease were not. The 5- and 10-year OS rates for the total group were 89% and 85%, respectively. Notably, in patients with advanced-stage HL (n = 49), combined modality treatment resulted in significantly better OS than chemotherapy alone (p = 0.01). Three patients developed a second hematological malignancy and one patient developed breast cancer. However, five patients (3%) had a malignant hematological disorder before occurrence of HL. Concerning treatment-related toxicity, bleomycin-associated lung toxicity was observed in six (4%) patients and five (3%) developed lethal treatment-related infectious complications. Our results provide evidence that the incidence rate of HL in Tyrol is comparable to other Western countries. Modern risk-adapted treatment results in excellent long-term prognosis but may be complicated by serious nonhematological side effects, in particular, infections and bleomycin-induced lung toxicity. Furthermore, 3% of HL patients had an antecedent malignant hematological disease before occurrence of HL.

  16. Miller fisher syndrome: a hospital-based retrospective study.

    PubMed

    Yuan, C L; Wang, Y J; Tsai, C P

    2000-01-01

    Miller Fisher syndrome (MFS), characterized as ataxia, areflexia and ophthalmoplegia, is generally considered as a variant of Guillain-Barré syndrome (GBS). However, some investigators believed that the syndrome could be explained by a central origin. To obtain more information about MFS for comparison with GBS, we conducted a retrospective study by analyzing the clinical data of MFS patients admitted to our hospital over a period of 11 years. The calibrated male/female ratio was 1.65. A seasonal clustering in winter was noted. The percentage of MFS among GBS was especially high (18%, 11/60) in Taiwan when compared with other series. Involvement of limb muscle strength, autonomic function and cranial nerves, except ocular motor nerves, was rarely found in our patients. When MFS is accompanied by limb weakness, it might represent a transitional form between MFS and GBS. Bulbar palsy and dysautonomia might predict a relatively poor prognosis. To obtain more reliable information, lumbar puncture should be done 1 week after disease onset, and electrophysiological tests should be done serially in every MFS patient. Eighty percent (80%, 4/5) of our patients were positive for IgG anti-GQ(1b) antibody activity. In our study, there is more evidence indicating that MFS is a peripheral nervous system disorder; however, no definite conclusion could be made as to whether MFS is exclusively a peripheral or central nervous system disorder. We think MFS is an immune-mediated clinical entity which mainly involves the peripheral nervous system with rare involvement of other parts of the central nervous system. PMID:10965158

  17. Sunlight Exposure and Breast Density: A Population-Based Study

    PubMed Central

    Wu, Sheng-Hui; So, Edwin; Lam, Tsz-ping; Woo, Jean; Yuen, PY; Qin, Ling; Ku, Susanna

    2013-01-01

    Purpose This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabár's mammographic pattern in Chinese women. Methods A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabár's classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders. Results Among 646 participants, women with high breast cancer risk (Tabár's patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabár's pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. <1.32 hr/day). For hours spent in the sun across the ages of 6 to 12 years, the comparable OR was 0.37 (95% CI, 0.15-0.91; p for trend=0.03). Conclusion These findings suggest that higher sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life. PMID:23843849

  18. Low-temperature NMR studies on inosine wobble base pairs.

    PubMed

    Janke, Eline M Basílio; Riechert-Krause, Fanny; Weisz, Klaus

    2011-07-01

    Base pairs formed by the inosine nucleoside (I) play an important role in many physiological processes as well as in various DNA technologies. Relative stabilities and favored base pair geometries of free inosine wobble base pairs in aprotic solvents have been determined through (1)H NMR measurements at room temperature and at very low temperatures in a freonic solvent. As indicated by its significantly deshielded imino proton, the Watson-Crick-type I·C base pair forms a remarkably strong NHN hydrogen bond. For the thermodynamically less stable I·A wobble base pair, two configurations of similar population coexist at 133 K in the slow hydrogen bond exchange regime, namely a Watson-Crick(I)-Watson-Crick(A) geometry and a Watson-Crick(I)-Hoogsteen(A) geometry. I·U base pairs are stabilized by two rather weak hydrogen bonds and are significantly disfavored over inosine self-associates in a low-temperature Freon solution. PMID:21644523

  19. An azo-based PNA monomer: synthesis and spectroscopic study.

    PubMed

    Moustafa, Mohamed E; Hudson, Robert H E

    2011-09-01

    The full synthetic details and photospectroscopic characterization of a peptide nucleic acid (PNA) monomer suitable for Fmoc-based oligomerization chemistry that bears an azobenzene moiety as a base surrogate are reported. The monomer showed the ability to quench the fluorescence emission of fluorescein and pyrene luminophores and proved to be a competent Föster resonance energy transfer partner in a PNA-based molecular beacon.

  20. Organic acids and bases: Review of toxicological studies

    SciTech Connect

    Leung, H.W.; Paustenbach, D.J. )

    1990-01-01

    Organic acids and bases are among the most frequently used chemicals in the manufacturing industries. However, the toxicology of only a number of them has been fully characterized, and for fewer still have occupational exposure limits been established. This paper reviews the acute and chronic toxicity data of the organic acids and bases, and considers the mechanism by which these chemicals produce their effects. A methodology for establishing preliminary occupational exposure limits based on the physicochemical properties of these chemicals is presented. Workplace exposure limits for 20 organic acids and bases which currently have no exposure guidelines are suggested. Advice regarding appropriate medical treatment of exposure to these materials is discussed. 98 references.

  1. Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

    ERIC Educational Resources Information Center

    West, Donna M.; Sterling, Donna R.

    2001-01-01

    Laboratory activities for chemistry students focus attention on the use of acid-base chemistry to examine environmental conditions. After using standard laboratory procedures to analyze soil and rainwater samples, students use web-based resources to interpret their findings. Uses CBL probes and graphing calculators to gather and analyze data and…

  2. Exposure to indoor tanning in France: a population based study

    PubMed Central

    2013-01-01

    Background Tanning lamp sessions have increased in Europe in recent years. Recent epidemiological studies have confirmed a proven link between melanoma and artificial UV exposure. However, in France, little information is available to determine the exposure of the population. This article presents the results from the ‘Baromètre cancer 2010’ concerning the proportion of users exposed to artificial UV radiation in France, their characteristics and level of information on the risks associated. Methods A two stage random sampling telephone survey assisted by CATI system (household, individual) was performed from 3 April 2010 to 7 August 2010 on a sample of 3,359 people aged 15 to 75 years old. Results In 2010, 13.4% of the French population reported to have tanning lamp sessions at least once in their lifetime and 3.5% of the total population reported the use of artificial UV radiation over the last twelve months. Exposure over the last twelve months is most commonly seen among females (5.0%) and young population between 20–25 years old (9.6%). In addition, 3.5% of those under 18 years report having attended UV booths at least once during their lifetime even though they are forbidden to minors. Moreover, more than one the third of users reported more than 10 exposures within a year. The places of exposure cited most often were beauty salons (50%) and tanning centers (46%). Only 49.2% of those surveyed felt that they were well informed on the risks of cancer associated with UV booths. Furthermore, the population was found to have misconceptions about artificial UV radiation. One quarter of the population, believe that artificial UV radiation use before vacation protects the skin from sunburn. Conclusions This first study on artificial UV radiation exposure in France has better quantified and characterized the users. It has also defined the state of knowledge and the perception of risk by the general French population. This work will contribute to determine

  3. Defining habitat covariates in camera-trap based occupancy studies.

    PubMed

    Niedballa, Jürgen; Sollmann, Rahel; bin Mohamed, Azlan; Bender, Johannes; Wilting, Andreas

    2015-01-01

    In species-habitat association studies, both the type and spatial scale of habitat covariates need to match the ecology of the focal species. We assessed the potential of high-resolution satellite imagery for generating habitat covariates using camera-trapping data from Sabah, Malaysian Borneo, within an occupancy framework. We tested the predictive power of covariates generated from satellite imagery at different resolutions and extents (focal patch sizes, 10-500 m around sample points) on estimates of occupancy patterns of six small to medium sized mammal species/species groups. High-resolution land cover information had considerably more model support for small, patchily distributed habitat features, whereas it had no advantage for large, homogeneous habitat features. A comparison of different focal patch sizes including remote sensing data and an in-situ measure showed that patches with a 50-m radius had most support for the target species. Thus, high-resolution satellite imagery proved to be particularly useful in heterogeneous landscapes, and can be used as a surrogate for certain in-situ measures, reducing field effort in logistically challenging environments. Additionally, remote sensed data provide more flexibility in defining appropriate spatial scales, which we show to impact estimates of wildlife-habitat associations.

  4. XAS study of TiO2-based nanomaterials

    NASA Astrophysics Data System (ADS)

    Schneider, K.; Zajac, D.; Sikora, M.; Kapusta, Cz.; Michalow-Mauke, K.; Graule, Th.; Rekas, M.

    2015-07-01

    X-Ray Absorption Spectroscopy studies of the W (0-1 at% W) and Mo-doped TiO2 (0-1 at% Mo) nanoparticle specimens at the K edges of titanium and molybdenum as well as at the L2 L3 edges of tungsten are presented. The materials were prepared with Flame Spray Synthesis process by oxidation of metal-organic precursors. The Ti:K edge spectra in the XANES range show pre-edge and post-edge features characteristic for anatase. A decrease of the amplitude of the EXAFS function with doping is observed and attributed to a softening of the crystal lattice. The Mo EXAFS functions show a considerable decrease of the second-neighbour-shell peak with increasing Mo content, which is attributed to an increased number of cation vacancies. For tungsten a less pronounced effect is observed. The Mo and W XANES spectra do not show noticeable changes with doping level, which indicates their unchanged oxidation states.

  5. Distally Based Iliotibial Band Flap: Anatomic Study with Surgical Considerations.

    PubMed

    Wong, Victor W; Higgins, James P

    2016-09-01

    Background Reconstruction of high-risk fascia, tendon, or ligament defects may benefit from vascularized tissue. The iliotibial band (ITB), a thick fibrous tract of connective tissue, serves as a potential donor site for free tissue transfer but its blood supply has not been thoroughly investigated. The aim of this anatomical study was to investigate the vascular supply to the distal ITB and its role as a free fascial flap. Methods We dissected 16 fresh-frozen cadaveric legs and injected latex into the superolateral geniculate artery (SLGA). A distal ITB fascial flap was designed and measurements were taken for flap dimensions, pedicle length and size, and SLGA perfusion territory. Results The SLGA perfused 11.5 ± 2.3 cm of distal ITB (proximal to the lateral femoral epicondyle) and provided 6.4 ± 0.7cm of pedicle length to the ITB flap. Conclusions Chimeric options to include bone (from the lateral femoral condyle), cartilage (from the lateral femoral trochlea), muscle (from vastus lateralis or biceps femoris), and skin are possible. Surgical harvest techniques are proposed, including preservation of ITB insertions to minimize lateral knee instability. Clinical validation is needed to determine the role of the distal ITB free fascial flap in reconstructive microsurgery.

  6. Integrated Genome-Based Studies of Shewanella Ecophysiology

    SciTech Connect

    Spormann, Alfred

    2011-07-12

    We have constructed in-frame deletions of 7 of the 10 PAS-GGDEF-EAL proteins in Shewanella oneidensis MR-1. We are currently in the process of characterizing the deletion mutants under a wide range of growth conditions. In addition to characterizing growth, we will also examine the biofilm formation of the deletion mutants. In addition to the genetic analyses of the mutants, we are also interested in comparing the activities of the various PAS-GGDEF-EAL proteins. Proteins containing PAS, GGDEF and EAL amino acid sequence motifs may play an important role in regulating c-di-GMP signaling in response to environmental conditions. A genetic and biochemical analysis into the roles of these proteins is underway. PDE activity was observed for several PAS-GGDEF-EAL proteins. One of these proteins, SO0427, also demonstrates possible DGC activity in vitro. Currently, we are studying the growth, motility and biofilm formation characteristics of deletion mutants, as well as the activity of the purified proteins.

  7. Defining habitat covariates in camera-trap based occupancy studies

    PubMed Central

    Niedballa, Jürgen; Sollmann, Rahel; Mohamed, Azlan bin; Bender, Johannes; Wilting, Andreas

    2015-01-01

    In species-habitat association studies, both the type and spatial scale of habitat covariates need to match the ecology of the focal species. We assessed the potential of high-resolution satellite imagery for generating habitat covariates using camera-trapping data from Sabah, Malaysian Borneo, within an occupancy framework. We tested the predictive power of covariates generated from satellite imagery at different resolutions and extents (focal patch sizes, 10–500 m around sample points) on estimates of occupancy patterns of six small to medium sized mammal species/species groups. High-resolution land cover information had considerably more model support for small, patchily distributed habitat features, whereas it had no advantage for large, homogeneous habitat features. A comparison of different focal patch sizes including remote sensing data and an in-situ measure showed that patches with a 50-m radius had most support for the target species. Thus, high-resolution satellite imagery proved to be particularly useful in heterogeneous landscapes, and can be used as a surrogate for certain in-situ measures, reducing field effort in logistically challenging environments. Additionally, remote sensed data provide more flexibility in defining appropriate spatial scales, which we show to impact estimates of wildlife-habitat associations. PMID:26596779

  8. Health Literacy in Taiwan: A Population-Based Study.

    PubMed

    Duong, Van Tuyen; Lin, I-Feng; Sorensen, Kristine; Pelikan, Jürgen M; Van Den Broucke, Stephan; Lin, Ying-Chin; Chang, Peter Wushou

    2015-11-01

    Data on health literacy (HL) in the population is limited for Asian countries. This study aimed to test the validity of the Mandarin version of the European Health Literacy Survey Questionnaire (HLS-EU-Q) for use in the general public in Taiwan. Multistage stratification random sampling resulted in a sample of 2989 people aged 15 years and above. The HLS-EU-Q was validated by confirmatory factor analysis with excellent model data fit indices. The general HL of the Taiwanese population was 34.4 ± 6.6 on a scale of 50. Multivariate regression analysis showed that higher general HL is significantly associated with the higher ability to pay for medication, higher self-perceived social status, higher frequency of watching health-related TV, and community involvement but associated with younger age. HL is also associated with health status, health behaviors, and health care accessibility and use. The HLS-EU-Q was found to be a useful tool to assess HL and its associated factors in the general population. PMID:26419635

  9. Space-based hyperspectral imaging spectroradiometer for coastal studies

    NASA Astrophysics Data System (ADS)

    Puschell, Jeffery J.; Silny, John; Cook, Lacy; Champion, Shaun; Schiller, Stephen; La Komski, David; Nastal, Jamie; Malone, Neil; Davis, Curtiss

    2011-11-01

    Resolving the complexity of coastal and estuarine waters requires high spatial resolution, hyperspectral imaging spectroradiometry. Hyperspectral measurements also provide capability for measuring bathymetry and bottom types in optically shallow water and for detailed cross calibration with other instruments in polar and geosynchronous orbit. This paper reports on recent design studies for a hyperspectral Coastal Imager (CI - pronounced "sea") that measures key data products from sun synchronous orbit. These products include water-leaving radiances in the near-ultraviolet, visible and near-infrared for separation of absorbing and scattering coastal water constituents and for calculation of chlorophyll fluorescence. In addition, CI measures spectral radiances in the near-infrared and shortwave infrared for atmospheric corrections while also measuring cloud radiances without saturation to enable more accurate removal of instrument stray light effects. CI provides contiguous spectral coverage from 380 to 2500 nm at 20 m GIFOV at nadir across 5000+ km2 scenes with spectral sampling, radiometric sensitivity and calibration performance needed to meet the demanding requirements of coastal imaging. This paper describes the CI design, including concepts of operation for data collection, calibration (radiometric, spectral and spatial), onboard processing and data transmission to Earth. Performance characteristics for the instrument and all major subsystems including the optics, focal plane assemblies, onboard calibration, onboard processing and thermal subsystem are presented along with performance predictions for instrument sensitivity and calibration. Initial estimates of size, mass, power and data rate are presented.

  10. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    SciTech Connect

    Nagendra, K.; Babu, G. Satish; Gowda, Veeranna; Reddy, C. Narayana

    2011-07-15

    Glasses in the system xLi{sub 2}SO{sub 4}-20Li{sub 2}O-(80-x) [80P{sub 2}O{sub 5}-20V{sub 2}O{sub 5}](5{>=}x{>=}20 mol%) has been prepared by melt quenching method. Dc and ac conductivity has been studied over a wide range of frequency (10 Hz to 10 MHz) and temperature (298 K-523 K). The dc conductivity found to increase with increase of Li{sub 2}SO{sub 4} concentration. The ac conductivities have been fitted to the Almond-West type single power law equation {sigma}({omega}) = {sigma}(0)+A{omega}{sup s} where 's' is the power law exponent. The ac conductivity found to increase with increase of Li{sub 2}SO{sub 4} concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

  11. Infrared thermography based studies on mobile phone induced heating

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Bagavathiappan, S.; Soumya, C.; Jayakumar, T.; Philip, John

    2015-07-01

    Here, we report the skin temperature rise due to the absorption of radio frequency (RF) energy from three handheld mobile phones using infrared thermography technique. Experiments are performed under two different conditions, viz. when the mobile phones are placed in soft touch with the skin surface and away from the skin surface. Additionally, the temperature rise of mobile phones during charging, operation and simultaneous charging and talking are monitored under different exposure conditions. It is observed that the temperature of the cheek and ear regions monotonically increased with time during the usage of mobile phones and the magnitude of the temperature rise is higher for the mobile phone with higher specific absorption rate. The increase in skin temperature is higher when the mobile phones are in contact with the skin surface due to the combined effect of absorption of RF electromagnetic power and conductive heat transfer. The increase in the skin temperature in non-contact mode is found to be within the safety limit of 1 °C. The measured temperature rise is in good agreement with theoretical predictions. The empirical equation obtained from the temperature rise on the cheek region of the subjects correlates well with the specific absorption rate of the mobile phones. Our study suggests that the use of mobile phones in non-contact mode can significantly lower the skin temperature rise during its use and hence, is safer compared to the contact mode.

  12. Shock Loading Studies of AP/AL/HTPB Based Propellants

    NASA Astrophysics Data System (ADS)

    Boteler, J. M.; Lindfors, A. J.

    1995-08-01

    The unreacted Hugoniots of three class 1.3 propellants have been investigated by shock compression experiments. Shock waves were generated by planar impact in a 75 mm single stage powder gun. Manganin and PVDF pressure gauges provided pressure-time histories to 200 kbar. The propellants were of similar formulation differing only in coarse AP particle size and the addition of a bum rate modifier (Fe2O3). All propellants contained 90% solids by weight and HTPB as binder. Results show negligible effect of AP particle size on shock response in contrast to the addition of Fe2O3 which appears to "stiffen" the host material. Within experimental error, the unreacted Hugoniots compare favorably to the solid AP Hugoniot. Five shock experiments were performed on propellant samples strained to induce in situ voids. The material state was quantified by uniaxial tension dilatometry. Experimental records suggest chemical reactivity behind the shock front. These results are discussed and compared to experimental studies reported previously.

  13. Shock Loading Studies of AP/AL/HTPB Based Propellants

    NASA Astrophysics Data System (ADS)

    Boteler, J. M.; Lindfors, A. J.

    1996-05-01

    The unreacted Hugoniots of three class 1.3 propellants have been investigated by shock compression experiments. Shock waves were generated by planar impact in a 75 mm single stage powder gun. Manganin and PVDF pressure gauges provided pressure-time histories to 200 kbar. The propellants were of similar formulation differing only in coarse AP particle size and the addition of a bum rate modifier ( Fe 2 O 3 ). All propellants contained 90% solids by weight and HTPB as binder. Results show negligible effect of AP particle size on shock response in contrast to the addition of Fe 2 O 3 which appears to "stiffen" the host material. Within experimental error, the unreacted Hugoniots compare favorably to the solid AP Hugoniot. Five shock experiments were performed on propellant samples strained to induce in situ voids. The material state was quantified by uniaxial tension dilatometry. Experimental records suggest chemical reactivity behind the shock front. These results are discussed and compared to experimental studies reported previously.

  14. A global benchmark study using affinity-based biosensors.

    PubMed

    Rich, Rebecca L; Papalia, Giuseppe A; Flynn, Peter J; Furneisen, Jamie; Quinn, John; Klein, Joshua S; Katsamba, Phini S; Waddell, M Brent; Scott, Michael; Thompson, Joshua; Berlier, Judie; Corry, Schuyler; Baltzinger, Mireille; Zeder-Lutz, Gabrielle; Schoenemann, Andreas; Clabbers, Anca; Wieckowski, Sebastien; Murphy, Mary M; Page, Phillip; Ryan, Thomas E; Duffner, Jay; Ganguly, Tanmoy; Corbin, John; Gautam, Satyen; Anderluh, Gregor; Bavdek, Andrej; Reichmann, Dana; Yadav, Satya P; Hommema, Eric; Pol, Ewa; Drake, Andrew; Klakamp, Scott; Chapman, Trevor; Kernaghan, Dawn; Miller, Ken; Schuman, Jason; Lindquist, Kevin; Herlihy, Kara; Murphy, Michael B; Bohnsack, Richard; Andrien, Bruce; Brandani, Pietro; Terwey, Danny; Millican, Rohn; Darling, Ryan J; Wang, Liann; Carter, Quincy; Dotzlaf, Joe; Lopez-Sagaseta, Jacinto; Campbell, Islay; Torreri, Paola; Hoos, Sylviane; England, Patrick; Liu, Yang; Abdiche, Yasmina; Malashock, Daniel; Pinkerton, Alanna; Wong, Melanie; Lafer, Eileen; Hinck, Cynthia; Thompson, Kevin; Primo, Carmelo Di; Joyce, Alison; Brooks, Jonathan; Torta, Federico; Bagge Hagel, Anne Birgitte; Krarup, Janus; Pass, Jesper; Ferreira, Monica; Shikov, Sergei; Mikolajczyk, Malgorzata; Abe, Yuki; Barbato, Gaetano; Giannetti, Anthony M; Krishnamoorthy, Ganeshram; Beusink, Bianca; Satpaev, Daulet; Tsang, Tiffany; Fang, Eric; Partridge, James; Brohawn, Stephen; Horn, James; Pritsch, Otto; Obal, Gonzalo; Nilapwar, Sanjay; Busby, Ben; Gutierrez-Sanchez, Gerardo; Gupta, Ruchira Das; Canepa, Sylvie; Witte, Krista; Nikolovska-Coleska, Zaneta; Cho, Yun Hee; D'Agata, Roberta; Schlick, Kristian; Calvert, Rosy; Munoz, Eva M; Hernaiz, Maria Jose; Bravman, Tsafir; Dines, Monica; Yang, Min-Hsiang; Puskas, Agnes; Boni, Erica; Li, Jiejin; Wear, Martin; Grinberg, Asya; Baardsnes, Jason; Dolezal, Olan; Gainey, Melicia; Anderson, Henrik; Peng, Jinlin; Lewis, Mark; Spies, Peter; Trinh, Quyhn; Bibikov, Sergei; Raymond, Jill; Yousef, Mohammed; Chandrasekaran, Vidya; Feng, Yuguo; Emerick, Anne; Mundodo, Suparna; Guimaraes, Rejane; McGirr, Katy; Li, Yue-Ji; Hughes, Heather; Mantz, Hubert; Skrabana, Rostislav; Witmer, Mark; Ballard, Joshua; Martin, Loic; Skladal, Petr; Korza, George; Laird-Offringa, Ite; Lee, Charlene S; Khadir, Abdelkrim; Podlaski, Frank; Neuner, Phillippe; Rothacker, Julie; Rafique, Ashique; Dankbar, Nico; Kainz, Peter; Gedig, Erk; Vuyisich, Momchilo; Boozer, Christina; Ly, Nguyen; Toews, Mark; Uren, Aykut; Kalyuzhniy, Oleksandr; Lewis, Kenneth; Chomey, Eugene; Pak, Brian J; Myszka, David G

    2009-03-15

    To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users of different expertise levels. The two proteins (a 50-kDa Fab and a 60-kDa glutathione S-transferase [GST] antigen) form a relatively high-affinity complex, so participants needed to optimize several experimental parameters, including ligand immobilization and regeneration conditions as well as analyte concentrations and injection/dissociation times. Although most participants collected binding responses that could be fit to yield kinetic parameters, the quality of a few data sets could have been improved by optimizing the assay design. Once these outliers were removed, the average reported affinity across the remaining panel of participants was 620 pM with a standard deviation of 980 pM. These results demonstrate that when this biosensor assay was designed and executed appropriately, the reported rate constants were consistent, and independent of which protein was immobilized and which biosensor was used.

  15. Distally Based Iliotibial Band Flap: Anatomic Study with Surgical Considerations.

    PubMed

    Wong, Victor W; Higgins, James P

    2016-09-01

    Background Reconstruction of high-risk fascia, tendon, or ligament defects may benefit from vascularized tissue. The iliotibial band (ITB), a thick fibrous tract of connective tissue, serves as a potential donor site for free tissue transfer but its blood supply has not been thoroughly investigated. The aim of this anatomical study was to investigate the vascular supply to the distal ITB and its role as a free fascial flap. Methods We dissected 16 fresh-frozen cadaveric legs and injected latex into the superolateral geniculate artery (SLGA). A distal ITB fascial flap was designed and measurements were taken for flap dimensions, pedicle length and size, and SLGA perfusion territory. Results The SLGA perfused 11.5 ± 2.3 cm of distal ITB (proximal to the lateral femoral epicondyle) and provided 6.4 ± 0.7cm of pedicle length to the ITB flap. Conclusions Chimeric options to include bone (from the lateral femoral condyle), cartilage (from the lateral femoral trochlea), muscle (from vastus lateralis or biceps femoris), and skin are possible. Surgical harvest techniques are proposed, including preservation of ITB insertions to minimize lateral knee instability. Clinical validation is needed to determine the role of the distal ITB free fascial flap in reconstructive microsurgery. PMID:27135145

  16. Study of a nTHGEM-based thermal neutron detector

    NASA Astrophysics Data System (ADS)

    Li, Ke; Zhou, Jian-Rong; Wang, Xiao-Dong; Xiong, Tao; Zhang, Ying; Xie, Yu-Guang; Zhou, Liang; Xu, Hong; Yang, Gui-An; Wang, Yan-Feng; Wang, Yan; Wu, Jin-Jie; Sun, Zhi-Jia; Hu, Bi-Tao

    2016-07-01

    With new generation neutron sources, traditional neutron detectors cannot satisfy the demands of the applications, especially under high flux. Furthermore, facing the global crisis in 3He gas supply, research on new types of neutron detector as an alternative to 3He is a research hotspot in the field of particle detection. GEM (Gaseous Electron Multiplier) neutron detectors have high counting rate, good spatial and time resolution, and could be one future direction of the development of neutron detectors. In this paper, the physical process of neutron detection is simulated with Geant4 code, studying the relations between thermal conversion efficiency, boron thickness and number of boron layers. Due to the special characteristics of neutron detection, we have developed a novel type of special ceramic nTHGEM (neutron THick GEM) for neutron detection. The performance of the nTHGEM working in different Ar/CO2 mixtures is presented, including measurements of the gain and the count rate plateau using a copper target X-ray source. A detector with a single nTHGEM has been tested for 2-D imaging using a 252Cf neutron source. The key parameters of the performance of the nTHGEM detector have been obtained, providing necessary experimental data as a reference for further research on this detector. Supported by National Natural Science Foundation of China (11127508, 11175199, 11205253, 11405191), Key Laboratory of Neutron Physics, CAEP (2013DB06, 2013BB04) and CAS (YZ201512)

  17. Mechanical Ventilation Boot Camp: A Simulation-Based Pilot Study

    PubMed Central

    Yee, Jennifer; Fuenning, Charles; George, Richard; Hejal, Rana; Haines, Nhi; Dunn, Diane; Gothard, M. David; Ahmed, Rami A.

    2016-01-01

    Objectives. Management of mechanically ventilated patients may pose a challenge to novice residents, many of which may not have received formal dedicated critical care instruction prior to starting their residency training. There is a paucity of data regarding simulation and mechanical ventilation training in the medical education literature. The purpose of this study was to develop a curriculum to educate first-year residents on addressing and troubleshooting ventilator alarms. Methods. Prospective evaluation was conducted of seventeen residents undergoing a twelve-hour three-day curriculum. Residents were assessed using a predetermined critical action checklist for each case, as well as pre- and postcurriculum multiple-choice cognitive knowledge questionnaires and confidence surveys. Results. Significant improvements in cognitive knowledge, critical actions, and self-reported confidence were demonstrated. The mean change in test score from before to after intervention was +26.8%, and a median score increase of 25% was noted. The ARDS and the mucus plugging cases had statistically significant improvements in critical actions, p < 0.001. A mean increase in self-reported confidence was realized (1.55 to 3.64), p = 0.049. Conclusions. A three-day simulation curriculum for residents was effective in increasing competency, knowledge, and confidence with ventilator management. PMID:26949545

  18. Studies of microstructural imperfections of powdered Zirconium-based alloys

    SciTech Connect

    Chowdhury, P.S.; Mukherjee, P.

    2010-11-15

    Different model based approaches of X-ray diffraction line profile analysis have been applied on the heavily deformed zirconium-based alloys in the powdered form to characterize the microstructural parameters like domain size, microstrain and dislocation density. In characterizing the microstructure of the material, these methods are complimentary to each other. Though the parameters obtained by different techniques are differently defined and thus not necessarily comparable, the values of domain size and microstrain obtained from the different techniques show similar trends.

  19. A study testing the usefulness of a dish-based food-frequency questionnaire developed for epidemiological studies in Korea.

    PubMed

    Kim, Young Ok; Kim, Mi Kyung; Lee, Sang-Ah; Yoon, Young Mi; Sasaki, Satoshi

    2009-04-01

    The purpose of the present study was to test the usefulness of dish items selected in developing a dish-based FFQ (DFFQ) to be used for epidemiological studies in Korea. The dietary data of 6817 subjects from the 2001 Korean National Health and Nutrition Examination Survey were used for the analysis. The 24 h recall method was employed for the dietary survey. Initially, ninety-five dish items were selected in developing the DFFQ based on consumption frequency, contribution of selected nutrients and coverage of between-person variations. The usefulness of the selected ninety-five dish items was tested based on their degree of contribution in supplying nutrients in the cumulative percentage contribution (cPC), as well as on their degree of explanation for between-person variation in the cumulative regression coefficient (cMRC). According to the results, the ninety-five selected dish items accounted for an average of 92.3 % of seventeen nutrients consumed by the study subjects based on cPC estimation. The top twenty items among the ninety-five dish items covered 70 to 91 % of the between-person variation for the seventeen nutrients based on cMRC estimation. Thus, the results suggest that the ninety-five items would be useful in developing a FFQ for use in epidemiological studies of Koreans, within less than 10 % underestimation. PMID:18786277

  20. Study on automatic testing network based on LXI

    NASA Astrophysics Data System (ADS)

    Hu, Qin; Xu, Xing

    2006-11-01

    LXI (LAN eXtensions for Instrumentation), which is an extension of the widely used Ethernet technology in the automatic testing field, is the next generation instrumental platform. LXI standard is based on the industry standard Ethernet technolog, using the standard PC interface as the primary communication bus between devices. It implements the IEEE802.3 standard and supports TCP/IP protocol. LXI takes the advantage of the ease of use of GPIB-based instruments, the high performance and compact size of VXI/PXI instruments, and the flexibility and high throughput of Ethernet all at the same time. The paper firstly introduces the specification of LXI standard. Then, an automatic testing network architecture which is based on LXI platform is proposed. The automatic testing network is composed of several sets of LXI-based instruments, which are connected via an Ethernet switch or router. The network is computer-centric, and all the LXI-based instruments in the network are configured and initialized in computer. The computer controls the data acquisition, and displays the data on the screen. The instruments are using Ethernet connection as I/O interface, and can be triggered over a wired trigger interface, over LAN or over IEEE 1588 Precision Time Protocol running over the LAN interface. A hybrid automatic testing network comprised of LXI compliant devices and legacy instruments including LAN instruments as well as GPIB, VXI and PXI products connected via internal or external adaptors is also discussed at the end of the paper.

  1. FTIR studies of PVC/PMMA blend based polymer electrolytes.

    PubMed

    Ramesh, S; Leen, Koay Hang; Kumutha, K; Arof, A K

    2007-04-01

    The polymer electrolytes composing of the blend of polyvinyl chloride-polymethyl methacrylate (PVC/PMMA) with lithium triflate (LiCF3SO3) as salt, ethylene carbonate (EC) and dibutyl phthalate (DBP) as plasticizers and silica (SiO2) as the composite filler were prepared. FTIR studies confirm the complexation between PVC/PMMA blends. The CCl stretching mode at 834 cm-1 for pure PVC is shifted to 847 cm-1 in PVC-PMMA-LiCF3SO3 system. This suggests that there is interaction between Cl in PVC with Li+ ion from LiCF3SO3. The band due to OCH3 at 1150 cm-1 for PVC-PMMA blend is shifted to 1168 cm-1 in PVC-PMMA-LiCF3SO3 system. This shift is expected to be due to the interaction between Li+ ion and the oxygen atom in PMMA. The symmetric vibration band and the asymmetric vibration band of LiCF3SO3 at 1033 and 1256 cm-1 shifted to 1075 and 1286 cm-1 in the DBP-EC plasticized PVC-PMMA-LiCF3SO3 complexes. The interaction between Li+ ions and SiO2 will lead to an increase in the number of free plasticizers (which does not interact with Li+ ions). When the silica content increases from 2% to 5%, the intensity of the peak at 896 cm-1 (due to the ring breathing vibration of free EC) increases in PVC-PMMA-LiCF3SO3-DBP-EC system.

  2. Reasoning Based Quality Assurance of Medical Ontologies: A Case Study

    PubMed Central

    Horridge, Matthew; Parsia, Bijan; Noy, Natalya F.; Musenm, Mark A.

    2014-01-01

    The World Health Organisation is using OWL as a key technology to develop ICD-11 – the next version of the well-known International Classification of Diseases. Besides providing better opportunities for data integration and linkages to other well-known ontologies such as SNOMED-CT, one of the main promises of using OWL is that it will enable various forms of automated error checking. In this paper we investigate how automated OWL reasoning, along with a Justification Finding Service can be used as a Quality Assurance technique for the development of large and complex ontologies such as ICD-11. Using the International Classification of Traditional Medicine (ICTM) – Chapter 24 of ICD-11 – as a case study, and an expert panel of knowledge engineers, we reveal the kinds of problems that can occur, how they can be detected, and how they can be fixed. Specifically, we found that a logically inconsistent version of the ICTM ontology could be repaired using justifications (minimal entailing subsets of an ontology). Although over 600 justifications for the inconsistency were initially computed, we found that there were three main manageable patterns or categories of justifications involving TBox and ABox axioms. These categories represented meaningful domain errors to an expert panel of ICTM project knowledge engineers, who were able to use them to successfully determine the axioms that needed to be revised in order to fix the problem. All members of the expert panel agreed that the approach was useful for debugging and ensuring the quality of ICTM. PMID:25954373

  3. Permanent sequelae in sports injuries: a population based study

    PubMed Central

    Marchi, A.; Di, B; Messi, G.; Gazzola, G.

    1999-01-01

    AIM—To identify permanent sequelae after sports injuries in children and adolescents.
METHODS—In 1985, a prospective register was drawn up of all sports related injuries reported that year by the residents of Trieste, Italy aged 6-15 years. Moderate to severe injuries (scoring ⩾ 2 on the abbreviated injury scale (AIS)) were the object of a longitudinal clinical study. In 1988, 30.9% of the 220 subjects enrolled had sequelae. A further follow up was undertaken in 1997.
RESULTS—The follow up in 1997 involved 54 subjects (26 girls; average age 24.5 years). Subjective and objective sequelae, by now considered to be permanent, were found in 61.1%, corresponding to 15% of the AIS ⩾ 2 injuries recorded in 1985. The prevalence of sequelae was similar in the two sexes, in relation to the child's age at time of injury, and in the different sports practised. It was higher in relation to the severity of the lesion (89% of AIS 3injuries examined, 56% of AIS 2 injuries) and to the type of lesion and its location. With regard to AIS ⩾ 2 injuries, permanent sequelae were found in 50% of ankle fractures, 43% of elbow fractures, 33% of leg/foot fractures, 25% of knee sprains, and 23% of ankle sprains.
CONCLUSIONS—The frequency of sequelae in sports injuries in children and adolescents is high. The risk appears to be connected to certain anatomical and functional age characteristics. Prevention strategies should include specific assessment of physical fitness and adequate follow up after the accident, particularly rehabilitation.

 PMID:10490437

  4. Performability modeling based on real data: A case study

    NASA Technical Reports Server (NTRS)

    Hsueh, M. C.; Iyer, R. K.; Trivedi, K. S.

    1988-01-01

    Described is a measurement-based performability model based on error and resource usage data collected on a multiprocessor system. A method for identifying the model structure is introduced and the resulting model is validated against real data. Model development from the collection of raw data to the estimation of the expected reward is described. Both normal and error behavior of the system are characterized. The measured data show that the holding times in key operational and error states are not simple exponentials and that a semi-Markov process is necessary to model system behavior. A reward function, based on the service rate and the error rate in each state, is then defined in order to estimate the performability of the system and to depict the cost of apparent types of errors.

  5. A computational study of nodal-based tetrahedral element behavior.

    SciTech Connect

    Gullerud, Arne S.

    2010-09-01

    This report explores the behavior of nodal-based tetrahedral elements on six sample problems, and compares their solution to that of a corresponding hexahedral mesh. The problems demonstrate that while certain aspects of the solution field for the nodal-based tetrahedrons provide good quality results, the pressure field tends to be of poor quality. Results appear to be strongly affected by the connectivity of the tetrahedral elements. Simulations that rely on the pressure field, such as those which use material models that are dependent on the pressure (e.g. equation-of-state models), can generate erroneous results. Remeshing can also be strongly affected by these issues. The nodal-based test elements as they currently stand need to be used with caution to ensure that their numerical deficiencies do not adversely affect critical values of interest.

  6. Space-based solar power conversion and delivery systems study. Volume 4: Energy conversion systems studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Solar cells and optical configurations for the SSPS were examined. In this task, three specific solar cell materials were examined: single crystal silicon, single crystal gallium arsenide, and polycrystalline cadmium sulfide. The comparison of the three different cells on the basis of a subsystem parametric cost per kW of SSPS-generated power at the terrestrial utility interface showed that gallium arsenide was the most promising solar cell material at high concentration ratios. The most promising solar cell material with no concentration, was dependent upon the particular combination of parameters representing cost, mass and performance that were chosen to represent each cell in this deterministic comparative analysis. The potential for mass production, based on the projections of the present state-of-the-art would tend to favor cadmium sulfide in lieu of single crystal silicon or gallium arsenide solar cells.

  7. In Vivo RNAi-Based Screens: Studies in Model Organisms

    PubMed Central

    Yamamoto-Hino, Miki; Goto, Satoshi

    2013-01-01

    RNA interference (RNAi) is a technique widely used for gene silencing in organisms and cultured cells, and depends on sequence homology between double-stranded RNA (dsRNA) and target mRNA molecules. Numerous cell-based genome-wide screens have successfully identified novel genes involved in various biological processes, including signal transduction, cell viability/death, and cell morphology. However, cell-based screens cannot address cellular processes such as development, behavior, and immunity. Drosophila and Caenorhabditis elegans are two model organisms whose whole bodies and individual body parts have been subjected to RNAi-based genome-wide screening. Moreover, Drosophila RNAi allows the manipulation of gene function in a spatiotemporal manner when it is implemented using the Gal4/UAS system. Using this inducible RNAi technique, various large-scale screens have been performed in Drosophila, demonstrating that the method is straightforward and valuable. However, accumulated results reveal that the results of RNAi-based screens have relatively high levels of error, such as false positives and negatives. Here, we review in vivo RNAi screens in Drosophila and the methods that could be used to remove ambiguity from screening results. PMID:24705267

  8. Lunar surface base propulsion system study, volume 1

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The efficiency, capability, and evolution of a lunar base will be largely dependent on the transportation system that supports it. Beyond Space Station in low Earth orbit (LEO), a Lunar-derived propellant supply could provide the most important resource for the transportation infrastructure. The key to an efficient Lunar base propulsion system is the degree of Lunar self-sufficiency (from Earth supply) and reasonable propulsion system performance. Lunar surface propellant production requirements must be accounted in the measurement of efficiency of the entire space transportation system. Of all chemical propellant/propulsion systems considered, hydrogen/oxygen (H/O) OTVs appear most desirable, while both H/O and aluminum/oxygen propulsion systems may be considered for the lander. Aluminized-hydrogen/oxygen and Silane/oxygen propulsion systems are also promising candidates. Lunar propellant availability and processing techniques, chemical propulsion/vehicle design characteristics, and the associated performance of the total transportation infrastructure are reviewed, conceptual propulsion system designs and vehicle/basing concepts, and technology requirements are assessed in context of a Lunar Base mission scenario.

  9. Implementing Outcomes Based Accountability in Children's Services. Case Studies

    ERIC Educational Resources Information Center

    Bergeron, Caroline; Chamberlain, Tamsin; George, Nalia; Golden, Sarah; Mundy, Ellie; Southcott, Clare; Walker, Fiona

    2010-01-01

    Outcomes Based Accountability (OBA) is an approach that Children's Trusts and Children's Services can use to assist with planning services and assessing their performance. The OBA approach focuses on outcomes that are desired and monitoring and evidencing progress towards those desired outcomes. OBA makes a distinction between two types of…

  10. Advances in reprogramming-based study of neurologic disorders.

    PubMed

    Nityanandam, Anjana; Baldwin, Kristin K

    2015-06-01

    The technology to convert adult human non-neural cells into neural lineages, through induced pluripotent stem cells (iPSCs), somatic cell nuclear transfer, and direct lineage reprogramming or transdifferentiation has progressed tremendously in recent years. Reprogramming-based approaches aimed at manipulating cellular identity have enormous potential for disease modeling, high-throughput drug screening, cell therapy, and personalized medicine. Human iPSC (hiPSC)-based cellular disease models have provided proof of principle evidence of the validity of this system. However, several challenges remain before patient-specific neurons produced by reprogramming can provide reliable insights into disease mechanisms or be efficiently applied to drug discovery and transplantation therapy. This review will first discuss limitations of currently available reprogramming-based methods in faithfully and reproducibly recapitulating disease pathology. Specifically, we will address issues such as culture heterogeneity, interline and inter-individual variability, and limitations of two-dimensional differentiation paradigms. Second, we will assess recent progress and the future prospects of reprogramming-based neurologic disease modeling. This includes three-dimensional disease modeling, advances in reprogramming technology, prescreening of hiPSCs and creating isogenic disease models using gene editing. PMID:25749371

  11. School-Based Budgeting Survey Study of Pilot Schools.

    ERIC Educational Resources Information Center

    Robinson, Carol

    This report describes results of a survey on school-based budgeting (SBB) in the Albuquerque, New Mexico, public schools (APS). SBB began in the 1986-87 school year at 33 of the 116 APS schools and alternative schools, with 16 elementary, 11 middle, and 6 high schools, participating in the first year. A total of 131 responses were received from…

  12. Home-Based Crisis Therapy: A Comparative Outcome Study.

    ERIC Educational Resources Information Center

    Rowland, Charity; And Others

    Substitute care for a child at risk has been been associated with psychological distress in the child and his family and a drain on public finances. To investigate the cost effectiveness and ultimate influence on family intactness of home-based family crisis intervention, 77 low income, inner city families with an adolescent child at risk of…

  13. Advances in Reprogramming-Based Study of Neurologic Disorders

    PubMed Central

    Baldwin, Kristin K.

    2015-01-01

    The technology to convert adult human non-neural cells into neural lineages, through induced pluripotent stem cells (iPSCs), somatic cell nuclear transfer, and direct lineage reprogramming or transdifferentiation has progressed tremendously in recent years. Reprogramming-based approaches aimed at manipulating cellular identity have enormous potential for disease modeling, high-throughput drug screening, cell therapy, and personalized medicine. Human iPSC (hiPSC)-based cellular disease models have provided proof of principle evidence of the validity of this system. However, several challenges remain before patient-specific neurons produced by reprogramming can provide reliable insights into disease mechanisms or be efficiently applied to drug discovery and transplantation therapy. This review will first discuss limitations of currently available reprogramming-based methods in faithfully and reproducibly recapitulating disease pathology. Specifically, we will address issues such as culture heterogeneity, interline and inter-individual variability, and limitations of two-dimensional differentiation paradigms. Second, we will assess recent progress and the future prospects of reprogramming-based neurologic disease modeling. This includes three-dimensional disease modeling, advances in reprogramming technology, prescreening of hiPSCs and creating isogenic disease models using gene editing. PMID:25749371

  14. Knowledge-Based Aid: A Four Agency Comparative Study

    ERIC Educational Resources Information Center

    McGrath, Simon; King, Kenneth

    2004-01-01

    Part of the response of many development cooperation agencies to the challenges of globalisation, ICTs and the knowledge economy is to emphasise the importance of knowledge for development. This paper looks at the discourses and practices of ''knowledge-based aid'' through an exploration of four agencies: the World Bank, DFID, Sida and JICA. It…

  15. Impact of MR based attenuation correction on neurological PET studies

    PubMed Central

    Su, Yi; Rubin, Brian B.; McConathy, Jonathan; Laforest, Richard; Qi, Jing; Sharma, Akash; Priatna, Agus; Benzinger, Tammie L.S.

    2016-01-01

    Hybrid positron emission tomography (PET) and magnetic resonance (MR) scanners have become a reality in recent years with the benefits of reduced radiation exposure, reduction of imaging time, and potential advantages in quantification. Appropriate attenuation correction remains a challenge. Biases in PET activity measurements were demonstrated using the current MR based attenuation correction technique. We aim to investigate the impact of using standard MRAC technique on the clinical and research utility of PET/MR hybrid scanner for amyloid imaging. Methods Florbetapir scans were obtained on 40 participants on a Biograph mMR hybrid scanner with simultaneous MR acquisition. PET images were reconstructed using both MR and CT derived attenuation map. Quantitative analysis was performed for both datasets to assess the impact of MR based attenuation correction to absolute PET activity measurements as well as target to reference ratio (SUVR). Clinical assessment was also performed by a nuclear medicine physician to determine amyloid status based on the criteria in the FDA prescribing information for florbetapir. Results MR based attenuation correction led to underestimation of PET activity for most part of the brain with a small overestimation for deep brain regions. There is also an overestimation of SUVR values with cerebellar reference. SUVR measurements obtained from the two attenuation correction methods were strongly correlated. Clinical assessment of amyloid status resulted in identical classification as positive or negative regardless of the attenuation correction methods. Conclusions MR based attenuation correction cause biases in quantitative measurements. The biases may be accounted for by a linear model, although the spatial variation cannot be easily modelled. The quantitative differences however did not affect clinical assessment as positive or negative. PMID:26823562

  16. Graphene base heterojunction transistor: An explorative study on device potential, optimization, and base parasitics

    NASA Astrophysics Data System (ADS)

    Di Lecce, Valerio; Grassi, Roberto; Gnudi, Antonio; Gnani, Elena; Reggiani, Susanna; Baccarani, Giorgio

    2015-12-01

    The Graphene-Base Heterojunction Transistor (GBHT) is a novel device concept with a high potential for analog high-frequency RF operation, in which the current is due to both thermionic emission and tunneling. In this paper we study through numerical simulations the influence of previously uninvestigated aspects of Si- and Ge-based GBHTs-namely, crystallographic orientation and doping density values-on the device performance; a comparison with an aggressively scaled HBT structure is then reported. The simulations are carried out with an in-house developed code based on a 1-D quantum transport model within the effective mass approximation and the assumptions of ballistic transport with non-parabolic corrections and ideal semiconductor-graphene interface. We show that crystallographic orientation has a negligible effect on the GBHT performance. The doping density values in the GBHT emitter and collector regions can be tailored to maximize the device performance: the Si device shows better overall performance than the Ge one, yielding a peak cut-off frequency fT higher than 4 THz together with an intrinsic voltage gain above 10, or even higher fT at the cost of a lower gain. The Si-based GBHT can potentially outperform the SiGe HBT by a 2.8 higher fT . For a Si-based GBHT with a circular active region of diameter 50-100 nm, a theoretical balanced value for fT and fmax above 2 THz can be achieved, provided the base parasitics are carefully minimized.

  17. Electrical Studies On Hexanoyl Chitosan-based Nanocomposite Polymer Electrolytes

    NASA Astrophysics Data System (ADS)

    Muhammad, F. H.; Subban, R. H. Y.; Wime, Tan

    2009-06-01

    Hexanoyl chitosan-based nanocomposite polymer electrolytes were prepared using solution casting technique. The effect of addition of nanosize titanium oxide, TiO2 as the filler on the electrical properties of the prepared electrolyte system was investigated by impedance spectroscopy. The maximum conductivity of 3.06×10-4 S cm-1 was achieved with addition of 6 wt%. TiO2 which is 1 order of magnitude higher than the filler-free electrolyte sample (σ = 1.83×10-5 S cm-1). The Rice and Roth model was proposed to explain the conductivity variation for the prepared electrolyte system. The ac conductivity of hexanoyl chitosan-based nanocomposite electrolytes was also analyzed.

  18. Study on spectrometer based upon volume holographic transmission grating

    NASA Astrophysics Data System (ADS)

    Huang, Zhen; Liu, Guodong; Ren, Zhong; Zeng, Lvming

    2010-10-01

    In this present paper, a spectrometer based upon axial transmissive optical structure with the volume-phase holographic (VPH) transmission grating technology is introduced. We give a physical insight for the structure and mechanism of photorefractive volume holographic gratings and theoretically analyze some important performance parameters of the spectrometer device using the coupled wave theory, which should be considered in the process of the following design for the device with volume phase holographic transmission gratings. The experimental results show, owing to its axial transmissive optical geometry and the perfect performance of the VPH transmission grating, the spectrometer based on the volume-phase holographic transmission grating has satisfactory high resolution and wavelength accuracy. It has great promise to be widely used in the future.

  19. Study of a Quantum Framework for Search Based Software Engineering

    NASA Astrophysics Data System (ADS)

    Wu, Nan; Song, Fangmin; Li, Xiangdong

    2013-06-01

    The Search Based Software Engineering (SBSE) is widely used in the software engineering to identify optimal solutions. The traditional methods and algorithms used in SBSE are criticized due to their high costs. In this paper, we propose a rapid modified-Grover quantum searching method for SBSE, and theoretically this method can be applied to any search-space structure and any type of searching problems.

  20. Soft-core processor study for node-based architectures.

    SciTech Connect

    Van Houten, Jonathan Roger; Jarosz, Jason P.; Welch, Benjamin James; Gallegos, Daniel E.; Learn, Mark Walter

    2008-09-01

    Node-based architecture (NBA) designs for future satellite projects hold the promise of decreasing system development time and costs, size, weight, and power and positioning the laboratory to address other emerging mission opportunities quickly. Reconfigurable Field Programmable Gate Array (FPGA) based modules will comprise the core of several of the NBA nodes. Microprocessing capabilities will be necessary with varying degrees of mission-specific performance requirements on these nodes. To enable the flexibility of these reconfigurable nodes, it is advantageous to incorporate the microprocessor into the FPGA itself, either as a hardcore processor built into the FPGA or as a soft-core processor built out of FPGA elements. This document describes the evaluation of three reconfigurable FPGA based processors for use in future NBA systems--two soft cores (MicroBlaze and non-fault-tolerant LEON) and one hard core (PowerPC 405). Two standard performance benchmark applications were developed for each processor. The first, Dhrystone, is a fixed-point operation metric. The second, Whetstone, is a floating-point operation metric. Several trials were run at varying code locations, loop counts, processor speeds, and cache configurations. FPGA resource utilization was recorded for each configuration. Cache configurations impacted the results greatly; for optimal processor efficiency it is necessary to enable caches on the processors. Processor caches carry a penalty; cache error mitigation is necessary when operating in a radiation environment.

  1. The study of damage identification based on compressive sampling

    NASA Astrophysics Data System (ADS)

    Wang, Wentao; Wang, Peng; Zhou, Wensong; Li, Hui

    2015-04-01

    This paper proposes a novel and effective method to identify the damage in the 2-D beam via Lamb wave. Two problems in the structural damage identification: damage location and damage severity are solved based on the theory of compressive sampling (CS) which indicates that sparse or compressible signals can be reconstructed using just a few measurements. Because of the sparsity nature of the damage, a database of damage features is established via a sparse representation for damage identification and assessing. Specifically, this proposed method consists of two steps: damage database establishing and feature matching. In the first step, the features database of both the healthy structure and the damaged structure are represented by the Lamb wave which propagates in the 2-D beam. Then in the matching step, expressing the test modal feature as a linear combination of the bases of the over-complete reference feature database which is constructed by concatenating all modal features of all candidate damage locations builds a highly underdetermined linear system of equations with an underlying sparse representation, which can be correctly recovered by ℓ1-minimization based on CS theory; the non-zero entry in the recovered sparse representation directly identifies the damage location and severity. In addition, numerical simulation is conducted to verify the method. This method of identifying damage location and assessing damage severity, using limited Lamb wave features, obtains good result.

  2. ISPE: A knowledge-based system for fluidization studies

    SciTech Connect

    Reddy, S.

    1991-01-01

    Chemical engineers use mathematical simulators to design, model, optimize and refine various engineering plants/processes. This procedure requires the following steps: (1) preparation of an input data file according to the format required by the target simulator; (2) excecuting the simulation; and (3) analyzing the results of the simulation to determine if all specified goals'' are satisfied. If the goals are not met, the input data file must be modified and the simulation repeated. This multistep process is continued until satisfactory results are obtained. This research was undertaken to develop a knowledge based system, IPSE (Intelligent Process Simulation Environment), that can enhance the productivity of chemical engineers/modelers by serving as an intelligent assistant to perform a variety tasks related to process simulation. ASPEN, a widely used simulator by the US Department of Energy (DOE) at Morgantown Energy Technology Center (METC) was selected as the target process simulator in the project. IPSE, written in the C language, was developed using a number of knowledge-based programming paradigms: object-oriented knowledge representation that uses inheritance and methods, rulebased inferencing (includes processing and propagation of probabilistic information) and data-driven programming using demons. It was implemented using the knowledge based environment LASER. The relationship of IPSE with the user, ASPEN, LASER and the C language is shown in Figure 1.

  3. Noninvasive Polarimetric-Based Glucose Monitoring: An in Vivo Study

    PubMed Central

    Purvinis, Georgeanne; Cameron, Brent D; Altrogge, Douglas M

    2011-01-01

    Background: Since 1990, there has been significant research devoted toward development of a noninvasive physiological glucose sensor. In this article, we report on the use of optical polarimetry for the noninvasive measurement of physiological glucose concentration in the anterior chamber of the eye of New Zealand white (NZW) rabbits. Method: Measurements were acquired using a custom-designed laser-based optical polarimetry system in a total of seven NZW rabbits anesthetized using an isoflurane-only anesthesia protocol. Aqueous humor-based polarimetric measurements were obtained by coupling light through the anterior chamber of the eye. Blood glucose levels were first stabilized and then altered with intravenous dextrose and insulin administration and measured every 3–5 min with a standard glucometer and intermittently with a YSI 2300 glucose analyzer. Acquired polarimetric glucose signals are calibrated to measured blood glucose concentration. Results: Based on a total of 41 data points, Clarke error grid analysis indicated 93% in zone A, 7% in zone B, and 0% in zones C and D, with reference concentrations between 93 and 521 mg/dl. Errors in prediction are shown to be related to gross movement of the rabbit during the procedures, incurring time-varying corneal birefringence effects that directly affect the measured polarimetric signal. These effects can be compensated for with appropriate design modifications. Conclusions: An optical polarimetry technique was used for in vivo physiological glucose monitoring. The technique demonstrated provides a basis for the development of a noninvasive polarimetric glucose monitor for home, personal, or hospital use. PMID:21527109

  4. Nitrogen Trifluoride-Based Fluoride- Volatility Separations Process: Initial Studies

    SciTech Connect

    McNamara, Bruce K.; Scheele, Randall D.; Casella, Andrew M.; Kozelisky, Anne E.

    2011-09-28

    This document describes the results of our investigations on the potential use of nitrogen trifluoride as the fluorinating and oxidizing agent in fluoride volatility-based used nuclear fuel reprocessing. The conceptual process uses differences in reaction temperatures between nitrogen trifluoride and fuel constituents that produce volatile fluorides to achieve separations and recover valuable constituents. We provide results from our thermodynamic evaluations, thermo-analytical experiments, kinetic models, and provide a preliminary process flowsheet. The evaluations found that nitrogen trifluoride can effectively produce volatile fluorides at different temperatures dependent on the fuel constituent.

  5. Pentazole-based energetic ionic liquids: a computational study.

    PubMed

    Pimienta, Ian S O; Elzey, Sherrie; Boatz, Jerry A; Gordon, Mark S

    2007-02-01

    The structures of protonated pentazole cations (RN5H+), oxygen-containing anions such as N(NO2)2-, NO3-, and ClO4- and the corresponding ion pairs are investigated by ab initio quantum chemistry calculations. The stability of the pentazole cation is explored by examining the decomposition pathways of several monosubstituted cations (RN5H+) to yield N2 and the corresponding azidinium cation. The heats of formation of these cations, which are based on isodesmic (bond-type conserving) reactions, are calculated. The proton-transfer reaction from the cation to the anion is investigated.

  6. Uniformity studies in large area triple-GEM based detectors

    NASA Astrophysics Data System (ADS)

    Akl, M. Abi; Bouhali, O.; Castaneda, A.; Maghrbi, Y.; Mohamed, T.

    2016-10-01

    Gas Electron Multiplier (GEM) based detectors have been used in many applications since their introduction in 1997. Large areas, e.g. exceeding 30×30 cm2, of GEM detectors are foreseen in future experiments which puts stringent requirements on the uniformity of response across the detection area. We investigate the effect of small variations of several parameters that could affect the uniformity. Parameters such as the anode pitch, the gas gap, the size and the shape of the holes are investigated. Simulation results are presented and compared to previous experimental data.

  7. Study on torpedo fuze signal denoising method based on WPT

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Sun, Changcun; Zhang, Tao; Ren, Zhiliang

    2013-07-01

    Torpedo fuze signal denoising is an important action to ensure reliable operation of fuze. Based on the good characteristics of wavelet packet transform (WPT) in signal denoising, the paper used wavelet packet transform to denoise the fuze signal under a complex background interference, and a simulation of the denoising results with Matlab is performed. Simulation result shows that the WPT denoising method can effectively eliminate background noise exist in torpedo fuze target signal with higher precision and less distortion, leading to advance the reliability of torpedo fuze operation.

  8. Vandenberg Air Force Base Pressure Gradient Wind Study

    NASA Technical Reports Server (NTRS)

    Shafer, Jaclyn A.

    2013-01-01

    Warning category winds can adversely impact day-to-day space lift operations at Vandenberg Air Force Base (VAFB) in California. NASA's Launch Services Program and other programs at VAFB use wind forecasts issued by the 30 Operational Support Squadron Weather Flight (30 OSSWF) to determine if they need to limit activities or protect property such as a launch vehicle. The 30 OSSWF tasked the AMU to develop an automated Excel graphical user interface that includes pressure gradient thresholds between specific observing stations under different synoptic regimes to aid forecasters when issuing wind warnings. This required the AMU to determine if relationships between the variables existed.

  9. Solidification study of some Ni- and Co-base alloys

    NASA Technical Reports Server (NTRS)

    Jeanfils, C. L.

    1984-01-01

    An ongoing research program aims to characterize the solidification of several Ni- and Co-based commercial wrought type alloys. The techniques used and the data items sought are: (1) thermal analysis, liquidus, nonequilibrium solidus as a function of cooling rate, secondary reactions temperatures, incipient melting, progress of solidification as a function of temperature; (2) optical metallography, characteristic structures and secondary dendrite arm spacing as a function of cooling rate; (3) X-ray diffraction, identification of precipitates; and (4) SEM/EDAX, measure of microsegregation.

  10. Study on Base Management Pattern of Food Producing Enterprise

    NASA Astrophysics Data System (ADS)

    Zhang, Weibin

    When the food producing enterprises often comply with food safety regulations and industry management system passively, we need to consider can they transform their production and business pattern in order to avoid the food safety incidents completely? The answer is yes. The food producing enterprises can develop to the two directions of material planting and products in circulation through base management pattern substituting for the original operation pattern of in-plant processing and outside sales. The food producing enterprises should establish coordination and safe supervision mechanisms in order to achieve the management objectives of unified production, controllable risks and scale magnitude.

  11. Image preprocessing study on KPCA-based face recognition

    NASA Astrophysics Data System (ADS)

    Li, Xuan; Li, Dehua

    2015-12-01

    Face recognition as an important biometric identification method, with its friendly, natural, convenient advantages, has obtained more and more attention. This paper intends to research a face recognition system including face detection, feature extraction and face recognition, mainly through researching on related theory and the key technology of various preprocessing methods in face detection process, using KPCA method, focuses on the different recognition results in different preprocessing methods. In this paper, we choose YCbCr color space for skin segmentation and choose integral projection for face location. We use erosion and dilation of the opening and closing operation and illumination compensation method to preprocess face images, and then use the face recognition method based on kernel principal component analysis method for analysis and research, and the experiments were carried out using the typical face database. The algorithms experiment on MATLAB platform. Experimental results show that integration of the kernel method based on PCA algorithm under certain conditions make the extracted features represent the original image information better for using nonlinear feature extraction method, which can obtain higher recognition rate. In the image preprocessing stage, we found that images under various operations may appear different results, so as to obtain different recognition rate in recognition stage. At the same time, in the process of the kernel principal component analysis, the value of the power of the polynomial function can affect the recognition result.

  12. Experimental study on GMM-based speaker recognition

    NASA Astrophysics Data System (ADS)

    Ye, Wenxing; Wu, Dapeng; Nucci, Antonio

    2010-04-01

    Speaker recognition plays a very important role in the field of biometric security. In order to improve the recognition performance, many pattern recognition techniques have be explored in the literature. Among these techniques, the Gaussian Mixture Model (GMM) is proved to be an effective statistic model for speaker recognition and is used in most state-of-the-art speaker recognition systems. The GMM is used to represent the 'voice print' of a speaker through modeling the spectral characteristic of speech signals of the speaker. In this paper, we implement a speaker recognition system, which consists of preprocessing, Mel-Frequency Cepstrum Coefficients (MFCCs) based feature extraction, and GMM based classification. We test our system with TIDIGITS data set (325 speakers) and our own recordings of more than 200 speakers; our system achieves 100% correct recognition rate. Moreover, we also test our system under the scenario that training samples are from one language but test samples are from a different language; our system also achieves 100% correct recognition rate, which indicates that our system is language independent.

  13. [Study on the land use optimization based on PPI].

    PubMed

    Wu, Xiao-Feng; Li, Ting

    2012-03-01

    Land use type and managing method which is greatly influenced by human activities, is one of the most important factors of non-point pollution. Based on the collection and analysis of non-point pollution control methods and the concept of the three ecological fronts, 9 land use optimized scenarios were designed according to rationality analysis of the current land use situation in the 3 typed small watersheds in Miyun reservoir basin. Take Caojialu watershed for example to analyze and compare the influence to environment of different scenarios based on potential pollution index (PPI) and river section potential pollution index (R-PPI) and the best combination scenario was found. Land use scenario designing and comparison on basis of PPI and R-PPI could help to find the best combination scenario of land use type and managing method, to optimize space distribution and managing methods of land use in basin, to reduce soil erosion and to provide powerful support to formulation of land use planning and pollution control project.

  14. Exploring a Model of Study Time Allocation in a Problem-Based Medical Curriculum.

    ERIC Educational Resources Information Center

    Gijselaers, Wim H.; Schmidt, Henk G.

    A study was done of the relation of time for individual study versus instruction time in a non-traditional, problem-based medical curriculum at the University of Limburg (Netherlands). The study collected data on 86 courses conducted in 5 consecutive academic years. In this problem-based approach, each curriculum year in the first 4 years…

  15. Power comparison between population-based case–control studies and family-based transmission–disequilibrium tests: An empirical study

    PubMed Central

    Haldar, Tanushree; Ghosh, Saurabh

    2011-01-01

    BACKGROUND: There are two major classes of genetic association analyses: population based and family based. Population-based case–control studies have been the method of choice due to the ease of data collection. However, population stratification is one of the major limitations of case–control studies, while family-based studies are protected against stratification. In this study, we carry out extensive simulations under different disease models (both Mendelian as well as complex) to evaluate the relative powers of the two approaches in detecting association. MATERIALS AND METHODS: The power comparisons are based on a case–control design comprising 200 cases and 200 controls versus a Transmission Disequilibrium Test (TDT) or Pedigree Disequilibrium Test (PDT) design with 200 informative trios. We perform the allele-level test for case–control studies, which is based on the difference of allele frequencies at a single nucleotide polymorphism (SNP) between unrelated cases and controls. The TDT and the PDT are based on preferential allelic transmissions at a SNP from heterozygous parents to the affected offspring. We considered five disease modes of inheritance: (i) recessive with complete penetrance (ii) dominant with complete penetrance and (iii), (iv) and (v) complex diseases with varying levels of penetrances and phenocopies. RESULTS: We find that while the TDT/PDT design with 200 informative trios is in general more powerful than a case–control design with 200 cases and 200 controls (except when the heterozygosity at the marker locus is high), it may be necessary to sample a very large number of trios to obtain the requisite number of informative families. CONCLUSION: The current study provides insights into power comparisons between population-based and family-based association studies. PMID:21747584

  16. Integrated Genome-Based Studies of Shewanella Echophysiology

    SciTech Connect

    Margrethe H. Serres

    2012-06-29

    Shewanella oneidensis MR-1 is a motile, facultative {gamma}-Proteobacterium with remarkable respiratory versatility; it can utilize a range of organic and inorganic compounds as terminal electronacceptors for anaerobic metabolism. The ability to effectively reduce nitrate, S0, polyvalent metals andradionuclides has established MR-1 as an important model dissimilatory metal-reducing microorganism for genome-based investigations of biogeochemical transformation of metals and radionuclides that are of concern to the U.S. Department of Energy (DOE) sites nationwide. Metal-reducing bacteria such as Shewanella also have a highly developed capacity for extracellular transfer of respiratory electrons to solid phase Fe and Mn oxides as well as directly to anode surfaces in microbial fuel cells. More broadly, Shewanellae are recognized free-living microorganisms and members of microbial communities involved in the decomposition of organic matter and the cycling of elements in aquatic and sedimentary systems. To function and compete in environments that are subject to spatial and temporal environmental change, Shewanella must be able to sense and respond to such changes and therefore require relatively robust sensing and regulation systems. The overall goal of this project is to apply the tools of genomics, leveraging the availability of genome sequence for 18 additional strains of Shewanella, to better understand the ecophysiology and speciation of respiratory-versatile members of this important genus. To understand these systems we propose to use genome-based approaches to investigate Shewanella as a system of integrated networks; first describing key cellular subsystems - those involved in signal transduction, regulation, and metabolism - then building towards understanding the function of whole cells and, eventually, cells within populations. As a general approach, this project will employ complimentary "top-down" - bioinformatics-based genome functional predictions, high

  17. Study on typhoon characteristic based on bridge health monitoring system.

    PubMed

    Wang, Xu; Chen, Bin; Sun, Dezhang; Wu, Yinqiang

    2014-01-01

    Through the wind velocity and direction monitoring system installed on Jiubao Bridge of Qiantang River, Hangzhou city, Zhejiang province, China, a full range of wind velocity and direction data was collected during typhoon HAIKUI in 2012. Based on these data, it was found that, at higher observed elevation, turbulence intensity is lower, and the variation tendency of longitudinal and lateral turbulence intensities with mean wind speeds is basically the same. Gust factor goes higher with increasing mean wind speed, and the change rate obviously decreases as wind speed goes down and an inconspicuous increase occurs when wind speed is high. The change of peak factor is inconspicuous with increasing time and mean wind speed. The probability density function (PDF) of fluctuating wind speed follows Gaussian distribution. Turbulence integral scale increases with mean wind speed, and its PDF does not follow Gaussian distribution. The power spectrum of observation fluctuating velocity is in accordance with Von Karman spectrum.

  18. Study on USB Based CAN Bus for Data Measurement System

    NASA Astrophysics Data System (ADS)

    Wu, Weibin; Hong, Tiansheng; Zhu, Yuqing; He, Guangbin; Ye, Cheng; Li, Haobiao; Chen, Chuwen

    Control area network (CAN) is an international protocol of field bus and universal serial bus (USB) is developing more and more widely. On the other hand, the USB technology combined with the CAN application is still in the development stage, so this research has broad prospects. The USB-based CAN bus system hardware consists of a CAN module, a USB communication module and a micro controller. It has been designed for real-time display and can save the CAN bus message. In addition it has been debugged in actual measurement accompanied by the Kvaser USB CAN II. The test results show that the system can correctly receive all messages frame from Kvaser CanKing. Finally the system has been applied to the project of citrus orchard for transmission of data of the citrus and tree parameters.

  19. Study of dynamic weighing system based on photoelectric detecting technique

    NASA Astrophysics Data System (ADS)

    Song, Gui-cai; Na, Yan-xiang; Cao, Shi-hao; Yang, Fei-yu

    2011-08-01

    Dynamic weighing is a process that it reckons the weight of vehicles according to measuring the tires which are moving. It makes use of sensors and some others auxiliary apparatus to measure the appearance of a certain vehicle and tires, then calculates the weight and the speed of vehicles. Finally it can note and read this information. To analyze the dynamic weighing system at home and abroad, it can be easily discovered that these are based on the sensors of electricity. The disadvantages of those sensors are very obvious. For example, when vehicles are dynamic weighed, the speed and accuracy can not be ensured at the same time. Dynamic weighing system is designed in the research of papers. Linear CCD can be used as Sensor to be applied in the mold of weighing. This paper describes the dynamic weighing system, analyses the dynamic of the system, and also investigates the modules of the dynamic weighing system.

  20. Smartphone-Based Cardiac Rehabilitation Program: Feasibility Study.

    PubMed

    Chung, Heewon; Ko, Hoon; Thap, Tharoeun; Jeong, Changwon; Noh, Se-Eung; Yoon, Kwon-Ha; Lee, Jinseok

    2016-01-01

    We introduce a cardiac rehabilitation program (CRP) that utilizes only a smartphone, with no external devices. As an efficient guide for cardiac rehabilitation exercise, we developed an application to automatically indicate the exercise intensity by comparing the estimated heart rate (HR) with the target heart rate zone (THZ). The HR is estimated using video images of a fingertip taken by the smartphone's built-in camera. The introduced CRP app includes pre-exercise, exercise with intensity guidance, and post-exercise. In the pre-exercise period, information such as THZ, exercise type, exercise stage order, and duration of each stage are set up. In the exercise with intensity guidance, the app estimates HR from the pulse obtained using the smartphone's built-in camera and compares the estimated HR with the THZ. Based on this comparison, the app adjusts the exercise intensity to shift the patient's HR to the THZ during exercise. In the post-exercise period, the app manages the ratio of the estimated HR to the THZ and provides a questionnaire on factors such as chest pain, shortness of breath, and leg pain during exercise, as objective and subjective evaluation indicators. As a key issue, HR estimation upon signal corruption due to motion artifacts is also considered. Through the smartphone-based CRP, we estimated the HR accuracy as mean absolute error and root mean squared error of 6.16 and 4.30bpm, respectively, with signal corruption due to motion artifacts being detected by combining the turning point ratio and kurtosis. PMID:27551969

  1. A Physics-Based Modeling Framework for Prognostic Studies

    NASA Technical Reports Server (NTRS)

    Kulkarni, Chetan S.

    2014-01-01

    Prognostics and Health Management (PHM) methodologies have emerged as one of the key enablers for achieving efficient system level maintenance as part of a busy operations schedule, and lowering overall life cycle costs. PHM is also emerging as a high-priority issue in critical applications, where the focus is on conducting fundamental research in the field of integrated systems health management. The term diagnostics relates to the ability to detect and isolate faults or failures in a system. Prognostics on the other hand is the process of predicting health condition and remaining useful life based on current state, previous conditions and future operating conditions. PHM methods combine sensing, data collection, interpretation of environmental, operational, and performance related parameters to indicate systems health under its actual application conditions. The development of prognostics methodologies for the electronics field has become more important as more electrical systems are being used to replace traditional systems in several applications in the aeronautics, maritime, and automotive fields. The development of prognostics methods for electronics presents several challenges due to the great variety of components used in a system, a continuous development of new electronics technologies, and a general lack of understanding of how electronics fail. Similarly with electric unmanned aerial vehicles, electrichybrid cars, and commercial passenger aircraft, we are witnessing a drastic increase in the usage of batteries to power vehicles. However, for battery-powered vehicles to operate at maximum efficiency and reliability, it becomes crucial to both monitor battery health and performance and to predict end of discharge (EOD) and end of useful life (EOL) events. We develop an electrochemistry-based model of Li-ion batteries that capture the significant electrochemical processes, are computationally efficient, capture the effects of aging, and are of suitable

  2. Studying disorder in graphite-based systems by Raman spectroscopy.

    PubMed

    Pimenta, M A; Dresselhaus, G; Dresselhaus, M S; Cançado, L G; Jorio, A; Saito, R

    2007-03-21

    Raman spectroscopy has historically played an important role in the structural characterization of graphitic materials, in particular providing valuable information about defects, stacking of the graphene layers and the finite sizes of the crystallites parallel and perpendicular to the hexagonal axis. Here we review the defect-induced Raman spectra of graphitic materials from both experimental and theoretical standpoints and we present recent Raman results on nanographites and graphenes. The disorder-induced D and D' Raman features, as well as the G'-band (the overtone of the D-band which is always observed in defect-free samples), are discussed in terms of the double-resonance (DR) Raman process, involving phonons within the interior of the 1st Brillouin zone of graphite and defects. In this review, experimental results for the D, D' and G' bands obtained with different laser lines, and in samples with different crystallite sizes and different types of defects are presented and discussed. We also present recent advances that made possible the development of Raman scattering as a tool for very accurate structural analysis of nano-graphite, with the establishment of an empirical formula for the in- and out-of-plane crystalline size and even fancier Raman-based information, such as for the atomic structure at graphite edges, and the identification of single versus multi-graphene layers. Once established, this knowledge provides a powerful machinery to understand newer forms of sp(2) carbon materials, such as the recently developed pitch-based graphitic foams. Results for the calculated Raman intensity of the disorder-induced D-band in graphitic materials as a function of both the excitation laser energy (E(laser)) and the in-plane size (L(a)) of nano-graphites are presented and compared with experimental results. The status of this research area is assessed, and opportunities for future work are identified.

  3. Smartphone-Based Cardiac Rehabilitation Program: Feasibility Study.

    PubMed

    Chung, Heewon; Ko, Hoon; Thap, Tharoeun; Jeong, Changwon; Noh, Se-Eung; Yoon, Kwon-Ha; Lee, Jinseok

    2016-01-01

    We introduce a cardiac rehabilitation program (CRP) that utilizes only a smartphone, with no external devices. As an efficient guide for cardiac rehabilitation exercise, we developed an application to automatically indicate the exercise intensity by comparing the estimated heart rate (HR) with the target heart rate zone (THZ). The HR is estimated using video images of a fingertip taken by the smartphone's built-in camera. The introduced CRP app includes pre-exercise, exercise with intensity guidance, and post-exercise. In the pre-exercise period, information such as THZ, exercise type, exercise stage order, and duration of each stage are set up. In the exercise with intensity guidance, the app estimates HR from the pulse obtained using the smartphone's built-in camera and compares the estimated HR with the THZ. Based on this comparison, the app adjusts the exercise intensity to shift the patient's HR to the THZ during exercise. In the post-exercise period, the app manages the ratio of the estimated HR to the THZ and provides a questionnaire on factors such as chest pain, shortness of breath, and leg pain during exercise, as objective and subjective evaluation indicators. As a key issue, HR estimation upon signal corruption due to motion artifacts is also considered. Through the smartphone-based CRP, we estimated the HR accuracy as mean absolute error and root mean squared error of 6.16 and 4.30bpm, respectively, with signal corruption due to motion artifacts being detected by combining the turning point ratio and kurtosis.

  4. Smartphone-Based Cardiac Rehabilitation Program: Feasibility Study

    PubMed Central

    Chung, Heewon; Yoon, Kwon-Ha; Lee, Jinseok

    2016-01-01

    We introduce a cardiac rehabilitation program (CRP) that utilizes only a smartphone, with no external devices. As an efficient guide for cardiac rehabilitation exercise, we developed an application to automatically indicate the exercise intensity by comparing the estimated heart rate (HR) with the target heart rate zone (THZ). The HR is estimated using video images of a fingertip taken by the smartphone’s built-in camera. The introduced CRP app includes pre-exercise, exercise with intensity guidance, and post-exercise. In the pre-exercise period, information such as THZ, exercise type, exercise stage order, and duration of each stage are set up. In the exercise with intensity guidance, the app estimates HR from the pulse obtained using the smartphone’s built-in camera and compares the estimated HR with the THZ. Based on this comparison, the app adjusts the exercise intensity to shift the patient’s HR to the THZ during exercise. In the post-exercise period, the app manages the ratio of the estimated HR to the THZ and provides a questionnaire on factors such as chest pain, shortness of breath, and leg pain during exercise, as objective and subjective evaluation indicators. As a key issue, HR estimation upon signal corruption due to motion artifacts is also considered. Through the smartphone-based CRP, we estimated the HR accuracy as mean absolute error and root mean squared error of 6.16 and 4.30bpm, respectively, with signal corruption due to motion artifacts being detected by combining the turning point ratio and kurtosis. PMID:27551969

  5. Adverse events among high-risk participants in a home-based walking study: a descriptive study

    PubMed Central

    Goodrich, David E; Larkin, Angela R; Lowery, Julie C; Holleman, Robert G; Richardson, Caroline R

    2007-01-01

    Background For high-risk individuals and their healthcare providers, finding the right balance between promoting physical activity and minimizing the risk of adverse events can be difficult. More information on the prevalence and influence of adverse events is needed to improve providers' ability to prescribe effective and safe exercise programs for their patients. Methods This study describes the type and severity of adverse events reported by participants with cardiovascular disease or at-risk for cardiovascular disease that occurred during an unsupervised, home-based walking study. This multi-site, randomized controlled trial tested the feasibility of a diet and lifestyle activity intervention over 1.5 years. At month 13, 274 eligible participants (male veterans) were recruited who were ambulatory, BMI > 28, and reporting one or more cardiovascular disease risk factors. All participants attended five, face-to-face dietitian-delivered counseling sessions during the six-month intervention. Participants were randomized to three study arms: 1) time-based walking goals, 2) simple pedometer-based walking goals, and 3) enhanced pedometer-based walking goals with Internet-mediated feedback. Two physicians verified adverse event symptom coding. Results Enrolled participants had an average of five medical comorbidities. During 1110 person months of observation, 87 of 274 participants reported 121 adverse events. One serious study-related adverse event (atrial fibrillation) was reported; the individual resumed study participation within three days. Non-serious, study related adverse events made up 12% of all symptoms – predominantly minor musculoskeletal events. Serious, non-study related adverse events represented 32% of all symptoms while non-serious, non-study related adverse events made up 56% of symptoms. Cardiovascular disease events represented over half of the non-study related adverse event symptoms followed by musculoskeletal complaints. Adverse events caused

  6. A method for MREIT-based source imaging: simulation studies.

    PubMed

    Song, Yizhuang; Jeong, Woo Chul; Woo, Eung Je; Seo, Jin Keun

    2016-08-01

    This paper aims to provide a method for using magnetic resonance electrical impedance tomography (MREIT) to visualize local conductivity changes associated with evoked neuronal activities in the brain. MREIT is an MRI-based technique for conductivity mapping by probing the magnetic flux density induced by an externally injected current through surface electrodes. Since local conductivity changes resulting from evoked neural activities are very small (less than a few %), a major challenge is to acquire exogenous magnetic flux density data exceeding a certain noise level. Noting that the signal-to-noise ratio is proportional to the square root of the number of averages, it is important to reduce the data acquisition time to get more averages within a given total data collection time. The proposed method uses a sub-sampled k-space data set in the phase-encoding direction to significantly reduce the data acquisition time. Since the sub-sampled data violates the Nyquist criteria, we only get a nonlinearly wrapped version of the exogenous magnetic flux density data, which is insufficient for conductivity imaging. Taking advantage of the sparseness of the conductivity change, the proposed method detects local conductivity changes by estimating the time-change of the Laplacian of the nonlinearly wrapped data. PMID:27401235

  7. DFT Study of Optical Properties of Pt-based Complexes

    NASA Astrophysics Data System (ADS)

    Oprea, Corneliu I.; Dumbravǎ, Anca; Moscalu, Florin; Nicolaides, Atnanassios; Gîrţu, Mihai A.

    2010-01-01

    We report Density Functional Theory (DFT) calculations providing the geometrical and electronic structures, as well as the vibrational and optical properties of the homologous series of Pt-pyramidalized olefin complexes (CH2)n-(C8H10)Pt(PH3)2, where n = 0, 1, and 2, in their neutral and oxidized states. All complexes were geometry optimized for the singlet ground state in vacuum using DFT methods with B3LYP exchange-correlation functional and the Effective Core Potential LANL2DZ basis set, within the frame of Gaussian03 quantum chemistry package. We find the coordination geometry of Pt to be distorted square planar, with dihedral angles ranging from 0°, for n = 0 and 1, which have C2V symmetry to 3.4°, for n = 2 with C2 symmetry. The Mulliken charge analysis allows a discussion of the oxidation state of the Pt ion. Electronic transitions were calculated at the same level of theory by means of Time Dependant-DFT. For n = 2 the electronic absorption bands are located in the UV region of the spectrum, the transitions being assigned to metal to ligand charge transfers. The relevance of these Pt-based compounds as possible pigments for dye-sensitized solar cells is discussed.

  8. Study on GIS-based sport-games information system

    NASA Astrophysics Data System (ADS)

    Peng, Hongzhi; Yang, Lingbin; Deng, Meirong; Han, Yongshun

    2008-10-01

    With the development of internet and such info-technologies as, Information Superhighway, Computer Technology, Remote Sensing(RS), Global Positioning System(GPS), Digital Communication and National Information Network(NIN),etc. Geographic Information System (GIS) becomes more and more popular in fields of science and industries. It is not only feasible but also necessary to apply GIS to large-scale sport games. This paper firstly discussed GIS technology and its application, then elaborated on the frame and content of Sport-Games Geography Information System(SG-GIS) with the function of gathering, storing, processing, sharing, exchanging and utilizing all kind of spatial-temporal information about sport games, and lastly designed and developed a public service GIS for the 6th Asian Winter Games in Changchun, China(CAWGIS). The application of CAWGIS showed that the established SG-GIS was feasible and GIS-based sport games information system was able to effectively process a large amount of sport-games information and provide the real-time sport games service for governors, athletes and the public.

  9. Compatibility studies of metallic materials with lithium-based oxides

    NASA Astrophysics Data System (ADS)

    Hofmann, P.; Dienst, W.

    1988-07-01

    The compatibility of Li 2O, Li 4SiO 4 and Li 2SiO 3 with the cladding materials AISI 316, 1.4914, Hastelloy X and Inconel 625 was investigated at 800-1000°C for annealing times up to 1000 h. A controlled oxygen reactivity was established by adding 1 mol% NiO per mole Li 2O to the Li-based oxides. In addition, some compatibility tests were performed at 600-900°C on Be, which is of interest as a neutron multiplier material, with Li 2SiO 3 as well as AISI 316. Li 2O accounted for the strongest cladding attack, followed by Li 4SiO 4 and Li 2SiO 3. In the absence of NiO, Li 2SiO 3 caused no chemical interactions at all. With respect to the cladding materials, there was no considerable difference in the reaction rates of AISI 316, Hastelloy X and Inconel 625. However, the steel 1.4914 was clearly more heavily attacked at and above 800°C. The compatibility of Be with Li 2SiO 3 or AISI 316 seems to be tolerable up to about 650°C. At higher temperatures a liquid Li suicide phase is formed which results in strong local attack and penetration into Li 2SiO 3.

  10. An Analysis of Excavation Support Safety Based on Experimental Studies

    NASA Astrophysics Data System (ADS)

    Gorska, Karolina; Wyjadłowski, Marek

    2015-09-01

    The article presents the results of inclinometric measurements and numerical analyses of soldier-pile wall displacements. The excavation under investigation was made in cohesive soils. The measurements were conducted at points located at the edge of the cantilever excavation support system. The displacements of the excavation support observed over the period of three years demonstrated the pattern of steady growth over the first two months, followed by a gradual levelling out to a final plateau. The numerical analyses were conducted based on 3D FEM models. The numerical analysis of the problem comprise calculations of the global structural safety factor depending on the displacement of the chosen points in the lagging and conducted by means of the φ/c reduction procedure. The adopted graphical method of safety estimation is very conservative in the sense that it recognizes stability loss quite early, when one could further load the medium or weaken it by further strength reduction. The values of the Msf factor are relatively high. This is caused by the fact that the structure was designed for excavation twice as deep. Nevertheless, the structure is treated as a temporary one.

  11. A method for MREIT-based source imaging: simulation studies

    NASA Astrophysics Data System (ADS)

    Song, Yizhuang; Jeong, Woo Chul; Woo, Eung Je; Seo, Jin Keun

    2016-08-01

    This paper aims to provide a method for using magnetic resonance electrical impedance tomography (MREIT) to visualize local conductivity changes associated with evoked neuronal activities in the brain. MREIT is an MRI-based technique for conductivity mapping by probing the magnetic flux density induced by an externally injected current through surface electrodes. Since local conductivity changes resulting from evoked neural activities are very small (less than a few %), a major challenge is to acquire exogenous magnetic flux density data exceeding a certain noise level. Noting that the signal-to-noise ratio is proportional to the square root of the number of averages, it is important to reduce the data acquisition time to get more averages within a given total data collection time. The proposed method uses a sub-sampled k-space data set in the phase-encoding direction to significantly reduce the data acquisition time. Since the sub-sampled data violates the Nyquist criteria, we only get a nonlinearly wrapped version of the exogenous magnetic flux density data, which is insufficient for conductivity imaging. Taking advantage of the sparseness of the conductivity change, the proposed method detects local conductivity changes by estimating the time-change of the Laplacian of the nonlinearly wrapped data.

  12. Study of vertical breakwater reliability based on copulas

    NASA Astrophysics Data System (ADS)

    Dong, Sheng; Li, Jingjing; Li, Xue; Wei, Yong

    2016-04-01

    The reliability of a vertical breakwater is calculated using direct integration methods based on joint density functions. The horizontal and uplifting wave forces on the vertical breakwater can be well fitted by the lognormal and the Gumbel distributions, respectively. The joint distribution of the horizontal and uplifting wave forces is analyzed using different probabilistic distributions, including the bivariate logistic Gumbel distribution, the bivariate lognormal distribution, and three bivariate Archimedean copulas functions constructed with different marginal distributions simultaneously. We use the fully nested copulas to construct multivariate distributions taking into account related variables. Different goodness fitting tests are carried out to determine the best bivariate copula model for wave forces on a vertical breakwater. We show that a bivariate model constructed by Frank copula gives the best reliability analysis, using marginal distributions of Gumbel and lognormal to account for uplifting pressure and horizontal wave force on a vertical breakwater, respectively. The results show that failure probability of the vertical breakwater calculated by multivariate density function is comparable to those by the Joint Committee on Structural Safety methods. As copulas are suitable for constructing a bivariate or multivariate joint distribution, they have great potential in reliability analysis for other coastal structures.

  13. [Progress of anti-tumor study based on BRAF].

    PubMed

    Yan, Gui-Rui; Xu, Zhi-Jian; Wang, He-Yao; Zhu, Wei-Liang

    2012-12-01

    BRAF is one of the most important pro-oncogenes, which is mutated in approximately 8% of human tumors. The most common BRAF mutation is a valine-to-glutamate transition (V600E) that is expressed primarily in melanoma, colorectal cancer and thyroid carcinoma. MEK/ERK is constitutively activated in the cells expressing BRAFV600E, leading to tumor development, invasion, and metastasis. Therefore, BRAFV600E is a therapeutic target for melanoma and some other BRAFV600E tumors. Vemurafenib, a BRAFV600E inhibitor, which was approved by FDA for the treatment of late-stage melanoma in 2011, produces improved rates of overall and progression-free survival in patients with the BRAFV600E mutation, making a dramatic breakthrough in melanoma treatment. Vemurafenib is also an individual target drug based on genetic diagnosis. However, its therapeutic success is limited by the emergence of drug resistance. Therefore, it is important to explore the mechanisms underlying the resistance for developing new inhibitor drugs and for preventing or delaying the resistance evolution to BRAF inhibitor drugs. In this review, we described the role of BRAFV600E as an anti-tumor drug target and the development of BRAF inhibitors. We also discussed the mechanisms leading to resistance of BRAFV600E inhibitors. Furthermore, therapeutic strategies that might be employed to overcome acquired resistance were proposed.

  14. Implementation of Anaphylaxis Management Guidelines: A Register-Based Study

    PubMed Central

    Grabenhenrich, Linus; Hompes, Stephanie; Gough, Hannah; Ruëff, Franziska; Scherer, Kathrin; Pföhler, Claudia; Treudler, Regina; Mahler, Vera; Hawranek, Thomas; Nemat, Katja; Koehli, Alice; Keil, Thomas; Worm, Margitta

    2012-01-01

    Background Anaphylaxis management guidelines recommend the use of intramuscular adrenaline in severe reactions, complemented by antihistamines and corticoids; secondary prevention includes allergen avoidance and provision of self-applicable first aid drugs. Gaps between recommendations and their implementation have been reported, but only in confined settings. Hence, we analysed nation-wide data on the management of anaphylaxis, evaluating the implementation of guidelines. Methods Within the anaphylaxis registry, allergy referral centres across Germany, Austria and Switzerland provided data on severe anaphylaxis cases. Based on patient records, details on reaction circumstances, diagnostic workup and treatment were collected via online questionnaire. Report of anaphylaxis through emergency physicians allowed for validation of registry data. Results 2114 severe anaphylaxis patients from 58 centres were included. 8% received adrenaline intravenously, 4% intramuscularly; 50% antihistamines, and 51% corticoids. Validation data indicated moderate underreporting of first aid drugs in the Registry. 20% received specific instructions at the time of the reaction; 81% were provided with prophylactic first aid drugs at any time. Conclusion There is a distinct discrepancy between current anaphylaxis management guidelines and their implementation. To improve patient care, a revised approach for medical education and training on the management of severe anaphylaxis is warranted. PMID:22590513

  15. Cathodoluminescence Emission Studies for Selected Phosphor-Based Sensor Materials

    SciTech Connect

    Goedeke, Shawn; Hollerman, William Andrew; Allison, Stephen W; Gray, P A; Lewis, Linda A; Smithwick III, Robert W; Boatner, Lynn A; Glasgow, David C; Ivanov, Ilia N; Wise, H.

    2005-01-01

    The current interest in returning to the Moon and Mars by 2030 makes cost effective and low mass health monitoring sensors essential for spacecraft development. In space, there are many surface measurements that are required to monitor the condition of the spacecraft including: surface temperature, radiation dose, and impact. Through the use of phosphors, these conditions can be monitored. Practical space-based phosphor sensors will depend heavily upon research investigating the resistance of phosphors to ionizing radiation and the ability to anneal or self-heal from damage caused by ionizing radiation. The cathodoluminescence (CL) testing was performed using the low energy electron system located at the NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama. For the materials tested, several interesting results were observed. For most materials, increases in both beam energy and current density improved the CL fluorescence yield. It was also noted that YAG:Nd,Ce has the greatest near infrared intensity for any of the tested materials. The evaluation of dopant concentration in YPO{sub 4}:Nd showed minimal differences in spectral shape and intensity. While the total electron dose was small, the intention was to maximize the number of irradiated materials.

  16. A Comparison of Traditional Teaching Methods and Problem-Based Learning in an Addiction Studies Class.

    ERIC Educational Resources Information Center

    Sevening, Diane; Baron, Mark

    2002-01-01

    Study compared students' achievement gains and attitudes using traditional (lecture-based) teaching methods and problem-based learning (PBL) techniques in an addiction studies class. Results showed students did not respond well to PBL and preferred a lecture-based format. Pretest mean scores indicated the PBL group entered the course at a higher…

  17. Activity-Based Teaching in Social Studies Education: An Action Research

    ERIC Educational Resources Information Center

    Akkus, Zekerya

    2015-01-01

    The aim of this study was to determine pre-service social studies teachers' skills to plan and apply the activity-based teaching and contribute to their development of these skills. In the study, the action research design of qualitative research was used. The sample of the study consisted of 6 pre-service teachers who were 4th year students at…

  18. A Computer Game-Based Method for Studying Bullying and Cyberbullying

    ERIC Educational Resources Information Center

    Mancilla-Caceres, Juan F.; Espelage, Dorothy; Amir, Eyal

    2015-01-01

    Even though previous studies have addressed the relation between face-to-face bullying and cyberbullying, none have studied both phenomena simultaneously. In this article, we present a computer game-based method to study both types of peer aggression among youth. Study participants included fifth graders (N = 93) in two U.S. Midwestern middle…

  19. A Study on Components of Internal Control-Based Administrative System in Secondary Schools

    ERIC Educational Resources Information Center

    Montri, Paitoon; Sirisuth, Chaiyuth; Lammana, Preeda

    2015-01-01

    The aim of this study was to study the components of the internal control-based administrative system in secondary schools, and make a Confirmatory Factor Analysis (CFA) to confirm the goodness of fit of empirical data and component model that resulted from the CFA. The study consisted of three steps: 1) studying of principles, ideas, and theories…

  20. Study of magnetization switching for MRAM based memory technologies

    NASA Astrophysics Data System (ADS)

    Pham, Huy

    Amphibian alkaloids are attractive targets for synthesis due to their biological activity. An important class of amphibian alkaloids is the 2,5-disubstituted pyrrolidine-based family of compounds. There are many synthetic approaches for the preparation of the trans-2,5-disubstituted pyrrolidines, but methods for the construction of the cis-2,5-pyrrolidines are limited. Therefore, it was desired to develop an enantioselective approach for the preparation of cis-2,5-disubsituted pyrrolidines. (+)-Tropin-2-one derived from cocaine was used as starting material to exploit the inherent stereochemistry for construction of the cis-pyrrolidine ring. This permitted the unequivocal assignment of the absolute configuration of the target pyrrolidine. The structurally simple pyrrolidine alkaloid, 225H, was selected as a target to develop a general synthetic approach. The enantioselective synthesis of 225H was achieved in nine steps and good overall yield. The search for potent cannabinoid receptor partial agonist ligands as potential marijuana addiction therapeutic agents has led to an investigation of the synthesis of diaryl ether hybrid analogues of BAY 59-3074. A series of 2-(3-alkyl-5-hydroxyphenoxy)-6-(trifluoromethyl)benzonitriles, 3-(2-cyano-3-(trifluoromethyl)phenoxy)phenylalkanoates, and (3-(benzyloxy)phenoxy)-6-(trifluoromethyl)benzonitriles were synthesized and evaluated in vitro for CB1 affinity. The olivetol diaryl ether analogue was the most potent ligand of the alkyl series, but the diaryl ester analogues exhibited modest affinity for CB1 receptors. The most potent compound of the series was the 2-(3-(benzyloxy)phenoxy)-6-(trifluoromethyl)benzonitrile. Keywords. amphibian alkaloids, enantioselective synthesis, pyrrolidine, cannabinoid receptor, marijuana.

  1. Integrated Genome-Based Studies of Shewanella Ecophysiology

    SciTech Connect

    Andrei L. Osterman, Ph.D.

    2012-12-17

    Integration of bioinformatics and experimental techniques was applied to mapping and characterization of the key components (pathways, enzymes, transporters, regulators) of the core metabolic machinery in Shewanella oneidensis and related species with main focus was on metabolic and regulatory pathways involved in utilization of various carbon and energy sources. Among the main accomplishments reflected in ten joint publications with other participants of Shewanella Federation are: (i) A systems-level reconstruction of carbohydrate utilization pathways in the genus of Shewanella (19 species). This analysis yielded reconstruction of 18 sugar utilization pathways including 10 novel pathway variants and prediction of > 60 novel protein families of enzymes, transporters and regulators involved in these pathways. Selected functional predictions were verified by focused biochemical and genetic experiments. Observed growth phenotypes were consistent with bioinformatic predictions providing strong validation of the technology and (ii) Global genomic reconstruction of transcriptional regulons in 16 Shewanella genomes. The inferred regulatory network includes 82 transcription factors, 8 riboswitches and 6 translational attenuators. Of those, 45 regulons were inferred directly from the genome context analysis, whereas others were propagated from previously characterized regulons in other species. Selected regulatory predictions were experimentally tested. Integration of this analysis with microarray data revealed overall consistency and provided additional layer of interactions between regulons. All the results were captured in the new database RegPrecise, which is a joint development with the LBNL team. A more detailed analysis of the individual subsystems, pathways and regulons in Shewanella spp included bioinfiormatics-based prediction and experimental characterization of: (i) N-Acetylglucosamine catabolic pathway; (ii)Lactate utilization machinery; (iii) Novel Nrt

  2. Comparative studies of praseodymium(III) selective sensors based on newly synthesized Schiff's bases.

    PubMed

    Gupta, Vinod K; Goyal, Rajendra N; Pal, Manoj K; Sharma, Ram A

    2009-10-27

    Praseodymium ion selective polyvinyl chloride (PVC) membrane sensors, based on two new Schiff's bases 1,3-diphenylpropane-1,3-diylidenebis(azan-1-ylidene)diphenol (M(1)) and N,N'-bis(pyridoxylideneiminato) ethylene (M(2)) have been developed and studied. The sensor having membrane composition of PVC: o-NPOE: ionophore (M(1)): NaTPB (w/w; mg) of 150: 300: 8: 5 showed best performances in comparison to M(2) based membranes. The sensor based on (M(1)) exhibits the working concentration range 1.0x10(-8) to 1.0x10(-2) M with a detection limit of 5.0x10(-9) M and a Nernstian slope 20.0+/-0.3 mV decade(-1) of activity. It exhibited a quick response time as <8 s and its potential responses were pH independent across the range of 3.5-8.5. The influence of the membrane composition and possible interfering ions have also been investigated on the response properties of the electrode. The sensor has been found to work satisfactorily in partially non-aqueous media up to 15% (v/v) content of methanol, ethanol or acetonitrile and could be used for a period of 3 months. The selectivity coefficients determined by using fixed interference method (FIM) indicate high selectivity for praseodymium(III) ions over wide variety of other cations. To asses its analytical applicability the prepared sensor was successfully applied for determination of praseodymium(III) in spiked water samples.

  3. Studying with the cloud: the use of online Web-based resources to augment a traditional study group format.

    PubMed

    Chan, Teresa; Sennik, Serena; Zaki, Amna; Trotter, Brendon

    2015-03-01

    Cloud-based applications such as Google Docs, Skype, Dropbox, and SugarSync are revolutionizing the way that we interact with the world. Members of the millennial generation (those born after 1980) are now becoming senior residents and junior attending physicians. We describe a novel technique combining Internet- and cloud-based methods to digitally augment the classic study group used by final-year residents studying for the Royal College of Physicians and Surgeons of Canada examination. This material was developed by residents and improved over the course of 18 months. This is an innovation report about a process for enhanced communication and collaboration as there has been little research to date regarding the augmentation of learner-driven initiatives with virtual resources. PMID:25927263

  4. The re-evaluation of the measurement of pain in population-based epidemiological studies: The SHAMA study

    PubMed Central

    Flüß, Elisa; Bond, Christine M; Jones, Gareth T

    2015-01-01

    Background: While many pain patients rely on pain-relieving treatments to manage their pain, pain-related research commonly quantifies pain status using validated questionnaires without taking into account that information. This will lead to an underestimate of the burden of pain in the community. To ensure a more accurate assessment of the prevalence and severity of pain, this study aimed to develop a pain management questionnaire and to assess how much population-based pain estimates change when pain management is considered. Methods: This study was a cross-sectional population-based study in Grampian, north-east Scotland. A total of 4600 people, aged 25 years and over, were randomly selected from a population sample frame and sent a questionnaire on pain and pain management. Population estimates of pain were determined twice: with the use of standard pain status questionnaires (‘current pain’) and with the use of a newly developed enhanced pain status questionnaire to determine patients’ estimated pain without pain management (‘all pain’). Results: The prevalence of current pain was 50.5% (95% CI = 48.0, 52.9). Of those who reported no current pain, 11.6% (95% CI = 9.4, 13.8) reported that they would have had pain had they not managed their pain. Thus, the all pain prevalence was 56.2% (95% CI = 53.7, 58.7). This difference in prevalence rates was statistically significant (difference = 5.7%; 95% CI = 2.2, 9.2). Likewise, participants’ pain severity significantly increased when they estimated their pain without pain management (p < 0.001, Wilcoxon-signed rank test). Conclusions: Failure to assess pain management information results in an underestimation of pain prevalence and severity. This should be considered in future epidemiological studies. Summary points Pain management information is currently not considered for the assessment of pain in epidemiological population-based studies. Since pain management can affect

  5. Design and conduct of an internet-based preconception cohort study in North America: Pregnancy Study Online (PRESTO)

    PubMed Central

    Wise, Lauren A; Rothman, Kenneth J.; Mikkelsen, Ellen M.; Stanford, Joseph B.; Wesselink, Amelia K.; McKinnon, Craig; Gruschow, Siobhan M.; Horgan, Casie E.; Wiley, Aleta S.; Hahn, Kristen A.; Sørensen, Henrik Toft; Hatch, Elizabeth E.

    2015-01-01

    Background We launched the Boston University Pregnancy Study Online (PRESTO) to assess the feasibility of carrying out an internet-based preconception cohort study in the U.S. and Canada. Methods We recruited female participants age 21–45 and their male partners through internet advertisements, word of mouth, and flyers. Female participants were randomized with 50% probability to receive a subscription to FertilityFriend.com (FF), a web-based program that collects real-time data on menstrual characteristics. We compared recruitment methods within PRESTO, assessed the cost-efficiency of PRESTO relative to its Danish counterpart (Snart-Gravid), and validated retrospectively-reported date of last menstrual period (LMP) against FF data. Results After 99 weeks of recruitment (2013–2015), 2,421 women enrolled; 1,384 (57%) invited their male partners to participate, of whom 693 (50%) enrolled. Baseline characteristics were balanced across randomization groups. Cohort retention was similar among those randomized vs. not randomized to FF (84% vs. 81%). At study enrollment, 56%, 22%, and 22% couples had been trying to conceive for <3, 3–5, and ≥6 months, respectively. The cost per subject enrolled was $146 (2013 $US), which was similar to our companion Danish study and half that of a traditional cohort study. Among FF users who conceived, >97% reported their LMP on the PRESTO questionnaire within 1 day of the LMP recorded via FF. Conclusions Use of the internet as a method of recruitment and follow-up in a North American preconception cohort study was feasible and cost-effective. PMID:26111445

  6. A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

    NASA Astrophysics Data System (ADS)

    Ültay, Neslihan; Çalık, Muammer

    2012-12-01

    Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords `context-based', `contextual learning' and `chemistry education' in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students' attitudes and students' understanding/cognition. Implications were investigated for practice in context- based chemistry studies, for future research in context- based chemistry studies, and for curriculum developers in context- based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students' motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant

  7. Collecting Biospecimens From an Internet-Based Prospective Cohort Study of Inflammatory Bowel Disease (CCFA Partners): A Feasibility Study

    PubMed Central

    Gulati, Ajay S; Cook, Suzanne F; Martin, Christopher F; Chen, Wenli; Jaeger, Elizabeth L; Schoenborn, Alexi A; Basta, Patricia V; Dejong, Hendrik; Luo, Jingchun; Gallant, Marisa; Sandler, Robert S; Long, Millie D; Kappelman, Michael D

    2016-01-01

    Background The Internet has successfully been used for patient-oriented survey research. Internet-based translational research may also be possible. Objective Our aim was to study the feasibility of collecting biospecimens from CCFA Partners, an Internet-based inflammatory bowel disease (IBD) cohort. Methods From August 20, 2013, to January 4, 2014, we randomly sampled 412 participants, plus 179 from a prior validation study, and invited them to contribute a biospecimen. Participants were randomized to type (blood, saliva), incentive (none, US $20, or US $50), and collection method for blood. The first 82 contributors were also invited to contribute stool. We used descriptive statistics and t tests for comparisons. Results Of the 591 participants, 239 (40.4%) indicated interest and 171 (28.9%) contributed a biospecimen. Validation study participants were more likely to contribute than randomly selected participants (44% versus 23%, P<.001). The return rate for saliva was higher than blood collected by mobile phlebotomist and at doctors’ offices (38%, 31%, and 17% respectively, P<.001). For saliva, incentives were associated with higher return rates (43-44% versus 26%, P=.04); 61% contributed stool. Fourteen IBD-associated single nucleotide polymorphisms were genotyped, and risk allele frequencies were comparable to other large IBD populations. Bacterial DNA was successfully extracted from stool samples and was of sufficient quality to permit quantitative polymerase chain reaction for total bacteria. Conclusions Participants are willing to contribute and it is feasible to collect biospecimens from an Internet-based IBD cohort. Home saliva kits yielded the highest return rate, though mobile phlebotomy was also effective. All samples were sufficient for genetic testing. These data support the feasibility of developing a centralized collection of biospecimens from this cohort to facilitate IBD translational studies. PMID:26732016

  8. Base Composition Effects Study on Nbr Current and Current Gain in SiGe Hbt

    NASA Astrophysics Data System (ADS)

    Davoodi, Hossen; Kaatuzian, Hassan

    2013-07-01

    In present study, SiGe Hetero-junction Bipolar Transistors (HBTs) performances are discussed based on both TCAD and analytical evaluations of the heavily doped base. It is demonstrated that neutral base recombination (NBR) current has significant effects on base current and hence current gain. An optimized Ge profile for 20 nm wide base of understudy structure, with 16% Germanium at EB edge and 24% at CB edge is concluded analytically, which improves DC and high frequency behavior. TCAD simulations reveal that for the specific structure and proposed profile, current gain is about 3500. It also exhibits ft and fmax about 325 GHz and 192 GHz, respectively. In the next section for the first time, a comprehensive study of early voltage variation based on total Ge content and Ge grading in base is also presented. Forced base-emitter voltage and forced base current configurations are studied separately. NBR current has been analyzed under two different configuration and prospective guidelines are indicated.

  9. Infrared thermography based magnetic hyperthermia study in Fe3O4 based magnetic fluids

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Ranoo, Surojit; Philip, John

    2016-09-01

    Owing to the immense clinical benefits, magnetic hyperthermia is likely to emerge as an alternate cancer therapeutic procedure in the near future. Presently, radio frequency immune fiber optic based sensors are being used to monitor temperature changes during magnetic hyperthermia measurements, which have inherent limitations due to the requirement of physical contact of the sensor with the sample, contamination and temperature monitoring at a single point. Here, we investigate the field induced heating of oil based oleic acid coated Fe3O4 nanofluid, synthesized using co-precipitation method, using infrared thermal imaging (IRT) camera and compare the results with those of fiber optic temperature sensor. Experiments were performed on nanofluid samples of four different concentrations and under five different external field amplitudes. The specific absorption rate (SAR) of the samples were determined from the initial rate of temperature rise measured using both the techniques. The SAR values determined from both the techniques were in very good agreement with each other, with in an accuracy of 5%, after incorporating convection loss correction on the infrared thermal imaging data. The consecutive thermal cycling on the samples showed good thermal stability and thermal recovery. The maximum SAR obtained was 95.9 W/gFe for a sample concentration and field amplitude of 23 wt.% and 57.3 kA m-1, respectively. This study showed the efficacy and accuracy of temperature measurement using IRT during field induced heating of magnetic nanofluid and its advantages over conventional point measurements techniques for real-time, non-contact and wide area temperature mapping without sample contamination.

  10. University of Wolverhampton Case Study: Embedding Practical Work-Based Modules into a Traditionally, Theoretical Programme

    ERIC Educational Resources Information Center

    Nicholls, Emma; Walsh, Margaret

    2007-01-01

    Purpose: This case study aims to provide a critical evaluation of the decision by the University of Wolverhampton's School of Legal Studies to develop a number of work-based learning modules, offered as part of the undergraduate programme. It seeks to examine why the School has taken the approach of embedding work-based learning into what has…

  11. A Case Study on Online Mathematics Teaching with Pen-Based Technology: Experiences of Two Instructors

    ERIC Educational Resources Information Center

    Karal, Hasan; Kokoc, Mehmet; Colak, Canan; Yalcin, Yasin

    2015-01-01

    The purpose of this study was to explore instructors' perspectives on the effect of using pen-based technology in the online mathematics courses and understand instructors' experiences in online mathematics teaching with pen-based technology. In this study, two instructors who taught online mathematics courses in fourteen weeks used digital pen as…

  12. Designing Web-Based Educative Curriculum Materials for the Social Studies

    ERIC Educational Resources Information Center

    Callahan, Cory; Saye, John; Brush, Thomas

    2013-01-01

    This paper reports on a design experiment of web-based curriculum materials explicitly created to help social studies teachers develop their professional teaching knowledge. Web-based social studies curriculum reform efforts, human-centered interface design, and investigations into educative curriculum materials are reviewed, as well as…

  13. CBSS Outreach Project: Computer-Based Study Strategies for Students with Learning Disabilities. Final Report.

    ERIC Educational Resources Information Center

    Anderson-Inman, Lynne; Ditson, Mary

    This final report describes activities and accomplishments of the four-year Computer-Based Study Strategies (CBSS) Outreach Project at the University of Oregon. This project disseminated information about using computer-based study strategies as an intervention for students with learning disabilities and provided teachers in participating outreach…

  14. Brain-Based Learning and Classroom Practice: A Study Investigating Instructional Methodologies of Urban School Teachers

    ERIC Educational Resources Information Center

    Morris, Lajuana Trezette

    2010-01-01

    The purpose of this study was to examine the implementation of brain-based instructional strategies by teachers serving at Title I elementary, middle, and high schools within the Memphis City School District. This study was designed to determine: (a) the extent to which Title I teachers applied brain-based strategies, (b) the differences in…

  15. Professional-Patron Influence on Site-Based Governance Councils: A Confounding Case Study.

    ERIC Educational Resources Information Center

    Malen, Betty; Ogawa, Rodney T.

    1988-01-01

    A case study of site-based governance councils in Salt Lake City (Utah) is described. The study was a test of whether building-based councils actually enable teachers and parents to exert substantial influence on school policy. The reason why research findings did not fit expectations is discussed. (SLD)

  16. The Effects of Study Tasks in a Computer-Based Chemistry Learning Environment

    ERIC Educational Resources Information Center

    Urhahne, Detlef; Nick, Sabine; Poepping, Anna Christin; Schulz , Sarah Jayne

    2013-01-01

    The present study examines the effects of different study tasks on the acquisition of knowledge about acids and bases in a computer-based learning environment. Three different task formats were selected to create three treatment conditions: learning with gap-fill and matching tasks, learning with multiple-choice tasks, and learning only from text…

  17. Problems and Possibilities of Web-Based Instruction: Transforming Social Studies Methods and Practice

    ERIC Educational Resources Information Center

    Riley, Karen L.; Stern, Barbara Slater

    2005-01-01

    In this article, the authors focus on the use of Web-based instruction in social studies methods courses. They examine in what ways Web-based instruction transforms both teaching and learning and explore the problems and possibilities involved with electronic classrooms, including Web-supported instruction. Their study is classroom…

  18. Faculty Adoption Behaviour about Web-Based Distance Education: A Case Study from China Agricultural University

    ERIC Educational Resources Information Center

    Li, Yan; Lindner, James R.

    2007-01-01

    The purpose of this study was to determine China Agricultural University's (CAU's) faculty adoption behaviour about web-based distance education (WBDE). Rogers' (2003) model of five stages in the innovation-decision process was adopted and modified as the theoretical base for the study. Quantitative research was employed and the research design…

  19. Predictors of Cerebral Palsy in Very Preterm Infants: The EPIPAGE Prospective Population-Based Cohort Study

    ERIC Educational Resources Information Center

    Beaino, Ghada; Khoshnood, Babak; Kaminski, Monique; Pierrat, Veronique; Marret, Stephane; Matis, Jacqueline; Ledesert, Bernard; Thiriez, Gerard; Fresson, Jeanne; Roze, Jean-Christophe; Zupan-Simunek, Veronique; Arnaud, Catherine; Burguet, Antoine; Larroque, Beatrice; Breart, Gerard; Ancel, Pierre-Yves

    2010-01-01

    Aim: The aim of this study was to assess the independent role of cerebral lesions on ultrasound scan, and several other neonatal and obstetric factors, as potential predictors of cerebral palsy (CP) in a large population-based cohort of very preterm infants. Method: As part of EPIPAGE, a population-based prospective cohort study, perinatal data…

  20. A Blended Learning Study on Implementing Video Recorded Speaking Tasks in Task-Based Classroom Instruction

    ERIC Educational Resources Information Center

    Kirkgoz, Yasemin

    2011-01-01

    This study investigates designing and implementing a speaking course in which face-to-face instruction informed by the principles of Task-Based Learning is blended with the use of technology, the video, for the first-year student teachers of English in Turkish higher education. The study consisted of three hours of task-based classroom…

  1. The Influence of Agenda-Based and Habitual Processes on Item Selection during Study

    ERIC Educational Resources Information Center

    Dunlosky, John; Ariel, Robert

    2011-01-01

    Research on study-time allocation has largely focused on agenda-based regulation, such as whether learners select items for study that are in their region of proximal learning. In 4 experiments, the authors evaluated the contribution of habitual responding to study-time allocation (e.g., reading from left to right). In Experiments 1 and 2,…

  2. A Study on Family-School Cooperation Based on an Analysis of School Documentation

    ERIC Educational Resources Information Center

    Polovina, Nada; Stanisic, Jelena

    2007-01-01

    Family-school cooperation is a very complex process that can be studied at different levels in a number of different ways. This study has covered only some aspects of cooperation between parents and teachers, based on school documentation of a Belgrade elementary school. The study covered analyses of 60 Attendance Registers pertaining to 60…

  3. Systematic review of couple-based HIV intervention and prevention studies: advantages, gaps, and future directions.

    PubMed

    Jiwatram-Negrón, Tina; El-Bassel, Nabila

    2014-10-01

    We conducted a systematic review of couple-based HIV biobehavioral (skills-building, VCT, and adherence) and biomedical (ART, circumcision) prevention and intervention studies designed to reduce sexual- and drug-risk behaviors and HIV transmission and acquisition. Of the 11,162 papers identified in the search, 93 peer-reviewed papers met the inclusion criteria and yielded a total of 33 studies conducted globally. Biobehavioral couple-based prevention and intervention studies have been efficacious in reducing sexual- and drug-risk behaviors, increasing access to HIV testing and care, and improving adherence. Biomedical couple-based studies were found to reduce HIV incidence among HIV-negative sex partners and viral load among HIV-positive partners. Despite much progress, couple-based HIV prevention and intervention studies remain limited; a number of methodological gaps exist and studies focusing on MSM, people who inject drugs, and sex workers are scarce.

  4. Systematic Review of Couple-Based HIV Intervention and Prevention Studies: Advantages, Gaps, and Future Directions

    PubMed Central

    El-Bassel, Nabila

    2015-01-01

    We conducted a systematic review of couple-based HIV biobehavioral (skills-building, VCT, and adherence) and biomedical (ART, circumcision) prevention and intervention studies designed to reduce sexual-and drug-risk behaviors and HIV transmission and acquisition. Of the 11,162 papers identified in the search, 93 peer-reviewed papers met the inclusion criteria and yielded a total of 33 studies conducted globally. Biobehavioral couple-based prevention and intervention studies have been efficacious in reducing sexual- and drug-risk behaviors, increasing access to HIV testing and care, and improving adherence. Biomedical couple-based studies were found to reduce HIV incidence among HIV-negative sex partners and viral load among HIV-positive partners. Despite much progress, couple-based HIV prevention and intervention studies remain limited; a number of methodological gaps exist and studies focusing on MSM, people who inject drugs, and sex workers are scarce. PMID:24980246

  5. The BELFRAIL (BFC80+) study: a population-based prospective cohort study of the very elderly in Belgium

    PubMed Central

    2010-01-01

    Background In coming decades the proportion of very elderly people living in the Western world will dramatically increase. This forthcoming "grey epidemic" will lead to an explosion of chronic diseases. In order to anticipate booming health care expenditures and to assure that social security is funded in the future, research focusing on the relationship between chronic diseases, frailty and disability is needed. The general aim of the BELFRAIL cohort study (BFC80+) is to study the dynamic interaction between health, frailty and disability in a multi-system approach focusing on cardiac dysfunction and chronic heart failure, lung function, sarcopenia, renal insufficiency and immunosenescence. Methods/Design The BFC80+ is a prospective, observational, population-based cohort study of subjects aged 80 years and older in three well-circumscribed areas of Belgium. In total, 29 general practitioner (GP) centres were asked to include patients aged 80 and older. Only three exclusion criteria were used: severe dementia, in palliative care and medical emergency. Two sampling methods for the recruitment of patients were used. Between November 2, 2008 and September 15, 2009, 567 subjects were included in the BFC80+ study. Every study participant was invited to undergo four study visits. The GP recorded background variables and medical history and performed a detailed anamnesis and clinical examination. The clinical research assistant performed an extensive examination including performance testing, questionnaires and technical examinations. Echocardiography was performed at home by a cardiologist. A blood sample was collected in the morning. Follow-up reporting of hard outcome measures including mortality, hospitalization and morbidity was organized. A second data collection is planned after 18 months. Discussion The BFC80+ was designed to acquire a better understanding of the epidemiology and pathophysiology of chronic diseases in the very elderly and to study the dynamic

  6. African American Advanced Placement chemistry students and their developing study habits: A phenomenologically-based interpretive study

    NASA Astrophysics Data System (ADS)

    Rasmussen, Natalie D.

    The academic achievement gap between African American and White students has gained much attention in recent years. Much has been written about the causes of and reasons for this problem ranging from the vestigial effects of slavery to poor parenting. Much less has been written or understood about its solution. While it is impossible for educators to change the pasts of their African American students, it is possible to effect change for the few minutes in which they are in direct contact with them each day. If African American science students are taught effective study skills and habits, then perhaps they might have the tools to close the achievement gap themselves. The participants in this phenomenologically based interpretive study were five African American Advanced Placement Chemistry students from an inner-city high school. Three in-depth interviews were conducted with each of the participants during the beginning, middle and end of a semester. The purpose of the interviews was to locate the students in terms of their thought processes, experiences and perceived barriers concerning the nature and practice of effective study and retention of chemistry content. The interviews were recorded and transcribed. The texts were then analyzed for common themes. Five common themes emerged from the interviews. These were: (1) Homework vs. Study: a distinction between homework---which students knew how to approach; and study---which they did not. (2) Student Effort: their changing perception of adequate and effective study practices while in a rigorous course. (3) Teacher Rigor: they perceived high expectations and challenging work as a sign of respect from their teachers. (4) Parental Involvement: students' admission that they desired more input from parents regarding their academic performance. (5) Racial Considerations: their need to disprove negative stereotypes and their personal observations regarding racial differences in studying. A discussion of the themes and

  7. Obesity Paradox and Recurrent Coronary Heart Disease in a Population-Based Study: Tehran Lipid and Glucose Study

    PubMed Central

    Asgari, Samaneh; Barzin, Maryam; Hosseinpanah, Farhad; Hadaegh, Farzad; Azizi, Fereidoun; Khalili, Davood

    2016-01-01

    Background Although current data shows a positive association between obesity and development of coronary heart disease (CHD) in general population, there is limited data on the important protective role of central or general obesity in patients with prevalent CHD or the “obesity paradox”, from this region. Objectives The objective of the present investigation was to describe the relationship between BMI categories and the recurrence of CHD in patients with a history of CHD using data from a large population-based study, the Tehran lipid and glucose study (TLGS). Patients and Methods The study was conducted on 440 adults, aged ≥ 30 years, with a history of CHD at baseline who attended the first (1999 - 2001) or second (2001 - 2003) phases of the Tehran Lipid and Glucose Study and had at least one year of follow-up until March 31, 2010. Cox proportional hazard models were used to evaluate the association among various BMI groups and recurrent CHD incidence. Results During a median follow-up of 8.44 years, 169 new cases of CHD occurred (incidence density of: 54.53 per 1000 person-years). The incidence of recurrent CHD was higher in the normal BMI compared with overweight and obese categories (68.71, 47.56 and 54.46 per 1000 person-years, respectively). In multivariable models, using the forward stepwise selection approach, compared to the overweight group (0.48 95% CI, 0.30-0.80), the obese group (0.55 95% CI, 0.28-1.06) lost its significant protective effect. Conclusions Results of this study demonstrated an apparently protective effect for overweight in comparison with normal weight against long-term recurrent CHD in patients with history of CHD.

  8. Data base dictionary for the Oak Ridge Reservation Hydrology and Geology Study Groundwater Data Base. Environmental Restoration Program

    SciTech Connect

    Thompson, B.K.

    1993-04-01

    The Oak Ridge Reservation Hydrology and Geology Study (ORRHAGS) Groundwater Data Base has been compiled to consolidate groundwater data from the three US Department of Energy facilities located on the Oak Ridge Reservation: the Oak Ridge K-25 Site, the Oak Ridge National Laboratory, and the Oak Ridge Y-12 Plant. Each of these facilities maintains its own groundwater and well construction data bases. Data were extracted from the existing data bases, converted to a consistent format, and integrated into the ORRHAGS Groundwater Data Base structures. This data base dictionary describes the data contained in the ORRHAGS Groundwater Data Base and contains information on data base structure, conventions, contents, and use.

  9. A Study of Basal Cell Carcinoma in South Asians for Risk Factor and Clinicopathological Characterization: A Hospital Based Study

    PubMed Central

    Mahajan, Bharat Bhushan; Kaur, Sandeep; Yadav, Ashish; Singh, Navtej; Singh, Amarbir

    2014-01-01

    Objectives. Although the incidence of skin cancers in India (part of South Asia) is low, the absolute number of cases may be significant due to large population. The existing literature on BCC in India is scant. So, this study was done focusing on its epidemiology, risk factors, and clinicopathological aspects. Methods. A hospital based cross-sectional study was conducted in Punjab, North India, from 2011 to 2013. History, examination and histopathological confirmation were done in all the patients visiting skin department with suspected lesions. Results. Out of 36 confirmed cases, 63.9% were females with mean ± SD age being 60.9 ± 14.2 years. Mean duration of disease was 4.7 years. Though there was statistically significant higher sun exposure in males compared to females (P value being 0.000), BCC was commoner in females, explainable by intermittent sun exposure (during household work in the open kitchens) in women. Majority of patients (88.9%) had a single lesion. Head and neck region was involved in 97.2% of cases, with nose being the commonest site (50%) with nodular/noduloulcerative morphology in 77.8% of cases. Pigmentation was evident in 22.2% of cases clinically. Nodular variety was the commonest histopathological variant (77.8%). Conclusions. This study highlights a paradoxically increasing trend of BCC with female preponderance, preferential involvement of nose, and higher percentage of pigmentation in Indians. PMID:25530883

  10. Exploring the acceptability and feasibility of conducting a large longitudinal population-based study in Canada.

    PubMed

    Kirkland, Susan A; Raina, Parminder S; Wolfson, Christina; Strople, Geoff; Kits, Olga; Dukeshire, Steven; Angus, Camille L; Szala-Meneok, Karen; Uniat, Jennifer; Keshavarz, Homa; Furlini, Linda; Pelletier, Amélie

    2009-09-01

    ABSTRACTSuccessful recruitment and retention for population-based longitudinal studies requires understanding facilitators and barriers to participation. This study explored Canadians' views regarding one such study, the proposed Canadian Longitudinal Study on Aging (CLSA). Focus groups of participants > or =40 years of age were held in six proposed CLSA data collection sites (Halifax, Montreal, Hamilton, Winnipeg, Calgary, and Vancouver) to discuss participating in a long-term study of healthy aging. There was fundamental support for longitudinal research on health and aging. Altruism was a key motivation to participation, and universities were viewed as credible parties to conduct such studies. Participants had few worries about providing biological samples but expressed concern about potential misuse of genetic materials, commercialization of participant data, and privacy issues. These findings have already informed current, and will inform future, work on the CLSA, and will also provide useful information to researchers who undertake other population-based longitudinal studies.

  11. Studies on some metal complexes of quinoxaline based unsymmetric ligand: Synthesis, spectral characterization, in vitro biological and molecular modeling studies.

    PubMed

    Dhanaraj, Chellaian Justin; Johnson, Jijo

    2016-08-01

    Mononuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes of an unsymmetric Schiff base ligand, 3-(-(3-(-3,5-dichloro-2-hydroxybenzylideneamino)propylimino)methyl)quinoxalin-2(1H) -one (L) were synthesized and characterized by various analytical and spectral techniques. The molar conductance values of metal complexes indicate non-electrolytic behavior of the metal complexes. The Schiff base act as tetra dentate ONNO donor ligand in Co(II), Ni(II), Zn(II) complexes and tridentate NNO donor in Cu(II) complex. Thermal stabilities of the newly synthesized compounds were determined by thermal analysis. Crystallinity, average grain size and unit cell parameters were determined from powder X-ray diffraction study. Electrochemical behaviors of the compounds were examined by cyclic voltammetry technique. The Schiff base and its complexes have been screened for their in vitro antimicrobial activities against some bacterial and fungal strains by disc diffusion method. The interaction of the compounds with calf thymus DNA (CT DNA) has been investigated by electronic absorption spectral titration and viscosity measurement (hydrodynamic) methods. Furthermore, the pUC18 DNA cleavage activities of the complexes have been explored. The compounds were also subjected to in vitro antioxidant, anticancer activity screening, druglikeness and bioactivity predictions using Molinspiration software. Molecular docking studies of the present compounds were carried out against B-DNA dodecamer d(CGCGAATTCGCG)2 and vascular endothelial growth factor receptor (VEGFR-2) kinase. Quantum chemical calculations were done with DFT method to determine the optimum geometry of the ligand and its metal complexes. From the quantum chemical parameters, the reactivity parameters of the compounds were established.

  12. Methods and background characteristics of the TOHNN study: a population-based study of oral health conditions in northern Norway

    PubMed Central

    Holde, Gro Eirin; Oscarson, Nils; Tillberg, Anders; Marstrander, Peter; Jönsson, Birgitta

    2016-01-01

    Objectives The aim of the Tromstannen – Oral Health in Northern Norway (TOHNN) study was to investigate oral health and dental-related diseases in an adult population. This article provides an overview of the background of the study and a description of the sample characteristics and methods employed in data collection. Study design Cross-sectional population-based study including a questionnaire and clinical dental examination. Methods A randomly selected sample of 2,909 individuals (20–79 years old) drawn from the population register was invited to participate in the study. The data were collected between October 2013 and November 2014 in Troms County in northern Norway. The questionnaire focused on oral health-related behaviours and attitudes, oral health-related quality of life, sense of coherence, dental anxiety and symptoms from the temporomandibular joint. The dental examinations, including radiographs, were conducted by 11 dental teams in 5 dental offices. The examination comprised of registration of dental caries, full mouth periodontal status, temporomandibular disorders, mucosal lesions and height and weight. The participants were grouped by age (20–34, 35–49, 50–64 and 65–79) and ethnicity (Norwegian, Sámi, other European and other world). Results From the original sample of 2,909 individuals, 1,986 (68.3%) people participated, of whom 1,019 (51.3%) were women. The highest attendance rate was among women 20–34 years old (80.3%) and the lowest in the oldest age group of women (55.4%). There was no difference in response rate between rural and urban areas. There was a positive correlation between population size and household gross income (p < 0.001) and education level (p < 0.001). The majority of Sámi resided in smaller municipalities. In larger cities, most participants used private dental health care services, whereas, in rural areas, most participants used the public dental health care service. Conclusion The TOHNN study has the

  13. Evaluating Work-Based Learning: Insights from an Illuminative Evaluation Study of Work-Based Learning in a Vocational Qualification

    ERIC Educational Resources Information Center

    van Rensburg, Estelle

    2008-01-01

    This article outlines an illuminative evaluation study of the work-based module in a vocational qualification in Animal Health offered for the paraveterinary industry by a distance education institution in South Africa. In illuminative evaluation, a programme is studied by qualitative methods to gain an in-depth understanding of its "instructional…

  14. Editorial--Avoiding Unethical Helicobacter pylori Clinical Trials: Susceptibility-Based Studies and Probiotics as Adjuvants.

    PubMed

    Graham, David Y

    2015-10-01

    As a general rule, any clinical study where the result is already known or when the investigator(s) compares an assigned treatment against another assigned treatment known to be ineffective in the study population (e.g., in a population with known clarithromycin resistance) is unethical. As susceptibility-based therapy will always be superior to empiric therapy in any population with a prevalence of antimicrobial resistance >0%, any trial that randomizes susceptibility-based therapy with empiric therapy would be unethical. The journal Helicobacter welcomes susceptibility or culture-guided studies, studies of new therapies, and studies of adjuvants and probiotics. However, the journal will not accept for review any study we judge to be lacking clinical equipoise or which assign subjects to a treatment known to be ineffective, such as a susceptibility-based clinical trial with an empiric therapy comparator. To assist authors, we provide examples and suggestions regarding trial design for comparative studies, for susceptibility-based studies, and for studies testing adjuvants or probiotics.

  15. Local Ancestry Inference in a Large US-Based Hispanic/Latino Study: Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

    PubMed Central

    Browning, Sharon R.; Grinde, Kelsey; Plantinga, Anna; Gogarten, Stephanie M.; Stilp, Adrienne M.; Kaplan, Robert C.; Avilés-Santa, M. Larissa; Browning, Brian L.; Laurie, Cathy C.

    2016-01-01

    We estimated local ancestry on the autosomes and X chromosome in a large US-based study of 12,793 Hispanic/Latino individuals using the RFMix method, and we compared different reference panels and approaches to local ancestry estimation on the X chromosome by means of Mendelian inconsistency rates as a proxy for accuracy. We developed a novel and straightforward approach to performing ancestry-specific PCA after finding artifactual behavior in the results from an existing approach. Using the ancestry-specific PCA, we found significant population structure within African, European, and Amerindian ancestries in the Hispanic/Latino individuals in our study. In the African ancestral component of the admixed individuals, individuals whose grandparents were from Central America clustered separately from individuals whose grandparents were from the Caribbean, and also from reference Yoruba and Mandenka West African individuals. In the European component, individuals whose grandparents were from Puerto Rico diverged partially from other background groups. In the Amerindian ancestral component, individuals clustered into multiple different groups depending on the grandparental country of origin. Therefore, local ancestry estimation provides further insight into the complex genetic structure of US Hispanic/Latino populations, which must be properly accounted for in genotype-phenotype association studies. It also provides a basis for admixture mapping and ancestry-specific allele frequency estimation, which are useful in the identification of risk factors for disease. PMID:27172203

  16. Local Ancestry Inference in a Large US-Based Hispanic/Latino Study: Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

    PubMed

    Browning, Sharon R; Grinde, Kelsey; Plantinga, Anna; Gogarten, Stephanie M; Stilp, Adrienne M; Kaplan, Robert C; Avilés-Santa, M Larissa; Browning, Brian L; Laurie, Cathy C

    2016-01-01

    We estimated local ancestry on the autosomes and X chromosome in a large US-based study of 12,793 Hispanic/Latino individuals using the RFMix method, and we compared different reference panels and approaches to local ancestry estimation on the X chromosome by means of Mendelian inconsistency rates as a proxy for accuracy. We developed a novel and straightforward approach to performing ancestry-specific PCA after finding artifactual behavior in the results from an existing approach. Using the ancestry-specific PCA, we found significant population structure within African, European, and Amerindian ancestries in the Hispanic/Latino individuals in our study. In the African ancestral component of the admixed individuals, individuals whose grandparents were from Central America clustered separately from individuals whose grandparents were from the Caribbean, and also from reference Yoruba and Mandenka West African individuals. In the European component, individuals whose grandparents were from Puerto Rico diverged partially from other background groups. In the Amerindian ancestral component, individuals clustered into multiple different groups depending on the grandparental country of origin. Therefore, local ancestry estimation provides further insight into the complex genetic structure of US Hispanic/Latino populations, which must be properly accounted for in genotype-phenotype association studies. It also provides a basis for admixture mapping and ancestry-specific allele frequency estimation, which are useful in the identification of risk factors for disease. PMID:27172203

  17. Preliminary Evaluation of a Field and Non-Field Based Social Studies Preservice Teacher Education Program

    ERIC Educational Resources Information Center

    Napier, John D.; Vansickle, Ronald L.

    1978-01-01

    Comparison of pre-service social studies teachers in field and non-field based methods courses indicated no significant differences with regard to teaching skills, attitudes, or behaviors teachers should exhibit in the classroom. (Author/DB)

  18. A Comparative Study of Structural and Process Quality in Center-Based and Family-Based Child Care Services

    ERIC Educational Resources Information Center

    Bigras, Nathalie; Bouchard, Caroline; Cantin, Gilles; Brunson, Liesette; Coutu, Sylvain; Lemay, Lise; Tremblay, Melissa; Japel, Christa; Charron, Annie

    2010-01-01

    This study seeks to determine whether center-based and family-based child care services differ with respect to process quality, as measured by the Educative Quality Observation Scales ("EQOS", Bourgon and Lavallee 2004a, b, c), for groups of children 18 months old and younger. It also seeks to identify structural variables associated with process…

  19. A Comparative Study of Problem-Based and Lecture-Based Learning in Junior Secondary School Science

    ERIC Educational Resources Information Center

    Wong, Kenson Kin Hang; Day, Jeffrey Richard

    2009-01-01

    The purpose of the study is to compare problem based learning (PBL) and lecture-based learning (LBL) in Hong Kong secondary students' science achievement. Secondary One students were divided into two groups: group A (n = 37), was taught two topics: "Human Reproduction" and "Density" through PBL; group B (n = 38) was taught the same topics by LBL.…

  20. Evaluation Study for an ISO 13606 Archetype Based Medical Data Visualization Method.

    PubMed

    Kopanitsa, Georgy

    2015-08-01

    The objective of this evaluation study is to assess a method for standard based medical data visualization. The method allows flexible and customizable visualization for ISO 13606 archetype based medical data. The chosen evaluation concept is based the Guideline for Good Evaluation Practice in Health Informatics (GEP-HI). The stages of the study were identified. Each stage got a detailed description. We also identified the participants and their required qualifications and responsibilities. The evaluation location was described in details. The evaluation metrics were defined. The questionnaires for doctors, patients and experts were developed to fulfill the requirements of the evaluation study. The study was performed in Tomsk, Russia. 30 patients and 5 doctors participated in the study. The overall performance of the users reached the expert level by the end of the study. Patients as well as medical staff stated in their comments that the usability of the system was high, and they preferred it to the previously used paper-based and computer based systems. This was also shown by the high level of satisfaction measured within our study. The visualization approach, integrated into the electronic health record, was well accepted in our pilot setting with high usability scores from patients and doctors alike. The results showed the efficiency for both modeling and visualization part of the system.

  1. Missing data in the exposure of interest and marginal structural models: a simulation study based on the Framingham Heart Study.

    PubMed

    Shortreed, Susan M; Forbes, Andrew B

    2010-02-20

    Missing data are common in longitudinal studies and can occur in the exposure interest. There has been little work assessing the impact of missing data in marginal structural models (MSMs), which are used to estimate the effect of an exposure history on an outcome when time-dependent confounding is present. We design a series of simulations based on the Framingham Heart Study data set to investigate the impact of missing data in the primary exposure of interest in a complex, realistic setting. We use a standard application of MSMs to estimate the causal odds ratio of a specific activity history on outcome. We report and discuss the results of four missing data methods, under seven possible missing data structures, including scenarios in which an unmeasured variable predicts missing information. In all missing data structures, we found that a complete case analysis, where all subjects with missing exposure data are removed from the analysis, provided the least bias. An analysis that censored individuals at the first occasion of missing exposure and includes a censorship model as well as a propensity model when creating the inverse probability weights also performed well. The presence of an unmeasured predictor of missing data only slightly increased bias, except in the situation such that the exposure had a large impact on missing data and the unmeasured variable had a large impact on missing data and outcome. A discussion of the results is provided using causal diagrams, showing the usefulness of drawing such diagrams before conducting an analysis. PMID:20025082

  2. Behavioural Comorbidity in Tanzanian Children with Epilepsy: A Community-Based Case-Control Study

    ERIC Educational Resources Information Center

    Burton, Kathryn; Rogathe, Jane; Hunter, Ewan; Burton, Matthew; Swai, Mark; Todd, Jim; Neville, Brian; Walker, Richard; Newton, Charles

    2011-01-01

    Aim: The aim of this study was to define the prevalence of and risk factors for behavioural disorders in children with epilepsy from a rural district of Tanzania by conducting a community-based case-control study. Method: One hundred and twelve children aged 6 to 14 years (55 males, 57 females; median age 12y) with active epilepsy (at least two…

  3. Analyzing Idioms and Their Frequency in Three Advanced ILI Textbooks: A Corpus-Based Study

    ERIC Educational Resources Information Center

    Alavi, Sepideh; Rajabpoor, Aboozar

    2015-01-01

    The present study aimed at identifying and quantifying the idioms used in three ILI "Advanced" level textbooks based on three different English corpora; MICASE, BNC and the Brown Corpus, and comparing the frequencies of the idioms across the three corpora. The first step of the study involved searching the books to find multi-word…

  4. Use of Scaffolding in Problem-Based Learning in an Elementary Classroom: A Case Study

    ERIC Educational Resources Information Center

    Dittmer, Lucinda

    2013-01-01

    The purpose of this qualitative study was to gather data on the scaffolding a facilitator developed and used for learners during a Problem-Based Learning (PBL) setting. The study explored how the learners developed their ability to share their understanding and current knowledge by solving the presented real-world problem through investigation…

  5. Effects of Problem-Based Learning on Attitude: A Meta-Analysis Study

    ERIC Educational Resources Information Center

    Demirel, Melek; Dagyar, Miray

    2016-01-01

    To date, researchers have frequently investigated students' attitudes toward courses supported by problem-based learning. There are several studies with different results in the literature. It is necessary to combine and interpret the findings of these studies through a meta-analysis method. This method aims to combine different results of similar…

  6. Computer-Based Materials: A Study of Learner Autonomy and Strategies

    ERIC Educational Resources Information Center

    Figura, Klaudia; Jarvis, Huw

    2007-01-01

    This paper reports on a study which examines the extent to which specified cognitive, social, and metacognitive strategies, are used by language students when working with computer-based materials (CBMs), in self-study contexts outside of the language classroom; particularly in a self-access centre (SAC). Data were collected using questionnaires,…

  7. Predicting Study Abroad Intentions Based on the Theory of Planned Behavior

    ERIC Educational Resources Information Center

    Schnusenberg, Oliver; de Jong, Pieter; Goel, Lakshmi

    2012-01-01

    The emphasis on study abroad programs is growing in the academic context as U.S. based universities seek to incorporate a global perspective in education. Using a model that has underpinnings in the theory of planned behavior (TPB), we predict students' intention to participate in short-term study abroad program. We use TPB to identify behavioral,…

  8. A Case Study: Problem-Based Learning for Civil Engineering Students in Transportation Courses

    ERIC Educational Resources Information Center

    Ahern, A. A.

    2010-01-01

    This paper describes two case studies where problem-based learning (PBL) has been introduced to undergraduate civil engineering students in University College Dublin. PBL has recently been put in place in the penultimate and final year transport engineering classes in the civil engineering degree in University College Dublin. In this case study,…

  9. The Study of Adopting Problem Based Learning in Normal Scale Class Course Design

    ERIC Educational Resources Information Center

    Hsu, Chia-ling

    2014-01-01

    This study adopts the Problem Based Learning (PBL) for pre-service teachers in teacher education program. The reasons to adopt PBL are the class scale is not a small class, the contents are too many to teach, and the technologies are ready to be used in classroom. This study used an intermediary, movie, for scenario to student to define the…

  10. The MORPG-Based Learning System for Multiple Courses: A Case Study on Computer Science Curriculum

    ERIC Educational Resources Information Center

    Liu, Kuo-Yu

    2015-01-01

    This study aimed at developing a Multiplayer Online Role Playing Game-based (MORPG) Learning system which enabled instructors to construct a game scenario and manage sharable and reusable learning content for multiple courses. It used the curriculum of "Introduction to Computer Science" as a study case to assess students' learning…

  11. Effectiveness Study of a CBT-Based Adolescent Coping with Depression Course

    ERIC Educational Resources Information Center

    Garvik, Margit; Idsoe, Thormod; Bru, Edvin

    2014-01-01

    Even though the efficacy of group-based cognitive behavioural interventions is well established both for adolescents diagnosed with major depressive disorders as well as for adolescents with depressive symptoms, in order to prevent further development, there has been a call for effectiveness studies in real world settings. This study investigated…

  12. The Study of Literature and Culture in a Web-Based Environment

    ERIC Educational Resources Information Center

    Katz, Yaacov; Rimon, Ofer

    2006-01-01

    The rationale behind the project is based on the belief that the study of a work of literature can effectively open a window of opportunity for pupils to study other countries' cultures and identities as well as contribute to pupils' own identity construction and to the understanding of the identity of others. Information and communication…

  13. State-Based Case Studies of Assessment Initiatives in Undergraduate Education: Chronology of Critical Points.

    ERIC Educational Resources Information Center

    Boyer, Carol M.; Ewell, Peter T.

    The Education Commission of the States (ECS) together with the American Association for Higher Education recently conducted five case studies of state-based approaches to assessment in undergraduate education in Colorado, Missouri, New Jersey, South Dakota, and Virginia. The case studies, in turn, are part of the Missouri Governor John Ashcroft's…

  14. An Integrated Competency-Based Approach to Management Education: An Italian MBA Case Study

    ERIC Educational Resources Information Center

    Camuffo, Arnaldo; Gerli, Fabrizio

    2004-01-01

    Several studies have analysed the impact of competency-based methodologies on human resource management, with special emphasis on their applications to management education and development. As concerns management education, however, these studies have usually focused on one or few separate aspects, never proposing a consistent application of…

  15. Efficiency Study of NLS Base-Year Design. RTI-22U-884-3.

    ERIC Educational Resources Information Center

    Moore, R. P.; And Others

    An efficiency study was conducted of the base year design used for the National Longitudinal Study of the High School Class of 1972 (NLS). Finding the optimal design involved a search for the numbers of sample schools and students that would maximize the variance at a given cost. Twenty-one variables describing students' plans, attitudes,…

  16. Sense of Community in a Blended Technology Integration Course: A Design-Based Research Study

    ERIC Educational Resources Information Center

    Harrison, J. Buckley; West, Richard E.

    2014-01-01

    This design-based research study explored whether "sense of community" was maintained while flexibility in the course was increased through an adoption of a unique blended learning model. Data collected in this study show a significant drop in the sense of connectedness score from a mean of 50.8 out of 66 to a mean of 39.68 in the first…

  17. A PARTICIPANT-BASED APPROACH TO INDOOR/OUTDOOR AIR MONITORING IN COMMUNITY HEALTH STUDIES

    EPA Science Inventory

    Community health studies of traffic-related air pollution have been hampered by the cost and participant burden associated with collecting household-level exposure data. The current study utilized a novel participant-based approach to collect indoor and outdoor air monitoring da...

  18. *A participant-based approach to indoor/outdoor air monitoring in Community Health Studies

    EPA Science Inventory

    Community health studies of traffic-related air pollution have been hampered by the cost and participant burden associated with collecting household-level exposure data. The current study utilized a participant-based approach to collect indoor and outdoor air monitoring data from...

  19. Contributions of Early Work-Based Learning: A Case Study of First Year Pharmacy Students

    ERIC Educational Resources Information Center

    Ting, Kang Nee; Wong, Kok Thong; Thang, Siew Ming

    2009-01-01

    Generally work-based learning opportunities are only offered to students in their penultimate year of undergraduate study. Little is known about the benefits and shortcomings of such experiential learning for students in the early stages of their undergraduate education. This is a mixed method study investigating first year undergraduate pharmacy…

  20. The Effect of Brain Based Learning on Academic Achievement: A Meta-Analytical Study

    ERIC Educational Resources Information Center

    Gozuyesil, Eda; Dikici, Ayhan

    2014-01-01

    This study's aim is to measure the effect sizes of the quantitative studies that examined the effectiveness of brain-based learning on students' academic achievement and to examine with the meta-analytical method if there is a significant difference in effect in terms of the factors of education level, subject matter, sampling size, and…

  1. A Qualitative Study about Performance Based Assesment Methods Used in Information Technologies Lesson

    ERIC Educational Resources Information Center

    Daghan, Gökhan; Akkoyunlu, Buket

    2014-01-01

    In this study, Information Technologies teachers' views and usage cases on performance based assesment methods (PBAMs) are examined. It is aimed to find out which of the PBAMs are used frequently or not used, preference reasons of these methods and opinions about the applicability of them. Study is designed with the phenomenological design…

  2. Social marketing-based communications to integrate and support the HEALTHY study intervention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The HEALTHY study was a randomized, controlled, multicenter, middle school-based, multifaceted intervention designed to reduce risk factors for the development of type 2 diabetes. The study randomized 42 middle schools to intervention or control, and followed students from the sixth to the eighth gr...

  3. Effect of Computer-Based Video Games on Children: An Experimental Study

    ERIC Educational Resources Information Center

    Chuang, Tsung-Yen; Chen, Wei-Fan

    2009-01-01

    This experimental study investigated whether computer-based video games facilitate children's cognitive learning. In comparison to traditional computer-assisted instruction (CAI), this study explored the impact of the varied types of instructional delivery strategies on children's learning achievement. One major research null hypothesis was…

  4. Is "Learning by Doing" Important? A Study of Doing-Based Learning

    ERIC Educational Resources Information Center

    Moye, Johnny J.; Dugger, William E., Jr.; Starkweather, Kendall N.

    2014-01-01

    This is the second in a series of articles discussing the "Doing-Based Learning" study. The purpose of this study is to determine the extent to which U.S. public school elementary and secondary education science, technology, engineering, and mathematics (STEM) students are doing activities in their classrooms. The first article (Moye,…

  5. Project-Based Learning (PBL) in Science and Technology: A Case Study of Professional Development.

    ERIC Educational Resources Information Center

    Rosenfeld, Sherman; Ben-Hur, Yehuda

    This case study focuses on one approach to the professional development of science and technology with regard to Project-Based Learning (PBL). Sections include: (1) rationale and goals; (2) context, population, and methods of study; (3) content and sequence of the PBL workshop; (4) teacher projects; and (5) phenomena of note. Among the conclusions…

  6. Asthma and Attention-Deficit/Hyperactivity Disorder: A Nationwide Population-Based Prospective Cohort Study

    ERIC Educational Resources Information Center

    Chen, Mu-Hong; Su, Tung-Ping; Chen, Ying-Sheue; Hsu, Ju-Wei; Huang, Kai-Lin; Chang, Wen-Han; Chen, Tzeng-Ji; Bai, Ya-Mei

    2013-01-01

    Background: Previous cross-sectional studies have suggested an association between asthma and attention-deficit/hyperactivity disorder (ADHD), but the temporal relationship was not determined. Using a nationwide population-based prospective case-control cohort study (1:4, age-/gender-matched), we hypothesized that asthma in infanthood or early…

  7. Operationalizing Levels of Academic Mastery Based on Vygotsky's Theory: The Study of Mathematical Knowledge

    ERIC Educational Resources Information Center

    Nezhnov, Peter; Kardanova, Elena; Vasilyeva, Marina; Ludlow, Larry

    2015-01-01

    The present study tested the possibility of operationalizing levels of knowledge acquisition based on Vygotsky's theory of cognitive growth. An assessment tool (SAM-Math) was developed to capture a hypothesized hierarchical structure of mathematical knowledge consisting of procedural, conceptual, and functional levels. In Study 1, SAM-Math was…

  8. A Study on M2M-based System for Hygienic Meteorology Service

    NASA Astrophysics Data System (ADS)

    Song, Jae-Gu; Ahn, Jae Young; Kim, Seoksoo

    M2M proposes a standardized communications technology between network and devices. This study has designed an M2M-based system to smoothly deliver information between devices which were required to provide hygienic meteorology services. Especially, an efficient plan for service provision has been studied, by classifying the types of information at each stage of user, EM, SM, HSM and SPM.

  9. School-Community Partnerships and Community-Based Education: A Case Study of a Novice Program

    ERIC Educational Resources Information Center

    Cole, Anna Gahl

    2010-01-01

    This case study examines the struggles and successes of teachers and students collaborating with community organizations on the Second Tuesday Project, a community-based research and service program at an urban high school. Using qualitative methods, the study includes data from interviews, participant-observations, and focus groups to describe…

  10. Lessons Learned in Conducting a Lottery-Based Study of Core Knowledge Charter Schools

    ERIC Educational Resources Information Center

    White, Thomas G.; Grissmer, David W.; Altenhofen, Shannon; Larson, Jennifer

    2013-01-01

    The authors are presently in the fourth year of a six-year, lottery-based randomized control trial (RCT) studying the effectiveness of nine Colorado charter schools that have implemented Core Knowledge®. Core Knowledge (CK) is a comprehensive K-8 curriculum for language arts, math, science, social studies, visual arts, and music that is intended…

  11. Neural Correlates of Communication Skill and Symptom Severity in Autism: A Voxel-Based Morphometry Study

    ERIC Educational Resources Information Center

    Parks, Lauren K.; Hill, Dina E.; Thoma, Robert J.; Euler, Matthew J.; Lewine, Jeffrey D.; Yeo, Ronald A.

    2009-01-01

    Although many studies have compared the brains of normal controls and individuals with autism, especially older, higher-functioning individuals with autism, little is known of the neural correlates of the vast clinical heterogeneity characteristic of the disorder. In this study, we used voxel-based morphometry (VBM) to examine gray matter…

  12. Effects of an Internet-Based Voucher Reinforcement Program for Smoking Abstinence: A Feasibility Study

    ERIC Educational Resources Information Center

    Dallery, Jesse; Glenn, Irene M.

    2005-01-01

    The present study tested the feasibility of an Internet-based method to obtain objective evidence of smoking abstinence and to deliver vouchers for evidence of abstinence. Four heavy smokers participated in this 4-week study. Twice daily, participants made video recordings of themselves providing a breath carbon monoxide (CO) sample with a Web…

  13. A Quantitative Comparative Study Measuring Consumer Satisfaction Based on Health Record Format

    ERIC Educational Resources Information Center

    Moore, Vivianne E.

    2013-01-01

    This research study used a quantitative comparative method to investigate the relationship between consumer satisfaction and communication based on the format of health record. The central problem investigated in this research study related to the format of health record used and consumer satisfaction with care provided and effect on communication…

  14. Evaluating the Effectiveness of Community-Based Dementia Care Networks: The Dementia Care Networks' Study

    ERIC Educational Resources Information Center

    Lemieux-Charles, Louis; Chambers, Larry W.; Cockerill, Rhonda; Jaglal, Susan; Brazil, Kevin; Cohen, Carole; LeClair, Ken; Dalziel, Bill; Schulman, Barbara

    2005-01-01

    Purpose: The Dementia Care Networks' Study examined the effectiveness of four community-based, not-for-profit dementia networks. The study involved assessing the relationship between the types of administrative and service-delivery exchanges that occurred among the networked agencies and the network members' perception of the effectiveness of…

  15. A Longitudinal Investigation of Project-Based Instruction and Student Achievement in High School Social Studies

    ERIC Educational Resources Information Center

    Summers, Emily J.; Dickinson, Gail

    2012-01-01

    This longitudinal study focused on how project-based instruction (PBI) influenced secondary social studies students' academic achievement and promoted College and Career Readiness (CCR). We explored and compared student achievement in a PBI high school versus a traditional instruction high school within the same rural school district. While…

  16. A Population-Based Longitudinal Study of Depression in Children with Developmental Disabilities in Manitoba

    ERIC Educational Resources Information Center

    Shooshtari, Shahin; Brownell, Marni; Dik, Natalia; Chateau, Dan; Yu, C. T.; Mills, Rosemary S. L.; Burchill, Charles A.; Wetzel, Monika

    2014-01-01

    In this population-based study, prevalence of depression was estimated and compared between children with and without developmental disability (DD). Twelve years of administrative data were linked to identify a cohort of children with DD living in the Canadian province of Manitoba. Children in the study cohort were matched with children without DD…

  17. Understanding Angle and Angle Measure: A Design-Based Research Study Using Context Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2015-01-01

    Mobile technologies are quickly becoming tools found in the educational environment. The researchers in this study use a form of mobile learning to support students in learning about angle concepts. Design-based research is used in this study to develop an empirically-substantiated local instruction theory about students' develop of angle and…

  18. Parent Perspective on the Home-Based Interim Alternative Educational Setting: A Phenomenological Study

    ERIC Educational Resources Information Center

    Jones, Gregory L.

    2011-01-01

    The purpose of this study was to explore and describe the perspectives of parents of expelled disabled students placed in home-based interim alternative educational settings (IAES). The study consisted of three parent participants whose disabled children, by virtue of their violations of the school district's discipline policy, were…

  19. Making pharmacogenomic-based prescribing alerts more effective: A scenario-based pilot study with physicians.

    PubMed

    Overby, Casey Lynnette; Devine, Emily Beth; Abernethy, Neil; McCune, Jeannine S; Tarczy-Hornoch, Peter

    2015-06-01

    To facilitate personalized drug dosing (PDD), this pilot study explored the communication effectiveness and clinical impact of using a prototype clinical decision support (CDS) system embedded in an electronic health record (EHR) to deliver pharmacogenomic (PGx) information to physicians. We employed a conceptual framework and measurement model to access the impact of physician characteristics (previous experience, awareness, relative advantage, perceived usefulness), technology characteristics (methods of implementation-semi-active/active, actionability-low/high) and a task characteristic (drug prescribed) on communication effectiveness (usefulness, confidence in prescribing decision), and clinical impact (uptake, prescribing intent, change in drug dosing). Physicians performed prescribing tasks using five simulated clinical case scenarios, presented in random order within the prototype PGx-CDS system. Twenty-two physicians completed the study. The proportion of physicians that saw a relative advantage to using PGx-CDS was 83% at the start and 94% at the conclusion of our study. Physicians used semi-active alerts 74-88% of the time. There was no association between previous experience with, awareness of, and belief in a relative advantage of using PGx-CDS and improved uptake. The proportion of physicians reporting confidence in their prescribing decisions decreased significantly after using the prototype PGx-CDS system (p=0.02). Despite decreases in confidence, physicians perceived a relative advantage to using PGx-CDS, viewed semi-active alerts on most occasions, and more frequently changed doses toward doses supported by published evidence. Specifically, sixty-five percent of physicians reduced their dosing, significantly for capecitabine (p=0.002) and mercaptopurine/thioguanine (p=0.03). These findings suggest a need to improve our prototype such that PGx CDS content is more useful and delivered in a way that improves physician's confidence in their prescribing

  20. An Empirical Study of Instructor Adoption of Web-Based Learning Systems

    ERIC Educational Resources Information Center

    Wang, Wei-Tsong; Wang, Chun-Chieh

    2009-01-01

    For years, web-based learning systems have been widely employed in both educational and non-educational institutions. Although web-based learning systems are emerging as a useful tool for facilitating teaching and learning activities, the number of users is not increasing as fast as expected. This study develops an integrated model of instructor…

  1. Education Longitudinal Study of 2002: Base Year Data File User's Manual. NCES 2004-405

    ERIC Educational Resources Information Center

    Ingels, Steven J.; Pratt, Daniel J.; Rogers, James E.; Siegel, Peter H.; Stutts, Ellen S.

    2004-01-01

    This manual has been produced to familiarize data users with the procedures followed for data collection and processing for the base year of the Education Longitudinal Study of 2002 (ELS:2002). It also provides the necessary documentation for use of the public-use data files, as they appear on the ELS:2002 base year Electronic Codebook (ECB). Most…

  2. A Phenomenographical Study of the Enlighten Foundation Learning Program for Faith-Based Women

    ERIC Educational Resources Information Center

    Griffith, Anne Higginbotham

    2011-01-01

    The purpose of this study is to investigate and chart the qualitatively different ways Christian faith-based women make meaning of and understand the learning intervention of The Enlighten Foundation's Learning Program. Research supports the use of an interactive, experienced-based learning program as conducive to developmental change for women.…

  3. Video-Based Multimedia Designs: A Research Study Testing Learning Effectiveness

    ERIC Educational Resources Information Center

    Reiss, David

    2007-01-01

    This paper summarizes research conducted on three computer based video models' effectiveness for learning based on memory and comprehension. In this quantitative study, a two-minute video presentation was created and played back in three different types of media players, for a sample of eighty-seven college freshman. The three players evaluated…

  4. Self-Regulation in a Web-Based Course: A Case Study

    ERIC Educational Resources Information Center

    Whipp, Joan L.; Chiarelli, Stephannie

    2004-01-01

    Little is known about how successful students in Web-based courses self-regulate their learning. This descriptive case study used a social cognitive model of self-regulated learning (SRL) to investigate how six graduate students used and adapted traditional SRL strategies to complete tasks and cope with challenges in a Web-based technology course;…

  5. School-Based Mentoring: A Study of Volunteer Motivations and Benefits

    ERIC Educational Resources Information Center

    Caldarella, Paul; Gomm, Robert Jeff; Shatzer, Ryan H.; Wall, D. Gary

    2010-01-01

    While research has been conducted concerning the effects of school-based mentoring on at risk students, limited work has focused on the volunteer mentors. This study examined the motivations of adult volunteers and the benefits of their participation in a six-month, school-based mentoring program. A total of 31 volunteers completed adapted…

  6. School-Based Mentoring: A Study of Volunteer Motivations and Benefits

    ERIC Educational Resources Information Center

    Caldarella, Paul; Gomm, Robert J.; Shatzer, Ryan H.; Wall, D. Gary

    2010-01-01

    While research has been conducted concerning the effects of school-based mentoring on at-risk students, limited work has focused on the volunteer mentors. This study examined the motivations of adult volunteers and the benefits of their participation in a six-month, school-based mentoring program. A total of 31 volunteers completed adapted…

  7. Identifying "E-mmediacy" Strategies for Web-Based Instruction: A Delphi Study

    ERIC Educational Resources Information Center

    Slagter van Tryon, Patricia J.; Bishop, M. J.

    2006-01-01

    Despite the continued growth of Web-based courses, and the great promise of anytime, any place learning, it appears that Web-based instruction fails to produce the sense of "social connectedness" often highly valued in face-to-face instruction. The purpose of this study was to identify problems instructors face that impede social connectedness…

  8. A Comparative Study of French and Turkish Students' Ideas on Acid-Base Reactions

    ERIC Educational Resources Information Center

    Cokelez, Aytekin

    2010-01-01

    The goal of this comparative study was to determine the knowledge that French and Turkish upper secondary-school students (grades 11 and 12) acquire on the concept of acid-base reactions. Following an examination of the relevant curricula and textbooks in the two countries, 528 students answered six written questions about the acid-base concept.…

  9. Evaluation Criteria for Competency-Based Syllabi: A Chilean Case Study Applying Mixed Methods

    ERIC Educational Resources Information Center

    Jerez, Oscar; Valenzuela, Leslier; Pizarro, Veronica; Hasbun, Beatriz; Valenzuela, Gabriela; Orsini, Cesar

    2016-01-01

    In recent decades, higher education institutions worldwide have been moving from knowledge-based to competence-based curricula. One of the greatest challenges in this transition is the difficulty in changing the knowledge-oriented practices of teachers. This study evaluates the consistency between syllabus design and the requirements imposed by a…

  10. Overcoming the Barriers to Uptake: A Study of 6 Danish Health-Based Serious Games Projects

    ERIC Educational Resources Information Center

    Brown, Damian

    2013-01-01

    Serious gaming for health benefits is moving out of the realm of being potentially interesting, and the authors are starting to see a growing maturity in the field. This study of six serious gaming projects based either wholly or partly in Denmark investigates the changes taking place in the healthcare area based on experiences with serious gaming…

  11. National Longitudinal Study of the High School Class of 1972: Critical Data Base. 22U-884.

    ERIC Educational Resources Information Center

    Talbert, Robin

    The National Longitudinal Study of the High School Class of 1972 (NLS) critical data base contains 151 items (plus background information) from the base year and followup questionnaires; about thirty-seven percent of all items. This set of critical items consists of: (1) basic demographic variables; (2) items necessary for defining activity states…

  12. The Effects of Team-Based Learning on Social Studies Knowledge Acquisition in High School

    ERIC Educational Resources Information Center

    Wanzek, Jeanne; Vaughn, Sharon; Kent, Shawn C.; Swanson, Elizabeth A.; Roberts, Greg; Haynes, Martha; Fall, Anna-Mária; Stillman-Spisak, Stephanie J.; Solis, Michael

    2014-01-01

    This randomized control trial examined the efficacy of team-based learning implemented within 11th-grade social studies classes. A randomized blocked design was implemented with 26 classes randomly assigned to treatment or comparison. In the treatment classes teachers implemented team-based learning practices to support students in engaging in…

  13. Transforming Classrooms through Game-Based Learning: A Feasibility Study in a Developing Country

    ERIC Educational Resources Information Center

    Vate-U-Lan, Poonsri

    2015-01-01

    This article reports an exploratory study which investigated attitudes towards the practice of game-based learning in teaching STEM (science, technology, engineering and mathematics) within a Thai educational context. This self-administered Internet-based survey yielded 169 responses from a snowball sampling technique. Three fifths of respondents…

  14. Model of Values-Based Management Process in Schools: A Mixed Design Study

    ERIC Educational Resources Information Center

    Dogan, Soner

    2016-01-01

    The aim of this paper is to evaluate the school administrators' values-based management behaviours according to the teachers' perceptions and opinions and, accordingly, to build a model of values-based management process in schools. The study was conducted using explanatory design which is inclusive of both quantitative and qualitative methods.…

  15. Challenge Study: A Project-Based Learning on a Wireless Communication System at Technical High School

    ERIC Educational Resources Information Center

    Terasawa, Ikuo

    2016-01-01

    The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system. The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.…

  16. Distinguishing Themes of Cultural Responsiveness: A Study of Document-Based Learning

    ERIC Educational Resources Information Center

    Swartz, Ellen E.

    2012-01-01

    This qualitative study examines the distinguishing themes of cultural responsiveness in state- and federally-derived document-based learning materials. Two data sources--"Teaching with Documents" articles in Social Education and Document Based Questions on New York State 11th-grade U.S. History and Government Regents exams--were examined using…

  17. The Place of Community-Based Learning in Higher Education: A Case Study of Interchange

    ERIC Educational Resources Information Center

    Hardwick, Louise

    2013-01-01

    This article focuses on one strand of community engagement: community-based learning for students. It considers in particular Interchange as a case study. Interchange is a registered charity based in, but independent of, a department in a Higher Education Institution. It brokers between undergraduate research/work projects and Voluntary Community…

  18. Conducting Rigorous Survey Research in the Study of School-Based Consultation

    ERIC Educational Resources Information Center

    Hazel, Cynthia E.; Newman, Daniel S.; Barrett, Courtenay A.

    2016-01-01

    The evidence base for school-based consultation practice and training is limited by a small number of studies, possibly due to unique challenges in researching consultation. For example, there are myriad variables to measure and idiosyncratic cultural and contextual factors to account for when investigating what works, for whom, and in what…

  19. Can Interactive Web-Based CAD Tools Improve the Learning of Engineering Drawing? A Case Study

    ERIC Educational Resources Information Center

    Pando Cerra, Pablo; Suárez González, Jesús M.; Busto Parra, Bernardo; Rodríguez Ortiz, Diana; Álvarez Peñín, Pedro I.

    2014-01-01

    Many current Web-based learning environments facilitate the theoretical teaching of a subject but this may not be sufficient for those disciplines that require a significant use of graphic mechanisms to resolve problems. This research study looks at the use of an environment that can help students learn engineering drawing with Web-based CAD…

  20. Assessing the Impact of a Race-Based Course on Counseling Students: A Quantitative Study

    ERIC Educational Resources Information Center

    Paone, Tina R.; Malott, Krista M.; Barr, Jason J.

    2015-01-01

    This study sought to determine changes in 121 White counseling students following their participation in an experiential, race-based course taught in a group format. Pre- and postoutcomes were reported based on instruments that measured White racial identity development, White privilege, color blindness, and the costs of racism. Findings indicated…

  1. Performance-Based Service Quality Model: An Empirical Study on Japanese Universities

    ERIC Educational Resources Information Center

    Sultan, Parves; Wong, Ho

    2010-01-01

    Purpose: This paper aims to develop and empirically test the performance-based higher education service quality model. Design/methodology/approach: The study develops 67-item instrument for measuring performance-based service quality with a particular focus on the higher education sector. Scale reliability is confirmed using the Cronbach's alpha.…

  2. A Descriptive Study of a Building-Based Team Problem-Solving Process

    ERIC Educational Resources Information Center

    Brewer, Alexander B.

    2010-01-01

    The purpose of this study was to empirically evaluate Building-Based Teams for General Education Intervention or BBT for GEI. BBT for GEI is a team problem-solving process designed to assist schools in conducting research-based interventions in the general education setting. Problem-solving teams are part of general education and provide support…

  3. Enriching Project-Based Learning Environments with Virtual Manipulatives: A Comparative Study

    ERIC Educational Resources Information Center

    Çakiroglu, Ünal

    2014-01-01

    Problem statement: Although there is agreement on the potential of project based learning (PBL) and virtual manipulatives (VMs), their positive impact depends on how they are used. This study was based on supporting the use of online PBL environments and improving the efficacy of the instructional practices in PBL by combining the potentials of…

  4. "Development of Model-Based Air Pollution Exposure Metrics for use in Epidemiologic Studies"

    EPA Science Inventory

    Population-based epidemiological studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available concentrations from central monitoring sites. U.S. EPA in collaboration w...

  5. DEVELOPMENT OF MODEL-BASED AIR POLLUTION EXPOSURE METRICS FOR USE IN EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    Population-based epidemiological studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available concentrations from central monitoring sites. U.S. EPA in collaboration w...

  6. Task Complexity, Focus on L2 Constructions, and Individual Differences: A Classroom-Based Study

    ERIC Educational Resources Information Center

    Revesz, Andrea

    2011-01-01

    Motivated by cognitive-interactionist frameworks for task-based learning, this study explores whether task complexity affects the extent to which learners focus on form-meaning connections during task-based work in a classroom setting, and whether this relationship is modulated by 3 individual difference factors--linguistic self-confidence,…

  7. Enhancing Reading Comprehension through Task-Based Writing Activities: An Experimental Study

    ERIC Educational Resources Information Center

    Tilfarlioglu, Filiz Yalcin; Basaran, Suleyman

    2007-01-01

    Task-based learning is a popular topic in ELT/EFL circles nowadays. It is accepted by its proponents as a flourishing method that may replace Communicative Language Learning. However, it can also be seen as an adventure just because there are almost no experimental studies to tackle questions concerning applicability of Task-based Learning. In…

  8. Multiculturalism in Technology-Based Education: Case Studies on ICT-Supported Approaches

    ERIC Educational Resources Information Center

    Garcia-Penalvo, Francicso Jose

    2013-01-01

    Our differences in language, cultures, and history around the world play a vital role in the way we learn. As technology-based education continues to be used worldwide, there is an ever growing interest in how multiculturalism comes into effect. Multiculturalism in Technology-Based Education: Case Studies on ICT-Supported Approaches explores the…

  9. Assessment Criteria for Competency-Based Education: A Study in Nursing Education

    ERIC Educational Resources Information Center

    Fastré, Greet M. J.; van der Klink, Marcel R.; Amsing-Smit, Pauline; van Merriënboer, Jeroen J.

    2014-01-01

    This study examined the effects of type of assessment criteria (performance-based vs. competency-based), the relevance of assessment criteria (relevant criteria vs. all criteria), and their interaction on secondary vocational education students' performance and assessment skills. Students on three programmes in the domain of nursing and care…

  10. Facilitating Teachers' Participation in School-Based Health Promotion--A Qualitative Study

    ERIC Educational Resources Information Center

    Viig, Nina Grieg; Wold, Bente

    2005-01-01

    The focus of this article is on examining Norwegian teachers' perception of what factors at the school's organisational level have facilitated their participation in a school-based health promotion project. The study is based on 12 semistructured interviews with teachers from two of the pilot schools participating in the European Network of Health…

  11. Numerical Study on the Flow Mechanism of Base Aerodynamic Force Acting on the Vertical Landing Rocket

    NASA Astrophysics Data System (ADS)

    Fujimatsu, Nobuyoshi; Suzuki, Kojiro

    The base flow field of a vertical landing rocket in ground effect is numerically studied to clarify the mechanism of downward force acting on the body. Two characteristic patterns in the pressure distribution on the base surface are successfully captured as observed in the experiments. When the distance between the base and the ground surface is small, vorticies generated in the shear layer of the jet boundary interact with both the ground and base surfaces. The base pressure near the axis of the base is significantly reduced and large downward force appears due to vortical structure in the base region. When the distance is large, the vorticies are convected along the ground surface and the base pressure near the edge of the vehicle base is reduced due to suction of the ambient air. The numerical results indicate that unsteady motion of such vortices plays an important role in formation of the flow patterns described above.

  12. Association between recruitment methods and attrition in Internet-based studies.

    PubMed

    Bajardi, Paolo; Paolotti, Daniela; Vespignani, Alessandro; Eames, Ken; Funk, Sebastian; Edmunds, W John; Turbelin, Clement; Debin, Marion; Colizza, Vittoria; Smallenburg, Ronald; Koppeschaar, Carl; Franco, Ana O; Faustino, Vitor; Carnahan, AnnaSara; Rehn, Moa; Merletti, Franco; Douwes, Jeroen; Firestone, Ridvan; Richiardi, Lorenzo

    2014-01-01

    Internet-based systems for epidemiological studies have advantages over traditional approaches as they can potentially recruit and monitor a wider range of individuals in a relatively inexpensive fashion. We studied the association between communication strategies used for recruitment (offline, online, face-to-face) and follow-up participation in nine Internet-based cohorts: the Influenzanet network of platforms for influenza surveillance which includes seven cohorts in seven different European countries, the Italian birth cohort Ninfea and the New Zealand birth cohort ELF. Follow-up participation varied from 43% to 89% depending on the cohort. Although there were heterogeneities among studies, participants who became aware of the study through an online communication campaign compared with those through traditional offline media seemed to have a lower follow-up participation in 8 out of 9 cohorts. There were no clear differences in participation between participants enrolled face-to-face and those enrolled through other offline strategies. An Internet-based campaign for Internet-based epidemiological studies seems to be less effective than an offline one in enrolling volunteers who keep participating in follow-up questionnaires. This suggests that even for Internet-based epidemiological studies an offline enrollment campaign would be helpful in order to achieve a higher participation proportion and limit the cohort attrition.

  13. Association between Recruitment Methods and Attrition in Internet-Based Studies

    PubMed Central

    Bajardi, Paolo; Paolotti, Daniela; Vespignani, Alessandro; Eames, Ken; Funk, Sebastian; Edmunds, W. John; Turbelin, Clement; Debin, Marion; Colizza, Vittoria; Smallenburg, Ronald; Koppeschaar, Carl; Franco, Ana O.; Faustino, Vitor; Carnahan, AnnaSara; Rehn, Moa; Merletti, Franco; Douwes, Jeroen; Firestone, Ridvan; Richiardi, Lorenzo

    2014-01-01

    Internet-based systems for epidemiological studies have advantages over traditional approaches as they can potentially recruit and monitor a wider range of individuals in a relatively inexpensive fashion. We studied the association between communication strategies used for recruitment (offline, online, face-to-face) and follow-up participation in nine Internet-based cohorts: the Influenzanet network of platforms for influenza surveillance which includes seven cohorts in seven different European countries, the Italian birth cohort Ninfea and the New Zealand birth cohort ELF. Follow-up participation varied from 43% to 89% depending on the cohort. Although there were heterogeneities among studies, participants who became aware of the study through an online communication campaign compared with those through traditional offline media seemed to have a lower follow-up participation in 8 out of 9 cohorts. There were no clear differences in participation between participants enrolled face-to-face and those enrolled through other offline strategies. An Internet-based campaign for Internet-based epidemiological studies seems to be less effective than an offline one in enrolling volunteers who keep participating in follow-up questionnaires. This suggests that even for Internet-based epidemiological studies an offline enrollment campaign would be helpful in order to achieve a higher participation proportion and limit the cohort attrition. PMID:25490045

  14. Association between recruitment methods and attrition in Internet-based studies.

    PubMed

    Bajardi, Paolo; Paolotti, Daniela; Vespignani, Alessandro; Eames, Ken; Funk, Sebastian; Edmunds, W John; Turbelin, Clement; Debin, Marion; Colizza, Vittoria; Smallenburg, Ronald; Koppeschaar, Carl; Franco, Ana O; Faustino, Vitor; Carnahan, AnnaSara; Rehn, Moa; Merletti, Franco; Douwes, Jeroen; Firestone, Ridvan; Richiardi, Lorenzo

    2014-01-01

    Internet-based systems for epidemiological studies have advantages over traditional approaches as they can potentially recruit and monitor a wider range of individuals in a relatively inexpensive fashion. We studied the association between communication strategies used for recruitment (offline, online, face-to-face) and follow-up participation in nine Internet-based cohorts: the Influenzanet network of platforms for influenza surveillance which includes seven cohorts in seven different European countries, the Italian birth cohort Ninfea and the New Zealand birth cohort ELF. Follow-up participation varied from 43% to 89% depending on the cohort. Although there were heterogeneities among studies, participants who became aware of the study through an online communication campaign compared with those through traditional offline media seemed to have a lower follow-up participation in 8 out of 9 cohorts. There were no clear differences in participation between participants enrolled face-to-face and those enrolled through other offline strategies. An Internet-based campaign for Internet-based epidemiological studies seems to be less effective than an offline one in enrolling volunteers who keep participating in follow-up questionnaires. This suggests that even for Internet-based epidemiological studies an offline enrollment campaign would be helpful in order to achieve a higher participation proportion and limit the cohort attrition. PMID:25490045

  15. Study on the methodology of developing evidence-based clinical practice guidelines of Chinese medicine.

    PubMed

    Chen, Zheng-guang; Luo, Hui; Xu, Shan; Yang, Yan; Wang, Shou-chuan

    2015-11-01

    At present, evidence-based clinical practice guideline (EBCPG) is the main mode of developing clinical practice guidelines (CPGs) in the world, but in China, most of CPGs of Chinese medicine (CM) are still guidelines based on expert consensus. The objective of this study is to construct initially the methodology of developing EBCPGs of CM and to promote the development of standardization of CM. Based on the development of "Guideline for Diagnosis and Treatment of Common Pediatric Diseases in CM", the methodology of developing EBCPG of CM was explored by analyzing the pertinent literature and considering the characteristics of CM. In this study, the key problem was to put forward the suggestion and strategies. However, due to the methodology study of developing EBCPG of CM is still in the initial stage, there are still some problems which need further study.

  16. “Smallball” evaluation: a prescription for studying community-based information interventions*

    PubMed Central

    Friedman, Charles P.

    2005-01-01

    Objectives: This paper argues that focused evaluation studies of community-based informational interventions conducted over the life-cycle of the project (“smallball” studies) are more informative and useful than randomized experiments conducted only at the project's conclusion (“powerball” studies). Method: Based on two contrasting strategies in baseball, smallball and powerball studies are compared and contrasted, emphasizing how the distinctive features of community-based interventions lend advantage to smallball approaches. Results: Smallball evaluations have several important advantages over powerball evaluations: before system development, they ensure that information resources address real community needs; during deployment, they ensure that the systems are suited to the capabilities of the users and to community constraints; and, after deployment, they enable as much as possible to be learned about the effects of the intervention in environments where randomized studies are usually impossible. Implications: Many in informatics see powerball studies as the only legitimate form of evaluation and so expect powerball studies to be done. These expectations should be revised in favor of smallball studies. PMID:16239957

  17. Space station/base food system study. Volume 1: Systems design handbook

    NASA Technical Reports Server (NTRS)

    1970-01-01

    A description is given of the approach used in a study to identify and define engineering data for a spectrum of possible items and equipment comprising potential food systems. In addition, the material presented includes: (1) the study results containing the candidate concepts considered and technical data, performance characteristics, and sketches for each of the concepts by functional area; (2) human factors considerations for crew tasks; (3) shuttle supply interface requirements; (4) special food system study areas; and (5) recommendations and conclusions based on the study results.

  18. Mortality study of civilian employees exposed to contaminated drinking water at USMC Base Camp Lejeune: a retrospective cohort study

    PubMed Central

    2014-01-01

    Background Two drinking water systems at U.S. Marine Corps Base Camp Lejeune, North Carolina were contaminated with solvents during 1950s-1985. Methods We conducted a retrospective cohort mortality study of 4,647 civilian, full-time workers employed at Camp Lejeune during 1973–1985 and potentially exposed to contaminated drinking water. We selected a comparison cohort of 4,690 Camp Pendleton workers employed during 1973–1985 and unexposed to contaminated drinking water. Mortality follow-up period was 1979-2008. Cause-specific standardized mortality ratios utilized U.S. age-, sex-, race-, and calendar period-specific mortality rates as reference. We used survival analysis to compare mortality rates between Camp Lejeune and Camp Pendleton workers and assess the effects of estimated cumulative contaminant exposures within the Camp Lejeune cohort. Ground water contaminant fate/transport and distribution system models provided monthly estimated contaminant levels in drinking water serving workplaces at Camp Lejeune. The confidence interval (CI) indicated precision of effect estimates. Results Compared to Camp Pendleton, Camp Lejeune workers had mortality hazard ratios (HRs) >1.50 for kidney cancer (HR = 1.92, 95% CI: 0.58, 6.34), leukemias (HR = 1.59, 95% CI: 0.66, 3.84), multiple myeloma (HR = 1.84, 95% CI: 0.45, 7.58), rectal cancer (HR = 1.65, 95% CI: 0.36, 7.44), oral cavity cancers (HR = 1.93, 95% CI: 0.34, 10.81), and Parkinson’s disease (HR = 3.13, 95% CI: 0.76, 12.81). Within the Camp Lejeune cohort, monotonic exposure-response relationships were observed for leukemia and vinyl chloride and PCE, with mortality HRs at the high exposure category of 1.72 (95% CI: 0.33, 8.83) and 1.82 (95% CI: 0.36, 9.32), respectively. Cumulative exposures were above the median for most deaths from cancers of the kidney, esophagus, rectum, prostate, and Parkinson’s disease, but small numbers precluded evaluation of exposure-response relationships. Conclusion The study found

  19. Joint Analysis for Genome-Wide Association Studies in Family-Based Designs

    PubMed Central

    Sha, Qiuying; Zhang, Zhaogong; Zhang, Shuanglin

    2011-01-01

    In family-based data, association information can be partitioned into the between-family information and the within-family information. Based on this observation, Steen et al. (Nature Genetics. 2005, 683–691) proposed an interesting two-stage test for genome-wide association (GWA) studies under family-based designs which performs genomic screening and replication using the same data set. In the first stage, a screening test based on the between-family information is used to select markers. In the second stage, an association test based on the within-family information is used to test association at the selected markers. However, we learn from the results of case-control studies (Skol et al. Nature Genetics. 2006, 209–213) that this two-stage approach may be not optimal. In this article, we propose a novel two-stage joint analysis for GWA studies under family-based designs. For this joint analysis, we first propose a new screening test that is based on the between-family information and is robust to population stratification. This new screening test is used in the first stage to select markers. Then, a joint test that combines the between-family information and within-family information is used in the second stage to test association at the selected markers. By extensive simulation studies, we demonstrate that the joint analysis always results in increased power to detect genetic association and is robust to population stratification. PMID:21799758

  20. A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: A simulation study

    NASA Astrophysics Data System (ADS)

    Choi, Sunghoon; Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

    2014-06-01

    Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05-1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

  1. Real World Engagement: A Case Study of a Teacher's Implementation of Project Based Learning in Social Studies

    ERIC Educational Resources Information Center

    Bullock, Daniel Kelvin

    2013-01-01

    Social studies has often had a reputation amongst students for being uninteresting due to the teaching strategies and content that educators have utilized. However, in a field as diverse and relevant as social studies, there are opportunities to garner the attention of students and empower them with information to improve and enhance our democracy…

  2. Softball sliding injuries. A prospective study comparing standard and modified bases.

    PubMed

    Janda, D H; Wojtys, E M; Hankin, F M; Benedict, M E

    1988-03-25

    In a previous retrospective study, base sliding was found to be responsible for 71% of recreational softball injuries. As most injuries occurred following rapid deceleration impact against stationary bases, quick-release (breakaway) bases were evaluated as a means to modify this mechanism of injury. Six hundred thirty-three softball games were played on breakaway-base fields and 627 games were played on stationary-base fields. Forty-five sliding injuries (7%) occurred on the stationary-base diamonds and only two sliding injuries (less than 1%) occurred on the breakaway-base fields. Implementing the use of breakaway bases in recreational softball leagues could potentially achieve a significant, cost-effective reduction of injuries.

  3. Legal, ethical, and methodological considerations in the Internet-based study of child pornography offenders.

    PubMed

    Ray, James V; Kimonis, Eva R; Donoghue, Christine

    2010-01-01

    With its ever-growing penetration of remote regions of the world, the Internet provides great opportunity for conducting research. Beyond clear advantages such as increased cost-effectiveness and efficiency in collecting large samples, Internet-based research has proven particularly useful in reaching hidden or marginalized populations who engage in illegal or deviant behaviors. However, this new medium for research raises important and complex legal, ethical, and methodological/technological issues that researchers must address, particularly when studying undetected criminal behaviors. The current paper chronicles various issues that were encountered in the implementation of an active Internet-based pilot research study of child pornography (CP) users. Moreover, this study was undertaken to address a critical gap in the existing research on CP offending, which has to date primarily focused on incarcerated or convicted samples. The Internet provides the optimal medium for studying community populations of CP users, given that it has become the primary market for CP distribution. This paper is designed to serve as a guide for researchers interested in conducting Internet-based research studies on criminal and sexually deviant populations, particularly CP offenders. Several recommendations are offered based on our own experiences in the implementation of this study.

  4. Genetic regulation of inflammation-mediated activation of haemostasis: family-based approaches in population studies.

    PubMed

    Vohnout, B; Gianfagna, F; Lorenzet, R; Cerletti, C; de Gaetano, G; Donati, M B; Iacoviello, L

    2011-11-01

    Blood coagulation and inflammation play a key role in atherosclerosis and thrombosis. Candidate gene and genome wide association studies have identified potential specific genes that might have a causal role in these pathogenic processes. The analysis of quantitative traits is more powerful as they are closer to direct gene action than disease phenotypes. Thus linkage-based studies on extended families might be useful both to estimate the heritability and to map the genetic loci responsible for the regulation of the trait. Family-based studies may estimate high heritability for thrombosis and quantitative traits regarding both platelet aggregation and blood coagulation. Some specific loci relevant to thrombosis have been identified, with some of them showing a direct pleiotropic effect on the risk of thrombosis. Haemostasis factors can be activated by inflammatory stimuli. Fibrinogen level is genetically correlated with C-reactive protein levels with a link for both traits on chromosomes 12 and 21. Genes related to prostanoid biosynthesis, involved both in inflammation and thrombosis, show high heritability levels in both enzyme expression and prostanoid production. Considering that few large family-based linkage studies have as yet been performed on haemostasis and inflammation-related traits, additional studies are highly needed. We are performing a family-based linkage study on large pedigrees (750 subjects from 23 families with juvenile myocardial infarction and 31 control families), to identify genes responsible for quantitative traits involved in the pathway progressively going from inflammation to haemostasis, cell activation, thrombus formation and cardiovascular events.

  5. Comparing Web-Based and Classroom-Based Learning: A Quantitative Study.

    ERIC Educational Resources Information Center

    Thirunarayanan, M. O.; Perez-Prado, Aixa

    2002-01-01

    Compared the achievement of preservice teachers in two sections of a course on teaching English to speakers of other languages, one taught in a traditional classroom setting and the other offered online. Findings suggest that students in the Web-based section achieved more than their classroom-based counterparts. (Author/LRW)

  6. Suicide in the media: a quantitative review of studies based on non-fictional stories.

    PubMed

    Stack, Steven

    2005-04-01

    Research on the effect of suicide stories in the media on suicide in the real world has been marked by much debate and inconsistent findings. Recent narrative reviews have suggested that research based on nonfictional models is more apt to uncover imitative effects than research based on fictional models. There is, however, substantial variation in media effects within the research restricted to nonfictional accounts of suicide. The present analysis provides some explanations of the variation in findings in the work on nonfictional media. Logistic regression techniques applied to 419 findings from 55 studies determined that: (1) studies measuring the presence of either an entertainment or political celebrity were 5.27 times more likely to find a copycat effect, (2) studies focusing on stories that stressed negative definitions of suicide were 99% less likely to report a copycat effect, (3) research based on television stories (which receive less coverage than print stories) were 79% less likely to find a copycat effect, and (4) studies focusing on female suicide were 4.89 times more likely to report a copycat effect than other studies. The full logistic regression model correctly classified 77.3% of the findings from the 55 studies. Methodological differences among studies are associated with discrepancies in their results. PMID:15843330

  7. When Intraclass Correlation Coefficients Go Awry: A Case Study From a School-Based Smoking Prevention Study in South Africa

    PubMed Central

    Zhang, Nanhua; Vaughan, Roger D.; Reddy, Sasiragha Priscilla; James, Shamagonam; Murray, David M.

    2010-01-01

    Objectives. We conducted a group randomized trial of 2 South African school-based smoking prevention programs and examined possible sources and implications of why our actual intraclass correlation coefficients (ICCs) were significantly higher than the ICC of 0.02 used to compute initial sample size requirements. Methods. Thirty-six South African high schools were randomly assigned to 1 of 3 experimental groups. On 3 occasions, students completed questionnaires on tobacco and drug use attitudes and behaviors. We used mixed-effects models to partition individual and school-level variance components, with and without covariate adjustment. Results. For 30-day smoking, unadjusted ICCs ranged from 0.12 to 0.17 across the 3 time points. For lifetime smoking, ICCs ranged from 0.18 to 0.22; for other drug use variables, 0.02 to 0.10; and for psychosocial variables, 0.09 to 0.23. Covariate adjustment substantially reduced most ICCs. Conclusions. The unadjusted ICCs we observed for smoking behaviors were considerably higher than those previously reported. This effectively reduced our sample size by a factor of 17. Future studies that anticipate significant cluster-level racial homogeneity may consider using higher-value ICCs in sample-size calculations to ensure adequate statistical power. PMID:20167897

  8. The study of electrical conductivity and diffusion behavior of water-based and ferro/ferricyanide-electrolyte-based alumina nanofluids.

    PubMed

    Liu, Chang; Lee, Hyeonseok; Chang, Ya-Huei; Feng, Shien-Ping

    2016-05-01

    Nanofluids are liquids containing suspensions of solid nanoparticles and have attracted considerable attention because they undergo substantial mass transfer and have many potential applications in energy technologies. Most studies on nanofluids have used low-ionic-strength solutions, such as water and ethanol. However, very few studies have used high-ionic-strength solutions because the aggregation and sedimentation of nanoparticles cause a stability problem. In this study, a stable water-based alumina nanofluid was prepared using stirred bead milling and exhibits a high electrical conductivity of 2420 μS/cm at 23 °C and excellent stability after five severe freezing-melting cycles. We then developed a process for mixing the water-based nanofluid with a high-ionic-strength potassium ferro/ferricyanide electrolyte and sodium dodecyl sulfate by using stirred bead milling and ultrasonication, thus forming a stable electrolyte-based nanofluid. According to the rotating disk electrode study, the electrolyte-based alumina nanofluid exhibits an unusual increase in the limiting current at high angular velocities, resulting from a combination of local percolation behavior and shear-induced diffusion. The electrolyte-based alumina nanofluid was demonstrated in a possible thermogalvanic application, since it is considered to be an alternative electrolyte for thermal energy harvesters because of the increased electrical conductivity and confined value of thermal conductivity. PMID:26866885

  9. The study of electrical conductivity and diffusion behavior of water-based and ferro/ferricyanide-electrolyte-based alumina nanofluids.

    PubMed

    Liu, Chang; Lee, Hyeonseok; Chang, Ya-Huei; Feng, Shien-Ping

    2016-05-01

    Nanofluids are liquids containing suspensions of solid nanoparticles and have attracted considerable attention because they undergo substantial mass transfer and have many potential applications in energy technologies. Most studies on nanofluids have used low-ionic-strength solutions, such as water and ethanol. However, very few studies have used high-ionic-strength solutions because the aggregation and sedimentation of nanoparticles cause a stability problem. In this study, a stable water-based alumina nanofluid was prepared using stirred bead milling and exhibits a high electrical conductivity of 2420 μS/cm at 23 °C and excellent stability after five severe freezing-melting cycles. We then developed a process for mixing the water-based nanofluid with a high-ionic-strength potassium ferro/ferricyanide electrolyte and sodium dodecyl sulfate by using stirred bead milling and ultrasonication, thus forming a stable electrolyte-based nanofluid. According to the rotating disk electrode study, the electrolyte-based alumina nanofluid exhibits an unusual increase in the limiting current at high angular velocities, resulting from a combination of local percolation behavior and shear-induced diffusion. The electrolyte-based alumina nanofluid was demonstrated in a possible thermogalvanic application, since it is considered to be an alternative electrolyte for thermal energy harvesters because of the increased electrical conductivity and confined value of thermal conductivity.

  10. Size-Expanded yDNA bases: An Ab Initio Study

    SciTech Connect

    Fuentes-Cabrera, Miguel A; Sumpter, Bobby G; Lipkowski, Pawel; Wells, Jack C

    2006-01-01

    xDNA and yDNA are new classes of synthetic nucleic acids characterized by having base-pairs with one of the bases larger than the natural congeners. Here these larger bases are called x- and y-bases. We recently investigated and reported the structural and electronic properties of the x-bases (Fuentes-Cabrera et al. J. Phys. Chem. B 2005, 109, 21135-21139). Here we extend this study by investigating the structure and electronic properties of the y-bases. These studies are framed within our interest that xDNA and yDNA could function as nanowires, for they could have smaller HOMO-LUMO gaps than natural DNA. The limited amount of experimental structural data in these synthetic duplexes makes it necessary to first understand smaller models and, subsequently, to use that information to build larger models. In this paper, we report the results on the chemical and electronic structure of the y-bases. In particular, we predict that the y-bases have smaller HOMO-LUMO gaps than their natural congeners, which is an encouraging result for it indicates that yDNA could have a smaller HOMO-LUMO gap than natural DNA. Also, we predict that the y-bases are less planar than the natural ones. Particularly interesting are our results corresponding to yG. Our studies show that yG is unstable because it is less aromatic and has a Coulombic repulsion that involves the amino group, as compared with a more stable tautomer. However, yG has a very small HOMO-LUMO gap, the smallest of all the size-expanded bases we have considered. The results of this study provide useful information that may allow the synthesis of an yG-mimic that is stable and has a small HOMO-LUMO gap.

  11. A comparison between conventional and LANDSAT based hydrologic modeling: The Four Mile Run case study

    NASA Technical Reports Server (NTRS)

    Ragan, R. M.; Jackson, T. J.; Fitch, W. N.; Shubinski, R. P.

    1976-01-01

    Models designed to support the hydrologic studies associated with urban water resources planning require input parameters that are defined in terms of land cover. Estimating the land cover is a difficult and expensive task when drainage areas larger than a few sq. km are involved. Conventional and LANDSAT based methods for estimating the land cover based input parameters required by hydrologic planning models were compared in a case study of the 50.5 sq. km (19.5 sq. mi) Four Mile Run Watershed in Virginia. Results of the study indicate that the LANDSAT based approach is highly cost effective for planning model studies. The conventional approach to define inputs was based on 1:3600 aerial photos, required 110 man-days and a total cost of $14,000. The LANDSAT based approach required 6.9 man-days and cost $2,350. The conventional and LANDSAT based models gave similar results relative to discharges and estimated annual damages expected from no flood control, channelization, and detention storage alternatives.

  12. Lunar base scenario cost estimates: Lunar base systems study task 6.1

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The projected development and production costs of each of the Lunar Base's systems are described and unit costs are estimated for transporting the systems to the lunar surface and for setting up the system.

  13. Lunar base applications of superconductivity: Lunar base systems study task 3.4

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The application of superconductor technology to several key aspects of an advanced-stage Lunar Base is described. Applications in magnetic energy storage, electromagnetic launching, and radiation shielding are discussed.

  14. Are Reports of Psychological Stress Higher in Occupational Studies? A Systematic Review across Occupational and Population Based Studies

    PubMed Central

    Goodwin, Laura; Ben-Zion, Ilan; Fear, Nicola T.; Hotopf, Matthew; Stansfeld, Stephen A.; Wessely, Simon

    2013-01-01

    Objectives The general health questionnaire (GHQ) is commonly used to assess symptoms of common mental disorder (CMD). Prevalence estimates for CMD caseness from UK population studies are thought to be in the range of 14–17%, and the UK occupational studies of which we are aware indicate a higher prevalence. This review will synthesise the existing research using the GHQ from both population and occupational studies and will compare the weighted prevalence estimates between them. Methods We conducted a systematic review and meta-analysis to examine the prevalence of CMD, as assessed by the GHQ, in all UK occupational and population studies conducted from 1990 onwards. Results The search revealed 65 occupational papers which met the search criteria and 15 relevant papers for UK population studies. The weighted prevalence estimate for CMD across all occupational studies which used the same version and cut-off for the GHQ was 29.6% (95% confidence intervals (CIs) 27.3–31.9%) and for comparable population studies was significantly lower at 19.1% (95% CIs 17.3–20.8%). This difference was reduced after restricting the studies by response rate and sampling method (23.9% (95% CIs 20.5%–27.4%) vs. 19.2% (95 CIs 17.1%–21.3%)). Conclusions Counter intuitively, the prevalence of CMD is higher in occupational studies, compared to population studies (which include individuals not in employment), although this difference narrowed after accounting for measures of study quality, including response rate and sampling method. This finding is inconsistent with the healthy worker effect, which would presume lower levels of psychological symptoms in individuals in employment. One explanation is that the GHQ is sensitive to contextual factors, and it seems possible that symptoms of CMD are over reported when participants know that they have been recruited to a study on the basis that they belong to a specific occupational group, as in nearly all “stress” surveys. PMID

  15. The Challenges of Ensuring Participant Consent in Internet-based Sex Studies: A Case Study of the Men’s INTernet Sex (MINTS-I and II) Studies

    PubMed Central

    Rosser, B. R. Simon; Gurak, Laura; Horvath, Keith J.; Oakes, J. Michael; Konstan, Joseph; Danilenko, Gene P.

    2013-01-01

    This study documents our experience in designing, testing, and refining human subjects’ consent protocol in 3 of the first NIH-funded online studies of HIV/STI sexual risk behavior in the USA. We considered 4 challenges primary: a) designing recruitment and enrollment procedures to ensure adequate attention to subject considerations; b) obtaining and documenting subjects’ consent; c) establishing investigator credibility through investigator-participant interactions; d) enhancing confidentiality during all aspects of the study. Human consent in online studies appears more relative, continuous, inherent, tenuous, and diverse than in offline studies. Reasons for declining consent appear related to pragmatic concerns not human subjects’ risks. Reordering the consent process, and short, chunked, stepwise, tailored consent procedures may enhance communicating information and documenting consent. PMID:24204104

  16. Study of relaxation and transport processes by means of AFM based dielectric spectroscopy

    SciTech Connect

    Miccio, Luis A.

    2014-05-15

    Since its birth a few years ago, dielectric spectroscopy studies based on atomic force microscopy (AFM) have gained a growing interest. Not only the frequency and temperature ranges have become broader since then but also the kind of processes that can be studied by means of this approach. In this work we analyze the most adequate experimental setup for the study of several dielectric processes with a spatial resolution of a few nanometers by using force mode AFM based dielectric spectroscopy. Proof of concept experiments were performed on PS/PVAc blends and PMMA homopolymer films, for temperatures ranging from 300 to 400 K. Charge transport processes were also studied by this approach. The obtained results were analyzed in terms of cantilever stray contribution, film thickness and relaxation strength. We found that the method sensitivity is strongly coupled with the film thickness and the relaxation strength, and that it is possible to control it by using an adequate experimental setup.

  17. Tatool: a Java-based open-source programming framework for psychological studies.

    PubMed

    von Bastian, Claudia C; Locher, André; Ruflin, Michael

    2013-03-01

    Tatool (Training and Testing Tool) was developed to assist researchers with programming training software, experiments, and questionnaires. Tatool is Java-based, and thus is a platform-independent and object-oriented framework. The architecture was designed to meet the requirements of experimental designs and provides a large number of predefined functions that are useful in psychological studies. Tatool comprises features crucial for training studies (e.g., configurable training schedules, adaptive training algorithms, and individual training statistics) and allows for running studies online via Java Web Start. The accompanying "Tatool Online" platform provides the possibility to manage studies and participants' data easily with a Web-based interface. Tatool is published open source under the GNU Lesser General Public License, and is available at www.tatool.ch. PMID:22723043

  18. Tatool: a Java-based open-source programming framework for psychological studies.

    PubMed

    von Bastian, Claudia C; Locher, André; Ruflin, Michael

    2013-03-01

    Tatool (Training and Testing Tool) was developed to assist researchers with programming training software, experiments, and questionnaires. Tatool is Java-based, and thus is a platform-independent and object-oriented framework. The architecture was designed to meet the requirements of experimental designs and provides a large number of predefined functions that are useful in psychological studies. Tatool comprises features crucial for training studies (e.g., configurable training schedules, adaptive training algorithms, and individual training statistics) and allows for running studies online via Java Web Start. The accompanying "Tatool Online" platform provides the possibility to manage studies and participants' data easily with a Web-based interface. Tatool is published open source under the GNU Lesser General Public License, and is available at www.tatool.ch.

  19. The Major Quantitative Findings of a Study of the English Language-Based Study Skills Problems of Two Groups of Foreign Students at an American University.

    ERIC Educational Resources Information Center

    Ali, M. Solaiman

    A study examined the English-language-based study skills problems of 44 Indonesian and 57 Malaysian students studying at Indiana University, Bloomington. The Indonesian and Malaysian student groups represented non-Commonwealth and Commonwealth students sharing the same native language roots but differing in terms of previous exposure to the…

  20. Integrating Web-Based Applications into Aged Care: Two Case Studies and Discussion.

    PubMed

    Rehm, Imogen C; Musić, Selma; Carlsson, Anthony; Scanlan, Faye; Silver, Mark; Bhar, Sunil S

    2016-09-01

    In anticipation of the growing need for adequate mental health care for older adults in residential aged care facilities, psychologists are challenged to overcome several barriers that impede the uptake and delivery of their services in such settings. Information and communication technologies (ICT) have strong potential to overcome some of these barriers by supporting the delivery of evidence-based psychosocial treatments for common psychogeriatric issues. This paper presents two case studies that illustrate when and how psychologists can use various ICT applications (e.g., tablet devices, web-based applications) integrated with cognitive behavioural and reminiscence-based therapies. Both case studies demonstrate that ICT can effectively support the therapeutic alliance, enhance therapeutic engagement, and individualize treatment delivery to accommodate the needs of elderly patients. It is hoped that these case studies will encourage clinicians to consider using ICT to augment therapy with their elderly patients. PMID:27073103