173 research outputs found
An Interactive Multimedia Instructional Program on Statistics: An Instance of Design-Based Research
Studentsâ fail or demonstrate slow progress in research methods and basic statistics courses if they have difficulty on identifying different types of variables. A web-based interactive multimedia instructional program for bringing them up to speed on this topic was designed and evaluated for effectiveness with 90 undergraduate college students. A significant effect of this program on studentsâ knowledge gain was determined. Careful consideration of the elements that made the teaching principles effective was taken by: (1) grounding the instructional design approach in cognitive psychology; and (2) collecting empirical data to validate the program features and instructional design methods used
Selection for Drought Tolerance in Dry Bean Derived from the Mesoamerican Gene Pool in Western Nebraska
Dry bean (Phaseolus vulgaris L.) is highly susceptible to drought stress, and drought affects 60% of global bean production. We evaluated elite exotic dry bean germplasm derived from the Mesoamerican gene pool for drought tolerance, yield, and adaptation to western Nebraska during 2006 and 2007 at three research sites. Seven tropical lines were evaluated with two great northern cultivars (Matterhorn and Beryl- R) and one pinto cultivar (Bill-Z) serving as checks. Adjacent nonstressed (NS) and droughtstressed (DS) blocks were evaluated. Within each block, the selected lines were assigned to experimental units using a randomized complete block design with four replications at each location. On average, yield was 60% less, 100-seed weight was 19.2% lower, and maturity occurred 4 d earlier under DS than under NS conditions. Beryl-R, SER 22, and Matterhorn had the greatest average yield under both NS (3564, 3347, and 3440 kg haâ1, respectively) and DS (1701, 1773, and 1584 kg haâ1, respectively). These genotypes were also the most drought tolerant based on the drought susceptibility index (0.9, 0.8, and 0.9, respectively) and geometric mean (2462, 2436, and 2335, respectively). Based on these results, Matterhorn, Beryl-R, and SER 22 show the most promise for use in breeding for drought tolerance
Registration of the Chickpea Germplasm PHREC-Ca-Comp. #1 with Enhanced Resistance to Ascochyta Blight
The chickpea or garbanzo bean (Cicer arietinum L.) germplasm PHREC-Ca-Comp. #1 (Reg. No. GP-282, PI 659664) was developed by the former Alternative Crops Breeding Program at the University of Nebraska Agricultural Research Division and was released in 2010. It was bred specifically for adaptation to growing conditions in Nebraska and for enhanced resistance to Ascochyta blight, a major disease of chickpea caused by Ascochyta rabiei (Pass.) Labr. PHREC-Ca- Comp. #1 is a composite of PI 315797, PI 343014, PI 379217, PI 471915, PI 598080, and W6 17256. The composite was developed in the fall of 2002 and was evaluated in six irrigated and four dryland environments at Scottsbluff, Sidney, and Alliance, NE, from 2004 to 2009. Across irrigated environments, PHREC-Ca-Comp. #1 had the lowest severity rating for Ascochyta blight and a higher yield under both irrigated and dryland conditions than âSierraâ, âDwelleyâ, âDylanâ, and âTroyâ. PHREC-Ca-Comp. #1 is a small, round, cream-colored kabuli-type chickpea. It exhibits an upright, indeterminate growth habit. Plants average 66 cm in height and have excellent resistance to lodging. PHREC-Ca-Comp. #1 has a fern leaf structure and white flowers and blooms 44 d after planting. It is a midseason bean, maturing 116 d after planting. Although its seed size does not meet commercial standards, PHREC-Ca-Comp. #1 has value in breeding programs as a source of resistance to Ascochyta blight and because of its high yield potential
An overview of assessment methodology for obesity-related variables in infants at risk
Background: The first 2 years of a childâs life are a particularly critical time period for obesity prevention.
Aim: An increasing amount of research across the world is aimed at understanding factors that impact early childhood obesity and developing interventions that target these factors effectively. With this growing interest, new and interdisciplinary research teams are developing to meet this research need. Due to rapid growth velocity during this phase of the lifespan, typical assessments used in older populations may not be valid or applicable in infants, and investigators need to be aware of the pros and cons of specific methodological strategies.
Methods: This paper provides an overview of methodology available to assess obesity-related factors in the areas of anthropometry and body composition, nutrient intake, and energy expenditure in infants aged 0â2 years.
Results: Gold standard measures for body composition, such as dual-energy X-ray absorptiometry (DXA) or other imaging techniques, are costly, require highly trained personnel, and are limited for research application. Nutrient intake methodology primarily includes surveys and questionnaires completed via parent proxy report. In terms of energy expenditure, methods of calorimetry are expensive and may not differentiate between different activities. Questionnaires or physical activity sensors offer another way of energy expenditure assessment. However, questionnaires have a certain recall bias, while the sensors require further validation.
Conclusions: Overall, in addition to understanding the pros and cons of each assessment tool, researchers should take into consideration the experience of the interdisciplinary team of investigators, as well as the cost and availability of measures at their institution
Regiochemistry of donor dendrons controls the performance of thermally activated delayed fluorescence dendrimer emitters for high efficiency solution-processed organic light-emitting diodes
This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie SkĆodowska-Curie grant agreement No. 838009 (TSFP) and No 812872 (TADFlife). D.S. acknowledges support from the Marie SkĆodowska-Curie Individual Fellowship, the National Postdoctoral Program for Innovative Talents (BX201700164), the Jiangsu Planned Projects for Postdoctoral Research Funds (2018K011A). E.Z.-C. is a Royal Society Leverhulme Trust Senior Research fellow (SRFâR1â201089). The St Andrews team would also like to thank the Leverhulme Trust (RPG-2016047) and EPSRC (EP/P010482/1) for financial support. This work was also supported by Comunidad de Madrid (Spain) â multiannual agreement with UC3M (âExcelencia para el Profesorado Universitarioâ â EPUC3M14) â Fifth regional research plan 2016-2020 and by the Spanish Ministry of Science, Innovation and Universities (MICINN) through project RTI2018-101020-B-100. X.Z. would like to thank the support from the National Key Research & Development Program of China (Grant No. 2020YFA0714601, 2020YFA0714604), the National Natural Science Foundation of China (Grant No. 52130304, 51821002), Suzhou Key Laboratory of Functional Nano & Soft Materials, Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the 111 Project, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices.The potential of dendrimers exhibiting thermally activated delayed fluorescence (TADF) as emitters in solution-processed organic light-emitting diodes (OLEDs) has to date not yet been realized. This in part is due to a poor understanding of the structureâproperty relationship in dendrimers where reports of detailed photophysical characterization and mechanism studies are lacking. In this report, using absorption and solvatochromic photoluminescence studies in solution, the origin and character of the lowest excited electronic states in dendrimers with multiple dendritic electron-donating moieties connected to a central electron-withdrawing core via a para- or a meta-phenylene bridge is probed. Characterization of host-free OLEDs reveals the superiority of meta-linked dendrimers as compared to the already reported para-analogue. Comparative temperature-dependent time-resolved solid-state photoluminescence measurements and quantum chemical studies explore the effect of the substitution mode on the TADF properties and the reverse intersystem crossing (RISC) mechanism, respectively. For TADF dendrimers with similarly small âEST, it is observed that RISC can be enhanced by the regiochemistry of the donor dendrons due to control of the reorganization energies, which is a heretofore unexploited strategy that is distinct from the involvement of intermediate triplet states through a nonadiabatic (vibronic) coupling with the lowest singlet charge transfer state.Publisher PDFPeer reviewe
Recommended from our members
Influences of increasing temperature on Indian wheat: quantifying limits to predictability
As climate changes, temperatures will play an increasing role in determining crop yield. Both
climate model error and lack of constrained physiological thresholds limit the predictability of
yield. We used a perturbed-parameter climate model ensemble with two methods of
bias-correction as input to a regional-scale wheat simulation model over India to examine
future yields. This model configuration accounted for uncertainty in climate, planting date,
optimization, temperature-induced changes in development rate and reproduction. It also
accounts for lethal temperatures, which have been somewhat neglected to date. Using
uncertainty decomposition, we found that fractional uncertainty due to temperature-driven
processes in the crop model was on average larger than climate model uncertainty (0.56 versus
0.44), and that the crop model uncertainty is dominated by crop development. Simulations
with the raw compared to the bias-corrected climate data did not agree on the impact on future
wheat yield, nor its geographical distribution. However the method of bias-correction was not
an important source of uncertainty. We conclude that bias-correction of climate model data
and improved constraints on especially crop development are critical for robust impact
predictions
Impact of meningococcal B (4CMenB) vaccine on pharyngeal Neisseria meningitidis carriage density and persistence in adolescents
La(, ) cross sections constrained with statistical decay properties of La nuclei
The nuclear level densities and -ray strength functions of
La were measured using the La(He, ),
La(He, He) and La(d, p) reactions. The
particle- coincidences were recorded with the silicon particle
telescope (SiRi) and NaI(Tl) (CACTUS) arrays. In the context of these
experimental results, the low-energy enhancement in the A140 region is
discussed. The La( cross sections were calculated
at - and -process temperatures using the experimentally measured nuclear
level densities and -ray strength functions. Good agreement is found
between La( calculated cross sections and previous
measurements
A Bibliometric Analysis of Select Information Science Print and Electronic Journals in the 1990s
This paper examines three e-journals and one paper journal begun in the 1990s within the information science genre. In addition, these journals are compared to what is perhaps the leading information science journal, one that has been published continuously for fifty years. The journals we examine are CyberMetrics, Information Research, the Journal of Internet Cataloging, Libres, and the Journal of the American Society for Information Science. We find that there are a number of important differences among the journals. These include frequency of publication, publication size, number of authors, and the funding status of articles. We also find differences among journals for distributions of authors by gender and corporate authors by region. Some of the regional differences can be explained by journal maturation -- the more mature the journal the greater the dispersion. We also find that women are more likely to publish in the newer journals than in JASIS. The fact that a journal is or is not an e-journal does not appear to affect its presence or behaviour as an information science journal
- âŠ