Omnibus Hypothesis Testing in Dominance-Based Ordinal Multiple Regression.

Often quantitative data in the social sciences have only ordinal justification. Problems of interpretation can arise when least squares multiple regression (LSMR) is used with ordinal data. Two ordinal alternatives are discussed, dominance-based ordinal multiple regression (DOMR) and proportional odds multiple regression. The Q2 statistic is introduced for testing the omnibus null hypothesis in DOMR. A simulation study is discussed that examines the actual Type I error rate and power of Q2 in comparison to the LSMR omnibus F test under normality and non-normality. Results suggest that Q2 has favorable sampling properties as long as the sample size-to-predictors ratio is not too small, and Q2 can be a good alternative to the omnibus F test when the response variable is non-normal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stochastic models for degradation-based reliability

This paper presents a degradation-based procedure for estimating the full and residual lifetime distribution of a single-unit system subject to Markovian deterioration. The hybrid approach unites real degradation measures with analytical, stochastic failure models to numerically compute the distributions and their moments. Two distinct models are shown to perform well when compared with simulated data. Moreover, results obtained from the second model are compared with empirically generated lifetimes of 2024-T3 aluminum alloy specimens. The numerical experiments indicate that the proposed techniques are useful for remaining lifetime prognosis in both cases.     

Laser-induced fluorescence spectroscopy of dark- and light-adapted bean (Phaseolus vulgaris L.) and wheat (Triticum aestivum L.) plants grown under three irradiance levels and subjected to fluctuating lighting conditions

Fluorescence spectral characteristics associated with growth under different irradiance levels, and during rapidly changing lighting conditions, were measured on healthy bean (Phaseolus vulgaris L.) and wheat (Triticum aestivum L.) plants using a laser-induced fluorescence spectroscopy (LIFS) system. The LIFS system was designed as a prototype of a handheld field remote sensing system and used a tripled Nd:YAG laser to produce ultraviolet (UV) excitation photons at 355 nm. Dark-adapted canopies of the bean and wheat plants grown under 150, 300, or 450 μmol m⁻² s⁻¹ of photosynthetically active radiation (PAR) exhibited LIFS spectra with higher relative fluorescence intensities than emissions from light-adapted plants at all three light levels. Blue/red and blue/far-red leaf fluorescence ratios for both bean and wheat plants increased dramatically as PAR increased, but red/far-red ratios decreased as PAR increased. Light-adapted plants grown under the three light levels were then subjected to several rapidly changing lighting conditions. Plants were exposed sequentially to 150, 300, and 650 μmol m⁻² s⁻¹ PAR from metal halide lamps, followed by a fourth light treatment of 650 μmol m⁻² s⁻¹ PAR from a mixture of metal halide and tungsten-halogen lamps. The tungsten-halogen lamps added significant amounts of near-infrared (NIR) irradiation to the background light environment provided by the metal halide lamps. Results indicated that both bean and wheat canopies generally exhibited stable blue, green, red, and far-red fluorescence emissions when plants were exposed to 150, 300, and 650 μmol m⁻² s⁻¹ PAR from the metal halide lamps. In contrast, when bean and wheat plants were exposed to the NIR-enriched light supplied by the tungsten-halogen lamps, blue and green fluorescence remained stable, but red and far-red fluorescence increased dramatically immediately after exposure to the NIR photons. However, the increased levels of red and far-red fluorescence observed after exposure to NIR light decreased quickly (within 55 s) and returned to “baseline” levels observed at the start of the rapidly changing light experiments. Results indicate that handheld LIFS instruments can be used for remote sensing of plant canopies under a diversity of lighting conditions including full darkness, dawn and dusk lighting environments, and under rapidly changing light environments similar to those encountered on partly cloudy days.     

Motivation of Engineering Students to Participate in Teaching Evaluations

This study employs expectancy theory to evaluate some key factors that motivate students to participate in the teaching evaluation process. The results show that engineering students generally consider the improvement of teaching to be the most important outcome of teaching evaluations, followed by the improvement of course content and format. Making the results of evaluations available for students' decisions on course and instructor selection ranked third, while the least important use was influencing a professor's tenure, promotion, and salary raise. Students' motivation to participate in teaching evaluations is also impacted significantly by their expectation that they will be able to provide meaningful feedback.     

When viewing variations in paintings by Mondrian, aesthetic preferences correlate with pupil size.

Observers consciously prefer Mondrian's paintings in their original orientation compared with a rotated position—the “oblique effect” (Latto, Brain, & Kelly, 2000). However, this finding's premise, that all vertical–horizontal orientations of the thick black lines in Mondrian's oeuvre are preferred, overlooks the fact that the overall balance of these images is also altered when they are reoriented. Thus, balance may regulate the oblique effect, which might influence conscious aesthetic preferences. To address this issue, we explore Hess's (1965, 1972) claim that observers will unconsciously increase their pupil diameter to pleasing images and constrict it to unpleasant images. We overcame Hess's methodological limitation of not keeping his images' luminances and contrast constant across conditions by presenting eight Mondrian paintings (1921–1944) to 30 observers on a CRT for 20 s each in either their original or seven rotated positions. Simultaneously, we measured their pupil size while asking them to report how (dis)pleasing they found each image. We found both evidence for the oblique effect (where image rotation hampers preference) and a correlation between this consciously reported aesthetic preference and unconsciously derived pupil size. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological Research Online: Report of Board of Scientific Affairs' Advisory Group on the Conduct of Research on the Internet.

As the Internet has changed communication, commerce, and the distribution of information, so too it is changing psychological research. Psychologists can observe new or rare phenomena online and can do research on traditional psychological topics more efficiently, enabling them to expand the scale and scope of their research. Yet these opportunities entail risk both to research quality and to human subjects. Internet research is inherently no more risky than traditional observational, survey, or experimental methods. Yet the risks and safeguards against them will differ from those characterizing traditional research and will themselves change over time. This article describes some benefits and challenges of conducting psychological research via the Internet and offers recommendations to both researchers and institutional review boards for dealing with them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

COVID-19 pandemic dynamics in India,the SARS-CoV-2 Delta variant and implications for vaccination

The Delta variant is a major SARS-CoV-2 variant of concern first identified in India. To better understand COVID-19 pandemic dynamics and Delta, we use multiple datasets and model-inference to reconstruct COVID-19 pandemic dynamics in India during March 2020–June 2021. We further use the large discrepancy in one- and two-dose vaccination coverage in India (53% versus 23% by end of October 2021) to examine the impact of vaccination and whether prior non-Delta infection can boost vaccine effectiveness (VE). We estimate that Delta escaped immunity in 34.6% (95% CI: 0–64.2%) of individuals with prior wild-type infection and was 57.0% (95% CI: 37.9–75.6%) more infectious than wild-type SARS-CoV-2. Models assuming higher VE among non-Delta infection recoverees, particularly after the first dose, generated more accurate predictions than those assuming no such increases (best-performing VE setting: 90/95% versus 30/67% baseline for the first/second dose). Counterfactual modelling indicates that high vaccination coverage for first vaccine dose in India combined with the boosting of VE among recoverees averted around 60% of infections during July–mid-October 2021. These findings provide support to prioritizing first-dose vaccination in regions with high underlying infection rates, given continued vaccine shortages and new variant emergence.     

High electrical performance liquid-phase HBr oxidation gate insulator of InAlAs/InGaAs metamorphic MOS-mHEMT

The InAlAs/InGaAs metal-oxide-semiconductor metamorphic high electron mobility transistors (MOS-mHEMTs) were demonstrated by using liquid-phase HBr treatment technology to form a high-quality gate insulator layer. In this study, liquid-phase HBr treatment technology was used instead of traditional plasma-assisted chemical vapor deposition (PECVD) because the proposed technology can prevent the device from plasma-induced damage. The novel HBr + ultraviolet (UV) illumination treated InGaAs provided a lower surface states such that MOS structure can be efficiently obtained. Besides, based on the atomic force microscopy (AFM) measurement, the native oxides film formed by HBr + UV illumination treatment also provided a better surface roughness compared to traditional NH₄OH and only HBr treatment solutions. It is beneficial for reducing the surface traps and lowering the leakage current in MOS-mHEMTs. Based on the flicker noise and load-pull power measurement results, HBr + UV treatment mHEMT achieved a low flicker noise at high current level and the power-added efficiency can be enhanced up to 9%. Therefore, the novel liquid phase method of HBr + UV illumination treatment exhibited a highly potential for low noise microwave power device applications.     

Analysis of the diametral compression method for determining the tensile strength of transparent magnesium aluminate spinel

Attempts were made to determine the inherent tensile strength of a coarse-grained, hot-pressed magnesium aluminate spinel (MgAl₂O₄) using the diametral compression test. Thick (9.6 mm) disk specimens were machined from a large (356 mm square) plate of spinel. Two pairs of tungsten carbide (WC) platens, one with flat surfaces and the other with a 20° half-arc and radius matched to the disk diameter, were used to transfer the applied load. Specimens tested using the platens with the matched radius had strength values almost 50% higher than those tested using flat platens. Images of the fracture process captured using a high-speed camera showed that irrespective of the type of platens used, fracture consistently initiated at the loading interface, resulting in an invalid test. These results show that the diametral compression test method is not appropriate for determining the tensile strength of this spinel and it raises concerns about the applicability of the method for any advanced ceramic.     

What types of safety nets would be most efficient and effective for protecting small farmers and the poor against volatile food prices?

Smallholder farmers in dryland areas, including the Arab region, face many risks, including those relating to weather and markets. While risk taking is necessary for economic development, many risks are so severe that responses to them entail long-term losses. Social risk management is a family of tools that facilitates efficient risk management and can help eliminate risk-related poverty traps. Safety nets form an important part of the social risk management toolkit; it is therefore important to evaluate their effectiveness. This review has identified several considerations for the design and implementation of safety nets to improve food security among small-scale producers in dryland areas. The main conclusions are: safety nets must be part of an integrated risk management strategy; they should be designed to contribute to long-term agricultural growth; and more effort is needed to establish efficient risk management mechanisms prior to crises.