Measurement Matters: Estimating Students’ Community Engagement Participation

Many community engagement and service-learning studies require the researcher to identify whether or not a particular student has participated in an engagement activity. In this article, the author explores the importance and challenge of measuring college students’ community engagement by detailing one institution’s rigorous effort to answer the question, “What percentage of students participate in community engagement during their time at college?” The article illustrates the results of a study in which an institution supplemented an existing database of student participation with several other nontraditional sources of student participation data to construct an expanded measure of engagement. Results indicated that, compared with the expanded measure, the existing database produced a biased estimate of engagement with regard to gender, race and ethnicity, financial aid, and athletic status. Implications for future research, assessment, and practice are discussed.

Can We Count on Counting? An Analysis of the Validity of Community Engagement Survey Measures

Researchers use various survey efforts to understand students’ community engagement experiences. Among the crucial pieces of information for both academic and applied research is the extent to which (or whether or not) students participate in community engagement activities. However, recent studies have questioned the validity of many college student survey items. This paper describes an exploratory study that sought to investigate the validity of several survey items related to students’ community engagement participation. The study found that large percentages of students who have taken community-based learning courses do not accurately report these experiences on student surveys and examines what factors relate to misreporting. Implications for future community engagement research are discussed.

Mirror on the Field: Gender, Authorship, and Research Methods in Higher Education’s Leading Journals

Framed conceptually by gender equity, gender homophily, the contest regime of blind peer-review publishing, and the gendered nature of the quantitative–qualitative debate, this study investigated the intersection of authorship, gender, and methodological characteristics of 408 articles published from 2006 to 2010 in 3 major higher education journals. Nonbinary coding of author gender based on pronouns identified via Web searches virtually eliminated missing data and likely reduced error. Results suggest movement toward gender parity over time; however, women’s representation among authors does not appear commensurate with representation in the field. Findings revealed gendered use of research methods, with qualitative articles more likely to be first-authored by women and quantitative articles more likely to be first-authored by men. Nevertheless, articles first-authored by both women and men were more likely to use quantitative than qualitative methods. Quantitative research, more so than qualitative research, appears to be a site of cogender collaboration, which has increased over time. This portrait of the intersection of authorship, gender, and research methods provides an empirical foundation for discussion and inquiry about gender and scholarship in the field, and the results of our study are generative for future research

Magnetospectroscopy of symmetric and anti-symmetric states in double quantum wells

The experimental results obtained for the magneto-transport in the InGaAs/InAlAs double quantum wells (DQW) structures of two different shapes of wells are reported. The beating-effect occurred in the Shubnikov-de Haas (SdH) oscillations was observed for both types of the structures at low temperatures in the parallel transport when magnetic field was perpendicular to the layers. An approach to the calculation of the Landau levels energies for DQW structures was developed and then applied to the analysis and interpretation of the experimental data related to the beating-effect. We also argue that in order to account for the observed magneto-transport phenomena (SdH and Integer Quantum Hall effect), one should introduce two different quasi-Fermi levels characterizing two electron sub-systems regarding symmetry properties of their states, symmetric and anti-symmetric ones which are not mixed by electron-electron interaction.Comment: 20 pages, 20 figure

Effect of Spatial Charge Inhomogeneity on 1/f Noise Behavior in Graphene

Scattering mechanisms in graphene are critical to understanding the limits of signal-to-noise-ratios of unsuspended graphene devices. Here we present the four-probe low frequency noise (1/f) characteristics in back-gated single layer graphene (SLG) and bilayer graphene (BLG) samples. Contrary to the expected noise increase with the resistance, the noise for SLG decreases near the Dirac point, possibly due to the effects of the spatial charge inhomogeneity. For BLG, a similar noise reduction near the Dirac point is observed, but with a different gate dependence of its noise behavior. Some possible reasons for the different noise behavior between SLG and BLG are discussed.Comment: 28 pages, 3 figures + 3 supplement figure

Parallel magnetotransport in multiple quantum well structures

The results of investigations of parallel magnetotransport in AlGaAs/GaAs and InGaAs/InAlAs/InP multiple quantum wells structures (MQW’s) are presented in this paper. The MQW’s were obtained by metalorganic vapour phase epitaxy with different shapes of QW, numbers of QW and levels of doping. The magnetotransport measurements were performed in wide region of temperatures (0.5–300 K) and at high magnetic fields up to 30 T (B is perpendicular and current is parallel to the plane of the QW). Three types of observed effects are analyzed: quantum Hall effect and Shubnikov—de Haas oscillations at low temperatures (0.5–6 K) as well as magnetophonon resonance at higher temperatures (77–300 K)

Genetic risk prediction of atrial fibrillation

Background—Atrial fibrillation (AF) has a substantial genetic basis. Identification of individuals at greatest AF risk could minimize the incidence of cardioembolic stroke. Methods—To determine whether genetic data can stratify risk for development of AF, we examined associations between AF genetic risk scores and incident AF in five prospective studies comprising 18,919 individuals of European ancestry. We examined associations between AF genetic risk scores and ischemic stroke in a separate study of 509 ischemic stroke cases (202 cardioembolic [40%]) and 3,028 referents. Scores were based on 11 to 719 common variants (≥5%) associated with AF at P-values ranging from <1x10-3 to <1x10-8 in a prior independent genetic association study. Results—Incident AF occurred in 1,032 (5.5%) individuals. AF genetic risk scores were associated with new-onset AF after adjusting for clinical risk factors. The pooled hazard ratio for incident AF for the highest versus lowest quartile of genetic risk scores ranged from 1.28 (719 variants; 95%CI, 1.13-1.46; P=1.5x10-4) to 1.67 (25 variants; 95%CI, 1.47-1.90; P=9.3x10-15). Discrimination of combined clinical and genetic risk scores varied across studies and scores (maximum C statistic, 0.629-0.811; maximum ΔC statistic from clinical score alone, 0.009-0.017). AF genetic risk was associated with stroke in age- and sex-adjusted models. For example, individuals in the highest versus lowest quartile of a 127-variant score had a 2.49-fold increased odds of cardioembolic stroke (95%CI, 1.39-4.58; P=2.7x10-3). The effect persisted after excluding individuals (n=70) with known AF (odds ratio, 2.25; 95%CI, 1.20-4.40; P=0.01). Conclusions—Comprehensive AF genetic risk scores were associated with incident AF beyond associations for clinical AF risk factors, though offered small improvements in discrimination. AF genetic risk was also associated with cardioembolic stroke in age- and sex-adjusted analyses. Efforts are warranted to determine whether AF genetic risk may improve identification of subclinical AF or help distinguish between stroke mechanisms