Students’ Perceptions of Course Syllabi: The Role of Syllabi in Motivating Students

In this mixed methods study, researchers explored students’ perceptions of different types of syllabi, the course, and the instructor articulated through the syllabi. Students were randomly assigned to read one of two US History syllabi: a content-focused syllabus (CFS), characterized as a traditional, content-focused, policy-laden syllabus; or a learning-focused syllabus (LFS), characterized by strong learning objectives, authentic assessments, and a positive, motivating tone. Results show that LFS participants (n=61) had significantly more positive perceptions of the document, the course, and the instructor described by the document than CFS participants (n=66). LFS participants found, for example, more of the syllabus components to be useful, anticipated more student involvement in class, expected to learn more useful concepts and skills, and anticipated that the instructor would help them be successful. Although additional research is needed to determine generalizability of these results, we conclude that instructors have little to lose and much to gain by creating a learning-focused syllabus

Under Pressure: Quenching Star Formation in Low-Mass Satellite Galaxies via Stripping

Recent studies of galaxies in the local Universe, including those in the Local Group, find that the efficiency of environmental (or satellite) quenching increases dramatically at satellite stellar masses below ~ $10^8\ {\rm M}_{\odot}$. This suggests a physical scale where quenching transitions from a slow "starvation" mode to a rapid "stripping" mode at low masses. We investigate the plausibility of this scenario using observed HI surface density profiles for a sample of 66 nearby galaxies as inputs to analytic calculations of ram-pressure and viscous stripping. Across a broad range of host properties, we find that stripping becomes increasingly effective at $M_{*} < 10^{8-9}\ {\rm M}_{\odot}$, reproducing the critical mass scale observed. However, for canonical values of the circumgalactic medium density ($n_{\rm halo} < 10^{-3.5}$${\rm cm}^{-3}$), we find that stripping is not fully effective; infalling satellites are, on average, stripped of < 40 - 70% of their cold gas reservoir, which is insufficient to match observations. By including a host halo gas distribution that is clumpy and therefore contains regions of higher density, we are able to reproduce the observed HI gas fractions (and thus the high quenched fraction and short quenching timescale) of Local Group satellites, suggesting that a host halo with clumpy gas may be crucial for quenching low-mass systems in Local Group-like (and more massive) host halos.Comment: updated version after review, now accepted to MNRAS; Accepted 2016 August 22. Received 2016 August 18; in original form 2016 June 2

Uncoupling protein-2 increases nitric oxide production and TNFAIP3 pathway activation in pancreatic islets

Mutations in the uncoupling protein 2 (Ucp2) gene are linked to type-2 diabetes. Here, a potential mechanism by which lack of UCP2 is cytoprotective in pancreatic β-cells was investigated. Nitric oxide (NO) production was elevated in Ucp2−/− islets. Proliferation (cyclin D2, Ccnd2) and anti-apoptosis (Tnfaip3) genes had increased expression in Ucp2−/− islets, whereas the mRNA of pro-apoptosis genes (Jun, Myc) was reduced. TNFAIP3 cellular localization was detected in both α- and β-cells of Ucp2−/− islets but in neither α- nor β-cells of UCP2+/+ islets, where it was detected in pancreatic polypeptide-expressing cells. TNFAIP3 distribution was not markedly altered 14 days after streptozotocin treatment. Basal apoptosis was attenuated in Ucp2−/− β-cells, while the nuclear factor κB (NF-κB) pathway was transactivated after islet isolation. Ucp2+/+ and Ucp2−/− islets were treated with cytokines for 24 h. Cytokines did not increase NF-κB transactivation or apoptosis in Ucp2−/− islets and TNFAIP3 was more strongly induced in Ucp2−/− islets. Inhibition of NO production strongly reduced NF-κB activation and apoptosis. These data show that null expression of Ucp2 induces transactivation of NF-κB in isolated islets, possibly due to NO-dependent up-regulation of inhibitor of κB kinase β activity. NF-κB transactivation appears to result in altered expression of genes that enhance a pro-survival phenotype basally and when β-cells are exposed to cytokines. TNFAIP3 is of particular interest because of its ability to regulate NF-κB signaling pathways

Body Segment Differences in Surface Area, Skin Temperature and 3D Displacement and the Estimation of Heat Balance during Locomotion in Hominins

The conventional method of estimating heat balance during locomotion in humans and other hominins treats the body as an undifferentiated mass. This is problematic because the segments of the body differ with respect to several variables that can affect thermoregulation. Here, we report a study that investigated the impact on heat balance during locomotion of inter-segment differences in three of these variables: surface area, skin temperature and rate of movement. The approach adopted in the study was to generate heat balance estimates with the conventional method and then compare them with heat balance estimates generated with a method that takes into account inter-segment differences in surface area, skin temperature and rate of movement. We reasoned that, if the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement affect heat balance during locomotion is correct, the estimates yielded by the two methods should be statistically significantly different. Anthropometric data were collected on seven adult male volunteers. The volunteers then walked on a treadmill at 1.2 m/s while 3D motion capture cameras recorded their movements. Next, the conventional and segmented methods were used to estimate the volunteers' heat balance while walking in four ambient temperatures. Lastly, the estimates produced with the two methods were compared with the paired t-test. The estimates of heat balance during locomotion yielded by the two methods are significantly different. Those yielded by the segmented method are significantly lower than those produced by the conventional method. Accordingly, the study supports the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement impact heat balance during locomotion. This has important implications not only for current understanding of heat balance during locomotion in hominins but also for how future research on this topic should be approached

The no-spin zone: rotation vs dispersion support in observed and simulated dwarf galaxies

We perform a systematic Bayesian analysis of rotation vs. dispersion support (v_(rot)/σ) in 40 dwarf galaxies throughout the Local Volume (LV) over a stellar mass range 10^(3.5) M_⊙ < M⋆ < 10^8 M_⊙. We find that the stars in ∼90% of the LV dwarf galaxies studied -- both satellites and isolated systems -- are dispersion-supported. In particular, we show that 7/10 *isolated* dwarfs in our sample have stellar populations with v_(rot)/σ<0.6. All have v_(rot)/σ≲2. These results challenge the traditional view that the stars in gas-rich dwarf irregulars (dIrrs) are distributed in cold, rotationally-supported stellar disks, while gas-poor dwarf spheroidals (dSphs) are kinematically distinct in having dispersion-supported stars. We see no clear trend between v_(rot)/σ and distance to the closest L⋆ galaxy, nor between v_(rot)/σ and M⋆ within our mass range. We apply the same Bayesian analysis to four FIRE hydrodynamic zoom-in simulations of isolated dwarf galaxies (10^9M⊙<M_(vir)<10^(10)M⊙) and show that the simulated *isolated* dIrr galaxies have stellar ellipticities and stellar v_(rot)/σ ratios that are consistent with the observed population of dIrrs *and* dSphs without the need to subject these dwarfs to any external perturbations or tidal forces. We posit that most dwarf galaxies form as puffy, dispersion-supported systems, rather than cold, angular momentum-supported disks. If this is the case, then transforming a dIrr into a dSph may require little more than removing its gas

Surface Transitions for Confined Associating Mixtures

Thin films of binary mixtures that interact through isotropic forces and directionally specific "hydrogen bonding" are considered through Monte Carlo simulations. We show, in good agreement with experiment, that the single phase of these mixtures can be stabilized or destabilized on confinement. These results resolve a long standing controversy, since previous theories suggest that confinement only stabilizes the single phase of fluid mixtures.Comment: LaTeX document, documentstyle[aps,preprint]{revtex}, psfig.sty, bibtex, 13 pages, 4 figure

Why Wait Until Our Community Gets Cancer?: Exploring CRC Screening Barriers and Facilitators in the Spanish-Speaking Community in North Carolina

Colorectal cancer (CRC) is a leading cause of death among Hispanics in the United States. Despite the benefits of CRC screening, many Hispanics are not being screened. Using a combined methodology of focus groups and discrete choice experiment (DCE) surveys, the objectives for this research were as follows: (1) to improve understanding of preferences regarding potential CRC screening program characteristics, and (2) to improve understanding of the barriers and facilitators around CRC screening with the Hispanic, immigrant community in North Carolina. Four gender-stratified focus groups were conducted and DCE surveys were administered to 38 Spanish-speaking individuals across four counties in North Carolina. In-depth content analysis was used to examine the focus group data; descriptive analyses and mean attribute importance scores for cost of screening and follow-up care, travel time, and test options were calculated from DCE data. Data analyses showed that this population has a strong interest in CRC screening but experience barrier such as lack of access to resources, cost uncertainty, and stigma. Some of these barriers are unique to their cultural experiences in the United States, such as an expressed lack of tailored CRC information. Based on the DCE, cost variables were more important than testing options or travel time. This study suggests that Hispanics may have a general awareness of and interest in CRC screening, but multiple barriers prevent them from getting screened. Special attention should be given to designing culturally and linguistically appropriate programs to improve access to healthcare resources, insurance, and associated costs among Hispanics