From Gatekeeping to Engagement: A Multicontextual, Mixed Method Study of Student Academic Engagement in Introductory STEM Courses.

The lack of academic engagement in introductory science courses is considered by some to be a primary reason why students switch out of science majors. This study employed a sequential, explanatory mixed methods approach to provide a richer understanding of the relationship between student engagement and introductory science instruction. Quantitative survey data were drawn from 2,873 students within 73 introductory science, technology, engineering, and mathematics (STEM) courses across 15 colleges and universities, and qualitative data were collected from 41 student focus groups at eight of these institutions. The findings indicate that students tended to be more engaged in courses where the instructor consistently signaled an openness to student questions and recognizes her/his role in helping students succeed. Likewise, students who reported feeling comfortable asking questions in class, seeking out tutoring, attending supplemental instruction sessions, and collaborating with other students in the course were also more likely to be engaged. Instructional implications for improving students' levels of academic engagement are discussed

Smart ophthalmics: the future in tele-ophthalmology has arrived

Smart Ophthalmics^© extends ophthalmic healthcare to people who operate/live in austere environments (e.g., military, third world, natural disaster), or are geographically dispersed (e.g., rural populations), where time, cost, and the possibility of travel/transportation make access to even adequate medical care difficult, if at all possible. Operators attach optical devices that act as ophthalmic examination extensions to smartphones and run custom apps to perform examinations of specific areas of the eye. The smartphone apps submit over wireless networks the collected examination data to a smart remote expert system, which provides in-depth medical analyses that are sent back in near real-time to the operators for subsequent triage

Density currents in the Chicago River : characterization, effects on water quality, and potential sources

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Science of The Total Environment 401 (2008): 130-143, doi:10.1016/j.scitotenv.2008.04.011.Bidirectional flows in a river system can occur under stratified flow conditions and in addition to creating significant errors in discharge estimates, the upstream propagating currents are capable of transporting contaminants and affecting water quality. Detailed field observations of bidirectional flows were made in the Chicago River in Chicago, Illinois in the winter of 2005-06. Using multiple acoustic Doppler current profilers simultaneously with a water-quality profiler, the formation of upstream propagating density currents within the Chicago River both as an underflow and an overflow was observed on three occasions. Density differences driving the flow primarily arise from salinity differences between intersecting branches of the Chicago River, whereas water temperature is secondary in the creation of these currents. Deicing salts appear to be the primary source of salinity in the North Branch of the Chicago River, entering the waterway through direct runoff and effluent from a wastewater-treatment plant in a large metropolitan area primarily served by combined sewers. Water-quality assessments of the Chicago River may underestimate (or overestimate) the impairment of the river because standard water-quality monitoring practices do not account for density-driven underflows (or overflows). Chloride concentrations near the riverbed can significantly exceed concentrations at the river surface during underflows indicating that full-depth parameter profiles are necessary for accurate water-quality assessments in urban environments where application of deicing salt is common.The authors greatly appreciate the support provided by USGS, Office of Surface Water (Hydroacoustics Program), the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC), the USGS Illinois Water Science Center

Monitoring the Petermann Ice Island with TanDEM-X

This paper presents the processing of TanDEM-X acquisitions for the monitoring of the topography of the Petermann ice island. In this particular case the area under study is continuously moving and the acquisition geometry is changing, so the processing of the iceberg’s DEMs is challenging and additional effects are to be considered. The SAR processing chain used is presented and the results obtained summarized, showing the effects and limitations observed during the process

Arsenosugar phospholipids and arsenic hydrocarbons in two species of brown macroalgae

Fourteen arsenolipids, including 11 new compounds, were identified and quantified in two species of brown algae, Wakame (Undaria pinnatifida) and Hijiki (Hizikia fusiformis), by high resolution mass spectrometry, high performance liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. Both algal species contained arsenosugar-phospholipids as the major type of arsenolipid, and arsenic-hydrocarbons were also significant components, particularly in Hijiki. The origin of the various arsenolipids, and the possible significance of their relative quantities, is briefly discussed

Tat-SF1 Is Not Required for Tat Transactivation but Does Regulate the Relative Levels of Unspliced and Spliced HIV-1 RNAs

.To directly address the involvement of Tat-SF1 in HIV-1 gene expression, we depleted Tat-SF1 in HeLa cells by conventional expression of shRNAs and in T- Rex -293 cells containing tetracycline-inducible shRNAs targeting Tat-SF1. We achieved efficient depletion of Tat-SF1 and demonstrated that this did not affect cell viability. HIV-1 infectivity decreased in Tat-SF1-depleted cells, but only when multiple rounds of infection occurred. Neither Tat-dependent nor basal transcription from the HIV-1 LTR was affected by Tat-SF1 depletion, suggesting that the decrease in infectivity was due to a deficiency at a later step in the viral lifecycle. Finally, Tat-SF1 depletion resulted in an increase in the ratio of unspliced to spliced viral transcripts.Tat-SF1 is not required for regulating HIV-1 transcription, but is required for maintaining the ratios of different classes of HIV-1 transcripts. These new findings highlight a novel, post-transcriptional role for Tat-SF1 in the HIV-1 life cycle

Determination of water and lipid-soluble arsenic compounds in the commercial edible seaweed Hijiki (Hizikia fusiforme)

Se presentan los resultados obtenidos en los estudios de especiación de arsénico realizados sobre el alga comestible Hijiki. Los análisis se realizaron a través de métodos analíticos desarrollados en la UPM (España) y en la Universidad de Graz (Austria). La determinación de especies hidrosolubles se realizó mediante HPLC-(UV)-HG-AFS, previa extracción mediante MAE con agua desionizada. Por otro lado, la identificación y cuantificación de arsenolípidos se llevó a cabo mediante HPLC-ICPMS/ESMS, previa extracción con cloroformo:metanol y purificación mediante SPE

Smart ophthalmics: the future in tele-ophthalmology has arrived

Smart Ophthalmics^© extends ophthalmic healthcare to people who operate/live in austere environments (e.g., military, third world, natural disaster), or are geographically dispersed (e.g., rural populations), where time, cost, and the possibility of travel/transportation make access to even adequate medical care difficult, if at all possible. Operators attach optical devices that act as ophthalmic examination extensions to smartphones and run custom apps to perform examinations of specific areas of the eye. The smartphone apps submit over wireless networks the collected examination data to a smart remote expert system, which provides in-depth medical analyses that are sent back in near real-time to the operators for subsequent triage

Initial Jitter Analysis of Lynx, a Proposed Future Large Astrophysics Facility

Lynx is an X-Ray telescope large-mission concept for consideration in NASA's 2020 Astrophysics Decadal Survey. A conceptual structural design is evolving that leverages the success and lessons learned from Chandra and that takes into account unique needs of Lynx. Space optics systems require extreme stability. Any motion in-service (thermal effects, structural dynamics, etc.) impacts performance. An initial analysis was performed to predict the first-cut dynamic responses, jitter, at two selected points on the Lynx observatory. One point is on the Lynx X-ray Mirror Assembly (LMA) and the other, on the focal plane Integrated Science Instrument Module (ISIM). Relative motion between these two points was predicted along with vibration spectra. This information will be used in upcoming analyses of the LMA and the ISIM

Beyond "natural-disasters-are-not-natural": the work of state and nature after the 2010 earthquake in Chile

Since the 1970s, human ecologists, geographers, Marxian political economists and others have insisted that there is no such thing as a 'natural' disaster. This assertion opened a space not only for exploring socioeconomic conditions that render marginalized populations vulnerable to natural hazards, but also for the formation of a field, the political ecology of hazards. A few political ecologists further interrogated the idea of a natural disaster, asking how different notions of 'the natural' circulate in post-disaster politics and with what effects. This article extends the latter approach by documenting how interconnected categories of 'nature' and 'state' were mutually constituted by narratives of politicians and elites after Chile's 2010 earthquake and tsunami. Drawing on media reports, we identify three distinct pairings of state/nature: (1) nature as manageable and the state as manager; (2) nature as out of control and the state as a police state; and (3) nature as financial opportunity and the state as prudential. Influenced by socioeconomic and historical factors, these state/nature pairings contradicted and reinforced one another in the disaster's aftermath and were deployed to reinforce top-down—rather than democratic—strategies of post-disaster reconstruction. This case offers an unusual approach to disaster politics by tracing how entwined and power-laden categories of state and nature condition the governance of disaster reconstruction processes. Key words: disaster, state, nature, socionature, political ecology of hazards, media disaster, earthquake, Latin America, Chile, 27