Identifying features predictive of faculty integrating computation into physics courses

Computation is a central aspect of 21st century physics practice; it is used to model complicated systems, to simulate impossible experiments, and to analyze mountains of data. Physics departments and their faculty are increasingly recognizing the importance of teaching computation to their students. We recently completed a national survey of faculty in physics departments to understand the state of computational instruction and the factors that underlie that instruction. The data collected from the faculty responding to the survey included a variety of scales, binary questions, and numerical responses. We then used Random Forest, a supervised learning technique, to explore the factors that are most predictive of whether a faculty member decides to include computation in their physics courses. We find that experience using computation with students in their research, or lack thereof and various personal beliefs to be most predictive of a faculty member having experience teaching computation. Interestingly, we find demographic and departmental factors to be less useful factors in our model. The results of this study inform future efforts to promote greater integration of computation into the physics curriculum as well as comment on the current state of computational instruction across the United States

Shaped nozzles for cryogenic buffer gas beam sources

Cryogenic buffer gas beams are important sources of cold molecules. In this work we explore the use of a converging-diverging nozzle with a buffer-gas beam. We find that, under appropriate circumstances, the use of a nozzle can produce a beam with improved collimation, lower transverse temperatures, and higher fluxes per solid angle

Acute kidney injury: electronic alerts in primary care - findings from a large population cohort

Background: Electronic reporting of AKI has been used to aid early AKI recognition although its relevance to CA-AKI and primary care has not been described. Aims: We described the characteristics and clinical outcomes of patients with CA-AKI, and AKI identified in primary care (PC-AKI) through AKI e-Alerts. Design: A prospective national cohort study was undertaken to collect data on all e-alerts representing adult CA-AKI. Method: The study utilised the biochemistry based AKI electronic (e)-alert system that is established across the Welsh National Health Service. Results: 28.8% of the 22,723 CA-AKI e-alerts were classified as PC-AKI. Ninety-day mortality was 24.0% and lower for PC-AKI vs. non-primary care (non-PC) CA-AKI. Hospitalisation was 22.3% for PC-AKI and associated with greater disease severity, higher mortality, but better renal outcomes (non-recovery: 18.1% vs. 21.6%; progression of pre-existing CKD: 40.5% vs. 58.3%). 49.1% of PC-AKI had a repeat test within seven days, 42.5% between seven and ninety days, and 8.4% was not repeated within ninety days. There was significantly more non-recovery (24.0% vs. 17.9%) and progression of pre-existing CKD (63.3% vs. 47.0%) in patients with late repeated measurement of renal function compared to those with early repeated measurement of renal function. Conclusion: The data demonstrate the clinical utility of AKI e-alerts in primary care. We recommend that a clinical review, or referral together with a repeat measurement of renal function within seven days should be considered an appropriate response to AKI e-alerts in primary care

The Millennium Galaxy Catalogue: morphological classification and bimodality in the colour-concentration plane

Using 10 095 galaxies (B < 20 mag) from the Millennium Galaxy Catalogue, we derive B-band luminosity distributions and selected bivariate brightness distributions for the galaxy population. All subdivisions extract highly correlated sub-sets of the galaxy population which consistently point towards two overlapping distributions. A clear bimodality in the observed distribution is seen in both the rest-(u-r) colour and log(n) distributions. The rest-(u-r) colour bimodality becomes more pronounced when using the core colour as opposed to global colour. The two populations are extremely well separated in the colour-log(n) plane. Using our sample of 3 314 (B < 19 mag) eyeball classified galaxies, we show that the bulge-dominated, early-type galaxies populate one peak and the bulge-less, late-type galaxies occupy the second. The early- and mid-type spirals sprawl across and between the peaks. This constitutes extremely strong evidence that the fundamental way to divide the luminous galaxy population is into bulges and discs and that the galaxy bimodality reflects the two component nature of galaxies and not two distinct galaxy classes. We argue that these two-components require two independent formation mechanisms/processes and advocate early bulge formation through initial collapse and ongoing disc formation through splashback, infall and merging/accretion. We calculate the B-band luminosity-densities and stellar-mass densities within each subdivision and estimate that the z ~ 0 stellar mass content in spheroids, bulges and discs is 35 +/- 2 per cent, 18 +/- 7 and 47 +/- 7 per cent respectively. [Abridged]Comment: Accepted for publication in MNRAS, 23 pages, 17 figures. Comments welcome. MGC website is at: http://www.eso.org/~jliske/mgc

Strong pressure-energy correlations in van der Waals liquids

Strong correlations between equilibrium fluctuations of the configurational parts of pressure and energy are found in the Lennard-Jones liquid and other simple liquids, but not in hydrogen-bonding liquids like methanol and water. The correlations, that are present also in the crystal and glass phases, reflect an effective inverse power-law repulsive potential dominating fluctuations, even at zero and slightly negative pressure. In experimental data for supercritical Argon, the correlations are found to be approximately 96%. Consequences for viscous liquid dynamics are discussed.Comment: Phys. Rev. Lett., in pres

The Ursinus Weekly, May 16, 1938

College to confer two honorary degrees • Y\u27s invite students, profs to spring doggie roast • Loan fund established by Varsity Club • 110 couples dance Friday at May sports hop • Stoudt, Plunkett star in Mother\u27s Day play; pageant, dinner other Saturday activities • Glatfelter chosen to head men\u27s council • Ursinus gains victory over Penn on radio • McClure, Poling speak at two Sunday vespers • June issue of Lantern to feature commencement • Presenting the \u27sinus senior: a preview of the 1938 Ruby questionnaire • Works of contemporary Philadelphia painters displayed in exhibit • Bears trim Albright, Gettysburg in league tilts • Trackmen poor fifth in Lancaster meet • Records broken as school trackmen meet here • Peg Claflin installed as new WAA head • Power leads batsmen • Todt succeeds Bodley as Varsity Club leader • Curtain clubbers dine and dance in Norristown • Power elected president of pre-legal society • Laucks conducts current events quiz of IRC • Germantown boy awarded sixth open scholarshiphttps://digitalcommons.ursinus.edu/weekly/1900/thumbnail.jp

First Remote Sensing Observations of Trifluoromethane (HFC-23) in the Upper Troposphere and Lower Stratosphere

This work reports the first remote sensing measurements of atmospheric HFC-23 (CHF3) using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the Jet Propulsion Laboratory Mark IV (MkIV) balloon interferometer. A total of 8809 ACE occultations measured between 2004 and 2010 have been processed, along with 24 MkIV occultations measured between 1989 and 2007. ACE data (yearly averages over the 10-25 km altitude range) in the tropics/subtropics (40°S-40°N) reveal a trend of 4.0 ± 1.6% per year in the growth of HFC-23 for 2004-2009 (or 3.9 ± 1.2% per year for 2004-2010), slightly smaller than surface measurements from Cape Grim air archive samples over the same time period (4.7 ± 0.3% per year). The northern midlatitude and high-latitude MkIV data (averaged over the 10-25 km altitude range) indicate a growth rate of 5.8 ± 0.3% per year over the period 1989-2007 (5.3 ± 0.4% per year for just the midlatitude data), similar to the Cape Grim surface trend of 5.7 ± 0.1% per year over the same period. The absolute HFC-23 volume mixing ratios measured by ACE and MkIV in the upper troposphere/lower stratosphere are in good agreement (\u3c5% bias) with each other but are ∼30% larger than ground-based measurements. The source of this bias has not been definitively ascertained; however, spectroscopic errors are the most likely cause. Copyright 2012 by the American Geophysical Union

Nucleosome dynamics of human iPSC during neural differentiation

Nucleosome positioning is important for neurodevelopment, and genes mediating chromatin remodelling are strongly associated with human neurodevelopmental disorders. To investigate changes in nucleosome positioning during neural differentiation, we generate genome‐wide nucleosome maps from an undifferentiated human‐induced pluripotent stem cell (hiPSC) line and after its differentiation to the neural progenitor cell (NPC) stage. We find that nearly 3% of nucleosomes are highly positioned in NPC, but significantly, there are eightfold fewer positioned nucleosomes in pluripotent cells, indicating increased positioning during cell differentiation. Positioned nucleosomes do not strongly correlate with active chromatin marks or gene transcription. Unexpectedly, we find a small population of nucleosomes that occupy similar positions in pluripotent and neural progenitor cells and are found at binding sites of the key gene regulators NRSF/REST and CTCF. Remarkably, the presence of these nucleosomes appears to be independent of the associated regulatory complexes. Together, these results present a scenario in human cells, where positioned nucleosomes are sparse and dynamic, but may act to alter gene expression at a distance via the structural conformation at sites of chromatin regulation