Learning from television: a study of the effects of different levels of explicitness and the influence of spatial ability on learning of visual concepts and principles

This study explored the effects of the degree of exphcitness used to show movement and manipulation in teaching visual concepts through television. The review of the relevant theories highlighted the importance of individual differences in cognitive processing skills. The research question was formulated in terms of an aptitude treatment interaction. The aptitude of spatial ability was expected to interact with the level of exphcitness of moving visual sequences. A sample of 200 school children were divided into a control and two treatment groups Spatial ability was measured using a paper-folding test. The two television treatments, explicit and implicit, varied as to the degree of movement used to illustrate visual concepts and processes. An immediate comprehension test revealed no differences between the treatment groups. A test of retention administered three weeks later, showed a significant difference in favour of the explicit group Spatial ability was shown to be a significant moderating variable on both tests. No interaction between the variables was found

Pasteurella multocida Bacteremia in a Patient With Ovarian Cancer and Chemotherapy-induced Neutropenia

Background: Pasteurella multocida is a commensal organism found in the saliva and oropharynx of domestic animals. It causes a variety of human infections ranging from cellulitis to bacteremia and sepsis. The severity of infection is somewhat related to the immunocompetency of the infected host. An immunocompromised host is more likely to suffer a disseminated infection as a result of contact with this organism than an immunocompetent host. This case report and review of the literature are presented to further evaluate the types of infections caused by this organism in oncology patients

The impact of third places on community quality of life

Older cities struggling with issues of survival focus on jobs and the economy, but competition requires all cities to pay attention to the quality of life that attracts residents. Creating such an inviting environment includes “third places” that foster community and communication among people outside of home and work, yet we have little empirical evidence that speaks to the subject, or their importance for a community’s quality of life. Here we report on a national U.S. survey that asked people to identify such places in their community, producing a wide variety of “third places” that ranged from the most popular community centers, coffee shops and restaurants to parks and malls. While a few relationships are found between population/diversity and the popularity of particular third places, the most important result confirms a hypothesized relationship between perceptions that third places are accessible in their community and the perceived quality of life

The Intrinsic Two-Dimensional Size of Sagittarius A*

We report the detection of the two-dimensional structure of the radio source associated with the Galactic Center black hole, Sagittarius A*, obtained from Very Long Baseline Array (VLBA) observations at a wavelength of 7mm. The intrinsic source is modeled as an elliptical Gaussian with major axis size 35.4 x 12.6 R_S in position angle 95 deg East of North. This morphology can be interpreted in the context of both jet and accretion disk models for the radio emission. There is supporting evidence in large angular-scale multi-wavelength observations for both source models for a preferred axis near 95 deg. We also place a maximum peak-to-peak change of 15% in the intrinsic major axis size over five different epochs. Three observations were triggered by detection of near infrared (NIR) flares and one was simultaneous with a large X-ray flare detected by NuSTAR. The absence of simultaneous and quasi-simultaneous flares indicates that not all high energy events produce variability at radio wavelengths. This supports the conclusion that NIR and X-ray flares are primarily due to electron excitation and not to an enhanced accretion rate onto the black hole.Comment: accepted for publication in Ap

Breaking Barriers to Low-Cost Modular Inverter Production & Use

The goal of this cost share contract is to advance key technologies to reduce size, weight and cost while enhancing performance and reliability of Modular Inverter Product for Distributed Energy Resources (DER). Efforts address technology development to meet technical needs of DER market protection, isolation, reliability, and quality. Program activities build on SatCon Technology Corporation inverter experience (e.g., AIPM, Starsine, PowerGate) for Photovoltaic, Fuel Cell, Energy Storage applications. Efforts focused four technical areas, Capacitors, Cooling, Voltage Sensing and Control of Parallel Inverters. Capacitor efforts developed a hybrid capacitor approach for conditioning SatCon's AIPM unit supply voltages by incorporating several types and sizes to store energy and filter at high, medium and low frequencies while minimizing parasitics (ESR and ESL). Cooling efforts converted the liquid cooled AIPM module to an air-cooled unit using augmented fin, impingement flow cooling. Voltage sensing efforts successfully modified the existing AIPM sensor board to allow several, application dependent configurations and enabling voltage sensor galvanic isolation. Parallel inverter control efforts realized a reliable technique to control individual inverters, connected in a parallel configuration, without a communication link. Individual inverter currents, AC and DC, were balanced in the paralleled modules by introducing a delay to the individual PWM gate pulses. The load current sharing is robust and independent of load types (i.e., linear and nonlinear, resistive and/or inductive). It is a simple yet powerful method for paralleling both individual devices dramatically improves reliability and fault tolerance of parallel inverter power systems. A patent application has been made based on this control technology

ZFIRE: Measuring Electron Density with [OII] as a function of environment at z = 1.62

The global star formation rates (SFR) of galaxies at fixed stellar masses increase with redshift and are known to vary with environment unto z~2. We explore here whether the changes in the star formation rates can also apply to the electron densities of the inter-stellar medium (ISM) by measuring the [OII] (3727A/3729A) ratio for cluster and field galaxies at z~2. We measure a median electron density of ne = 366+/-84 cm-3 for six galaxies (with 1-sigma scatter = 163 cm-3) in the UDS proton-cluster at z=1.62. We find that the median electron density of galaxies in the UDS photo-cluster environment is three times higher compared to the median electron density of field galaxies (ne = 113+/- 63 cm-3 and 1-sigma scatter = 79 cm-3) at comparable redshifts, stellar mass and SFR. However, we note that a sample of six photo-cluster galaxies is insufficient to reliably measure the electron density in the average porto-cluster environment at z~2. We conclude that the electron density increases with redshift in both cluster and field environments up to z~2 (ne = 30 +/- 1 cm-3 for z ~ 0 to ne =254+/- 76 cm-3 for z~1.5). We find tentative evidence (~2.6 sigma ) for a possible dependence of electron density on environment, but the results require confirmation with larger sample sizes.Comment: 18 Pages, 6 figures, 3 tables, Accepted for publication in Astrophysical Journa

The Allen Telescope Array Pi GHz Sky Survey I. Survey Description and Static Catalog Results for the Bootes Field

The Pi GHz Sky Survey (PiGSS) is a key project of the Allen Telescope Array. PiGSS is a 3.1 GHz survey of radio continuum emission in the extragalactic sky with an emphasis on synoptic observations that measure the static and time-variable properties of the sky. During the 2.5-year campaign, PiGSS will twice observe ~250,000 radio sources in the 10,000 deg^2 region of the sky with b > 30 deg to an rms sensitivity of ~1 mJy. Additionally, sub-regions of the sky will be observed multiple times to characterize variability on time scales of days to years. We present here observations of a 10 deg^2 region in the Bootes constellation overlapping the NOAO Deep Wide Field Survey field. The PiGSS image was constructed from 75 daily observations distributed over a 4-month period and has an rms flux density between 200 and 250 microJy. This represents a deeper image by a factor of 4 to 8 than we will achieve over the entire 10,000 deg^2. We provide flux densities, source sizes, and spectral indices for the 425 sources detected in the image. We identify ~100$ new flat spectrum radio sources; we project that when completed PiGSS will identify 10^4 flat spectrum sources. We identify one source that is a possible transient radio source. This survey provides new limits on faint radio transients and variables with characteristic durations of months.Comment: Accepted for publication in ApJ; revision submitted with extraneous figure remove