21,505 research outputs found
After the SKA - Radio Astronomy in 2049
The concept of a Square Kilometre Array was developed to ensure that progress
in Radio Astronomy in the early 21st Century continued at the same impressive
pace as was achieved during the first 50 years. The SKA telescope is designed
to pave that road to greater and greater sensitivity. So what technical
challenges does the project face and what key innovations will drive the
success of the SKA? What will the next Radio Astronomy mega-science project
look like? In this article the author discusses the likely avenues of progress
in the coming decades and comments on the status of radio astronomy in 2049 -
the author's 70th (and presumably her retirement) year.Comment: Conference Proceedings PoS(RTS2012), 8 pages, 1 figur
High Spatial Resolution KAO Far-Infrared Observations of the Central Regions of Infrared-Bright Galaxies
We present new high spatial resolution Kuiper Airborne Observatory 50 micron
and/or 100 micron data for 11 infrared-bright galaxies. We also tabulate
previously published KAO data for 11 other galaxies, along with the IRAS data
for the bulges of M 31 and M 81. We find that L(FIR)/L(B) and L(FIR)/L(H)
correlate with CO (1 - 0) intensity and tau(100). Galaxies with optical or
near-infrared signatures of OB stars in their central regions have higher
values of I(CO) and tau(100), as well as higher far-infrared surface
brightnesses and L(FIR)/L(B) and L(FIR)/L(H) ratios. L(FIR)/L(H(alpha)) does
not correlate strongly with CO and tau(100). These results support a scenario
in which OB stars dominate dust heating in the more active galaxies and older
stars are important in quiescent bulges.Comment: 45 pages, to appear in Ap.J. vol. 468 (Sept. 1996). 17 postscript
figures and 10 postscript tables available at
ftp://ipac.caltech.edu/science/bsmith/ka
Middle and elementary school students’ changes in self-determined motivation in a basketball unit taught using the Tactical Games Model
Studies examining student motivation levels suggest that this is a significant factor in students’ engagement in physical education and may be positively affected when teachers employ alternative pedagogical models such as game-centered approaches (GCAs). The aim of this study was to investigate changes in self-determined motivation of students as they participated in a GCA-basketball unit taught using the Tactical Games Model (TGM). Participants were 173 students (84 girls), 79 middle school (45 girls) and 94 (39 girls) elementary school students from four seventh and five fourth/fifth grade co-educational classes. Two teachers taught 32 (middle) and 33 (elementary) level one TGM basketball lessons. Need satisfaction and self-determined motivation data were collected using a previously validated instrument, while lesson context and teacher behavior data were recorded using systematic observation instruments. Repeated measures MANOVAs were employed to examine pre-posttest differences. Results revealed a significant main effect for time in need satisfaction for both middle (relatedness increased) and elementary school students (autonomy decreased) and a significant main effect in self-determined motivation for middle school students only (introjected regulation, external regulation, and amotivation all increased). Approximately 48%/42% (middle/elementary) of lesson time was game play, 22%/22% skill practice, 17%/17% management, and 13%/19% knowledge. The primary teacher behaviors used were instruction, management, specific observation, corrective feedback and modelling. Results indicate that it is important for future research to pay greater attention to the contextual factors associated with the application of the TGM, such as the students’ previous exposure to TGM lessons, and the teachers’ training and experience in utilizing the TGM. Indeed, results of the present study demonstrate that a longer-term commitment to the TGM is necessary to reduce controlling teacher behaviors, which will lead to positive changes in students’ need satisfaction and self-determined motivation. Future research is therefore needed to embrace this challenge to provide an increased evidence-base for GCAs such as the TGM
Getting to Know Peasants: Local Population Records and Rural Society in Nineteenth-Century France
Inconsistent terminology and under-reporting of agricultural occupations in the
French manuscript census schedules from the nineteenth century has proved to be
a serious problem for historians. Drawing on the literature that discusses these
matters, this article presents evidence from a sample commune to propose a
solution: creating linked population files to construct a set oflongitudinal analytical
class groups into which specific occupations can be assigned in a variable way,
depending on standard criteria, from one census to the next. Several tests of social
data from local records using the analytical classifications are presented to
demonstrate their usefulness for social history.Une terminologie flottante et le sous-dénombrement des professions agricoles dans
les listes nominatives de recensement françaises du XIXe siècle ont considérablement
gêné les historiens dans leur travail. S'inspirant de la documentation sur le sujet,
le présent article en arrive à proposer une solution après étude d'une commune
échantillon: créer des fichiers de population enchaînés pour bâtir un ensemble de
catégories longitudinales et analytiques auxquelles on puisse assigner des
professions particulières de façon variable, suivant des critères standards, d'un
recensement à l'autre. Plusieurs tests de données sociales tirées de registres locaux
faits au moyen des classifications analytiques sont présentés afin de démontrer leur
utilité pour l'histoire sociale
Gender and school-level differences in students' moderate and vigorous physical activity levels when taught basketball through the tactical games model
The Tactical Games Model (TGM) prefaces the cognitive components of physical education (PE), which has implications for physical activity (PA) accumulation. PA recommendations suggest students reach 50% moderate-vigorous physical activity (MVPA). However, this criterion does not indicate the contribution from vigorous physical activity (VPA). Consequently, this study investigated: a) the effects of TGM delivery on MVPA/VPA and, b) gender/school level differences. Participants were 78 seventh and 96 fourth/fifth grade coeducational PE students from two different schools. Two teachers taught 24 (middle) and 30 (elementary) level one TGM basketball lessons. Students wore Actigraph GT3Ă— triaxial accelerometers. Data were analyzed using four one-way ANOVAs. Middle school boys had significantly higher MVPA/VPA (34.04/22.37%) than girls (25.14/15.47%). Elementary school boys had significantly higher MVPA/VPA (29.73/18.33%) than girls (23.03/14.33%). While TGM lessons provide a context where students can accumulate VPA consistent with national PA recommendations, teachers need to modify lesson activities to enable equitable PA participation
Electric field enhancement of efficiency in autoradiographic exposures
An external electric field was applied during autoradiographic exposures in an attempt to influence the path length and trajectory of image forming beta particles. Various techniques were employed to maximize the electric field applied. No evidence was found for increases in efficiency of image formation within the receiving emulsion, up to a field strength of 7 x 10 volts/cm
One year of monitoring the Vela pulsar using a Phased Array Feed
We have observed the Vela pulsar for one year using a Phased Array Feed (PAF)
receiver on the 12-metre antenna of the Parkes Test-Bed Facility. These
observations have allowed us to investigate the stability of the PAF
beam-weights over time, to demonstrate that pulsars can be timed over long
periods using PAF technology and to detect and study the most recent glitch
event that occurred on 12 December 2016. The beam-weights are shown to be
stable to 1% on time scales on the order of three weeks. We discuss the
implications of this for monitoring pulsars using PAFs on single dish
telescopes.Comment: 6 pages, 4 figures, 2 tables. Accepted for publication in PAS
High spatial resolution 100 micron observations of the M83 bar
A program of high spatial resolution far-infrared observations of galaxies using the Kuiper Airborne Observatory (KAO), was conducted to better understand the role of star formation, the general interstellar radiation field, and non-thermal activity in powering the prodigious far-infrared luminosities seen in spiral and interacting galaxies. Here, researchers present observations of the central region of the well-known barred spiral M83 (NGC 5236). The resultant channel 3 scans for M83 and IRC + 10216, after co-addition and smoothing, are shown. These data show that M83 is extended at 100 microns compared to a point source. A simple Gaussian deconvolution of the M83 data with the point source profile from IRC+10216 gives a full width half maximum (FWHM) of about 19 seconds for M83. By comparison with IRC+10216, researchers obtain a flux for the unresolved component in M83 of about 110 Jy. This is about 1/6 the total flux for M83 (Rice et al. 1988) and about 1/2 the PSC flux. The M83 and IRC+10216 profiles in the cross-scan direction (SE-NW) were also compared, and show that M83 is extended in this direction as well, with a width of about 18 seconds. A comparison of the different channel profiles for M83 and IRC+10216 shows that there is an asymmetry in the M83 data, in that the maximum in the profiles shifts from southeast to northwest as channel number increases. This corresponds to the extension in the bar seen in the CO data. Thus the far-infrared emission in the central region of M83 tends to trace the CO bar. The new 100 micron data is also compared with previous H alpha observations from the literature, to determine how well the far-infrared traces the stellar structure, the star formation as measured by H alpha, and the optical colors
Promoting equity in STEM classrooms
This keynote, delivered by Professor Lisa Harvey-Smith, will outline the current state of play for women and girls’ participation in STEM, and consider how staff in universities can contribute to achieving greater equity in STEM subjects. Professor Harvey-Smith is the Australian Government’s Women in STEM Ambassador and a Professor of Practice at the University of New South Wales. In her role, Lisa and her team work to cultivate the conditions in which all Australians can pursue successful and rewarding careers in STEM. The work of the Ambassador’s Office includes: providing expert advice to policy makers, peak bodies, and other stakeholders; education and outreach through the Future You national awareness raising initiative; as well as contributing to current research into equitable STEM participation and evidence-based practices to improve participation, engagement and outcomes for diverse students
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