246 research outputs found
Self-Concept in Children and Adolescents as A Lever for Change in Academic Success for Under-Served Youth
Children and adolescents in under-resourced urban communities simultaneously experience higher rates of major life stressors, including mental health problems, and less access to the services needed to address these concerns. The combination of high need and few resources makes identifying broadly effective, resource-minimal interventions a critical goal. Amongst potential targets for intervention, academic success, particularly graduating from high school, predicts positive life outcomes across a wide range of health factors. To be effective in supporting academic success in under-served communities, an intervention must be universally applicable, inexpensive, and easy to deliver with fidelity. The current study examined the promise of self-concept as a potential lever for change in academic success for underserved youth. Beginning with an examination of the proposed theoretical model, which suggests that changes in non-academic self-concept in children and teens can lead to improved academic outcomes by improving academic self-concept and reducing mental health symptoms, the study then reports the findings of a randomized controlled trial testing a self-guided journal writing intervention targeting non-academic self-concept for students in a diverse, under-resourced urban high school. vii The intervention was delivered as a classroom assignment, and 89 9th grade students consented to provide academic data (75 also agreed to provide self-report data) and were randomized to the intervention or an active control condition. Findings did not indicate a significant effect of the intervention on student GPA at the end of the academic year; however, evidence for the validity of the theoretical model emerged. Thus, the current study offers implications for future research and intervention design targeting under served adolescents in urban high schools
The Jesse Kirk Button Belt
https://scholarcommons.sc.edu/archanth_books/1131/thumbnail.jp
Optimal Point-Source Extraction for Spitzer IRS Spectra
A new optimal-extraction technique has been developed for deriving point-source spectra from data taken by the Infrared Spectrograph (IRS) on-board the Spitzer Space Telescope. The new technique gives improvements of up to a factor of two in the signal-to-noise ratio (S/N) for faint (< 10 mJy) sources, corresponding to an effective quadrupling of the exposure time. Regular extraction consists of an even-weighted summing of pixel values at the same wavelength. Optimal extraction weights each pixel by its S/N, estimated using the spatial profile of a bright calibration star and data uncertainties. Additionally,
the optimal-extraction calculations are performed in “rectified” space, and so a natural by-product of the processing is a useful output file containing the
rectified image. The optimal-extraction technique is unsuitable for extended sources and best only for point sources
Space Station CMIF extended duration metabolic control test
The Space Station Extended Duration Metabolic Control Test (EMCT) was conducted at the MSFC Core Module Integration Facility. The primary objective of the EMCT was to gather performance data from a partially-closed regenerative Environmental Control and Life Support (ECLS) system functioning under steady-state conditions. Included is a description of the EMCT configuration, a summary of events, a discussion of anomalies that occurred during the test, and detailed results and analysis from individual measurements of water and gas samples taken during the test. A comparison of the physical, chemical, and microbiological methods used in the post test laboratory analyses of the water samples is included. The preprototype ECLS hardware used in the test, providing an overall process description and theory of operation for each hardware item. Analytical results pertaining to a system level mass balance and selected system power estimates are also included
Cygnus A Obscuring Torus: Ionized, Atomic or Molecular?
The prototypical powerful FR \Romannum{2} radio galaxy Cygnus A fits
extremely well into the quasar/radio galaxy unified model: high polarization
with an angle almost perpendicular to the radio jet and polarized flux showing
broad permitted lines. It has been claimed that ionized gas in the torus
reveals a very clear torus shape via Bremmstrahlung emission. We rule out the
later with an energetic argument, and we constrain the molecular and atomic gas
properties with existing observations. The atomic absorption against the core
has been shown to match the X-ray column only if the spin temperature is an
implausible K. This points to a molecular medium for
the X-ray column . Yet not low-J CO
absorption is detected to sensitive limits. The non-detection is surprising
given that this powerful radio galaxy hosts a luminous, dust-obscured active
nucleus and copious warm molecular hydrogen. These conditions suggest a
detectable level of emission. Furthermore, the torus X-ray column density
suggests detectable absorption. We explore various possibilities to explain the
lack of a signature from warm CO (200-250K). Specifically, that the radiative
excitation by the radio core renders low-J CO absorption below current
sensitivities, and that high-J levels are well populated and conducive to
producing absorption. We test this hypothesis using archival
\textit{Hershel}/SPIRE FTS observations of Cygnus A of high-J CO lines ( transitions). Still high-J CO lines are not detected. We suggest
that ALMA observations near its high frequency limit can be critical to obtain
the signature of molecular line of the torus of Cygnus A
Gas producer tests with varying sizes of fuel
Thesis (BS)--University of Illinois, 1913TypescriptThe non-folded leaf of plates is numbered as "1a
Jet-Powered Molecular Hydrogen Emission from Radio Galaxies
H2 pure-rotational emission lines are detected from warm (100-1500 K)
molecular gas in 17/55 (31% of) radio galaxies at redshift z<0.22 observed with
the Spitzer IR Spectrograph. The summed H2 0-0 S(0)-S(3) line luminosities are
L(H2)=7E38-2E42 erg/s, yielding warm H2 masses up to 2E10 Msun. These radio
galaxies, of both FR radio morphological types, help to firmly establish the
new class of radio-selected molecular hydrogen emission galaxies (radio
MOHEGs). MOHEGs have extremely large H2 to 7.7 micron PAH emission ratios:
L(H2)/L(PAH7.7) = 0.04-4, up to a factor 300 greater than the median value for
normal star-forming galaxies. In spite of large H2 masses, MOHEGs appear to be
inefficient at forming stars, perhaps because the molecular gas is
kinematically unsettled and turbulent. Low-luminosity mid-IR continuum emission
together with low-ionization emission line spectra indicate low-luminosity AGNs
in all but 3 radio MOHEGs. The AGN X-ray emission measured with Chandra is not
luminous enough to power the H2 emission from MOHEGs. Nearly all radio MOHEGs
belong to clusters or close pairs, including 4 cool core clusters (Perseus,
Hydra, A 2052, and A 2199). We suggest that the H2 in radio MOHEGs is delivered
in galaxy collisions or cooling flows, then heated by radio jet feedback in the
form of kinetic energy dissipation by shocks or cosmic rays.Comment: ApJ in press, 40 pages, 18 figures, 14 table
Shocked Molecular Hydrogen in the 3C 326 Radio Galaxy System
The Spitzer spectrum of the giant FR II radio galaxy 3C 326 is dominated by
very strong molecular hydrogen emission lines on a faint IR continuum. The H2
emission originates in the northern component of a double-galaxy system
associated with 3C 326. The integrated luminosity in H2 pure-rotational lines
is 8.0E41 erg/s, which corresponds to 17% of the 8-70 micron luminosity of the
galaxy. A wide range of temperatures (125-1000 K) is measured from the H2 0-0
S(0)-S(7) transitions, leading to a warm H2 mass of 1.1E9 Msun. Low-excitation
ionic forbidden emission lines are consistent with an optical LINER
classification for the active nucleus, which is not luminous enough to power
the observed H2 emission. The H2 could be shock-heated by the radio jets, but
there is no direct indication of this. More likely, the H2 is shock-heated in a
tidal accretion flow induced by interaction with the southern companion galaxy.
The latter scenario is supported by an irregular morphology, tidal bridge, and
possible tidal tail imaged with IRAC at 3-9 micron. Unlike ULIRGs, which in
some cases exhibit H2 line luminosities of comparable strength, 3C 326 shows
little star-formation activity (~0.1 Msun/yr). This may represent an important
stage in galaxy evolution. Starburst activity and efficient accretion onto the
central supermassive black hole may be delayed until the shock-heated H2 can
kinematically settle and coolComment: 27 pages, 7 figures, accepted for publication in the Astrophysical
Journa
The Characterization of Ribosomal RNA Gene Chromatin from Physarum Polycephalum
We have isolated ribosomal RNA gene (rDNA) chromatin from Physarum polycephalum using a nucleolar isolation procedure that minimizes protein loss from chromatin and, subsequently, either agarose gel electrophoresis or metrizamide gradient centrifugation to purify this chromatin fraction (Amero, S. A., Ogle, R. C., Keating, J. L., Montoya, V. L., Murdoch, W. L., and Grainger, R. M. (1988) J. Biol. Chem. 263, 10725-10733). Metrizamide-purified rDNA chromatin obtained from nucleoli isolated according to the new procedure has a core histone/DNA ratio of 0.77:1. The major core histone classes comigrate electrophoretically with their nuclear counterparts on Triton-acid-urea/sodium dodecyl sulfate two-dimensional gels, although they may not possess the extent of secondary modification evident with the nuclear histones. This purified rDNA chromatin also possesses RNA polymerase I activity, and many other nonhistone proteins, including two very abundant proteins (26 and 38 kDa) that may be either ribonucleoproteins or nucleolar matrix proteins. Micrococcal nuclease digestion of the metrizamide-purified rDNA chromatin produces particles containing 145-base pair DNA fragments identical in length to those in total chromatin and which contain both transcribed and nontranscribed rDNA sequences. Some smaller fragments (30, 70, and 110 base pairs) are also seen, but their sequence content is not known. These particles sediment uniformly at 11 S in sucrose gradients containing 15 mM NaCl, and at 4-11 S in gradients containing 0.35 M NaCl. Particles enriched in gene or nontranscribed spacer sequences are not resolved in these sucrose gradients or in metrizamide gradients. Our findings suggest that the rDNA chromatin fraction we have identified contains transcriptionally active genes and that an organized, particle-containing structure exists in active rDNA chromatin
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