9 research outputs found
A comparative appraisal of some community-based alternatives to institutionalization
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44037/1/10464_2004_Article_BF00878045.pd
A Comparison of Water Chemistry and Bacterial Abundance In Urban and Rural Streams at Similar Elevations In the South Carolina Piedmont
Land development and increasing population density in watershed areas has been shown to decrease water quality. We sought to determine the influence of urban development on water quality. To do this, we compared urban and rural streams in 1 to 10 km2 watersheds at similar elevations (240-300 m) in the upper Piedmont of South Carolina. Impervious surface cover was 21-52% in urban watersheds and only 0.2-1% in rural watersheds. We hypothesized that bacterial abundance and concentrations of major cations (i.e. Na, Fe, K, Ca, Si, Mg) would be higher in urban than rural streams due to possible influences of urban development as previous studies have suggested. Working from their conclusions, we tested our hypothesis by measuring pH, dissolved oxygen (DO), conductivity, water temperature, and stream discharge. In addition, we collected water samples for chemical and bacterial analyses. Analysis of ammonium, dissolved organic carbon (DOC), and bacterial concentrations (i.e. total coliforms, Escherichia coli, enterococci, and total heterotrophs) revealed that urban streams had higher concentrations of measured cations and anions and more than double the mean DOC concentration than that of rural streams. Similarly, bacterial populations were higher in urban than rural streams. Our results are consistent with previous studies, suggesting urban infrastructure (e.g. impervious surfaces, leaking sewer lines, and concrete drainage structures) can degrade the quality of water urban streams. Future studies are needed to determine which types of infrastructure have the strongest influences on water quality in urban streams
PRIMALung (EORTC-1901-LCG): prophylactic cerebral irradiation or active brain magnetic resonance imaging surveillance in small-cell lung cancer patients
A program evaluation of a juvenile halfway house: considerations for strengthening program components
This article reports the program evaluation findings of a male juvenile halfway house. An analysis of three program aspects is provided: (a) program components, (b) a review of closed resident records, and (c) Department of Juvenile Justice program indicators. Using 101 cases, a juvenile offender descriptive profile is presented as an important ingredient for interpreting program needs and focus. Using existing literature, the program is compared to other similar juvenile halfway houses. Recommendations are made for future practice and program evaluation in this area. © 1999 Elsevier Science Ltd
Coronal Heating as Determined by the Solar Flare Frequency Distribution Obtained by Aggregating Case Studies
Flare frequency distributions represent a key approach to addressing one of
the largest problems in solar and stellar physics: determining the mechanism
that counter-intuitively heats coronae to temperatures that are orders of
magnitude hotter than the corresponding photospheres. It is widely accepted
that the magnetic field is responsible for the heating, but there are two
competing mechanisms that could explain it: nanoflares or Alfv\'en waves. To
date, neither can be directly observed. Nanoflares are, by definition,
extremely small, but their aggregate energy release could represent a
substantial heating mechanism, presuming they are sufficiently abundant. One
way to test this presumption is via the flare frequency distribution, which
describes how often flares of various energies occur. If the slope of the power
law fitting the flare frequency distribution is above a critical threshold,
as established in prior literature, then there should be a
sufficient abundance of nanoflares to explain coronal heating. We performed
600 case studies of solar flares, made possible by an unprecedented number
of data analysts via three semesters of an undergraduate physics laboratory
course. This allowed us to include two crucial, but nontrivial, analysis
methods: pre-flare baseline subtraction and computation of the flare energy,
which requires determining flare start and stop times. We aggregated the
results of these analyses into a statistical study to determine that . This is below the critical threshold, suggesting that Alfv\'en
waves are an important driver of coronal heating.Comment: 1,002 authors, 14 pages, 4 figures, 3 tables, published by The
Astrophysical Journal on 2023-05-09, volume 948, page 7