876 research outputs found
Freshman learning communities, college performance, and retention
This paper applies a standard treatment effects model to determine that participation in Freshman Learning Communities (FLCs) improves academic performance and retention. Not controlling for individual self-selection into FLC participation leads one to incorrectly conclude that the impact is the same across race and gender groups. Accurately assessing the impact of any educational program is essential in determining what resources institutions should devote to it.
Characterising Testing Preorders for Finite Probabilistic Processes
In 1992 Wang & Larsen extended the may- and must preorders of De Nicola and
Hennessy to processes featuring probabilistic as well as nondeterministic
choice. They concluded with two problems that have remained open throughout the
years, namely to find complete axiomatisations and alternative
characterisations for these preorders. This paper solves both problems for
finite processes with silent moves. It characterises the may preorder in terms
of simulation, and the must preorder in terms of failure simulation. It also
gives a characterisation of both preorders using a modal logic. Finally it
axiomatises both preorders over a probabilistic version of CSP.Comment: 33 page
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Purpose in Life and Conscientiousness Protect Against the Development of Suicidal Ideation in U.S. Military Veterans With PTSD and MDD: Results From the National Health and Resilience in Veterans Study.
Background:Although several studies have examined risk factors for suicidal ideation among veterans, little is known about risk and protective factors for suicidal ideation in high-risk veteran samples. Thus, this study examined a broad range of risk and protective factors associated with the development of suicidal ideation in a high-risk sample of U.S. veterans who screened positive for current posttraumatic stress disorder (PTSD) and/or major depressive disorder (MDD). Methods:Data were analyzed from the National Health and Resilience in Veterans Study, a nationally representative, prospective cohort study of U.S. veterans. Veterans completed self-report measures to screen for PTSD and MDD and to assess for risk and protective factors. The sample included 222 veterans with PTSD and/or MDD who did not endorse suicidal ideation at baseline and completed at least one assessment over a seven-year follow-up period. A multivariable binary logistic regression analysis was conducted to examine baseline factors associated with incident suicidal ideation. Results:Nearly one in three (27.1%) of veterans with PTSD and/or MDD developed suicidal ideation over the seven-year follow-up period. Non-Caucasian race and lower scores on measures of purpose in life, conscientiousness, and frequency of religious service attendance were independently associated with incident suicidal ideation. Lower purpose in life (52.3%) and conscientiousness (33.2%) explained the vast majority of variance in incident suicidal ideation. Conclusion:Nearly 30% of veterans with PTSD and/or MDD who did not endorse suicidal ideation at baseline developed suicidal ideation over a seven-year period. Prevention and treatment efforts designed to bolster purpose in life and conscientiousness may help mitigate risk for suicidal ideation in this high-risk population
Two-dimensional Transonic Investigation of Flows and Forces on a 9-percent-thick Airfoil with 30-percent-chord Flap
Fly-By-Light/Power-By-Wire Requirements and Technology Workshop
The results of the Fly-By-Light/Power-By-Wire (FBL/PBW) Workshop held on March 17-19, 1992, at the NASA Langley Research Center are presented. The FBL/PBW program is a joint NASA LeRC/LaRC effort to develop the technology base for confident application of integrated FBL/PBW systems to transport aircraft. The objectives of the workshop were to ascertain the FBL/PBW program technical requirements and satisfy the requirements and needs from the industry viewpoint, provide a forum for presenting and documenting alternative technical approaches which satisfy the requirements, and assess the plan adequacy in accomplishing plan objectives, aims, and technology transfer. Areas addressed were: optical sensor systems, power-by-wire systems, FBL/PBW fault-tolerant architectures, electromagnetic environment assessment, and system integration and demonstration. The workshop consisted of an introductory meeting, a 'keynote' presentation, a series of individual panel sessions covering the above areas, with midway presentations by the panel chairpersons, followed by a final summarizing/integrating session by the individual panels, and a closing plenary session summarizing the results of the workshop
Taxation and Education: Using Educational Research to Inform Coherent Policy for the Public Good
In 2006, following a 30-year trend among the US states to remove the property tax from the revenue for public schools, the South Carolina General Assembly enacted Act 388 which replaced the property tax with a one-cent sales tax. The law decreased the budget capacity of school districts thus impacting educational equity and adequacy. This paper describes key policy makers’ and stakeholders’ interpretations of the pressure for property tax relief and highlight the importance of policy coherence in education finance, taxation, and accountability
Tension and Energy: Components of Arousal and their Effect on Intention to Give
In the current study we explore a multidimensional conceptualization of arousal to better understand the effect of donation appeals incorporating negative messages on intention to give. More specifically, an experiment is conducted to determine whether varying the level of message negativity has an impact on donor intentions to give where the mechanism by which intentions increase is examined. Using structural equation modeling, the relationship between message negativity, two dimensions of arousal (tension and energy) and intention to donate is estimated. We collected data using the background of an on-campus fund raising program for abused Afghani women held at a mid-size, southern university. The university’s freshman reading program using the book “Three Cups of Tea” generated a student fund raising initiative to support an educational initiative in Afghanistan. We developed a simulated donation message to induce activation/arousal and then measured arousal and intention to give. Two descriptions of the life of women in Afghanistan were developed as the stimuli messages for the experiment and presented to the subjects under the heading “EDUCATION FOR AFGHAN WOMEN.” The scenarios were developed from the descriptions in “Three Cups of Tea” to portray a negative and arousal-producing situation. Scenario Two was designed to produce a higher level of arousal with description of assaults with acid and self- immolation. The findings suggest message negativity positively influences donor intentions to give via the generation of tension. While increased energy levels were also observed among participants exposed to more negative messages, this did not translate into greater donation intentions. The implications of these findings and suggestions for future research are discusse
Information Systems and Health Care-II: Back to the Future with RFID: Lessons Learned - Some Old, Some New
Healthcare facilities face limited resources and expanding expenses. Emerging information technologies offer a means for healthcare to measure and control their resources and workflow processes, and ultimately improve patient care. The usefulness of one emerging information technology, Radio Frequency Identification (RFID), is examined in a proof of application study conducted at a Level-1 trauma unit. Results from the study suggest not only that RFID technology can assist in the measurement and ultimate control of workflow processes, but also that traditional and non-traditional IS practices are necessary for successful RFID implementation. Lessons learned about the idiosyncrasies of RFID implementation and the cleansing and analysis of RFID-generated data are reported
The prediction of multicomponent ion exchange equilibria with particular reference to the system involved in the recovery of uranium.
Thesis (Ph.D.)-University of Natal, Durban, 1976.The problem of predicting the general ion exchange equilibria
pertaining to systems of industrial significance is generated by
the multicomponent nature of such systems and the nonidealities which
may be present in both the solution and exchanger phases.
A general framework applicable to multicomponent systems
incorporating nonideal effects in both phases is presented. For the
solution phase a well established procedure for calculating activity
coefficients is adopted. Deviations from ideal behaviour in the
exchanger phase are modelled by the Wilson equation, which expresses
the excess Gibbs free energy of mixing of the resinates as a function
of composition. A Significant advantage is afforded by this equation
in that theoretically a multicomponent system may be predicted from
the binary interaction coefficients of this equation which are
determined experimentally, thereby reducing the otherwise extensive
experimental program.
These ideas are applied to systems of increasing complexity from
simple binary characterisation experiments to the prediction of a six
component system related to that encountered in the recovery of uranium
from sulphuric acid leach liquors. Experimentation for the systems involving the ions S04 2-, Cl- and NO-3 and a strong base anion exchanger have provided a severe test for
the procedure proposed. The agreement between the predicted and experimental
resin phase composition data for this ternary system is within ± 5%.
The addition of complexing agents complicates the procedure in that
it becomes physically impossible to decompose the system into the desirable
experimental binary systems. In this case higher order systems are
characterised. Introducing a mineral acid to the ternary system
discussed previously generates the HSO-4 ion which necessitates the
characterisation of other ternary systems before the quaternary system
may be predicted. The agreement between the predicted and experimental
resin phase composition for the quaternary system is shown to be within
± 10%. The work is easily extended to include the more complex systems
generated by the complexation of metal ions with the various ligands
present. .Provided the stoichiometry of the complex species in the
exchanger phase is well defined the complexes present no difficulties
in the characterisation procedures.
Experimental studies on the acidic uranyl sulphate quaternary
system provide the desired ion exchange equilibrium constants and the
interaction coefficients.
In order that the interaction coefficients for the ion pairs such as UO2 (SO4)2-2,
Cl- and U02 (SO4)2-2, NO-3 may be estimated it is necessary
to characterise two quinary systems. Nevertheless the characteristics
of lower order systems are employed to reduce the number of unknown
parameters.
Finally it is possible to predict the resin phase composition of
the six component system which results from chloride and nitrate species
being included in the acidic uranyl sulphate system. The quantitative
effects of all the components in the solution phase on the extent of
uranium loading are predicted.
Although the ferric ion is an important component in the industrial
situation this ion has been excluded from this work because at this
stage it is not possible to identify or measure the quantity of
the various ferric complexes present in the resin phase for a
particular solution condition
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