4,673 research outputs found

    Intended and Unintended Consequences of For-Profit College Regulation: Examining the 90/10 Rule

    Get PDF
    The 90/10 rule dictates that no more than 90 percent of institutional revenue at a for-profit college or university (FPCU) can come from Title IV funds. The rule, originally an 85/15 ratio, was introduced in the 1992 amendments to the Higher Education Act and has been debated for 25 years. Proponents argue the rule raises institutional quality by eliminating low-quality institutions from the market, while opponents suggest that the rule creates perverse incentives for FPCUs to exclude high-need students and to raise prices. The author uses propensity score matching to estimate the effects of violating the 90/10 rule and the plausibility of these outcomes. The author provides minimal evidence that FPCUs raise tuition as a result of violating the rule, some evidence that Hispanic students may be excluded, some evidence of an increase in the number of certificates awarded, and strong evidence that violating schools are more likely to close

    Improving the worthiness of the Elder problem as a benchmark for buoyancy driven convection models

    Get PDF
    An important trapping mechanism associated with the geosequestration of CO~2~ is that of dissolution into the formation water. Although supercritical CO~2~ is significantly less dense than water, experimental data reported in the literature show that the density of an aqueous solution of CO~2~ could be slightly greater. Under normal situations, the transfer of gas to solution is largely controlled by the relatively slow process of molecular diffusion. However, the presence of variable densities can trigger off gravity instabilities leading to much larger-scale convection processes. Such processes can potentially enhance rates of dissolution by an order of magnitude. Consequently there is a need for future performance assessment models to incorporate buoyancy driven convection (BDC). A major issue associated with BDC models is that of grid convergence when benchmarking to the Elder problem. The Elder problem originates from a heat convection experiment whereby a rectangular Hele-Shaw cell was heated over the central half of its base. A quarter of the way through the experiment, Elder (1967) observed six plumes, with four narrow plumes in the center and two larger plumes at the edges. As the experiment progressed, only four plumes remained. The issue is that depending on the grid resolution used when seeking to model this problem, modelers have found that different schemes yield steady states with either one, two or three plumes. The aim of this paper is to clarify and circumvent the issue of multiple steady state solutions in the Elder problem using a pseudospectral method

    Construction of rugged, ultrastable optical assemblies with optical component alignment at the few microradian level

    Get PDF
    A method for constructing quasimonolithic, precision-aligned optical assemblies is presented. Hydroxide-catalysis bonding is used, adapted to allow optimization of component fine alignment prior to the bond setting. We demonstrate the technique by bonding a fused silica mirror substrate to a fused silica baseplate. In-plane component placement at the submicrometer level is achieved, resulting in angular control of a reflected laser beam at the sub-10-μrad level. Within the context of the LISA Pathfinder mission, the technique has been demonstrated as suitable for use in space-flight applications. It is expected that there will also be applications in a wide range of areas where accuracy, stability, and strength of optical assemblies are important

    Bimetallic Pt(II)-bipyridyl-diacetylide/Ln(III) tris-diketonate adducts based on a combination of coordinate bonding and hydrogen bonding between the metal fragments: syntheses, structures and photophysical properties

    Get PDF
    The luminescent Pt(II) complex [Pt(4,4'-Bu-t(2)-bipy){CC-(5-pyrimidinyl)}(2)] (1) was prepared by coupling of [Pt(4,4'-Bu-t(2)-bipy)Cl-2] with 5-ethynyl-pyrimidine, and contains two pyrimidinyl units pendant from a Pt(H) bipyridyl diacetylide core; it shows luminescence at 520 nm which is typical of Pt(II) luminophores of this type. Reaction with [Ln(hfac)(3)(H2O)(2)] (hfac = anion of hexafluoroacetylacetone) affords as crystalline solids the compounds [1 center dot {Ln(hfac)(3)(H2O)}{Ln(hfac)(3)(H2O)(2)}] (Ln = Nd, Gd, Er, Yb), in which the {Ln(hfac)(3)(H2O)} unit is coordinated to one pyrimidine ring via an N atom, whereas the {Ln(hfac)(3)(H2O)(2)} unit is associated with two N atoms, one from each pyrimidine ring of 1, via N center dot center dot center dot HOH hydrogen-bonding interactions involving the coordinated water ligands on the lanthanide centre. Solution spectroscopic studies show that the luminescence of 1 is partly quenched on addition of [Ln(hfac)(3)(H2O)(2)] (Ln = Er, Nd) by formation of Pt(II)/Ln(III) adducts in which Pt(II)-> Ln(III) photoinduced energy-transfer occurs to the low-lying f-f levels of the Ln(Ill) centre. Significant quenching occurs with both Er(Ill) and Nd(III) because both have several f-f states which match well the (MLCT)-M-3 emission energy of 1. Time-resolved luminescence studies show that Pt(II)-Er(III) energy-transfer (7.0 x 10(7) M-1) is around three times faster than Pt(II)-> Nd(III) energy-transfer (approximate to 2 x 10(7) M-1) over the same distance because the luminescence spectrum of l overlaps better with the absorption spectrum of Er(111) than with Nd(III). In contrast Yb(111) causes no significant quenching of 1 because it has only a single f-f excited level which is a poor energy match for the Pt(II)-based excited state

    Computed Tomography in Trauma Patients Accepted in Transfer:: Missed Injuries and Rationale for Repeat Imaging. Can we do Better?

    Get PDF
    Introduction. Computed tomography scans often are repeated ontrauma patient transfers, leading to increased radiation exposure,resource utilization, and costs. This study examined the incidenceof repeated computed tomography scans (RCT) in trauma patienttransfers before and after software upgrades, physician education,and encouragement to reduce RCT.Methods.xThe number of RCTs at an American College of SurgeonsCommittee on Trauma verified level 1 trauma center was measured.The trauma team was educated and encouraged to use the computedtomography scans received with transfer trauma patients as perstudy protocol. All available images were reviewed and reasons for aRCT when ordered were recorded and categorized. Impact of systemimprovements and education on subsequent RCT were evaluated.Results. A RCT was done on 47.2% (n = 76) of patients throughoutthe study period. Unacceptable image quality and possible misseddiagnoses were the most commonly reported reasons for a RCT. Preventablereasons for a RCT (attending refusal to read outside films,incompatible software, and physician preference) decreased from25.8 to 14.3% over the study periods.Conclusions. The volume of unnecessary RCT can be reduced primarilythrough software updates and physician education, therebydecreasing radiation exposure, patient cost, and inefficiencies in hospitalresource usage. Kans J Med 2019;12(1):7-10

    High-resolution measurements of surface topography with airborne laser altimetry and the global positioning system

    Get PDF
    Recently, an airborne lidar system that measures laser pulse time-of-flight and the distortion of the pulse waveform upon reflection from earth surface terrain features was developed and is now operational. This instrument is combined with Global Positioning System (GPS) receivers and a two-axis gyroscope for accurate recovery of aircraft position and pointing attitude. The laser altimeter system is mounted on a high-altitude aircraft platform and operated in a repetitively-pulsed mode for measurements of surface elevation profiles at nadir. The laser transmitter makes use of recently developed short-pulse diode-pumped solid-state laser technology in Q-switched Nd:YAG operating at its fundamental wavelength of 1064 nm. A reflector telescope and silicon avalanche photodiode are the basis of the optical receiver. A high-speed time-interval unit and a separate high-bandwidth waveform digitizer under microcomputer control are used to process the backscattered pulses for measurements of terrain. Other aspects of the lidar system are briefly discussed

    Increasing Onshore Oil Production: An Unexpected Explosion in Trauma Patients

    Get PDF
    Introduction. Few data currently exist which are focused on typeand severity of onshore oil extraction-related injuries. The purposeof this study was to evaluate injury patterns among onshore oil fieldoperations. Methods. A retrospective review was conducted of all traumapatients aged 18 and older with an onshore oil field-related injuryadmitted to an American College of Surgeons-verified level 1 traumacenter between January 1, 2003 and June 30, 2012. Data collectedincluded demographics, injury severity and details, hospital outcomes,and disposition. Results. A total of 66 patients met inclusion criteria. All patientswere male, of which the majority were Caucasian (81.8%, n = 54)with an average age of 36.5 ± 11.8 years, injury severity score of 9.4 ±8.9, and Glasgow Coma Scale score of 13.8 ± 3.4. Extremity injurieswere the most common (43.9%, n = 29), and most were the resultof being struck by an object (40.9%, n = 27). Approximately onethirdof patients (34.8%, n = 23) were admitted to the intensive careunit. Nine patients (13.6%) required mechanical ventilation while27 (40.9%) underwent operative treatment. The average hospitallength of stay was 5.8 ± 16.6 days, and most patients (78.8%, n = 52)were discharged home. Four patients suffered permanent disabilities,and there were two deaths. Conclusions. Increased domestic onshore oil production inevitablywill result in higher numbers of oil field-related traumas. By focusingon employees who are at the greatest risk for injuries and by targetingthe main causes of injuries, training programs can lead to a decreasein injury incidence. Kans J Med 2018;11(2):34-37

    Esophageal Fistula Complicating Thyroid Lobectomy

    Get PDF
    Thyroidectomy is associated with low morbidity and mortality. Esophageal perforation following thyroidectomy has been reported only three times previously, with subsequent fistulization occurring in two of these cases. The authors present the first such case report in the English-speaking literature

    Convergent Differential Regulation of Parvalbumin in the Brains of Vocal Learners

    Get PDF
    Spoken language and learned song are complex communication behaviors found in only a few species, including humans and three groups of distantly related birds – songbirds, parrots, and hummingbirds. Despite their large phylogenetic distances, these vocal learners show convergent behaviors and associated brain pathways for vocal communication. However, it is not clear whether this behavioral and anatomical convergence is associated with molecular convergence. Here we used oligo microarrays to screen for genes differentially regulated in brain nuclei necessary for producing learned vocalizations relative to adjacent brain areas that control other behaviors in avian vocal learners versus vocal non-learners. A top candidate gene in our screen was a calcium-binding protein, parvalbumin (PV). In situ hybridization verification revealed that PV was expressed significantly higher throughout the song motor pathway, including brainstem vocal motor neurons relative to the surrounding brain regions of all distantly related avian vocal learners. This differential expression was specific to PV and vocal learners, as it was not found in avian vocal non-learners nor for control genes in learners and non-learners. Similar to the vocal learning birds, higher PV up-regulation was found in the brainstem tongue motor neurons used for speech production in humans relative to a non-human primate, macaques. These results suggest repeated convergent evolution of differential PV up-regulation in the brains of vocal learners separated by more than 65–300 million years from a common ancestor and that the specialized behaviors of learned song and speech may require extra calcium buffering and signaling

    Partnerships for Health - Jeff HEALTH and the Rwanda Village Concept Project – A Model of Interdisciplinary Health Professions Student Global Education

    Get PDF
    A partnership between the Rwanda Village Concept Project (RVCP), a medical student program in Butare, and Jeff HEALTH (Helping East Africans Link to Health), a multidisciplinary student organization at ThomasJeffersonUniversity, has been working in two Rwandan villages for the past five years. Initially, The Rwanda Health and Healing Project consisted of two programs, a Genocide Survivors Village Transformation and creation of a GenocideMemorial Park. These programs lead to a comprehensive community health assessment, which: 1) documented the needs through key informant interviews and focus groups; 2) identified health resources currently available; and 3) reviewed needs in context of the social and political history of Rwanda. The partnership has grown and taken shape based on this assessment and students\u27 learning experiences. Medical, Nursing, Public Health and Occupational Therapy students have implemented programs in hygiene, malnutrition, HIV education, and malaria prevention. The Rwandan students monitor these programs monthly when the Jeff HEALTH students are stateside. The team partnered with the Mid-Atlantic Chapter of Engineers Without Borders in a latrine construction project. For each of the past 4 years, 3 Rwandan medical students have spent 2 months at Jefferson exploring community medicine as a discipline. A formal educational program and peer mentoring prepares Jeff HEALTH students for immersion into Rwandan projects. Based partially on the success of this model of collaboration and growing faculty and student interest,Jefferson has expanded its Global Health education initiatives to a 4-year longitudinal area of concentration in Population Health for medical students and a Certificate in Global Health in the MPH Program. Learning Objectives: Participants at the presentation will be able to: 1. Learn a method to develop a collaborative international health professional interdisciplinary student driven initiative 2. Identify strategies for sustaining programs through cooperative agreements between students at aUnited StatesAcademicHealthCenterand anEastAfricanMedicalSchool 3. Organize an interdisciplinary student global education program based on student experiences and interes
    corecore