OPTIC: Orbiting Plutonian Topographic Image Craft Proposal for an Unmanned Mission to Pluto

The proposal for an unmanned probe to Pluto is presented and described. The Orbiting Plutonian Topographic Image Craft's (OPTIC's) trip will take twenty years and after its arrival, will begin its data collection which includes image and radar mapping, surface spectral analysis, and magnetospheric studies. This probe's design was developed based on the request for proposal of an unmanned probe to Pluto requirements. The distinct problems which an orbiter causes for each subsystem of the craft are discussed. The final design revolved around two important factors: (1) the ability to collect and return the maximum quantity of information on the Plutonian system; and (2) the weight limitations which the choice of an orbiting craft implied. The velocity requirements of this type of mission severely limited the weight available for mission execution-owing to the large portion of overall weight required as fuel to fly the craft with present technology. The topics covered include: (1) scientific instrumentation; (2) mission management; (3) power and propulsion; (4) attitude and articulation control; (5) structural subsystems; and (6) command, control, and communication

Constraining Primordial Non-Gaussianity With the Abundance of High Redshift Clusters

We show how observations of the evolution of the galaxy cluster number abundance can be used to constrain primordial non-Gaussianity in the universe. We carry out a maximum likelihood analysis incorporating a number of current datasets and accounting for a wide range of sources of systematic error. Under the assumption of Gaussianity, the current data prefer a universe with matter density $\Omega_m\simeq 0.3$ and are inconsistent with $\Omega_m=1$ at the $2\sigma$ level. If we assume $\Omega_m=1$, the predicted degree of cluster evolution is consistent with the data for non-Gaussian models where the primordial fluctuations have at least two times as many peaks of height $3\sigma$ or more as a Gaussian distribution does. These results are robust to almost all sources of systematic error considered: in particular, the $\Omega_m=1$ Gaussian case can only be reconciled with the data if a number of systematic effects conspire to modify the analysis in the right direction. Given an independent measurement of $\Omega_m$, the techniques described here represent a powerful tool with which to constrain non-Gaussianity in the primordial universe, independent of specific details of the non-Gaussian physics. We discuss the prospects and strategies for improving the constraints with future observations.Comment: Minor revisions to match published ApJ version, 14 pages emulateap

Changing Clinicians' Behaviors in an Academic Medical Center: Does Institutional Commitment to Total Quality Management Matter?

The purpose of this project was to determine whether changing clinicians' behaviors to reduce costs in a large academic medical center is facilitated by the prior existence of a total quality management program. Ten teams, made up primarily of clinicians, were charged with devising strategies for altering specific clinical behaviors to reduce costs without detriment to quality of care. Half the teams followed the center's total quality management approach. Team success was assessed by how well three key tasks were completed: problem definition, design of plan of action, and plan implementation. Two teams achieved outright success es, three had outright failures, and five were in between. Adherence to a total quality management approach was not found to be associated with team suc cess. A much better predictor of success was the level of involvement and support by clinicians and managers; because that factor is largely controlled by institution al incentives, those incentives may need to be realigned before the effectiveness of a total quality management approach can be properly evaluated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67013/2/10.1177_0885713x9701200102.pd

Atrial fibrillation in hemodialysis patients: clinical features and associations with anticoagulant therapy

Using data from the international Dialysis Outcomes and Practice Patterns Study (DOPPS), we determined incidence, prevalence, and outcomes among hemodialysis patients with atrial fibrillation. Cox proportional hazards models, to identify associations with newly diagnosed atrial fibrillation and clinical outcomes, were stratified by country and study phase and adjusted for descriptive characteristics and comorbidities. Of 17,513 randomly sampled patients, 2188 had preexisting atrial fibrillation, with wide variation in prevalence across countries. Advanced age, non-black race, higher facility mean dialysate calcium, prosthetic heart valves, and valvular heart disease were associated with higher risk of new atrial fibrillation. Atrial fibrillation at study enrollment was positively associated with all-cause mortality and stroke. The CHADS2 score identified approximately equal-size groups of hemodialysis patients with atrial fibrillation with low (less than 2) and higher risk (more than 4) for subsequent strokes on a per 100 patient-year basis. Among patients with atrial fibrillation, warfarin use was associated with a significantly higher stroke risk, particularly in those over 75 years of age. Our study shows that atrial fibrillation is common and associated with elevated risk of adverse clinical outcomes, and this risk is even higher among elderly patients prescribed warfarin. The effectiveness and safety of warfarin in hemodialysis patients require additional investigation

Ozone loss derived from balloon-borne tracer measurements and the SLIMCAT CTM

Balloon-borne measurements of CFC-11 (on flights of the DIRAC in situ gas chromatograph and the DESCARTES grab sampler), ClO and O3 were made during the 1999/2000 winter as part of the SOLVE-THESEO 2000 campaign. Here we present the CFC-11 data from nine flights and compare them first with data from other instruments which flew during the campaign and then with the vertical distributions calculated by the SLIMCAT 3-D CTM. We calculate ozone loss inside the Arctic vortex between late January and early March using the relation between CFC-11 and O3 measured on the flights, the peak ozone loss (1200 ppbv) occurs in the 440–470 K region in early March in reasonable agreement with other published empirical estimates. There is also a good agreement between ozone losses derived from three independent balloon tracer data sets used here. The magnitude and vertical distribution of the loss derived from the measurements is in good agreement with the loss calculated from SLIMCAT over Kiruna for the same days

Mephedrone (4-methylmethcathinone) and intracranial self-stimulation in C57BL/6J mice: Comparison to cocaine

The recreational use of cathinone-derived synthetic stimulants, also known as "bath salts", has increased during the last five years. A commonly abused drug in this class is mephedrone (4-methylmethcathinone or "meow-meow"), which alters mood and produces euphoria in humans. Intracranial self-stimulation (ICSS) measures the behavioral effects of neuroactive compounds on brain reward circuitry. We used ICSS to investigate the ability of mephedrone and cocaine to alter responding for electrical stimulation of the medial forebrain bundle in C57BL/6J mice. Adult male C57BL/6J mice (n=6) implanted with unipolar stimulating electrodes at the level of the lateral hypothalamus responded for varying frequencies of brain stimulation reward (BSR). The frequency that supported half maximal responding (EF50), the BSR threshold (θ(0)), and the maximum response rate were determined before and after intraperitoneal administration of saline, mephedrone (1.0, 3.0, or 10.0 mg/kg), or cocaine (1.0, 3.0, or 10.0 mg/kg). Mephedrone dose-dependently decreased EF50 (max. effect=72.3% of baseline), θ(0) (max. effect=59.6% of baseline), and the maximum response rate (max. effect=67.0% of baseline) beginning 15 min after administration. Beginning immediately after administration, cocaine dose-dependently lowered EF50 (max. effect=66.4% of baseline) and θ(0) (max. effect=60.1% of baseline) but did not affect maximum response rate. These results suggest that mephedrone, like cocaine, potentiates BSR, which may indicate its potential for abuse. Given the public health concern of stimulant abuse, future studies will be necessary to determine the cellular and behavioral effects of acute and chronic mephedrone use

Economic Valuation of Grazing Management Practices: Discrete Choice Modeling in Pastoral Systems of Kenya

This study estimates the economic contribution of grazing management practices in pastoral systems by specifically undertaking an economic analysis of pastoralists’ preferences for grazing management practices and the economic value pastoralists place on them. The study applied the discrete choice experiment technique using a D-optimal design, a multi-attribute preference elicitation method to evaluate the economic value of grazing management options practiced in pastoral areas of Kenya. The results show that pastoral communities derive positive utility in connected systems that enable reciprocal access to resources in both wet and dry seasons. Pastoralism adapts to spatial–temporal variability of pasture and water through herd mobility; hence the positive utility derived from practices that contribute to the availability of adequate water and pasture across the seasons. These findings provide empirical evidence on the social and economic net benefits of rangeland management practices that should be enhanced to promote sustainable management of rangeland resources

The Far-Infrared Spectral Energy Distributions of X-ray-selected Active Galaxies

[Abridged] We present ISO far-infrared (IR) observations of 21 hard X-ray selected AGN from the HEAO-1 A2 sample. We compare the far-IR to X-ray spectral energy distributions (SEDs) of this sample with various radio and optically selected AGN samples. The hard-X-ray selected sample shows a wider range of optical/UV shapes extending to redder near-IR colors. The bluer objects are Seyfert 1s, while the redder AGN are mostly intermediate or type 2 Seyferts. This is consistent with a modified unification model in which the amount of obscuring material increases with viewing angle and may be clumpy. Such a scenario, already suggested by differing optical/near-IR spectroscopic and X-ray AGN classifications, allows for different amounts of obscuration of the continuum emission in different wavebands and of the broad emission line region which results in a mixture of behaviors for AGN with similar optical emission line classifications. The resulting limits on the column density of obscuring material through which we are viewing the redder AGN are 100 times lower than for the standard optically thick torus models. The resulting decrease in optical depth of the obscuring material allows the AGN to heat more dust at larger radial distances. We show that an AGN-heated, flared, dusty disk with mass 10^9 solar and size of few hundred pc is able to generate optical-far-IR SEDs which reproduce the wide range of SEDs present in our sample with no need for an additional starburst component to generate the long-wavelength, cooler part of the IR continuum.Comment: 40 pages, 14 figures, accepted for publication in Astrophysical Journal, V. 590, June 10, 200

Intracranial self-stimulation in FAST and SLOW mice: effects of alcohol and cocaine

Sensitivity to the stimulant and rewarding effects of alcohol may be genetically-correlated traits that predispose individuals to developing an alcohol use disorder

Levetiracetam results in increased and decreased alcohol drinking with different access procedures in C57BL/6J mice

The antiepileptic, levetiracetam (LEV), has been investigated for the treatment of alcohol abuse. However, little is known about how LEV alters the behavioral effects of alcohol in laboratory animals. The acute effects of LEV on alcohol drinking by male C57BL/6J mice were investigated using two different drinking procedures, limited access (drinking-in-the-dark, or DID) and intermittent access (IA) drinking. In the first experiment (DID), mice had access to a single bottle containing alcohol or sucrose for four hours every-other day. In the second experiment (IA), mice had intermittent access to two bottles, one containing alcohol or sucrose and one containing water, for 24 h on Mon/Wed/Fri. In both experiments, mice were administered LEV (0.3 – 100 mg/kg i.p.) or vehicle 30 min before access to the drinking solutions. In the DID mice, LEV increased alcohol intake from 4.3 to 5.4 g/kg, while in the IA mice LEV decreased alcohol intake from 4.8 to 3.0 g/kg in the first 4 h of access and decreased 24 h alcohol intake from 20 g/kg to approximately 15 g/kg. These effects appear specific to alcohol, as LEV did not affect sucrose intake in either experiment. LEV appears to differentially affect drinking in animal models of moderate and heavier alcohol consumption