236 research outputs found
Development of a Toolkit to Evaluate Efficacy of the Respecting Choices© System of Advance Care Planning
In 1991 the United States Congress enacted the Patient Self-Determination Act which was an attempt by the government to improve completion rates of advance directives. Despite enactment of this law, completion rates of advance directives have remained relatively unchanged with only 18-36% of adult Americans having completed a document (United States Department of Health and Human Services, 2008). Nearly 90% of healthcare spending in the United States is on the management of chronic conditions (Centers for Disease Control and Prevention, 2015). As the baby boomer generation, which already has a high number of chronic conditions, ages our struggling healthcare system will be further strained. One important aspect of chronic disease management is advance care planning (Prystowsky, 2015). While various advance care planning programs exist, the Respecting Choices© program has been recommended by the Institute of Medicine (2015) as a viable framework to increase advance care planning activities and advance directive completion rates. A not-for-profit health care system located in West Michigan that is comprised of 12 hospitals, nearly 200 ambulatory care sites and network of more than 3,000 physicians, will soon begin implementing the Respecting Choices© advance care planning program. The proposed doctoral project includes development of a toolkit to evaluate the efficacy of the Respecting Choices© system of advance care planning at increasing advance directive completion rates and documentation of the advance directive in the medical record
Laboratory Simulations of the Titan Surface to Elucidate the Huygens Probe GCMS Observations
The Cassini/Huygens mission has vastly increased the information we have available to stndy Satnro's moon Titan. The complete mission has included an array of observational methods including remote sensing techniques, upper atmosphere in-situ saropling, and the descent of the Huygens probe directly through the atmosphere to the surface [1,2]. The instruments on the Huygens probe remain the ouly source of in-situ measurements at the surface of Titan, and work evaluating these measurements to create a pict.rre of the surface environment is ongoing. In particular, the Gas Chromatograph Mass Spectrometer (GCMS) experiment on Huygens found that although there were no heavy hydrocarbons detected in the lower atmosphere, a rich spectrum of mass peaks arose once the probe landed on the surface [3,4], However, to date it has not been possible to extract the identity and abundances of the many minor components of the spectra due to a lack of temperatnre- and instrumentappropriate data for the relevant species. We are performing laboratory stndies designed to elucidate the spectrum collected on Titan's surface, utilizing a cryogenic charober maintained at appropriate temperature and pressure conditions. The experiments will simulate the temperatnre rise experienced by the surface, which led to an enhanced signal of volatiles detected by the Huygens GCMS. The objective of this study is to exaroine the characteristics of various surface analogs as measured by the Huygens GCMS flight spare instrument, which is currently housed in our laboratory at NASA Goddard Space Flight Center (GSFC). This identification cannot be adequately accomplished through theoretical work alone since the thermodynamic properties of many species at these temperatnres (94 K, HASI measurement [5]) are not known
Calibration of the Neutral Mass Spectrometer for the Lunar Atmosphere and Dust Environment Explorer
Science objectives of the LADEE Mission are to (1) determine the composition, and time variability of the tenuous lunar atmosphere and (2) to characterize the dust environment and its variability. These studies will extend the in-situ characterization of the environment that were carried out decades ago with the Apollo missions and a variety of ground based studies. The focused LADEE measurements will enable a more complete understanding of dust and gas sources and sinks. Sources of gas include UV photo-stimulated desorption, sputtering by plasma and micrometeorites, as well as thermal release of species such as argon from the cold service or venting from the lunar interior. Sinks include recondensation on the surface and escape through a variety of mechanisms. The LADEE science payload consists of an Ultraviolet Spectrometer, a Neutral Mass Spectrometer, and a Dust Detector. The LADEE orbit will include multiple passes at or below 50 km altitude and will target repeated sampling at the sunrise terminator where exospheric density will be highest for some thermally released species. The science mission will be implemented in approximately three months to allow measurements to be made over a period of one or more lunations In addition to the science mission NASA will use this mission to demonstrate optical communication technology away from low Earth orbit
Modal Gating of Human CaV2.1 (P/Q-type) Calcium Channels: I. The Slow and the Fast Gating Modes and their Modulation by β Subunits
The single channel gating properties of human CaV2.1 (P/Q-type) calcium channels and their modulation by the auxiliary β1b, β2e, β3a, and β4a subunits were investigated with cell-attached patch-clamp recordings on HEK293 cells stably expressing human CaV2.1 channels. These calcium channels showed a complex modal gating, which is described in this and the following paper (Fellin, T., S. Luvisetto, M. Spagnolo, and D. Pietrobon. 2004. J. Gen. Physiol. 124:463–474). Here, we report the characterization of two modes of gating of human CaV2.1 channels, the slow mode and the fast mode. A channel in the two gating modes differs in mean closed times and latency to first opening (both longer in the slow mode), in voltage dependence of the open probability (larger depolarizations are necessary to open the channel in the slow mode), in kinetics of inactivation (slower in the slow mode), and voltage dependence of steady-state inactivation (occurring at less negative voltages in the slow mode). CaV2.1 channels containing any of the four β subtypes can gate in either the slow or the fast mode, with only minor differences in the rate constants of the transitions between closed and open states within each mode. In both modes, CaV2.1 channels display different rates of inactivation and different steady-state inactivation depending on the β subtype. The type of β subunit also modulates the relative occurrence of the slow and the fast gating mode of CaV2.1 channels; β3a promotes the fast mode, whereas β4a promotes the slow mode. The prevailing mode of gating of CaV2.1 channels lacking a β subunit is a gating mode in which the channel shows shorter mean open times, longer mean closed times, longer first latency, a much larger fraction of nulls, and activates at more positive voltages than in either the fast or slow mode
Calibration of the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite
The SAM suite of instruments on the "Curiosity" Rover of the Mars Science Laboratory (MSL) is designed to provide chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples. The mission of the MSL investigations is to advance beyond the successful search for aqueous transformation in surface environments at Mars toward a quantitative assessment of habitability and preservation through a series of chemical and geological measurements. The SAM suite was delivered in December 2010 (Figure 1) to the Jet Propulsion Laboratory for integration into the Curiosity Rover. We previously outlined the range of SAM solid and gas calibrations implemented or planned and here we discuss a specific set of calibration experiments to establish the response of the SAM Quadrupole Mass Spectrometer (QMS) to the four most abundant gases in the Martian atmosphere CO2, N2, Ar, and O2, A full SAM instrument description and calibration report is presently in preparation
The Genome Sequence DataBase: towards an integrated functional genomics resource
During 1998 the primary focus of the Genome Sequence DataBase (GSDB; http://www.ncgr.org/gsdb ) located at the National Center for Genome Resources (NCGR) has been to improve data quality, improve data collections, and provide new methods and tools to access and analyze data. Data quality has been improved by extensive curation of certain data fields necessary for maintaining data collections and for using certain tools. Data quality has also been increased by improvements to the suite of programs that import data from the International Nucleotide Sequence Database Collaboration (IC). The Sequence Tag Alignment and Consensus Knowledgebase (STACK), a database of human expressed gene sequences developed by the South African National Bioinformatics Institute (SANBI), became available within the last year, allowing public access to this valuable resource of expressed sequences. Data access was improved by the addition of the Sequence Viewer, a platform-independent graphical viewer for GSDB sequence data. This tool has also been integrated with other searching and data retrieval tools. A BLAST homology search service was also made available, allowing researchers to search all of the data, including the unique data, that are available from GSDB. These improvements are designed to make GSDB more accessible to users, extend the rich searching capability already present in GSDB, and to facilitate the transition to an integrated system containing many different types of biological data
Onboard Guidance for Reusable Rockets: Aerodynamic Descent and Powered Landing
This paper describes a novel general on-board guidance strategy which can be applied toboth the aerodynamically-controlled descent and the powered landing phase of reusable rockets.The proposed guidance method is based on sequential convex optimization applied to a Cartesianrepresentation of the equations of motion. The contributions are an exploitation of convexand non-convex contributions, which are processed separately to maximize the computationalefficiency of the approach, the inclusion of highly nonlinear terms represented by aerodynamicaccelerations, a complete reformulation of the problem based on the use of Euler angle rates ascontrol means, an improved transcription based on the use of a generalized hp pseudospectralmethod, and a dedicated formulation of the aerodynamic guidance problem for reusable rockets.The problem is solved for a 40 kN-class reusable rocket. Results show that the proposedtechnique is a very effective methodology able to satisfy all the constraints acting on the system,and can be potentially employed online to solve the entire descent phase of reusable rockets inreal-time
Prognostic Significance of Growth Kinetics in Newly Diagnosed Glioblastomas Revealed by Combining Serial Imaging with a Novel Biomathematical Model
Glioblastomas (GBMs) are the most aggressive primary brain tumors characterized by their rapid proliferation and diffuse infiltration of the brain tissue. Survival patterns in patients with GBM have been associated with a number of clinico-pathologic factors, including age and neurological status, yet a significant quantitative link to in vivo growth kinetics of each glioma has remained elusive. Exploiting a recently developed tool for quantifying glioma net proliferation and invasion rates in individual patients using routinely available magnetic resonance images (MRIs), we propose to link these patient-specific kinetic rates of biological aggressiveness to prognostic significance. Using our biologically-based mathematical model for glioma growth and invasion, examination of serial pre-treatment MRIs of 32 GBM patients allowed quantification of these rates for each patient’s tumor. Survival analyses revealed that even when controlling for standard clinical parameters (e.g., age, KPS) these model-defined parameters quantifying biologically aggressiveness (net proliferation and invasion rates) were significantly associated with prognosis. One hypothesis generated was that the ratio of the actual survival time after whatever therapies were employed to the duration of survival predicted (by the model) without any therapy would provide a “Therapeutic Response Index” (TRI) of the overall effectiveness of the therapies. The TRI may provided important information, not otherwise available, as to the effectiveness of the treatments in individual patients. To our knowledge, this is the first report indicating that dynamic insight from routinely obtained pre-treatment imaging may be quantitatively useful in characterizing survival of individual patients with GBM. Such a hybrid tool bridging mathematical modeling and clinical imaging may allow for statifying patients for clinical studies relative to their pretreatment biological aggressiveness
Galileo Probe Mass Spectrometer experiment
The Galileo Probe Mass Spectrometer (GPMS) is a Probe instrument designed to measure the chemical and isotopic composition including vertical variations of the constituents in the atmosphere of Jupiter. The measurement will be performed by in situ sampling of the ambient atmosphere in the pressure range from approximately 150 mbar to 20 bar. In addition batch sampling will be performed for noble gas composition measurement and isotopic ratio determination and for sensitivity enhancement of non-reactive trace gases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43775/1/11214_2004_Article_BF00216852.pd
The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe
Saturn's largest moon, Titan, remains an enigma, explored only by remote sensing from Earth, and by the Voyager and Cassini spacecraft. The most puzzling aspects include the origin of the molecular nitrogen and methane in its atmosphere, and the mechanism(s) by which methane is maintained in the face of rapid destruction by photolysis. The Huygens probe, launched from the Cassini spacecraft, has made the first direct observations of the satellite's surface and lower atmosphere. Here we report direct atmospheric measurements from the Gas Chromatograph Mass Spectrometer (GCMS), including altitude profiles of the constituents, isotopic ratios and trace species ( including organic compounds). The primary constituents were confirmed to be nitrogen and methane. Noble gases other than argon were not detected. The argon includes primordial Ar-36, and the radiogenic isotope Ar-40, providing an important constraint on the outgassing history of Titan. Trace organic species, including cyanogen and ethane, were found in surface measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62703/1/nature04122.pd
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