9,347 research outputs found
Examining How Adverse Childhood Experiences and the Underlying Processes of Trait and State Impulsivity Influence Suicidal Behavior
ABSTRACT
Due to the effects of ACEs and impulsive behavior on mental and physical health, it is important to better understand the relationship between these two as well as how they both may influence choices, such as suicide. Numerous studies have identified impulsive behavior as a risk factor for suicide, however, recent research has identified several underlying independent processes that make up impulsivity. This study uses a broad assessment of trait and state impulsivity to gather a more discrete understanding of the underlying processes that contribute to impulsive behavior. The short version UPPS-P scale was used to measure negative urgency, lack of premeditation, lack of perseverance, sensation seeking, and positive urgency, and behavioral lab tasks were used to measure prepotent response inhibition, delay discounting, and distortions in elapsed time. Simple bivariate regressions revealed ACEs are a significant predictor of prepotent response inhibition, total S-UPPS-P scores, as well as the subscales of negative urgency, positive urgency, and sensation seeking. A hierarchical regression found total ACE scores, negative urgency, and distortions in elapsed time to be significant predictors of total suicidal behavior scores. Lastly, an ordinal logistic regression suggests a greater likelihood of going from suicidal ideation to planning, and from planning to attempting when ACEs, negative urgency, and lack of premeditation scores are greater. By identifying these specific dimensions of impulsivity as risk factors for suicidal behaviors, we can recognize individuals at greater risk of attempting, as well as target and mitigate the effects of these behaviors through interventions.
Keywords: Trait Impulsivity, State Impulsivity, ACEs, Suicidal Behavior
Comparison of two methods in estimating standard error of simulated moments estimators for generalized linear mixed models
We consider standard error of the method of simulated moment (MSM) estimator for generalized linear mixed models (GLMM). Parametric bootstrap (PB) has been used to estimate the covariance matrix, in which we use the estimates to generate the simulated moments. To avoid the bias introduced by estimating the parameters and to deal with the correlated observations, (Lu, 2012) proposed a multi-stage block nonparametric bootstrap to estimate the standard errors. In this research, we compare PB and nonparametric bootstrap methods (NPB) in estimating the standard errors of MSM estimators for GLMM. Simulation results show that when the group size is large, NPB and PB perform similarly; when group size is medium, NPB performs better than PB in estimating the mean. A data application is considered to illustrate the methods discussed in this paper, using productivity of plantation roses. The data application finds that the person caring for the roses is associated with the productivity of those beds. Furthermore, we did an initial study in applying random forests to predict the productivity of the rose beds
A View from the First Amendment Trenches: Washington State\u27s New Protections for Public Discourse and Democracy
In his latest book, Democracy, Expertise, and Academic Freedom: A First Amendment Jurisprudence for the Modern State, Dean Robert Post promotes the concept of “democratic legitimation” as the cornerstone of democratic decision making. Dean Post defines “democratic legitimation” as “all efforts” to influence “public opinion.” As Post explains, “[d]emocracy requires that government action be tethered to public opinion” because “public opinion can direct government action in an endless variety of directions.” As a result, First Amendment coverage should extend to all communications that form public opinion, he contends. Those who object to speech aimed at influencing public opinion have learned they can file a Strategic Lawsuit Against Public Participation (SLAPP). The purpose of the SLAPP suit is to impede efforts to influence public opinion by intimidating the speaker with expensive and lengthy litigation. Since the late 1980s, states have reacted to SLAPP lawsuits by enacting anti-SLAPP statutes. Washington State has had a statute in place since 1989 that protects speakers from litigation resulting from statements made to government officials. In 2010, the Washington legislature expanded those protections by enacting Revised Code of Washington 4.24.510, which more broadly protects speakers who comment on matters of public concern. This Article reviews Dean Post’s theory of democratic legitimation and then looks at statutes across the nation and in Washington that are aimed at protecting speakers from litigation that seeks to chill the First Amendment rights of citizens who comment on matters of public concern. The Article concludes that Washington’s new statute promotes Dean Post’s goal of democratic legitimation
How does the knowledge environment shape procurement practices for orthopaedic medical devices in Mexico?
BACKGROUND: In organisational theory there is an assumption that knowledge is used effectively in healthcare systems that perform well. Actors in healthcare systems focus on managing knowledge of clinical processes like, for example, clinical decision-making to improve patient care. We know little about connecting that knowledge to administrative processes like high-risk medical device procurement. We analysed knowledge-related factors that influence procurement and clinical procedures for orthopaedic medical devices in Mexico. METHODS: We based our qualitative study on 48 semi-structured interviews with various stakeholders in Mexico: orthopaedic specialists, government officials, and social security system managers or administrators. We took a knowledge-management related perspective (i) to analyse factors of managing knowledge of clinical procedures, (ii) to assess the role of this knowledge and in relation to procurement of orthopaedic medical devices, and (iii) to determine how to improve the situation. RESULTS: The results of this study are primarily relevant for Mexico but may also give impulsion to other health systems with highly standardized procurement practices. We found that knowledge of clinical procedures in orthopaedics is generated inconsistently and not always efficiently managed. Its support for procuring orthopaedic medical devices is insufficient. Identified deficiencies: leaders who lack guidance and direction and thus use knowledge poorly; failure to share knowledge; insufficiently defined formal structures and processes for collecting information and making it available to actors of health system; lack of strategies to benefit from synergies created by information and knowledge exchange. Many factors are related directly or indirectly to technological aspects, which are insufficiently developed. CONCLUSIONS: The content of this manuscript is novel as it analyses knowledge-related factors that influence procurement of orthopaedic medical devices in Mexico. Based on our results we recommend that the procurement mechanism should integrate knowledge from clinical procedures adequately in their decision-making. Without strong guidance, organisational changes, and support by technological solutions to improve the generation and management of knowledge, procurement processes for orthopaedic high-risk medical devices will remain sub-optimal
SI Engine Simulation Using Residual Gas and Neural Network Modeling to Virtually Estimate the Fuel Composition
Research in electronic controlled internal
combustion engines mainly focuses on improving performance
and lowering the emissions. Combustion performance depends
on the geometry of cylinders and on the design of all
mechanical parts, which are based on the laboratory
experimental research. Due to the limitations of the materials
used in the engine and the continuous high operating
temperature, engines function in either spark ignition or
charge ignition processes. Recent research on computer
controlled engines uses sensors and electronic actuators which
allows switching the engine operational mode between spark
ignition and charge ignition. Thus, this makes possible to mix
intake fuel compositions in order to give more choices to
consumers.
This study employs a neural network which is capable of
estimating fuel composition using the parameters of residual
gas. The simulation is based on a thermodynamic engine model
implemented in Matlab Simulink. The main advantages are the
capabilities of the model to 1) calculate the gas exchange as a
function of time in transient mode, and 2) to generate data for
the design control algorithms without the need of the engine
bed test environment to test various fuel compositions
Speckle visibility spectroscopy and variable granular fluidization
We introduce a dynamic light scattering technique capable of resolving motion
that changes systematically, and rapidly, with time. It is based on the
visibility of a speckle pattern for a given exposure duration. Applying this to
a vibrated layer of glass beads, we measure the granular temperature and its
variation with phase in the oscillation cycle. We observe several transitions
involving jammed states, where the grains are at rest during some portion of
the cycle. We also observe a two-step decay of the temperature on approach to
jamming.Comment: 4 pages, 4 figures, experimen
Gene therapy restores vision in rd1 mice after removal of a confounding mutation in Gpr179
The rd1 mouse with a mutation in the Pde6b gene was the first strain of mice identified with a retinal degeneration. However, AAV-mediated gene supplementation of rd1 mice only results in structural preservation of photoreceptors, and restoration of the photoreceptor-mediated a-wave, but not in restoration of the bipolar cell-mediated b-wave. Here we show that a mutation in Gpr179 prevents the full restoration of vision in rd1 mice. Backcrossing rd1 with C57BL6 mice reveals the complete lack of b-wave in a subset of mice, consistent with an autosomal recessive Mendelian inheritance pattern. We identify a mutation in the Gpr179 gene, which encodes for a G-protein coupled receptor localized to the dendrites of ON-bipolar cells. Gene replacement in rd1 mice that are devoid of the mutation in Gpr179 successfully restores the function of both photoreceptors and bipolar cells, which is maintained for up to 13 months. Our discovery may explain the failure of previous gene therapy attempts in rd1 mice, and we propose that Grp179 mutation status should be taken into account in future studies involving rd1 mice
Subdiffusive axial transport of granular materials in a long drum mixer
Granular mixtures rapidly segregate radially by size when tumbled in a
partially filled horizontal drum. The smaller component moves toward the axis
of rotation and forms a buried core, which then splits into axial bands. Models
have generally assumed that the axial segregation is opposed by diffusion.
Using narrow pulses of the smaller component as initial conditions, we have
characterized axial transport in the core. We find that the axial advance of
the segregated core is well described by a self-similar concentration profile
whose width scales as , with . Thus, the
process is subdiffusive rather than diffusive as previously assumed. We find
that is nearly independent of the grain type and drum rotation rate
within the smoothly streaming regime. We compare our results to two
one-dimensional PDE models which contain self-similarity and subdiffusion; a
linear fractional diffusion model and the nonlinear porous medium equation.Comment: 4 pages, 4 figures, 1 table. Submitted to Phys Rev Lett. For more
info, see http://www.physics.utoronto.ca/nonlinear
Measured Laboratory and In-Use Fuel Economy Observed over Targeted Drive Cycles for Comparable Hybrid and Conventional Package Delivery Vehicles
In-use and laboratory-derived fuel economies were analyzed for a medium-duty hybrid electric drivetrain with 'engine off at idle' capability and a conventional drivetrain in a typical commercial package delivery application. Vehicles studied included eleven 2010 Freightliner P100H hybrids in service at a United Parcel Service facility in Minneapolis during the first half of 2010. The hybrids were evaluated for 18 months against eleven 2010 Freightliner P100D diesels at the same facility. Both vehicle groups use the same 2009 Cummins ISB 200-HP engine. In-use fuel economy was evaluated using UPS's fueling and mileage records, periodic ECM image downloads, and J1939 CAN bus recordings during the periods of duty cycle study. Analysis of the in-use fuel economy showed 13%-29% hybrid advantage depending on measurement method, and a delivery route assignment analysis showed 13%-26% hybrid advantage on the less kinetically intense original diesel route assignments and 20%-33% hybrid advantage on the more kinetically intense original hybrid route assignments. Three standardized laboratory drive cycles were selected that encompassed the range of real-world in-use data. The hybrid vehicle demonstrated improvements in ton-mi./gal fuel economy of 39%, 45%, and 21% on the NYC Comp, HTUF Class 4, and CARB HHDDT test cycles, respectively
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