835 research outputs found
Variational Approach to Gaussian Approximate Coherent States: Quantum Mechanics and Minisuperspace Field Theory
This paper has a dual purpose. One aim is to study the evolution of coherent
states in ordinary quantum mechanics. This is done by means of a Hamiltonian
approach to the evolution of the parameters that define the state. The
stability of the solutions is studied. The second aim is to apply these
techniques to the study of the stability of minisuperspace solutions in field
theory. For a theory we show, both by means of perturbation
theory and rigorously by means of theorems of the K.A.M. type, that the
homogeneous minisuperspace sector is indeed stable for positive values of the
parameters that define the field theory.Comment: 26 pages, Plain TeX, no figure
Portable Catapult Launcher For Small Aircraft
An apparatus for launching an aircraft having a multiplicity of interconnected elongated tracks of rigid material forming a track system and wherein each elongated track has a predetermined elongated track cross-sectional design, a winch system connected to the track system wherein the winch system has a variable mechanical advantage, one or more elongated elastic members wherein one end of each of the one or more elongated elastic members is adjustably connected to the track system, and a carrier slidably mounted to the track system wherein the canier is connected to the winch system and to the other end of each of the one or more elongated elastic members
An Evaluation of Agreements Between Managed Care Organizations and Community-Based Mental Illness and Addiction Disorder Treatment and Prevention Providers
This Issue Brief, prepared for the Substance Abuse and Mental Health Services Administration (SAMHSA), examines contracts between managed care organizations (MCOs) and community-based providers of mental illness and addiction disorder treatment and prevention services (MI/AD providers). Building upon initial research published in 1997, this brief explores in depth one of the most hidden aspects of managed care: the relationship between the managed care organizations and health care providers
The Devolution of Managed Care Contractor Duties: Analysis and Implications for Public Policy in Managed Behavioral Health Care
This study, undertaken by the Center for Health Services Research and Policy at the George Washington University (GWU) School of Public Health and Health Services for the United States Department of Health and Human Services\u27 Substance Abuse and Mental Health Services Administration, analyzes the devolution of the legal duties assumed by managed care organizations (MCOs) in their contracts with group purchasers. Specifically, this study examines the delegation of MCO contractual duties related to member care and services to individual network providers by comparing the language used in master contracts between purchasers and MCOs with the language contained in agreements with network health care providers who serve members covered under the master contract
Rotary blood pump
A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein
RAC1 P29S regulates PD-L1 expression in melanoma.
Whole exome sequencing of cutaneous melanoma has led to the detection of P29 mutations in RAC1 in 5-9% of samples, but the role of RAC1 P29 mutations in melanoma biology remains unclear. Using reverse phase protein array analysis to examine the changes in protein/phospho-protein expression, we identified cyclin B1, PD-L1, Ets-1, and Syk as being selectively upregulated with RAC1 P29S expression and downregulated with RAC1 P29S depletion. Using the melanoma patient samples in TCGA, we found PD-L1 expression to be significantly increased in RAC1 P29S patients compared to RAC1 WT as well as other RAC1 mutants. The finding that PD-L1 is upregulated suggests that oncogenic RAC1 P29S may promote suppression of the antitumor immune response. This is a new insight into the biological function of RAC1 P29S mutations with potential clinical implications as PD-L1 is a candidate biomarker for increased benefit from treatment with anti-PD1 or anti-PD-L1 antibodies
FOXD3 Regulates VISTA Expression in Melanoma.
Immune checkpoint inhibitors have improved patient survival in melanoma, but the innate resistance of many patients necessitates the investigation of alternative immune targets. Many immune checkpoint proteins lack proper characterization, including V-domain Ig suppressor of T cell activation (VISTA). VISTA expression on immune cells can suppress T cell activity; however, few studies have investigated its expression and regulation in cancer cells. In this study, we observe that VISTA is expressed in melanoma patient samples and cell lines. Tumor cell-specific expression of VISTA promotes tumor onset in vivo, associated with increased intratumoral T regulatory cells, and enhanced PDL-1 expression on tumor-infiltrating macrophages. VISTA transcript levels are regulated by the stemness factor Forkhead box D3 (FOXD3). BRAF inhibition upregulates FOXD3 and reduces VISTA expression. Overall, this study demonstrates melanoma cell expression of VISTA and its regulation by FOXD3, contributing to the rationale for therapeutic strategies that combine targeted inhibitors with immune checkpoint blockade
Quality of life among adolescents with cerebral palsy: what does the literature tell us?
Developmental Medicine & Child Neurology, 49(3): pp. 225-231.This review describes trends in quality of life (QOL) and
health-related quality of life (HRQOL) among adolescents
with cerebral palsy (CP). Twenty original articles were
identified by a structured search of multiple databases and
grouped by design. Categories included descriptive crosssectional
studies (n=8), measurement validation studies
(n=9), and exploratory qualitative studies (n=3). Several
trends were apparent. First, individuals with CP are reported
to have decreased QOL and HRQOL compared with a
normative population in some but not all areas of well-being.
Second, functional status measures such as the Gross Motor
Function Classification System are reliable indicators of
variations in physical function, but do not correlate
consistently with psychosocial well-being. Third, although
adolescents with CP have different life issues than adults or
children, limited research on factors associated with QOL and
HRQOL has been described for this age range. We
recommend that clinicians and researchers interested in
assessing well-being among adolescents with CP include
participants from across the spectrum of motor impairment,
allow adolescents to self-report whenever possible, and assess
adolescents independently, rather than including them with
individuals from other age groups or clinical populations
Spacetime states and covariant quantum theory
In it's usual presentation, classical mechanics appears to give time a very
special role. But it is well known that mechanics can be formulated so as to
treat the time variable on the same footing as the other variables in the
extended configuration space. Such covariant formulations are natural for
relativistic gravitational systems, where general covariance conflicts with the
notion of a preferred physical-time variable. The standard presentation of
quantum mechanics, in turns, gives again time a very special role, raising well
known difficulties for quantum gravity. Is there a covariant form of
(canonical) quantum mechanics? We observe that the preferred role of time in
quantum theory is the consequence of an idealization: that measurements are
instantaneous. Canonical quantum theory can be given a covariant form by
dropping this idealization. States prepared by non-instantaneous measurements
are described by "spacetime smeared states". The theory can be formulated in
terms of these states, without making any reference to a special time variable.
The quantum dynamics is expressed in terms of the propagator, an object
covariantly defined on the extended configuration space.Comment: 20 pages, no figures. Revision: minor corrections and references
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