7,388 research outputs found
The need for psychiatric treatment in the general population: the Camberwell Needs for Care Survey
Background, This paper presents the first results of a two-stage psychiatric population survey, which uses a new method of directly evaluating needs for specific psychiatric treatment and the extent to which they have been met.Method, The sample was drawn at random from the population of an area of inner south London with high levels of deprivation. Seven hundred and sixty subjects aged 18-65 completed the GHQ-28. All those scoring > 5 and half of the rest were invited to take part in the second stage, comprising measures of mental state (SCAN), social role performance (SRPS), life events and difficulties (LEDS) and a Treatment Inventory. This information was used to rate the community version of the Needs for Care Assessment (NFCAS-C).Results, In all, 408 subjects were interviewed in the second stage. The weighted 1 month prevalence of hierarchically ordered ICD-10 psychiatric disorders was 9.8 %, the 1 year prevalence 12.3 %. The equivalent prevalences for depressive episode were 3.1 % and 5.3 % respectively, while those for anxiety states were both 2.8 %. At interview nearly 10% of the population were identified as having a need for the treatment of a psychiatric condition. This rose to 10.4 % if the whole of the preceding year was assessed. Less than half of all potentially meetable needs were met. There was only partial overlap between diagnosis and an adjudged need for treatment.Conclusion. A majority of people with mental health problems do not have proper treatment; given more resources and greater public and medical awareness, most could be treated by family doctors
Routh reduction and the class of magnetic Lagrangian systems
In this paper, some new aspects related to Routh reduction of Lagrangian
systems with symmetry are discussed. The main result of this paper is the
introduction of a new concept of transformation that is applicable to systems
obtained after Routh reduction of Lagrangian systems with symmetry, so-called
magnetic Lagrangian systems. We use these transformations in order to show
that, under suitable conditions, the reduction with respect to a (full)
semi-direct product group is equivalent to the reduction with respect to an
Abelian normal subgroup. The results in this paper are closely related to the
more general theory of Routh reduction by stages.Comment: 23 page
Lie Groups and mechanics: an introduction
The aim of this paper is to present aspects of the use of Lie groups in
mechanics. We start with the motion of the rigid body for which the main
concepts are extracted. In a second part, we extend the theory for an arbitrary
Lie group and in a third section we apply these methods for the diffeomorphism
group of the circle with two particular examples: the Burger equation and the
Camassa-Holm equation
The study of the physics of cometary nuclei
A semiannual progress report describing the work completed during the period 1 September 1975 to 29 February 1976 on the physics of cometary nuclei was given. The following items were discussed: (1) a paper entitled ""A speculation about comets and the earth'', (2) a chapter entitled"" The physics of comets'' for ""Reviews of Astronomy and Astrophysics'', (3) continuing work on split comets, and (4) results dealing with a new application of nongravitational solar-radial forces as a measure of comet nucleus dimensions and activity
An Overview of Variational Integrators
The purpose of this paper is to survey some recent advances in variational
integrators for both finite dimensional mechanical systems as well as continuum
mechanics. These advances include the general development of discrete
mechanics, applications to dissipative systems, collisions, spacetime integration algorithms,
AVI’s (Asynchronous Variational Integrators), as well as reduction for
discrete mechanical systems. To keep the article within the set limits, we will only
treat each topic briefly and will not attempt to develop any particular topic in
any depth. We hope, nonetheless, that this paper serves as a useful guide to the
literature as well as to future directions and open problems in the subject
A millimeter-wave antireflection coating for cryogenic silicon lenses
We have developed and tested an antireflection (AR) coating method for
silicon lenses at cryogenic temperatures and millimeter wavelengths. Our
particular application is a measurement of the cosmic microwave background. The
coating consists of machined pieces of Cirlex glued to the silicon. The
measured reflection from an AR coated flat piece is less than 1.5% at the
design wavelength. The coating has been applied to flats and lenses and has
survived multiple thermal cycles from 300 to 4 K. We present the manufacturing
method, the material properties, the tests performed, and estimates of the loss
that can be achieved in practical lenses
Identification of Hemodynamically Optimal Coronary Stent Designs Based on Vessel Caliber
Coronary stent design influences local patterns of wall shear stress (WSS) that are associated with neointimal growth, restenosis, and the endothelialization of stent struts. The number of circumferentially repeating crowns NC for a given stent de- sign is often modified depending on the target vessel caliber, but the hemodynamic implications of altering NC have not previously been studied. In this investigation, we analyzed the relationship between vessel diameter and the hemodynamically optimal NC using a derivative-free optimization algorithm coupled with computational fluid dynamics. The algorithm computed the optimal vessel diameter, defined as minimizing the area of stent-induced low WSS, for various configurations (i.e., NC) of a generic slotted-tube design and designs that resemble commercially available stents. Stents were modeled in idealized coronary arteries with a vessel diameter that was allowed to vary between 2 and 5 mm. The results indicate that the optimal vessel diameter increases for stent configurations with greater NC, and the designs of current commercial stents incorporate a greater NC than hemodynamically optimal stent designs. This finding suggests that reducing the NC of current stents may improve the hemodynamic environment within stented arteries and reduce the likelihood of excessive neointimal growth and thrombus formation
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