38,963 research outputs found
Charged analogue of Finch-Skea stars
We present solutions to the Einstein-Maxwell system of equations in
spherically symmetric gravitational fields for static interior spacetimes with
a specified form of the electric field intensity. The condition of pressure
isotropy yields three category of solutions. The first category is expressible
in terms of elementary functions and does not have an uncharged limit. The
second category is given in terms of Bessel functions of half-integer order.
These charged solutions satisfy a barotropic equation of state and contain
Finch-Skea uncharged stars. The third category is obtained in terms of modified
Bessel functions of half-integer order and does not have an uncharged limit.
The physical features of the charged analogue of the Finch-Skea stars are
studied in detail. In particular the condition of causality is satisfied and
the speed of sound does not exceed the speed of light. The physical analysis
indicates that this analogue is a realistic model for static charged
relativistic perfect fluid spheres.Comment: 17 pages, To appear in Int. J. Mod. Phys.
Urban heritage conservation and rapid urbanization : insights from Surat, India
Currently, heritage is challenged in the Indian city of Surat due to diverse pressures, including rapid urbanization, increasing housing demand, and socio‐cultural and climate changes. Where rapid demographic growth of urban areas is happening, heritage is disappearing at an alarming rate. Despite some efforts from the local government, urban cultural heritage is being neglected and historic buildings keep being replaced by ordinary concrete buildings at a worryingly rapid pace. Discussions of challenges and issues of Surat’s urban area is supported by a qualitative dataset, including in‐depth semi‐structured interviews and focus groups with local policy makers, planners, and heritage experts, triangulated by observation and a photo‐survey of two historic areas. Findings from this study reveal a myriad of challenges such as: inadequacy of urban conservation management policies and processes focused on heritage, absence of skills, training, and resources amongst decision makers and persistent conflict and competition between heritage conservation needs and developers’ interests. Furthermore, the values and significance of Surat’s tangible and intangible heritage is not fully recognized by its citizens and heritage stakeholders. A crucial opportunity exists for Surat to maximize the potential of heritage and reinforce urban identity for its present and future generations. Surat’s context is representative of general trends and conservation challenges and therefore recommendations developed in this study hold the potential to offer interesting insights to the wider planners and conservationists’ international community. This paper recommends thoughtful integration of sustainable heritage urban conservation into local urban development frameworks and the establishment of approaches that recognize the plurality of heritage values
Comparison of infraclavicular brachial plexus block with supraclavicular brachial plexus block in upper limb surgeries using peripheral nerve stimulator
Background: The supraclavicular approach to brachialplexus block (SCB) is indicated for operations of upper extremity distal to the shoulder; the infraclavicular block (ICB) is indicated for operations of distal arm, elbow, wrist, and hand. Objective of the study was to compare the infraclavicular brachial plexus block with supraclavicular brachial plexus block in upper limb surgeries using peripheral nerve stimulator.Methods: This prospective study was conducted among 78 patients, 39 in each group in infraclavicular block and supraclavicular block, posted for various upper limb surgeries on elective or emergency basis and compare both the groups for block performance time, onset of block, quality of block, duration of block, pulse rate, mean arterial pressure post-operative complication.Results: Duration of surgery, quality of block and success rate was almost similar in both the groups. The block performance time for infraclavicular block was more as compared to supraclavicular block. The duration of block is more in infraclavicular group as compared to supraclavicular group. The onset of sensory blockade, as well as motor blockade, was slightly earlier in supraclavicular group. Hemodynemic parameters were also almost similar in both groups. Our study encounters higher number of complications among supraclavicular group.Conclusions: Supraclavicular route require less time to perform the block and have a rapid onset of sensory and motor block, but the duration of sensory and motor blockage is less as compared to infraclavicular route. Both the groups have a similar quality of block and success rate, but the supraclavicular route is associated with various complications compared to infraclavicular route
Multiobjective Fuzzy Linear Programming Under Uncertain Resource Parameters
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
A pilot survey of junior doctors’ attitudes and awareness around medication review: time to change our educational approach?
© 2015, BMJ Publishing Group. All rights reserved.Objectives Our aim was to explore junior doctors attitudes and awareness around concepts related to medication review, in order to find ways to change the culture for reviewing, altering and stopping inappropriate or unnecessary medicines. Having already demonstrated the value of team working with senior doctors and pharmacists and the use of a medication review tool, we are now looking to engage first year clinicians and undergraduates in the process. Method An online survey about medication review was distributed among all 42 foundation year one (FY1) doctors at the Chelsea and Westminster Hospital NHS Foundation Trust in November 2014. Descriptive statistics were used for analysis. Results Twenty doctors completed the survey (48%). Of those, 17 believed that it was the pharmacists duty to review medicines; and 15 of 20 stated the general practitioner (GP). Sixteen of 20 stated that they would consult a senior doctor first before stopping medication. Eighteen of 20 considered the GP and consultant to be responsible for alterations, rather than themselves. Sixteen of 20 respondents were not aware of the availability of a medication review tool. Seventeen of 20 felt that more support from senior staff would help them become involved with medication review. Conclusions Junior doctors report feeling uncomfortable altering mediations without consulting a senior first. They appear to be building confidence with prescribing in their first year but not about the medication review process or questioning the drugs already prescribed. Consideration should be given to what we have termed a bottom-up educational approach to provide early experience of and change the culture around medication review, to include the education of undergraduate and foundation doctors and pharmacists
Weak-localization corrections to the conductivity of double quantum wells
The weak-localization contribution \delta\sigma(B) to the conductivity of a
tunnel-coupled double-layer electron system is evaluated and its behavior in
weak magnetic fields B perpendicular or parallel to the layers is examined. In
a perpendicular field B, \delta \sigma(B) increases and remains dependent on
tunneling as long as the magnetic field is smaller than \hbar/e D \tau_t, where
D is the in-plane diffusion coefficient and \tau_t the interlayer tunneling
time. If \tau_t is smaller than the inelastic scattering time, a parallel
magnetic field also leads to a considerable increase of the concuctivity
starting with a B**2 law and saturating at fields higher than \hbar/e Z (D
\tau_t)**(1/2), where Z is the interlayer distance. In the limit of coherent
tunneling, when \tau_t is comparable to elastic scattering time, \delta
\sigma(B) differs from that of a single-layer system due to ensuing
modifications of the diffusion coefficient. A possibility to probe the
weak-localization effect in double-layer systems by the dependence of the
conductivity on the gate-controlled level splitting is discussed.Comment: Text 18 pages in Latex/Revtex format, 4 Postscript figures. J. Phys.:
CM,in pres
Projecting prevalence by stage of care for prostate cancer and estimating future health service needs: protocol for a modelling study
Introduction Current strategies for the management of prostate cancer are inadequate in Australia. We will, in this study, estimate current service needs and project the future needs for prostate cancer patients in Australia. Methods and analysis First, we will project the future prevalence of prostate cancer for 2010-2018 using data for 1972-2008 from the New South Wales (NSW) Central Cancer Registry. These projections, based on modelled incidence and survival estimates, will be estimated using PIAMOD (Prevalence, Incidence, Analysis MODel) software. Then the total prevalence will be decomposed into five stages of care: initial care, continued monitoring, recurrence, last year of life and long-term survivor. Finally, data from the NSW Prostate Cancer Care and Outcomes Study, including data on patterns of treatment and associated quality of life, will be used to estimate the type and amount of services that will be needed by prostate cancer patients in each stage of care. In addition, Central Cancer Registry episode data will be used to estimate transition rates from localised or locally advanced prostate cancer to metastatic disease. Medicare and Pharmaceutical Benefits data, linked with Prostate Cancer Care and Outcomes Study data, will be used to complement the Cancer Registry episode data. The methods developed will be applied Australia-wide to obtain national estimates of the future prevalence of prostate cancer for different stages of clinical care. Ethics and dissemination This study was approved by the NSW Population and Health Services Research Ethics Committee. Results of the study will be disseminated widely to different interest groups and organisations through a report, conference presentations and peer-reviewed articles.This work is supported by the Prostate Cancer Foundation of Australia (grant number: PCFA – YI 0410). Both David Smith and Xue Qin Yu are supported by an Australian NHMRC Training Fellowship (Ref 1016598, 550002). Mark Clements is supported by an Australian NHMRC Career Development Award (Ref 471491)
Global Management Effectiveness Study: Integrated Social and Ecological Report for Non-node and Node Sites
The purpose of this study is to provide a critical assessment of the implementation, impact, and performance of Marine Managed Area (MMA) projects to serve as a basis for improved planning and implementation of new MMA projects worldwide. The specific objectives of the study are (1) to determine the socioeconomic, governance and ecological effects of MMAs; (2) to determine the critical factors influencing MMA effects, as well as the impact of the timing of those factors on the effects of the MMA; and (3) to provide tools for predicting MMA effects based on ecological, socioeconomic and governance variable
Investigating the intrinsic noise limit of Dayem bridge NanoSQUIDs
NanoSQUIDs made from Nb thin films have been produced with nanometre loop sizes down to 200 nm, using weak-link junctions with dimensions less than 60 nm. These composite (W/Nb) single layer thin film devices, patterned by FIB milling, show extremely good low-noise performance ∼170 nΦ0 at temperatures between 5 and 8.5 K and can operate in rather high magnetic fields (at least up to 1 T). The devices produced so far have a limited operating temperature range, typically only 1–2 K. We have the goal of achieving operation at 4.2 K, to be compatible with the best SQUID series array (SSA) preamplifier available. Using the SSA to readout the nanoSQUIDs provides us with a means of investigating the intrinsic noise of the former. In this paper we report improved white noise levels of these nanoSQUIDs, enabling potential detection of a single electronic spin flip in a 1-Hz bandwidth. At low frequencies the noise performance is already limited by SSA preamplifier noise
On the Scale-Invariant Distribution of the Diffusion Coefficient for Classical Particles Diffusing in Disordered Media.-
The scaling form of the whole distribution P(D) of the random diffusion
coefficient D(x) in a model of classically diffusing particles is investigated.
The renormalization group approach above the lower critical dimension d=0 is
applied to the distribution P(D) using the n-replica approach. In the annealed
approximation (n=1), the inverse gaussian distribution is found to be the
stable one under rescaling. This identification is made based on symmetry
arguments and subtle relations between this model and that of fluc- tuating
interfaces studied by Wallace and Zia. The renormalization-group flow for the
ratios between consecutive cumulants shows a regime of pure diffusion for small
disorder, in which P(D) goes to delta(D-), and a regime of strong disorder
where the cumulants grow infinitely large and the diffusion process is ill
defined. The boundary between these two regimes is associated with an unstable
fixed-point and a subdiffusive behavior: =Ct**(1-d/2). For the quenched
case (n goes to 0) we find that unphysical operators are generated raisng
doubts on the renormalizability of this model. Implications to other random
systems near their lower critical dimension are discussed.Comment: 21 pages, 1 fig. (not included) Use LaTex twic
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