3,907 research outputs found
Changing attitudes to 'the change'
Copyright © 2004 Royal Australian College of General PractitionersBACKGROUND In order to practise efficiently, experienced doctors use heuristics (decision making shortcuts). In most cases decision making shortcuts improve the service we offer, allowing us to make appropriate decisions more quickly. However, occasionally shortcuts can mislead. It is important to reflect on the shortcuts we use so as to reduce the risk of mistakes. OBJECTIVE This article examines the potential pitfalls of decision making shortcuts using hormone therapy (HT) in menopause as an example. DISCUSSION Recent randomised controlled trials have changed the thinking on the risk-benefit ratio for HT. The previously assumed long term health benefits of HT for women during and beyond menopause resulted from shortcuts in decision making including ‘association means causation’ (observational data), ‘experts know best’ (the experience of gynaecologists seeing women with severe menopausal symptoms is applied to all women) and ‘a biological theory to explain a phenomenon makes it likely to be true’ (oestrogen has a positive effect on lipid profiles and so was assumed to be cardioprotective).Katrina Allen, Peter Mansfiel
Field condensations and Noncritical String for c>1
Quantum theory of 2d gravity for is examined as a non-critical string
theory by taking account of the loop-correction of open strings whose end
points are on the 2d world surface of the closed string. This loop-correction
leads to a conformal anomaly, and we obtain a modified target-space action
which implies a new phase of the non-critical closed-string. In this phase, the
dual field of the gauge field, which lives on the boundary, condenses and the
theory can be extended to without any instability.Comment: 17 pages, Latex, no figur
A simplicial gauge theory
We provide an action for gauge theories discretized on simplicial meshes,
inspired by finite element methods. The action is discretely gauge invariant
and we give a proof of consistency. A discrete Noether's theorem that can be
applied to our setting, is also proved.Comment: 24 pages. v2: New version includes a longer introduction and a
discrete Noether's theorem. v3: Section 4 on Noether's theorem has been
expanded with Proposition 8, section 2 has been expanded with a paragraph on
standard LGT. v4: Thorough revision with new introduction and more background
materia
3d absorption-spectra of Sr I through Sr IV
The extreme ultraviolet photoabsorption spectra of neutral to three-times-ionized strontium have been recorded in a comprehensive series of experiments with the dual laser-produced plasma technique. Striking differences were found in the spectra, which can be attributed to the transfer of oscillator strength from 3d→np to 3d→nf transitions at Sr2+ due to nf wave-function contraction. In Sr and Sr+, 3d→5p transitions dominate; in Sr2+, 3d→nf transitions are most intense, while in Sr3+ the 4p subshell opens and 3d→4p transitions are the strongest features. Partial cross sections for 3d→ɛf and 3d→ɛp photoionization were calculated and compared with experiment
Confidential Boosting with Random Linear Classifiers for Outsourced User-generated Data
User-generated data is crucial to predictive modeling in many applications.
With a web/mobile/wearable interface, a data owner can continuously record data
generated by distributed users and build various predictive models from the
data to improve their operations, services, and revenue. Due to the large size
and evolving nature of users data, data owners may rely on public cloud service
providers (Cloud) for storage and computation scalability. Exposing sensitive
user-generated data and advanced analytic models to Cloud raises privacy
concerns. We present a confidential learning framework, SecureBoost, for data
owners that want to learn predictive models from aggregated user-generated data
but offload the storage and computational burden to Cloud without having to
worry about protecting the sensitive data. SecureBoost allows users to submit
encrypted or randomly masked data to designated Cloud directly. Our framework
utilizes random linear classifiers (RLCs) as the base classifiers in the
boosting framework to dramatically simplify the design of the proposed
confidential boosting protocols, yet still preserve the model quality. A
Cryptographic Service Provider (CSP) is used to assist the Cloud's processing,
reducing the complexity of the protocol constructions. We present two
constructions of SecureBoost: HE+GC and SecSh+GC, using combinations of
homomorphic encryption, garbled circuits, and random masking to achieve both
security and efficiency. For a boosted model, Cloud learns only the RLCs and
the CSP learns only the weights of the RLCs. Finally, the data owner collects
the two parts to get the complete model. We conduct extensive experiments to
understand the quality of the RLC-based boosting and the cost distribution of
the constructions. Our results show that SecureBoost can efficiently learn
high-quality boosting models from protected user-generated data
Identifying patients with chronic widespread pain in primary care.
Chronic widespread pain (CWP) is common in the general population. It is unclear how people reporting this problem present in primary care; they may regularly consult for regional pains without being recognized as having a generalized condition. Our objectives were to determine the prevalence of people consulting in primary care for musculoskeletal conditions in different body regions on different occasions (recurrent regional pain consultation), the proportion with diagnosed generalized pain and survey-reported widespread pain, and if they have features characteristic of CWP. Phase 1 used electronic records from 12 general practices in North Staffordshire (Consultations in Primary Care Archive) from 2005 to 2009. Phase 2 used linked self-reported health and primary healthcare data from 8,286 people aged 50 plus in eight general practices (North Staffordshire Osteoarthritis Project) between 2002 and 2005. In Phase 1, 11% of registered patients fulfilled criteria for recurrent regional pain consultation. Three-quarters had no recorded CWP-related generalized pain condition (e.g. fibromyalgia). In Phase 2, 53% of recurrent regional pain consulters had survey-reported widespread pain and 88% had consulted for somatic symptoms. Self-reported general health was worse in recurrent regional pain consulters than in single-region consulters, and poorest in those who also reported persistent widespread pain. Recurrent regional pain consulters are a heterogeneous group of frequent consulters sharing features with CWP (e.g. somatic symptoms) but including those less severely affected. They lie on the spectrum of polysymptomatic distress characteristic of CWP and represent a group whose needs may be better met by earlier diagnosis of multi-site pain.This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Patan hospital experience in treating philadelphia chromosome/BCR-ABL1 positive chronic myeloid leukemia patients with gleevec (imatinib mesylate); the first generation specific tyrosine kinase inhibitor
<p>Abstract</p> <p>Background</p> <p>Chronic Myeloid Leukemia (CML) is caused by the abnormal fusion protein BCR-ABL1, a constitutively active tyrosine kinase and product of the Philadelphia chromosome. Gleevec (Imatinib mesylate) is a selective inhibitor of this kinase. Treatment with this agent is known to result in hematologic, cytogenetic, and molecular responses. Patan hospital (Patan, Nepal) is one of the Gleevec International Patient Assistance Program (GIPAP) centers for patients with CML.</p> <p>Methods</p> <p>A total of 106 Philadelphia positive CML patients were enrolled in our center between Feb 2003 and Jun 2008, and 103 of them were eligible for cytogenetic and/or hematologic response analyses.</p> <p>Results</p> <p>Out of 103 patients, 27% patients underwent cytogenetic analysis. Imatinib induced major cytogenetic responses in 89% and complete hematologic responses in almost 100% of the patients with confirmed CML. After a mean follow up of 27 months, an estimated 90% of the patients on imatinib remained in hematologic remission and more than 90% of the patients are still alive. About 30% of patients developed some form of manageable myelosuppression. A few patients developed non-hematologic toxic side effects such as edema and hepatotoxicity.</p> <p>Conclusions</p> <p>Our study demonstrates that imatinib is safe to use in a developing country. Furthermore, we demonstrate that imatinib is very effective and induced long lasting responses in a high proportion of patients with Ph chromosome/BCR-ABL1 positive CML. Imatinib is well tolerated by our patients. The lack of cytogenetic analysis in the majority of our patients hindered our ability to detect inadequate responses to imatinib and adjust therapy appropriately.</p
Surface energy and stability of stress-driven discommensurate surface structures
A method is presented to obtain {\it ab initio} upper and lower bounds to
surface energies of stress-driven discommensurate surface structures, possibly
non-periodic or exhibiting very large unit cells. The instability of the
stressed, commensurate parent of the discommensurate structure sets an upper
bound to its surface energy; a lower bound is defined by the surface energy of
an ideally commensurate but laterally strained hypothetical surface system. The
surface energies of the phases of the Si(111):Ga and Ge(111):Ga systems and the
energies of the discommensurations are determined within eV.Comment: 4 pages RevTeX. 2 Figures not included. Ask for a hard copy (through
regular mail) to [email protected]
Hamiltonian evolutions of twisted gons in \RP^n
In this paper we describe a well-chosen discrete moving frame and their
associated invariants along projective polygons in \RP^n, and we use them to
write explicit general expressions for invariant evolutions of projective
-gons. We then use a reduction process inspired by a discrete
Drinfeld-Sokolov reduction to obtain a natural Hamiltonian structure on the
space of projective invariants, and we establish a close relationship between
the projective -gon evolutions and the Hamiltonian evolutions on the
invariants of the flow. We prove that {any} Hamiltonian evolution is induced on
invariants by an evolution of -gons - what we call a projective realization
- and we give the direct connection. Finally, in the planar case we provide
completely integrable evolutions (the Boussinesq lattice related to the lattice
-algebra), their projective realizations and their Hamiltonian pencil. We
generalize both structures to -dimensions and we prove that they are
Poisson. We define explicitly the -dimensional generalization of the planar
evolution (the discretization of the -algebra) and prove that it is
completely integrable, providing also its projective realization
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