1,479 research outputs found
The 2013 clinical course descriptors for multiple sclerosis: A clarification
The clinical courses of multiple sclerosis were defined in 1996 and refined in 2013 to provide a time-based assessment of the current status of the individual. These definitions have been successfully used by clinicians, clinical trialists, and regulatory authorities. Recent regulatory decisions produced variations and discrepancies in the use of the clinical course descriptions. We provide here a clarification of the concepts underlying these descriptions and restate the principles used in their development. Importantly, we highlight the critical importance of time framing the disease course modifiers activity and progression and clarify the difference between the terms worsening and progressing
Unified understanding of MS course is required for drug development
The treatment of multiple sclerosis (MS) has evolved remarkably over the past 25 years. This progress has been enabled by advances in research, drug development and active engagement of the scientific community with regulatory authorities. However, an inconsistent approach to MS disease courses could have a negative impact on the drug development process
Multifrequency Strategies for the Identification of Gamma-Ray Sources
More than half the sources in the Third EGRET (3EG) catalog have no firmly
established counterparts at other wavelengths and are unidentified. Some of
these unidentified sources have remained a mystery since the first surveys of
the gamma-ray sky with the COS-B satellite. The unidentified sources generally
have large error circles, and finding counterparts has often been a challenging
job. A multiwavelength approach, using X-ray, optical, and radio data, is often
needed to understand the nature of these sources. This chapter reviews the
technique of identification of EGRET sources using multiwavelength studies of
the gamma-ray fields.Comment: 35 pages, 22 figures. Chapter prepared for the book "Cosmic Gamma-ray
Sources", edited by K.S. Cheng and G.E. Romero, to be published by Kluwer
Academic Press, 2004. For complete article and higher resolution figures, go
to: http://www.astro.columbia.edu/~muk/mukherjee_multiwave.pd
X-ray emission from isolated neutron stars
X-ray emission is a common feature of all varieties of isolated neutron stars
(INS) and, thanks to the advent of sensitive instruments with good
spectroscopic, timing, and imaging capabilities, X-ray observations have become
an essential tool in the study of these objects. Non-thermal X-rays from young,
energetic radio pulsars have been detected since the beginning of X-ray
astronomy, and the long-sought thermal emission from cooling neutron star's
surfaces can now be studied in detail in many pulsars spanning different ages,
magnetic fields, and, possibly, surface compositions. In addition, other
different manifestations of INS have been discovered with X-ray observations.
These new classes of high-energy sources, comprising the nearby X-ray Dim
Isolated Neutron Stars, the Central Compact Objects in supernova remnants, the
Anomalous X-ray Pulsars, and the Soft Gamma-ray Repeaters, now add up to
several tens of confirmed members, plus many candidates, and allow us to study
a variety of phenomena unobservable in "standard'' radio pulsars.Comment: Chapter to be published in the book of proceedings of the 1st Sant
Cugat Forum on Astrophysics, "ICREA Workshop on the high-energy emission from
pulsars and their systems", held in April, 201
Juvenile idiopathic scoliosis treated with posterior arthrodesis and segmental pedicle screw instrumentation before the age of 9 years: a 5-year follow-up
<p>Abstract</p> <p>Study design</p> <p>Retrospective study.</p> <p>Objective</p> <p>To evaluate the radiological results of fusion with segmental pedicle screw fixation in juvenile idiopathic scoliosis with a minimum 5-year follow-up.</p> <p>Summary of background data</p> <p>Progression of spinal deformity after posterior instrumentation and fusion in immature patients has been reported by several authors. Segmental pedicle screw fixation has been shown to be effective in controlling both coronal and sagittal plane deformities. However, there is no long term study of fusion with segmental pedicle screw fixation in these group of patients.</p> <p>Methods</p> <p>Seven patients with juvenile idiopathic scoliosis treated by segmental pedicle screw fixation and fusion were analyzed. The average age of the patients was 7.4 years (range 5–9 years) at the time of the operation. All the patients were followed up 5 years or more (range 5–8 years) and were all Risser V at the most recent follow up. Three dimensional reconstruction of the radiographs was obtained and 3DStudio Max software was used for combining, evaluating and modifying the technical data derived from both 2d and 3d scan data.</p> <p>Results</p> <p>The preoperative thoracic curve of 56 ± 15° was corrected to 24 ± 17° (57% correction) at the latest follow-up. The lumbar curve of 43 ± 14° was corrected to 23 ± 6° (46% correction) at the latest follow-up. The preoperative thoracic kyphosis of 37 ± 13° and the lumbar lordosis of 33 ± 13° were changed to 27 ± 13° and 42 ± 21°, respectively at the latest follow-up. None of the patients showed coronal decompensation at the latest follow-up. Four patients had no evidence of crankshaft phenomenon. In two patients slight increase in Cobb angle at the instrumented segments with a significant increase in AVR suggesting crankshaft phenomenon was seen. One patient had a curve increase in both instrumented and non instrumented segments due to incorrect strategy.</p> <p>Conclusion</p> <p>In juvenile idiopathic curves of Risser 0 patients with open triradiate cartilages, routine combined anterior fusion to prevent crankshaft may not be warranted by posterior segmental pedicle screw instrumentation.</p
Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us
Supernova remnants (SNRs) arise from the interaction between the ejecta of a
supernova (SN) explosion and the surrounding circumstellar and interstellar
medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However,
to understand SNRs as a whole, large samples of SNRs must be assembled and
studied. Here, we describe the radio, optical, and X-ray techniques which have
been used to identify and characterize almost 300 Galactic SNRs and more than
1200 extragalactic SNRs. We then discuss which types of SNRs are being found
and which are not. We examine the degree to which the luminosity functions,
surface-brightness distributions and multi-wavelength comparisons of the
samples can be interpreted to determine the class properties of SNRs and
describe efforts to establish the type of SN explosion associated with a SNR.
We conclude that in order to better understand the class properties of SNRs, it
is more important to study (and obtain additional data on) the SNRs in galaxies
with extant samples at multiple wavelength bands than it is to obtain samples
of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by
Athem W. Alsabti and Paul Murdin. Final version available at
https://doi.org/10.1007/978-3-319-20794-0_90-
Transient pulsed radio emission from a magnetar
Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very
bright and highly variable X-ray emission that are believed to be powered by
ultra-strong magnetic fields of >1e14 G, according to the 'magnetar' model. The
radio pulsations that have been observed from more than 1,700 neutron stars
with weaker magnetic fields have never been detected from any of the dozen
known magnetars. The X-ray pulsar XTE J1810-197 was revealed (in 2003) as the
first AXP with transient emission when its luminosity increased 100-fold from
the quiescent level; a coincident radio source of unknown origin was detected
one year later. Here we show that XTE J1810-197 emits bright, narrow, highly
linearly polarized radio pulses, observed at every rotation, thereby
establishing that magnetars can be radio pulsars. There is no evidence of radio
emission before the 2003 X-ray outburst (unlike ordinary pulsars, which emit
radio pulses all the time), and the flux varies from day to day. The flux at
all radio frequencies is approximately equal -- and at >20 GHz XTE J1810-197 is
currently the brightest neutron star known. These observations link magnetars
to ordinary radio pulsars, rule out alternative accretion models for AXPs, and
provide a new window into the coronae of magnetars.Comment: accepted by Nature; some new data and significantly revised
discussio
San Francisco Hep B Free: A Grassroots Community Coalition to Prevent Hepatitis B and Liver Cancer
Chronic hepatitis B is the leading cause of liver cancer and the largest health disparity between Asian/Pacific Islanders (APIs) and the general US population. The Hep B Free model was launched to eliminate hepatitis B infection by increasing hepatitis B awareness, testing, vaccination, and treatment among APIs by building a broad, community-wide coalition. The San Francisco Hep B Free campaign is a diverse public/private collaboration unifying the API community, health care system, policy makers, businesses, and the general public in San Francisco, California. Mass-media and grassroots messaging raised citywide awareness of hepatitis B and promoted use of the existing health care system for hepatitis B screening and follow-up. Coalition partners reported semi-annually on activities, resources utilized, and system changes instituted. From 2007 to 2009, over 150 organizations contributed approximately $1,000,000 in resources to the San Francisco Hep B Free campaign. 40 educational events reached 1,100 healthcare providers, and 50% of primary care physicians pledged to screen APIs routinely for hepatitis B. Community events and fairs reached over 200,000 members of the general public. Of 3,315 API clients tested at stand-alone screening sites created by the campaign, 6.5% were found to be chronically infected and referred to follow-up care. A grassroots coalition that develops strong partnerships with diverse organizations can use existing resources to successfully increase public and healthcare provider awareness about hepatitis B among APIs, promote routine hepatitis B testing and vaccination as part of standard primary care, and ensure access to treatment for chronically infected individuals
The use of Goal Attainment Scaling in a community health promotion initiative with seniors
<p>Abstract</p> <p>Background</p> <p>Evaluating collaborative community health promotion initiatives presents unique challenges, including engaging community members and other stakeholders in the evaluation process, and measuring the attainment of goals at the collective community level. Goal Attainment Scaling (GAS) is a versatile, under-utilized evaluation tool adaptable to a wide range of situations. GAS actively involves all partners in the evaluation process and has many benefits when used in community health settings.</p> <p>Methods</p> <p>The purpose of this paper is to describe the use of GAS as a potential means of measuring progress and outcomes in community health promotion and community development projects. GAS methodology was used in a local community of seniors (n = 2500; mean age = 76 ± 8.06 SD; 77% female, 23% male) to a) collaboratively set health promotion and community partnership goals and b) objectively measure the degree of achievement, over- or under-achievement of the established health promotion goals. Goal attainment was measured in a variety of areas including operationalizing a health promotion centre in a local mall, developing a sustainable mechanism for recruiting and training volunteers to operate the health promotion centre, and developing and implementing community health education programs. Goal attainment was evaluated at 3 monthly intervals for one year, then re-evaluated again at year 2.</p> <p>Results</p> <p>GAS was found to be a feasible and responsive method of measuring community health promotion and community development progress. All project goals were achieved at one year or sooner. The overall GAS score for the total health promotion project increased from 16.02 at baseline (sum of scale scores = -30, average scale score = -2) to 54.53 at one year (sum of scale scores = +4, average scale score = +0.27) showing project goals were achieved above the expected level. With GAS methodology an amalgamated score of 50 represents the achievement of goals at the expected level.</p> <p>Conclusion</p> <p>GAS provides a "participatory", flexible evaluation approach that involves community members, research partners and other stakeholders in the evaluation process. GAS was found to be "user-friendly" and readily understandable by seniors and other community partners not familiar with program evaluation.</p
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