10,367 research outputs found
A comparison of methods for calculating general practice level socioeconomic deprivation
Background: A measure of the socioeconomic deprivation experienced by the registered patient population of a general practice is of interest because it can be used to explore the association between deprivation and a wide range of other variables measured at practice level. If patient level geographical data are available a population weighted mean area-based deprivation score can be calculated for each practice. In the absence of these data, an area-based deprivation score linked to the practice postcode can be used as an estimate of the socioeconomic deprivation of the practice population. This study explores the correlation between Index of Multiple Deprivation 2004 (IMD) scores linked to general practice postcodes (main surgery address alone and main surgery plus any branch surgeries), practice population weighted mean IMD scores, and practice level mortality (aged 1 to 75 years, all causes) for 38 practices in Rotherham UK.
Results: Population weighted deprivation scores correlated with practice postcode based scores (main surgery only, Pearson r = 0.74, 95% CI 0.54 to 0.85; main plus branch surgeries, r = 0.79, 95% CI 0.63 to 0.89). All cause mortality aged 1 to 75 correlated with deprivation (main surgery postcode based measure, r = 0.50, 95% CI 0.22 to 0.71; main plus branch surgery based score, r = 0.55, 95% CI 0.28 to 0.74); population weighted measure, r = 0.66, 95% CI 0.43 to 0.81).
Conclusion: Practice postcode linked IMD scores provide a valid proxy for a population weighted measure in the absence of patient level data. However, by using them, the strength of association between mortality and deprivation may be underestimated
Analysis of X-ray and EUV spectra of solar active regions
Data acquired by two flights of an array of six Bragg crystal spectrometers on an Aerobee rocket to obtain high spatial and spectral resolution observations of various coronal features at soft X-ray wavelengths (9-23A) were analyzed. The various aspects of the analysis of the X-ray data are described. These observations were coordinated with observations from the experiments on the Apollo Telescope Mount and the various data sets were related to one another. The Appendices contain the published results, abstracts of papers, computer code descriptions and preprints of papers, all produced as a result of this research project
Very High Energy Gamma Rays from Supernova Remnants and Constraints on the Galactic Interstellar Radiation Field
The large-scale Galactic interstellar radiation field (ISRF) is the result of
stellar emission and dust re-processing of starlight. Where the energy density
of the ISRF is high (e.g., the Galactic Centre), the dominant gamma-ray
emission in individual supernova remnants (SNRs), such as G0.9+0.1, may come
from inverse Compton (IC) scattering of the ISRF. Several models of the ISRF
exist. The most recent one, which has been calculated by us, predicts a
significantly higher ISRF than the well-used model of Mathis, Mezger, and
Panagia. However,comparison with data is limited to local observations. Based
on our current estimate of the ISRF we predict the gamma-ray emission in the
SNRs G0.9+0.1 and RXJ1713, and pair-production absorption features above 20 TeV
in the spectra of G0.9+0.1, J1713-381, and J1634-472. We discuss how GLAST,
along with current and future very high energy instruments, may be able to
provide upper bounds on the large-scale ISRF.Comment: To appear in the proceedings of the 1st GLAST Symposiu
Preparation, analysis and release of simulated interplanetary grains into low Earth orbit
Astronomical observations which reflect the optical and dynamical properties of interstellar and interplanetary grains are the primary means of identifying the shape, size, and the chemistry of extraterrestrial grain materials. Except for recent samplings of extraterrestrial particles in near-Earth orbit and in the stratosphere observations were the only method of deducing the properties of extraterrestrial particles. In order to elucidate the detailed characteristics of observed dust, the observations must be compared with theoretical studies, some of which are discussed in this volume, or compared with terrestrial laboratory experiments. The formation and optical characterization of simulated interstellar and interplanetary dust with particular emphasis on studying the properties on irregularly shaped particles were discussed. Efforts to develop the techniques to allow dust experiments to be carried out in low-Earth orbit were discussed, thus extending the conditions under which dust experiments may be performed
Comparison of phase-coherent and non-phase- coherent coded communications
Word-error probability versus signal-to-noise ratio evaluation for five communications system
Digital voltage-controlled oscillator
Digital voltage-controlled oscillator generates a variable frequency signal controlled linearly about a center frequency with high stability and is phase controlled by an applied voltage. Integration ahead of the digital circuitry provides linear operation with control voltage having appreciable noise components
Journalism and New Media: African-American Media Outlet and their Use of the Internet.
Just a few years ago, a student had to visit the library and search through the card catalog to do research; a mother had to stand in line to purchase movie tickets for her children; spouses of soldiers at war had to wait days for a letter to arrive from his/her significant other serving time overseas; and the list goes on. Today, all of this has changed - the advent of the Internet has revolutionized the lives of every individual across the globe in many ways. Students may now access the library card catalog online; a mother may purchase movie tickets in advance online; and spouses may communicate in real time via electronic mail (e-mail). The Internet makes all of this possible. This phenomenon has been the main source feeding globalization and, in essence, assisting in making the world smaller. We have the ability to communicate with anyone, at any time, anywhere on the planet, as well as make purchases without leaving the comfort of our homes. Obviously, this powerful tool, if used wisely, can be a huge asset for any business, especially the media. The news media thrives on immediacy and the percentage of people who are actually reading, viewing, and listening to their news stories. The quicker a story is published and distributed, the better, and the Internet provides unprecedented immediacy 1 2 and access to the world\u27 s population; therefore, some media outlets have taken a huge interest in the Internet and what it can offer. Others have not. Representatives from 14 African-American publications in Dallas and Houston, the most populated cities in Texas, were surveyed in September 2003. Additionally, 24 public relations professionals from two of the nation\u27s leading agencies, Hill and Knowlton and Fleishman-Hillard, were surveyed to gain insight on their perception of working with African-American media outlets and provide counsel on how to improve overall perception of these publications . . Getting African-American publications in the targeted areas to complete the . survey proved to be somewhat challenging. Only three provided feedback - two answered the survey and one explained why she wouldn\u27t answer it. Nonetheless, answers from the two who completed it, coupled with personal research yielded some results. Findings show that, as a whole, black newspapers and magazines in Dallas and Houston are not taking full advantage of the Internet. The majority of these publications have sites that are unavailable, have very little content and interactivity, and are not updated regularly. This is because of lack of funding. Most black publications do not have the wherewithal to maintain a web site. Though, the few that do host web sites to compliment their hub publication do a fair job of taking full advantage of all the benefits such as graphics, hyperlinks, and navigational tools. Content is news oriented with special pages for features like original poetry, religious perspectives, and community news highlighting successful blacks, from students to government officials. . There is a consensus among public relations professionals that the Internet is extremely beneficial for media outlets. They are appreciative of any outlet that makes 3 use of it for many reasons. Currently, they do not have a strong awareness of African American publications in their respective cities. This is due to the fact that most of these publications do not have an online presence and are not generated in database and Internet searches that public relations professionals frequently conduct. Having an easy to-use, content-rich web site gives public relations professionals the information they need in order to reach these publications should they be interested in pitching one of their client\u27 s stories. This could lead to increased visibility among businesses and future advertising dollars, yielding an increase in revenue. Results �rom each survey prove that web sites enhance a publication\u27s reputation, credibility, readership, and revenue. The survival of periodicals that target blacks may depend on the importance they place on becoming part of the digital environment by developing and maintaining a web site to enhance their hub publication
Dimensions of double-lumen tracheobronchial tubes
Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsThe diameter of the left main bronchus is the determining dimension when selecting the size of a left tracheobronchial (double-lumen) tube for lung separation. However, this information is not given by any manufacturer, either on the tube or in the package insert. This paper describes the lengths and diameters of the deflated bronchial cuff segment of left tracheobronchial tubes in common use. One hundred and seventy-one left tracheobronchial tubes ranging in size from 28 to 41 nominal French gauge from four manufacturers were measured. There was wide variation between tubes of the same nominal size from the same manufacturer. For tubes of the same size from the same manufacturer, the diameter of the segment with the deflated bronchial cuff varied by more than 1 mm in diameter in some instances.The diameter of the bronchial cuff segment did not consistently decrease as the nominal size decreased even for the same manufacturer. There was major overlap in diameters of the bronchial segments between Fr 41, Fr 39, and Fr 37 tubes from most manufacturers, so that some of the Fr 39 tubes have a bronchial cuff segment diameter as much as 0.5 mm larger than the Fr 41 tube. It is concluded that the current French gauge markings on left tracheobronchial tubes are of very limited value in determining the appropriate size to be selected for a patient. More accurate and consistent dimensions of tracheobronchial tubes are required to improve clinical selection.http://www.aaic.net.au/Article.asp?D=200136
Rapid soft X-ray fluctuations in solar flares observed with the X-ray polychromator
Three flares observed by the Soft X-Ray Polychromator on the Solar Maximum Mission were studied. Flare light curves from the Flat Crystal Spectrometer and Bent Crystal Spectrometer were examined for rapid signal variations. Each flare was characterized by an initial fast (less than 1 min) burst, observed by the Hard X-Ray Burst Spectrometer (HXRBS), followed by softer gradual X-ray emission lasting several minutes. From an autocorrelation function analysis, evidence was found for quasi-periodic fluctuations with rise and decay times of 10 s in the Ca XIX and Fe XXV light curves. These variations were of small amplitude (less than 20%), often coincided with hard X-ray emissions, and were prominent during the onset of the gradual phase after the initial hard X-ray burst. It is speculated that these fluctuations were caused by repeated energy injections in a coronal loop that had already been heated and filled with dense plasma associated with the initial hard X-ray burst
Observations of loops and prominences
We review recent observations by the Yohkoh-SXT (Soft X-ray Telescope) in collaboration with other spacecraft and ground-based observatories of coronal loops and prominences. These new results point to problems that SoHO will be able to address. With a unique combination of rapid-cadence digital imaging (greater than or equal to 32 s full-disk and greater than or equal to 2 s partial-frame images), high spatial resolution (greater than or equal to 2.5 arcsec pixels), high sensitivity (EM less than or equal to 10(exp 42) cm(exp -3)), a low-scatter mirror, and large dynamic range, SXT can observe a vast range of targets on the Sun. Over the first 21 months of Yohkoh operations SXT has taken over one million images of the corona and so is building up an invaluable long-term database on the large-scale corona and loop geometry. The most striking thing about the SXT images is the range of loop sizes and shapes. The active regions are a bright tangle of magnetic field lines, surrounded by a network of large-scale quiet-Sun loops stretching over distances in excess of 105 km. The cross-section of most loops seems to be constant. Loops displaying significant Gamma's are the exception, not the rule, implying the presence of widespread currents in the corona. All magnetic structures show changes. Time scales range from seconds to months. The question of how these structures are formed, become filled with hot plasma, and are maintained is still open. While we see the propagation of brightenings along the length of active-region loops and in X-ray jets with velocities of several hundred km/s, much higher velocities are seen in the quiet Sun. In XBP flares, for example, velocities of over 1000 km/s are common. Active-region loops seem to be in constant motion, moving slowly outward, carrying plasma with them. During flares, loops often produce localized brightenings at the base and later at the apex of the loop. Quiescent filaments and prominences have been observed regularly. Their coronal manifestation seems to be an extended arcade of loops overlying the filament. Reliable alignment of the ground-based data with the X-ray images make it possible to make a detailed intercomparison of the hot and cold plasma structures over extended periods. Hence we are able to follow the long-term evolution of these structures and see how they become destabilized and erupt
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