467 research outputs found
Toward Increased Utilization of Historical Hurricane Chronologies
The record of past tropical cyclones provides an important means to evaluate the hurricane hazard. Historical chronologies are a source of information about tropical cyclones prior to the modern era. Chenoweth (2006) describes an archive of 383 tropical cyclones occurring during the eighteenth and nineteenth centuries, largely before the official hurricane record. The present study demonstrates a novel way this archive can be used to articulate historical tropical cyclone activity across space. First, an event in the archive is assigned a series of latitude/longitude coordinates approximating the descriptive locations of the cyclone’s affect. Second, tropical cyclones from the modern record that approach these locations (modern analogs) are mapped. Third, a probable pathway and a realistic track of the archived event is created by averaging the modern analog tracks. As an example, the procedure is used to generate a map showing the tracks of the Atlantic tropical cyclones of 1766. Sensitivity of the methodology to changes in event location and event timing are considered. The study shows that historical hurricane chronologies when combined with a history of cyclone tracks can provide useful information about the older events that is not directly related to where the original information was gathered. When this information is available for all cyclones it should help climatologists better understand long-term variations in tropical cyclone activity
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Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016.
[This corrects the article DOI: 10.1186/s13054-016-1208-6.]
Extent of Social Inequalities in Disability in the Elderly: Results From a Population-based Study of British Men
Purpose
Little is known about social inequalities in disability in the elderly. We examined the extent and determinants of socioeconomic inequalities in disability and functional limitation in elderly men in Britain.
Methods
Disability was ascertained as problems with activities of daily living (ADLs) and instrumental ADL in a socioeconomically representative sample of 3981 men from 24 British towns who were between 63 to 82 years of age in 2003. We also examined functional limitation. Measures of socioeconomic position were social class, age at leaving full-time education, and car and house ownership.
Results
Men in lower social classes had greater risks of both ADL and instrumental ADL disability and functional limitation compared with higher social classes; odds ratios (95% CI) for social class V compared with I were 3.13 (1.64–5.97), 2.87 (1.49–5.51), and 2.65 (1.31–5.35), respectively. Behavioral risk factors (smoking, body mass index, physical activity) and particularly co-morbidity attenuated these differences; together, they reduced relative risks to 1.11 (0.49–2.51), 1.01 (0.45–2.25), and 1.05 (0.46–2.42). Age at leaving full-time education had no relation to functional limitations after taking social class into account. Men who were not house or car owners had greater odds of functional limitation and ADL disability compared with house or car owners, independent of behavioural risk factors, comorbidities and social class.
Conclusion
Strong socioeconomic inequalities in disability exist in the elderly, which were considerably explained by behavioral factors and comorbidity. Policy efforts are needed to reduce the social disparities in disability in the elderly
Defining the Cellular Environment in the Organ of Corti following Extensive Hair Cell Loss: A Basis for Future Sensory Cell Replacement in the Cochlea
Background: Following the loss of hair cells from the mammalian cochlea, the sensory epithelium repairs to close the lesions but no new hair cells arise and hearing impairment ensues. For any cell replacement strategy to be successful, the cellular environment of the injured tissue has to be able to nurture new hair cells. This study defines characteristics of the auditory sensory epithelium after hair cell loss. Methodology/Principal Findings: Studies were conducted in C57BL/6 and CBA/Ca mice. Treatment with an aminoglycoside-diuretic combination produced loss of all outer hair cells within 48 hours in both strains. The subsequent progressive tissue re-organisation was examined using immunohistochemistry and electron microscopy. There was no evidence of significant de-differentiation of the specialised columnar supporting cells. Kir4.1 was down regulated but KCC4, GLAST, microtubule bundles, connexin expression patterns and pathways of intercellular communication were retained. The columnar supporting cells became covered with non-specialised cells migrating from the outermost region of the organ of Corti. Eventually non-specialised, flat cells replaced the columnar epithelium. Flat epithelium developed in distributed patches interrupting regions of columnar epithelium formed of differentiated supporting cells. Formation of the flat epithelium was initiated within a few weeks post-treatment in C57BL/6 mice but not for several months in CBA/Ca’s, suggesting genetic background influences the rate of re-organisation
Assessing the validity of the global activity limitation indicator in fourteen European countries
Background: The Global Activity Limitation Indicator (GALI), the measure underlying the European indicator Healthy Life Years (HLY), is widely used to compare population health across countries. However, the comparability of the item has been questioned. This study aims to further validate the GALI in the adult European population. Methods: Data from the European Health Interview Survey (EHIS), covering 14 European countries and 152,787 individuals, were used to explore how the GALI was associated with other measures of disability and whether the GALI was consistent or reflected different disability situations in different countries. Results: When considering each country separately or all combined, we found that the GALI was significantly associated with measures of activities of daily living, instrumental activity of daily living, and functional limitations (P < 0.001 in all cases). Associations were largest for activity of daily living and lowest though still high for functional limitations. For each measure, the magnitude of the association was similar across most countries. Overall, however, the GALI differed significantly between countries in terms of how it reflected each of the three disability measures (P < 0.001 in all cases). We suspect cross-country differences in the results may be due to variations in: the implementation of the EHIS, the perception of functioning and limitations, and the understanding of the GALI question. Conclusion: The study both confirms the relevance of this indicator to measure general activity limitations in the European population and the need for caution when comparing the level of the GALI from one country to another
An ep collider with E/sub cm/=1 TeV in a VLHC booster tunnel
The low field option for the VLHC includes a 3 TeV proton booster with a circumference of 34 km. The authors are studying the option of an electron ring to fit in this tunnel which can produce ep collisions with a luminosity of 1 fb{sup {minus}1}/yr with a center of mass energy of 1 TeV. The machine would utilize superconducting rf and small low field magnets for the {approximately} 80 GeV electron beam. They describe the vacuum chamber/magnet system, rf power supply requirements, vacuum chamber cooling, interaction regions and installation of the facility in the tunnel, as well as provide preliminary estimates of beam stability and lifetimes
The history of degenerate (bipartite) extremal graph problems
This paper is a survey on Extremal Graph Theory, primarily focusing on the
case when one of the excluded graphs is bipartite. On one hand we give an
introduction to this field and also describe many important results, methods,
problems, and constructions.Comment: 97 pages, 11 figures, many problems. This is the preliminary version
of our survey presented in Erdos 100. In this version 2 only a citation was
complete
Generating inner ear organoids containing putative cochlear hair cells from human pluripotent stem cells
In view of the prevalence of sensorineural hearing defects in an ageing population, the development of protocols to generate cochlear hair cells and their associated sensory neurons as tools to further our understanding of inner ear development are highly desirable. We report herein a robust protocol for the generation of both vestibular and cochlear hair cells from human pluripotent stem cells which represents an advance over currently available methods that have been reported to generate vestibular hair cells only. Generating otic organoids from human pluripotent stem cells using a three-dimensional culture system, we show formation of both types of sensory hair cells bearing stereociliary bundles with active mechano-sensory ion channels. These cells share many morphological characteristics with their in vivo counterparts during embryonic development of the cochlear and vestibular organs and moreover demonstrate electrophysiological activity detected through single-cell patch clamping. Collectively these data represent an advance in our ability to generate cells of an otic lineage and will be useful for building models of the sensory regions of the cochlea and vestibule
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