3,618 research outputs found
Kinematics of Magnetic Bright Features in the Solar Photosphere
Convective flows are known as the prime means of transporting magnetic fields
on the solar surface. Thus, small magnetic structures are good tracers of the
turbulent flows. We study the migration and dispersal of magnetic bright
features (MBFs) in intergranular areas observed at high spatial resolution with
Sunrise/IMaX. We describe the flux dispersal of individual MBFs as a diffusion
process whose parameters are computed for various areas in the quiet Sun and
the vicinity of active regions from seeing-free data. We find that magnetic
concentrations are best described as random walkers close to network areas
(diffusion index, gamma=1.0), travelers with constant speeds over a
supergranule (gamma=1.9-2.0), and decelerating movers in the vicinity of flux
emergence and/or within active regions (gamma=1.4-1.5). The three types of
regions host MBFs with mean diffusion coefficients of 130 km^2/s, 80-90 km^2/s,
and 25-70 km^2/s, respectively. The MBFs in these three types of regions are
found to display a distinct kinematic behavior at a confidence level in excess
of 95%.Comment: 8 pages, 4 figure
Morphological properties of slender Ca II H fibrils observed by SUNRISE II
We use seeing-free high spatial resolution Ca II H data obtained by the
SUNRISE observatory to determine properties of slender fibrils in the lower
solar chromosphere. In this work we use intensity images taken with the SUFI
instrument in the Ca II H line during the second scientific flight of the
SUNRISE observatory to identify and track elongated bright structures. After
the identification, we analyze theses structures in order to extract their
morphological properties. We identify 598 slender Ca II H fibrils (SCFs) with
an average width of around 180 km, a length between 500 km and 4000 km, an
average lifetime of ~400 s, and an average curvature of 0.002 arcsec^-1. The
maximum lifetime of the SCFs within our time series of 57 minutes is ~2000 s.
We discuss similarities and differences of the SCFs with other small-scale,
chromospheric structures such as spicules of type I and II, or Ca II K fibrils.Comment: Accepted for publication in The Astrophysical Journal Supplement
Serie
Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields
How and where are coronal loops rooted in the solar lower atmosphere? The
details of the magnetic environment and its evolution at the footpoints of
coronal loops are crucial to understanding the processes of mass and energy
supply to the solar corona. To address the above question, we use
high-resolution line-of-sight magnetic field data from the Imaging Magnetograph
eXperiment instrument on the SUNRISE balloon-borne observatory and coronal
observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics
Observatory of an emerging active region. We find that the coronal loops are
often rooted at the locations with minor small-scale but persistent
opposite-polarity magnetic elements very close to the larger dominant polarity.
These opposite-polarity small-scale elements continually interact with the
dominant polarity underlying the coronal loop through flux cancellation. At
these locations we detect small inverse Y-shaped jets in chromospheric Ca II H
images obtained from the SUNRISE Filter Imager during the flux cancellation.
Our results indicate that magnetic flux cancellation and reconnection at the
base of coronal loops due to mixed polarity fields might be a crucial feature
for the supply of mass and energy into the corona.Comment: Published in the Astrophysical Journal Supplement Serie
Multimorbidity Patterns in Elderly Primary Health Care Patients in a South Mediterranean European Region: A Cluster Analysis.
Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from Public Library of Science via the DOI in this record.OBJECTIVE: The purpose of this study was to identify clusters of diagnoses in elderly patients with multimorbidity, attended in primary care. DESIGN: Cross-sectional study. SETTING: 251 primary care centres in Catalonia, Spain. PARTICIPANTS: Individuals older than 64 years registered with participating practices. MAIN OUTCOME MEASURES: Multimorbidity, defined as the coexistence of 2 or more ICD-10 disease categories in the electronic health record. Using hierarchical cluster analysis, multimorbidity clusters were identified by sex and age group (65-79 and ≥80 years). RESULTS: 322,328 patients with multimorbidity were included in the analysis (mean age, 75.4 years [Standard deviation, SD: 7.4], 57.4% women; mean of 7.9 diagnoses [SD: 3.9]). For both men and women, the first cluster in both age groups included the same two diagnoses: Hypertensive diseases and Metabolic disorders. The second cluster contained three diagnoses of the musculoskeletal system in the 65- to 79-year-old group, and five diseases coincided in the ≥80 age group: varicose veins of the lower limbs, senile cataract, dorsalgia, functional intestinal disorders and shoulder lesions. The greatest overlap (54.5%) between the three most common diagnoses was observed in women aged 65-79 years. CONCLUSION: This cluster analysis of elderly primary care patients with multimorbidity, revealed a single cluster of circulatory-metabolic diseases that were the most prevalent in both age groups and sex, and a cluster of second-most prevalent diagnoses that included musculoskeletal diseases. Clusters unknown to date have been identified. The clusters identified should be considered when developing clinical guidance for this population.This study was supported by a grant from the Ministry of Science and Innovation through the Instituto Carlos III (ISCiii) in the 2012 call for Strategic Health Action proposals under the National Plan for Scientific Research, Development and Technological Innovation 2008–2011; by the European Union through the European Regional Development Fund (IP12/00427), as part of the Primary Care Prevention and Health Promotion Research Network (rediAPP), by ISCiii-RETICS (RD12/0005), by a 2011–2013 scholarship that aims to promote research in Primary Health Care by health professionals who have completed their specialty training, awarded by Institut Universitari d’Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), by a National Institute for Health Research Clinician Scientist Award (Jose M Valderas, NIHR/CS/010/024) and by a grant from the XIX call for research projects in the elderly population by Agrupació Mútua Foundation (Premio ámbito para las personas mayores, 2012). The funders had no role in the study design, collection, analysis and interpretation of data, writing of the manuscript or decision to submit for publication
On the Cauchy problem for a nonlinearly dispersive wave equation
We establish the local well-posedness for a new nonlinearly dispersive wave
equation and we show that the equation has solutions that exist for indefinite
times as well as solutions which blowup in finite times. Furthermore, we derive
an explosion criterion for the equation and we give a sharp estimate from below
for the existence time of solutions with smooth initial data.Comment: arxiv version is already officia
Burden of multimorbidity, socioeconomic status and use of health services across stages of life in urban areas: a cross-sectional study
This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.Background
The burden of chronic conditions and multimorbidity is a growing health problem in developed countries. The study aimed to determine the estimated prevalence and patterns of multimorbidity in urban areas of Catalonia, stratified by sex and adult age groups, and to assess whether socioeconomic status and use of primary health care services were associated with multimorbidity.
Methods
A cross-sectional study was conducted in Catalonia. Participants were adults (19+ years) living in urban areas, assigned to 251 primary care teams. Main outcome: multimorbidity (≥2 chronic conditions). Other variables: sex (male/female), age (19–24; 25–44; 45–64; 65–79; 80+ years), socioeconomic status (quintiles), number of health care visits during the study.
Results
We included 1,356,761 patients; mean age, 47.4 years (SD: 17.8), 51.0% women. Multimorbidity was present in 47.6% (95% CI 47.5-47.7) of the sample, increasing with age in both sexes but significantly higher in women (53.3%) than in men (41.7%). Prevalence of multimorbidity in each quintile of the deprivation index was higher in women than in men (except oldest group). In women, multimorbidity prevalence increased with quintile of the deprivation index. Overall, the median (interquartile range) number of primary care visits was 8 (4–14) in multimorbidity vs 1 (0–4) in non-multimorbidity patients. The most prevalent multimorbidity pattern beyond 45 years of age was uncomplicated hypertension and lipid disorder. Compared with the least deprived group, women in other quintiles of the deprivation index were more likely to have multimorbidity than men until 65 years of age. The odds of multimorbidity increased with number of visits in all strata.
Conclusions
When all chronic conditions were included in the analysis, almost 50% of the adult urban population had multimorbidity. The prevalence of multimorbidity differed by sex, age group and socioeconomic status. Multimorbidity patterns varied by life-stage and sex; however, circulatory-endocrine-metabolic patterns were the most prevalent multimorbidity pattern after 45 years of age. Women younger than 80 years had greater prevalence of multimorbidity than men, and women’s multimorbidity prevalence increased as socioeconomic status declined in all age groups. Identifying multimorbidity patterns associated with specific age-related life-stages allows health systems to prioritize and to adapt clinical management efforts by age group.Ministry of Science and Innovation through the Instituto Carlos III (ISCiii)ISCiii-RETICSISCiiiInstitut Universitari d’Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol
Study protocol of cost-effectiveness and cost-utility of a biopsychosocial multidisciplinary intervention in the evolution of non-specific sub-acute low back pain in the working population: cluster randomised trial.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain (LBP), with high incidence and prevalence rate, is one of the most common reasons to consult the health system and is responsible for a significant amount of sick leave, leading to high health and social costs. The objective of the study is to assess the cost-effectiveness and cost-utility analysis of a multidisciplinary biopsychosocial educational group intervention (MBEGI) of non-specific sub-acute LBP in comparison with the usual care in the working population recruited in primary healthcare centres. Methods/design:
The study design is a cost-effectiveness and cost-utility analysis of a MBEGI in comparison with the usual care of non-specific sub-acute LBP.Measures on effectiveness and costs of both interventions will be obtained from a cluster randomised controlled clinical trial carried out in 38 Catalan primary health care centres, enrolling 932 patients between 18 and 65 years old with a diagnosis of non-specific sub-acute LBP. Effectiveness measures are: pharmaceutical treatments, work sick leave (% and duration in days), Roland Morris disability, McGill pain intensity, Fear Avoidance Beliefs (FAB) and Golberg Questionnaires. Utility measures will be calculated from the SF-12. The analysis will be performed from a social perspective. The temporal horizon is at 3 months (change to chronic LBP) and 12 months (evaluate the outcomes at long term. Assessment of outcomes will be blinded and will follow the intention-to-treat principle. Discussion: We hope to demonstrate the cost-effectiveness and cost-utility of MBEGI, see an improvement in the patients' quality of life, achieve a reduction in the duration of episodes and the chronicity of non-specific low back pain, and be able to report a decrease in the social costs. If the intervention is cost-effectiveness and cost-utility, it could be applied to Primary Health Care Centres. Trial registration:
ISRCTN: ISRCTN5871969
Patrones de multimorbilidad en adultos jóvenes en Cataluña : un análisis de clústeres
Identificar los patrones de multimorbilidad en pacientes de 19-44 años atendidos en atención primaria en Cataluña en el año 2010. Estudio descriptivo transversal. Doscientos cincuenta y un centros de salud. Fueron 530.798 personas con multimorbilidad de 19-44 años. La multimorbilidad fue definida como la coexistencia de ≥2 diagnósticos de la Clasificación Internacional de Enfermedades registrados en la historia clínica informatizada. Los patrones de multimorbilidad fueron identificados a través de un análisis jerárquico de clústeres y descritos por sexo y grupos de edad (19-24 y 25-44 años). De las 882.708 personas de la población inicial, 530.798 (60,1%) presentaron multimorbilidad. La media de edad fue de 33,0 años (DT: 7,0) y el 53,3% fueron mujeres. La multimorbilidad fue más alta en el grupo de 25-44 años respecto al grupo más joven (60,5 vs. 58,1%, p < 0,001), siendo más alta en las mujeres. El clúster más prevalente en todos los estratos estuvo constituido por caries dental, tabaquismo, dorsalgia, resfriado común y otros trastornos de ansiedad. En ambos sexos, en los estratos de 25-44 años apareció el patrón cardiovascular-endocrino-metabólico (obesidad, dislipidemias e hipertensión arterial). La multimorbilidad afecta a más de la mitad de personas entre los 19-44 años de edad. El clúster más prevalente está formado por diagnósticos que agrupan enfermedades comunes (caries dental, resfriado común, tabaquismo, trastornos de ansiedad y dorsalgias). Otro patrón a destacar es el cardiovascular-endocrino-metabólico en el grupo de 25-44. El conocimiento de los patrones de multimorbilidad en adultos jóvenes permitiría un enfoque preventivo
The infectious synapse formed between mature dendritic cells and CD4 + T cells is independent of the presence of the HIV-1 envelope glycoprotein
Altres ajuts:This work was supported the Spanish AIDS Network (RD06/0006), the Catalan HIV Vaccine Development Program (HIVACAT), and the Spanish Foundation for AIDS Research and Prevention (FIPSE) project 36750/08.Since cell-mediated infection of human immunodeficiency virus type 1 (HIV-1) is more efficient than cell-free infection, cell-to-cell propagation plays a crucial role in the pathogenesis of HIV-1 infection. Transmission of HIV-1 is enabled by two types of cellular contacts, namely, virological synapses between productively infected cells and uninfected target cells and infectious synapses between uninfected dendritic cells (DC) harboring HIV-1 and uninfected target cells. While virological synapses are driven by expression of the viral envelope glycoprotein on the cell surface, little is known about the role of envelope glycoprotein during contact between DC and T cells. We explored the contribution of HIV-1 envelope glycoprotein, adhesion molecules, and antigen recognition in the formation of conjugates comprising mature DC (mDC) and CD4 + T cells in order to further evaluate their role in mDC-mediated HIV-1 transmission at the immunological synapse. Unlike virological synapse, HIV-1 did not modulate the formation of cell conjugates comprising mDC harboring HIV-1 and non-activated primary CD4 + T cells. Disruption of interactions between ICAM-1 and LFA-1, however, resulted in a 60% decrease in mDC-CD4 + T-cell conjugate formation and, consequently, in a significant reduction of mDC-mediated HIV-1 transmission to non-activated primary CD4 + T cells (p < 0.05). Antigen recognition or sustained MHC-TcR interaction did not enhance conjugate formation, but significantly boosted productive mDC-mediated transmission of HIV-1 (p < 0.05) by increasing T-cell activation and proliferation. Formation of the infectious synapse is independent of the presence of the HIV-1 envelope glycoprotein, although it does require an interaction between ICAM-1 and LFA-1. This interaction is the main driving force behind the formation of mDC-CD4 + T-cell conjugates and enables transmission of HIV-1 to CD4 + T cells. Moreover, antigen recognition boosts HIV-1 replication without affecting the frequency of cellular conjugates. Our results suggest a determinant role for immune activation driven by mDC-CD4 + T-cell contacts in viral dissemination and that this activation likely contributes to the pathogenesis of HIV-1 infection
Correction of tau mis-splicing caused by FTDP-17 MAPT mutations by spliceosome-mediated RNA trans-splicing
Frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) is caused by mutations in the MAPT gene, encoding the tau protein that accumulates in intraneuronal lesions in a number of neurodegenerative diseases. Several FTDP-17 mutations affect alternative splicing and result in excess exon 10 (E10) inclusion in tau mRNA. RNA reprogramming using spliceosome-mediated RNA trans-splicing (SMaRT) could be a method of choice to correct aberrant E10 splicing resulting from FTDP-17 mutations. SMaRT creates a hybrid mRNA through a trans-splicing reaction between an endogenous target pre-mRNA and a pre-trans-splicing RNA molecule (PTM). However, FTDP-17 mutations affect the strength of cis-splicing elements and could favor cis-splicing over trans-splicing. Excess E10 inclusion in FTDP-17 can be caused by intronic mutations destabilizing a stem-loop protecting the 5′ splice site at the E10/intron 10 junction. COS cells transfected with a minigene containing the intronic +14 mutation produce exclusively E10+ RNA. Generation of E10− RNA was restored after co-transfection with a PTM designed to exclude E10. Similar results were obtained with a target containing the exonic N279K mutation which strengthens a splicing enhancer within E10. Conversely, increase or decrease in E10 content was achieved by trans-splicing from a target carrying the Δ280K mutation, which weakens the same splicing enhancer. Thus E10 inclusion can be modulated by trans-splicing irrespective of the strength of the cis-splicing elements affected by FTDP-17 mutations. In conclusion, RNA trans-splicing could provide the basis of therapeutic strategies for impaired alternative splicing caused by pathogenic mutations in cis-acting splicing elements
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