411 research outputs found
Enhanced error estimator based on a nearly equilibrated moving least squares recovery technique for FEM and XFEM
In this paper a new technique aimed to obtain accurate estimates of the error
in energy norm using a moving least squares (MLS) recovery-based procedure is
presented. We explore the capabilities of a recovery technique based on an
enhanced MLS fitting, which directly provides continuous interpolated fields,
to obtain estimates of the error in energy norm as an alternative to the
superconvergent patch recovery (SPR). Boundary equilibrium is enforced using a
nearest point approach that modifies the MLS functional. Lagrange multipliers
are used to impose a nearly exact satisfaction of the internal equilibrium
equation. The numerical results show the high accuracy of the proposed error
estimator
Diverse histologic appearances in pulmonary mucinous cystic neoplasia: A case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Magnetic Anisotropic Energy Gap and Strain Effect in Au Nanoparticles
We report on the observation of the size effect of thermal magnetization in Au nanoparticles. The thermal deviation of the saturation magnetization departs substantially from that predicted by the Bloch T3/2-law, indicating the existence of magnetic anisotropic energy. The results may be understood using the uniaxial anisotropy Heisenberg model, in which the surface atoms give rise to polarized moments while the magnetic anisotropic energy decreases as the size of the Au nanoparticles is reduced. There is a significant maximum magnetic anisotropic energy found for the 6 nm Au nanoparticles, which is associated with the deviation of the lattice constant due to magnetocrystalline anisotropy
Patient Disease Perceptions and Coping Strategies for Arthritis in a Developing Nation: A Qualitative Study
<p>Abstract</p> <p>Background</p> <p>There is little prior research on the burden of arthritis in the developing world. We sought to document how patients with advanced arthritis living in the Dominican Republic are affected by and cope with their disease.</p> <p>Methods</p> <p>We conducted semi-structured, one-to-one interviews with economically disadvantaged Dominican patients with advanced knee and/or hip arthritis in the Dominican Republic. The interviews, conducted in Spanish, followed a moderator's guide that included topics such as the patients' understanding of disease etiology, their support networks, and their coping mechanisms. The interviews were audiotaped, transcribed verbatim in Spanish, and systematically analyzed using content analysis. We assessed agreement in coding between two investigators.</p> <p>Results</p> <p>18 patients were interviewed (mean age 60 years, median age 62 years, 72% women, 100% response rate). Patients invoked religious and environmental theories of disease etiology, stating that their illness had been caused by God's will or through contact with water. While all patients experienced pain and functional limitation, the social effects of arthritis were gender-specific: women noted interference with homemaking and churchgoing activities, while men experienced disruption with occupational roles. The coping strategies used by patients appeared to reflect their beliefs about disease causation and included prayer and avoidance of water.</p> <p>Conclusions</p> <p>Patients' explanatory models of arthritis influenced the psychosocial effects of the disease and coping mechanisms used. Given the increasing reach of global health programs, understanding these culturally influenced perceptions of disease will be crucial in successfully treating chronic diseases in the developing world.</p
Differential Analysis of Ovarian and Endometrial Cancers Identifies a Methylator Phenotype
Despite improved outcomes in the past 30 years, less than half of all women diagnosed with epithelial ovarian cancer live five years beyond their diagnosis. Although typically treated as a single disease, epithelial ovarian cancer includes several distinct histological subtypes, such as papillary serous and endometrioid carcinomas. To address whether the morphological differences seen in these carcinomas represent distinct characteristics at the molecular level we analyzed DNA methylation patterns in 11 papillary serous tumors, 9 endometrioid ovarian tumors, 4 normal fallopian tube samples and 6 normal endometrial tissues, plus 8 normal fallopian tube and 4 serous samples from TCGA. For comparison within the endometrioid subtype we added 6 primary uterine endometrioid tumors and 5 endometrioid metastases from uterus to ovary. Data was obtained from 27,578 CpG dinucleotides occurring in or near promoter regions of 14,495 genes. We identified 36 locations with significant increases or decreases in methylation in comparisons of serous tumors and normal fallopian tube samples. Moreover, unsupervised clustering techniques applied to all samples showed three major profiles comprising mostly normal samples, serous tumors, and endometrioid tumors including ovarian, uterine and metastatic origins. The clustering analysis identified 60 differentially methylated sites between the serous group and the normal group. An unrelated set of 25 serous tumors validated the reproducibility of the methylation patterns. In contrast, >1,000 genes were differentially methylated between endometrioid tumors and normal samples. This finding is consistent with a generalized regulatory disruption caused by a methylator phenotype. Through DNA methylation analyses we have identified genes with known roles in ovarian carcinoma etiology, whereas pathway analyses provided biological insight to the role of novel genes. Our finding of differences between serous and endometrioid ovarian tumors indicates that intervention strategies could be developed to specifically address subtypes of epithelial ovarian cancer
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Efficacy of interventions to increase the uptake of chlamydia screening in primary care: a systematic review
<p>Abstract</p> <p>Background</p> <p>As most genital chlamydia infections are asymptomatic, screening is the main way to detect and cases for treatment. We undertook a systematic review of studies assessing the efficacy of interventions for increasing the uptake of chlamydia screening in primary care.</p> <p>Methods</p> <p>We reviewed studies which compared chlamydia screening in the presence and the absence of an intervention. The primary endpoints were screening rate or total tests.</p> <p>Results</p> <p>We identified 16 intervention strategies; 11 were randomised controlled trials and five observational studies, 10 targeted females only, five both males and females, and one males only. Of the 15 interventions among females, six were associated with significant increases in screening rates at the 0.05 level including a multifaceted quality improvement program that involved provision of a urine jar to patients at registration (44% in intervention clinics vs. 16% in the control clinic); linking screening to routine Pap smears (6.9% vs. 4.5%), computer alerts for doctors (12.2% vs. 10.6%); education workshops for clinic staff; internet-based continuing medical education (15.5% vs. 12.4%); and free sexual health consultations (16.8% vs. 13.2%). Of the six interventions targeting males, two found significant increases including the multifaceted quality improvement program in which urine jars were provided to patients at registration (45% vs. 15%); and the offering by doctors of a test to all presenting young male clients, prior to consultation (29 vs. 4%).</p> <p>Conclusions</p> <p>Interventions that promoted the universal offer of a chlamydia test in young people had the greatest impact on increasing screening in primary care.</p
Magnetotransport in an aluminum thin film on a GaAs substrate grown by molecular beam epitaxy
Magnetotransport measurements are performed on an aluminum thin film grown on a GaAs substrate. A crossover from electron- to hole-dominant transport can be inferred from both longitudinal resistivity and Hall resistivity with increasing the perpendicular magnetic field B. Also, phenomena of localization effects can be seen at low B. By analyzing the zero-field resistivity as a function of temperature T, we show the importance of surface scattering in such a nanoscale film
Why Are There So Few Rickettsia conorii conorii-Infected Rhipicephalus sanguineus Ticks in the Wild?
The bacterium Rickettsia conorii conorii is the etiological agent of Mediterranean spotted fever (MSF), which is a life-threatening infectious disease that is transmitted by Rhipicephalus sanguineus, the brown dog tick. Rh. sanguineus-R. conorii conorii relationships in the wild are still poorly understood one century after the discovery of the disease. In this study, we collected naturally infected ticks from the houses of people afflicted by MSF in Algeria. Colonies of both infected and non-infected ticks were maintained in our laboratory, and we studied the effect of temperature variations on the infected and non-infected ticks. We did not observe any major differences between the biological life cycle of the infected and non-infected ticks held at 25°C. However, a comparatively higher mortality relative to the control group was noticed when R. conorii conorii-infected engorged nymphs and adults were exposed to a low temperature (4°C) or high temperature (37°C) for one month and transferred to 25°C. R. conorii conorii-infected Rh. sanguineus may maintain and serve as reservoirs for the Rickettsia if they are not exposed to cold temperatures. New populations of ticks might become infected with Rickettsiae when feeding on a bacteremic animal reservoir
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