95 research outputs found
Small-scale Interaction of Turbulence with Thermonuclear Flames in Type Ia Supernovae
Microscopic turbulence-flame interactions of thermonuclear fusion flames
occuring in Type Ia Supernovae were studied by means of incompressible direct
numerical simulations with a highly simplified flame description. The flame is
treated as a single diffusive scalar field with a nonlinear source term. It is
characterized by its Prandtl number, Pr << 1, and laminar flame speed, S_L. We
find that if S_L ~ u', where u' is the rms amplitude of turbulent velocity
fluctuations, the local flame propagation speed does not significantly deviate
from S_L even in the presence of velocity fluctuations on scales below the
laminar flame thickness. This result is interpreted in the context of
subgrid-scale modeling of supernova explosions and the mechanism for
deflagration-detonation-transitions.Comment: 8 pages, 6 figures, accepted by Astrophys.
Utilization and Adherence Patterns of Subcutaneously Administered Anti–Tumor Necrosis Factor Treatment Among Rheumatoid Arthritis Patients
AbstractBackgroundAdherence to therapy is a key requirement underlying achievement of clinical outcomes in randomized controlled drug registration trials. In postmarketing studies, comparison of adherence among therapies can become more complicated when drug dosing and administration schedules differ or when methods used to measure adherence are not consistently applied.ObjectiveThe objective of this exploratory study was to investigate a broad range of utilization and adherence outcomes associated with subcutaneous biologic treatments for rheumatoid arthritis (RA).MethodsAdult patients (aged ≥18 years) exhibiting ≥2 claims with an RA diagnosis (code 714.x), at least 24 months of continuous medical and pharmacy eligibility, and 30-day supplies of adalimumab, etanercept, or golimumab were selected from the Optum Insight Clinformatics database. Adherence and utilization measures were calculated and compared across treatment groups.ResultsA total of 1532 adalimumab, 2099 etanercept, and 261 golimumab patients met inclusion criteria. Compared with both adalimumab and etanercept patients, golimumab patients were significantly more likely to have a medication possession ratio of ≥0.80 (82% vs 71% vs 62%; P < 0.001) and significantly less likely to have ≥4 late medication refills (6.9% vs 17.7% vs 26.1%; P < 0.001 for all). Etanercept patients had significantly greater refill intervals (37.7 vs 34.9 and 35.1 days) and had the lowest proportion of adherent fills (70% vs 77% and 75%) compared with both golimumab and adalimumab patients (P < 0.001 for all). Bivariate effects were reproduced in multivariate models that controlled for treatment duration.ConclusionsA number of statistically significant medication adherence differences were observed among golimumab, adalimumab, and etanercept patients in treatment for RA. Overall, golimumab patients appeared to be the most adherent group. Findings may be partially attributable to golimumab patients’ likely increased disease severity, their prior experience with biologic medication, or golimumab’s once-monthly dosing schedule, which requires fewer administrations than both adalimumab and etanercept
Evaluación de la producción de hidrógeno y metano a partir de datos sobre residuos sólidos domiciliarios de la ciudad de Buenos Aires
El objetivo de este trabajo es aportar al estudio energético y de emisión de contaminantes de combustibles obtenidos a partir de biomasa. Utilizando datos de inventarios disponibles de biomasa en residuos sólidos domiciliarios, se calculó el substrato metabolizable por microorganismos para la obtención de CH4 e H2. Se determinó el contenido teórico de energÃa de los combustibles obtenidos y se evaluaron las emisiones de CO2 producidas durante la generación y la combustión de ambos gases. Los resultados indican que la energÃa disponible a partir de la obtención de CH4 es un 10% superior que la obtenida a partir del H2. En sentido inverso las emisiones de CO2 disminuyen considerablemente (33%) en los procesos que involucran H2. Ambas alternativas resultan beneficiosas si son comparadas con el enterramiento de la biomasa. La emisión de metano, en toneladas de CO2 equivalente, es aproximadamente 6 veces la emisión correspondiente a la opción de generación y utilización de CH4.The objective of this work is to contribute to the energy study and to the analysis of pollutants emission of fuels, obtained from biomass. Using data of available inventories of biomass in domiciliary solid residuals, the substratum metabolizable by microorganisms for the obtaining of CH4 and H2 was calculated. The theoretical energy content of the obtained fuels was determined, and the CO2 emissions which take place during the generation and the combustion of both gases were evaluated. Results indicate that the available energy from the obtained CH4 is 10% higher than the available energy from the obtained H2. Conversely, CO2 emissions during the processes that involve H2 are considerably reduced (around 33%). Both alternatives are beneficial if they are compared with the biomass burial. The methane emission of the buried biomass, measured as equivalent tons of CO2, is approximately 6 times the emission corresponding to the alternative of generation and use of CH4.Asociación Argentina de EnergÃas Renovables y Medio Ambiente (ASADES
DNA-dependent Protein Kinase Activity Is Not Required for Immunoglobulin Class Switching
Class switch recombination (CSR), similar to V(D)J recombination, is thought to involve DNA double strand breaks and repair by the nonhomologous end–joining pathway. A key component of this pathway is DNA-dependent protein kinase (DNA-PK), consisting of a catalytic subunit (DNA-PKcs) and a DNA-binding heterodimer (Ku70/80). To test whether DNA-PKcs activity is essential for CSR, we examined whether IgM+ B cells from scid mice with site-directed H and L chain transgenes were able to undergo CSR. Although B cells from these mice were shown to lack DNA-PKcs activity, they were able to switch from IgM to IgG or IgA with close to the same efficiency as B cells from control transgenic and nontransgenic scid/+ mice, heterozygous for the scid mutation. We conclude that CSR, unlike V(D)J recombination, can readily occur in the absence of DNA-PKcs activity. We suggest nonhomologous end joining may not be the (primary or only) mechanism used to repair DNA breaks during CSR
Statistics of Dissipation and Enstrophy Induced by a Set of Burgers Vortices
Dissipation and enstropy statistics are calculated for an ensemble of
modified Burgers vortices in equilibrium under uniform straining. Different
best-fit, finite-range scaling exponents are found for locally-averaged
dissipation and enstrophy, in agreement with existing numerical simulations and
experiments. However, the ratios of dissipation and enstropy moments supported
by axisymmetric vortices of any profile are finite. Therefore the asymptotic
scaling exponents for dissipation and enstrophy induced by such vortices are
equal in the limit of infinite Reynolds number.Comment: Revtex (4 pages) with 4 postscript figures included via psfi
Gastrointestinal symptoms and association with medication use patterns, adherence, treatment satisfaction, quality of life, and resource use in osteoporosis: baseline results of the MUSIC-OS study
Summary: The Medication Use Patterns, Treatment Satisfaction, and Inadequate Control of Osteoporosis Study (MUSIC-OS) is a prospective, observational study of women with osteoporosis in Europe and Canada. At baseline, patients with gastrointestinal symptoms reported lower adherence to osteoporosis treatment, treatment satisfaction, and health-related quality of life, than those without gastrointestinal symptoms. Introduction: The aim of the study was to examine gastrointestinal (GI) symptoms and the association between GI symptoms and treatment adherence, treatment satisfaction, and health-related quality of life (HRQoL) among osteoporotic women in Europe and Canada. Methods: Baseline results are reported here for a prospective study which enrolled postmenopausal, osteoporotic women who were initiating (new users) or continuing (experienced users) osteoporosis treatment at study entry (baseline). A patient survey was administered at baseline and included the occurrence of GI symptoms during 6-month pre-enrolment, treatment adherence (adherence evaluation of osteoporosis (ADEOS), score 0–22), treatment satisfaction (Osteoporosis Treatment Satisfaction Questionnaire for Medications (OPSAT-Q), score 0–100) and HRQoL (EuroQol-5 dimension (EQ-5D) utility, score 0–1; OPAQ-SV, score 0–100). The association between GI symptoms and ADEOS (experienced users), OPSAT-Q (experienced users), and HRQoL (new and experienced users) was assessed by general linear models adjusted for patient characteristics. Results: A total of 2959 patients (2275 experienced and 684 new users) were included. Overall, 68.1 % of patients experienced GI symptoms in the past 6 months. Compared with patients without GI symptoms, patients with GI symptoms had lower mean baseline scores on most measures. The mean adjusted differences were ADEOS, −0.43; OPSAT-Q, −5.68; EQ-5D, −0.04 (new users) and −0.06 (experienced users), all P < 0.01. GI symptoms were also associated with lower OPAQ-SV domain scores: physical function, −4.17 (experienced users); emotional status, −4.28 (new users) and −5.68 (experienced users); back pain, −5.82 (new users) and −11.33 (experienced users), all P < 0.01. Conclusions: Patients with GI symptoms have lower treatment adherence and treatment satisfaction and worse HRQoL than patients without GI symptoms
- …