711 research outputs found
Finite-size scaling and deconfinement transition: the case of 4D SU(2) pure gauge theory
A recently introduced method for determining the critical indices of the
deconfinement transition in gauge theories, already tested for the case of 3D
SU(3) pure gauge theory, is applied here to 4D SU(2) pure gauge theory. The
method is inspired by universality and based on the finite size scaling
behavior of the expectation value of simple lattice operators, such as the
plaquette. We obtain an accurate determination of the critical index , in
agreement with the prediction of the Svetitsky-Yaffe conjecture.Comment: 11 pages, 3 eps figure
Optimal design of interfaces in a femoral head surface replacement prosthesis considering nonlinear behaviour
Shape optimization problems applied in the field of biomechanics are presented. Particularly the shape optimization of interfaces separating the bone tissue from the orthopaedic implant are considered. Nonlinear interface behaviour is included in the computational models: a nonlinear elastic model and a damage based model. For the two nonlinear interface constitutive laws an analytical shape sensitivity formulation has been developed. The objective functions included both the effect of the interface stresses and of the interface micromotions. The optimization procedure provided optimal designs, which display better mechanical performance in terms of interface stresses and damage diffusion. [Author abstract; 26 Refs; In English
Optimal design of interfaces in a femoral head surface replacement prosthesis considering nonlinear behaviour
Shape optimization problems applied in the field of biomechanics are presented. Particularly the shape optimization of interfaces separating the bone tissue from the orthopaedic implant are considered. Nonlinear interface behaviour is included in the computational models: a nonlinear elastic model and a damage based model. For the two nonlinear interface constitutive laws an analytical shape sensitivity formulation has been developed. The objective functions included both the effect of the interface stresses and of the interface micromotions. The optimization procedure provided optimal designs, which display better mechanical performance in terms of interface stresses and damage diffusion. [Author abstract; 26 Refs; In English
Racial and Socioeconomic Disparities in Melanoma Incidence Rates in Georgia: 2000-2011
Background: The objective of this research was to investigate melanoma incidence rates and health outcomes in Georgia over time and by race, socio-economic status (SES), and gender.
Methods: Age-adjusted melanoma incidence rates were obtained from the Georgia Comprehensive Cancer Registry SEER*Stat Database (2000-2011). To compare incidence rates across counties, and public health districts and by race, SES and gender, maps were generated using Geographic Information Systems (GIS). A cluster analysis was performed by use of SaTScan, and maps were created to visualize clusters of melanoma cases.
Results: In Georgia, from 2000-2011, age-adjusted incidence rates for melanoma were higher among Whites than Blacks (28.0 vs. 1.1 per 100,000 population). For both races, high rates were found to be associated with high SES. For Whites, high rates were concentrated in urban areas relative to Blacks in rural areas. Clusters of melanoma incident cases were found mainly in the north central region of Georgia.
Conclusions: For Georgia, results for map comparisons are consistent with previous research findings that higher melanoma incidence rates are associated with high SES for Whites and, to a lesser extent, for Blacks. Melanoma interventions in Georgia should focus on urban White and rural Black at-risk populations, especially those with high SES
Simultaneous optical diagnostic velocity and scalar field by molecular tagging technique Stratified Flames View project
International audienc
Temporal Trends in Cardiovascular Hospital Discharges Following a Mass Chlorine Exposure Event in Graniteville, South Carolina
Background: On January 6, 2005, a train derailed in Graniteville, South Carolina, releasing nearly 60,000 kg of toxic chlorine gas. The disaster left nine people dead and was responsible for hundreds of hospitalizations and outpatient visits in the subsequent weeks. While chlorine gas primarily affects the respiratory tract, a growing body of evidence suggests that acute exposure may also cause vascular injury and cardiac toxicity. Here, we describe the incidence of cardiovascular hospitalizations among residents of the zip codes most affected by the chlorine gas plume, and compare the incidence of cardiovascular discharges in the years leading up to the event (2000â2004) to the incidence in the years following the event (2005â2014).
Methods: De-identified hospital discharge information was collected from the South Carolina Revenue and Fiscal Affairs Office for individuals residing in the selected zip codes for the years 2000 to 2014. A quasi-experimental study design was utilized with a population-level interrupted time series model to examine hospital discharge rates for Graniteville-area residents for three cardiovascular diagnoses: hypertension (HTN), acute myocardial infarction (AMI), and coronary heart disease (CHD). We used linear regression with autoregressive error correction to compare slopes for pre- and post-spill time periods. Data from the 2000 and 2010 censuses were used to calculate rates and to provide information on potential demographic shifts over the course of the study.
Results: A significant increase in hypertension-related hospital discharge rates was observed for the years following the Graniteville chlorine spill (slope 8.2, p \u3c 0.001). Concurrent changes to CHD and AMI hospital discharge rates were in the opposite direction (slopes â3.2 and â0.3, p \u3c 0.01 and 0.14, respectively). Importantly, the observed trend cannot be attributed to an aging population.
Conclusions: An unusual increase in hypertension-related hospital discharge rates in the area affected by the Graniteville chlorine spill contrasts with national and state-level trends. A number of factors related to the spill may be contributing the observation: disaster-induced hypertension, healthcare services access issues, and, possibly, chlorine-induced susceptibility to vascular pathologies. Due to the limitations of our data, we cannot determine whether the individuals who visited the hospital were the ones exposed to chlorine gas, however, the finding warrants additional research. Future studies are needed to determine the etiology of the increase and whether individuals exposed to chlorine are at a heightened risk for hypertensive heart disease
Turnitin_Accounting Software for MSMEs_Organizational and Personal Factors Based on TAM Theory
MEK inhibition leads to BRCA2 downregulation and sensitization to DNA damaging agents in pancreas and ovarian cancer models
Targeting the DNA damage response (DDR) in tumors with defective DNA repair
is a clinically successful strategy. The RAS/RAF/MEK/ERK signalling pathway is
frequently deregulated in human cancers. In this study, we explored the effects of
MEK inhibition on the homologous recombination pathway and explored the potential
for combination therapy of MEK inhibitors with DDR inhibitors and a hypoxia-activated
prodrug.
We studied effects of combining pimasertib, a selective allosteric inhibitor of
MEK1/2, with olaparib, a small molecule inhibitor of poly (adenosine diphosphate
[ADP]-ribose) polymerases (PARP), and with the hypoxia-activated prodrug
evofosfamide in ovarian and pancreatic cancer cell lines. Apoptosis was assessed
by Caspase 3/7 assay and protein expression was detected by immunoblotting.
DNA damage response was monitored with ÎłH2AX and RAD51 immunofluorescence
staining. In vivo antitumor activity of pimasertib with evofosfamide were assessed
in pancreatic cancer xenografts.
We found that BRCA2 protein expression was downregulated following pimasertib
treatment under hypoxic conditions. This translated into reduced homologous
recombination repair demonstrated by levels of RAD51 foci. MEK inhibition was
sufficient to induce formation of ÎłH2AX foci, suggesting that inhibition of this pathway
would impair DNA repair. When combined with olaparib or evofosfamide, pimasertib
treatment enhanced DNA damage and increased apoptosis. The combination of
pimasertib with evofosfamide demonstrated increased anti-tumor activity in BRCA
wild-type Mia-PaCa-2 xenograft model, but not in the BRCA mutated BxPC3 model.
Our data suggest that targeted MEK inhibition leads to impaired homologous
recombination DNA damage repair and increased PARP inhibition sensitivity in BRCA-
2 proficient cancers
Associations between neighborhood walkability and walking following residential relocation: Findings from Alberta's Tomorrow Project
IntroductionCross-sectional studies consistently find that the neighborhood built environment (e.g., walkability) is associated with walking. However, findings from the few existing longitudinal residential relocation studies that have estimated associations between changes in neighborhood built characteristics and walking are equivocal. The study objective was to estimate whether changes in neighborhood walkability resulting from residential relocation were associated with leisure, transportation, and total walking levels among adults.MethodsThis study included longitudinal data from the âAlberta's Tomorrow Projectââa province-wide cohort study (Alberta, Canada). The analysis included data collected at two time points (i.e., baseline and follow-up) from 5,977 urban adults. The International Physical Activity Questionnaire (IPAQ) captured self-reported walking. We estimated neighborhood walkability, an index capturing intersection, destination, and population counts for the 400 m Euclidean buffer around participants' homes. Using household postal codes reported at baseline and follow-up, we categorized participants into three groups reflecting residential relocation (ânon-movers:â n = 5,679; âmovers to less walkability:â n = 164, and; âmovers to more walkability:â n = 134). We used Inverse-Probability-Weighted Regression Adjustment to estimate differences [i.e., average treatment effects in the treated (ATET)] in weekly minutes of leisure, transportation, and total walking at follow-up between residential relocation groups, adjusting for baseline walking, sociodemographic characteristics, and walkability. The median time between baseline and follow-up was 2-years.ResultsThe three residential relocation groups mainly included women (61.6â67.2%) and had a mean age of between 52.2 and 55.7 years. Compared to ânon-moversâ (reference group), weekly minutes of transportation walking at follow-up was significantly lower among adults who moved to less walkable neighborhoods (ATET: â41.34, 95 CI: â68.30, â14.39; p < 0.01). We found no other statistically significant differences in walking between the groups.DiscussionOur findings suggest that relocating to less walkable neighborhoods could have detrimental effects on transportation walking to the extent of adversely affecting health. Public health strategies that counteract the negative impacts of low walkable neighborhoods and leverage the supportiveness of high walkable neighborhoods might promote more walking
- âŠ