71 research outputs found
Prediction of residual stresses in girth welded pipes using an artificial neural network approach
Management of operating nuclear power plants greatly relies on structural integrity assessments for safety critical pressure vessels and piping components. In the present work, residual stress profiles of girth welded austenitic stainless steel pipes are characterised using an artificial neural network approach. The network has been trained using residual stress data acquired from experimental measurements found in literature. The neural network predictions are validated using experimental measurements undertaken using neutron diffraction and the contour method. The approach can be used to predict through-wall distribution of residual stresses over a wide range of pipe geometries and welding parameters thereby finding potential applications in structural integrity assessment of austenitic stainless steel girth welds
Checkerboard local density of states in striped domains pinned by vortices
Within a Green's function formalism we calculate the electronic structure
around static extended magnetic and non-magnetic perturbations in a d-wave
superconductor. In partucular, we discuss recent elastic neutron scattering and
scanning tunneling experiments on High-T_c cuprates exposed to an applied
magnetic field. A physical picture consisting of antiferromagnetic vortex cores
operating as pinning centers for surrounding stripes is qualitatively
consistent with the neutron data provided the stripes have the usual antiphase
modulation. The low energy electronic structure in such a region reveals a
checkerboard interference pattern consistent with recent scanning tunneling
experiments.Comment: 5 pages, 4 figure
Cell shape analysis of random tessellations based on Minkowski tensors
To which degree are shape indices of individual cells of a tessellation
characteristic for the stochastic process that generates them? Within the
context of stochastic geometry and the physics of disordered materials, this
corresponds to the question of relationships between different stochastic
models. In the context of image analysis of synthetic and biological materials,
this question is central to the problem of inferring information about
formation processes from spatial measurements of resulting random structures.
We address this question by a theory-based simulation study of shape indices
derived from Minkowski tensors for a variety of tessellation models. We focus
on the relationship between two indices: an isoperimetric ratio of the
empirical averages of cell volume and area and the cell elongation quantified
by eigenvalue ratios of interfacial Minkowski tensors. Simulation data for
these quantities, as well as for distributions thereof and for correlations of
cell shape and volume, are presented for Voronoi mosaics of the Poisson point
process, determinantal and permanental point processes, and Gibbs hard-core and
random sequential absorption processes as well as for Laguerre tessellations of
polydisperse spheres and STIT- and Poisson hyperplane tessellations. These data
are complemented by mechanically stable crystalline sphere and disordered
ellipsoid packings and area-minimising foam models. We find that shape indices
of individual cells are not sufficient to unambiguously identify the generating
process even amongst this limited set of processes. However, we identify
significant differences of the shape indices between many of these tessellation
models. Given a realization of a tessellation, these shape indices can narrow
the choice of possible generating processes, providing a powerful tool which
can be further strengthened by density-resolved volume-shape correlations.Comment: Chapter of the forthcoming book "Tensor Valuations and their
Applications in Stochastic Geometry and Imaging" in Lecture Notes in
Mathematics edited by Markus Kiderlen and Eva B. Vedel Jense
Quantum interference between multiple impurities in anisotropic superconductors
We study the quantum interference between impurities in d-wave
superconductors within a potential scattering formalism that easily applies to
multiple impurities. The evolution of the low-energy local density of states
for both magnetic and nonmagnetic short-ranged scatterers are studied as a
function of the spatial configuration of the impurities. Further we discuss the
influence of subdominant bulk superconducting order parameters on the
interference pattern from multiple impurities.Comment: 4 pages, 6 figure
The Technological culture of war
The article proceeds from the argument that war is a social institution and not a historical inevitability of human interaction,
that is, war can be “unlearned.” This process involves deconstructing/dismantling war as an institution in
society. An important step in this process is to understand the philosophical and cultural bases on which technology
is employed as “tools” of war. The article focuses on such questions as, Is technology just viewed as instruments in
the hand of its human masters in war? Does technology take on an autonomous role in war? How should we assess
the impact of context (political, economic, and cultural) of technology when employed in war? By exploring these
points, the article hopes to provide input into the discussion on the control of war technologies and ultimately the dismantling
of war as an institution in society
Evaluation of basil extract ( Ocimum basilicum L.) on oxidative, anti-genotoxic and anti-inflammatory effects in human leukocytes cell cultures exposed to challenging agents
ABSTRACT Ocimum is one of the most important genera of the Lamiaceae family. Several studies about basil and its popular use reveal many characteristics of the herb, including its use as antioxidant, anti-aging, anti-inflammatory, anti-carcinogenic, anti-microbial, and cardiovascular agents, among others. In this paper, we evaluated genotoxic, oxidative, and anti-inflammatory parameters from the extract of Ocimum basilicum in different concentrations, using human leukocytes cultures exposed to challenging agents. Our results confirm that the O. basilicum extract acts as an antioxidant and effectively reverts or subjugates the effects of high oxidizing agents such as hydrogen peroxide. These actions are attributed to its composition, which is rich in polyphenols and flavonoids as well as compounds such as rosmarinic acid, all of which have well-known antioxidant activity. We also show that our basil extract presents anti-inflammatory properties, the mechanism of which is a composed interaction between the inhibition of pro-inflammatory mediator and the stimulation of anti-inflammatory cytokines. Although pharmacodynamics studies are necessary to evaluate the activities in vivo, our results demonstrated that basil could act as an antioxidant and anti-inflammatory and a possible alternative for medicinal treatment
Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2)
BACKGROUND:
Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control.
METHODS:
Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights.
FINDINGS:
5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease.
INTERPRETATION:
International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.</p
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