53 research outputs found
Conventional and Multiscale Modeling of Microstructure Evolution During Laminar Cooling of DP Steel Strips
On mathematical aspects of evolution of dislocation density in metallic materials
This paper deals with the solution of delay differential equations describing
evolution of dislocation density in metallic materials. Hardening, restoration,
and recrystallization characterizing the evolution of dislocation populations
provide the essential equation of the model. The last term transforms ordinary
differential equation (ODE) into delay differential equation (DDE) with strong
(in general, H\"older) nonlinearity. We prove upper error bounds for the
explicit Euler method, under the assumption that the right-hand side function
is H\"older continuous and monotone which allows us to compare accuracy of
other numerical methods in our model (e.g. Runge-Kutta), in particular when
explicit formulas for solutions are not known. Finally, we test the above
results in simulations of real industrial process
Driver mutations of pancreatic cancer affect signaling and ATP production
Glandular pancreatic epithelia of the acinar or ductal phenotype may seem terminally differentiated, but they are characterized by remarkable cell plasticity. Stress-induced trans-differentiation of these cells has been implicated in the mechanisms of carcinogenesis. Current consensus links pancreatic ductal adenocarcinoma with onco-transformation of ductal epithelia, but under the presence of driver mutations in Kras and Trp53, also with trans-differentiation of pancreatic acini. However, we do not know when, in the course of cancer progression, physiological functions are lost by mutant acinar cells, nor can we assess their capacity for the production of pancreatic juice components. Here, we investigated whether two mutationsâ and âpresent simultaneously in acinar cells of KPC mice (model of oncogenesis) influence cytosolic Ca2+ signals. Since signals control the cellular handling of digestive hydrolases, any changes that affect intracellular signaling events and cell bioenergetics might have an impact on the physiology of the pancreas. Our results showed that physiological doses of acetylcholine evoked less regular oscillations in KPC acinar cells compared to the control, whereas responses to supramaximal concentrations were markedly reduced. Menadione elicited signals of different frequencies in KPC cells compared to control cells. Finally, extrusion rates were significantly inhibited in KPC cells, likely due to the lower basal respiration and ATP production. Cumulatively, these findings suggest that driver mutations affect the signaling capacity of pancreatic acinar cells even before the changes in the epithelial cell morphology become apparent
Selected mesoeconomic indicators of regional development in Poland based on intermunicipal cooperation
PURPOSE: The aim of the study was to identify the mesoeconomic determinants of regional
development in Poland based on intermunicipal cooperation.DESIGN/METHODOLOGY/APPROACH: The research used analytical methods, including the local
development index, determined for Polish local government units (municipalities) in 2008-
2014, subsequently evaluated in 2015-2019. Moreover, in programming the inter-municipal
cooperation model, the method of diagnostic survey, comparative and descriptive analysis
was applied.FINDINGS: There is need for a way of regional development modeling based not only on
competitiveness indicators (such as the aggregate Local Development Index), but also on a
paradigm of partnership and differentiated cooperation conditions in functional areas.PRACTICAL IMPLICATIONS: The Local Development Index can provide a starting point for
programming alternative developments in the functional areas. At least two local
development roadmaps can be used in practice. First, the idea of homogeneous areas
development, programming the growth of socio-economic cohesion at territorial meso-level.
Second, the idea for areas with natural spatial and settlement diversity, conscious
maintenance of diversity.ORIGINALITY/VALUE: In this study, on the case of Polish municipalities, selected quantitative
and qualitative factors of local development were assessed. It was confirmed that the influence of "traditional" competitiveness factors is decreasing. However, the development
potential of municipalities and functional areas increases when the important role of
intermunicipal cooperation factors and the partnership paradigm is recognized. The
partnership model has a specific format, unique for each functional area or municipality,
therefore it needs to be programmed, applied and evaluated.peer-reviewe
Newly identified climatically and environmentally significant high-latitude dust sources
Peer reviewe
Newly identified climatically and environmentally significant high-latitude dust sources
Dust particles from high latitudes have a potentially large local, regional, and global significance to climate and the environment as short-lived climate forcers, air pollutants, and nutrient sources. Identifying the locations of local dust sources and their emission, transport, and deposition processes is important for understanding the multiple impacts of high-latitude dust (HLD) on the Earth\u27s systems. Here, we identify, describe, and quantify the source intensity (SI) values, which show the potential of soil surfaces for dust emission scaled to values 0 to 1 concerning globally best productive sources, using the Global Sand and Dust Storms Source Base Map (G-SDS-SBM). This includes 64 HLD sources in our collection for the northern (Alaska, Canada, Denmark, Greenland, Iceland, Svalbard, Sweden, and Russia) and southern (Antarctica and Patagonia) high latitudes. Activity from most of these HLD sources shows seasonal character. It is estimated that high-latitude land areas with higher (SIââ„0.5), very high (SIââ„0.7), and the highest potential (SIââ„0.9) for dust emission cover >1â670â000âkm, >560â000âkm, and >240â000âkm, respectively. In the Arctic HLD region (â„60âN), land area with SIââ„0.5 is 5.5â% (1â035â059âkm), area with SIââ„0.7 is 2.3â% (440â804âkm), and area with SIââ„0.9 is 1.1â% (208â701âkm). Minimum SI values in the northern HLD region are about 3 orders of magnitude smaller, indicating that the dust sources of this region greatly depend on weather conditions. Our spatial dust source distribution analysis modeling results showed evidence supporting a northern HLD belt, defined as the area north of 50âN, with a âtransitional HLD-source areaâ extending at latitudes 50â58ââN in Eurasia and 50â55âN in Canada and a âcold HLD-source areaâ including areas north of 60âN in Eurasia and north of 58âN in Canada, with currently âno dust sourceâ area between the HLD and low-latitude dust (LLD) dust belt, except for British Columbia. Using the global atmospheric transport model SILAM, we estimated that 1.0â% of the global dust emission originated from the high-latitude regions. About 57â% of the dust deposition in snow- and ice-covered Arctic regions was from HLD sources. In the southern HLD region, soil surface conditions are favorable for dust emission during the whole year. Climate change can cause a decrease in the duration of snow cover, retreat of glaciers, and an increase in drought, heatwave intensity, and frequency, leading to the increasing frequency of topsoil conditions favorable for dust emission, which increases the probability of dust storms. Our study provides a step forward to improve the representation of HLD in models and to monitor, quantify, and assess the environmental and climate significance of HLD
Experimental and theoretical studies of nanofluid thermal conductivity enhancement: a review
Nanofluids, i.e., well-dispersed (metallic) nanoparticles at low- volume fractions in liquids, may enhance the mixture's thermal conductivity, knf, over the base-fluid values. Thus, they are potentially useful for advanced cooling of micro-systems. Focusing mainly on dilute suspensions of well-dispersed spherical nanoparticles in water or ethylene glycol, recent experimental observations, associated measurement techniques, and new theories as well as useful correlations have been reviewed
Abstracts of presentations on plant protection issues at the xth international congress of virology: August 11-16,1996 Binyanei haOoma, Jerusalem, Israel Part 2 Plenary Lectures
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and â„1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (nâ=â5069) or prospectively (nâ=â5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (â€6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; pâ=â0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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