scholarly journals From inference to design: A comprehensive framework for uncertainty quantification in engineering with limited information

2022 ◽  
Vol 165 ◽  
pp. 108210
Author(s):  
A. Gray ◽  
A. Wimbush ◽  
M. de Angelis ◽  
P.O. Hristov ◽  
D. Calleja ◽  
...  
Keyword(s):  
Uncertainty Quantification ◽  
Limited Information ◽  
Comprehensive Framework

scholarly journals Uncertainty Quantification, Model Calibration and Sensitivity

2021 ◽  
pp. 71-92
Author(s):  
Jakub Bijak ◽  
Jason Hilton
Keyword(s):  
Experimental Design ◽  
Uncertainty Quantification ◽  
Computational Models ◽  
Agent Based Models ◽  
Agent Based ◽  
Quantification Model ◽  
High Level ◽  
Comprehensive Framework ◽  
Shed Light

AbstractBetter understanding of the behaviour of agent-based models, aimed at embedding them in the broader, model-based line of scientific enquiry, requires a comprehensive framework for analysing their results. Seeing models as tools for experimenting in silico, this chapter discusses the basic tenets and techniques of uncertainty quantification and experimental design, both of which can help shed light on the workings of complex systems embedded in computational models. In particular, we look at: relationships between model inputs and outputs, various types of experimental design, methods of analysis of simulation results, assessment of model uncertainty and sensitivity, which helps identify the parts of the model that matter in the experiments, as well as statistical tools for calibrating models to the available data. We focus on the role of emulators, or meta-models – high-level statistical models approximating the behaviour of the agent-based models under study – and in particular, on Gaussian processes (GPs). The theoretical discussion is illustrated by applications to the Routes and Rumours model of migrant route formation introduced before.

Ultrastructural Changes in Tumor Cells During Human Peripheral Blood Monocyte-Mediated Cytotoxicity

1981 ◽  
Vol 39 ◽  
pp. 452-453
Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren
Keyword(s):  
Target Cell ◽  
Human Peripheral Blood ◽  
Mononuclear Phagocytes ◽  
Ultrastructural Changes ◽  
Target Cells ◽  
Limited Information ◽  
Blood Monocytes ◽  
Tumoricidal Activity ◽  
Activated State

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.

SEM and TEM observations of sperm development in the testis of the freshwater fish Oreochromis mossambicus

1990 ◽  
Vol 48 (3) ◽  
pp. 58-59
Author(s):  
Daryl A. Cornish ◽  
George L. Smit
Keyword(s):  
Morphological Characteristics ◽  
Oreochromis Mossambicus ◽  
Breeding Cycle ◽  
Limited Information ◽  
North West ◽  
The North ◽  
Sem And Tem ◽  
Sperm Development ◽  
Ultrastructural Characteristics ◽  
The University

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.

Analysis of photographic emulsions for High-Voltage Electron Microscopy

1993 ◽  
Vol 51 ◽  
pp. 452-453 ◽  
Author(s):  
James R. Kremer ◽  
Paul S. Furcinitti ◽  
Eileen O’Toole ◽  
J. Richard McIntosh
Keyword(s):  
Electron Microscope ◽  
Optical Density ◽  
High Voltage ◽  
Noise Power ◽  
Limited Information ◽  
Modulation Transfer ◽  
Transmission Microscopy ◽  
High Voltage Electron Microscopy ◽  
Voltage Range ◽  
Voltage Electron

Characteristics of electron microscope film emulsions, such as the speed, the modulation transfer function, and the exposure dependence of the noise power spectrum, have been studied for electron energies (80-100keV) used in conventional transmission microscopy. However, limited information is available for electron energies in the intermediate to high voltage range, 300-1000keV. Furthermore, emulsion characteristics, such as optical density versus exposure, for new or improved emulsions are usually only quoted by film manufacturers for 80keV electrons. The need for further film emulsion studies at higher voltages becomes apparent when searching for a film to record low dose images of radiation sensitive biological specimens in the frozen hydrated state. Here, we report the optical density, speed and relative resolution of a few of the more popular electron microscope films after exposure to 1MeV electrons.Three electron microscope films, Kodak S0-163, Kodak 4489, and Agfa Scientia 23D56 were tested with a JEOLJEM-1000 electron microscope operating at an accelerating voltage of 1000keV.

Histochemical and Ultrastructural Studies of the Digestive Epithelium in a Gastropod Gametolytic Organ

1980 ◽  
Vol 38 ◽  
pp. 568-569
Author(s):  
R. L. Reeder ◽  
S. H. Rogers ◽  
W. A. Shannon
Keyword(s):  
Acid Phosphatase ◽  
Genital Tract ◽  
Reproductive Tract ◽  
Ultrastructural Level ◽  
Conclusive Evidence ◽  
Digestive Organ ◽  
Limited Information ◽  
Ultrastructural Studies ◽  
Morphological Studies

Numerous morphological studies have dealt with the spermatheca of pulmonate gastropods. This globular organ, which is attached to the female portion of the reproductive tract by a long duct in these monoecious animals, has had various functions ascribed to it. Recent histochemical demonstrations of deoxyribonuclease, ribonuclease, protease, and acid phosphatase have provided, however, conclusive evidence that it is a digestive organ for the degradation of superfluous sperm and genital tract secretions. Only limited information concerning the spermatheca is available at the ultrastructural level, a fact providing the stimulus for the present study of this organ in Sonorella santaritana, a desert mountain snail from Arizona.

Efficacy of Adding Folic Acid to Foods

2012 ◽  
Vol 82 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Violeta Fajardo ◽  
Gregorio Varela-Moreiras
Keyword(s):  
Folic Acid ◽  
Age Groups ◽  
Nutritional Deficiencies ◽  
Physiological Status ◽  
Food Fortification ◽  
Limited Information ◽  
Dietary Recommendations ◽  
Nutritional Education ◽  
Food Composition Tables ◽  
Staple Foods

In the past, food fortification along with nutritional education and the decrease in food costs relative to income have proven successful in eliminating common nutritional deficiencies. These deficiencies such as goiter, rickets, beriberi, and pellagra have been replaced with an entirely new set of “emergent deficiencies” that were not previously considered a problem [e.g., folate and neural tube defects (NTDs)]. In addition, the different nutrition surveys in so-called affluent countries have identified “shortfalls” of nutrients specific to various age groups and/or physiological status. Complex, multiple-etiology diseases, such as atherosclerosis, diabetes, cancer, and obesity have emerged. Food fortification has proven an effective tool for tackling nutritional deficiencies in populations; but today a more reasonable approach is to use food fortification as a means to support but not replace dietary improvement strategies (i. e. nutritional education campaigns). Folic acid (FA) is a potential relevant factor in the prevention of a number of pathologies. The evidence linking FA to NTD prevention led to the introduction of public health strategies to increase folate intakes: pharmacological supplementation, mandatory or voluntary fortification of staple foods with FA, and the advice to increase the intake of folate-rich foods. It is quite contradictory to observe that, regardless of these findings, there is only limited information on food folate and FA content. Data in Food Composition Tables and Databases are scarce or incomplete. Fortification of staple foods with FA has added difficulty to this task. Globally, the decision to fortify products is left up to individual food manufacturers. Voluntary fortification is a common practice in many countries. Therefore, the “worldwide map of vitamin fortification” may be analyzed. It is important to examine if fortification today really answers to vitamin requirements at different ages and/or physiological states. The real impact of vitamin fortification on some key biomarkers is also discussed. An important question also to be addressed: how much is too much? It is becoming more evident that chronic excessive intakes may be harmful and a wide margin of safety seems to be a mandatory practice in dietary recommendations. Finally, the “risk/benefit” dilemma is also considered in the “new” FA-fortified world.

Vascular trauma of the hand – a systematic review

VASA ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 205-215 ◽  
Author(s):  
Uwe Wahl ◽  
Ingmar Kaden ◽  
Andreas Köhler ◽  
Tobias Hirsch
Keyword(s):  
Duplex Sonography ◽  
Vascular Trauma ◽  
Vascular Lesions ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Limited Information ◽  
Endovascular Interventions ◽  
Provocation Tests ◽  
Objective Basis ◽  
Allen Test

Abstract. Hypothenar or thenar hammer syndrome (HHS) and hand-arm vibration syndrome (HAVS) are diseases caused by acute or chronic trauma to the upper extremities. Since both diseases are generally related to occupation and are recognised as occupational diseases in most countries, vascular physicians need to be able to distinguish between the two entities and differentiate them from other diagnoses. A total of 867 articles were identified as part of an Internet search on PubMed and in non-listed occupational journals. For the analysis we included 119 entries on HHS as well as 101 papers on HAVS. A professional history and a job analysis were key components when surveying the patient’s medical history. The Doppler-Allen test, duplex sonography and optical acral pulse oscillometry were suitable for finding an objective basis for the clinical tests. In the case of HHS, digital subtraction angiography was used to confirm the diagnosis and plan treatment. Radiological tomographic techniques provided very limited information distal to the wrist. The vascular component of HAVS proved to be strongly dependent on temperature and had to be differentiated from the various other causes of secondary Raynaud’s phenomenon. The disease was medicated with anticoagulants and vasoactive substances. If these were not effective, a bypass was performed in addition to various endovascular interventions, especially in the case of HHS. Despite the relatively large number of people exposed, trauma-induced circulatory disorders of the hands can be observed in a comparatively small number of cases. For the diagnosis of HHS, the morphological detection of vascular lesions through imaging is essential since the disorder can be accompanied by critical limb ischaemia, which may require bypass surgery. In the case of HAVS, vascular and sensoneurological pathologies must be objectified through provocation tests. The main therapeutic approach to HAVS is preventing exposure.

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