88 research outputs found
Impact Of Metabolic Health On Microvascular Endothelial Function In Morbidly Obese Qataris
No full textPrediction of Housing Location Price by a Multivariate Spatial Method: Cokriging
No full textCokriging is a multivariate spatial method to estimate spatial correlated variables. This method allows spatial estimations to be made and interpolated maps of house price to be created. These maps are interesting for appraisers, real estate companies, and bureaus because they provide an overview of location prices. Kriging uses one variable of interest (house price) to make estimates at unsampled locations, and cokriging uses the variable of interest and auxiliary correlated variables. In this paper, housing location price is estimated using kriging methods, isotopic data cokriging, and heterotopic data cokriging methods. The results of these methods are then compared.
Dynamic Modelling and Control of the Oil Market: An Economic Engineering Approach
No full textThis thesis develops dynamical state-space models of the oil market and suggests opportunities for the application of control theory. The emphasis of this thesis is on the modelling, rather than the control theory applications. Most models that are currently employed by oil companies do not model short-term transient responses, but focus on long-term equilibrium modelling. Short-term transient response modelling of oil-economic systems can benefit trading and supply activities of oil companies. The models that are provided in this thesis have the ability to model short-term transient responses, due to the their dynamical nature and economic basis. To obtain these models, this thesis uses economic engineering. Economic engineering is a discipline that models economic systems, using an analogy between economic variables and engineering variables. The model development in this thesis consists of three parts. First, a fundamental economic-engineering model is built that represents the global crude-oil market. The model forecasts crude-oil prices using global crude-oil production as an exogenous input. The parameters of this model are estimated using system identification. Second, this thesis provides specialized models for common oil-market phenomena within the economic-engineering framework. These include refinery modelling, geographic dispersion, the futures market and economic growth. Finally, this thesis suggests applications for control theory. For these applications, various controllers are discussed. The identified fundamental model yields positive first results that do no reject the validity of the modelling approach. Moreover, the specialized models provide satisfactory solutions for several oil market mechanisms.Mechanical Engineering | Systems and Contro
q-Differential equations for q-classical polynomials and q-Jacobi-Stirling numbers
No full textWe introduce, characterise and provide a combinatorial interpretation for the so-called q-Jacobi–Stirling numbers.
This study is motivated by their key role in the (reciprocal) expansion of any power of a second order
q-differential operator having the q-classical polynomials as eigenfunctions in terms of other even order operators,
which we explicitly construct in this work. The results here obtained can be viewed as the q-version of
those given by Everitt et al. and by the first author, whilst the combinatorics of this new set of numbers is a
q-version of the Jacobi–Stirling numbers given by Gelineau and the second author
Price dynamics in the oil market: a bond-graph modeling approach
No full textCurrent oil modeling techniques lack a comprehensive approach, as long-term oil prices are qualitatively modeled based on first principles, while short-term price transients are modeled using econometric methods. In this paper we propose a comprehensive bond-graph modeling approach in which price dynamics follow from first principles. The first principles that we use are derived from the recently developed economic-engineering theory in which price dynamics are modeled using Newtonian mechanics and price drivers are identified as forces. We reformulate a qualitative first-principles model developed by the Energy Information Administration (EIA) as a bond graph by modeling six identified price-driving factors as port-elements. The constitutive laws of these port-elements generate the price drivers, which through the interconnection structure of the bond graph yield the price dynamics. We demonstrate the bond-graph model by identifying its parameters and letting it estimate the oil price given historic oil supply data. Compared to a benchmark black-box model, we find that the bond graph has two advantages: (i) it achieves a better performance, and (ii) we know what its parameters and variables represent. The latter advantage allows us to validate the bond-graph model by reconstructing the oil inventory stocks and to manually adjust parameters by expert input.Team Bart De Schutte
Role of prostanoid IP and EP receptors in mediating vasorelaxant responses to PGI2 analogues in rat tail artery: Evidence for Gi/o modulation via EP3 receptors
No full textSigmoid Diverticulitis in a tight spot: an atypical presentation within a ventral hernia
No full textCopyright © 2023, Ezeme et al.
This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Ventral hernia and acute diverticulitis may present with similar symptoms posing difficulty in clinical diagnosis. Rarely, complicated sigmoid diverticulitis is found within an irreducible ventral hernia sac in the emergency setting. Intraoperative decision on the appropriate surgical option depends on the surgeon’s experience and the patient’s clinical state. We present a case of a middle-aged female who came in with infraumbilical hernia containing necrotic sigmoid diverticulitis. Her surgical history was cesarean section and total abdominal hysterectomy with a re-look laparotomy. She had an emergency exploration of the hernia through a midline incision, excision of the necrotic diverticulum, and the formation of loop colostomy at the site of the hernia. Post-operative recovery was uneventful and she has been scheduled for an elective sigmoid colectomy and reversal of the stoma. This study highlights that complicated sigmoid diverticulitis can rarely present as an irreducible ventral hernia and that less is often more in safely getting patients out of trouble in an emergency.https://www.cureus.com/articles/211974-sigmoid-diverticulitis-in-a-tight-spot-an-atypical-presentation-within-a-ventral-hernia#!
Geography of Gender and its Perspectives and Issues on Urban Space : Comparative Review of Anglophone countries and Japan
No full textIn this paper, the author examines development of feminist geography in Anglophone countries and discusses on the Japanese urban geography focusing on gender issue. In the 1980s, feminist geographers in Anglophone countries have tackled male hegemony, which has dominated the scholarship, and focused on the home and the local community, which have not been paid attention. It was clarified that women playing the housework had been limited to choose their occupation in a dichotomy. After the 1990s, with the increase of the entry by women into labor market, polarization of female labour force, the urban structure of dichotomy changes and gender interests other dimensions such as race, religion, nationality, and class become a material issue. Feminist geographers find the shift from politics of “redistribution” to politics of “recognition”.After the 1990s, with diversification of family and feminization of labor force, some Japanese urban geographers have come to pay attentions to women. However, they have only paid little attentions to reproductive labour, such as community activity or housework. In other words, beca
use some geographers catch women as objects, the private sphere in the urban space is still invisible. We should encompass not only women’s paid work, but also unpaid or voluntary work in terms of both ‘economic’redistribution and ‘social’ recognition to scrutinize transforming suburban space
La Audiencia ante los Medios
No full textEstudio que presenta el desarrollo histórico de las teorías de la interpretación de la audiencia. El primer enfoque es el de los Estudios Críticos Culturales Anglo-americanos, luego se describe el enfoque de las mediaciones que analiza las fuentes y los tipos de mediación, la evolución de la Publicidad y su influencia en las investigaciones de recepción, y por último se aborda el Postmodernismo con una corriente interpretativa de la teoría de las audiencias.AbstractThis study present the historical development of the theories of audience interpretation. The author first focuses on critical studies of anglo-american cultures. he then describes the different types of mediation theories and their origins followed by the growth in advertising and its influence on studies of reception. He concludees with postmodernism as a current interpretation of the audience theory.RésuméCette étude résume l'évolution des théories de l'interpétation des audiences. L'auteur décrit successivement les études critiques culturelles angloaméricaines, la théorie des médiations à partir de leurs sources et de leur tipologie, l'évolution de la plublicité et de son influence sur les études de réception et enfin la postmodernité en tant qu'interprétation de la théorie des audiences
Increased intracellular reactive oxygen species in patients with end-stage renal failure: Effect of hemodialysis
No full textIncreased intracellular reactive oxygen species in patients with end-stage renal failure: Effect of hemodialysis.BackgroundReactive oxygen species (ROS) have been implicated in various forms of cellular injury. ROS may cause cell damage and are involved in the pathophysiology of several diseases, including atherosclerosis and chronic inflammation.MethodsDisturbances of intracellular ROS levels were investigated in 28 patients with end-stage renal failure. The intracellular ROS levels were measured in lymphocytes before and after hemodialysis using biocompatible membranes and were compared with those from 11 patients with end-stage renal failure, not yet on renal replacement therapy, and 27 healthy control subjects. ROS levels were measured spectrophotometrically using the intracellular dye dichlorofluorescin diacetate.ResultsThe spontaneous production of ROS was significantly higher in lymphocytes from patients with end-stage renal failure compared with healthy control subjects (P < 0.01). The addition of 100 nmol/L phorbol-myristate-acetate (PMA) produced a significant increase of ROS, both in lymphocytes from patients with end-stage renal failure and healthy control subjects. The PMA-induced ROS increase was significantly higher in lymphocytes from patients with end-stage renal failure compared with healthy control subjects (P < 0.01). In patients with end-stage renal failure, not yet on renal replacement therapy, the PMA-induced ROS was also significantly higher compared with healthy control subjects. The PMA-induced ROS increases were significantly inhibited by catalase, but not by superoxide dismutase or the superoxide dismutase mimetic, tempol. PMA-induced ROS was significantly reduced by tyrphostin A51 in lymphocytes from patients with end-stage renal failure and from healthy control subjects (each P < 0.01), indicating the involvement of a tyrosine kinase-dependent pathway. In patients with end-stage renal failure, the spontaneous and the PMA-induced production of ROS was not significantly different before and after hemodialysis.ConclusionsRegular hemodialysis sessions using biocompatible membranes have no effect on the elevated intracellular ROS in patients with end-stage renal failure
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