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Ascorbic acid concentration is reduced in the secondary aqueous humour of glaucomatous patients

LEITE, Mauro T.; PRATA, Tiago S.; KERA, Clarissa Z.; MIRANDA, Denise V.; BARROS, Silvia B. de Moraes; MELO JR., Luiz A. S.
Fonte: WILEY-BLACKWELL PUBLISHING, INC Publicador: WILEY-BLACKWELL PUBLISHING, INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.07%
P>Background: We aimed to evaluate the ascorbic acid concentration in secondary aqueous humour (AH) from glaucomatous patients and to compare it with primary AH from primary open-angle glaucoma patients and non-glaucomatous patients. Methods: Primary AH samples were prospectively obtained from clinically uncontrolled primary open-angle glaucoma patients and senile cataract patients (controls) prior to trabeculectomy and cataract surgery. Secondary AH samples were obtained from eyes with previous intraocular surgery, prior to trabeculectomy or cataract surgery. AH (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber just before surgery and then immediately stored at -80 degrees C. The ascorbic acid concentration was determined in a masked fashion by high-pressure liquid chromatography. Results: A total of 18 patients with senile cataract, 16 glaucomatous patients with primary AH (no previous intraocular surgery) and 11 glaucomatous patients with secondary AH (previous intraocular surgery) were included. There was no difference in mean age between groups (P = 0.15). The mean +/- standard deviation concentration of ascorbic acid in the secondary AH from glaucomatous patients (504 +/- 213 mu mol/L [95% confidence interval {CI}...

Effect of dexmedetomidine on the minimum alveolar concentration of isoflurane in cats

Escobar, A.; Pypendop, B. H.; Siao, K. T.; Stanley, S. D.; Ilkiw, J. E.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 163-168
ENG
Relevância na Pesquisa
36.11%
This study reports the effects of dexmedetomidine on the minimum alveolar concentration of isoflurane (MAC iso) in cats. Six healthy adult female cats were used. MAC iso and dexmedetomidine pharmacokinetics had previously been determined in each individual. Cats were anesthetized with isoflurane in oxygen. Dexmedetomidine was administered intravenously using target-controlled infusions to maintain plasma concentrations of 0.16, 0.31, 0.63, 1.25, 2.5, 5, 10, and 20ng/mL. MAC iso was determined in triplicate at each target plasma dexmedetomidine concentration. Blood samples were collected and analyzed for dexmedetomidine concentration. The following model was fitted to the concentration-effect data: where MAC iso.c is MAC iso at plasma dexmedetomidine concentration C, MAC iso.0 is MAC iso in the absence of dexmedetomidine, I max is the maximum possible reduction in MAC iso, and IC 50 is the plasma dexmedetomidine concentration producing 50% of I max. Mean±SE MAC iso.0, determined in a previous study conducted under conditions identical to those in this study, was 2.07±0.04. Weighted mean±SE I max, and IC 50 estimated by the model were 1.76±0.07%, and 1.05±0.08ng/mL, respectively. Dexmedetomidine decreased MAC iso in a concentration-dependent manner. The lowest MAC iso predicted by the model was 0.38±0.08%...

Determinação experimental das distribuições radial e axial de concentração de solidos em uma seção riser utilizando sonda de fibras opticas; Experimental determination of radial and axial solids concentration distributions in a riser section using an optical-fiber probe

Guilherme Jose de Castilho
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/06/2007 PT
Relevância na Pesquisa
36.05%
Regimes gás-sólido têm inúmeras aplicações industriais, sendo empregados, por exemplo, em sistemas de transporte pneumático das partículas e em leito fluidizado. Nas últimas duas décadas notou-se a aplicação crescente do leito fluidizado circulante, principalmente para facilidades de geração de energia, como caldeira e reações catalíticas. No processo de craqueamento catalítico fluidizado (FCC), dentre os vários equipamentos que compõem uma unidade conversora, é no riser onde praticamente ocorrem todas as reações de craqueamento. Medidas de grandezas como concentração de sólidos são fundamentais para a compreensão da fluidodinâmica nestes reatores e é pré-requisito para o projeto técnico bem sucedido de sistemas de transporte pneumático. Dentre as várias técnicas utilizadas para medidas de grandezas básicas em sistemas particulados, a sonda de fibra óptica é relativamente simples, de alta precisão e utilizada em várias situações que envolvem o sistema fluido-partícula. Nesta Dissertação, a oncentração volumétrica dos sólidos é medida por meio de uma sonda de fibra óptica. A concentração volumétrica dos sólidos é tomada radialmente e em diversas posições axiais ao longo do riser sob diferentes condições de operação...

Dependence of Saccharomyces cerevisiae filtration through membrance on yeast concentration

Mota, M.; Teixeira, J. A.; Yelshin, Alexander
Fonte: The American Filtration and Separations Society Publicador: The American Filtration and Separations Society
Tipo: Conferência ou Objeto de Conferência
Publicado em //2004 ENG
Relevância na Pesquisa
36.09%
Filtration of baker’s yeast in an isotonic solution through a 0.45 micron membrane was investigated for yeast concentrations in the range 0.14 – 51 g/L at filtration pressures between 40 and 80 kPa. Yeast filtration through membranes depends on applied filtration pressure and on slurry concentration. It was found that for a yeast volume fraction in suspension above 0.06 the porosity of the yeast cake becomes weakly dependent on the suspension concentration. For highly diluted suspension the specific cake resistance approaches to the minimum value, which is sensitive to the filtration pressure. Correlation functions of the cake porosity and specific cake resistance were obtained in the investigated concentration range. It was found that the Kozeny-Carman coefficient is increased with increasing applied pressure. Both filtration pressure and slurry concentration can be subject of process control. In the range of moderate yeast concentration, manipulation of filtration pressure and of slurry concentration might increase the filtrate flux. Obtained results and assumptions made indicate that complex behavior of yeast cake at high slurry concentration can be further described within the framework of conventional model by increasing complexity of subsystems due to aggregation effect.; Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência...

Bank market concentration and efficiency in the European Union: a panel Granger causality approach

Ferreira, Cândida
Fonte: ISEG. Departamento de Economia - Publicador: ISEG. Departamento de Economia -
Tipo: Outros
Publicado em //2012 ENG
Relevância na Pesquisa
36.05%
The relationships between bank market concentration and bank efficiency are of particular relevance in the European Union (EU), but they remain controversial. Using a panel Granger causality approach, this paper contributes to the literature, testing not only the causality running from bank market concentration to bank efficiency, but also the reverse causality running from efficiency to concentration. The results obtained confirm the relative complexity of these causality relationships, although they generally point to a negative causation running both from concentration to efficiency and from efficiency to concentration. These findings are in line with the Structure Conduct Performance (SCP) paradigm and the suggestions that the increase of the banks’ market power will contribute to inefficiency, since these banks will face less competition to obtain more output results with less input costs. Our results suggest that within this panel of all 27 EU countries over a relatively long time period, from 1996 to the onset of the 2008 financial crisis, the more cost-efficient commercial and savings banks operated in less concentrated markets.

Concentration of pineapple juice by reverse osmosis: physicochemical characteristics and consumer acceptance

Couto,Daniel Simões; Cabral,Lourdes Maria Corrêa; Matta,Virgínia Martins da; Deliza,Rosires; Freitas,Daniela de Grandi Castro
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
Relevância na Pesquisa
36.05%
Reverse osmosis has been used for the concentration of fruit juices with promising considering the quality of the obtained products. The objective of this study was to concentrate single strength pineapple juice by reverse osmosis. The concentration was carried out with polyamide composite membranes in a 0.65 m² plate and frame module at 60 bar transmembrane pressure at 20 °C. The permeate flux was 17 L.hm-2. The total soluble solid content of the juice increased from 11 to 31 °Brix corresponding to a Volumetric Concentration Factor (VCF) of 2.9. The concentration of soluble solids, total solids, and total acidity increased proportionally to FCV. The concentrated juice and three commercial concentrated pineapple juices were evaluated regarding preference and purchase intention by 79 pineapple juice consumers. The concentrated juice by reverse osmosis was the preferred among consumers. It can be concluded that this process may be considered an alternative to the pre-concentration of fruit juices.

Openness, Industrialization, and Geographic Concentration of Activities in China

Catin, Maurice; Luo, Xubei; Van Huffel, Christophe
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
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Rapid development, a widening regional gap, and growing concentration of activities have characterized the Chinese economy since the reforms in the late 1970s. This paper examines the spatial disparities of the economic concentration in different stages of development from a geographic approach in the case of China. It aims at offering empirical supports on (1) how concentrated the economic activities are; (2) what factors determine the economic concentration; and (3) whether this concentration differs in the coastal and inland regions. The results show that the high-technology industries highly concentrate in the coastal provinces. The limited diffusion of the labor intensive activities within the coastal region does not significantly modify the major trend of the location and specialization of the industries in the inland region, and does not contribute to narrowing the regional disparities. The paper argues that in order to stimulate the geographic diffusion of economic activities to the inland region, it is important to appropriately alleviate internal migration control, reduce unnecessary state intervention, and further encourage domestic market integration.

How Urban Concentration Affects Economic Growth

Henderson, Vernon
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
36.13%
The author explores the issue of urban over-concentration econometrically, using data from a panel of 80 to 100 countries every 5 years from 1960 to 1995. He finds the following: 1) At any level of development there is indeed a best degree or national urban concentration. It increases sharply as income rises, up to a per capita income of about $ 5,000 (Penn World table purchasing parity income), before declining modestly. The best degree of concentration declines with country scale. Growth losses from significantly non-optimal concentration are large. Those losses tend to rise with level of development, peaking at a very high level (about 1.5 annual percentage points of economic growth). Results are very robust. 2) In a group of 72 countries in 1990, roughly 30 have satisfactory urban concentration, 24 have excessive concentration, and 5 to 16 countries have too little. 3) The list of countries with highly excessive concentration includes Argentina, Chile, Costa Rica, and Panama (in Latin America); the Republic of Korea and Thailand (in Asia); Congo (in Africa); and Greece...

Grocery market concentration and food price- a case of Australia in comparison with other OECD countries

Kuswini, Mira
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Relatório
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36.14%
This report provides an examination of the level grocery market concentration, food price, and correlation between grocery market concentration ratio and food price level in Australia and a number of other OECD countries. Methods of analysis uses in this report include time-series and cross-national comparison of market concentration ratio and the level of food price. Furthermore, correlation analysis between market concentration ratio and food price level is applied to understand an approximate pattern of the relationship between market concentration and food price. All data and calculations can be found in the report and in the appendices. Results of data analysed show that the level of market concentration is varied among countries under study but most of those countries experienced increase in market concentration in different paces. Average food inflation rate also vary among those countries, and an increase in food price did not always associated with an increase in the level of food price for all countries. However, the level of market concentration positively correlated with food price level in the majority of countries. The report finds that Australia, in comparison with other OECD countries under study has the highest grocery market concentration ratio and the highest average food inflation rate. In addition...

Higher concentration local anaesthetics causing prolonged anaesthesia. Do they? A literature review and case reports

Kingon, A.; Sambrook, P.; Goss, A.
Fonte: Australian Dental Assn Inc Publicador: Australian Dental Assn Inc
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
Relevância na Pesquisa
36.07%
Higher concentration dental local anaesthetics (3% and 4%) have become more available in Australia in recent years. Benefits claimed include a faster onset of anaesthesia and improved success with injections compared to 2% solutions. Recent reports suggest that the higher concentration carries a greater risk of prolonged anaesthesia to the mandibular and particularly the lingual nerves. The literature was reviewed and those studies which demonstrated adverse effects of different concentrations of local anaesthetics were analysed. Recent cases are presented. There is an extensive international literature which confirms increased concentration of local anaesthetic does show an increased risk, by about •6, of prolonged anaesthesia. Five case reports illustrate the impact of this complication on patients’ quality of life. Careful consideration needs to be given before using higher concentration local anaesthetic agents for mandibular and lingual blocks as lower concentration local anaesthetics are safer. If acceptable to individual patients, avoidance of block injections or any local anaesthetic for minor restorative tasks could be encouraged given the severity of the complication. It is safe to use the higher concentration agents for infiltrations away from major nerves.; A Kingon...

Emily Hobhouse und die Berichte über die Konzentrationslager während des Burenkriegs. Zwei unterschiedliche Perspektiven.; Emily Hobhouse and the Reports on the Concentration Camps during the Boer War. Two different perspectives.

Seibold, Birgit Susanne
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
36.09%
Die vorliegende Arbeit verfolgt zwei Ziele. Zum einen stellt sie Biographisches über Emily Hobhouse im Zeitraum von 1899 bis 1902 während des Burenkriegs in Südafrika dar. Dies dient der Charakterisierung einer in Europa gänzlich in Vergessenheit geratenen Person, die doch Wesentliches und Nennenswertes in ihrem Leben geleistet hat. So besuchte Emily Hobhouse als erste britische Zivilistin sechs Konzentrationslager in Südafrika und berichtete von den Zuständen in diesen Lagern. Eine detaillierte Schilderung veröffentlichte sie als Report of a Visit to the Camps of Women and Children in the Cape and Orange River Colonies bei Friars in London (Hobhouse Report). Der Bericht löste eine Schockwelle in England aus und teilte die britische Bevölkerung in Befürworter und Gegner des Konzentrationslagersystems. Das andere Ziel dieser Arbeit ist die Überprüfung der Hypothese, dass sich der Hobhouse Report und der Fawcett Report wesentlich voneinander unterscheiden, da Emily Hobhouse als unabhängig zu erachten ist, wohingegen die Fawcett Commission von der britischen Regierung beauftragt wurde und daher zu folgern ist, dass sie die Zustände in den Lagern beschönigen wird. Hobhouse Report und Fawcett Report sind beide Berichte über die Zustände in den Konzentrationslagern während des Burenkriegs von 1899-1902. Vier Monate lagen zwischen dem Besuch von Emily Hobhouse in den Konzentrationslagern und dem der Ladies’ Commission. Der Fawcett Report war ein nahezu präziser...

Coliform concentration reduction and related performance evaluation of a down-flow anaerobic fixed bed reactor treating low-strength saline wastewater

Rovirosa, Nobel; Sanchez, Enrique; Cruz, Mario; Borja, Rafael; Veiga, María C.
Fonte: Elsevier Sciencie lted Publicador: Elsevier Sciencie lted
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.07%
Low-strength saline wastewater may be generated by tourist facilities, industries and communities located in coastal areas. Sea salts, mostly chlorides, when present in wastewaters at high concentrations, can cause inhibition on biological treatment processes. In this study, a laboratory down-flow anaerobic fixed bed reactor (DFAFBR) was used for treating saline wastewater. This wastewater was simulated by dilution of piggery manure in a synthetic saline water to obtain a final total COD concentration in the range of 1100–2900 mg/l and a salt concentration of 15 g/l. The DFAFBR was operated at hydraulic retention times (HRT) of 96, 48, 24 and 12 h. The results showed that at sea salts concentrations in the range from 5 to 15 g/l, total coliform concentration reduction efficiencies higher than 97% were achieved. A decrease in the total and faecal coliform concentration reduction efficiencies from 99.5% to 90.5% and 92.5%, respectively, was observed when the HRT decreased from 96 to 12 h. Enumeration of coliform bacteria isolated from the biofilm in different zones of the reactor showed that more than 94% of the total amount was removed in the upper zone. A HRT of 24 h was required to obtain total COD, organic-N, total-P and faecal coliform concentration reduction efficiencies higher than 72%...

Estudo da concentração de sedimentos em suspensão no reservatório de Mogi-Guaçu (SP); Study of suspended sediment concentration in Mogi-Guaçu (SP) reservoir

Santos, Bruno Bernardo dos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 21/07/2015 PT
Relevância na Pesquisa
36.05%
Os processos hidrossedimentológicos são complexos e dependem de diversos fatores. Entendê-los requer alto grau de especialização de mão de obra, além da utilização de equipamentos e técnicas ainda incipientes no país. O monitoramento hidrossedimentológico com dados confiáveis de concentração de sedimentos em suspensão pode ser problemático quando são empregados métodos convencionais, pois geralmente os mesmos apresentam medições com quantidade de postos e frequências inferiores aos desejáveis, limitando estudos e a gestão de recursos hídricos quando se trata de reservatórios. Nesse contexto, esta dissertação apresenta um estudo realizado no reservatório da Pequena Central Hidrelétrica Mogi-Guaçu (SP) na qual realizou-se a correlação dos dados de concentração de sedimentos em suspensão mensuradas com dispositivo automático (LISST-100X) e por amostragem convencional (Garrafa Van Dorn). Por meio de regressões lineares e testes estatísticos avaliou-se a eficiência da técnica de difração à laser, e se estimaram as concentrações de sedimentos em suspensão para as duas campanhas realizadas. Analisando os resultados obtidos, confirmou-se estatisticamente que dentre todos os cenários de regressões lineares adotados...

Diurnal effects on mentha canadensis oil concentration and composition at two different harvests

Shiwakoti, Santosh; Sintim, Henry Y.; Poudyal, Shital; Bufalo, Jennifer; Cantrell, Charles L.; Astatkie, Tess; Jeliazkova, Ekaterina; Ciampa, Lyn; Zheljazkov, Valtcho D.
Fonte: Amer Soc Horticultural Science Publicador: Amer Soc Horticultural Science
Tipo: Artigo de Revista Científica Formato: 85-89
ENG
Relevância na Pesquisa
36.1%
Japanese cornmint, also known as menthol mint (Mentiza canadensis L. syn M. arvensis L.), is an essential oil crop cultivated in several countries in Asia and South America. The plant is currently the only commercially viable source for natural menthol as a result of the high concentration of menthol in the oil compared with other crops. The hypothesis of this study was that harvesting at regular intervals within a 24-hour period would have an effect on essential oil concentration and composition of Japanese cornmint grown at high altitude in northern Wyoming. Flowering plants were harvested every 2 hours on 7 to 8 Aug. and on 14 to 15 Aug. and the essential oil was extracted by steam distillation and analyzed by gas chromatography mass spectroscopy (GC-MS). The effects of harvest date (Harvest 1 and Harvest 2) and harvest time (12 times within a 24-hour period) were significant on oil concentration and yield of menthol, but only harvest date was significant on the concentration of menthol in the oil. The interaction effect of harvest date and harvest time was significant on water content and on the concentrations of menthol and menthofuran in the oil and on the yield of limonene, menthol, and menthofuran. Overall, the oil concentration in grams per 100 g dried material for the two harvests (1.26 and 1.45...

Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound

Takeda,Alexandre; Ferraro,Leonardo Henrique Cunha; Rezende,André Hosoi; Sadatsune,Eduardo Jun; Falcão,Luiz Fernando dos Reis; Tardelli,Maria Angela
Fonte: Sociedade Brasileira de Anestesiologia Publicador: Sociedade Brasileira de Anestesiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
Relevância na Pesquisa
36.07%
INTRODUCTION: The use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90) of bupivacaine for axillary brachial plexus block. METHODS: Patients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5 mL for each nerve (radial, ulnar, median, and musculocutaneous). The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block; a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability) or the same concentration (0.9 probability). Surgical anesthesia was defined as driving force ≤2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4 h after the blockade. RESULTS: MEC90 was 0.241% [R 2: 0.978, confidence interval: 0.20-0.34%]. No patient, with successful block, reported pain after 4 h. CONCLUSION: This study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics...

Warrants, ownership concentration, and market liquidity

Brockman, P.; Olsen, B.
Fonte: Emerald Group Publishing Publicador: Emerald Group Publishing
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
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Purpose – Firms issuing equity securities for capital must recognize that this issuance may alter the ownership concentration of the firm. Through this change in ownership structure, the market liquidity of the firm's stock may also change, which has implications for the cost of equity capital and firm value. This paper aims to examine a specific security, the common stock purchase warrant, within this context. It also aims to posit that the decision to issue warrants has important implications for the firm's subsequent ownership structure and market liquidity. Design/methodology/approach – The paper's unique dataset of warrant‐issuing firms tracks the warrants from their issue through to their exercise. Based on the study of SEOs by Kothare, the ownership concentration and market liquidity of the underlying stock prior to and following warrant exercises are measured. The paper examines the causal relations between warrant exercises and ownership changes, and between ownership changes and market liquidity. Findings – The paper shows that firms experience a statistically and economically significant decrease in ownership concentration following warrant exercises. Examining the liquidity effects of this change in ownership, it shows that market liquidity increases significantly after the exercise of warrants...

The impact of immigrants’ segregation and concentration on social integration in selected European contexts

Musterd, Sako
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2011 ENG
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In large sections of the western world there are lively public and policy debates about segregation and integration and in particular about the potential impact of specific population compositions in certain neighbourhoods in cities on integration and social opportunities. There clearly are some prevailing ideologies, perceptions, assumptions and policy responses regarding segregation and potential (neighbourhood) integration effects. In this contribution these prevailing ideas will be addressed and subsequently confronted with theory on segregation, concentration, and neighbourhood effects, and finally confronted with empirical research and evidence. What we learned is that segregation and concentration are no straightforward concepts and thus require cautious treatment. This may help to reduce xenophobic reactions. There are indications, though, that even in so-called redistributing welfare states some (negative) impacts of immigrant concentrations on individual’s prospects can be discerned. However, here too, careful analyses are required to be able to clarify when, for whom, what effects will likely have to be expected.; En el món occidental, l’impacte de certes composicions de la població en determinats barris d’algunes ciutats...

Modelling endogenous insulin concentration in type 2 diabetes during closed loop insulin delivery

Ruan, Yue; Thabit, Hood; Wilinska, Malgorzata E.; Hovorka, Roman
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Article; published version
EN
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This is the final published version. It first appeared at http://www.biomedical-engineering-online.com/content/14/1/19.; Background: Closed-loop insulin delivery is an emerging treatment for type 1 diabetes (T1D) evaluated clinically and using computer simulations during pre-clinical testing. Efforts to make closed-loop systems available to people with type 2 diabetes (T2D) calls for the development of a new type of simulators to accommodate differences between T1D and T2D. Presented here is the development of a model of posthepatic endogenous insulin concentration, a component omitted in T1D simulators but key for simulating T2D physiology. Methods: We evaluated six competing models to describe the time course of endogenous insulin concentration as a function of the plasma glucose concentration and time. The models were fitted to data collected in insulin-naive subjects with T2D who underwent two 24-h visits and were treated, in a random order, by either closed-loop insulin delivery or glucose-lowering oral agents. The model parameters were estimated using a Bayesian approach, as implemented in the WinBUGS software. Model selection criteria were used to identify the best model describing our clinical data. Results: The selected model successfully described endogenous insulin concentration over 24 h in both study periods and provided plausible parameter estimates. Model-derived results were in concordance with a clinical finding which revealed increased posthepatic endogenous insulin concentration during the control study period (P < 0.05). The modelling results indicated that the excess amount of insulin can be attributed to the glucose-independent effect as the glucose-dependent effect was similar between visits (P > 0.05). Conclusions: A model to describe endogenous insulin concentration in T2D including components of posthepatic glucose-dependent and glucose-independent insulin secretion was identified and validated. The model is suitable to be incorporated in a simulation environment for evaluating closed-loop insulin delivery in T2D.; This work was funded in part by a National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre Grant...

Modelling endogenous insulin concentration in type 2 diabetes during closed-loop insulin delivery

Ruan, Yue; Thabit, Hood; Wilinska, Malgorzata E.; Hovorka, Roman
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Article; published version
EN
Relevância na Pesquisa
36.07%
This is the final version of the article. It first appeared at http://www.biomedical-engineering-online.com/content/14/1/19; Background Closed-loop insulin delivery is an emerging treatment for type 1 diabetes (T1D) evaluated clinically and using computer simulations during pre-clinical testing. Efforts to make closed-loop systems available to people with type 2 diabetes (T2D) calls for the development of a new type of simulators to accommodate differences between T1D and T2D. Presented here is the development of a model of posthepatic endogenous insulin concentration, a component omitted in T1D simulators but key for simulating T2D physiology. Methods We evaluated six competing models to describe the time course of endogenous insulin concentration as a function of the plasma glucose concentration and time. The models were fitted to data collected in insulin-naive subjects with T2D who underwent two 24-h visits and were treated, in a random order, by either closed-loop insulin delivery or glucose-lowering oral agents. The model parameters were estimated using a Bayesian approach, as implemented in the WinBUGS software. Model selection criteria were used to identify the best model describing our clinical data. Results The selected model successfully described endogenous insulin concentration over 24 h in both study periods and provided plausible parameter estimates. Model-derived results were in concordance with a clinical finding which revealed increased posthepatic endogenous insulin concentration during the control study period (P??0.05). Conclusions A model to describe endogenous insulin concentration in T2D including components of posthepatic glucose-dependent and glucose-independent insulin secretion was identified and validated. The model is suitable to be incorporated in a simulation environment for evaluating closed-loop insulin delivery in T2D.; This work was funded in part by a National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre Grant...

Concentração de auditoria no mercado de capitais brasileiro; Audit concentration in the Brazilian capital market

Dantas, José Alves; Chaves, Simone de Mesquita Teixeira; Sousa, Gersonete de Araujo; da Silva, Eduardo Monteiro
Fonte: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade de RP Publicador: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade de RP
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; ; ; Formato: application/pdf
Publicado em 01/04/2012 POR
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36.07%
O estudo teve por objetivo avaliar o grau de concentração dos serviços de auditoria independente no mercado de capitais brasileiro entre 2000 e 2009 e levantar aspectos positivos e negativos associados a essa concentração. Os testes empíricos tiveram por base o número de clientes em carteira, os ativos totais e as receitas líquidas das empresas listadas na Bovespa. Tendo como benchmark os parâmetros das autoridades antitrustes brasileiras, não foram encontradas evidências de que a concentração do mercado de auditoria no Brasil viabiliza o exercício coordenado de poder de mercado. Utilizando os critérios das autoridades antitrustes dos EUA, constatou-se que o mercado de auditoria no Brasil é concentrado, com resultados mistos quanto ao nível dessa concentração. Quanto aos impactos da concentração, prevalece na literatura a dualidade relacionada às hipóteses estrutura-conduta-performance (HEP) e estrutura eficiente (HEE). A primeira pressupõe que uma indústria mais concentrada se comportará oportunisticamente, enquanto a segunda prevê que a concentração é decorrência da eliminação de instituições menos eficientes pelas mais eficientes.; This paper is aimed at evaluating the degree of independent audit services concentration in the Brazilian capital market between 2000 and 2009...