910 resultados para indirect and composite estimators
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BACKGROUND AND AIMS: Sustained adipose activation of the transcriptional activators cAMP response binding proteins (CREB) in obesity leads to impaired expression of the glucose transporter GLUT4 and adiponectin (adipoq) in mice model of obesity. Diminution of GLUT4 and adipoq caused by CREB is indirect and relies on the increased repressive activity of the CREB target gene activating transcription factor 3 (ATF3). Specific inactivation of CREB in adipocytes decreases ATF3 production and improves whole-body insulin sensitivity of mice in the context of diet-induced obesity. Thus, elevation of CREB activity is a key mechanism responsible for adipocyte dysfunction and systemic insulin resistance. The inducible cAMP early repressor (ICER) is a negative regulator of the CREB activity. In fact, ICER antagonizes the CREB factor by competing for the regulation of similar target genes. The goal of the study was to investigate whether loss of ICER expression in adipocytes could be responsible for increased CREB activity in obesity. MATERIALS AND METHODS: Mice C57bl6 were fed with a high fat diet (HFD) for 12 weeks to increase body weight and generate insulin resistance. Biopsies of visceral adipose tissues (VAT) were prepared from human lean (BMI=24}0.5 Kg/m2) or obese subjects (BMI>35 Kg/m2). Total RNA and protein were prepared from white adipose tissues (WAT) of chow- or HFD-fed mice and VAT of lean and obese subjects. Activities of CREBs and ICER were monitored by electromobility shift assays (EMSA). The role of ICER on CREB activity was confirmed in 3T3-L1 adipocytes cells. Briefly after differentiation, the cells were electroporated with the plasmid coding for ICER cDNA. Gene expression was quantified by quantitative real-time PCR and western Blotting experiments. RESULTS: The expression of ICER is reduced in WAT of HFD-induced obese mice when compared to chow mice as measured by real-time PCR and EMSA. Similar result was found in human tissues. Reduction in ICER expression was associated with increased ATF3 expression and decreased adipoq and GLUT4 contents. Diminution in ICER levels was observed in adipocytes fraction whereas its expression was unchanged in stroma vascular fraction of WAT. Overexpression of ICER in 3T3-L1 adipocytes silenced the expression of ATF3, confirming the regulation of the factor by ICER. The expression of ICER is regulated by histone deacetylases activity (HDAC). Inhibition of HDACs in 3T3-L1 adipocytes cells using trichostatin inhibited the production of ICER. The whole activity of HDAC was reduced in WAT and VAT of obese mice and human obese subjects. CONCLUSION: Impaired adipose expression of ICER is responsible of increased CREB activity in adipocytes in obesity. This mechanism relies on reduction of the HDAC activity.
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L'exposition aux poussières de bois est associé à un risque accru d'adénocarcinomes des fosses nasales et des sinus paranasaux (SNC, 'Sinonasal cancer') chez les travailleurs du bois. Les poussières de bois sont ainsi reconnues comme cancérogènes avérés pour l'homme par le Centre international de Recherche sur le Cancer (CIRC). Toutefois, l'agent causal spécifique et le mécanisme sous-jacent relatifs au cancer lié aux poussières de bois demeurent inconnus. Une possible explication est une co-exposition aux poussières de bois et aux Hydrocarbures Aromatiques Polycycliques (HAP), ces derniers étant potentiellement cancérogènes. Dans les faits, les travailleurs du bois sont non seulement exposés aux poussières de bois naturel, mais également à celles générées lors d'opérations effectuées à l'aide de machines (ponceuses, scies électriques, etc.) sur des finitions de bois (bois traités) ou sur des bois composites, tels que le mélaminé et les panneaux de fibres à densité moyenne (MDF, 'Medium Density Fiberboard'). Des HAP peuvent en effet être générés par la chaleur produite par l'utilisation de ces machines sur la surface du bois. Les principaux objectifs de cette thèse sont les suivants: (1) quantifier HAP qui sont présents dans les poussières générées lors de diverses opérations courantes effectuées sur différents bois (2) quantifier l'exposition individuelle aux poussières de bois et aux HAP chez les travailleurs, et (3) évaluer les effets génotoxiques (dommages au niveau de l'ADN et des chromosomes) due à l'exposition aux poussières de bois et aux HAP. Cette thèse est composée par une étude en laboratoire (objectif 1) et par une étude de terrain (objectifs 2 et 3). Pour l'étude en laboratoire, nous avons collecté des poussières de différents type de bois (sapin, MDF, hêtre, sipo, chêne, bois mélaminé) générées au cours de différentes opérations (comme le ponçage et le sciage), et ceci dans une chambre expérimentale et dans des conditions contrôlées. Ensuite, pour l'étude de terrain, nous avons suivi, dans le cadre de leur activité professionnelle, 31 travailleurs de sexe masculin (travailleurs du bois et ébenistes) exposés aux poussières de bois pendant deux jours de travail consécutifs. Nous avons également recruté, comme groupe de contrôle, 19 travailleurs non exposés. Pour effectuer une biosurveillance, nous avons collecté des échantillons de sang et des échantillons de cellules nasales et buccales pour chacun des participants. Ces derniers ont également rempli un questionnaire comprenant des données démographiques, ainsi que sur leur style de vie et sur leur exposition professionnelle. Pour les travailleurs du bois, un échantillonnage individuel de poussière a été effectué sur chaque sujet à l'aide d'une cassette fermée, puis nous avons évalué leur exposition à la poussière de bois et aux HAP, respectivement par mesure gravimétrique et par Chromatographie en phase gazeuse combinée à la spectrométrie de masse. L'évaluation des dommages induits à l'ADN et aux chromosomes (génotoxicité) a été, elle, effectuée à l'aide du test des micronoyaux (MN) sur les cellules nasales et buccales et à l'aide du test des comètes sur les échantillons de sang. Nos résultats montrent dans la poussière de la totalité des 6 types de bois étudiés la présence de HAP (dont certains sont cancérogènes). Des différences notoires dans les concentrations ont été néanmoins constatées en fonction du matériau étudié : les concentrations allant de 0,24 ppm pour la poussière de MDF à 7.95 ppm pour le mélaminé. Nos résultats montrent également que les travailleurs ont été exposés individuellement à de faibles concentrations de HAP (de 37,5 à 119,8 ng m-3) durant les opérations de travail du bois, alors que les concentrations de poussières inhalables étaient relativement élevés (moyenne géométrique de 2,8 mg m-3). En ce qui concerne la génotoxicité, les travailleurs exposés à la poussière de bois présentent une fréquence significativement plus élevée en MN dans les cellules nasales et buccales que les travailleurs du groupe témoin : un odds ratio de 3.1 a été obtenu pour les cellules nasales (IC 95% : de 1.8 à 5.1) et un odds ratio de 1,8 pour les cellules buccales (IC 95% : de 1.3 à 2.4). En outre, le test des comètes a montré que les travailleurs qui ont déclaré être exposés aux poussières de MDF et/ou de mélaminé avaient des dommages à l'ADN significativement plus élevés que les deux travailleurs exposés à la poussière de bois naturel (sapin, épicéa, hêtre, chêne) et que les travailleurs du groupe témoin (p <.01). Enfin, la fréquence des MN dans les cellules nasales et buccales augmentent avec les années d'exposition aux poussières de bois. Par contre, il n'y a pas de relation dose-réponse concernant la génotoxicité due à l'exposition journalière à la poussière et aux HAP. Cette étude montre qu'une exposition aux HAP eu bien lieu lors des opérations de travail du bois. Les travailleurs exposés aux poussières de bois, et donc aux HAP, courent un risque plus élevé (génotoxicité) par rapport au groupe témoin. Étant donné que certains des HAP détectés sont reconnus potentiellement cancérogènes, il est envisageable que les HAP générés au cours du travail sur les matériaux de bois sont un des agents responsables de la génotoxicité de la poussière de bois et du risque élevé de SNC observé chez les travailleurs du secteur. Etant donné la corrélation entre augmentation de la fréquence des MN, le test des micronoyaux dans les cellules nasales et buccales constitue sans conteste un futur outil pour la biosurveillance et pour la détection précoce du risque de SNC chez les travailleurs. - Exposures to wood dust have been associated with an elevated risk of adenocarcinomas of the Dasal cavity and the paranasal sinuses (sinonasal cancer or SNC) among wood workers. Wood dust is recognized as a human carcinogen by the International Agency for Research on Cancer. However, the specific cancer causative agent(s) and the mechanism(s) behind wood dust related carcinogenesis remains unknown. One possible explanation is a co-exposure to wood dust and polycyclic aromatic hydrocarbons (PAH), the latter being carcinogenic. In addition, wood workers are not only exposed to natural wood but also to wood finishes and composite woods such as wood melamine and medium density fiber (MDF) boards during the manipulation with power tools. The heat produced by the use of power tools can cause the generation of PAH from wood materials. The main objectives of the present thesis are to: (1) quantify possible PAH concentrations in wood dust generated during various common woodworking operations using different wood materials; (2) quantify personal wood dust concentrations and PAH exposures among wood workers; and (3) assess genotoxic effects (i.e., DNA and chromosomal damage) of wood dust and PAH exposure in wood workers. This thesis is composed by a laboratory study (objective 1) and a field study (objectives 2 and 3). In the laboratory study we collected wood dust from different wood materials (fir, MDF, beech, mahagany, oak, and wood melamine) generated during different wood operations (e.g., sanding and sawing) in an experimental chamber under controlled conditions. In the following field study, we monitored 31 male wood workers (furniture and construction workers) exposed to wood dust during their professional activity for two consecutive work shifts. Additionally, we recruited 19 non exposed workers as a control group. We collected from each participant blood samples, and nasal and buccal cell samples. They answered a questionnaire including demographic and life-style data and occupational exposure (current and past). Personal wood dust samples were collected using a closed-face cassette. We used gravimetrie analysis to determine the personal wood dust concentrations and capillary gas chromatography - mass spectrometry analysis to determine PAH concentrations. Genotoxicity was assessed with the micronucleus (MN) assay for nasal and buccal cells and with the comet assay for blood samples. Our results show that PAH (some of them carcinogenic) were present in dust from all six wood materials tested, yet at different concentrations depending on the material. The highest concentration was found in dust from wood melamine (7.95 ppm) and the lowest in MDF (0.24 ppm). Our results also show that workers were individually exposed to low concentrations of PAHs (37.5-119.8 ng m"3) during wood working operations, whereas the concentrations of inhalable dust were relatively high (geometric mean 2.8 mg m"3). Concerning the genotoxicity, wood workers had a significantly higher MN frequency in nasal and buccal cells than the workers in the control group (odds ratio for nasal cells 3.1 (95%CI 1.8-5.1) and buccal cells 1.8 (95%CI 1.3-2.4)). Furthermore, the comet assay showed that workers who reported to be exposed to dust from wooden boards (MDF and wood melamine) had significantly higher DNA damage than both the workers exposed to natural woods (fir, spruce, beech, oak) and the workers in the control group (p < 0.01). Finally, MN frequency in nasal and buccal cells increased with increasing years of exposure to wood dust. However, there was no genotoxic dose-response relationship with the per present day wood dust and PAH exposure. This study shows that PAH exposure occurred during wood working operations. Workers exposed to wood dust, and thus to PAH, had a higher risk for genotoxicity compared to the control group. Since some of the detected PAH are potentially carcinogenic, PAH generated from operations on wood materials may be one of the causative agents for the observed increased genotoxicity in wood workers. Since increased genotoxicity is manifested in an increased MN frequency, the MN assay in nasal and buccal cells may become a relevant biomonitoring tool in the future for early detection of SNC risk.
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INTRODUCTION: A significant proportion of prematurely born children encounter behavioral difficulties, such as attention deficit or hyperactivity, which could be due to executive function disorders. AIMS: To examine whether the standard neurodevelopmental assessment offered to premature children in Switzerland recognizes executive function disorders. METHODS: The study population consisted of 49 children born before 29 weeks of gestation who were examined between 5 and 6 years of age with a standard assessment, with additional items to assess executive functioning. Children with severe neurodevelopmental impairment were excluded (mental retardation, cerebral palsy, autism). Standard assessment consisted in the Kaufman Assessment Battery for Children (K-ABC), which comprises three subscales: sequential processes (analysis of sequential information), simultaneous processes (global analysis of visual information), and composite mental processes (CMP) (result of the other two scales), as well as a behavioral evaluation using the standardized Strengths and Difficulties Questionnaire (SDQ). Executive functioning was assessed with tasks evaluating visual attention, divided attention, and digit memory as well as with a specialized questionnaire, the Behavior Rating Index of Executive Functions (BRIEF), which evaluates several aspects of executive function (regulation, attention, flexibility, working memory, etc). RESULTS: Children were divided according to their results on the three K-ABC scales (< or>85), and the different neuropsychological tasks assessing executive function were compared between the groups. The CMP did not differentiate children with executive difficulties, whereas a score<85 on the sequential processes was significantly associated with worse visual and divided attention. There was a strong correlation between the SDQ and the BRIEF questionnaires. For both questionnaires, children receiving psychotherapy had significantly higher results. Children who presented behavioral problems assessed with the SDQ presented significantly higher scores on the BRIEF. CONCLUSION: A detailed analysis of the standard neurodevelopmental assessment allows the identification of executive function disorders in premature children. Children who performed below 85 on the sequential processes of the K-ABC had significantly more attentional difficulties on the neuropsychological tasks and therefore have to be recognized and carefully followed. Emotional regulation had a strong correlation with behavioral difficulties, which were suitably assessed with the SDQ, recognized by the families, and treated.
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En este articulo se presenta una aplicación de dos de las metodologías desarrolladas para medir los beneficios que se derivan del uso recreativo de los bienes ambientales en ausencia de mercado, el método del coste del viaje (MCV) y el de valoración contingente (MVC). La zona objeto de estudio ha sido el Parque Nacional de "Aigüestortes y Estany de Sant Maunici", situado en el pirineo catalán. El trabajo se ha estructurado de la forma siguiente. Tras una breve introducción, en los apartados Il y III se expone el modelo teórico de ambas metodologías de valoración, se analiza su aplicación y se comentan los principales problemas derivados de su uso. En los apartados IV y V se muestran los resultados obtenidos mediante ambas técnicas de valoración. En el apartado VI se comparan los resultados y se discuten algunos problemas metodológicos derivados de su aplicación haciendo hincapié en la sensibilidad de los mismos alas hipótesis consideradas. Finalmente el trabajo termina con unas reflexiones a modo de conclusión.
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Fibre-reinforced composite (FRC) root canal posts are suggested to have biomechanical benefits over traditional metallic posts, but they lack good adhesion to resin composites. The aim of this series of studies was to evaluate the adhesion of individually formed fibre-reinforced composite material to composite resin and dentin, as well as some mechanical properties. Flexural properties were evaluated and compared between individually formed FRC post material and different prefabricated posts. The depth of polymerization of the individually formed FRC post material was evaluated with IR spectrophotometry and microhardness measurements, and compared to that of resin without fibres. Bonding properties of the individually formed FRC post to resin cements and dentin were tested using Pull-out- and Push-out-force tests, evaluated with scanning electron microscopy, and compared to those of prefabricated FRC and metal posts. Load-bearing capacity and microstrain were evaluated and failure mode assessment was made on incisors restored with individually formed FRC posts of different structures and prefabricated posts. The results of these studies show that the individually polymerized and formed FRC post material had higher flexural properties compared to the commercial prefabricated FRC posts. The individually polymerized FRC material showed almost the same degree of conversion after light polymerization as monomer resin without fibres. Moreover, it was found that the individually formed FRC post material with a semiinterpenetrating polymer network (IPN) polymer matrix bonded better to composite resin luting cement, than did the prefabricated posts with a cross-linked polymer matrix. Furthermore, it was found that, contrary to the other posts, there were no adhesive failures between the individually formed FRC posts and composite resin luting cement. This suggests better interfacial adhesion of cements to these posts. Although no differences in load-bearing capacity or microstrain could be seen, the incisors restored with individually formed FRC posts with a hollow structure showed more favourable failures compared to other prefabricated posts. These studies suggest that it is possible to use individually formed FRC material with semi-IPN polymer matrix as root canal post material. They also indicate that there are benefits especially regarding the bonding properties to composite resin and dentin with this material compared to prefabricated FRC post material with a cross-linked matrix. Furthermore, clinically more repairable failures were found with this material compared to those of prefabricated posts.
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The variability observed in drug exposure has a direct impact on the overall response to drug. The largest part of variability between dose and drug response resides in the pharmacokinetic phase, i.e. in the dose-concentration relationship. Among possibilities offered to clinicians, Therapeutic Drug Monitoring (TDM; Monitoring of drug concentration measurements) is one of the useful tool to guide pharmacotherapy. TDM aims at optimizing treatments by individualizing dosage regimens based on blood drug concentration measurement. Bayesian calculations, relying on population pharmacokinetic approach, currently represent the gold standard TDM strategy. However, it requires expertise and computational assistance, thus limiting its large implementation in routine patient care. The overall objective of this thesis was to implement robust tools to provide Bayesian TDM to clinician in modern routine patient care. To that endeavour, aims were (i) to elaborate an efficient and ergonomic computer tool for Bayesian TDM: EzeCHieL (ii) to provide algorithms for drug concentration Bayesian forecasting and software validation, relying on population pharmacokinetics (iii) to address some relevant issues encountered in clinical practice with a focus on neonates and drug adherence. First, the current stage of the existing software was reviewed and allows establishing specifications for the development of EzeCHieL. Then, in close collaboration with software engineers a fully integrated software, EzeCHieL, has been elaborated. EzeCHieL provides population-based predictions and Bayesian forecasting and an easy-to-use interface. It enables to assess the expectedness of an observed concentration in a patient compared to the whole population (via percentiles), to assess the suitability of the predicted concentration relative to the targeted concentration and to provide dosing adjustment. It allows thus a priori and a posteriori Bayesian drug dosing individualization. Implementation of Bayesian methods requires drug disposition characterisation and variability quantification trough population approach. Population pharmacokinetic analyses have been performed and Bayesian estimators have been provided for candidate drugs in population of interest: anti-infectious drugs administered to neonates (gentamicin and imipenem). Developed models were implemented in EzeCHieL and also served as validation tool in comparing EzeCHieL concentration predictions against predictions from the reference software (NONMEM®). Models used need to be adequate and reliable. For instance, extrapolation is not possible from adults or children to neonates. Therefore, this work proposes models for neonates based on the developmental pharmacokinetics concept. Patients' adherence is also an important concern for drug models development and for a successful outcome of the pharmacotherapy. A last study attempts to assess impact of routine patient adherence measurement on models definition and TDM interpretation. In conclusion, our results offer solutions to assist clinicians in interpreting blood drug concentrations and to improve the appropriateness of drug dosing in routine clinical practice.
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BACKGROUND AND PURPOSE: Information about outcomes in Embolic Stroke of Undetermined Source (ESUS) patients is unavailable. This study provides a detailed analysis of outcomes of a large ESUS population. METHODS: Data set was derived from the Athens Stroke Registry. ESUS was defined according to the Cryptogenic Stroke/ESUS International Working Group criteria. End points were mortality, stroke recurrence, functional outcome, and a composite cardiovascular end point comprising recurrent stroke, myocardial infarction, aortic aneurysm rupture, systemic embolism, or sudden cardiac death. We performed Kaplan-Meier analyses to estimate cumulative probabilities of outcomes by stroke type and Cox-regression to investigate whether stroke type was outcome predictor. RESULTS: 2731 patients were followed-up for a mean of 30.5±24.1months. There were 73 (26.5%) deaths, 60 (21.8%) recurrences, and 78 (28.4%) composite cardiovascular end points in the 275 ESUS patients. The cumulative probability of survival in ESUS was 65.6% (95% confidence intervals [CI], 58.9%-72.2%), significantly higher compared with cardioembolic stroke (38.8%, 95% CI, 34.9%-42.7%). The cumulative probability of stroke recurrence in ESUS was 29.0% (95% CI, 22.3%-35.7%), similar to cardioembolic strokes (26.8%, 95% CI, 22.1%-31.5%), but significantly higher compared with all types of noncardioembolic stroke. One hundred seventy-two (62.5%) ESUS patients had favorable functional outcome compared with 280 (32.2%) in cardioembolic and 303 (60.9%) in large-artery atherosclerotic. ESUS patients had similar risk of composite cardiovascular end point as all other stroke types, with the exception of lacunar strokes, which had significantly lower risk (adjusted hazard ratio, 0.70 [95% CI, 0.52-0.94]). CONCLUSIONS: Long-term mortality risk in ESUS is lower compared with cardioembolic strokes, despite similar rates of recurrence and composite cardiovascular end point. Recurrent stroke risk is higher in ESUS than in noncardioembolic strokes.
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International sport governing bodies (ISGBs) are built on the foundations of freedom of association and traditionally enjoy a large degree of autonomy in their decision-making. Their autonomy is increasingly confined, however, and their hierarchical self-governance is giving way to a more networked governance, in which different stakeholders exert power in different ways and in different contexts in a complex web of interrelationships. Taking a rationalist perspective on the autonomy of ISGBs, this article demonstrates that ISGBs are deploying strategies to safeguard their waning governing monopoly over international sport. Opting for an inductive approach, the authors present four possible conceptualizations of autonomy as applied to ISGBs, namely political autonomy, legal autonomy, financial autonomy and pyramidal autonomy. For each dimension, they describe the different strategies ISGBs wield in order to safeguard different dimensions of their autonomy. This article uses governance theories to hypothesize that the autonomy of ISGBs can be understood as 'pragmatic autonomy' since ISGBs only cede certain aspects of their autonomy under particular circumstances and when being subject to specific threats. Acting in a rationalist manner, they are able to keep control over governance developments in sport by using indirect and more subtle forms of governance.
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A discussion about groundwater contamination is presented in this work. Contamination by agricultural activity, more specifically by pesticides is emphasized. Indirect and direct estimates could be used to predict pesticide behavior in soil, and consequently, to evaluate the potential of groundwater contamination. These results could be applied to advise about the possibility of groundwater contamination by pesticides, and to provide subsidies for making decisions more quickly and efficiently.
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The use of lignocellulosic fibers and their constituents, as raw materials in the production of polymeric and composite materials, represent an exceptional opportunity of sustainable technological development. In the present report works that discuss promising alternatives of obtaining and use of materials such as cellulose, hemicellulose, lignin, cellulose nanocrystals and biocomposites were revised. The advance in the use of biomass can be, in a near future, capable of going beyond the application difficulties of these vast materials, especially in relation to the economical unviability, by the production of high performance polymeric and composite materials. This advance would represent a higher profitability to some areas of agrobusiness, especially the sector of biofuels, which produces elevated amounts of biomass waste.
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The potentialities and applications of the Multiple Pulse Amperometric detection (MPA) coupled with Flow Injection Analysis (FIA) are evaluated. Important aspects as cleaning and activation of electrode surface, indirect and simultaneous analysis of electroactive compounds and the use of the internal standard method for quantifications utilizing FIA-MPA are presented. The main parameters concerning the detection of electroactive analytes by multiple pulse amperometric detection in flowing solutions were also discussed. In addition, aspects such as flow rate, sample volume, application time of the potential pulses and instrumentation necessary for implementing of the method were also addressed.
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The main objective of this Master’s thesis is to find out which one of the two pricing models is the most cost-effective. In this thesis there are two companies that have made an outsourcing contract, in which they have a possibility to choose between two different pricing models. The first model is so called FTE (Full Time Employee) -based. The total cost will be based on the amount of outsourced person-workyears. The second pricing model is the transaction-based, in which the price will be formed according to the amount of transactions. Changing the pricing model from FTE-based to the transaction-based will also incur other costs. It is very important that these other costs are also taken into consideration, so that it is possible to determine the total costs of the pricing models. These other costs are direct costs, indirect costs and performance related costs of outsourcing. Activity based-costing (ABC) was used in order to find out the trues indirect costs of the outsourced processes. Performance related costs are related to quality, so Pareto-analysis was used to analyse the costs. Based on all of that, a framework for service related cost analysis was developed. Quality costs were almost impossible to quantify, so quality had to be taken into consideration in a qualitative way. Furthermore, considering only the indirect and direct costs in a quantitative way and quality costs in a qualitative way, it was possible to find a conditional solution for the research question.
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The topic of this thesis is the simulation of a combination of several control and data assimilation methods, meant to be used for controlling the quality of paper in a paper machine. Paper making is a very complex process and the information obtained from the web is sparse. A paper web scanner can only measure a zig zag path on the web. An assimilation method is needed to process estimates for Machine Direction (MD) and Cross Direction (CD) profiles of the web. Quality control is based on these measurements. There is an increasing need for intelligent methods to assist in data assimilation. The target of this thesis is to study how such intelligent assimilation methods are affecting paper web quality. This work is based on a paper web simulator, which has been developed in the TEKES funded MASI NoTes project. The simulator is a valuable tool in comparing different assimilation methods. The thesis contains the comparison of four different assimilation methods. These data assimilation methods are a first order Bayesian model estimator, an ARMA model based on a higher order Bayesian estimator, a Fourier transform based Kalman filter estimator and a simple block estimator. The last one can be considered to be close to current operational methods. From these methods Bayesian, ARMA and Kalman all seem to have advantages over the commercial one. The Kalman and ARMA estimators seems to be best in overall performance.
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Tässä tutkimuksessa tarkastellaan vanhempien havaintoja ja käsityksiä lapsen sosiaalisesta kompetenssista. Lapsen sosiaalisesta kompetenssista tarkastelun kohteena ovat erityisesti vertaissuhteet, sosiaaliset taidot ja sosiaalinen käyttäytyminen. Tarkoituksena on selvittää vanhempien näkemyksiä lapsen sosiaalisesta verkostosta ja lapsesta sosiaalisena toimijana. Kiinnostuksen kohteena on myös, miten vanhemmat vaikuttamaan lapsen sosiaaliseen kompetenssiin. Vanhempien vaikutuksessa voidaan erottaa epäsuora ja suora vaikutus. Vanhempien epäsuoraan vaikutukseen kuuluvat perheen sosioekonomiset tekijät, vanhemmuuteen ja lastenkasvatukseen liittyvät käytännöt sekä lapsen ja vanhemman välinen vuorovaikutus. Suora vaikutus sisältää vanhempien eri roolit ja tehtävät sosiaalisen kompetenssin edistämiseksi. Vanhempien epäsuorilla ja suorilla vaikutustavoilla on havaittu olevan merkittävää vaikutusta lapsen sosiaalisen kompetenssiin muotoutumiseen ja sen laatuun. Tutkimuksessa selvitetään vertaissuhdeongelmaisten ja ei-ongelmaisten lasten vanhempien välisiä eroja näissä vaikutustavoissa. Tutkimuksessa hyödynnetään kyselylomake- ja haastatteluaineistoja. Kyselylomakeaineisto (N=156) kerättiin ”Origins of Exclusion in Early Childhood”-tutkimusprojektissa, jossa tutkittiin lasten vertaissuhteita, sosiaalisia taitoja sekä sosiaalista käyttäytymistä kolmen vuoden seurantatutkimuksena päiväkodista kouluun. Perhekysely toteutettiin lasten ollessa kuusivuotiaita. Vanhempien haastatteluaineisto (N=55) koostuu projektissa mukana olleiden lasten vanhempien teemahaastatteluista. Perhekyselyä analysoidaan tilastollisin analyysimenetelmin. Laadullisen aineiston analyysimenetelmänä käytetään sisällönanalyysia. Vanhempien käsityksissä lasten sosiaalinen verkosto rakentui kotiympäristössä, koulussa, päiväkodissa sekä suvun ja harrastusten parissa muodostuneista suhteista. Tutkimustulosten perusteella on havaittavissa, että vertaissuhdeongelmaisten ja ei-ongelmaisten lasten sosiaaliset verkostot ovat osin erilaiset. Vanhempien arviointien mukaan myös lasten sosiaalisissa taidoissa, käyttäytymisessä, asennoitumisessa sosiaaliseen kanssakäymiseen sekä ryhmään ja leikkeihin liittyvissä strategioissa on eroavaisuuksia. Tutkimuksen pohjalta voidaan todeta, että vanhemmat pystyvät arvioimaan hyvin yksityiskohtaisesti lapsensa sosiaalisia taitoja ja käyttäytymistä. Kaikilla vanhemmilla ei kuitenkaan ollut riittävästi tietoa lasten kaveripiiristä tai sen laadusta eikä lasten sosiaalisesta orientaatiosta. Vanhempien epäsuorissa vaikutustavoissa oli eroja, mutta myös yhtäläisyyksiä. Sosioekonomisia tekijöitä koskevan tarkastelun perusteella vertaissuhdeongelmaisten lasten perheiden taloudelliset ongelmat, isien työttömyys ja lapsen erityisen tuen tarve olivat yhteydessä lapsen sosiaalisten suhteiden ongelmiin. Lähes kaikki tutkimukseen osallistuneet vanhemmat kokivat vanhemmuuden ja kasvatustehtävän kuitenkin hyvin myönteisenä ja tyytyväisyyttä tuottavana asiana elämässä. Valtaosa vanhemmista piti lapsen ja aikuisen välistä vuorovaikutusta positiivisena, vaikka lapsen kanssa ei aina ollutkaan helppoa tulla toimeen. Tyytyväisyydestä huolimatta äidit näkivät itsessään enemmän kehittymisen tarpeita vanhempana kuin isät. Vanhemmuudessa korostuivat ohjaaminen ja kontrolli, mutta myös hoiva, lämpö ja vastavuoroisuus. Hoiva ja lämpö sekä rajojen asettaminen askarruttivat vanhempia suuresti. Vertaissuhdeongelmaisten lasten vanhemmat tarvitsisivat opastusta ohjaavan vanhemmuuden löytämiseksi. Vertaissuhdeongelmaisten lasten vanhemmat kuvasivat kasvatuksen kuormittavuutta, ajan puutetta sekä muuntuvaa isyyttä ja äitiyttä ei-ongelmaisten lasten vanhempia enemmän. Työn ja perheen yhteensovittamisen vaikeus tuli myös esille vanhempien kuvauksissa. Kyvykkään vanhemmuuden kannalta epävirallinen läheisistä muodostunut tukiverkosto on tärkeä vanhemman apu ja kasvatuksen turva. Ensisijaisena tukitahona on epävirallinen verkosto, joka koostuu ystävistä, tuttavista, työtovereista, puolisosta ja omista vanhemmista. Vertaissuhdeongelmaisten lasten vanhempien mukaan arjen tukea ei kuitenkaan ole aina saatavilla, eikä tukiverkosto tyydyttänyt vanhempia. Vanhempien käsityksissä perheen vuorovaikutus sujui hyvin ja vastuu kodista ja kasvatustehtävästä oli molemmilla vanhemmilla tasavertaisesti. Käytännön vastuu kasvatuksesta sekä erilaisten taitojen opettamisesta lapsille kuului äitien tehtäviin. Vanhempien näkemyksissä lapsen sosiaalinen maailma rakentui lähiympäristön tarjoamista mahdollisuuksista. Vanhempien suoriin vaikutustapoihin liittyvien tulosten mukaan vanhemmat pitävät harrastuksia merkittävänä sosiaalista kompetenssia edistävänä tekijänä. Ei-ongelmaisilla lapsilla oli enemmän ja monipuolisempia harrastuksia kuin ongelmaisilla lapsilla. Vaikka vanhemmat eivät mieltäneetkään omaa toimintaansa kaveripiiriin ohjaamiseksi, heillä useinkin oli runsaasti erilaisia rooleja ja tehtäviä sosiaalisten suhteiden ja sosiaalisten taitojen opettamisessa. Lapsen sosiaalisten suhteiden organisoinnissa, ohjaamisessa, valvonnassa ja neuvonnassa oli vanhempiryhmien välillä eroja. Vertaissuhdeongelmaisten lasten vanhemmat eivät olleet riittävän hyvin perillä lapsen taidoista ja kyvykkyydestä tuottaakseen oikea-aikaista ohjausta ja tukeakseen lasta riittävästi sopivilla tavoilla. Vanhempien toimintaa näyttää ohjaavan vakaasti se uskomus, että lapsen kaverisuhteet ovat pelkästään hänen oma asiansa. Vanhemmat arvostivat paljon sosiaalisia taitoja ja pyrkivät opettamaan niitä lapsilleen systemaattisesti. Ohjaamisen tavoissa vanhemmat poikkesivat toisistaan. Tutkimus antaa viitteitä, että eiongelmaisten lasten vanhemmat ovat sensitiivisempiä, vastavuoroisempia ja lapsen näkökulmaa ja tarpeita lähtökohtanaan pitäviä sekä tunnetaitoihin ja tunnetilan käsittelyyn keskittyvämpiä kuin ongelmaisten lasten vanhemmat. Vanhempien ja lasten vuorovaikutuksen vaikeudet, ylimalkainen ja epäjohdonmukainen sosiaalisten taitojen, käyttäytymisen sekä suhteiden ohjaus sekä monet perheen voimavarojen puutteet voivat haitata vakavasti lapsen sosiaalisen kompetenssin kehittymistä. Vanhemmilla on kuitenkin taitoa arvioida lapsensa sosiaalista kyvykkyyttä ja halua toimia hyvin kasvatustehtävässään. Vanhemmuuden tukemisessa olisivatkin tärkeitä epävirallisen tukiverkoston lisäksi lähiympäristön perheille ja lapsille suunnatut palvelut, monitahoinen yhteistyö perheiden, lasten ja heidän kanssaan työskentelevien ammattilaisten kesken sekä yhteiskunnan perheitä koskevat säädökset ja tukitoimet.
Resumo:
OBJECTIVE: To assess liver regeneration in rats after 60% hepatectomy with and without supplementation of L-glutamine through liver weight changes, laboratory parameters and histological study.METHODS: 36 male rats were divided into two groups: glutamine group and control group. Each group was subdivided into three subgroups, with death in 24h, 72h and seven days. The glutamine group received water and standard diet supplemented with L-glutamine, and the control recieved 0.9% saline. In all subgroups analysis of liver regeneration was made by the Kwon formula, study of liver function (AST, ALT, GGT, total bilirubin, indirect and indirect bilirubin and albumin) and analysis of cell mitosis by hematoxylin-eosin.RESULTS: In both groups there was liver regeneration by weight gain. Gamma-GT increased significantly in the control group (p < 0.05); albumin increased in the glutamine group. The other indicators of liver function showed no significant differences. Histological analysis at 72h showed a higher number of mitoses in the glutamine group, with no differences in other subgroups.CONCLUSION: Diet supplementation with L glutamine is beneficial for liver regeneration.