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Variation in treatment : an analysis of dental radiographs using matched patient provider dataElouafkaoui, Paula January 2011 (has links)
Variation in health care, whether it be in terms of the utilisation of resources, observed health outcomes, costs, quality or access to health care is a well recognised and ever present feature of the modern day health care system. Health care variations challenge basic assumptions about the nature of the health care economy and raise questions about efficiency, equity and where best to direct policy instruments in health care markets. Despite the vast literature documenting variation, and the many discussions around ways to reduce variations in health care markets, the field of dental care has received little interest, in comparison to that of general medical care. This thesis will address this gap and will analyse the variation observed in a specific dental care treatment (dental radiographs) within NHS Scotland, with particular emphasis on the contribution of both dentist and patient unobserved heterogeneity. The thesis takes its focus from two strands of the literature; the underlying theoretical aspect draws on the literature concerning the theory of incentives and physician agency, whilst the empirical component makes use of recent advances in micro-econometric methods, documented in the labour economics literature. Although the thesis is predominantly an empirical analysis, the estimation strategy combines ideas from both the theoretical and empirical literature. A matched patient provider dataset from NHS Scotland is used to conduct an analysis of the variation in dental radiographs, in the presence of, and controlling for unobserved dentist and patient heterogeneity. The results indicate that the remuneration structure alone has little or no impact on the treatment decision to provide a radiograph. When a dentist changes from being on a fixed salary contract to being paid on a fee-for-service basis, they are in fact less likely to provide a radiograph. This result changes in the presence of insurance (identified as being when patients are exempt from the patient charge) and indicates that when the self employed dentist can identify the patient as being exempt, they are more likely to provide a radiograph. This result provides some support for the theory that in the presence of insurance, financial incentives do influence the treatment decision. A final result of the study highlights the importance of accounting for unobserved patient and provider heterogeneity, a factor that has had little attention in the healthcare literature. The results suggest that patient variation, as opposed to the variation across dentists, is much more important in explaining total variation. This is a similar result to that found in both the labour and education literatures.
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Effects of anti-osteoporosis drugs on human mast cells.January 2010 (has links)
Lee, Hoi Ying. / "September 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 171-189). / Abstracts in English and Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iii / Acknowledgement --- p.v / Publications --- p.vi / Abbreviations --- p.vii / Table of Content --- p.x / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Human mast cells and its activation --- p.1 / Chapter 1.2 --- Role of mast cells in inflammation --- p.2 / Chapter 1.3 --- Mast cell heterogeneity --- p.5 / Chapter 1.4 --- Interaction of bone and immune system --- p.1 / Chapter 1.5 --- Introduction of bone system --- p.8 / Chapter 1.6 --- Bone remodeling --- p.9 / Chapter 1.7 --- Regulation of bone remodeling --- p.10 / Chapter 1.8 --- Introduction of Osteoporosis --- p.12 / Chapter 1.9 --- Pathophysiology of osteoporosis --- p.13 / Chapter 1.10 --- Pharmacological interventions in osteoporosis --- p.14 / Chapter 1.11 --- Involvement of mast cells in bone metabolism --- p.18 / Chapter 1.12 --- Aim of study --- p.20 / Chapter 2 --- Materials and Methods --- p.27 / Chapter 2.1 --- Materials --- p.27 / Chapter 2.2 --- Methods --- p.34 / Chapter 2.2.1 --- Human mast cells culture --- p.34 / Chapter 2.2.2 --- Human mast cells characterization --- p.35 / Chapter 2.2.3 --- Histamine release assay --- p.36 / Chapter 2.2.4 --- Immunofluorescence staining of estrogen receptors --- p.37 / Chapter 2.2.5 --- Reverse Transcriptase Polymerase Chain Reaction --- p.37 / Chapter 2.2.6 --- TNF measurement --- p.38 / Chapter 2.2.7 --- Calcium mobilization studies of mast cells --- p.38 / Chapter 2.2.8 --- Statistical analysis --- p.39 / Chapter 3 --- Effects of estrogen and selective estrogen receptor modulators (SERMs) on mediators release from human mast cells --- p.41 / Chapter 3.1 --- Introduction --- p.41 / Chapter 3.2 --- Materials and methods --- p.50 / Chapter 3.3 --- Results --- p.51 / Chapter 3.3.1 --- Characterization of human mast cells --- p.51 / Chapter 3.3.2 --- Effect of estrogen on mediator release from human mast cells --- p.52 / Chapter 3.3.2.1 --- Basal histamine release after treatment of estrogen --- p.52 / Chapter 3.3.2.2 --- Histamine release induced by immunological stimulus --- p.52 / Chapter 3.3.2.3 --- Histamine release induced by chemical secretagogues --- p.54 / Chapter 3.3.3 --- Effect of selective estrogen receptor modulators (SERMs) on mast cell activity --- p.54 / Chapter 3.3.3.1 --- Basal histamine release after SERMs treatment --- p.54 / Chapter 3.3.3.2 --- Histamine release induced by immunological stimulus --- p.55 / Chapter 3.3.3.3 --- Histamine release induced by chemical secretagogues --- p.57 / Chapter 3.3.4 --- Effect of estradiol on TNF-α release from human mast cells --- p.57 / Chapter 3.3.5 --- Effect of SERMs on TNE-α release from human mast cells --- p.58 / Chapter 3.3.6 --- Expression of estrogen receptors on human mast cells --- p.59 / Chapter 3.3.6.1 --- Expression of estrogen receptor after treatment of estradiol --- p.59 / Chapter 3.3.7 --- Expression of various bone remodeling molecules on human mast cells --- p.60 / Chapter 3.3.7.1 --- Expression of bone remodeling molecule after treatment of estradiol --- p.61 / Chapter 3.4 --- Discussion --- p.63 / Chapter 4 --- Effects of anti-osteoporosis Chinese herbal medicines on activity of human mast cells --- p.98 / Chapter 4.1 --- Introduction --- p.98 / Chapter 4.2 --- Materials and methods --- p.103 / Chapter 4.3 --- Results --- p.104 / Chapter 4.3.1 --- Effect of the anti-osteoporosis Chinese herbal formulation ELP on histamine release from human mast cells --- p.104 / Chapter 4.3.1.1 --- Histamine release induced by immunological stimulus --- p.104 / Chapter 4.3.1.2 --- Histamine release induced by chemical secretagogues --- p.105 / Chapter 4.3.2 --- Effect of Herba Epimedii (HEP) on histamine release from human mast cells --- p.105 / Chapter 4.3.2.1 --- Histamine release induced by immunological stimulus --- p.106 / Chapter 4.3.2.2 --- Histamine release induced by chemical secretagogues --- p.106 / Chapter 4.3.3 --- Effect of Fructus Ligustri Lucidi (FLL) on histamine release from human mast cells --- p.107 / Chapter 4.3.3.1 --- Histamine release induced by immunological stimulus --- p.107 / Chapter 4.3.3.2 --- Histamine release induced by chemical secretagogues --- p.107 / Chapter 4.3.4 --- Effect of Fructus Psoraleae (FP) on histamine release from human mast cells --- p.108 / Chapter 4.3.4.1 --- Histamine release induced by immunological stimulus --- p.108 / Chapter 4.3.4.2 --- Histamine release induced by chemical secretagogues --- p.109 / Chapter 4.3.5 --- Effect of various partitions from solvent extraction of HEP on histamine release from human mast cells --- p.109 / Chapter 4.3.5.1 --- Histamine release induced by immunological stimulus --- p.110 / Chapter 4.3.5.2 --- Histamine release induced by chemical secretagogue --- p.111 / Chapter 4.3.6 --- Effect of various partitions from solvent extraction of FLL on histamine release from human mast cells --- p.112 / Chapter 4.3.6.1 --- Histamine release induced by immunological stimulus --- p.113 / Chapter 4.3.6.2 --- Histamine release induced by chemical secretagogue --- p.114 / Chapter 4.3.7 --- Effect of ELP and its herbal constituents on the production of cytokine from human mast cells --- p.115 / Chapter 4.3.8 --- Modulation in calcium mobilization in activated human mast cell by ELP and its herbal constituents --- p.117 / Chapter 4.4 --- Discussion --- p.119 / Chapter 5 --- General discussion --- p.163 / Reference --- p.171
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Renal side effects in children who have completed treatment for childhood cancers at Charlotte Maxeke Johannesburg Academic Hospital, South AfricaMudi, Abdullahi 22 April 2015 (has links)
Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Medicine.
Johannesburg, 2014 / Background: The causes of renal dysfunction in children treated for childhood cancers are multifactorial and clinical manifestations of dysfunction include hypertension, proteinuria and varying degrees of renal insufficiency. This study aimed to determine the different residual effects of cancer therapy on the renal system and factors associated with the residual effects in children treated for childhood cancers.
Patients and Methods: The study was a descriptive cross sectional study that assessed 130 children, between the age of 1 and 18 years, who had completed treatment at Charlotte Maxeke Johannesburg Academic Hospital and were being followed up at the paediatric oncology clinic of the hospital.
Results: After a median follow-up post treatment of 2 years, the various manifestations of renal dysfunction identified in the survivors included; decreased GFR, hypomagnesaemia, hypophosphataemia, proteinuria, haematuria and hypertension. In total, 34 survivors (26.15%) had at least one manifestation of renal dysfunction after completing treatment. The most prevalent manifestation of renal dysfunction detected was decreased GFR (17.69%). Hypomagnesaemia and hypophosphataemia were present in 8 (6.15%) and 6 (4.62%) of the survivors respectively. Patients who had renal dysfunction pre-treatment were three times more likely to have renal dysfunction post-treatment. Ifosfamide, Carboplatinum, and nephrectomy were significantly associated with a reduction in GFR
Conclusion: A significant number of the survivors had a decreased GFR while some of them had hypomagnesaemia and hypophosphataemia. There was a strong association between pre-treatment and post-treatment renal dysfunction. These findings are very important in terms of decision making for individual patients with respect to selecting treatment modalities and dosages and also with respect to instituting nephro-protective measures to avoid further damage to the kidneys during and after treatment.
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Examination of Mixed-Effects Models with Nonparametrically Generated DataJanuary 2019 (has links)
abstract: Previous research has shown functional mixed-effects models and traditional mixed-effects models perform similarly when recovering mean and individual trajectories (Fine, Suk, & Grimm, 2019). However, Fine et al. (2019) showed traditional mixed-effects models were able to more accurately recover the underlying mean curves compared to functional mixed-effects models. That project generated data following a parametric structure. This paper extended previous work and aimed to compare nonlinear mixed-effects models and functional mixed-effects models on their ability to recover underlying trajectories which were generated from an inherently nonparametric process. This paper introduces readers to nonlinear mixed-effects models and functional mixed-effects models. A simulation study is then presented where the mean and random effects structure of the simulated data were generated using B-splines. The accuracy of recovered curves was examined under various conditions including sample size, number of time points per curve, and measurement design. Results showed the functional mixed-effects models recovered the underlying mean curve more accurately than the nonlinear mixed-effects models. In general, the functional mixed-effects models recovered the underlying individual curves more accurately than the nonlinear mixed-effects models. Progesterone cycle data from Brumback and Rice (1998) were then analyzed to demonstrate the utility of both models. Both models were shown to perform similarly when analyzing the progesterone data. / Dissertation/Thesis / Doctoral Dissertation Psychology 2019
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Deep electrical characterization and modeling of parasitic effects and degradation mechanisms of AlGaN/GaN HEMTs on SiC substratesRzin, Mehdi 20 July 2015 (has links)
Les travaux de these s’inscrivent dans le cadre de deux projets: ReAGaN et ExtremeGaN avec des industriels (UMS, Serma Technologies, Thales TRT) et des laboratoires derecherche (LEPMI, LAAS et l’université de Bristol).Les deux technologies GaN (GH50 et GH25) étudiées dans cette thèse sont fournies parla société United Monolithic Semiconductors (UMS) et elles ont été qualifiées durant cettethèse. Plusieurs composants ont subi des tests de vieillissement accéléré en températureréalisés par UMS, ensuite une campagne de caractérisation électrique approfondie a étéréalisée au laboratoire IMS afin d’étudier les effets parasites et les mécanismes de dégradationqui limitent la fiabilté de cette filière.Le premier chapitre traite les bases du transistor HEMT à base de GaN. Les avantagesdu matériau nitrure de gallium ainsi que les substrats adaptés au HEMT à base de GaN sontprésentés. Une brève description du marché europeen des composants GaN est donnée.Ensuite, la structure ainsi que le fonctionnement du HEMT AlGaN/GaN sont décrit ainsi queles deux technologies d’UMS.Le deuxième chapitre présente les tests de vieillissement utilisés pour l’analyse defiabilité. Ensuite, un état de l’art des effets parasites et des mécanismes de dégradation desHEMTs AlGaN/GaN est donné. Le projet ReAGaN est décrit et les différentes techniques decaractérisation utilisées durant les travaux de cette thèse sont présentées.Le troisième chapitre est divisé en quatre études de cas ; les trois premières sont dans lecadre du projet ReAGaN et la quatrième dans le cadre du projet Extreme GaN. Dans lapremière étude de cas, les mécanismes de conduction qui augmentent les courants de fuitesdes HEMTs AlGaN/GaN issus de la technologie GH50 ont été étudiés. La deuxième étude decas est dédiée à l’étude d’un effet parasite électrique qui apparait après un vieillissementaccéléré en température sur la caractéristique de la diode Schottky en polarisation directe.Dans la troisième étude de cas, l’influence de la variation de la fraction molaire des HEMTsAlGaN/GaN sur les paramètres électriques a été analysée. La dernière étude de cas consiste enla détermination des limites de fonctionnement et l’aire de sécurité de la technologie GH25d’UMS en réalisant les mesures des lieux de claquage en mode diode et en mode transistor. / This thesis is in the framework of two projects: ReAGaN and Extreme GaN withindustrials (UMS, Serma Technologies, Thales TRT) and academics (LEPMI, LAAS andUniversity of Bristol).The studied AlGaN/GaN HEMTs are provided by the society United MonolithicSemiconductors (UMS) from the GH50 and GH25 GaN processes that were qualified duringthis thesis. Many devices were submitted to high temperature accelerated life tests by UMSand characterized at IMS laboratory to study the parasitic effects and degradationsmechanisms that are limiting the electrical reliability of GaN based HEMTs technology.The first chapter gives an overview of the basics of GaN based high electron mobilitytransistors (HEMTs). Gallium Nitride material features are reviewed as well as substratessuited for GaN based devices. GaN market in Europe and the main industrial actors are listed.Furthermore, the structure and operation of GaN based HEMTs are described. In the last part,the two UMS GaN processes are described.The second chapter presents the life tests that are used for reliability studies. State of theart of parasitic effects and degradation mechanisms of AlGaN/GaN HEMTs is given.Furthermore, the ReAGaN project in which the main part of this thesis is involved isdescribed. The electrical characterization techniques used at IMS during this thesis arepresented.The third chapter is divided into four case studies; three case studies are in theframework of ReAGaN project and the fourth one in the Extreme GaN project. In the firstcase study, we investigate the conduction mechanisms inducing the leakage current inAlGaN/GaN HEMTs issued from GH50 process. The second case study is dedicated to thestudy of an electrical parasitic effect that appears on the Schottky diode forward characteristicafter temperature accelerated life tests. In the third case study, we study the influence of Almole fraction on the DC electrical parameters of AlGaN/GaN HEMTs. The last case studyconsists in the determination of the limits and safe operating area (SOA) of UMS GH25 GaNHEMTs by carrying out the two and three terminal breakdown voltages measurements.
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Radon escape from waterMvelase, Mashinga Johannes January 2010 (has links)
<p>This thesis aims to measure the rate of radon loss from water in a systematic way. The dependence on surface area, temperature and concentration will be investigated. The experiments were done at UWC by creating radon using radium sources and then measuring the radon concentrations inside a vacuum chamber to obtain the speed of radon escape from the water. The results are compared to a model [Cal 2002] where the radon concentration in the air and hence the transfer rate is measured using a RAD7 radon detector. Since the equations cannot be solved analytically, a numerical solution is employed. The radon transfer velocity coefficient is found to be (1.9± / 0.5)× / 10-6m/s. This value indicates that the escape of radon should not be a problem when a sample is open to the air for a minute or two.</p>
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Solvent and vibrational effects on nonlinear optical propertiesMacák, Peter January 2002 (has links)
No description available.
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Theoretical study on nonlinearoptical properties of organicchromophores in solutionsZhao, Ke January 2010 (has links)
Inter-molecular interactions have significant influences on linear and nonlinear optical properties of molecules including one- and two-photon absorptions, emissions, and various high order nonlinear polarizations. The related investigation has become an active and challenging research area. The theoretical structure-to-property relationship obtained from quantum chemical calculations of single organic conjugated molecules often can not be directly applied to real materials in condensed phases. One has to consider the effect of environment, that is, inter-molecular interactions, where the model systems experience in real experiments or applications. The change of molecular conformations under all kinds of interactions and its effects on linear and nonlinear optical properties are the central issue of this thesis. Special attentions have been paid to symmetrical diamino substituted distyrylbenzene chromophores with different torsional angles, two dipolar merocyanine dyes of various orientations, two isomers of a V-shaped 2-hydroxypyrimidine derivative and their various dimers, and the structural fluctuations of interacting polar chromophores in solutions. Quantum chemical methods in combination with molecular dynamics simulations have been employed to study molecular conformations and optical properties in solutions, in particular the solvent and aggregation effects on one- and two-photon absorption. More specifically, time-dependent density functional theory has been used for all electronic calculations, while the polarizable continuum model and supermolecule approach have also been employed to take into account solvent effects. Moreover, the propagation of an ultrashort laser pulse through a one-dimensional asymmetric organic molecular medium which possesses large permanent dipole moments has been simulated by solving full Maxwell-Bloch equations using predictor-corrector finite-difference time-domain method. We have focused on the supercontinuum generation of spectra and the formation of attosecond pulses. / QC20100630
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Den ekonomiska nettoeffekten av mottagna flyktingar i enskild kommun : fallet Karlstad / The net economic impact of refugees received in an individual municipality : case study of KarlstadBruhn, David, Modén, Sara January 2013 (has links)
Flyktingmottagande är en viktig och högst aktuell fråga idag. Flyktingströmmarna till Sverige ökar då oron i andra länder ökar. Detta leder till att frågor uppstår kring mottagandet och de effekter detta skapar. I Sverige förhandlar Länsstyrelserna på uppdrag av staten med kommunerna om hur många flyktingar respektive kommun ska ta emot. I dessa förhandlingar uppstår frågor kring effekterna av mottagandet och vissa frågor är svåra, om inte omöjliga att besvara. Frågan kring vilka ekonomiska nettoeffekter flyktingmottagandet skapar kunde inte länsstyrelserna besvara. Detta visade sig svårt att reda ut då forskning på området var svår att hitta. Denna uppsats försöker undersöka den ekonomiska nettoeffekten av flyktingmottagandet men undersöker också några särskilt intressanta faktorer som påverkar antalet flyktingar en kommun väljer att ta emot. Författarna har utgått från forskning som undersöker nationella nettoeffekter av flyktingmottagandet och försökt anpassa denna forskning till kommunala förhållanden. Den nationella forskningen har sedan använts för att försöka besvara frågan om kommuner kan förvänta sig positiva eller negativa ekonomiska nettoeffekter av mottagandet. Statistik förs på vissa nivåer men inte i en tillfredsställande omfattning vilket ger en skev, om inte direkt missvisande bild av hur det faktiskt ser ut i kommunerna. Därför har författarna valt att inte uppskatta en totalsiffra på de nettoeffekter som uppstår. Uppsatsen tar dock hänsyn till de ersättningar kommunerna får från staten för mottagandet men också de effekter som uppstår i kommunala utjämningssystemet. För att kunna förklara effekterna som uppstår till följd av utjämningssystemet har systemet förklarats utförligt. Uppsatsen försöker således bena ut de direkta ersättningar kommunerna erhåller från staten för mottagandet, de största utgiftsposterna en kommun väntas ha samt vilka effekter som uppstår i det kommunala utjämningssystemet till följd av mottagandet. / The reception of refugees is an important and highly current topic today. Refugee flows to Sweden increases as unrest in other countries increases. This leads to that issues arise around the refugee reception and the effects it create. In Sweden, the county administrative boards (länsstyrelser) are negotiating on behalf of the state with municipalities on how many refugees each municipality are prepared to welcome. In these negotiations, questions arise regarding the impact of the reception and some issues are difficult, if not impossible to answer. The county administrative boards were unable to answer the question about what net economic impact arises, as an effect of the refugee reception. And, because of lack of research it proved difficult to answer the question even when doing research for this thesis. This thesis tries to explore the net economic effects, but also some particularly interesting factors that affect the number of refugees a municipality chooses to welcome. The authors have based this thesis on research that investigates the national net impact of refugee reception, and tried to adapt the research to local conditions. National research has been used to try to answer the question whether municipalities can expect positive or negative net economic impact of the reception Statistics are kept on some levels but not to a satisfactory extent resulting in a skewed, if not outright misleading picture, of how it actually looks in the municipalities. Therefore, the authors have chosen not to estimate a total figure on the net effects that arise. The thesis does, however, discuss the benefits municipalities receive from the state for the reception. Furthermore the thesis discusses the effects that arise in the municipal equalization system. In order to explain the effect caused by the municipal equalization system, this system has been explained fairly detailed. This thesis thus tries to sort out the direct payments the municipalities receive from the state for the reception, as well as the largest expenditures the municipalities is expected to have. Also the effects in the municipal equalization system is sorted out.
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Institutional requirements for watershed cumulative effects assessment in the south Saskatchewan watershedSheelanere, Poornima 29 June 2010
Watersheds in Canada are under increasing threats due to the cumulative environmental
effects from natural and anthropogenic sources. Cumulative effect assessment (CEA),
however, if done at all is typically done on a project-by-project basis. This project-based
approach to CEA is not sufficient to address the cumulative effects of multiple stressors
in a watershed or a region. As a result, there is now a general consensus that CEA must
extend from the project to the more regional scale. The problem, however, is that while
the science of how to do watershed CEA (W-CEA) is progressing, the appropriate
institutional arrangements to sustain W-CEA have not been addressed. Based on a case
study of the South Saskatchewan Watershed (SSW), this research is aimed to identify the
institutional requirements necessary to support and sustain W-CEA.<p>
The research methods include document reviews and semi-structured interviews with
regulators, administrators, watershed coordinators, practitioners, and academics
knowledgeable on cumulative effect assessment and project-based environmental
assessments (EAs). The findings from this research are presented thematically. First,
participants perspectives on cumulative effects, the current state of CEA practice, and
general challenges to project-based approaches to CEA are presented. The concept of WCEA
is then examined, with a discussion on the need for linking project-based CEA and
W-CEA. This is followed by the institutional requirements for W-CEA. The Chapter
concludes with foreseeable challenges to implementing W-CEA, as identified by research
participants.<p>
The key findings include that cumulative effect assessments under project-based EAs are
rarely undertaken in the SSW, and the project-based EA approach is faced with
considerable challenges. The project-based EA challenges suggested by interview
participants are similar to the ones discussed in the literature, and are primarily related to
the lack of guidance to proponents regarding boundaries of assessments and thresholds,
the lack of data from other project EAs, and the lack of capacity of both proponents and
regulators to achieve a good CEA under project EA. These challenges could be addressed
by establishing regional objectives at a broader scale, which could provide better context
to project-based approaches. Further, interview results revealed several opportunities for
the government to take the lead in implementing and sustaining W-CEA, but a multistakeholder
approach is essential to W-CEA success. The results also suggest that the
establishments of thresholds and data management are necessary components of W-CEA,
but that the need for legislation concerning such thresholds and W-CEA initiatives is not
agreed upon. At the same time, research results emphasize that the coordination and
education among various stakeholders will be difficult to achieve. The lack of financial
commitment, political will, and difficulties in establishing cause-effect relationships
currently impede the implementation of W-CEA.
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