940 resultados para quality function development
Resumo:
Nontraditional students differ from traditional students on characteristics such as age, employment status, marital status, and parental status. The quality of a student's experience is important as it relates to his or her transformation and is a reflection of the quality of the college. Using theory of involvement as a framework, the purpose of this study was to test if there were differences between traditional and nontraditional undergraduate students in their ratings of quality of college involvement (academic, co-curricular, student interactions, and faculty interactions) and perceptions of college contribution toward development (intellectual, personal, social, and career). A two part survey was distributed to a random cluster sample of sophomore and higher level undergraduate classes equaling 400 undergraduate students. Results of a 2 X 4 repeated measures ANOVA indicated that traditional students rated quality for co-curricular involvement and student involvement significantly higher than nontraditional students. Both traditional and nontraditional students had similar ratings of college contribution toward development. There were different patterns of correlations between involvement and development. Traditional students' ratings of academic and student involvement were more highly correlated with development than were the ratings of nontraditional students. However, nontraditional students' ratings of academic and faculty involvement were more highly correlated with development. When testing for differences in correlations between quality of involvement and college contribution toward development, the largest observed differences were quality of student involvement and college contribution toward personal and social development. Although not significantly different, traditional students had stronger correlations between those factors than did the nontraditional students. This research demonstrates the importance of using social role when defining student type. It contributes to involvement theory by explaining how traditional and nontraditional students differ in their ratings of quality of involvement. Further, it identifies different patterns of correlations between ratings of quality of involvement and college contribution toward development for the two types of students. While traditional students may need a more rounded college experience that includes more social and co-curricular experiences, nontraditional students use the classroom as their stage for learning.
Resumo:
Using survey data from 358 online customers, the study finds that the e-service quality construct conforms to the structure of a third-order factor model that links online service quality perceptions to distinct and actionable dimensions, including (1) website design, (2) fulfilment, (3) customer service, and (4) security/privacy. Each dimension is found to consist of several attributes that define the basis of e-service quality perceptions. A comprehensive specification of the construct, which includes attributes not covered in existing scales, is developed. The study contrasts a formative model consisting of 4 dimensions and 16 attributes against a reflective conceptualization. The results of this comparison indicate that studies using an incorrectly specified model overestimate the importance of certain e-service quality attributes. Global fit criteria are also found to support the detection of measurement misspecification. Meta-analytic data from 31,264 online customers are used to show that the developed measurement predicts customer behavior better than widely used scales, such as WebQual and E-S-Qual. The results show that the new measurement enables managers to assess e-service quality more accurately and predict customer behavior more reliably.
Resumo:
Knowledge-based radiation treatment is an emerging concept in radiotherapy. It
mainly refers to the technique that can guide or automate treatment planning in
clinic by learning from prior knowledge. Dierent models are developed to realize
it, one of which is proposed by Yuan et al. at Duke for lung IMRT planning. This
model can automatically determine both beam conguration and optimization ob-
jectives with non-coplanar beams based on patient-specic anatomical information.
Although plans automatically generated by this model demonstrate equivalent or
better dosimetric quality compared to clinical approved plans, its validity and gener-
ality are limited due to the empirical assignment to a coecient called angle spread
constraint dened in the beam eciency index used for beam ranking. To eliminate
these limitations, a systematic study on this coecient is needed to acquire evidences
for its optimal value.
To achieve this purpose, eleven lung cancer patients with complex tumor shape
with non-coplanar beams adopted in clinical approved plans were retrospectively
studied in the frame of the automatic lung IMRT treatment algorithm. The primary
and boost plans used in three patients were treated as dierent cases due to the
dierent target size and shape. A total of 14 lung cases, thus, were re-planned using
the knowledge-based automatic lung IMRT planning algorithm by varying angle
spread constraint from 0 to 1 with increment of 0.2. A modied beam angle eciency
index used for navigate the beam selection was adopted. Great eorts were made to assure the quality of plans associated to every angle spread constraint as good
as possible. Important dosimetric parameters for PTV and OARs, quantitatively
re
ecting the plan quality, were extracted from the DVHs and analyzed as a function
of angle spread constraint for each case. Comparisons of these parameters between
clinical plans and model-based plans were evaluated by two-sampled Students t-tests,
and regression analysis on a composite index built on the percentage errors between
dosimetric parameters in the model-based plans and those in the clinical plans as a
function of angle spread constraint was performed.
Results show that model-based plans generally have equivalent or better quality
than clinical approved plans, qualitatively and quantitatively. All dosimetric param-
eters except those for lungs in the automatically generated plans are statistically
better or comparable to those in the clinical plans. On average, more than 15% re-
duction on conformity index and homogeneity index for PTV and V40, V60 for heart
while an 8% and 3% increase on V5, V20 for lungs, respectively, are observed. The
intra-plan comparison among model-based plans demonstrates that plan quality does
not change much with angle spread constraint larger than 0.4. Further examination
on the variation curve of the composite index as a function of angle spread constraint
shows that 0.6 is the optimal value that can result in statistically the best achievable
plans.
Resumo:
B cells mediate immune responses via the secretion of antibody and interactions with other immune cell populations through antigen presentation, costimulation, and cytokine secretion. Although B cells are primarily believed to promote immune responses using the mechanisms described above, some unique regulatory B cell populations that negatively influence inflammation have also been described. Among these is a rare interleukin (IL)-10-producing B lymphocyte subset termed “B10 cells.” B cell-derived IL-10 can inhibit various arms of the immune system, including polarization of Th1/Th2 cell subsets, antigen presentation and cytokine production by monocytes and macrophages, and activation of regulatory T cells. Further studies in numerous autoimmune and inflammatory models of disease have confirmed the ability of B10 cells to negatively regulate inflammation in an IL-10-dependent manner. Although IL-10 is indispensable to the effector functions of B10 cells, how this specialized B cell population is selected in vivo to produce IL-10 is unknown. Some studies have demonstrated a link between B cell receptor (BCR)-derived signals and the acquisition of IL-10 competence. Additionally, whether antigen-BCR interactions are required for B cell IL-10 production during homeostasis as well as active immune responses is a matter of debate. Therefore, the goal of this thesis is to determine the importance of antigen-driven signals during B10 cell development in vivo and during B10 cell-mediated immunosuppression.
Chapter 3 of the dissertation explored the BCR repertoire of spleen and peritoneal cavity B10 cells using single-cell sequencing to lay the foundation for studies to understand the full range of antigens that may be involved in B10 cell selection. In both the spleen and peritoneal cavity B10 cells studied, BCR gene utilization was diverse, and the expressed BCR transcripts were largely unmutated. Thus, B10 cells are likely capable of responding to a wide range of foreign and self-antigens in vivo.
Studies in Chapter 4 determined the predominant antigens that drive B cell IL-10 secretion during homeostasis. A novel in vitro B cell expansion system was used to isolate B cells actively expressing IL-10 in vivo and probe the reactivities of their secreted monoclonal antibodies. B10 cells were found to produce polyreactive antibodies that bound multiple self-antigens. Therefore, in the absence of overarching active immune responses, B cell IL-10 is secreted following interactions with self-antigens.
Chapter 5 of this dissertation investigated whether foreign antigens are capable of driving B10 cell expansion and effector activity during an active immune response. In a model of contact-induced hypersensitivity, in vitro B cell expansion was again used to isolate antigen-specific B10 clones, which were required for optimal immunosuppression.
The studies described in this dissertation shed light on the relative contributions of BCR-derived signals during B10 cell development and effector function. Furthermore, these investigations demonstrate that B10 cells respond to both foreign and self-antigens, which has important implications for the potential manipulation of B10 cells for human therapy. Therefore, B10 cells represent a polyreactive B cell population that provides antigen-specific regulation of immune responses via the production of IL-10.
Resumo:
La spectrométrie de masse mesure la masse des ions selon leur rapport masse sur charge. Cette technique est employée dans plusieurs domaines et peut analyser des mélanges complexes. L’imagerie par spectrométrie de masse (Imaging Mass Spectrometry en anglais, IMS), une branche de la spectrométrie de masse, permet l’analyse des ions sur une surface, tout en conservant l’organisation spatiale des ions détectés. Jusqu’à présent, les échantillons les plus étudiés en IMS sont des sections tissulaires végétales ou animales. Parmi les molécules couramment analysées par l’IMS, les lipides ont suscité beaucoup d'intérêt. Les lipides sont impliqués dans les maladies et le fonctionnement normal des cellules; ils forment la membrane cellulaire et ont plusieurs rôles, comme celui de réguler des événements cellulaires. Considérant l’implication des lipides dans la biologie et la capacité du MALDI IMS à les analyser, nous avons développé des stratégies analytiques pour la manipulation des échantillons et l’analyse de larges ensembles de données lipidiques. La dégradation des lipides est très importante dans l’industrie alimentaire. De la même façon, les lipides des sections tissulaires risquent de se dégrader. Leurs produits de dégradation peuvent donc introduire des artefacts dans l’analyse IMS ainsi que la perte d’espèces lipidiques pouvant nuire à la précision des mesures d’abondance. Puisque les lipides oxydés sont aussi des médiateurs importants dans le développement de plusieurs maladies, leur réelle préservation devient donc critique. Dans les études multi-institutionnelles où les échantillons sont souvent transportés d’un emplacement à l’autre, des protocoles adaptés et validés, et des mesures de dégradation sont nécessaires. Nos principaux résultats sont les suivants : un accroissement en fonction du temps des phospholipides oxydés et des lysophospholipides dans des conditions ambiantes, une diminution de la présence des lipides ayant des acides gras insaturés et un effet inhibitoire sur ses phénomènes de la conservation des sections au froid sous N2. A température et atmosphère ambiantes, les phospholipides sont oxydés sur une échelle de temps typique d’une préparation IMS normale (~30 minutes). Les phospholipides sont aussi décomposés en lysophospholipides sur une échelle de temps de plusieurs jours. La validation d’une méthode de manipulation d’échantillon est d’autant plus importante lorsqu’il s’agit d’analyser un plus grand nombre d’échantillons. L’athérosclérose est une maladie cardiovasculaire induite par l’accumulation de matériel cellulaire sur la paroi artérielle. Puisque l’athérosclérose est un phénomène en trois dimension (3D), l'IMS 3D en série devient donc utile, d'une part, car elle a la capacité à localiser les molécules sur la longueur totale d’une plaque athéromateuse et, d'autre part, car elle peut identifier des mécanismes moléculaires du développement ou de la rupture des plaques. l'IMS 3D en série fait face à certains défis spécifiques, dont beaucoup se rapportent simplement à la reconstruction en 3D et à l’interprétation de la reconstruction moléculaire en temps réel. En tenant compte de ces objectifs et en utilisant l’IMS des lipides pour l’étude des plaques d’athérosclérose d’une carotide humaine et d’un modèle murin d’athérosclérose, nous avons élaboré des méthodes «open-source» pour la reconstruction des données de l’IMS en 3D. Notre méthodologie fournit un moyen d’obtenir des visualisations de haute qualité et démontre une stratégie pour l’interprétation rapide des données de l’IMS 3D par la segmentation multivariée. L’analyse d’aortes d’un modèle murin a été le point de départ pour le développement des méthodes car ce sont des échantillons mieux contrôlés. En corrélant les données acquises en mode d’ionisation positive et négative, l’IMS en 3D a permis de démontrer une accumulation des phospholipides dans les sinus aortiques. De plus, l’IMS par AgLDI a mis en évidence une localisation différentielle des acides gras libres, du cholestérol, des esters du cholestérol et des triglycérides. La segmentation multivariée des signaux lipidiques suite à l’analyse par IMS d’une carotide humaine démontre une histologie moléculaire corrélée avec le degré de sténose de l’artère. Ces recherches aident à mieux comprendre la complexité biologique de l’athérosclérose et peuvent possiblement prédire le développement de certains cas cliniques. La métastase au foie du cancer colorectal (Colorectal cancer liver metastasis en anglais, CRCLM) est la maladie métastatique du cancer colorectal primaire, un des cancers le plus fréquent au monde. L’évaluation et le pronostic des tumeurs CRCLM sont effectués avec l’histopathologie avec une marge d’erreur. Nous avons utilisé l’IMS des lipides pour identifier les compartiments histologiques du CRCLM et extraire leurs signatures lipidiques. En exploitant ces signatures moléculaires, nous avons pu déterminer un score histopathologique quantitatif et objectif et qui corrèle avec le pronostic. De plus, par la dissection des signatures lipidiques, nous avons identifié des espèces lipidiques individuelles qui sont discriminants des différentes histologies du CRCLM et qui peuvent potentiellement être utilisées comme des biomarqueurs pour la détermination de la réponse à la thérapie. Plus spécifiquement, nous avons trouvé une série de plasmalogènes et sphingolipides qui permettent de distinguer deux différents types de nécrose (infarct-like necrosis et usual necrosis en anglais, ILN et UN, respectivement). L’ILN est associé avec la réponse aux traitements chimiothérapiques, alors que l’UN est associé au fonctionnement normal de la tumeur.
Resumo:
Aims. To validate the Swedish version of the Sheffield Care Environment Assessment Matrix (S-SCEAM). The instrument’s items measure environmental elements important for supporting the needs of older people, and conceptualized within eight domains. Methods. Item relevance was assessed by a group of experts and measured using content validity index (CVI). Test-retest and inter-rater reliability tests were performed. The domain structure was assessed by the inter-rater agreement of a second group of experts, and measured using Fleiss kappa. Results. All items attained a CVI above 0.78, the suggested criteria for excellent content validity. Test-retest reliability showed high stability (96% and 95% for two independent raters respectively), and inter-rater reliability demonstrated high levels of agreement (95% and 94% on two separate rating occasions). Kappa values were very good for test-retest (κ = 0.903 and 0.869) and inter-rater reliability (κ = 0.851 and 0.832). Domain structure was good, Fleiss’ kappa was 0.63 (range 0.45 to 0.75). Conclusion. The S-SCEAM of 210 items and eight domains showed good content validity and construct validity. The instrument is suggested for use in measuring of the quality of the physical environment in residential care facilities for older persons.
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Thesis (Master's)--University of Washington, 2016-08
Resumo:
Report on the High Quality Jobs Program (HQJP) and the Grow Iowa Values Fund (GIVF), administered by the Iowa Economic Development Authority (IEDA), previously known as the Department of Economic Development, for the period July 1, 2003 through June 30, 2014
Resumo:
Nervous system disorders are associated with cognitive and motor deficits, and are responsible for the highest disability rates and global burden of disease. Their recovery paths are vulnerable and dependent on the effective combination of plastic brain tissue properties, with complex, lengthy and expensive neurorehabilitation programs. This work explores two lines of research, envisioning sustainable solutions to improve treatment of cognitive and motor deficits. Both projects were developed in parallel and shared a new sensible approach, where low-cost technologies were integrated with common clinical operative procedures. The aim was to achieve more intensive treatments under specialized monitoring, improve clinical decision-making and increase access to healthcare. The first project (articles I – III) concerned the development and evaluation of a web-based cognitive training platform (COGWEB), suitable for intensive use, either at home or at institutions, and across a wide spectrum of ages and diseases that impair cognitive functioning. It was tested for usability in a memory clinic setting and implemented in a collaborative network, comprising 41 centers and 60 professionals. An adherence and intensity study revealed a compliance of 82.8% at six months and an average of six hours/week of continued online cognitive training activities. The second project (articles IV – VI) was designed to create and validate an intelligent rehabilitation device to administer proprioceptive stimuli on the hemiparetic side of stroke patients while performing ambulatory movement characterization (SWORD). Targeted vibratory stimulation was found to be well tolerated and an automatic motor characterization system retrieved results comparable to the first items of the Wolf Motor Function Test. The global system was tested in a randomized placebo controlled trial to assess its impact on a common motor rehabilitation task in a relevant clinical environment (early post-stroke). The number of correct movements on a hand-to-mouth task was increased by an average of 7.2/minute while the probability to perform an error decreased from 1:3 to 1:9. Neurorehabilitation and neuroplasticity are shifting to more neuroscience driven approaches. Simultaneously, their final utility for patients and society is largely dependent on the development of more effective technologies that facilitate the dissemination of knowledge produced during the process. The results attained through this work represent a step forward in that direction. Their impact on the quality of rehabilitation services and public health is discussed according to clinical, technological and organizational perspectives. Such a process of thinking and oriented speculation has led to the debate of subsequent hypotheses, already being explored in novel research paths.
Resumo:
Mammography equipment must be evaluated to ensure that images will be of acceptable diagnostic quality with lowest radiation dose. Quality Assurance (QA) aims to provide systematic and constant improvement through a feedback mechanism to address the technical, clinical and training aspects. Quality Control (QC), in relation to mammography equipment, comprises a series of tests to determine equipment performance characteristics. The introduction of digital technologies promoted changes in QC tests and protocols and there are some tests that are specific for each manufacturer. Within each country specifi c QC tests should be compliant with regulatory requirements and guidance. Ideally, one mammography practitioner should take overarching responsibility for QC within a service, with all practitioners having responsibility for actual QC testing. All QC results must be documented to facilitate troubleshooting, internal audit and external assessment. Generally speaking, the practitioner’s role includes performing, interpreting and recording the QC tests as well as reporting any out of action limits to their service lead. They must undertake additional continuous professional development to maintain their QC competencies. They are usually supported by technicians and medical physicists; in some countries the latter are mandatory. Technicians and/or medical physicists often perform many of the tests indicated within this chapter. It is important to recognise that this chapter is an attempt to encompass the main tests performed within European countries. Specific tests related to the service that you work within must be familiarised with and adhered too.
Resumo:
The problem: Around 300 million people worldwide have asthma and prevalence is increasing. Support for optimal self-management can be effective in improving a range of outcomes and is cost effective, but is underutilised as a treatment strategy. Supporting optimum self-management using digital technology shows promise, but how best to do this is not clear. Aim: The purpose of this project was to explore the potential role of a digital intervention in promoting optimum self-management in adults with asthma. Methods: Following the MRC Guidance on the Development and Evaluation of Complex Interventions which advocates using theory, evidence, user testing and appropriate modelling and piloting, this project had 3 phases. Phase 1: Examination of the literature to inform phases 2 and 3, using systematic review methods and focussed literature searching. Phase 2: Developing the Living Well with Asthma website. A prototype (paper-based) version of the website was developed iteratively with input from a multidisciplinary expert panel, empirical evidence from the literature (from phase 1), and potential end users via focus groups (adults with asthma and practice nurses). Implementation and behaviour change theories informed this process. The paper-based designs were converted to the website through an iterative user centred process (think aloud studies with adults with asthma). Participants considered contents, layout, and navigation. Development was agile using feedback from the think aloud sessions immediately to inform design and subsequent think aloud sessions. Phase 3: A pilot randomised controlled trial over 12 weeks to evaluate the feasibility of a Phase 3 trial of Living Well with Asthma to support self-management. Primary outcomes were 1) recruitment & retention; 2) website use; 3) Asthma Control Questionnaire (ACQ) score change from baseline; 4) Mini Asthma Quality of Life (AQLQ) score change from baseline. Secondary outcomes were patient activation, adherence, lung function, fractional exhaled nitric oxide (FeNO), generic quality of life measure (EQ-5D), medication use, prescribing and health services contacts. Results: Phase1: Demonstrated that while digital interventions show promise, with some evidence of effectiveness in certain outcomes, participants were poorly characterised, telling us little about the reach of these interventions. The interventions themselves were poorly described making drawing definitive conclusions about what worked and what did not impossible. Phase 2: The literature indicated that important aspects to cover in any self-management intervention (digital or not) included: asthma action plans, regular health professional review, trigger avoidance, psychological functioning, self-monitoring, inhaler technique, and goal setting. The website asked users to aim to be symptom free. Key behaviours targeted to achieve this include: optimising medication use (including inhaler technique); attending primary care asthma reviews; using asthma action plans; increasing physical activity levels; and stopping smoking. The website had 11 sections, plus email reminders, which promoted these behaviours. Feedback during think aloud studies was mainly positive with most changes focussing on clarification of language, order of pages and usability issues mainly relating to navigation difficulties. Phase 3: To achieve our recruitment target 5383 potential participants were invited, leading to 51 participants randomised (25 to intervention group). Age range 16-78 years; 75% female; 28% from most deprived quintile. Nineteen (76%) of the intervention group used the website for an average of 23 minutes. Non-significant improvements in favour of the intervention group observed in the ACQ score (-0.36; 95% confidence interval: -0.96, 0.23; p=0.225), and mini-AQLQ scores (0.38; -0.13, 0.89; p=0.136). A significant improvement was observed in the activity limitation domain of the mini-AQLQ (0.60; 0.05 to 1.15; p = 0.034). Secondary outcomes showed increased patient activation and reduced reliance on reliever medication. There was no significant difference in the remaining secondary outcomes. There were no adverse events. Conclusion: Living Well with Asthma has been shown to be acceptable to potential end users, and has potential for effectiveness. This intervention merits further development, and subsequent evaluation in a Phase III full scale RCT.
Resumo:
Postharvest disease management is one of the key challenges in commercial mango supply chains. Comprehensive investigations were made regarding the impact of geographic locality on postharvest disease development and other quality parameters in 'Sindhri' and 'Samar Bahisht (S.B.) Chaunsa' mangoes under ambient (33±1°C; 55-60% RH) and low temperature storage/simulated shipping (12±1°C; 80- 85% RH) conditions (28 or 35 days storage for 'Sindhri' and 21 or 28 days for 'S.B. Chaunsa'). Physiologically mature (days from fruit set were 95-100 and 110-115 for 'Sindhri' and 'S.B Chaunsa', respectively) 'Sindhri' and 'S.B. Chaunsa' fruits were harvested from five geographic localities and subjected to ambient and simulated shipping conditions. Under ambient conditions, no disease incidence was observed till fruit eating stage in 'Sindhri'. However, in 'S.B. Chaunsa', significant variation in different localities was observed with respect to disease incidence. Maximum and at par disease was exhibited by the fruit collected from district Vehari and Khanewal in 'S.B. Chaunsa'. Under simulated shipping conditions, disease development varied significantly with respect to different locations and storage durations. In 'Sindhri', fruit of M. Garh, while, 'S.B. Chaunsa' fruit of districts R.Y. Khan, M. Garh and Khanewal showed higher disease incidence. Fruit peel colour development was significantly reduced as storage days increased. Fruit firmness, skin shriveling, fresh weight loss, dry matter, biochemical and organoleptic attributes also varied significantly among the fruit sourced from different orchards of different localities. Analysis of N contents in leaves and fruit peel revealed that N contents of leaf and peel were positively correlated with disease severity in mango. Botryodiplodia spp., Phomopsis mangiferae, Alternaria alternata, Colletotrichum gloeosporioides were the pathogens isolated from fruits of all locations; however, the prevalence frequency varied with the geographic localities. In conclusion, the production locality, cultivar and nutrition (nitrogen content of fruit peel) had significant effect on fruit quality out-turn at ripe stage in terms of disease development so area specific disease management system needs to be implemented for better quality at retail.
Resumo:
La spectrométrie de masse mesure la masse des ions selon leur rapport masse sur charge. Cette technique est employée dans plusieurs domaines et peut analyser des mélanges complexes. L’imagerie par spectrométrie de masse (Imaging Mass Spectrometry en anglais, IMS), une branche de la spectrométrie de masse, permet l’analyse des ions sur une surface, tout en conservant l’organisation spatiale des ions détectés. Jusqu’à présent, les échantillons les plus étudiés en IMS sont des sections tissulaires végétales ou animales. Parmi les molécules couramment analysées par l’IMS, les lipides ont suscité beaucoup d'intérêt. Les lipides sont impliqués dans les maladies et le fonctionnement normal des cellules; ils forment la membrane cellulaire et ont plusieurs rôles, comme celui de réguler des événements cellulaires. Considérant l’implication des lipides dans la biologie et la capacité du MALDI IMS à les analyser, nous avons développé des stratégies analytiques pour la manipulation des échantillons et l’analyse de larges ensembles de données lipidiques. La dégradation des lipides est très importante dans l’industrie alimentaire. De la même façon, les lipides des sections tissulaires risquent de se dégrader. Leurs produits de dégradation peuvent donc introduire des artefacts dans l’analyse IMS ainsi que la perte d’espèces lipidiques pouvant nuire à la précision des mesures d’abondance. Puisque les lipides oxydés sont aussi des médiateurs importants dans le développement de plusieurs maladies, leur réelle préservation devient donc critique. Dans les études multi-institutionnelles où les échantillons sont souvent transportés d’un emplacement à l’autre, des protocoles adaptés et validés, et des mesures de dégradation sont nécessaires. Nos principaux résultats sont les suivants : un accroissement en fonction du temps des phospholipides oxydés et des lysophospholipides dans des conditions ambiantes, une diminution de la présence des lipides ayant des acides gras insaturés et un effet inhibitoire sur ses phénomènes de la conservation des sections au froid sous N2. A température et atmosphère ambiantes, les phospholipides sont oxydés sur une échelle de temps typique d’une préparation IMS normale (~30 minutes). Les phospholipides sont aussi décomposés en lysophospholipides sur une échelle de temps de plusieurs jours. La validation d’une méthode de manipulation d’échantillon est d’autant plus importante lorsqu’il s’agit d’analyser un plus grand nombre d’échantillons. L’athérosclérose est une maladie cardiovasculaire induite par l’accumulation de matériel cellulaire sur la paroi artérielle. Puisque l’athérosclérose est un phénomène en trois dimension (3D), l'IMS 3D en série devient donc utile, d'une part, car elle a la capacité à localiser les molécules sur la longueur totale d’une plaque athéromateuse et, d'autre part, car elle peut identifier des mécanismes moléculaires du développement ou de la rupture des plaques. l'IMS 3D en série fait face à certains défis spécifiques, dont beaucoup se rapportent simplement à la reconstruction en 3D et à l’interprétation de la reconstruction moléculaire en temps réel. En tenant compte de ces objectifs et en utilisant l’IMS des lipides pour l’étude des plaques d’athérosclérose d’une carotide humaine et d’un modèle murin d’athérosclérose, nous avons élaboré des méthodes «open-source» pour la reconstruction des données de l’IMS en 3D. Notre méthodologie fournit un moyen d’obtenir des visualisations de haute qualité et démontre une stratégie pour l’interprétation rapide des données de l’IMS 3D par la segmentation multivariée. L’analyse d’aortes d’un modèle murin a été le point de départ pour le développement des méthodes car ce sont des échantillons mieux contrôlés. En corrélant les données acquises en mode d’ionisation positive et négative, l’IMS en 3D a permis de démontrer une accumulation des phospholipides dans les sinus aortiques. De plus, l’IMS par AgLDI a mis en évidence une localisation différentielle des acides gras libres, du cholestérol, des esters du cholestérol et des triglycérides. La segmentation multivariée des signaux lipidiques suite à l’analyse par IMS d’une carotide humaine démontre une histologie moléculaire corrélée avec le degré de sténose de l’artère. Ces recherches aident à mieux comprendre la complexité biologique de l’athérosclérose et peuvent possiblement prédire le développement de certains cas cliniques. La métastase au foie du cancer colorectal (Colorectal cancer liver metastasis en anglais, CRCLM) est la maladie métastatique du cancer colorectal primaire, un des cancers le plus fréquent au monde. L’évaluation et le pronostic des tumeurs CRCLM sont effectués avec l’histopathologie avec une marge d’erreur. Nous avons utilisé l’IMS des lipides pour identifier les compartiments histologiques du CRCLM et extraire leurs signatures lipidiques. En exploitant ces signatures moléculaires, nous avons pu déterminer un score histopathologique quantitatif et objectif et qui corrèle avec le pronostic. De plus, par la dissection des signatures lipidiques, nous avons identifié des espèces lipidiques individuelles qui sont discriminants des différentes histologies du CRCLM et qui peuvent potentiellement être utilisées comme des biomarqueurs pour la détermination de la réponse à la thérapie. Plus spécifiquement, nous avons trouvé une série de plasmalogènes et sphingolipides qui permettent de distinguer deux différents types de nécrose (infarct-like necrosis et usual necrosis en anglais, ILN et UN, respectivement). L’ILN est associé avec la réponse aux traitements chimiothérapiques, alors que l’UN est associé au fonctionnement normal de la tumeur.
Resumo:
The main aim of this study was to analyze evidence of an environmental Kuznets curve for water pollution in the developing and developed countries. The study was conducted based on a panel data set of 54 countries – that were categorized into six groups of “developed countries”, “developing countries”, “developed countries with low income”, “developed countries with high income” and “coastal countries”- between the years 1995 to 2006. The results do not confirm the inverted U-shape of EKC curve for the developed countries with low income. Based on the estimated turning points and the average GDP per capita, the study revealed at which point of the EKC the countries are. Furthermore, impacts of capital-and-labor ratio as well as trade openness are drawn by estimating different models for the EKC. The magnitude role of each explanatory variable on BOD was calculated by estimating the associated elasticity.
Resumo:
Over the past 15 years, the number of international development projects aimed at combating global poverty has increased significantly. Within the water and sanitation sector however, and despite heightened global attention and an increase in the number of infrastructure projects, over 800 million people remain without access to appropriate water and sanitation facilities. The majority of donor aid in the water supply and sanitation sector of developing countries is delivered through standalone projects. The quality of projects at the design and preparation stage is a critical determinant in meeting project objectives. The quality of projects at early stage of design, widely referred to as quality at entry (QAE), however remains unquantified and largely subjective. This research argues that water and sanitation infrastructure projects in the developing world tend to be designed in the absence of a specific set of actions that ensure high QAE, and consequently have relatively high rates of failure. This research analyzes 32 cases of water and sanitation infrastructure projects implemented with partial or full World Bank financing globally from 2000 – 2010. The research uses categorical data analysis, regression analysis and descriptive analysis to examine perceived linkages between project QAE and project development outcomes and determines which upstream project design factors are likely to impact the QAE of international development projects in water supply and sanitation. The research proposes a number of specific design stage actions that can be incorporated into the formal review process of water and sanitation projects financed by the World Bank or other international development partners.