CSR practices and labor retention: How can these variables be related?

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Positive self-image and incentives in organizations

This paper investigates the implications of individuals’ mistaken beliefs of their abilities on incentives in organizations using the principal-agent model of moral hazard. The paper shows that if effort is observable, then an agent’s mistaken beliefs about own ability are always favorable to the principal. However, if effort is unobservable, then an agent’s mistaken beliefs about own ability can be either favorable or unfavorable to the principal. The paper provides conditions under which an agent’s over estimation about own ability is favorable to the principal when effort is unobservable. Finally, the paper shows that workers’ mistaken beliefs about their coworkers’ abilities make interdependent incentive schemes more attractive to firms than individualistic incentive schemes.

Positive self-image in tournaments

This paper analyzes the implications of worker overestimation of productivity for firms in which incentives take the form of tournaments. Each worker overestimates his productivity but is aware of the bias in his opponent’s self-assessment. The manager of the firm, on the other hand, correctly assesses workers’ productivities and self-beliefs when setting tournament prizes. The paper shows that, under a variety of circumstances, firms make higher profits when workers have positive self-image than if workers do not. By contrast, workers’ welfare declines due to their own misguided choices.

Microscopy image segmentation by active contour models

In this thesis a semi-automated cell analysis system is described through image processing. To achieve this, an image processing algorithm was studied in order to segment cells in a semi-automatic way. The main goal of this analysis is to increase the performance of cell image segmentation process, without affecting the results in a significant way. Even though, a totally manual system has the ability of producing the best results, it has the disadvantage of taking too long and being repetitive, when a large number of images need to be processed. An active contour algorithm was tested in a sequence of images taken by a microscope. This algorithm, more commonly known as snakes, allowed the user to define an initial region in which the cell was incorporated. Then, the algorithm would run several times, making the initial region contours to converge to the cell boundaries. With the final contour, it was possible to extract region properties and produce statistical data. This data allowed to say that this algorithm produces similar results to a purely manual system but at a faster rate. On the other hand, it is slower than a purely automatic way but it allows the user to adjust the contour, making it more versatile and tolerant to image variations.

Optimization of breast tomosynthesis image reconstruction using parallel computing

Breast cancer is the most common cancer among women, being a major public health problem. Worldwide, X-ray mammography is the current gold-standard for medical imaging of breast cancer. However, it has associated some well-known limitations. The false-negative rates, up to 66% in symptomatic women, and the false-positive rates, up to 60%, are a continued source of concern and debate. These drawbacks prompt the development of other imaging techniques for breast cancer detection, in which Digital Breast Tomosynthesis (DBT) is included. DBT is a 3D radiographic technique that reduces the obscuring effect of tissue overlap and appears to address both issues of false-negative and false-positive rates. The 3D images in DBT are only achieved through image reconstruction methods. These methods play an important role in a clinical setting since there is a need to implement a reconstruction process that is both accurate and fast. This dissertation deals with the optimization of iterative algorithms, with parallel computing through an implementation on Graphics Processing Units (GPUs) to make the 3D reconstruction faster using Compute Unified Device Architecture (CUDA). Iterative algorithms have shown to produce the highest quality DBT images, but since they are computationally intensive, their clinical use is currently rejected. These algorithms have the potential to reduce patient dose in DBT scans. A method of integrating CUDA in Interactive Data Language (IDL) is proposed in order to accelerate the DBT image reconstructions. This method has never been attempted before for DBT. In this work the system matrix calculation, the most computationally expensive part of iterative algorithms, is accelerated. A speedup of 1.6 is achieved proving the fact that GPUs can accelerate the IDL implementation.

Utilidade da tomografia computorizada cardíaca na avaliação da doença coronária

RESUMO: Apesar de toda a evolução farmacológica e de meios complementares de diagnóstico possível nos últimos anos, o enfarte agudo do miocárdio e a morte súbita continuam a ser a primeira manifestação da aterosclerose coronária para muitos doentes, que estavam previamente assintomáticos. Os exames complementares de diagnóstico tradicionalmente usados para avaliar a presença de doença coronária, baseiam‐se na documentação de isquémia do miocárdio e por este motivo a sua positividade depende da presença de lesões coronárias obstrutivas. As lesões coronárias não obstrutivas estão também frequentemente implicadas no desenvolvimento de eventos coronários. Apesar de o risco absoluto de instabilização por placa ser superior para as lesões mais volumosas e obstrutivas, estas são menos prevalentes do que as placas não obstrutivas e assim, por questões probabilísticas, os eventos coronários resultam com frequência da rotura ou erosão destas últimas. Estudos recentes de imagiologia intracoronária avançada forneceram evidência de que apesar de ser possível identificar algumas características de vulnerabilidade em placas associadas ao desenvolvimento subsequente de eventos coronários, a sua sensibilidade e especificidade é muito baixa para aplicação clínica. Mais do que o risco associado a uma placa em particular, para o doente poderá ser mais importante o risco global da sua árvore coronária reflexo da soma das probabilidade de todas as suas lesões, sendo que quanto maior for a carga aterosclerótica maior será o seu risco. A angio TC cardíaca é a mais recente técnica de imagem não invasiva para o estudo da doença coronária e surgiu nos últimos anos fruto de importantes avanços na tecnologia de TC multidetectores. Estes avanços, permitiram uma progressiva melhoria da resolução espacial e temporal, contribuindo para a melhoria da qualidade dos exames, bem como uma significativa redução da dose de radiação. A par desta evolução tecnológica, foi aumentando a experiência e gerada mais evidência científica, tornando a angio TC cardíaca cada vez mais robusta na avaliação da doença coronária e aumentando a sua aplicabilidade clínica. Mais recentemente apareceram vários trabalhos que validaram o seu valor prognóstico, assinalando a sua chegada à idade adulta. Para além de permitir excluir a presença de doença coronária e de identificar a presença de estenoses significativas, a angio TC cardíaca permite identificar a presença de lesões coronárias não obstrutivas, característica impar desta técnica como modalidade de imagem não invasiva. Ao permitir identificar a totalidade das lesões ateroscleróticas (obstrutivas e não obstrutivas), a 18 angio TC cardíaca poderá fornecer uma quantificação da carga aterosclerótica coronária total, podendo essa identificação ser útil na estratificação dos indivíduos em risco de eventos coronários. Neste trabalho foi possível identificar preditores demográficos e clínicos de uma elevada carga aterosclerótica coronária documentada pela angioTC cardíaca, embora o seu poder discriminativo tenha sido relativamente modesto, mesmo quando agrupados em scores clínicos. Entre os vários scores, o desempenho foi um pouco melhor para o score de risco cardiovascular Heartscore. Estas limitações espelham a dificuldade de prever apenas com base em variáveis clínicas, mesmo quando agrupadas em scores, a presença e extensão da doença coronária. Um dos factores de risco clássicos, a obesidade, parece ter uma relação paradoxal com a carga aterosclerótica, o que pode justificar algumas limitações da estimativa com base em scores clínicos. A diabetes mellitus, por outro lado, foi um dos preditores clínicos mais importantes, funcionando como modelo de doença coronária mais avançada, útil para avaliar o desempenho dos diferentes índices de carga aterosclerótica. Dada a elevada prevalência de placas ateroscleróticas identificáveis por angio TC na árvore coronária, torna-‐se importante desenvolver ferramentas que permitam quantificar a carga aterosclerótica e assim identificar os indivíduos que poderão eventualmente beneficiar de medidas de prevenção mais intensivas. Com este objectivo, foi desenvolvido um índice de carga aterosclerótica que reúne a informação global acerca da localização, do grau de estenose e do tipo de placa, obtida pela angio TC cardíaca, o CT--‐LeSc. Este score poderá vir a ser uma ferramenta útil para quantificação da carga aterosclerótica coronária, sendo de esperar que possa traduzir a informação prognóstica da angio TC cardíaca. Por fim, o conceito de árvore coronária vulnerável poderá ser mais importante do que o da placa vulnerável e a sua identificação pela angio TC cardíaca poderá ser importante numa estratégia de prevenção mais avançada. Esta poderá permitir personalizar as medidas de prevenção primária, doseando melhor a sua intensidade em função da carga aterosclerótica, podendo esta vir a constituir uma das mais importantes indicações da angio TC cardíaca no futuro.---------------- ABSTRACT Despite the significant advances made possible in recent years in the field of pharmacology and diagnostic tests, acute yocardial infarction and sudden cardiac death remain the first manifestation of coronary atherosclerosis in a significant proportion of patients, as many were previously asymptomatic. Traditionally, the diagnostic exams employed for the evaluation of possible coronary artery disease are based on the documentation of myocardial ischemia and, in this way, they are linked to the presence of obstructive coronary stenosis. Nonobstructive coronary lesions are also frequently involved in the development of coronary events. Although the absolute risk of becoming unstable per plaque is higher for more obstructive and higher burden plaques, these are much less frequent than nonobstructive lesions and therefore, in terms of probability for the patient, coronary events are often the result of rupture or erosion of the latter ones. Recent advanced intracoronary imaging studies provided evidence that although it is possible to identify some features of vulnerability in plaques associated with subsequente development of coronary events, the sensitivity and sensibility are very limited for clinical application. More important than the individual risk associated with a certain plaque, for the patient it might be more important the global risk of the total coronary tree, as reflected by the sum of the diferent probabilities of all the lesions, since the higher the coronary Atherosclerotic burden, the higher the risk for the patient. Cardiac CT or Coronary CT angiography is still a young modality. It is the most recente noninvasive imaging modality in the study of coronary artery disease and its development was possible due to important advances in multidetector CT technology. These allowed significant improvements in temporal and spatial resolution, leading to better image quality and also some impressive reductions in radiation dose. At the same time, the increasing experience with this technique lead to a growing body of scientific evidence, making cardiac CT a robust imaging tool for the evaluation of coronary artery disease and increased its clinical indications. More recently, several publications documented its prognostic value, marking the transition of cardiac CT to adulthood. Besides being able to exclude the presence of coronary artery disease and of obstructive lesions, Cardiac CT allows also the identification of nonobstructive lesions, making this a unique tool in the field of noninvasive imaging modalities. By evaluating both obstructive and nonobstructive lesions, cardiac CT can provide for the quantification of total coronary atherosclerotic burden, and this can be useful to stratify the risk of future coronary events. In the present work, it was possible to identify significant demographic and clinical predictors of a high coronary atherosclerotic burden as assessed by cardiac CT, but with modest odds ratios, even when the individual variables were gathered in clinical scores. Among these diferent clinical scores, the performance was better for the Heartscore, a cardiovascular risk score. This modest performance underline the limitations on predicting the presence and severity of coronary disease based only on clinical variables, even when optimized together in risk scores, One of the classical risk factors, obesity, had in fact a paradoxical relation with coronary atherosclerotic burden and might explain some of the limitations of the clinical models. On the opposite, diabetes mellitus was one of the strongest clinical predictors, and was considered to be a model of more advanced coronary disease, useful to evaluate the performance of diferent plaque burden scores. In face of the high prevalence of plaques that can be identified in the coronary tree of patients undergoing cardiac CT, it is of utmost importance to develop tools to quantify the total coronary atherosclerotic burden providing the identification of patients that could eventually benefit from more intensive preventive measures. This was the rational for the development of a coronary atherosclerotic burden score, reflecting the comprehensive information on localization, degree of stenosis and plaque composition provided by cardiac CT – the CT-LeSc. This score may become a useful tool to quantify total coronary atherosclerotic burden and is expected to convey the strong prognostic information of cardiac CT. Lastly, the concept of vulnerable coronary tree might become more important than the concept of the vulnerable plaque and his assessment by cardiac CT Might become important in a more advance primary prevention strategy. This Could lead to a more custom-made primary prevention, tailoring the intensity of preventive measures to the atherosclerotic burden and this might become one of the most important indications of cardiac CT In the near future.

Automatic delimitation of the clinical region of interest in ultra-wide field of view images of the retina

Retinal ultra-wide field of view images (fundus images) provides the visu-alization of a large part of the retina though, artifacts may appear in those images. Eyelashes and eyelids often cover the clinical region of interest and worse, eye-lashes can be mistaken with arteries and/or veins when those images are put through automatic diagnosis or segmentation software creating, in those cases, the appearance of false positives results. Correcting this problem, the first step in the development of qualified auto-matic diseases diagnosis programs can be done and in that way the development of an objective tool to assess diseases eradicating the human error from those processes can also be achieved. In this work the development of a tool that automatically delimitates the clinical region of interest is proposed by retrieving features from the images that will be analyzed by an automatic classifier. This automatic classifier will evaluate the information and will decide which part of the image is of interest and which part contains artifacts. The results were validated by implementing a software in C# language and validated through a statistical analysis. From those results it was confirmed that the methodology presented is capable of detecting artifacts and selecting the clin-ical region of interest in fundus images of the retina.

Immunohistochemical expression of oestrogen and progesterone receptors during experimental acute and chronic murine Schistosomiasis mansoni

INTRODUCTION: The responsibility of Schistosoma mansoni in female infertility is still controversial. This study was conducted to evaluate the effect of acute and chronic schistosomiasis mansoni infection on the endometrium using immunohistochemical analysis of uterine hormone receptor expression. METHODS: Twenty-four nonpregnant swiss albino mice were divided into three groups: control, noninfected; acute; and chronic Schistosoma mansoni infection. Histological sections of uterine specimens were examined by light microscope with an image analyzing system to detect structural histological, estrogen receptor (ER) and progesterone receptor (PR) expression in the endometrium. RESULTS: No secretory phase was detected in the endometrium in acute and chronic Schistosoma infection. Hormone receptor expression (ER and PR) showed statistically significant differences among the groups (p< 0.05), with significant low ER hormone expression in chronic infection, compared to control proliferative, control secretory and acute infection cases, and statistically significant high PR expression in both acute and chronic infection cases compared to the control secretory cases (p< 0.05). CONCLUSIONS: Schistosomiasis mansoni seems to have an important impact on the hormone expression of affected women. Further studies to explore the mechanism of such changes are recommended.

Image processing for displacement measurements

Since the invention of photography humans have been using images to capture, store and analyse the act that they are interested in. With the developments in this field, assisted by better computers, it is possible to use image processing technology as an accurate method of analysis and measurement. Image processing's principal qualities are flexibility, adaptability and the ability to easily and quickly process a large amount of information. Successful examples of applications can be seen in several areas of human life, such as biomedical, industry, surveillance, military and mapping. This is so true that there are several Nobel prizes related to imaging. The accurate measurement of deformations, displacements, strain fields and surface defects are challenging in many material tests in Civil Engineering because traditionally these measurements require complex and expensive equipment, plus time consuming calibration. Image processing can be an inexpensive and effective tool for load displacement measurements. Using an adequate image acquisition system and taking advantage of the computation power of modern computers it is possible to accurately measure very small displacements with high precision. On the market there are already several commercial software packages. However they are commercialized at high cost. In this work block-matching algorithms will be used in order to compare the results from image processing with the data obtained with physical transducers during laboratory load tests. In order to test the proposed solutions several load tests were carried out in partnership with researchers from the Civil Engineering Department at Universidade Nova de Lisboa (UNL).

Métodos de avaliação do impacto económico dos eventos adversos em meio hospitalar

RESUMO - O sistema de saúde é constantemente sujeito a pressões sendo as mais relevantes a pressão para o aumento da qualidade e a necessidade de contenção de custos. Os Eventos Adversos (EAs) ocorridos em meio hospitalar constituem um sério problema de qualidade na prestação de cuidados de saúde, com consequências clinicas, sociais, económicas e de imagem, que afectam pacientes, profissionais, organizações e o próprio sistema de saúde. Os custos associados à ocorrência de EAs em meio hospitalar, incrementam significativamente os custos hospitalares, representando cerca de um em cada sete dólares gastos no atendimento dos doentes. Só na última década surgiram estudos com o objectivo principal de avaliar esse impacto em meio hospitalar, subsistindo ainda uma grande indefinição quanto às variáveis e métodos a utilizar. O objectivo principal deste trabalho de projecto foi conhecer e caracterizar as diferentes metodologias utilizadas para avaliação dos custos económicos, nomeadamente dos custos directos, relacionados com a ocorrência de eventos adversos em meio hospitalar. Tendo em atenção as dificuldades referidas, utilizou-se como metodologia a revisão narrativa da literatura, complementada com a realização de uma técnica de grupo nominal. Os resultados obtidos foram os seguintes: i) a metodologia utilizada na maioria dos estudos para determinar a frequência, natureza e consequências dos EAs ocorridos em meio hospitalar, utiliza matrizes de base observacional, analítica, com base em estudos de coorte retrospectivo recorrendo aos critérios definidos pelo Harvard Medical Practice Study; ii) a generalidade dos estudos realizados avaliam os custos directos dos EAs em meio hospitalar, iii) verificou-se a existência de uma grande diversidade de métodos para a determinação dos custos associados aos EAs. A generalidade dos estudos determina esse valor com base na contabilização do número de dias adicionais de internamento, resultantes do EA, valorizados com base em custos médios; iv) o grupo de peritos, propôs como metodologia para a determinação do custo associado a cada EA, a utilização de sistemas de custeio por doente; v) propõe-se o desenvolvimento de uma plataforma informática, que permita o cruzamento da informação disponível no registo clinico electrónico do doente com um sistema automático de identificação de EAs, a desenvolver, e com sistemas de custeio por doente, de modo a valorizar os custos por doente e por tipo de EA. A avaliação dos custos directos associados à ocorrência de EAs em contexto hospitalar, pelo impacto económico e social que tem nos doentes e organizações, será seguramente uma das áreas de estudo e investigação futuras, no sentido de melhorar a eficiência do sistema de saúde e a qualidade e segurança dos cuidados prestados aos doentes.

Mobile image processing to support educational geometry games

The mobile IT era is here, it is still growing and expanding at a steady rate and, most of all, it is entertaining. Mobile devices are used for entertainment, whether social through the so-called social networks, or private through web browsing, video watching or gaming. Youngsters make heavy use of these devices, and even small children show impressive adaptability and skill. However not much attention is directed towards education, especially in the case of young children. Too much time is usually spent in games which only purpose is to keep children entertained, time that could be put to better use such as developing elementary geometric notions. Taking advantage of this pocket computer scenario, it is proposed an application geared towards small children in the 6 – 9 age group that allows them to consolidate knowledge regarding geometric shapes, forming a stepping stone that leads to some fundamental mathematical knowledge to be exercised later on. To achieve this goal, the application will detect simple geometric shapes like squares, circles and triangles using the device’s camera. The novelty of this application will be a core real-time detection system designed and developed from the ground up for mobile devices, taking into account their characteristic limitations such as reduced processing power, memory and battery. User feedback was be gathered, aggregated and studied to assess the educational factor of the application.

The impact of talent management practices on employee retention: The moderator effect of leader-member exchange and role modeling

Organizations are undergoing serious difficulties to retain talent. Authors argue that Talent Management (TM) practices create beneficial outcomes for individuals and organizations. However, there is no research on the leaders’ role in the functioning of these practices. This study examines how LMX and role modeling influence the impact that TM practices have on employees’ trust in their organizations and retention. The analysis of two questionnaires (Nt1=175; Nt2=107) indicated that TM only reduced turnover intentions, via an increase in trust in the organization, when role modeling was high and not when it was low. Therefore, we can say that leaders are crucial in the TM context, and in sustaining a competitive advantage for organizations.

Development of a fundus camera for analysis of photoreceptor directionality in the healthy retina

The Stiles-Crawford effect (SCE) is the well-known phenomenon in which the brightness of light perceived by the human eye depends upon its entrance point in the pupil. This physiological characteristic is due to the directional sensitivity of the cone photoreceptors in the retina and it displays an approximately Gaussian dependency which is altered in a number of pathologies. Retinal imaging, a widely spread clinical practice, may be used to evaluate the SCE and thus serve as diagnostic tool. Nonetheless, its use for such a purpose is still underdeveloped and far from the clinical reality. In this project a fundus camera was built and used to assess the cone photoreceptor directionality by reflective imaging of the retina in healthy individuals. The physical and physiological implications of its development are addressed in detail in the text: the optical properties of the human eye, illumination issues, acquiring a retinal image formed by the eye, among others. A full description of the developmental process that led to the final measuring method and results is also given. The developed setup was successfully used to obtain high quality images of the eye fundus and in particular the parafoveal cone photoreceptors. The SCE was successfully observed and characterized. Even though considerable improvements could be done to the measurement method, the project showed the feasibility of using retinal imaging to evaluate the SCE thus motivating its usage in a clinical environment.

The impact of online promotional efforts on customer acquisitiom and retention at continente.pt

Continente Online (COL) is the market leader of online grocery retailing in Portugal. Aiming at sustaining this position, it has been focusing its promotional efforts in acquiring and retaining customers. This report intakes an extensive study on the impact of COL’s exclusive promotional efforts (free delivery offers and ten percent discounts on loyalty card) on customer acquisition and retention, as well as, a cost analysis on these offers. Two econometric models were developed and the results were interesting. It was concluded that free delivery offers have a significant impact both in terms of customer acquisition and retention, having also a lower cost in comparison with ten percent on loyalty card discounts.

Urethral catheter removal 7 or 14 days after radical retropubic prostatectomy: clinical implications and complications in a randomized study

PURPOSE: To evaluate the hypothesis that a 7-day period of indwelling catheter after radical retropubic prostatectomy is effective and safe without the need of performing cystography. METHODS: In the period from January of 2000 to July of 2002, 73 patients underwent radical retropubic prostatectomy, and these patients were prospectively randomized in 2 groups: Group 1-37 patients who had the urethral catheter removed 7 days after the procedure, and Group 2-36 patients who had the catheter removed 14 days after the surgery. The 2 groups were similar, the surgeons and the technique were the same, and no cystography was performed to evaluate the presence of leaks. RESULTS: Two patients in Group 1 had bleeding and clot retention after having the catheter taken out in the seventh postoperative day and were managed by putting the catheter back in for 7 more days. Two patients in Group 2 developed bladder neck stricture and were treated by bladder neck incision with success. The continence rate was the same, with 2 cases of incontinence in each group. About 2 pads a day were used by the patients with incontinence. The average follow-up was 17.5 months (12-36 months). No urinary fistula, urinoma, or pelvic abscesses developed after catheter removal. Two patients were excluded from the analysis of this series: 1 died with a pulmonary embolus in the third postoperative day, and 1 developed a urinary suprapubic fistula before catheter withdrawal, which was maintained for 16 days. CONCLUSION: Withdrawal of the urethral catheter 7 days after radical retropubic prostatectomy, without performing cystography, has a low rate of short-term complications that are equivalent to withdrawal 14 days after the surgery.