O presente estudo objetivou a caracterização hidrogeoquímica ao longo da bacia de drenagem do rio Sorocaba - São Paulo, em cinco estações de amostragens, localizadas desde a região de nascentes, estação S5- Ibiúna, passando por áreas com maior influencia urbana e agrícola (S4 - Votarantim, S3 - Itavuvu e S2 - Tatuí), até a foz da bacia em estudo, S1 - Laranjal Paulista, utilizando-se modelos de transporte de materiais nas fases dissolvidas e particuladas. Para tal, foram realizadas coletas ao longo de 18 meses, de amostras de águas fluviais, pluviais, sedimento fino em suspensão (FSS) e dos principais tipos solos integrantes da bacia. Importantes parâmetros físico-quimicos e a caracterização das cargas dissolvida e particulada foram determinados. As características hidroquímicas das águas fluviais mostraram que as espécies químicas SiO2, Ca2+, Mg2+, K+, HCO3- e TDS indicaram possíveis aportes difusos e as espécies Na+, Cl-, SO42-, PO43-, NH4+ e NO3-indicaram origens pontuais. O elemento químico dissolvido que mais contribuiu no transporte específico fluvial junto à foz do rio Sorocaba (S1- Laranjal Paulista), foi o Na+ para os cátions (24,25, kg km-2 d-1) e para os ânions foi o HCO3- com 53,97 kg km-2 d-1. Já no transporte pluvial o Ca2+ foi a espécie química que apresentou maior contribuição na carga do rio com 54,89 %. Com relação ao material particulado, representada pelo FSS, o transporte específico variou de 22,68 a 55,70 t km-2 a-1, desde a região das nascentes até a foz, respectivamente. O rio Sorocaba foi classificado como médio transportador de sedimento fino em suspensão e a erosão mecânica foi de 37,88 m.Ma-1 / This study aimed to characterize the hydrogeochemical along the Sorocaba river basin (SP), in five sampling stations, located from the headwaters region, S5-Ibiúna station, passing through areas with higher urban and agricultural influences (S4 - Votorantim, S3 - Itavuvu and S2 and Tatuí, to the mouth of the basin under study, S1 - Laranjal Paulista, using models of transport on dissolved and particulate phases. Samples of river water, pluvial, fine suspended sediment (FSS) and the main soils types were collected over 18 months. Important physico-chemical characterization of dissolved and particulate loads were determined. The hydrochemical features of the river water showed that the chemical species SiO2, Ca2 +, Mg2+, K +, HCO3-and TDS indicated possible diffuse contributions and species Na +, Cl-, SO42-, PO43-, NH4+ and NO3-indicated origin contributions. The dissolved chemical element who more contributed in transport dissolved specific in S1-Laranjal Paulista), was Na+ for cations, with 24,25 kg km-2 d-1 and for anions was HCO3- with 53.97 kg km-2 d-1. In the rain Ca2+ was the chemical species with the highest contribution to the river load with 54.89%. The suspended particulate matter, represented by the FSS, the specific transport ranged from 22.68 to 55.70 t km-2 a-1, from the region of the headwaters to the mouth, respectively. The river was classified as medium transporting fine sediment in suspension and the mechanical erosion was the 37.88 m .Ma-1

by Kwok Lai Ho Victor. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 77-82). / Abstract also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background --- p.5 / Chapter 2.1 --- History of Robotics --- p.5 / Chapter 2.2 --- Autonomous Robot Systems --- p.7 / Chapter 2.3 --- 3D Windowing Simulators --- p.8 / Chapter 2.4 --- Robot Simulation in VR --- p.8 / Chapter 3 --- Objective --- p.11 / Chapter 4 --- Articulated Structures --- p.13 / Chapter 4.1 --- Joints and links --- p.13 / Chapter 4.2 --- Degrees of Freedom --- p.16 / Chapter 4.3 --- Denavit-Hartenberg Notation --- p.17 / Chapter 5 --- Virtual Manipulators --- p.20 / Chapter 5.1 --- Arm(N-link) Structure --- p.20 / Chapter 5.2 --- Hand Model --- p.24 / Chapter 6 --- Motion Control Techniques --- p.27 / Chapter 6.1 --- Kinematics --- p.27 / Chapter 6.1.1 --- Forward Kinematics --- p.27 / Chapter 6.1.2 --- Inverse Kinematics --- p.29 / Chapter 6.1.3 --- Solving Kinematics Problem --- p.29 / Chapter 6.1.4 --- Redundancy --- p.31 / Chapter 6.1.5 --- Singularities --- p.32 / Chapter 6.2 --- Dynamics --- p.33 / Chapter 6.2.1 --- Forward Dynamics --- p.34 / Chapter 6.2.2 --- Inverse Dynamics --- p.35 / Chapter 6.3 --- Combination of Two Control Modes --- p.35 / Chapter 6.4 --- Constraints and Optimization --- p.36 / Chapter 7 --- Physical Feedback Systems --- p.38 / Chapter 7.1 --- Touch Feedback --- p.39 / Chapter 7.2 --- Force Feedback --- p.41 / Chapter 7.3 --- Force/Touch Feedback Systems --- p.42 / Chapter 8 --- Virtual Object Manipulation --- p.43 / Chapter 8.1 --- Previous Work --- p.44 / Chapter 8.2 --- Physics-based Virtual-hand Grasping --- p.45 / Chapter 8.3 --- Visual Correction --- p.43 / Chapter 8.3.1 --- Joint Correction --- p.50 / Chapter 8.3.2 --- Odd Finger Configurations --- p.51 / Chapter 8.4 --- Active Grasping --- p.52 / Chapter 8.5 --- Collision Detection of Complex Objects --- p.54 / Chapter 9 --- Experiments --- p.57 / Chapter 9.1 --- System Architecture --- p.57 / Chapter 9.1.1 --- Tracking System --- p.53 / Chapter 9.1.2 --- Glove System --- p.59 / Chapter 9.1.3 --- Host Computer --- p.60 / Chapter 9.2 --- Experimental Results --- p.60 / Chapter 9.2.1 --- General application --- p.61 / Chapter 9.2.2 --- Relationship between frictional coefficient and mass of the object --- p.61 / Chapter 10 --- Conclusions --- p.67 / Chapter 10.1 --- Summary --- p.67 / Chapter 10.2 --- Contributions --- p.69 / Chapter 10.3 --- Future Work --- p.69 / Chapter A --- Description files --- p.71 / Chapter A.1 --- Scene Description --- p.71 / Chapter A.2 --- Hand Description --- p.73 / Bibliography --- p.77

This dissertation addresses the effect of information on firm and individual behavior. The first chapter examines the design of an optimal feedback mechanism by an informed principal and uses the results to explain why firms tend to assign coarse subjective ratings to their employees. When a firm has private information about an employee's ability, it can communicate this information through a subjective evaluation mechanism. I characterize the firm's optimal disclosure policy as a function of the worker's ability distribution and provide an algorithm to compute it. Further, I show that with some reasonable restrictions on the ability distribution, the firm's optimal strategy is always to reward the best workers, fire the worst ones, and assign one central rating to the rest. The second chapter investigates an informed principal's optimal feedback strategy in a dynamic setting. I first consider the case where both parties have non-binding outside options. In this case, if the principal ever wants to reveal any information, she will do so at the earliest possible stage. Moreover, the optimal disclosure policy can be characterized in the same way as in the static case. The same conclusion holds for the case where both parties have binding and constant outside options. I also discuss the case where both parties have binding and time-variant outside options. After incorporating firms' need to promote and/or to retain workers, the model is used to explain wage dynamics. The third chapter models a decision maker who "rationally" distorts his own belief to avoid the feeling of regret. People often suffer from regret when they realize that their previous choices were suboptimal. As a result, in a dynamic setting where information is revealed gradually, people are tempted to deny new negative information in order to avoid regret. At the same time, they are also aware of the economic cost of such belief distortions. A "rational" decision maker will optimally trade off these two concerns and choose his own belief accordingly. This tradeoff makes the past affect current decisions and hence can explain the sunk cost fallacy.

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Includes bibliographical references. / M.S.

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Bibliography: leaves 216-220. / Ph.D.

Accurate identification of small-molecule compound substrates and effectors, within specific tissues, represents a highly relevant yet equally elusive objective. Accomplishing this goal would have major implications on the assessment of compound efficacy and potential toxicity with significant impact on drug discovery and development. Computationally, there are no methods to elucidate a compound mechanisms of action (MoA) in cell-context-specific and genome-wide fashions. Experimental approaches are equally limited in that they are effective in identifying only specific drug substrate classes (e.g., high-affinity substrates of kinase inhibitors) rather than the full repertoire of proteins that effect compound activity in a specific tissue, including those that may cause undesired toxicity. They are costly, laborious, and the relevant mechanistic assays can only be performed in vitro. Here I introduce DeMAND, a novel algorithm for the regulatory network-based elucidation of compound Mechanisms of Action. The algorithm interrogates a context-specific regulatory network using at least six gene-expression profiles representative of in vitro or in vivo compound perturbation to identify compound dysregulated sub-networks as well as substrates and effector proteins. In experimental tests, the algorithm correctly identified proteins in the established MoA of over 90% of the tested compounds, including protein such as SIK1, a private effector of doxorubicin responsible for its cardiac toxicity, which is however not affected by less toxic topoisomerase inhibitors, such as camptothecin. Using gene expression profiles following perturbation of diffuse large B cell lymphoma cells with 14 and 92 compounds, respectively, at different concentrations and time points, I identified and validated several novel effector proteins. These include RPS3A (ribosomal protein S3A), VHL (von Hippel-Lindau tumor suppressor, E3 ubiquitin protein ligase), and CCNB1 (cyclin B1) as effectors of the mitotic spindle inhibitor vincristine, all of which significantly affected microtubule architecture and/or modulated vincristine activity when silenced, as well as JAK2 (Janus kinase 2) as a novel effector/modulator of mitomycin C, which desensitizes cells to mitomycin C treatment when silenced. Finally, I used DeMAND to evaluate compound similarity by comparing the proteins in their MoA. I tested the similarity of altretamine, a compound with currently unknown substrates, and sulfasalazine, which were predicted to have similar MoA and in particular to be inhibitors of the GPX4 (glutathione peroxidase 4) protein. Experimental validation confirmed this prediction as well as increase in lipid reactive oxygen species (ROS) levels, a recently established downstream effector of sulfasalazine. Critically, DeMAND suggests that regulatory networks reverse engineered de novo form large molecular profile datasets can provide novel mechanistic insight into drug activity, thus providing a significant novel contribution to our search for highly specific and non-toxic small-molecule inhibitors.

Phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3)-dependent RAC exchanger 2 (PREX2) is a guanine nucleotide exchange factor (GEF) for the Ras-related C3 botulinum toxin substrate 1 (RAC1) GTPase. As a GEF, PREX2 facilitates the exchange of GDP for GTP on RAC1. GTP bound RAC1 then activates its downstream effectors, including p21-activated kinases (PAK). PREX2, RAC1, and PAK kinases all have key roles within the insulin signaling pathway. The insulin receptor is a tyrosine kinase that phosphorylates the insulin receptor substrate (IRS) family of adaptor proteins, leading to the activation of phosphatidylinositide 3-kinase (PI3K) and the generation of PI(3,4,5)P3. PI(3,4,5)P3 then activates numerous downstream signaling proteins, including AKT and RAC1, to regulate several important cellular processes, such as glucose metabolism and cell proliferation. In addition to being a RAC1 GEF, PREX2 affects the insulin signaling pathway by inhibiting the lipid phosphatase activity of phosphatase and tensin homolog (PTEN), which dephosphorylates PI(3,4,5)P3 to antagonize PI3K. PREX2 is also important in cancer, which is likely a consequence of both its role as a RAC1 GEF and as a PTEN inhibitor. PREX2 GEF activity is activated by PI(3,4,5)P3 and by Gβγ, which is a heterodimer that is released after GPCR activation. However, PREX2 regulation within specific signaling pathways is poorly understood. This thesis aims to understand the regulation of PREX2 downstream of ligand binding to receptors on the cell surface, with a focus on insulin. This is achieved by studying the phosphorylation of PREX2 after insulin stimulation and by characterizing protein-protein interactions involving PREX2 and key proteins in the insulin signaling pathway. Herein, we identified PI(3,4,5)P3-dependent phosphorylation events on PREX2 that occur downstream of insulin stimulation. Phosphorylation of PREX2 also occurred downstream of Gβγ, suggesting that phosphorylation was associated with the activation of PREX2 GEF activity. Interestingly, phosphorylation of PREX2 reduced GEF activity towards RAC1 and a phospho-mimicking mutation of PREX2 at an insulin-mediated phosphorylation site reduced cancer cell invasion. Phosphorylation of PREX2 also decreased PREX2 binding to the cellular membrane, PI(3,4,5)P3, and Gβγ, providing a mechanism for reduced GEF activity. These data suggested that phosphorylation was part of a negative feedback circuit to decrease the RAC1 signal, which led to the identification of the PAK kinases as mediators of PREX2 phosphorylation. Importantly, insulin-induced phosphorylation of PREX2 was delayed compared to AKT, which is consistent with a model where PREX2 phosphorylation by PAK occurs after activation of PREX2 to attenuate its function. Altogether, we propose that second messengers activate the PREX2-RAC1 signal, which sets in motion a cascade whereby PAK kinases phosphorylate and negatively regulate PREX2 to decrease RAC1 activation. This type of regulation would allow for transient activation of the PREX2-RAC1 signal. We then asked whether PAK phosphorylation of PREX2 was altered in cancer. To do this, we analyzed four recurrent somatic PREX2 tumor mutations, R155W, R297C, R299Q, and R363Q. Interestingly, all four mutants had reduced insulin and PAK1 dependent phosphorylation, and R297C had lower levels of phosphorylation induced by PI3K activating tumor mutants. This suggests that tumors might be mutating PREX2 in order to avoid PAK mediated negative regulation of RAC1. Lastly, we characterized PREX2 interactions with proteins that are critical for insulin signaling, with a focus on the interaction between the PREX2 pleckstrin homology (PH) domain and PTEN. PREX2 inhibition of PTEN is mediated by the PH domain, and we discovered that the β3β4 loop of the PH domain was required for binding of the isolated PH domain to PTEN. We also found that PREX2 co-immunoprecipitates with other insulin related proteins, including the p85 regulatory subunit of PI3K, IRS4, and the insulin receptor. Taken together, the studies in this thesis solidify the role of PREX2 in insulin signaling by showing that PREX2 GEF activity is tightly regulated by insulin and PAK-induced phosphorylation and also by characterizing PREX2 interactions with critical insulin related proteins. Further, this PAK dependent negative regulatory circuit downstream of both PI(3,4,5)P3 and Gβγ activation of PREX2 could have impacts in many aspects of biology given the roles that PREX2 and RAC1 have in critical cellular functions such as cell motility and glucose metabolism, and in diseases such as cancer and diabetes.

Os mecanismos amplamente utilizados em aplicações industriais são de tipo serial, porém há algum tempo vem sendo desenvolvidos estudos sobre as vantagens que os mecanismos de arquitetura paralela oferecem em contraposição com os seriais. Rigidez, precisão, altas frequências naturais e velocidade são algumas características que os mecanismos paralelos atribuem a máquinas já consolidadas na indústria, destinadas principalmente nas operações de manipulação (pick and place). Nesse sentido, é relevante o estudo sobre a funcionalidade em outros tipos de operação como a usinagem e, particularmente o fresamento. Para isto, devem-se ainda explorar e desenvolver as capacidades dos mecanismos paralelos em relação à rigidez e à precisão nas operações mencionadas. Foi desenvolvido previamente o projeto e montagem do protótipo de uma máquina fresadora de arquitetura paralela. Também aracterizado pela redundância na atuação para o posicionamento da ferramenta. Com este intuito, pretende-se no trabalho atual, avaliar o erro estático de posicionamento da ferramenta por métodos experimentais, quantificar os deslocamentos, realizar um mapeamento experimental em diversas configurações dos membros. Por outro lado, pretende-se adaptar um modelo numérico simplificado que possa prever as deformações elásticas em diversas configurações, que contemple o efeito de juntas lineares flexíveis e que de alguma forma ajude a identificar as principais fontes de erro. Para tal, foram elaboradas rotinas de programação que através da cinemática inversa e o uso do método dos elementos finitos tentem prever o que de fato acontece nos experimentos. Foi proposta também uma implementação alternativa para o controle do mecanismo através de um software CNC e a conversão de coordenadas cartesianas em coordenadas dos atuadores, isto ajudaria na geração do código G. Finalmente, foram elaboradas algumas trajetórias que tentam avaliar a exatidão e repetitividade do mecanismo além de descrever outras trajetórias livres. / Serial mechanisms have been widely used in industrial applications, on the other hand some studies related to advantages of parallel kinematics and its benefits have been developed in the last decades. Stiffness, accuracy, high natural frequencies and velocities are some characteristics that this kind of kinematic architecture attribute to some industrial machines specially used in \"pick and place\" operations. However, it remains relevant to study the functionality that parallel mechanisms could offer in other kind of applications such as milling. In order to achieve this, it is important to evaluate and explore the capabilities and performance characteristics when precision and stiffness are involved. A milling machine with parallel architecture prototype has been designed and constructed in previous works. The tool positioning is characterized by redundant actuation. The present work aims to evaluate the static error of the tool positioning mechanism by experimental procedures, in order to quantify the tool displacements under some established loads and to elaborate an experimental map for static error in different mechanism configurations. On the other hand, it is intended to adapt a simplified numerical model that could predict the stiffness behavior along the workspace including the effect of flexible linear actuators. For this purpose, a finite element method script was developed to solve all the structure displacements. In addition, it was proposed an alternative control implementation that works through an open source CNC software and its appropriate kinematic conversion for the mechanism characteristics and the generation of G Code scripts. Finally, some trajectories were planned in order to evaluate accuracy and repeatability in two proposed paths besides some other free operations.

Carbon forestry projects have proliferated over last few years on the premise of cost efficient climate mitigation along with co-benefits of biodiversity conservation and livelihood improvement. Multilateral, bilateral, public and private sources have invested billions of dollars in the carbon forestry projects based on these claims. However, there is little empirical evidence to support the enthusiasm. This gap is further accentuated by the insufficient understanding of the governance challenges of these projects. These issues are social, political and ecological in nature and hence require a multidisciplinary political ecology framework for a comprehensive analysis. This thesis explores the multiple benefit claims and governance issues by analysing two forestry-based Clean Development Mechanism projects from India. One, in Haryana state focuses on private lands, the other in Himachal involves three different types of lands viz. community, public and private for plantation activities. This thesis examines the carbon, biodiversity and livelihood benefits of each project, and the governance challenges associated with them. I show that both projects have sequestered substantially less carbon than was originally predicted, which has serious implications for carbon revenues and hence economic viability of these projects. In the case of biodiversity, the results are mixed. In Haryana, the tree and herb biodiversity has improved in the project plots as compared to control plots, whereas shrub biodiversity has marginally declined. In case of Himachal project, biodiversity has declined at tree, shrub and herb levels. I have analysed livelihood impacts in terms of foregone crop, fodder and fuel wood benefits across small, medium and large category of farmers. Both the projects have adverse livelihood impacts on the participants, more so in Haryana because of the plantations on private lands. Although the project has adversely affected the livelihoods of all three categories of farmers, however it has affected small farmers the most due to their low incomes and risk-bearing capacities. Hence, these projects have serious equity implications. This thesis also explores the governance challenges of carbon forestry in terms of their interaction with existing policy mechanisms, especially the Forest Rights Act of 2006, which recognises the ownership and use rights of forest dependent communities comprehensively first time in independent India. The analysis suggests that there are various issues that carbon forestry projects pose for the implementation of the Act due to which civil society groups are opposing these projects. This thesis contributes to our understanding of the multiple benefit claims of carbon forestry projects with empirical evidence and a political ecological analysis. It shows that there is possibility of tradeoffs and many other scenarios in carbon forestry projects rather than just the projected 'win-win-win' outcomes. It contributes to the political economy literature by establishing that changes in global commodity markets can influence land use choices at local level, affecting the sustainability of such efforts. This thesis also advances the literature on governance of carbon forestry projects by reflecting on various policy and implementation level issues related to property rights, community institutions, transparency and accountability.

A partir d’un réseau d’établissements et par une approche qualitative et quantitative : un lycée, un collège, une école primaire et deux collèges supplémentaires, l’étude s’intéresse aux transgressions scolaires au filtre du genre des élèves et des personnels éducatifs. De précédents travaux affirment que les transgressions sont différentes, ainsi que l’application du système punitif en fonction du sexe des élèves. Ce travail cherche à mettre en évidence les différents facteurs qui participent au mécanisme genré de la transgression scolaire. Il s’articule avec les constructions des identités de la transgression, les manifestations dans l’espace scolaire, les justifications que donnent les individus par rapport à une transgression et les répercussions de cette dernière. Tout permet d’alimenter ce cercle vicieux qui consacre les filles comme étant des élèves modèles, adaptées aux normes du système éducatif et les garçons, comme des individus naturellement transgressifs. Construits et consolidés au moyen des résultats et de la revue de littérature, ces facteurs laissent pressentir un modèle pouvant expliquer et justifier un mécanisme immuable, incessant, perpétuel mais surtout discriminant les élèves filles et garçons qui enfreignent lois, règles et normes dans les établissements scolaires. / Using a network of institutions and both a qualitative and quantitative approach: a high school, asecondary school, a primary school and two additional secondary schools, the study focuses on school transgression through the filter of the pupils and educational staffs’ gender. Previous works assert that these transgressions are different, and thus that the enforcement of the punishment system according to the pupils’ gender is too.Our work attempts to highlight the various factors participating in the gender-based mechanism of school transgression. It is built on the identity construction of the transgression, its manifestations in school, the justifications given by individuals regarding a transgression and the repercussions of the latter. This allows the perpetuation of a vicious circle that sees girls as model pupils, adapted to the standards of the education system, while boys are seen as being naturally transgressive individuals. Built and strengthened by results and literary reviews, these factors allow us to anticipate a model explaining and justifying an unchanging, ceaseless, and perpetual mechanism, but also a model that discriminates between girl and boy pupils who break laws, rules and standards within schools.