496 resultados para Rotatory Inertia
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Introdução: Com uma consciencialização cada vez maior das populações para a preservação dos dentes naturais, a Endodontia tem assumido uma importância crescente, tendo por objectivo principal a manutenção de dentes funcionais, sem prejudicar a saúde dos pacientes. Estes devem beneficiar de um tratamento segundo o “standard of care”, proporcionado por profissionais competentes. Vários estudos demonstram que a Endodontia é considerada uma área difícil e stressante para os estudantes, exibindo um sentimento de menor confiança na prática clínica, sobretudo no que diz respeito a procedimentos mais complexos, nomeadamente, no tratamento de dentes posteriores. Em 2010, na tentativa de homogeneizar as competências adquiridas pelos Médicos Dentistas (MD), a Associação para a Educação Dentária Europeia (AEDE) definiu critérios para a sua formação pré-graduada, indicando que o MD recém-graduado deve ter adquirido competências e capacidades técnicas que lhe permita começar a sua prática clínica de forma independente. Objectivos: Analisar os conhecimentos adquiridos e as dificuldades sentidas na área da Endodontia pelos alunos do 4º e 5º anos do Mestrado Integrado em Medicina Dentária da Faculdade de Ciências de Saúde (FCS) da Universidade Fernando Pessoa (UFP), fazendo, igualmente, uma abordagem ao ensino ministrado na área da Endodontia face aos resultados obtidos. Materiais e Métodos: Este trabalho está dividido em duas partes: revisão bibliográfica e investigação científica. A revisão bibliográfica do tema engloba o ensino graduado em Medicina Dentária, o uso de isolamento absoluto (IA) na prática clínica de Endodontia, a instrumentação manual versus rotatória, a influência no sucesso do tratamento endodôntico (TE) da sua execução por estudantes do 4º e 5º ano, as Guidelines para o TE e o ensino de Endodontia na UFP. A pesquisa bibliográfica foi efectuada através da base de dados PubMed, tendo sido utilizadas, em diferentes combinações, as seguintes palavras-chave: ”Endodontics”, “teaching”; “pre-clinical”; “undergraduate”; “Clinical”; “treatment” e “Europe”. O trabalho de investigação consistiu na elaboração, aprovação pela Comissão de Ética da UFP e posterior aplicação de um questionário destinado aos alunos do 4º e 5º ano do Mestrado Integrado em Medicina Dentária da FCS-UFP. A população estimada de alunos do 4º ano foi de 190 alunos e a de 5º ano de 150 alunos, o que perfaz um total de 340 alunos. Dos inquéritos respondidos, apenas foram considerados 338, uma vez que dois foram anulados pois continham respostas inválidas. Resultados: A “condição socioeconómica do paciente” foi considerada a causa menos relevante para avaliar um caso endodôntico, tendo sido apontada por 34,3% dos alunos. Assinala-se que 92% dos alunos de 4º ano e 93,3% dos alunos de 5º ano consideram que os molares superiores são os dentes mais difíceis de tratar, sendo a visibilidade uma das principais razões para esta opinião. O grau de dificuldade para a colocação do IA é definido como “Elevado” para a maioria dos alunos de 4º ano. A maior parte dos alunos de 5º ano considera que o grau de dificuldade para a “Determinação do tipo de reconstrução/prótese fixa mais indicada” é “Elevado”. O passo do TE onde os alunos do 4º ano se sentem mais confiantes é no “Diagnóstico de cárie”, sendo que os alunos do 5º ano se sentem mais confiantes ao realizar o “TE em dentes com 1 ou 2 canais”. O “Conteúdo leccionado nas aulas teóricas” foi considerado o principal aspecto positivo do ensino endodôntico. Por outro lado, o “Número de actos clínicos realizados” foi considerado o principal aspecto negativo, tanto para alunos de 4º como de 5º ano. Em ambos os anos, os principais pontos que os alunos acham que devem ser melhorados são o “Número de pacientes nas aulas clínicas” e a “Aprendizagem da técnica de instrumentação mecanizada/obturação termoplástica”. As principais preocupações referidas, tanto por alunos de 4º como de 5º anos, foram a “Insegurança na prática clínica” e a “Dificuldade em encontrar ofertas profissionais”. Relativamente à qualidade dos seus TE existe um número significativo de alunos do 5º ano que já se auto-avaliam como “Bons” (33,6%), por comparação com os do 4º ano (21,2%), sendo a auto-avaliação de “Razoável” dominante em ambos os anos de formação. Conclusões: Conclui-se que na disciplina de Endodontia na FCS-UFP, são seguidas as Guidelines da European Society of Endodontology (ESE), sendo que estas indicam o protocolo mais correcto a seguir durante o Tratamento Endodôntico Não-Cirúrgico (TENC). Contudo, o reduzido número de actos clínicos e a consequente falta de prática faz com que os alunos se sintam pouco confiantes ao iniciar a sua actividade profissional.
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Standardization and sustainability: these two apparently antagonistic words find the challenge of uniting in a flexible architectonic proposal. This was the idea that motivated the proposal of this assignment, whose appearing is bound up with the necessity of thinking about standardized spaces that attend on functional criterias and environmental sustainability, in reply to an existing real demand. The assignment consists of an architectonic proposal for a flexible standard of a Basic Unit of Health for the bioclimatic zone 7 of RN (UBS RN-7), with emphasis in the environmental sustainability. The project contemplates innumerable involved variables, such as: obedience to the current law of the Health Ministry for the UBSs; formal/aesthetic aspects; criterias of expansiveness of the UBS I for the UBS II; relative aspects to the constructive rationality and, mainly, sustainability aspects. With the intention to unite the variables and, also, glimpsing a proposal that could reach a good functional performance, aesthetic, of environment comfort and energetic efficiency, it was also necessary to consider concepts about the flexibility of the envelopment. The elaboration of the architecture first draft was based on bibliographical research, conceptual studies and references, elaboration of the architectonic program and the draft development for the UBS port I and the UBS port II. To the end, an implantation data sheet for the project is proposed for the UBS standard project, where strategies of thermal isolation, shadowing and thermal inertia are adopted and combined to three possible types of lot, resulting in 24 possibilities of implantation
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To evaluate how individuals at different stages of infection with HIV perceive their health status and its association with mood states. With the introduction of Highly Active Antiretroviral Therapy in 1996, the quality of life of people living with HIV has improved. However, the literature emphasises the negative effects of the disease on the mental health of individuals suffering from this condition and the high incidence of depression among infected individuals. Although people diagnosed and living with HIV are overwhelmed by emotions, we found that various emotional manifestations are understudied within this group of patients. A cross-sectional study was conducted in an outpatient unit of a University Hospital (antiretroviral therapy clinic), with a consecutive sample composed of 152 patients. Data were collected through a questionnaire used to assess the sociodemographic and clinical characteristics, the Short Form (36) Health Survey, and the Profile of Mood States scale. The health status negatively affects the role at the emotional and mental health dimensions. The participants showing a worse health condition than in the previous year had higher levels of tension/anxiety, depression/dejection, fatigue/inertia and confusion/bewilderment. The stage of disease and the profile of mood state emerged as independent phenomena. The results of this study indicate that nurses worldwide should be aware of the emotional aspects (negative emotions strongly impact health) related to the subjective perception of a worsening health status, regardless of the stage of the disease.
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The issue of sustainability is at the top of the political and societal agenda, being considered of extreme importance and urgency. Human individual action impacts the environment both locally (e.g., local air/water quality, noise disturbance) and globally (e.g., climate change, resource use). Urban environments represent a crucial example, with an increasing realization that the most effective way of producing a change is involving the citizens themselves in monitoring campaigns (a citizen science bottom-up approach). This is possible by developing novel technologies and IT infrastructures enabling large citizen participation. Here, in the wider framework of one of the first such projects, we show results from an international competition where citizens were involved in mobile air pollution monitoring using low cost sensing devices, combined with a web-based game to monitor perceived levels of pollution. Measures of shift in perceptions over the course of the campaign are provided, together with insights into participatory patterns emerging from this study. Interesting effects related to inertia and to direct involvement in measurement activities rather than indirect information exposure are also highlighted, indicating that direct involvement can enhance learning and environmental awareness. In the future, this could result in better adoption of policies towards decreasing pollution.
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Introdução: Em Portugal a realidade actual, clínica e financeira do exercício da Medicina Dentária é bem distinta da do final do séc. XX devido à pletora de Médicos Dentistas e à baixa de honorários por acto Médico registada nos últimos anos. Objectivos: Este trabalho teve como objectivo perceber um pouco sobre os detalhes a ter em consideração aquando da abertura de uma clínica centrada na realização de tratamentos na área da Endodontia, e como publicitá-la de forma legal e apelativa. Pretende-se depois também estimar o custo mínimo para a realização de tratamentos Endodonticos com diferentes equipamentos e comparar a eficácia entre tratamentos usando ferramentas diferentes. Materiais e Métodos: Foram usadas como fontes de pesquisa para o presente trabalho bases de dados como a PubMed, B-On e Cochrane Library. Foi também usado o Google. Para pesquisa no PubMed foram usados vários descritores MeSH, como “Commerce”, “Dentistry”, “Endodontics”, “Management” e “Marketing”. Foram também usadas diversas palavras-chave no PubMed e nos outros motores de pesquisa, como “Anesthesia”, “Dental Office”, “Files”, “Irrigation”, “Magnification”, “Microscope”, “Obturation Systems” e “Rotatory Systems”. As pesquisas foram filtradas para serem apresentados apenas resultados entre 2011 e 2016, sendo este filtro retirado só quando não eram encontrados resultados satisfatórios ou relevantes para os temas discutidos no trabalho. Foram obtidos 3927 artigos e seleccionados 24. A inclusão destes artigos foi feita tendo em conta as suas fontes bibliográficas e a qualidade dos estudos a que se reportavam. Foram excluídos artigos que se reportavam a estudos muito antigos ou a tecnologias ultrapassadas, como sistemas de limas antigos. Conclusões: As novas tecnologias usadas para tratamento Endodontico, apesar de dispendiosas, melhoram muito o atendimento ao paciente.
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This thesis looks at how ‘community archaeology’ ideals may influence an inclusive approach to Indigenous heritage management, ensuring Indigenous community power over processes to identify both past and present values of Country. Community archaeology was acclaimed by research archaeologists over a decade ago as a distinctive approach with its own set of practices to incorporate the local community’s perspectives of its past and current associations with place. A core feature of this approach in Australia is the major role the Indigenous community has in decisions about its heritage. Concurrently, considerable concern was being expressed that Indigenous heritage was not sufficiently addressed in environmental impact assessment processes ahead of development. Seen as absent from the process was the inclusion of Indigenous knowledge about both the pre- and post-contact story as well as any scientific advance in understanding an area’s Indigenous history. This research examines these contrasting perspectives seeking to understand the ideals of community archaeology and its potential to value all aspects of Indigenous heritage and so benefit the relevant community. The ideals of community archaeology build on past community collaborations in Australia and also respond to more recent societal recognition of Indigenous rights, reflected in more ethically inclusive planning and heritage statutes. Indigenous communities expressed the view that current systems are still not meeting these policy commitments to give them control over their heritage. This research has examined the on-the-ground reality of heritage work on the outskirts of Canberra and Melbourne. The case studies compare Victorian and ACT heritage management processes across community partnerships with public land managers, and examine how pre-development surveys operate. I conclude that considerable potential for achieving community archaeology ideals exists, and that they are occasionally partially realised, however barriers continue. In essence, the archaeological model persists despite a community archaeology approach requiring a wider set of skills to ensure a comprehensive engagement with an Indigenous community. Other obstacles in the current Indigenous heritage management system include a lack of knowledge and communication about national standards for heritage processes in government agencies and heritage consultants; the administrative framework that can result in inertia or silos between relevant agencies; and funding timeframes that limit possibilities for long-term strategic programs for early identification and management planning for Indigenous heritage. Also, Indigenous communities have varying levels of authority to speak for how their heritage should be managed, yet may not have the resources to do so. This thesis suggests ways to breach these barriers to achieve more inclusive Indigenous heritage management based on community archaeology principles. Policies for a greater acknowledgement of the Indigenous community’s authority to speak for Country; processes that enable and early and comprehensive ‘mapping’ of Country, and long-term resourcing of communities, may have been promised before. In this research I suggest ways to realise such goals.
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Simulations of droplet dispersion behind cylinder wakes and downstream of icing tunnel spray bars were conducted. In both cases, a range of droplet sizes were investigated numerically with a Lagrangian particle trajectory approach while the turbulent air flow was investigated with a hybrid Reynolds-Averaged Navier-Stokes/Large-Eddy Simulations approach scheme. In the first study, droplets were injected downstream of a cylinder at sub-critical conditions (i.e. with laminar boundary layer separation). A stochastic continuous random walk (CRW) turbulence model was used to capture the effects of sub-grid turbulence. Small inertia droplets (characterized by small Stokes numbers) were affected by both the large-scale and small-scale vortex structures and closely followed the air flow, while exhibiting a dispersion consistent with that of a scalar flow field. Droplets with intermediate Stokes numbers were centrifuged by the vortices to the outer edges of the wake, yielding an increased dispersion. Large Stokes number droplets were found to be less responsive to the vortex structures and exhibited the least dispersion. Particle concentration was also correlated with vorticity distribution which yielded preferential bias effects as a function of different particle sizes. This trend was qualitatively similar to results seen in homogenous isotropic turbulence, though the influence of particle inertia was less pronounced for the cylinder wake case. A similar study was completed for droplet dispersion within the Icing Research Tunnel (IRT) at the NASA Glenn Research Center, where it is important to obtain a nearly uniform liquid water content (LWC) distribution in the test section (to recreate atmospheric icing conditions).. For this goal, droplets are diffused by the mean and turbulent flow generated from the nozzle air jets, from the upstream spray bars, and from the vertical strut wakes. To understand the influence of these three components, a set of simulations was conducted with a sequential inclusion of these components. Firstly, a jet in an otherwise quiescent airflow was simulated to capture the impact of the air jet on flow turbulence and droplet distribution, and the predictions compared well with experimental results. The effects of the spray bar wake and vertical strut wake were then included with two more simulation conditions, for which it was found that the air jets were the primary driving force for droplet dispersion, i.e. that the spray bar and vertical strut wake effects were secondary.
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The insertion of distributed generation units in the electric power systems have contributed to the popularization of microgrid concepts. With the microgrids, several potential benefits can be achieved in regard to power quality and supply reliability. However, several technical challenges related to the control and operation of microgrids, which are associated with high insertion of generation systems based on static converters, must be overcame. Among the opportunities in the context of microgrids, there is the islanded operation of microgrids temporarily disconnected from the electric power systems and also the autonomous operation of geographically isolated microgrids. The frequency in large power systems is traditionally controlled by the generation units based on traditional synchronous generator. The insertion of distributed generation units based on static power converters may bring difficulties to the frequency control in microgrids, due to the reduction of the equivalent inertia of conventional synchronous generators present in islanded and isolated microgrids. In this context, it becomes necessary the proposition of new operational and control strategies for microgrids control, taking into account the presence of distributed generation units based on full-rated converter. This paper proposes an operational and control strategy for the islanded operation of a winddiesel microgrid with high insertion level of wind generation. The microgrid adopted in this study comprises of a wind energy conversion system with synchronous generator based on full rated converter, a diesel generator (DIG) and a dump load. Due to the high insertion level of wind generation, the wind unit operates in Vf mode and the diesel generator operates in PQ mode. The diesel generator and the dump load are used to regulate the DC-link voltage of the wind generation unit. The proposed control allows the islanded operation of the microgrid only with wind generation, wind-only mode (WO), and with wind-diesel generation, wind-diesel mode (WD). For the wind-only mode, with 100% of penetration level of wind generation, it is proposed a DC-link voltage control loop based on the use of a DC dump load. For the winddiesel mode, it is proposed a DC-link voltage control loop added to the diesel generator, which is connected to the AC side of the microgrid, in coordinated action with the dump load. The proposed operational and control strategy does not require the use of batteries and aims to maximize the energy production from wind generation, ensuring the uninterrupted operation of the microgrid. The results have showed that the operational and control strategy allowed the stable operation of the islanded microgrid and that the DC-link voltage control loop added to the diesel generator and the dump load proved to be effective during the typical variations of wind speed and load.
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This study presents a proposal of speed servomechanisms without the use of mechanical sensors (sensorless) using induction motors. A comparison is performed and propose techniques for pet rotor speed, analyzing performance in different conditions of speed and load. For the determination of control technique, initially, is performed an analysis of the technical literature of the main control and speed estimation used, with their characteristics and limitations. The proposed technique for servo sensorless speed induction motor uses indirect field-oriented control (IFOC), composed of four controllers of the proportional-integral type (PI): rotor flux controller, speed controller and current controllers in the direct and quadrature shaft. As the main focus of the work is in the speed control loop was implemented in Matlab the recursive least squares algorithm (RLS) for identification of mechanical parameters, such as moment of inertia and friction coefficient. Thus, the speed of outer loop controller gains can be self adjusted to compensate for any changes in the mechanical parameters. For speed estimation techniques are analyzed: MRAS by rotóricos fluxes MRAS by counter EMF, MRAS by instantaneous reactive power, slip, locked loop phase (PLL) and sliding mode. A proposition of estimation in sliding mode based on speed, which is performed a change in rotor flux observer structure is displayed. To evaluate the techniques are performed theoretical analyzes in Matlab simulation environment and experimental platform in electrical machinery drives. The DSP TMS320F28069 was used for experimental implementation of speed estimation techniques and check the performance of the same in a wide speed range, including load insertion. From this analysis is carried out to implement closed-loop control of sensorless speed IFOC structure. The results demonstrated the real possibility of replacing mechanical sensors for estimation techniques proposed and analyzed. Among these, the estimator based on PLL demonstrated the best performance in various conditions, while the technique based on sliding mode has good capacity estimation in steady state and robustness to parametric variations.
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Positioning and orientation precision of a multirotor aerial robot can be increased by using additional control loops for each of the driving units. As a result, one can eliminate lack of balance between true thrust forces. A control performance comparison of two proposed thrust controllers, namely robust controller designed with coefficient diagram method (CDM) and proportional, integral and derivative (PID) controller tuned with pole-placement law, is presented in the paper. The research has been conducted with respect to model/plant matching uncertainty and with the use of antiwindup compensators for a simple motor-rotor model approximated by first-order inertia plus delay. From the obtained simulation results one concludes that appropriate choice of AWC compensator improves tracking performance and increases robustness against parametric uncertainty.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, 2015.
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Current space exploration has transpired through the use of chemical rockets, and they have served us well, but they have their limitations. Exploration of the outer solar system, Jupiter and beyond will most likely require a new generation of propulsion system. One potential technology class to provide spacecraft propulsion and power systems involve thermonuclear fusion plasma systems. In this class it is well accepted that d-He3 fusion is the most promising of the fuel candidates for spacecraft applications as the 14.7 MeV protons carry up to 80% of the total fusion power while ‘s have energies less than 4 MeV. The other minor fusion products from secondary d-d reactions consisting of 3He, n, p, and 3H also have energies less than 4 MeV. Furthermore there are two main fusion subsets namely, Magnetic Confinement Fusion devices and Inertial Electrostatic Confinement (or IEC) Fusion devices. Magnetic Confinement Fusion devices are characterized by complex geometries and prohibitive structural mass compromising spacecraft use at this stage of exploration. While generating energy from a lightweight and reliable fusion source is important, another critical issue is harnessing this energy into usable power and/or propulsion. IEC fusion is a method of fusion plasma confinement that uses a series of biased electrodes that accelerate a uniform spherical beam of ions into a hollow cathode typically comprised of a gridded structure with high transparency. The inertia of the imploding ion beam compresses the ions at the center of the cathode increasing the density to the point where fusion occurs. Since the velocity distributions of fusion particles in an IEC are essentially isotropic and carry no net momentum, a means of redirecting the velocity of the particles is necessary to efficiently extract energy and provide power or create thrust. There are classes of advanced fuel fusion reactions where direct-energy conversion based on electrostatically-biased collector plates is impossible due to potential limits, material structure limitations, and IEC geometry. Thermal conversion systems are also inefficient for this application. A method of converting the isotropic IEC into a collimated flow of fusion products solves these issues and allows direct energy conversion. An efficient traveling wave direct energy converter has been proposed and studied by Momota , Shu and further studied by evaluated with numerical simulations by Ishikawa and others. One of the conventional methods of collimating charged particles is to surround the particle source with an applied magnetic channel. Charged particles are trapped and move along the lines of flux. By introducing expanding lines of force gradually along the magnetic channel, the velocity component perpendicular to the lines of force is transferred to the parallel one. However, efficient operation of the IEC requires a null magnetic field at the core of the device. In order to achieve this, Momota and Miley have proposed a pair of magnetic coils anti-parallel to the magnetic channel creating a null hexapole magnetic field region necessary for the IEC fusion core. Numerically, collimation of 300 eV electrons without a stabilization coil was demonstrated to approach 95% at a profile corresponding to Vsolenoid = 20.0V, Ifloating = 2.78A, Isolenoid = 4.05A while collimation of electrons with stabilization coil present was demonstrated to reach 69% at a profile corresponding to Vsolenoid = 7.0V, Istab = 1.1A, Ifloating = 1.1A, Isolenoid = 1.45A. Experimentally, collimation of electrons with stabilization coil present was demonstrated experimentally to be 35% at 100 eV and reach a peak of 39.6% at 50eV with a profile corresponding to Vsolenoid = 7.0V, Istab = 1.1A, Ifloating = 1.1A, Isolenoid = 1.45A and collimation of 300 eV electrons without a stabilization coil was demonstrated to approach 49% at a profile corresponding to Vsolenoid = 20.0V, Ifloating = 2.78A, Isolenoid = 4.05A 6.4% of the 300eV electrons’ initial velocity is directed to the collector plates. The remaining electrons are trapped by the collimator’s magnetic field. These particles oscillate around the null field region several hundred times and eventually escape to the collector plates. At a solenoid voltage profile of 7 Volts, 100 eV electrons are collimated with wall and perpendicular component losses of 31%. Increasing the electron energy beyond 100 eV increases the wall losses by 25% at 300 eV. Ultimately it was determined that a field strength deriving from 9.5 MAT/m would be required to collimate 14.7 MeV fusion protons from d-3He fueled IEC fusion core. The concept of the proton collimator has been proven to be effective to transform an isotropic source into a collimated flow of particles ripe for direct energy conversion.
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Cranial cruciate ligament (CCL) deficiency is the leading cause of lameness affecting the stifle joints of large breed dogs, especially Labrador Retrievers. Although CCL disease has been studied extensively, its exact pathogenesis and the primary cause leading to CCL rupture remain controversial. However, weakening secondary to repetitive microtrauma is currently believed to cause the majority of CCL instabilities diagnosed in dogs. Techniques of gait analysis have become the most productive tools to investigate normal and pathological gait in human and veterinary subjects. The inverse dynamics analysis approach models the limb as a series of connected linkages and integrates morphometric data to yield information about the net joint moment, patterns of muscle power and joint reaction forces. The results of these studies have greatly advanced our understanding of the pathogenesis of joint diseases in humans. A muscular imbalance between the hamstring and quadriceps muscles has been suggested as a cause for anterior cruciate ligament rupture in female athletes. Based on these findings, neuromuscular training programs leading to a relative risk reduction of up to 80% has been designed. In spite of the cost and morbidity associated with CCL disease and its management, very few studies have focused on the inverse dynamics gait analysis of this condition in dogs. The general goals of this research were (1) to further define gait mechanism in Labrador Retrievers with and without CCL-deficiency, (2) to identify individual dogs that are susceptible to CCL disease, and (3) to characterize their gait. The mass, location of the center of mass (COM), and mass moment of inertia of hind limb segments were calculated using a noninvasive method based on computerized tomography of normal and CCL-deficient Labrador Retrievers. Regression models were developed to determine predictive equations to estimate body segment parameters on the basis of simple morphometric measurements, providing a basis for nonterminal studies of inverse dynamics of the hind limbs in Labrador Retrievers. Kinematic, ground reaction forces (GRF) and morphometric data were combined in an inverse dynamics approach to compute hock, stifle and hip net moments, powers and joint reaction forces (JRF) while trotting in normal, CCL-deficient or sound contralateral limbs. Reductions in joint moment, power, and loads observed in CCL-deficient limbs were interpreted as modifications adopted to reduce or avoid painful mobilization of the injured stifle joint. Lameness resulting from CCL disease affected predominantly reaction forces during the braking phase and the extension during push-off. Kinetics also identified a greater joint moment and power of the contralateral limbs compared with normal, particularly of the stifle extensor muscles group, which may correlate with the lameness observed, but also with the predisposition of contralateral limbs to CCL deficiency in dogs. For the first time, surface EMG patterns of major hind limb muscles during trotting gait of healthy Labrador Retrievers were characterized and compared with kinetic and kinematic data of the stifle joint. The use of surface EMG highlighted the co-contraction patterns of the muscles around the stifle joint, which were documented during transition periods between flexion and extension of the joint, but also during the flexion observed in the weight bearing phase. Identification of possible differences in EMG activation characteristics between healthy patients and dogs with or predisposed to orthopedic and neurological disease may help understanding the neuromuscular abnormality and gait mechanics of such disorders in the future. Conformation parameters, obtained from femoral and tibial radiographs, hind limb CT images, and dual-energy X-ray absorptiometry, of hind limbs predisposed to CCL deficiency were compared with the conformation parameters from hind limbs at low risk. A combination of tibial plateau angle and femoral anteversion angle measured on radiographs was determined optimal for discriminating predisposed and non-predisposed limbs for CCL disease in Labrador Retrievers using a receiver operating characteristic curve analysis method. In the future, the tibial plateau angle (TPA) and femoral anteversion angle (FAA) may be used to screen dogs suspected of being susceptible to CCL disease. Last, kinematics and kinetics across the hock, stifle and hip joints in Labrador Retrievers presumed to be at low risk based on their radiographic TPA and FAA were compared to gait data from dogs presumed to be predisposed to CCL disease for overground and treadmill trotting gait. For overground trials, extensor moment at the hock and energy generated around the hock and stifle joints were increased in predisposed limbs compared to non predisposed limbs. For treadmill trials, dogs qualified as predisposed to CCL disease held their stifle at a greater degree of flexion, extended their hock less, and generated more energy around the stifle joints while trotting on a treadmill compared with dogs at low risk. This characterization of the gait mechanics of Labrador Retrievers at low risk or predisposed to CCL disease may help developing and monitoring preventive exercise programs to decrease gastrocnemius dominance and strengthened the hamstring muscle group.
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The five short stories in this collection illustrate the insistence of the imagination in a foreign country. The protagonists deal with loss and exile of the human spirit, as well as language. In “View of the Taft Bridge”, a Chinese painter befriends a panda in the National Zoo in America’s capital. In “Early June before the Millennium”, an illicit student and teacher relationship unveils a painful history of the 1989 Tiananmen Square massacre. An adopted teenager finds her life unraveled at the presence of a new tenant who shares her ethnicity in “Girl in the Basement”. And the inertia of a housewife drives her desire to become a house cat, in “Catwoman”, until dream and reality become interchangeable. In “The Way We Mourned”, betrayal and memorial are closely knit in the wake of a close friend’s death. These stories search for connections to bridge “self” and “other”, as well as one’s present with a haunting past.
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Ultimamente muitas investigações têm sido levadas a cabo em diferentes áreas das Ciências Sociais e Humanas, nas quais o fenómeno de inércia, suas causas e resultados têm sido estudados, a saber: na Filosofia (Ética e Praxeologia), na Psicologia ou na Teoria Organizacional. Todavia, parece que a literatura científica das Ciências Sociais, maioritariamente baseada em estudos empíricos, nos quais a inércia é uma das variáveis independentes, carece de reflexão teórica. O problema de inércia organizacional é analisado no presente artigo como um caso específico da inércia do comportamento humano. Este artigo aborda apenas algumas questões relacionadas com a inércia do comportamento humano: o problema da aplicação directa do princípio mecânico para a área psicossocial, algumas concepções deste fenómeno nas Ciências Sociais com especial enfoque na Teoria organizacional, bem como a avaliação deste fenómeno. Por estas razões, o texto concentra- se nos aspectos conceptuais do fenómeno, levantando mais questões do que dando respostas. Tem um carácter introdutório a futuras investigações.