442 research outputs found

    Embryonic Development in Virtual Reality

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    The overall aim of this thesis is to establish an accurate and reliable description of new in vivo biometric and volumetric measurements in the first trimester of pregnancy using 3D ultrasound datasets, analyzed using an innovative VR system. These new measurements, which make optimal use of all three dimensions, will form a basis for follow-up studies describing the abnormal development of embryonic and early fetal life

    Türkiye’de fizyoloji lisansüstü eğitimine genel bakış

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    A questionnaire was prepared to determine the current situation, characteristics, main problems and solution proposals of post-graduate physiology education in Turkey. The questionnaire was answered by 40% of the physiology departments with post-graduate programs. The results of the questionnaire demonstrate that 31% of master students and 45% of PhD students have academic positions. Most of the post-graduate physiology students are employed in the "academic staff training program" (62% of master and 59% of PhD students). Post-graduate physiology students were mainly composed of biologists (25%) and medical doctors (21%). All or the majority (81%) of postgraduate students have completed their education within the legal periods. We have observed that post-graduate physiology students do not sufficiently benefit from the national and international student exchange programs, scholarships and do not participate in academic activities. Publication rates of the post-graduate thesis in national and international journals are also below the anticipated level. The general problems faced in providing post-graduate physiology education are insufficiency of available academic positions, scholarships, number of academic staff, inadequate financial support in producing qualified research as well as lack of infrastructure. The results of the questionnaire demonstrate that comprehensive studies with broad participation are necessary in order to improve post-graduate education in our country

    Decentralized Robust Control of Robot Manipulators with Harmonic Drive Transmission and Application to Modular and Reconfigurable Serial Arms

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    In this paper, we propose a decentralized robust control algorithm for modular and reconfigurable robots (MRRs) based on Lyapunov’s stability analysis and backstepping techniques. In using decentralized control schemes with robot manipulators, each joint is considered as an independent subsystem, and the dynamical effects from the other links and joints are treated as disturbance. However, there exist many uncertainties due to unmodeled dynamics, varying payloads, harmonic drive (HD) compliance, HD complex gear meshing mechanisms, etc. Also, while the reconfigurability of MRRs is advantageous, modifying the configuration will result in changes to the robot dynamics parameters, thereby making it challenging to tune the control system. All the above mentioned disturbances in addition to reconfigurability present a challenge in controlling MRRs. The proposed controller is well-suited for MRR applications because of its simple structure that does not require the exact knowledge of the dynamic parameters of the configurations. Desired tracking performance can be achieved via tuning a limited set of parameters of the robust controller. If the numbers of degrees of freedom are held constant, these parameters are shown to be relatively independent of the configuration, and can be held constant between changes in configuration. This strategy is novel compared to existing MRR control methods. In order to validate the controller performance, experimental setup and results are also presented

    New Path Equations in Absolute Parallelism Geometry

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    The Bazanski approach, for deriving the geodesic equations in Riemannian geometry, is generalized in the absolute parallelism geometry. As a consequence of this generalization three path equations are obtained. A striking feature in the derived equations is the appearance of a torsion term with a numerical coefficients that jumps by a step of one half from equation to another. This is tempting to speculate that the paths in absolute parallelism geometry might admit a quantum feature.Comment: 4 pages Latex file Journal Reference: Astrophysics and space science 228, 273, (1995

    Smart Power Outlet

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    With an ever-increasing demand on the electrical grid and an increase in electrical consumer goods per household, effective power management and monitoring for home users is a must. The objective of this project is to create a consumer outlet and companion phone application. The power outlet will measure power draw on each socket and report these measurements via an embedded system, wirelessly, to the application. The application will then allow for setting custom power draws at which an individual socket will switch off if exceeded and will display how much a given outlet or individual socket is costing per unit time at current power/electrical rates. The application will also allow for switching on or off any sockets akin to a smart home device and labeling each outlet and socket within the application. The application will enable sending push notifications, if a dangerous or undesirable power draw/current is reached. These features will enable consumers to be more aware of the electricity they are consuming and its associated cost

    Growth, Structure, and Magnetic Properties of Artificially Layered NiMn in Contact to Ferromagnetic Co on Cu3Au(001)

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    Single-crystalline antiferromagnetic artificially layered [Ni/Mn] films of different thicknesses, covered by ferromagnetic Co layers, are deposited on Cu3Au(001).Their structural and magnetic properties are characterized by low-energy electron diffraction (LEED) and magneto-optical Kerr effect, respectively, and compared with disordered NixMn100-x alloy films with the same Ni/Mn ratio and the same film thickness. LEED intensity-versus-energy curves show that the perpendicular inter-atomic lattice distance is decreased in the artificially layered [Ni/Mn] samples incomparison to the disordered NixMn100-x alloy films.At the same time, the artificially layered [Ni/Mn] films exhibit higher coercivity and exchange bias of the adjacent Co layer compared to those of NixMn100-x/Co. This is discussed as a consequence of the different interatomic lattice distance, presumably caused by an ordered buckling in the artificially layered [Ni/Mn] samples, leading to a stronger interlayer exchange coupling

    The correlation between increasing Body Mass Index and the incidence of local recurrence and distant metastasis in breast cancer patients

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    OBJECTIVE: Patients with breast cancer (BC) who are obese or overweight at the time of diagnosis have a low survival rate and a high death rate. We aimed to investigate if having a higher body mass index (BMI) at diagnosis raised the risk of local recurrence (LR) and distant metastasis. PATIENTS AND METHODS: Patients were divided into three categories based on their BMI. The patient's BMI was determined by dividing his weight in kilograms by his height in square meters (kg/m2). The WHO defines normal weight as 18.5 ≤ BMI < 25 kg/m2, overweight as 25 ≤ BMI < 30 kg/m2, and obesity as BMI ≥ 30 kg/m2. RESULTS: The mean BMI was 30.27±6.06 kg/m2. Out of 250 patients, 60 (24.0%), 73 (29.2%) and 117 (46.8%) patients had normal, overweight and obese BMI respectively. No significant difference between BMI and estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2) was found, but there was an association between tumor (T) stage and lymph vascular invasion (LVI) (p<0.05). Obese patients had poorer disease-free survival (DFS) and overall survival (OS) than normal and overweight categories (35.38 ±1.72 vs. 42.38 ± 2.79 and 37.82 ± 2.27 months) (39.65±1.65 vs.45.70 ± 2.53 and 44.31 ± 2.04 months) (p<0.001). LR occurs more prevalent in over-weight and obese patients than normal (p<0.03) but there is no significant difference for distant metastasis. CONCLUSIONS: There is a strong negative association between increased BMI and BC prognosis and patient survival; controlling of this phenomenon may improve the response to treatment and survival, therefore health awareness programs should be implemented

    Accelerated hand bone mineral density loss is associated with progressive joint damage in hands and feet in recent-onset rheumatoid arthritis

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    Introduction: To investigate whether accelerated hand bone mineral density (BMD) loss is associated with progressive joint damage in hands and feet in the first year of rheumatoid arthritis (RA) and whether it is an independent predictor of subsequent progressive total joint damage after 4 years. Methods: In 256 recent-onset RA patients, baseline and 1-year hand BMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry. Joint damage in hands and feet were scored in random order according to the Sharp-van der Heijde method at baseline and yearly up to 4 years. Results: 68% of the patients had accelerated hand BMD loss (>-0.003 g/cm(2)) in the first year of RA. Hand BMD loss was associated with progressive joint damage after 1 year both in hands and feet with odds ratios (OR) (95% confidence intervals [CI]) of 5.3 (1.3-20.9) and 3.1 (1.0-9.7). In univariate analysis, hand BMD loss in the first year was a predictor of subsequent progressive total joint damage after 4 years with an OR (95% CI) of 3.1 (1.3-7.6). Multivariate analysis showed that only progressive joint damage in the first year and anti-citrullinated protein antibody positivity were independent predictors of long-term progressive joint damage. Conclusions: In the first year of RA, accelerated hand BMD loss is associated with progressive joint damage in both hands and feet. Hand BMD loss in the first year of recent-onset RA predicts subsequent progressive total joint damage, however not independent of progressive joint damage in the first year.Pathophysiology and treatment of rheumatic disease
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