6,134 research outputs found

    Choosing an allograft or autograft in orthopedic surgeries for athletes

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    Athletes and their doctors have the choice of using an allograft or autograft in reconstruction surgeries. The purpose of this study is to see if there is a difference in the healing mechanism and surgical outcome in using an allograft or autograft during orthopedic surgical procedures, as well as to analyze graft rejection and disease transmission through donor tissue. Doctors and athletic trainers were interviewed in order to learn about the healing mechanisms and advantages and disadvantages of allografts and autografts in order to conclude if one was better than the other. College level athletes on different sports teams were given a questionnaire that asked questions on the surgical procedure they got and whether or not the surgeon used an allograft or autograft. Specific questions relating to recovery time, stability, and overall function of the area of surgery were asked in order to analyze the outcome. The subjects were screened by choosing athletes with the same surgical reconstruction except one using an allograft and one using an autograft. The questions relating to the outcome of the surgery were compared in order to see if one produced a better outcome over the other. Athletes were found to have better success with autograft as predicted by doctors

    A rare case of leiomyoma of the bladder

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    Bladder leiomyoma is a benign tumour of the bladder and constitute <0.5% of all bladder tumors. We report a clinical case of a 51‑year‑old female who presented with with symptomatic bladder leiomyoma. An ultrasound examination showed well-defined bladder leiomyoma in the right posterior bladder wall, which was excised through a transurethral resection. The pathologic diagnosis was bladder leiomyoma

    Open and / or laparoscopic surgical treatment of liver hydatic cysts

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    Hydatid disease is a severe parasitic disease with a widely ranging distribution. In the human being the liver is the most frequent organ affected. 1 The treatment should be individualized to the morphology, size, number and location of the cysts, that is why a variety of surgical operations have been advocated from complete resection like total pericystectomy or partial hepatectomy to laparoscopy to a minimally invasive procedures like percutaneous aspiration of cysts to conservative drug therapy. 3-4 This study compares laparoscopic versus open management of the hydatid cyst of liver the surgical approach to liver echinococcosis is still a controversial issue and shows our results of surgical treatment of liver hydatid cysts during a 3-years period

    Stochastic background of gravitational waves "tuned" by f(R)f(R) gravity

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    The cosmological background of gravitational waves can be tuned by Extended Theories of Gravity. In particular, it can be shown that assuming a generic function f(R)f(R) of the Ricci scalar RR gives a parametric approach to control the evolution and the production mechanism of gravitational waves in the early Universe.Comment: 5 pages, to appear in the Proceedings of the 3rd Stueckelberg Workshop, July 2008, Pescara - Ital

    Scattering from Solutions of Star Polymers

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    We calculate the scattering intensity of dilute and semi-dilute solutions of star polymers. The star conformation is described by a model introduced by Daoud and Cotton. In this model, a single star is regarded as a spherical region of a semi-dilute polymer solution with a local, position dependent screening length. For high enough concentrations, the outer sections of the arms overlap and build a semi-dilute solution (a sea of blobs) where the inner parts of the actual stars are embedded. The scattering function is evaluated following a method introduced by Auvray and de Gennes. In the dilute regime there are three regions in the scattering function: the Guinier region (low wave vectors, q R << 1) from where the radius of the star can be extracted; the intermediate region (1 << q R << f^(2/5)) that carries the signature of the form factor of a star with f arms: I(q) ~ q^(-10/3); and a high wavevector zone (q R >> f^(2/5)) where the local swollen structure of the polymers gives rise to the usual q^(-5/3) decay. In the semi-dilute regime the different stars interact strongly, and the scattered intensity acquires two new features: a liquid peak that develops at a reciprocal position corresponding to the star-star distances; and a new large wavevector contribution of the form q^(-5/3) originating from the sea of blobs.Comment: REVTeX, 12 pages, 4 eps figure

    Designing optimal low-thrust gravity-assist trajectories using space-pruning and a multi-objective approach

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    A multi-objective problem is addressed consisting of finding optimal low-thrust gravity-assist trajectories for interplanetary and orbital transfers. For this, recently developed pruning techniques for incremental search space reduction - which will be extended for the current situation - in combination with subdivision techniques for the approximation of the entire solution set, the so-called Pareto set, are used. Subdivision techniques are particularly promising for the numerical treatment of these multi-objective design problems since they are characterized (amongst others) by highly disconnected feasible domains, which can easily be handled by these set oriented methods. The complexity of the novel pruning techniques is analysed, and finally the usefulness of the novel approach is demonstrated by showing some numerical results for two realistic cases

    Neurological modeling of what experts vs. non-experts find interesting

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    The P3 and related ERP's have a long history of use to identify stimulus events in subjects as part of oddball-style experiments. In this work we describe the ongoing development of oddball style experiments which attempt to capture what a subject finds of interest or curious, when presented with a set of visual stimuli i.e. images. This joint work between Dublin City University (DCU) and the European Space Agency's Advanced Concepts Team (ESA ACT) is motivated by the challenges of autonomous space exploration where the time lag for sending data back to earth for analysis and then communicating an action or decision back to the spacecraft means that decision-making is slow. Also, when extraterrestrial sensors capture data, the determination of what data to send back to earth is driven by an expertly devised rule set, that is scientists need to determine apriori what will be of interest. This cannot adapt to novel or unexpected data that a scientist may find curious. Our work is attempting to determine if it is possible to capture what a scientist (subject) finds of interest (curious) in a stream of image data through EEG measurement. One of the our challenges is to determine the difference between an expert and a lay subject response to stimulus. To investigate the theorized difference, we use a set of lifelog images as our dataset. Lifelog images are first person images taken by a small wearable camera which continuously records images whilst it is worn. We have devised two key experiments for use with this data and two classes of subjects. Our subjects are a person who has worn the personal camera, from which our collection of lifelog images is taken and who becomes our expert, and the remaining subjects are people who have no association with the captured images. Our first experiment is a traditional oddball experiment where the oddballs are people having coffee, and can be thought of as a directed information seeking task. The second experiment is to present a stream of lifelog images to the subjects and record which images cause a stimulus response. Once the data from these experiments has been captured our task is to compare the responses between the expert and lay subject groups, to determine if there are any commonalities between these groups or any distinct differences. If the latter outcome is the case the objective is then to investigate methods for capturing properties of images which cause an expert to be interested in a presented image. Further novelty is added to our work by the fact we are using entry-level off-the-shelf EEG devices, consisting of 4 nodes with a sampling rate of 255Hz
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