189 research outputs found
Determining the need for an expanded fitness component in the Fire Science Program at Milwaukee Area Technical College
No full textIncludes bibliographical references
MR Auswertung der perikardialen und retrosternalen Adhäsionen vor und nach Membraneinpflanzung in der reoperativen Herzchirurgie
No full textEin Ziel dieser prospektiven, randomisierten Arbeit war es, das etablierte Verfahren der Kernspintomographie hinsichtlich ihrer Möglichkeiten in der Diagnostik von möglichen retrosternalen und perikardialen Adhäsionen nach medialen Sternotomien und Re-Operationen zu vergleichen. Bei 10 Patienten benutzten wir eine bioresorbierbare mit Sodium - hyaluronat modifizierte, Carboxymethylcellulose und nicht mondifizierte USP glycerol – Membran (CV seprafilm ®) von Genzyme, Cambridge, MA, USA als perikardialen Ersatz. Die anderen 10 Patienten erhielten eine nichtresorbierbare Polytetrafluoroäthylen (PTFE) - Membran (Preclude ®) der Firma Gore, Flagstaff, AZ, USA. In der Kontrollgruppe waren weitere 10 Patienten, die keine Membranen erhielten. Im Rahmen der vorliegenden Arbeit wurden 34 Patienten zwischen Januar 2000 und Oktober 2002 nach dem Zufall für das MRI postoperativ innerhalb eines Jahres zugewiesen, um mögliche retrosternale und perikardiale Adhäsionen postoperativ zu beurteilen. Weiterhin sah das Protokoll vor, dass bei 20 Patienten vor dem operativen Eingriff ein MRT durchgeführt wurde, während alle Patienten ein Jahr postoperativ eine MR – Untersuchung bekommen sollten. Da vier Patientenn verstorben waren wurde die MR Untersuchung bei 30 Patienten. Durchgeführt. Die prä- und postoperative MR- Auswertung wurde ohne das Wissen von intraoperativen Resultaten durchgeführt. Die präoperative MR- Auswertung wurde mit dem intraoperativen Befund sowie postoperativ im MRT verglichen. Die Untersuchung wurde mit einem Siemens Magnetom Symphony mit einer Feldstärke von 1,5 Tesla durchgeführt. Das Protokoll sah vor, dass transversale- und sagittale T1- gewichtete und EKG- getriggerte Spin- Echo- Sequenzen, sowie transversale- und sagittale retrospektive Gradienten- Echo- Sequenzen durchgeführt wurden. Wir klassifizierten den Grad der perikardialen Adhäsionen in 5 Gruppen: nicht vorhanden (0), minimale (1), mäßig (2), schwere (3), extrem schwer (4). Die perikardialen Adhäsionen wurden an fünf Positionen gemessen und ausgewertet: entlang der großen Gefäße (Aorta ascendens und A. pulmonalis), am rechten Atrium, an ventralen Wand des rechten Ventrikels, an der Herzspitze und an der diaphragmalen Oberfläche (posterolateral). Zum Zeitpunkt vor der Re- Operation war keiner der 30 Patienten frei von retrosternalen und intrapericardialen Adhäsionen. Die präoperative MR- Auswertung der retrosternalen Adhäsionen korrelierte mit dem intraoperativen Befund, während die prognostizierte Dichte der Adhäsionen ebenfalls visuell gemessen und im MRT bewertet weniger zuverlässig im Vergleich zu den intraoperativen Befunden war. Die post-operativen MR- Ergebnisse der Patienten mit der biologisch resorbierbaren Membran (Seprafilm ®) und der nichtresorbierbaren (Preclude ®) Membran zeigte keinen signifikanten Unterschied zur Kontrollgruppe. Aufgrund der Ergebnisse der prä- und postoperativen MR- Bildgebung sowie der intraoperativen Befunde gehen wir davon aus, dass die Kernspintomographie eine angemessene diagnostische Methode zur Erkennung und zur Lokalisation von retrosternalen perikardialen Adhäsionen darstellt. Basierend auf unseren Ergebnissen kommen wir jedoch zu dem Schluss, dass perikardiale Ersatzstoffe wie biologisch resorbierbare oder nichtresorbierbare Membranen nicht in der Lage sind, Adhäsionsformationen für einen Zeitraum von über einem Jahr zu verringern oder zu vermeiden. Unser Studienergebnis erlaubt es nicht ein abschließendes Urteil über die Effizienz der Membranen zu geben, da wir der Auffassung sind, dass die Adhäsionsformationen möglicherweise nach dem Beobachtungszeitraum von einem Jahr nicht vollständig entwickelt sind. Die sehr viel versprechenden Ergebnisse bei der Verhütung von Adhäsionen mit biologisch resorbierbaren oder nichtresorbierbaren Membranen (PTFE) wurden alle nach einem Beobachtungszeitraum von wenigen Wochen bis zu einem Monat erbracht. Innerhalb dieser kurzen Zeit eignet sich der Stellvertreter vor allem der biologisch resorbierbaren Membran mit Natriumhyaluronat und Carboxymethylcellulose zur Verhinderung von Adhäsionen. Diese Tatsache ist von Vorteil für Operationen mit der Notwendigkeit des kurzfristigen reoperativen Eingriffes z.B. im Bauch- oder sogar Perikardraum, die jedoch innerhalb einer berechenbaren gewissen Zeit entfernt werden können. Die PTFE Membranen zeigt jedoch einen festen Aufbau einer Schicht zwischen dem Brustbein und dem Herz. Auf diese Weise bildet sie eine Art Schutzschild auf der Oberfläche des Myokards. Im Bezug auf unsere Erfahrung stellt dies einen deutlichen Vorteil im Falle von Resternotomie dar. Andererseits zeigen die nichtresorbierbaren Membranen wie als auch die biologisch resorbierbaren Membranen keine Verringerung und Vermeidung von Adhäsionen für einen längeren Zeitraum. Deshalb sehen wir eine klare Notwendigkeit von Langzeitstudien mit größeren Studienkollektiven, um die bisher angenommenen Vorteile dieser Art von Membranen im Hinblick auf ihre Fähigkeit zur langfristigen Adhäsionsprophylaxe zu untersuchen. Dies gilt besonders in der Herzchirurgie, wo retrosternale und perikardiale Adhäsionen für ein hohes Risiko für Re-Operationen maßgeblich sind. Weiterhin erwiesen sich die MRT – Untersuchungen in unserer Studie als klinisch gut einsetzbares Verfahren zur Beurteilung von Adhäsionen, des Retrosternalraums und der Morphologie des Herzen, während sich als Nachteil der deutlich höhere Kostenfaktor im Vergleich zur konventionellen Röntgenuntersuchung anführen lässt.In this prospective, randomized study we tried to find out whether two different pericardial membranes, a bioresorbable membrane of carboxymethylcellulose or a nonresorbable membrane of polytetrafluoroethylene (PTFE), which we inserted patients that were admitted for cardiac reoperation, could reduce postoperative pericardial, retrosternal adhesions in comparison to a control group without an implanted membrane. The bioresorbable membrane was placed between the sternum and the anterior wall of the right ventricle, ascending aorta and the apex. The PTFE membrane, which was additionally fixed to the pericardium by four polypropylene sutures, was placed as well. After that the anterior mediastinum was covered with remaining mediastinal tissue as good as possible before, the sternum was closed with seven wires. We used MR imaging to evaluate adhesion formations preoperatively and postoperatively after a year in order to validate the ability to detect adhesions by magnet resonance tomography. Additionally the findings were correlated with the intraoperative evaluated adhesion score. Between January 2000 and October 2002 thirtyfour patients who were admitted for cardiac reoperation were randomly assigned for MR imaging of the chest one year postoperatively to assess possible retrosternal, pericardial adhesions. Twenty of them underwent MR imaging preoperatively as well. Only patients with previous median sternotomy and a first operation, dated at least one year before reoperation, were included in this study. The examinations consisted of transverse and sagittal T1-weighted prospective ECG gated spin-echo (SE) sequences and transverse and sagittal retrospective gated gradient-echo (GE) sequences, performed on a Siemens Magnetom Symphony with a field-strength of 1.5 Tesla. At the time of reoperation we classified the degree of pericardial adhesions into 5 groups: absent (0), minimal (1), moderate (2), severe (3), extreme severe (4). Pericardial adhesions were evaluated at five locations: along the great vessels (ascending aorta and pulmonary artery), at the right atrium, at the anterior wall of the right ventricle, around the apex and down the diaphragmal (posterolateral) surface. At the time of reoperation none of the 30 patients were free of retrosternal, intrapericardial adhesions. Preoperative MR evaluation of adhesions (visually analyzed by interpreting different colour shades and diastolic/systolic measurements) correlated well with intraoperative findings concerning the location of adhesion formations, whereas the predicted density of adhesions 84 also measured and visually evaluated by MR was less reliable compared to the intraoperative adhesion score. Concerning the density of adhesions analyzed in the movie gradient-echo sequences in pre- and one year postoperative MR imaging, there was minimal less density in patients with the bioresorbable membrane at the level of the ascending aorta and pulmonary artery postoperatively but without statistical significance. At the level of the right ventricle patients with bioresorbable membrane showed one year postoperatively even more density than patients with nonresorbable membrane and patients in the control group. At other defined levels postoperatively less density was seen in all three different groups including the control group where no membrane was inserted also without statistical significance. The postoperative MR findings of the patients with bioresorbable membranes (Seprafilm®) and nonresorbable (Preclude®) membranes showed no significant difference to the control group. Due to the results of preoperative and postoperative MR imaging and our intraoperative findings, we assume that magnetic resonance tomography is an appropiate diagnostical method to detect and locate retrosternal and pericardial adhesions one year after cardiac surgery. Based on our results, we conclude that pericardial substitutes like bioresorbable or nonresorbable membranes do not seem to have the ability to prevent adhesion formations for a period of a year. From our point of view, we are not able to make a final statement on the efficiency of membranes since we have to consider that adhesion formations may not have been entirely developed after such a short period of time. The very promising findings in preventing adhesions with bioresorbable or non resorbable PTFE membranes described in animal models result from the fact that all data was evaluated in a rather short period of time, some weeks to one month. Within this period of time the substitutes and especially the bioresorbable membranes of sodium hyaluronate and carboxymethylcellulose seem to be save and are appropiate to prevent adhesion formations effectively. This fact is of advantage for operations with the necessity of short-term reoperation like abdominal stomata or even cardiac assist devices that can be removed within a predictable certain amount of time. Since PTFE membranes build up a solid layer between the sternum and the heart and in this way form some kind of protection shield on the surface of the heart, there will be regarding to our experience an evident benefit in case it comes to resternotomy. But on the other hand these nonresorbable membranes are like bioresorbable membranes not qualified when it comes to reducing and preventing adhesions for a long time. Therefore we see a definite need for long-term studies in order to verify the presumed benefits of these kinds of membranes in terms of their ability to prevent adhesions over years. Especially requirement is in cardiac surgery where retrosternal and pericardial adhesions are responsible for the high risk of cardiac reoperations
Extremální kombinatorika matic, posloupností a množin permutací
No full textTitle: Extremal combinatorics of matrices, sequences and sets of permutations Author: Josef Cibulka Department: Department of Applied Mathematics Supervisor: Doc. RNDr. Pavel Valtr, Dr., Department of Applied Mathematics Abstract: This thesis studies questions from the areas of the extremal theory of {0, 1}-matrices, sequences and sets of permutations, which found many ap- plications in combinatorial and computational geometry. The VC-dimension of a set P of n-element permutations is the largest integer k such that the set of restrictions of the permutations in P on some k-tuple of positions is the set of all k! permutation patterns. We show lower and upper bounds quasiexponential in n on the maximum size of a set of n-element permutations with VC-dimension bounded by a constant. This is used in a paper of Jan Kynčl to considerably improve the upper bound on the number of weak isomorphism classes of com- plete topological graphs on n vertices. For some, mostly permutation, matrices M, we give new bounds on the number of 1-entries an n × n M-avoiding matrix can have. For example, for every even k, we give a construction of a matrix with k2 n/2 1-entries that avoids one specific k-permutation matrix. We also give almost tight bounds on the maximum number of 1-entries in matrices avoiding a fixed layered...Název práce: Extremální kombinatorika matic, posloupností a množin permutací Autor: Josef Cibulka Katedra: Katedra aplikované matematiky Vedoucí disertační práce: Doc. RNDr. Pavel Valtr, Dr., Katedra aplikované ma- tematiky Abstrakt: V této práci se zabýváme oblastmi extremální teorie {0, 1}-matic, posloupností a množin permutací, které mají četná využití v oblasti kombina- torické a výpočetní geometrie. VC-dimenze množiny n-prvkových permutací P je největší celé číslo k takové, že množina zúžení permutací z P na některou k-tici pozic je množina všech k-prvkových permutací. Projdeme všemi třemi zmíněnými oblastmi extremální kombinatoriky, abychom dokázali horní a dolní meze, rostoucí kvaziexponenciálně v n, na maximální možnou velikost množiny n- permutací s VC-dimenzí shora omezenou konstantou. Tento výsledek využívá ve svém článku Jan Kynčl k výraznému snížení horního odhadu na počet tříd slabého izomorfismu úplného topologického grafu na n vrcholech. Dále pro některé, ze- jména permutační, matice M dokážeme nové meze na počet jedniček v M-prosté {0, 1}-matici velikosti n × n. Například pro každé k zkonstruujeme matici s k2 n/2 jedničkami prostou jedné konkrétní permutační matice velikosti k ×...Katedra aplikované matematikyDepartment of Applied MathematicsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult
Improving wellbeing in universities: a transdisciplinary systems change approach
No full textIn order for universities to flourish, we need to ensure that their staff and students are well mentally, physically and socially. Improving wellbeing is an open, systemic and complex challenge, because it contains many interrelated and dynamic problems and concerns. Such challenges cannot be ‘solved’ by using traditional and reductionist problem-solving strategies. In this paper we demonstrate how we worked towards an integrated systemic design and transdisciplinary innovation approach to improve the wellbeing of staff and students at the University of Technology Sydney. We developed a systemic vision of university wellbeing which considers wellbeing a characteristic of the community as a whole, and an integral part of education and research, rather than an issue that needs to be addressed by a separate ‘service’. The transdisciplinary and systemic design approach is further characterised by an ongoing evolutionary action-approach; an integration of diverse ways of knowing including various academic disciplines, Indigenous ways of knowing and community knowledge; and a structured learning strategy to support system change based on mutual learning and reflexivity. We discuss how this case illustrates how transdisciplinary learning approaches can strengthen systemic design practicesMethodologie en Organisatie van Desig
Wideband channel measurements at 60 GHz in different environments
No full textFor future mobile multimedia communication, a Mobile Broadband System is in development, which operates at a frequency of 60 GHz. In order to get a better understanding of 60 GHz propagation effects in different environments with different conditions, several measurements were performed, using a spectrum analyzer and synthesized signal generator for the frequency-domain characterization of the radio channel. In the experiments, a carrier wave (CW) was swept with constant amplitude across the 100 MHz band, centered on 59.9 GHz. The channel frequency response was measured at the receiver side. The results can be used for the design of an OFDM (Orthogonal Frequency Division Multiplex) system. The measurement environments were a corridor and a big college room in a high-rise office building (indoor) and a parking and a grassfield at the side of that building (outdoor). The spectrum samples were taken in each of the environments. From such samples, parameters that describe the wireless channel can be calculated like the Rice parameter k, the path loss coefficients, coherence bandwidth and the delay spread. It was necessary to develop an appropriate measurement analysis, stemming from the fact that the spectrum analyzer gives no information on the phase, only amplitude. Measurement analysis method and results are explained. When more and more dense measurements are performed a more detailed and accurate description of the wireless channel for the different environments is possible.Electrical Engineering, Mathematics and Computer ScienceTelecommunicatie- en Verkeersbegeleidingssysteme
A deterministic Indoor Propagation Prediction Technique using Ray tracing and Field Measurements at 60 GHz
No full textIn this thesis we present a ray tracing (deterministic) method for predicting the received power and the delay spread for indoor scenarios. This method is then applied to a specific environment, where frequency domain measurements have already been conducted. Results for both measured and predicted data are presented in parallel and compared. Additionally, with ray tracing we calculate some parameters that was not possible to measure. The way that several factors (material characteristics, antenna patterns, etc) affect the propagation has also been examined by changing the initial values of the problem.Electrical Engineering, Mathematics and Computer Scienc
Perception of pain, social and functional discomfort during orthodontic treatment
No full textIntroduction/Objective. Pain and social discomfort are common experiences after the insertion of a fixed orthodontic appliance. The aim of the study was to determine the intensity of pain during the first seven days after the placement of a fixed orthodontic appliance, the impact of orthodontic treatment on psychosocial component of the patient and daily life activities in the first month of therapy. Methods. The study included 60 randomly selected patients from the Department of Orthodontics, Faculty of Dental Medicine, Belgrade, Serbia, aged 15 to 20 years. After the insertion of a fixed orthodontic appliance, the patients were given a questionnaire form comprising questions related to the intensity of pain in the first seven days, function of speech and chewing, oral hygiene, injury of the oral mucosa, and social contacts. For the processing of results obtained from the questionnaire ?2 test was used. Results. The largest percentage of respondents (21.7%) rated pain with grade 1, while less than 10% of respondents gave grades 4, 6, 7, 9, and 10. Most of the participants (95%) answered that they had no difficulties with daily life activities caused by the fixed orthodontic appliance. Most respondents (91.7%) did not have any social discomfort, while a small percentage (8.3%) said they had these problems. Conclusion. General intensity of pain that respondents felt during the first seven days after the placement of a fixed orthodontic appliance was low to moderate. For most of the respondents there was no change in social behavior related to the psychosocial component. Except for changes in dietary habits and sores on the oral mucosa of the cheek in the first month of therapy, examines had no major problems with daily life activities.</jats:p
Management in the Function of Enlargement of the Issuing Profit
No full textThe author starts from the thesis that it is especially necessary to manage the production of cash money, taking into consideration and applying the conceptions of modern management. Cash money (metallic and paper) is a specific “product” that is produced according to the needs of monetary traffic, as well as meeting the standards related to modern notaphily, i.e. numismatics. For several reasons, the author elaborates his thesis on the example of the issuing of Croatian contemporary metallic money. The most important of these reasons are that Croatia has its own mint, that issuing metallic money makes it possible to attain significant non-fiscal effects through its management, and that the issuing of national money has wider cultural, social, legal and other dimensions. In the elaboration of his thesis, the author takes into account the influence of the globalization and integration processes in which Croatia is a participant.management, innovation, issuing profit, money, exchange rate, Euroland
Polyporales - försök till en ny klassificering
No full textA new classification of Polyporales. The author gives a brief account of her on-going studies in Polyporales aiming at a new syste- matic classification based of molecular data
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