Ziel der Studie war es zu analysieren, inwiefern eine Operation bei Patienten mit einer infektiösen Endokarditis der linksseitigen Nativklappen und keiner weiteren Operationsindikation als einer Vegetationsgröße ≥10mm, das Auftreten von systemischen Embolien, erneuten Endokarditiden und das Langzeitüberleben beeinflussen. Dafür wurden alle Patienten, die zwischen Januar 2000 und Juni 2012 in der Klinik für Kardiologie des Herzzentrums Leipzig mit einer Linksherzendokarditis der Nativklappen und einer Vegetationsgröße ≥10mm behandelt wurden, in ein Register aufgenommen. Alle Patienten mit anderen Operationsindikationen als ihrer Vegetationsgröße wurden ausgeschlossen. Es wurde eine Langzeitkontrolle hinsichtlich definierter klinischer Ereignisse durchgeführt. 71 Patienten wurden in die Studie eingeschlossen. Die mittlere Vegetationsgrößebetrug 17±5mm. 59 Patienten wurden nach einer mittleren Zeit von 5±6 Tagen nach Beginn der Antibiotikatherapie operiert. Die übrigen 12 wurden rein konservativ behandelt. Das mittlere Follow-up erfolgte nach 6,0±2,9 Jahren. Eine chirurgische Behandlungsstrategie war im Vergleich zu rein medikamentöser Therapie mit einer signifikanten Erhöhung der Langzeitmortalität verbunden (p=0,03, Log-rank-Test; unadjustierte Analyse). In einem multivariaten Cox-Regressionsmodell zeigten chirurgische Behandlung, Beteiligung der Mitralklappe, Staphylokokkus aureus-positive Blutkulturen und steigendes Alter einen Trend als unabhängige Beeinflussungsfaktoren der Langzeitmortalität. Ein signifikanter Unterschied zwischen den beiden Gruppen hinsichtlich symptomatischer systemischer Embolien nach Therapiebeginn und Zahl erneuter Endokarditiden bestand nicht. Daher scheint eine operative Behandlung von Patienten mit einer infektiösen Linksherzendokarditis der Nativklappen und großen Vegetationen ohne weitere Operationsindikationen, wie sie aktuell von europäischen und amerikanischen Leitlinien empfohlen wird, möglicherweise mit einer höheren Mortalität verbunden zu sein. Eine kontrollierte randomisierte Studie zur Gegenüberstellung von operativer und konservativer Behandlung dieser Subgruppe von Endokarditispatienten ist deshalb erstrebenswert.

Morley, S. A. (1998). Environmental and parental influences on the size of herring larvae. Ph.D. thesis submitted to the University of Liverpool for the degree of Doctor of Philosophy Investigations were carried out into the effects of mean egg dry weight and incubation temperature on the size of larvae from four N.E. Atlantic herring stocks (Buchan, Manx, Clyde and Celtic Sea). Hatching characterisitics (length, weight and yolk volume) of Buchan, Manx and Clyde herring were investigated. The time of hatching was inversely related to incubation temperature, although there was some variation between experiments in the date of peak hatching. The total length of larvae increased through the hatching period. In all experiments mean egg dry weight per female was strongly related to the average length, weight and yolk volume of larvae at hatching. The same regression model could be applied to all stocks. There were, however, stock-specific responses of hatching characteristics to incubation temperature although a reduction in length at hatching at higher temperatures was the most consistent response. Development at low temperature resulted in a modification of the length-weight relationship; larvae of the same weight were longer at lower temperatures. Both the increase in length of larvae during the hatching period and the variation in the timing of peak hatching have implications for the comparison of larvae hatching at different temperatures. The otoliths of Manx herring larvae [from "large" (> 0.33mg mean dry weight) and "small" «0.2Smg mean dry weight) eggs] were marked with either alizarin complexone or calcein so that larvae from pairs of large and small egg batches could be reared under identical conditions (at both 10 and I3.S0C) and relative growth monitored. Within each rearing tank large eggs generally produced larger larvae at hatch (length and weight) with higher growth rates (both weight and length specific). There were significant differences both between eggs from different females and between rearing tanks that confounded the comparisons between rearing temperatures. Fultons Condition factor is not thought to be a good measure of nutritional condition of herring larvae smaller than ISmm total length but may be used as a relative measure of body reserves (ReF) and give an indication of ability to withstand periods of poor feeding. This is indicated by a period of high mortality of larvae hatched from small eggs at 10°C, which corresponded with the time period when these larvae had the lowest body reserves. Video recording of the foraging behaviour of laboratory reared herring larvae was used to investigate differences between the feeding strategies of groups of larvae of the same size but different ages, i.e. fast and slow growers. Slow growing larvae searched larger areas, thus expending more energy, than fast growing larvae, but there was no difference in food acquisition. The difference in behaviour tended to increase through development A simple energetics calculation suggested that approximately 50% of the difference in growth rate could be explained by the extra swimming costs of slower growing larvae. The size of Celtic Sea and Manx herring eggs were experimentally reduced in order to investigate if the volume of yolk in each egg determines the size of hatching larvae. Length at hatch was determined by the volume of yolk in each egg but body weight was not. The development and chemical composition of embryos and larvae needs to be investigated in a further series of experiments. All results are discussed in terms of the influence of larval size on survival.

Landings are an integral part of New Zealand Harvest operations where extracted trees are processed into logs and loaded out onto trucks. Forest owners need to balance the cost and environmental considerations when designing and constructing landings, with the productivity and safety of the harvesting crew that will use the landing. The objective of this study is to gain a greater understanding of landing size and how they affect forest harvest operations. This study investigates the relationship between landing size and processing delays. A time study was carried out for ten harvest operations predominantly in the lower North Island. The time study recorded all delays on the processing task of measuring and cutting stems into logs. The delays were then categorised so that only processing delays that are influenced by the size of the landing remained. These processing delays were then expressed per m3 and used as the response variable in regression analysis to test their correlation against landing size and a range of other predictor variables. A very strong, linear relationship between processing delays per m3 and actual landing size was found. This indicates that harvest operations on smaller landings exhibited higher delays per m3 than those on larger landings. Loading of the deck was the most significant processing delay; this is a direct result of not having enough room for surge piles as delimbing was not able to be carried out during loader downtime. The significance of the relationships developed in this study can help forest owners realise the implications of building landings that are too small for the intended purpose. Not only will small landings affect productivity, but have the potential to financially affect the forest owner also.

Landings are an integral part of New Zealand Harvest operations where extracted trees are processed into logs and loaded out onto trucks. Forest owners need to balance the cost and environmental considerations when designing and constructing landings, with the productivity and safety of the harvesting crew that will use the landing. The objective of this study is to gain a greater understanding of landing size and how they affect forest harvest operations. This study investigates the relationship between landing size and processing delays. A time study was carried out for ten harvest operations predominantly in the lower North Island. The time study recorded all delays on the processing task of measuring and cutting stems into logs. The delays were then categorised so that only processing delays that are influenced by the size of the landing remained. These processing delays were then expressed per m³ and used as the response variable in regression analysis to test their correlation against landing size and a range of other predictor variables. A very strong, linear relationship between processing delays per m3 and actual landing size was found. This indicates that harvest operations on smaller landings exhibited higher delays per m3 than those on larger landings. Loading of the deck was the most significant processing delay; this is a direct result of not having enough room for surge piles as delimbing was not able to be carried out during loader downtime. The significance of the relationships developed in this study can help forest owners realise the implications of building landings that are too small for the intended purpose. Not only will small landings affect productivity, but have the potential to financially affect the forest owner also.

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This dissertation addresses questions concerning slack's nature and its relationships with the environment and performance. The research investigates which view of slack (the operations or behavioral approach) best predicts performance. It examines the relationship of environment and slack using both interaction and mediation models. The PIMS database was used for 610 assembly manufacturing firms. The results support both the behavioral and the operations perspectives. This combined view suggests that slack capacity is optimized to improve sales while being minimized to improve profits. Excess inventory is minimized to improve sales but optimized to improve average ROS. In all cases, excess cash is minimized. In all equations, the slack variables entered the equations as costs. These results also support the argument that slack interacts with the environment rather than being in a functional relationship with it. Interaction terms of the slack types and the environment were significant in predicting sales. A mediation model was also tested but had a poorer fit with the data. Slack was found to be a multi-dimensional concept. The slack variables did not all intercorrelate positively. The negative relationships suggest that management makes decisions as when to use each slack resource. The slack variables (when lagged) had significant effects on each other, but not on performance. This indicates that the time horizon for slack may be shorter than was investigated in this research. The research demonstrated that slack inventory and non-slack supply buffers were negatively related. The conditions under which the firm trades slack for other buffering mechanisms were not clear. Predicted positive relationships between size and slack were found except that excess capacity and size were negatively related. This suggests that larger firms were holding slack in ways that are more discretionary and less obvious to their control systems. What is not clear from this research are the conditions under which management will choose a specific type of slack. In one case (excess working capital), technology predicts the level of this variable. Additional research is suggested to determine how, when and where these decisions are made.

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No description available.