Background: The role of hip arthroscopic intervention for Femoroacetabular impingement (FAI) is evolving with increasing ability to deal with impingement lesions and repair the chondrolabral tears. Initially, the procedure was thought to be most appropriate for treatment of athletes but the objective benefits in terms of return to sport at the same level were not considered. Moreover, any benefit in terms of overall quality of life, and potential efficacy of arthroscopic treatment in non-athletes has not been clarified. Currently, this procedure is still very new, and most published studies involve retrospective analysis of small numbers of patients and do not give an accurate picture of the frequency and severity of complications, in particular the potential to delay the need the have hip replacement. Aim: The aim of this thesis is to establish the benefit of hip arthroscopic intervention for FAI by answering pertinent questions about the procedure: • Is it effective in terms of improvement in quality of life? • Is it beneficial for non-athletes? • Is it possible for athletes to return to sport at the same level? • What is the short-term complication rate? • Does it defer the need to have hip replacement in the future? Methods: This thesis is based on four original published papers in various peer-reviewed journals that address the above questions. Results: Does hip arthroscopic intervention improve quality of life (QoL) of patients with FAI? This publication reported the largest single-surgeon series, at the time of publication, and was the first to consider QoL outcomes. In a series of 612 patients at a mean follow-up of 3.2 years, we found that the QoL improved significantly after surgical intervention in 77%, remained unchanged in 14% and deteriorated in 9% of patients. The significant predictors of change in QoL were preoperative QoL scores and female gender. Is hip arthroscopic intervention for FAI only for athletes? In this prospective comparative study the trend for improvement in hip scores after surgery was compared between athletes and non-athletes and we found that, while the athletes had a significantly better score at six weeks, there were no significant differences between the two groups after one year. This study was the first prospective comparative study to look at these two groups of patients and demonstrated that arthroscopic surgery may be an appropriate treatment for FAI in both athletes and non-athletes. Does hip arthroscopic intervention for FAI improve the outcome in athletes? In this prospective comparative study we noted that both the training and time in competition improved approximately three-fold after surgery, with a mean time to return to sport at the same level of 5.4 months. Professional athletes (4.2 months) recovered more quickly than recreational athletes (6.8 months). A greater proportion of the professional athletes (88%) returned to their pre-injury level of sport than the recreational athletes (73%). Prior to this study, objective measures of return to sport were lacking, and there had been no prospective comparative studies of recovery time in professional and recreational athletes. What is the short-term complication rate? The national hospital episode statistics data on short-term complications after hip arthroscopy showed that, in 6395 hip arthroscopies performed in England between April 2005 and Jan 2013, the 30-day readmission rate was 0.5%; the 90-day incidence of deep vein thrombosis (DVT) was 0.08% and of pulmonary embolus (PE) 0.08%; and the 90-day mortality rate was 0.02%. Does it defer the need to have hip replacement in the future? In this series of 6395 hip arthroscopies, 680 patients (10.6%) underwent total hip replacement (THR), at a mean of 1.4 years after the index operation. Female patients had a 1.68 times (95% CI, 1.41 to 2.01) higher risk of conversion to THR than male patients, and patients aged 50 years or older had a 4.65 (95% CI, 3.93 to 5.49) times higher risk of requiring hip replacement than patients younger than 50 years. Kaplan-Meier survival analysis revealed an eight-year survival of 82%; while Cox proportional hazard analysis, adjusting for age, gender and Charlson comorbidity score, revealed an eight-year survival of 86%. Conclusion: Arthroscopic surgery for FAI improves QoL, is beneficial for non athletes as well as athletes, enables athletes to return to their professional level of function and may delay the need for total hip replacement. These papers have helped, not only in establishing the outcome of surgery but also in identifying the patients who would benefit from intervention. This information is critical to the clinicians’ understanding of both the success of the intervention and limitations of the technique. Important information has been generated from this work that will be helpful during preoperative counselling, when it is imperative to obtain properly informed consent.

Utah lotus (Lotus utahensis Ottley) is a North American legume related to the Eurasian birdsfoot trefoil (L. corniculatus L.), which is an economically valuable forage legume for pastures. Our objectives were to describe the genetic variation within Utah lotus seed collections by measuring adaptive phenotypic traits at three common garden sites in northern Utah, and to determine the genetic structure of populations and the extent of local adaptation through AFLP (amplified fragment length polymorphisms) analysis. We evaluated 14 Utah lotus seed collections from Nevada and Utah, and five seed collections of scrub lotus (L. wrightii (A. Gray) Greene) from Arizona. Significant variation was observed among collections for all phenotypic traits measured. Spring emergence date, flowering date, survival, dry-matter yield, and canopy width discriminated these two species with 100% accuracy. Population structure estimates from 552 AFLP markers of Utah lotus, scrub lotus, and the birdsfoot trefoil check resulted in five genetically differentiated groups. The three primary groups were the three species; within the Utah lotus collections three sub-groups were identified, which corresponded to geographic locations of the collection sites. Two collections of Utah lotus (LU-5 and LU-20) were among the top-tier collections for important phenotypic traits, including dry-matter yield, pod production, number of stems, canopy height, and survival. No significant Pearson’s correlations or canonical correlations were found among the phenotypic traits and environmental characteristics at the collection sites. Significant correlations were detected between genetic and geographic, and phenotypic and geographic distance matrices (r = 0.888, P = 0.001 and r = 0.235, P = 0.044, respectively). No other significant distance matrix correlations were found. Despite the significant isolation by distance correlation, both the genetic and phenotypic evaluations provide little evidence to support local adaptation. Based on these results, one pooled germplasm source of Utah lotus could be developed for use in rangeland restoration and revegetation of the southern Great Basin. Collections LU-5 and LU-20 would be good candidate collections that would represent minimal risk of maladaptation and out-breeding depression with natural populations.

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Beauveria bassiana isolate 11-98 is entomopathogenic, endophytic in tomato, and has biocontrol activity against Rhizoctonia solani on tomato. The objectives of this study were to determine 1) if B. bassiana is endophytic in cotton, following seed treatment; 2) if B. bassiana can protect cotton against seedling pathogens; 3) if different conidial rates, applied to seed, alter effectiveness of B. bassiana; and 4) mechanisms of biocontrol used by B. bassiana against plant pathogens. Cotton ‘Delta Pine 436’ seed was inoculated with isolate 11-98 conidia, sown in a gnotobiotic system, and then isolated from surfacesterilized seedlings on selective medium. Using scanning electron microscopy, hyphal penetration of epithelial cells was observed. Using ITS primers, polymerase chain reaction (PCR), and electrophoresis of PCR products, 11-98 was detected (single 421-bp band) in a dilution series of fungal and plant DNA, and from cotton seedlings endophytically colonized by 11-98. Biocontrol of B. bassiana against R. solani, Pythium myriotylum, and Thielaviopsis basicola was examined using several seed treatment rates (log 5 to log 11 CFU). Disease was suppressed and plant growth was increased in potting mix with B. bassiana at log 7 and log 9 CFU/seed, and in sandy loam soil at log 7 CFU/seed. With low disease pressure from P. myriotylum, seed treated with 11-98 or BotaniGard isolate GHA increased plant growth. Assays with T. basicola were inconclusive. Beauveria bassiana was evaluated for induced systemic resistance in cotton against Xanthomonas axonopodis pv. malvacearum. Root drench treatments were B. bassiana at log 5, log 7, and log 9 CFU/ml, untreated, 2,6-dichloro-isonicotinic acid (INA), and untreated without Xanthomonas. After 13 days, primary leaves were wounded and challenge-inoculated with Xanthomonas. Treatment with B. bassiana (log 7 CFU/seed) had less disease than untreated controls and was as effective as INA. In antibiosis assays, Beauveria bassiana out-competed T. basicola on cotton agar, however no clear zone of inhibition was observed; B. bassiana was outcompeted by R. solani and P. myriotylum, however it maintained its original colony diameter. Beauveria bassiana hyphae coiled around P. myriotylum hyphae in parasitism assays; no coiling was observed with R. solani; results for T. basicola were inconclusive.

I apply the Cox proportional hazards model with independent competing risks to study the hazard rates of executed, cancelled, and partially executed limit orders submitted for Microsoft to the Island ECN for one day. The instantaneous probability of execution increases with decreases in the buy order price but increases to the sell order price, increases in volume on the sell side of the market and market activity. The probability of cancellation increases with increases in the liquidity demand and market activity for buy orders, volume on the same side of the market and absolute market activity for sell orders. Finally, the partially executed hazard rate for buy orders increases with increases in price, volume on the opposite side of the market, size, and absolute market activity; for sell orders, the hazard rate increases with increases in the volume on the same side of the market, liquidity demanded, and market activity.

Limited research exists concerning flash flooding in the United States. However, flash floods can occur anywhere and cause more fatalities than any other weather related natural disaster. Eastern Kentucky experienced an average of 41 flash floods per year (1993-2002), yet little research exists for this region. Therefore, this paper presents an analysis of the particularly devastating flash flood event of 3-4 August 2001, which resulted in $15 million worth of property damage and two deaths. Previous studies indicate that flash floods typically occur under relatively 'benign' conditions, the most common characteristics being a quasi-stationary system and high atmospheric moisture. The slow moving nature of these systems, coupled with low dewpoint depressions, leads to the overabundance of precipitation that produces flash floods. Unfortunately, this relatively 'benign' nature of weather systems poses a challenge for accurate forecasting of flash flooding. Furthermore, severe weather threats, such as tornadoes, tend to overshadow the threats posed by flash flooding, sometimes interfering with the timely issuance of flash flood warnings. To improve the accuracy of flash flood forecasting, several methods have been developed. For instance, lightning strike density helps forecasters in the West to locate regions more likely to receive the heavy rains necessary for flash flooding. Numerical forecasting models also help forecasters, especially when necessary data does not exist for the forecast area. One such model is the Penn State/ NCAR Mesoscale Model MM5. This model consists of several options allowing for variations in climate and terrain. MM5 was used to simulate the 3-4 August 2001 flash flood event, since upper air data does not exist for Eastern Kentucky. The model used for this paper utilized the Grell parameterization scheme, which provided better results than the other parameterization schemes tested (Kain-Fritsch). The Eastern Kentucky flash flood event, like the majority of other flash flood events throughout the Contiguous United States, did in fact occur under relatively benign conditions. This event occurred as heavy rains fell ahead of a trough axis associated with a slow-moving cold front. As the west-east oriented front moved southward, it stalled along the Appalachians and pivoted, becoming southwest-northeast oriented. High atmospheric moisture existed from the surface through 500-mb ahead of the front. The winds were weak and from a northerly direction, while the stability indices indicated marginal instability throughout the event. About half of the flash floods reported during this event occurred prior to the issuance of a flash flood warning, while no record of a flash flood watch existed for any of the counties prior to flash flooding. Accurate forecasting of flash floods during this relatively benign event was further hindered by the lack of a flash flood climatology for the region.

Thèse de doctorat--Universität Frankfurt, 2004. / Bibliogr. p. 305-358.