Tyrosinase and phenolic pressor amines

Basic to the consideration of the action of tyrosinase on the oxidation of phenolic pressor amines are the observations of Keilin and Mann (16) and of Nelson and his coworkers (17-19) that show that different preparations may vary considerably in their relative actions on monophenols and o-diphenols. Both of these types of activity appear to belong to the same enzyme complex, as they bear a proportionality to the same copper content. However, since the activities vary with the purity and method of purification, each enzyme preparation must be defined in terms of both monophenolase and o-diphenolase activities. This was done in the present studies, and modifications of previously described preparative methods were required to retain a reasonable proportioning of such activities in purified preparations

Dr. Koch: A Cancer Quack?

This paper discusses the life and medical research of Dr. William F. Koch, a physiologist who claimed to have discovered a cure for cancer in the 20th century. Dr. Koch’s early education and research is discussed as background. The paper presents two allegedly successful results of Dr. Koch’s treatment, while also presenting quotes and opinions of skeptics of Dr. Koch’s work. Two FDA trials against Dr. Koch are discussed, as well as a successful FTC trial and appeal. Finally, the paper discusses typical characteristics of a quack, and analyzes Dr. Koch under this rubric. The conclusion of this paper finishes the story of Dr. Koch’s life and highlights some questions remaining understand

Treatment of cholelithiasis and acute cholecystitis : surgical safety in gallstone surgery

INTRODUCTION: Laparoscopic cholecystectomy is one of the most frequently performed surgical procedures worldwide, with nearly 14,000 operations per year in Sweden alone. Recurrent biliary colic or acute cholecystitis are indications for surgery. Despite being a standardized procedure, complications occur in more than 10% of all operations. This thesis includes five research papers, all of which focus on different aspects of surgical safety in gallstone surgery. PAPER 1: The recommended treatment of acute cholecystitis is acute cholecystectomy during the first hospital admission, but the optimal timing is still under discussion. The aim of the first study was to analyse whether the timing of surgery for acute cholecystitis affects complication rates. A registry-based study, based on the Swedish National Registry for Gallstone Surgery and Endoscopic Retrograde Pancreatography (GallRiks) was performed. We included 87,108 patients undergoing cholecystectomy from 2006 to 2014. Of these operations, 15,760 (18.1%) were performed due to acute cholecystitis. We analysed differences in outcomes related to timing of surgery. The results showed that intra-and postoperative complications, bile duct injuries and 30-and 90-day mortality increased with longer delays. The conclusion is that the optimal timing of surgery seems to be within two days of hospital admission. PAPER 2: Increasing hospital and surgeon volumes have been associated with better outcomes for more complicated procedures. However, it is still unknown whether the annual volume of cholecystectomies affects surgical outcomes. The aim of this study was to investigate whether the surgeon’s and hospital’s annual volume of cholecystectomies has an impact on complication rates and operating time. A registry-based study was conducted based on all cholecystectomies registered in GallRiks between 2006 and 2019. A total of 154,934 patients were analysed: 101,221 (65.3%) elective procedures and 53,713 (34.7%) acute procedures. Low volume was defined as <211 operations per hospital per year and <20 operations per surgeon per year. The correlation between annual volumes and different outcomes was calculated. The conclusion is that high volume hospitals and surgeons have more favourable outcomes in both elective and acute cholecystectomy. PAPER 3: Female and male physicians practice medicine differently but it is still unknown whether female and male surgeons produce different outcomes. The aim of this study was to analyse whether female and male surgeons differ in complication rates and operating times in both elective and acute cholecystectomies. A registry-based study was performed based on all cholecystectomies registered in GallRiks between 2006 and 2019. In total, 150,509 patents were included: 97,755 (64.9%) were elective and 52,754 (35.1%) were acute operations. Procedures were performed by 2,553 surgeons: 849 (33.3%) female surgeons and 1,704 (67.7%) male surgeons. Differences in outcomes and operating times were analysed. The results showed that patients operated on by male surgeons had more surgical complications overall (Odds Ratio (OR) 1.29, 95% CI 1.19- 1.40) including more bile duct injures in elective surgery (OR 1.69, 95% CI 1.22-2.34). In addition, female surgeons had longer operating times; converted less frequently to open surgery in the acute setting and their patients had overall shorter hospital stays. The conclusion is that female surgeons have more favourable outcomes but operate more slowly than male surgeons, in elective and acute cholecystectomies. PAPER 4: An alternative to electrocautery dissection is ultrasonic dissection, which has proven favourable in elective cholecystectomies. The aim of this study was to evaluate the learning curve for ultrasonic fundus-first dissection, in elective laparoscopic cholecystectomy. Surgeons with no previous experience of the technique could participate. Patients were recruited between 2017 and 2019. Sixteen residents and specialists, from eight Swedish hospitals, performed 15 operations each and 240 patients were included. The primary endpoint was dissection time with secondary endpoints being complication rate and the surgeon’s self-assessed performance level. In addition, five of the operations were recorded and the videos were graded by two external surgeons. Associations between the procedural number and the different outcomes were analysed. The results showed that dissection time decreased as experience increased (p=0.001). The technique had a complication rate of 5.8%, comparable to the traditional technique. No correlation between the number of performed procedures and the video-assessment score could be demonstrated. The self-assessed performance level was rated lower in more complicated procedures (p=<0.001). The conclusion is that ultrasonic fundus-first dissection is easy to learn and safe during the learning curve, for both residents and specialists. PAPER 5: Ultrasonic dissection seems to be a safe alternative in elective cholecystectomy, but it is still unclear whether the technique is favourable in acute operations. The aim of this study was to compare electrocautery to ultrasonic dissection in patients with acute cholecystitis. A multicentre, randomized, controlled trial was conducted at eight Swedish hospitals. Eligible participants were patients ≥18 years old, with acute cholecystitis with a duration of ≤7 days. Patients were randomly assigned to either traditional electrocautery or ultrasonic dissection, with a 1:1 allocation. Patients, postoperative caregivers, and follow-up personnel were masked to group assignment. The primary endpoint was the total complication rate with analyses according to intention-to-treat. From September 30, 2019, until March 22, 2023, a total of 300 patients was randomized to electrocautery dissection (n=148) or ultrasonic dissection (n=152). No difference in complication rate was seen between the groups (risk difference (RD) 1.6%, 95% CI − 7.2% to 10.4%, p=0.72). Haemostatic agents were used in 40 (27.0%) of patients assigned to electrocautery and 27 (17.8%) of patients assigned to ultrasonic dissection, (RD 10.6%, 95% CI 1.3%-19.8%, p=0.025). In 13 (8.8%) operations in the electrocautery group the surgeon chose to use ultrasonic dissection mostly due to the perceived higher complexity of the operation. The conclusion is that ultrasonic and electrocautery dissection have comparable risks for total complications in patients with acute cholecystitis. Ultrasonic dissection can be used as an alternative to electrocautery dissection, or as a complement in complicated cases

Operations management in the financial services industry in South Africa

Includes bibliographic records.The Southern Life Association Limited, a South African Insurance company, is at the edge of a major transformation. At the beginning of the first research cycle undertaken for this thesis, the company was preparing itself for significant internal changes. At the end of the cycle the company has been sold and is preparing itself to merge with another company to form a Financial Services Industry giant. At both the start and the end of the research, the company had a vision, which was significantly different from its past. Translating this vision into practical actions that drive the company into the future is critical. When significant changes are required, a vital window period exists that allows companies to effectively, efficiently manage and implement change. Should the period, or opportunity, be missed, companies could find themselves lagging behind their competitors, ineffective and having to plough additional resources into ensuring that they catch up. This window period, if effectively managed, can give the company the opportunity to project itself forward and gain a competitive edge. The management at Southern Life had realised the need to change the company. They also knew that the Board of Directors required an improved return on investment. An eighteen-month period was set aside to design and implement the necessary changes. This thesis attempts to look at what management can do to best utilise this window period to the company's best advantage. In order to intervene effectively an Inquiry Framework, or Philosophical Framework of Inquiry as it is referred to, was utilised. This Inquiry Framework is based on the theories and principles of Action and Applied Research, Epistemology, Pragmatism, the Scientific Method and Systems Thinking. When applied rigorously the framework leads one down a path of understanding the situation, raising concerns, developing the hypothesis or question, and providing and evaluating an answer. The research and inquiry process acts like a funnel, allowing the researcher to start broadly and generally and with each cycle, narrowing down to the specific. It aims to facilitate management problem intervention, change and learning in an operational environment. For practical purposes, the thesis focuses on the operational area of the Employee Benefits Division of the company. It reviews the history of the Division in the belief that historical decisions made have led to the current situation. This being a situation of unprofitability, complexity and a multitude of problems

DEFICITS IN FUNCTIONAL MOVEMENT PATTERNS AND RUNNING ECONOMY OF TRAINED ENDURANCE RUNNERS

INTRODUCTION: It has been well established that the mechanics of running gait play a significant role in running economy. Running gait is influenced by many musculoskeletal factors, which can change movement patterns. An individual’s fundamental dynamic movement patterns can be evaluated using the Functional Movement Screen (FMS). Individuals with less movement deficits, specifically asymmetries, may demand less oxygen during activity than individuals with more movement deficits. PURPOSE: This study looked at how deficits in functional movement patterns relate to the running economy of trained endurance runners. Specifically, one aim of this study was to demonstrate that runners who have one or more asymmetries during the FMS demand more oxygen as they run. A second aim was to demonstrate that runners who score 14 or less on the FMS demand more oxygen. A third aim was to demonstrate that runners who score a 2 or less on the Hurdle Step test demand more oxygen than runners who score a 3 on the Hurdle Step FMS test. METHODS: Forty trained endurance runners were tested in the lab on one occasion. Each subject performed all 7 movement tests of the FMS. Next, each subject performed a running economy test consisting of 3 4-minute submaximal trials on the treadmill (women: 10, 12, and 14 km/hr; men: 12, 14, and 16 km/hr). An independent t-test was utilized for each independent variable of interest (asymmetry presence, total FMS score, Hurdle Step score). An alpha of p<0.05 was used to indicate statistical significance. RESULTS: There was a significant difference in running economy between the asymmetrical group (n=21) and the symmetrical group (n=19), only at the speed of 14 km/hour. Contrary to our original hypothesis, the asymmetrical group was more economical than the symmetrical group. Comparing running economy between asymmetrical and symmetrical FMS scorers (men and women together and separately) at all other speeds did not reach statistical significance. There was no difference between running economy of the FMS Hurdle Step test score of 3 group (n=19) and the FMS Hurdle Step test score of 2 or less group (n=21) at any speed. Furthermore, there was no difference between running economy of the FMS Total Score of 14 or less group (n=2) and the FMS Total Score of 15 or more group (n=38) at any speed. CONCLUSION: Trained runners who displayed movement asymmetries as determined by the Functional Movement Screen demonstrated lower oxygen uptakes during submaximal running than runners who were symmetrical on the FMS movements. Although movement asymmetries have been linked to higher injury risk, there may be an advantage of lower metabolic cost during running, which may be due to differences in leg stiffness. Although total FMS score and scores specifically on the hurdle step movement did not influence running economy, the FMS screen remains a staple of pre-participation screening for athletes of all disciplines.Submitted to the faculty of the University Graduate School In partial fulfillment of the requirements for the degree Master of Sciences In the Department of Kinesiology of the School of Public Health Indiana Universit

Large-Scale Pattern-Based Information Extraction from the World Wide Web

Extracting information from text is the task of obtaining structured, machine-processable facts from information that is mentioned in an unstructured manner. It thus allows systems to automatically aggregate information for further analysis, efficient retrieval, automatic validation, or appropriate visualization. This work explores the potential of using textual patterns for Information Extraction from the World Wide Web

Motivations, Classification and Model Trial of Conversational Agents for Insurance Companies

Advances in artificial intelligence have renewed interest in conversational agents. So-called chatbots have reached maturity for industrial applications. German insurance companies are interested in improving their customer service and digitizing their business processes. In this work we investigate the potential use of conversational agents in insurance companies by determining which classes of agents are of interest to insurance companies, finding relevant use cases and requirements, and developing a prototype for an exemplary insurance scenario. Based on this approach, we derive key findings for conversational agent implementation in insurance companies.Comment: 12 pages, 6 figure, accepted for presentation at The International Conference on Agents and Artificial Intelligence 2019 (ICAART 2019