The life and scientific work of William R. Evitt (1923-2009)

Occasionally (and fortunately), circumstances and timing combine to allow an individual, almost singlehandedly, to generate a paradigm shift in his or her chosen field of inquiry. William R. (‘Bill’) Evitt (1923-2009) was such a person. During his career as a palaeontologist, Bill Evitt made lasting and profound contributions to the study of both dinoflagellates and trilobites. He had a distinguished, long and varied career, researching first trilobites and techniques in palaeontology before moving on to marine palynomorphs. Bill is undoubtedly best known for his work on dinoflagellates, especially their resting cysts. He worked at three major US universities and spent a highly significant period in the oil industry. Bill's early profound interest in the natural sciences was actively encouraged both by his parents and at school. His alma mater was Johns Hopkins University where, commencing in 1940, he studied chemistry and geology as an undergraduate. He quickly developed a strong vocation in the earth sciences, and became fascinated by the fossiliferous Lower Palaeozoic strata of the northwestern United States. Bill commenced a PhD project on silicified Middle Ordovician trilobites from Virginia in 1943. His doctoral research was interrupted by military service during World War II; Bill served as an aerial photograph interpreter in China in 1944 and 1945, and received the Bronze Star for his excellent work. Upon demobilisation from the US Army Air Force, he resumed work on his PhD and was given significant teaching duties at Johns Hopkins, which he thoroughly enjoyed. He accepted his first professional position, as an instructor in sedimentary geology, at the University of Rochester in late 1948. Here Bill supervised his first two graduate students, and shared a great cameraderie with a highly motivated student body which largely comprised World War II veterans. At Rochester, Bill continued his trilobite research, and was the editor of the Journal of Paleontology between 1953 and 1956. Seeking a new challenge, he joined the Carter Oil Company in Tulsa, Oklahoma, during 1956. This brought about an irrevocable realignment of his research interests from trilobites to marine palynology. He undertook basic research on aquatic palynomorphs in a very well-resourced laboratory under the direction of one of his most influential mentors, William S. ‘Bill’ Hoffmeister. Bill Evitt visited the influential European palynologists Georges Deflandre and Alfred Eisenack during late 1959 and, while in Tulsa, first developed several groundbreaking hypotheses. He soon realised that the distinctive morphology of certain fossil dinoflagellates, notably the archaeopyle, meant that they represent the resting cyst stage of the life cycle. The archaeopyle clearly allows the excystment of the cell contents, and comprises one or more plate areas. Bill also concluded that spine-bearing palynomorphs, then called hystrichospheres, could be divided into two groups. The largely Palaeozoic spine-bearing palynomorphs are of uncertain biological affinity, and these were termed acritarchs. Moreover, he determined that unequivocal dinoflagellate cysts are all Mesozoic or younger, and that the fossil record of dinoflagellates is highly selective. Bill was always an academic at heart and he joined Stanford University in 1962, where he remained until retiring in 1988. Bill enjoyed getting back into teaching after his six years in industry. During his 26-year tenure at Stanford, Bill continued to revolutionise our understanding of dinoflagellate cysts. He produced many highly influential papers and two major textbooks. The highlights include defining the acritarchs and comprehensively documenting the archaeopyle, together with highly detailed work on the morphology of Nannoceratopsis and Palaeoperidinium pyrophorum using the scanning electron microscope. Bill supervised 11 graduate students while at Stanford University. He organised the Penrose Conference on Modern and Fossil Dinoflagellates in 1978, which was so successful that similar meetings have been held about every four years since that inaugural symposium. Bill also taught many short courses on dinoflagellate cysts aimed at the professional community. Unlike many eminent geologists, Bill actually retired from actively working in the earth sciences. His full retirement was in 1988; after this he worked on only a small number of dinoflagellate cyst projects, including an extensive paper on the genus Palaeoperidinium

A new alternative for a transjugular intrahepatic portosystemic shunt: EUS-guided creation of an intrahepatic portosystemic shunt (with video)

Background: Transjugular intrahepatic portosystemic shunt (TIPSS) is an effective treatment for portal hypertension and its associated complications. EUS-guided creation of an intrahepatic portosystemic shunt (IPSS) may become a useful alternative to conventional TIPSS. Objective: To assess the feasibility of EUS-guided IPSS creation in a live porcine model. Setting: Acute and survival experiments in 50-kg pigs. Design and interventions: Under linear-array EUS guidance, the hepatic vein (HV) and then the portal vein (PV) were punctured with a 19-gauge FNA needle. A 0.035-inch guidewire was advanced through the needle into the PV lumen. The needle was exchanged over the wire, a metal stent was deployed under EUS and fluoroscopic guidance, and the distal end of the stent was positioned inside the PV and the proximal end within the HV. Eight animals were euthanized after the procedure, and 2 animals were kept alive for 2 weeks. Main outcome measurements: Successful EUS-guided IPSS creation. Results: Portosystemic shunt placement was successful in all animals. Intrahepatic vascular puncture and stent deployment were technically easy. Portosystemic flow through the shunt was documented by portal venogram and EUS Doppler. Necropsy performed after acute and survival experiments revealed no evidence of bleeding or damage to any intraperitoneal organs. There were no complications during the follow-up period in the 2 animals that were kept alive. Limitation: Experiments were performed in healthy animals with normal PV pressure. Conclusion: EUS-guided IPSS creation is technically feasible and may become an alternative to the currently used method of TIPSS placement

Physicians' Preferences for Active-controlled versus Placebo-controlled Trials of New Antihypertensive Drugs

To evaluate physicians' preferences for referring patients to, and using information from, active-controlled trials (ACTs) versus placebo-controlled trials (PCTs) of new antihypertensive drugs. DESIGN AND SETTING Nationwide mailed survey, with telephone contact of nonresponders to assess nonresponse bias. PARTICIPANTS: One thousand two hundred primary care physicians randomly selected from the American Medical Association's Master File. Of 1,154 physicians eligible to respond, 651 (56.4%) returned completed questionnaires. MEASUREMENTS AND MAIN RESULTS: We measured physicians' stated willingness to encourage hypertensive patients to enroll in ACTs and PCTs of new antihypertensive drugs, their views of the relative merits of ACTs versus PCTs, their stated willingness to prescribe new drugs tested in ACTs or PCTs, and their views regarding the overall justifiability of the 2 designs. Physicians were significantly more likely to indicate they would encourage their patients to enroll in ACTs than in PCTs ( P < .0001). Physicians thought ACTs provided more valuable information for their practices, were more likely to lead to a public health benefit, offered enrolled patients greater opportunity for personal benefit, and were less likely to expose enrolled patients to unnecessary risks (all P < .0001). Physicians were more likely to prescribe new drugs that had been compared in ACTs ( P < .0001), and viewed ACTs as a more justifiable method for testing new antihypertensive drugs ( P < .0001). There was no evidence of nonresponse bias for these main results. CONCLUSIONS: Although PCTs remain the standard method for testing new antihypertensive drugs, physicians strongly prefer ACTs. Using ACTs to test new antihypertensive drugs may enhance the efficiency of patient recruitment and more strongly influence physicians' prescribing practices.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73302/1/j.1525-1497.2002.11024.x.pd

Links in the functional diversity between soil microorganisms and plant communities during natural succession in coal mine spoil heaps

The successful establishment of vegetation, soil development and biogeochemical cycling during the restoration process of mine tailings requires a diverse and metabolically active microbial communities. The objective of this study was to test whether there is any link between the functional groups of both the dominant plant species and soil microbial communities on unreclaimed coal mine spoil heaps of different age located in the Silesian Upland (Poland). At each sampling site the dominant plant species were recorded and characterised based on their Raunkiaer’s life form, socio-ecological group and their potential to form mycorrhiza. The functional diversity of the plantassociated microbial communities was assessed using the microbial carbon-utilisation guilds generated using the Biolog method. We observed no differences in the microbial functional diversity, but a gradual increase in the plant functional diversity with the age of the heap. Our results indicate that trees, plants with the potential to form ectomycorrhiza, and deciduous plants strongly affected the carbon-utilisation profiles. The mean proportion of microbe guilds in dominant plant patches accounts for 60 % of the variance while the soil physicochemical parameters explained only 30 % of the variance. This suggest that in post-industrial habitats the biotic features of the soil substratum are more important for the vegetation development than the abiotic parameters