Aspects of the acid tolerance of algae from the Durham area

Algal samples were collected from a diverse range of aquatic habitats in the Durham area, with pH values ranging from 3.2 - 9.2, and their acid tolerance in culture was investigated. The pH ranges of occurrence of species in the field were tabulated and their ability to survive in culture at pH 3.3 recorded. The results reveal that some species are restricted to low pH environments among the samples taken, whereas other acid tolerant species can also be found at normal or high pH sites. Acid tolerance was found not to be specific to any particular algal division, the only common division not represented among acid tolerant species being the Cyanophyta. This is in agreement with results of investigations in America. Comparison of species found to be acid tolerant from environments other than minewater drainages, with the flora of an acid minewater drainage at Brandon, suggests that pH is probably the major factor determining the flora of the latter, rather than pH-independent factors characteristic of minewater. Evidence was found showing that tolerance of low pH conditions is a characteristic of particular species to a considerable extent, and samples of these species taken from quite alkaline environments were found to survive at low pH in culture. However, there is also some evidence for the occurrence of adaptation within a species and this may be important. No clear patterns emerged from a floral comparison of the Brandon Acid Streams catchment area and the surrounding countryside. Some experiments on transport of algae by air were carried out, but limited data were collected. It appears that the Acid Stream species are not common among the algae in the air a short distance from the Stream

Bidding for Sport Mega-Events

Sport mega-events such as the Olympic Games and FIFA World Cup, or on a smaller scale the Commonwealth Games or regional events, attract competing bids from nations or cities. These bids are mostly made at tax-payers? expense and spending is often large and non-transparent. Our paper addresses the question of why large sums of public money are spent in an attempt to secure uncertain rights to host events which, according to ex post studies, often yield few gains. The paper analyses the economics of the bidding process, emphasising public choice aspects of mega-event bidding to identify the interaction of potential beneficiaries and policymakers' interests. We do not directly enter debates about legacies of hosting mega-events, but ask why public money is spent on a bidding process which is even less likely to realize net social benefits. The empirical part of the paper uses past bids from the state of South Australia, a demonstrated bidder for various sports mega (or not so mega-) events with a mixed record of success, as a case study of the economics of bidding.bidding, sports

The effects of the whole educational experience on graduate employability and further study

A study of recent graduates was conducted in which their present status, campus life experiences, perceptions of their own performances in work or study, and suggestions on improving the curriculum design were explored. Altogether, 315 completed questionnaires were received and the result confirmed that students’ campus involvement positively but weakly correlated with their perceived performances in both working and studying environments after graduation. To enhance students’ involvement in attaining whole educational experience, group-based programmes involving peer activities are suggested

The Art and Science of Immunosuppression: The Fifth Annual American Society of Transplant Surgeon's State-of-the-Art Winter Symposium

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72057/1/j.1600-6143.2005.01187.x.pd

Survival Benefit-Based Deceased-Donor Liver Allocation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74806/1/j.1600-6143.2009.02571.x.pd

Cranial Ontogeny in Stegoceras validum (Dinosauria: Pachycephalosauria): A Quantitative Model of Pachycephalosaur Dome Growth and Variation

Historically, studies of pachycephalosaurs have recognized plesiomorphically flat-headed taxa and apomorphically domed taxa. More recently, it has been suggested that the expression of the frontoparietal dome is ontogenetic and derived from a flat-headed juvenile morphology. However, strong evidence to support this hypothesis has been lacking. Here we test this hypothesis in a large, stratigraphically constrained sample of specimens assigned to Stegoceras validum, the best known pachycephalosaur, using multiple independent lines of evidence including conserved morphology of ornamentation, landmark-based allometric analyses of frontoparietal shape, and cranial bone histology. New specimens show that the diagnostic ornamentation of the parietosquamosal bar is conserved throughout the size range of the sample, which links flat-headed specimens to domed S. validum. High-resolution CT scans of three frontoparietals reveal that vascularity decreases with size and document a pattern that is consistent with previously proposed histological changes during growth. Furthermore, aspects of dome shape and size are strongly correlated and indicative of ontogenetic growth. These results are complementary and strongly support the hypothesis that the sample represents a growth series of a single taxon. Cranial dome growth is positively allometric, proceeds from a flat-headed to a domed state, and confirms the synonymy of Ornatotholus browni as a juvenile Stegoceras. This dataset serves as the first detailed model of growth and variation in a pachycephalosaur. Flat-headed juveniles possess three characters (externally open cranial sutures, tuberculate dorsal surface texture, and open supratemporal fenestrae) that are reduced or eliminated during ontogeny. These characters also occur in putative flat-headed taxa, suggesting that they may also represent juveniles of domed taxa. However, open cranial sutures and supratemporal fenestrae are plesiomorphic within Ornithischia, and thus should be expected in the adult stage of a primitive pachycephalosaur. Additional lines of evidence will be needed to resolve the taxonomic validity of flat-headed pachycephalosaur taxa