Memorial University of Newfoundland

About: Memorial University of Newfoundland is a education organization based out in St. John's, Newfoundland and Labrador, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 13818 authors who have published 27785 publications receiving 743594 citations. The organization is also known as: Memorial University & Memorial University of Newfoundland and Labrador.

Rare Earth Element Behavior in Zircon-Melt Systems

Abstract: Natural zircon crystals incorporate rare earth elements (REE) into their structure at concentrations determined by the pressure, temperature, and composition of their growth environment. In principle, REE concentrations in magmatic zircon crystals can be used to infer their conditions of growth and the composition of the melt from which they grew—provided accurate information is available about the distribution of REE between zircon and melt. Currently available zircon-melt partitioning data show a range in values covering several orders of magnitude for some REE. Further experimental work and studies using carefully selected natural samples are required to fully understand REE incorporation in zircon.

Sun-tracking solar furnaces in high arctic flowers: significance for pollination and insects.

Abstract: Heliotropic flowers (Dryas integrifolia, Papaver radicatum) act, in sunshine, as solar reflectors, their corollas focusing heat on the sporophylls. Considerable intrafloral temperatures are generated. Winds above 3.8 meters per second and cloud abolish the effect. Insects that bask in the flowers also gain heat. The phenomena areimportant in maximizing the small heat budget.

Diving Depths of Four Alcids

Abstract: -Incidental catches of 12,243 Common Murres (Uria aalge), 875 Atlantic Puffins (Fratercula arctica), 36 Black Guillemots (Cepphus grylle), and 9 Razorbills (Alca torda) were recorded off Newfoundland during the summers of 1980-1982 (26,445 net-days of fishing effort). Most catch occurred in stationary gill nets set on the sea floor at depths of up to 180 m and revealed that murres, Razorbills, puffins, and guillemots can dive to depths of at least 180, 120, 60, and 50 m, respectively. Diving ability appeared to be directly correlated with body size. Received 5 March 1984, accepted 2 June 1984. LITTLE is known about the depths to which alcids and other aquatic birds are capable of diving (Kooyman 1975). Using depth recorders, Kooyman (1975) and Kooyman et al. (1982) established that Emperor (Aptenodytes forsteri) and King (A. patagonica) penguins can dive to depths in excess of 240 m. Although penguins are probably the best underwater swimmers among the ten families of diving birds, Kooyman (1975) suggested that "If most other birds can descend and ascend at similar rates (e.g. 2 m/s) then a 180 m 'bounce' dive is probably within the range of most diving birds ." properly adapted for the extreme conditions found at those depths. As Northern Hemisphere ecological counterparts to penguins, alcids are morphologically similar. They exploit similar prey, such as euphausiids, squid, and small schooling fishes (Bedard 1969, Kooyman 1975). All pursue prey underwater using partly folded wings to propel themselves (Bedard 1969), and numerous adaptations for underwater "flight" and feeding have evolved in the Alcidae (Storer 1952, Stettenheim 1959, Bedard 1969, Spring 1971). Studies of diets (Tuck and Squires 1955, Belopol'skii 1957) and a few records of catches in fishing gear (Tuck 1961) imply that alcids sometimes forage near the ocean bottom at considerable depths, but there are no detailed accounts of diving ability or estimates of maximum diving depths. In Newfoundland, thousands of alcids, particularly Common Murres (Uria aalge) and Atlantic Puffins (Fratercula arctica), drown each year in surface-set salmon (Salmo salar) and bottom-set cod (Gadus morhua) gill nets as they forage for capelin (Mallotus villosus) in waters intensively fished by man (Piatt et al. 1984). Net-mortality is acute during the one-month period that capelin form large, dense spawning schools inshore. We have accumulated detailed data on 912 incidents involving 13,163 alcids caught in gill nets. These data suggest that the diving abilities of different alcid species differ markedly and that the maximum diving depths attainable by alcids have been considerably underestimated (e.g. Stettenheim 1959, Pearson 1968, Kooyman 1975). STUDY AREA AND METHODS During the summers of 1980-1982, 39 inshore fishermen from communities adjacent to 7 major seabird colonies in Newfoundland (Wadham, Penguin, Cabot, Funk, and Baccalieu islands, Witless Bay, and Cape St. Mary's) recorded daily seabird catches with details on the depths and locations of net entrapment (Piatt et al. 1984). Cod gill nets were positioned on the sea floor at varying depths up to 180 m. The bulk of inshore fishing effort occurs at depths of less than 60 m, and only 5% of fishing effort observed in our study occurred at greater depths. On about 30 occasions John F. Piatt accompanied fishermen at sea and observed fishing techniques and removal of seabirds caught in nets retrieved from depths of up to 180 m. In addition, several thousand net-drowned alcids brought in to fishing wharves were examined, and over one thousand were autopsied to determine sex, age, and stomach contents.

Fine mapping major histocompatibility complex associations in psoriasis and its clinical subtypes.

Abstract: Psoriasis vulgaris (PsV) risk is strongly associated with variation within the major histocompatibility complex (MHC) region, but its genetic architecture has yet to be fully elucidated. Here, we conducted a large-scale fine-mapping study of PsV risk in the MHC region in 9,247 PsV-affected individuals and 13,589 controls of European descent by imputing class I and II human leukocyte antigen (HLA) genes from SNP genotype data. In addition, we imputed sequence variants for MICA, an MHC HLA-like gene that has been associated with PsV, to evaluate association at that locus as well. We observed that HLA-C∗06:02 demonstrated the lowest p value for overall PsV risk (p = 1.7 × 10−364). Stepwise analysis revealed multiple HLA-C∗06:02-independent risk variants in both class I and class II HLA genes for PsV susceptibility (HLA-C∗12:03, HLA-B amino acid positions 67 and 9, HLA-A amino acid position 95, and HLA-DQα1 amino acid position 53; p