Studies of respiratory viruses in personnel at an Antarctic base

first_imgThirteen men wintering on an Antarctic base were isolated from other human contact for 10 months. During this period Coxsackievirus A21 and later influenza A2 virus were administered to some of the men. Serum samples were collected from each of the men at monthly intervals. Coxsackievirus A21 produced symptoms and apparently spread to uninoculated men. It also appears that repeated re-infections occurred and that the virus persisted in this small community for most of the period of isolation. HI antibody responses in the absence of neutralizing antibody responses seem to be transient. The vaccine strain of influenza virus induced antibody responses but did not cause symptoms. There was no evidence of spread to uninoculated men. Antibody titres against influenza C, parainfluenzaviruses 1 and 2 and coronavirus OC43 did not fall significantly during isolation. An outbreak of respiratory illness occurred at the end of isolation and its origin was traced. No causative agent was detected.last_img read more

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British Antarctic Survey, 1974-75

first_imgSeven British Antarctic Survey stations were operational during the year. However, in March 19755 Stonington Island was closed after 21 years of occupation. A number of senior Survey staff visited the bases this season, including Dr R. J. Adie (Deputy Director), Dr C. Swithinbank (Head of Earth Sciences), Mr W. N. Bonner (Head of Life Sciences), Dr J. Dudeney (Leader of the Ionospherics Section), and Mr W. Sloman (Head of Administration).last_img

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Potential interactions between wandering albatrosses and longline fisheries for Patagonian toothfish at South Georgia

first_imgWe examine the extent of overlap between South Georgia wandering albatrosses (Diomedea exulans) and local longline fishing for Patagonian toothfish (Dissostichus eleginoides), using satellite-tracking data and precise haul locations, respectively. We conclude that D. exulans breeding at South Georgia have a relatively low potential risk of interaction with longline fisheries around South Georgia between December and February (incubation period) and between late May and October (main chick-rearing period). However during the chick-brooding period, from March through mid-May, adult birds of both sexes spend most of their time at sea over the South Georgia continental shelf in areas very similar to where the longline fishery operates and are therefore at serious risk from these fisheries at this time. Until fishing methods which do not catch albatrosses are in comprehensive use, we recommend that the South Georgia longline fishery for D. eleginoides should be managed in such a way as to avoid fishing between the end of February and mid-May.last_img read more

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Global-scale tidal structure in the mesosphere and lower thermosphere during the PSMOS campaign of June-August 1999 and comparisons with the global-scale wave model

first_imgObservations of mean winds and semidiurnal and diurnal tides in the mesosphere/lower-thermosphere (MLT) region were made during the 3-month Planetary-Scale Mesopause Observing System Summer 1999 campaign. Data from 22 ground-based radars (and from two other instruments with measurements for the same period but in 1998) allow us to investigate the ability of the GSWM-00 to simulate the solar tides in the mesopause region (90-95 km). Here we have found that the GSWM-00 provides an increasingly reasonable estimate of most of the tidal characteristics in the MLT region. However, the representation of the 24 h tide appears superior to that of the 12 h tide. Some of these discrepancies are studied in detail. In particular, the observations reveal significant 12 h tidal amplitudes at high latitudes in the Northern Hemisphere summer. There is evidence for relation between the longitudinal variability of the mean zonal wind and the tidal characteristics seen from the radar wind measurements in the summer middle latitudes and a quasi-stationary planetary wave with zonal wave number one.last_img read more

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Slow growth of Antarctic bryozoans increases over 20 years and is anomalously high in 2003

first_imgSome organisms are particularly appropriate models for investigation of variability intime and space for given environments. The erect bryozoan Cellarinella nutti, an endemic Antarcticspecies, is one such organism: it is extremely abundant, occurs from the polar front to the Antarcticcontinental edge, and preserves a clear macroscopic environmental record in its skeleton (growthcheck lines). We studied variability in the growth of 93 C. nutti individuals at depths between 247and 414 m, at sites 1, 10, 100 and >1000 km apart in the Weddell Sea, Antarctica. Trawled C. nuttivaried from 5 to 23 yr in age, and nearly half the colonies had grown asexually from fragments. Wemeasured the annual growth increments, which ranged from ~18 zooids (8.6 mg dry mass, 0.8 mgash-free dry mass; Age 1) to ~130 zooids (43 mg dry mass, 2.48 mg ash-free dry mass; Age 20). At 9 yr(the modal age), each C. nutti individual had precipitated >182 mg CaCO3, and by 20 yr nearly580 mg. C. nutti grows slowly compared with other erect bryozoans, even those in the Antarctic. Wefound colony and site to be insignificant factors in its growth, despite the large range of distancesbetween sites, but year was highly significant. We found a non-linear increase in growth spanningthe last 2 decades that has no obvious relation to El Niño Southern Oscillation (ENSO)-associatedenvironmental fluctuations. In particular we found that growth in 2003 was greater than in any otheryear measured by a factor of 2. Given its abundance, longevity, ubiquity in Antarctic waters, insignificantspatial variability in growth, but distinct annual variability, C. nutti may prove to be an importantspecies to investigate whether benthic organisms, as well as krill, salps and fur seals, are beginningto develop major climate-related changes in phenology.last_img read more

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Evolutionary geographic relationships among orthocladine chironomid midges from maritime Antarctic and sub-Antarctic islands

first_imgTwo species of chironomid midges are currently described in the genus Belgica Jacobs, 1900. Belgica antarcticaJacobs, 1900 is endemic to parts of the maritime Antarctic, and Belgica albipes (Séguy, 1965) is endemic to ÎlesCrozet, a sub-Antarctic archipelago in the southern Indian Ocean. The relationships between these species, andtheir closest known relative (Eretmoptera murphyi Schaeffer, 1914, endemic to sub-Antarctic South Georgia), wereexamined by sequencing DNA fragments for domains 1 and 3–5 of 28S ribosomal DNA and the mitochondrial genecytochrome c oxidase 1 (cox1). The resulting molecular relationships between the three species were unclear,although their position within the subfamily Orthocladiinae of the Chironomidae, as generated by classicaltaxonomy, was confirmed. Our data reinforce earlier doubts, based on classical morphological approaches, that thegeneric placement of E. murphyi may be incorrect. Further analyses may indeed confirm that the speciesrepresents a third member of the genus Belgica. Genetic distance analysis, limited to the barcode region of cox1,indicated high differentiation between the two populations of B. albipes sampled (one obtained from the typelocation), suggesting the likely presence of cryptic species within this taxon, and that the taxonomic status of thisspecies should be revised. Analysis of cox1 sequences in B. antarctica highlighted a strong genetic structurebetween populations obtained from 12 locations along the Antarctic Peninsula and the South Shetland Islandsarchipelago, with a number of distinctive mtDNA lineages inhabiting geographically distinct areas. In particular,we found four different haplogroups constituting geographically close but genetically distinct populations, a pattern likely to have been encouraged by the brachyptery of the members of this genus. We suggest that the differentgenetic patterns shown by each haplogroup have probably been determined by historical dispersal and colonizationevents during the Pleistocene, and are consistent with their survival in refuges in situ during successive glacialmaxima over this period.last_img read more

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Love numbers of a generalized Maxwell sphere

first_imgBy elementary methods, we study the Love numbers of a homogeneous, incompressible, self-gravitating sphere characterized by a generalized Maxwell rheology,whose mechanical analogue is represented by a finite or infinite system of classical Maxwell elements disposed in parallel. Analytical, previously unknown forms of thecomplex shear modulus for the generalized Maxwell body are found by algebraic manipulation, and studied in the particular case of systems of springs and dashpots whosestrength follows a power-law distribution. It will be shown that the sphere is asymptotically stable for any choice of the mechanical parameters that define the generalized Maxwell body and analytical forms of the Love numbers are always available for generalized bodies composed by less than five classical Maxwell bodies. For the homogeneous sphere, real Laplace inversion methods based on the Post-Widder formula can be applied without performing a numerical discretization of the n-th derivative, whichcan be computed in a closed-form with the aid of the Faà di Bruno formula.last_img read more

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Too much of a good thing: sea ice extent may have forced emperor penguins into refugia during the last glacial maximum

first_imgThe relationship between population structure and demographic history is critical to understanding microevolution and for predicting the resilience of species to environmental change. Using mitochondrial DNA from extant colonies and radiocarbon-dated subfossils, we present the first microevolutionary analysis of emperor penguins (Aptenodytes forsteri) and show their population trends throughout the last glacial maximum (LGM, 19.5–16 kya) and during the subsequent period of warming and sea ice retreat. We found evidence for three mitochondrial clades within emperor penguins, suggesting that they were isolated within three glacial refugia during the LGM. One of these clades has remained largely isolated within the Ross Sea, while the two other clades have intermixed around the coast of Antarctica from Adélie Land to the Weddell Sea. The differentiation of the Ross Sea population has been preserved despite rapid population growth and opportunities for migration. Low effective population sizes during the LGM, followed by a rapid expansion around the beginning of the Holocene, suggest that an optimum set of sea ice conditions exist for emperor penguins, corresponding to available foraging area.last_img read more

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Rusnak’s late goals help Real Salt Lake beat Dynamo 2-1

first_imgAugust 18, 2018 /Sports News – Local Rusnak’s late goals help Real Salt Lake beat Dynamo 2-1 FacebookTwitterLinkedInEmailHOUSTON (AP) — Albert Rusnak scored two goals in stoppage time to help Real Salt Lake beat the Houston Dynamo 2-1 on Saturday night.Real Salt Lake (11-10-5) won on the road for just the second time this season.Rusnak converted from penalty spot in the 10th minute of injury time to give Real Salt Lake its first lead.Oscar Boniek Garcia gave Houston a 1-0 lead in the 36th minute when he scored his first MLS goal since Aug. 21, 2015. A free kick by the Dynamo bounced high off the wall and Garcia first-timed a volley that deflected off Real Salt Lake’s Nick Besler into the goal.Rusnak faked a shot at the top of the penalty arc, took a couple steps to his left and ripped a left-footer off the far post and into the net to make it 1-1 in the third minute of stoppage time.Joe Willis made saves for the Dynamo to tie his career high.Real Salt Lake’s Andrew Putna had two saves in his first MLS start. The 23-year old signed with the team July 13 and made his first appearance Wednesday night when he replaced injured starter Nick Rimando.The Dynamo (7-11-6) are winless seven games, including five consecutive losses. Written by Tags: MLS/Real Salt Lake/Soccer Associated Presslast_img read more

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BYU Evens Series with LMU

first_img Tags: BYU Cougars Baseball/WCC The Cougars tacked on a seventh run the following inning, again with no hits and thanks to another LMU error. With runners on first and second, the Lion shortstop attempted to complete the double play but the throw went awry, allowing Carson Matthews to continue from third to home. Cluff was intentionally walked and stole second, then Austin Deming walked to load the bases. The Cougars took advantage of another LMU error when the Lion catcher threw a potential pick-off throw over the first baseman, allowing McIntyre and Cluff to score to bring the Cougar margin to 6-3. Player Highlights Danny Gelalich: 2-4, R, RBIJarod Lessar: W (3-1), 2.1 IP, 0 ER, 2 H, 3 KBlake Inouye: S (2), 0.1 IP, 0 ER, 0 H Written by Game Summary FacebookTwitterLinkedInEmailLOS ANGELES – No. 25 BYU baseball evened up the series with LMU, defeating the Lions 8-5 in game two on Friday at Page Stadium. BYU and LMU play the third and final game of the series on Saturday at 1 p.m. PT on TheW.tv, BYU Radio and ESPN 960 AM Different inning, same result for BYU in the eighth when Hill reached on a single, but the throw to first got away from the fielder, allowing Gelalich to score.center_img Six of BYU’s eight runs were unearned due to four LMU errorsFreshman Ryan Sepede hit a single in the ninth for the first hit of his BYU careerWith the win, BYU broke a four-game losing streak to LMU, getting its first victory over the Lions since a 5-4 win in the 2017 WCC Tournament “Our guys fought hard tonight,” BYU head coach Mike Littlewood said. “We kept the pressure on them all night and capitalized on their mistakes.” May 4, 2019 /Sports News – Local BYU Evens Series with LMU Coming into the game ranked 21st in the nation in double plays per game, BYU turned two more on Cluff-to-Deming connections, including an inning-ending play to end a threat in the seventh. Down 3-2 going into the fifth, BYU had a unique inning, scoring four runs on no hits. Noah Hill and Brock Hale reached on a walk and hit by pitch, respectively, before Mitch McIntyre laced a ball between the Lion first baseman’s legs. The ball went all the way to the wall, allowing Hill and Hale to score and McIntyre to reach third on the error. Jarod Lessar came on to earn his third win of the year, pitching 2.1 innings in relief with three strikeouts and no runs. With the tying run at the plate in the bottom of the ninth, Blake Inouye came in to draw out a pop up to end the game and earn his second save. A quick solo home run put LMU on top in the first inning, but the Cougars answered back to take the lead in the top of the second. Jackson Cluff singled and Ryan Sepede walked, then both runners advanced to get in scoring position. Danny Gelalich cashed in one run with a single up the middle and a Carson Matthews groundout scored another to give BYU a 2-1 lead. Robert Lovelllast_img read more

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