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first_imgGround‐based measurements of stratospheric slant column NO2 amounts made at Halley Bay, Antarctica in 1987 are compared with ozone and temperature profiles from balloon‐borne sondes. Sunrise‐to‐sunset (am/pm) ratios of NO2 have been calculated in autumn and spring by using the sonde data in conjunction with a simple photochemical model for the conversion of NO2 to N2O5. These calculations can be reconciled with the spectrometric measurements of column NO2, provided that the bulk of the NO2 layer is assumed to lie at a height of about 25km. The small amounts of NO2 that are present in the stratospheric column during the first 6 weeks of spring are therefore confined to altitudes above the ozone depletion region. Slow recovery of the NO2 column in spring compared with the rate of its decline in autumn indicates slow photolysis of depleted levels of N2O5 inside the polar vortex.last_img read more


first_imgBipolarity, the presence of a species in the high latitudes separated by a gap in distribution across the tropics, is a well-known pattern of global species distribution. But the question of whether bipolar species have evolved independently at the poles since the establishment of the cold-water provinces 16–8 million years ago, or if genes have been transferred across the tropics since that time, has not been addressed. Here we examine genetic variation in the small subunit ribosomal RNA gene of three bipolar planktonic foraminiferal morphospecies. We identify at least one identical genotype in all three morphospecies in both the Arctic and Antarctic subpolar provinces, indicating that trans-tropical gene flow must have occurred. Our genetic analysis also reveals that foraminiferal morphospecies can consist of a complex of genetic types. Such occurrences of genetically distinct populations within one morphospecies may affect the use of planktonic foraminifers as a palaeoceanographic proxy for climate change and necessitate a reassessment of the species concept for the group.last_img read more


first_imgProcellariiform seabirds (petrels, albatrosses and shearwaters) forage over thousands of square kilometres for patchily distributed prey resources. While these birds are known for their large olfactory bulbs and excellent sense of smell, how they use odour cues to locate prey patches in the vast ocean is not well understood. Here, we investigate species-specific responses to 3-methyl pyrazine in a sub-Antarctic species assemblage near South Georgia Island (54degrees00′ S, 36degrees00′ W). Pyrazines are scented compounds found in macerated Antarctic krill (Euphausia superba), a primary prey item for many seabird species in this region. To examine behavioural attraction to this odour, we presented birds with either scented or ‘unscented’ vegetable oil slicks at sea. As a positive control for our experiments, we also compared birds’ responses to a general olfactory attractant, herring oil. Responses to pyrazine were both highly species specific and consistent with results from earlier studies investigating responses to crude krill extracts. For example, Cape petrels (Daption capense), giant petrels (Macronectes sp.) and white-chinned petrels (Procellaria aequinoctialis) were sighted at least 1.8-4 times as often at pyrazine-scented slicks than at control slicks. Black-browed albatrosses (Diomedea melanophris) were only sighted at pyrazine-scented slicks and never at control slicks. Wilson’s storm-petrels (Oceanites oceanicus), black-bellied storm-petrels(Fregetta tropica), great shearwaters (Puffinus gravis) and prions (Pachyptila sp.) were sighted with equal frequency at control and pyrazine-scented slicks. As expected, responses to herring oil were more common. With the exception of great shearwaters (Puffinus gravis), each of these species was sighted up to five times as often at slicks scented with herring oil compared with control slicks. Together, the results support the hypothesis that Antarctic procellariiforms use species-specific foraging strategies that are inter-dependent and more complex than simply tracking prey by scent.last_img read more


first_imgChanges in penguin abundance and distribution can be used to understand the response of species to climate change and fisheries pressures, and as a gauge of ecosystem health. Traditionally, population estimates have involved direct counts, but remote sensing and digital mapping methodologies can provide us with alternative techniques forassessing the size and distribution of penguin populations.Here, we demonstrate the use of a field-based digital mapping system (DMS), combining a handheld geographicinformation system with integrated geographical positioningsystem as a method for: (a) assessing penguin colony areaand (b) ground-truthing colony area as derived from satellite imagery. Work took place at Signy Island, South Orkneys, where colonies of the three congeneric pygoscelid penguins: Ade´lie Pygoscelis adeliae, chinstrap P. antarctica and Gentoo P. papua were surveyed. Colony areas were derived by mapping colony boundaries using the DMS with visual counts of the number of nesting birds made concurrently. Area was found to be a good predictor for number of nests for all three species of penguin. Using a maximum likelihood multivariate classification of remotely sensed satellite imagery (QuickBird2, 18 January 2010; Digital Globe ID: 01001000B90AD00), we were able to identify penguin colonies from the spectral signature of guano and differentiate between colonies of Ade´lie and chinstrap penguins. The area classified (all species combined) from satellite imagery versus area from DMS data was closely related (R2 = 0.88). Combining these techniques gives a simple and transferrable methodology for examining penguin distribution and abundance at local and regional scales.last_img read more


first_imgPlanococcus kocurii ATCC 43650T is a halotolerant and psychrotolerant bacterium isolated from the skin of a North sea cod. Here, we present the first complete genome and annotation of P. kocurii ATCC 43650T, identifying its potential as a plant growth promoting bacterium and its capability in the biosynthesis of butanol.last_img


first_imgIn order to understand atmospheric methane (CH4) biogeochemistry now and in the future, we must apprehend its natural variability, without anthropogenic influence. Samples of ancient air trapped within ice cores provide the means to do this. Here we analyze the ultrahigh-resolution CH4 record of the West Antarctic Ice Sheet Divide ice core 67.2–9.8 ka and find novel, atmospheric CH4 variability at centennial time scales throughout the record. This signal is characterized by recurrence intervals within a broad 80–500 year range, but we find that age-scale uncertainties complicate the possible isolation of any periodic frequency. Lower signal amplitudes in the Last Glacial relative to the Holocene may be related to incongruent effects of firn-based signal smoothing processes. Within interstadial and stadial periods, the peak-to-peak signal amplitudes vary in proportion to the underlying millennial-scale oscillations in CH4 concentration—the relative amplitude change is constant. We propose that the centennial CH4 signal is related to tropical climate variability that influences predominantly low-latitude wetland CH4 emissionslast_img read more


first_imgWe use data from eight satellites to statistically examine the role of chorus as a potential source of plasmaspheric hiss. We find that the strong equatorial (|λm| < 6o) chorus wave power in the frequency range 50 < f < 200 Hz does not extend to high latitudes in any MLT sector and is unlikely to be the source of the low frequency plasmaspheric hiss in this frequency range. In contrast, strong equatorial chorus wave power in the medium frequency range 200 < f < 2000 Hz is observed to extend to high latitudes and low altitudes in the pre‐noon sector, consistent with ray tracing modelling from a chorus source and supporting the chorus to hiss generation mechanism. At higher frequencies, chorus may contribute to the weak plasmaspheric hiss seen on the dayside in the frequency range 2000 < f < 3000 Hz band, but is not responsible for the weak plasmaspheric hiss on the nightside in the frequency range 3000 < f < 4000 Hz.last_img read more


first_img FacebookTwitterLinkedInEmailPROVO, Utah – Gonzaga rallied late to spoil Blake Inouye’s solid outing and an opportunity for a BYU sweep Saturday in a 4-3 decision at Larry H. Miller Field.“When two good teams play, you win or lose with a play here or there,” BYU head coach Mike Littlewood said. “We saw some good things this week.”The Bulldogs (12-10, 3-3 West Coast Conference) used a single and a Cougar error en route to loading the bases in the eighth with a 1-1 tie. A single, two walks and a hits batsman plated three Zags and BYU (12-10, 2-4 WCC) was unable to come back.Inouye started for the Cougars and allowed just four hits and one earned run in six innings of work.“Blake (Inouye) gave us exactly what we needed,” Littlewood said. “He showed us that he can definitely be a starter for us.”BYU scored first by getting Mitch McIntyre over and in after he reached on an error in the third. Gonzaga squared it up at 1-1 with a pair of hits in the sixth.The Cougars responded to the Bulldogs’ eighth-inning rally by putting up a pair of runs in the bottom half. Jarrett Perns led off the inning with a double and Keaton Kringlen and Brian Hsu singled. However, BYU stranded runners on the corners with a 6-3-6 double play groundout.On Tuesday, the Cougars play at UVU in the second leg of the UCCU Crosstown Clash (BYU won the first game 9-3 in Provo). Then, they play a three-game weekend series at Pepperdine.​ March 24, 2018 /Sports News – Local Three-run eighth dooms Cougars in 4-3 loss to Gonzaga Written by Tags: Baseball/BYU Cougars/WCC Robert Lovelllast_img read more


first_imgOctober 16, 2018 /Sports News – Local USU Men’s Basketball Picked To Finish 9th in Mountain West Written by FacebookTwitterLinkedInEmailLAS VEGAS-Tuesday, during the Mountain West Conference’s men’s basketball media day, Utah State was picked to finish ninth by media from around the league.The Aggies received 78 overall votes, finishing ahead of Air Force and San Jose State.Burgeoning national power Nevada, who made the Sweet Sixteen in last season’s NCAA Tournament, is the unanimous favorite to win the conference.The Wolf Pack netted 207 votes, including 18 first-place votes. San Diego State is slated to finish second, while the Aztecs received one first-place vote and 188 overall votes.New Mexico was slated to finish third, with Boise State in fourth, Fresno State in fifth, UNLV in sixth, Wyoming in seventh and Colorado State in eighth.The Aggies will be led by returning all-Mountain West guard Sam Merrill who led the Aggies with 16.3 points a game last season. He also made 98 3-point field goals, the second-most in a season in program history.After finishing 17-17 last season and 8-10 in Mountain West play, the Aggies brought in a new coach in Craig Smith.Smith comes from the University of South Dakota, where he led the Coyotes to back-to-back postseasons and the 2016-17 Summit League regular season championship.The All-Mountain West preseason team consists of Nevada senior forward Caleb Martin (who is also the conference preseason player of the year), Nevada senior guard/forward Jordan Caroline, Fresno State senior guard Deshon Taylor, Wyoming senior guard Justin James and Nevada senior forward Cody Martin, who is Caleb’s brother. Tags: Air Force/Boise State/Cody Martin/Colorado State/Craig Smith/Deshon Taylor/Fresno State/Jordan Caroline/Justin James/Mountain West Media Days/NCAA Tournament/Nevada/New Mexico/Sam Merrill/San Diego State/San Jose State/Sweet Sixteen/UNLV/Utah State Men’s Basketball/Wyoming Brad Jameslast_img read more


first_img Tags: Big Ten Conference/Iowa Hawkeyes/John Hartwell/USU Football Brad James FacebookTwitterLinkedInEmail Written by The Aggies are 0 -2 all-time against the Hawkeyes and have made two trips to Iowa City, losing 70-14 in 1957 and 48-7 in 2002. Previously, the Aggies have played once at Michigan State, twice at Wisconsin, once apiece at Illinois and Penn State and eight times at Nebraska.center_img This will be the 14th time in program history that the Aggies have played a present member of The Big Ten Conference. January 11, 2019 /Sports News – Local Utah State Football To Play At Iowa in 2023 IOWA CITY, Iowa-Friday, Utah State University vice president and director of athletics, John Hartwell, confirmed the Aggies’ football squad will play at Iowa September 16, 2023. Game time and broadcast plans will be announced at a later date.last_img read more

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