Circumpolar response of Southern Ocean eddy activity to a change in the Southern Annular Mode

first_imgAnalysis of satellite altimeter data reveals anomalously high Eddy Kinetic Energy (EKE) in the Antarctic Circumpolar Current (ACC) during the period 2000–2002. Around 2–3 years earlier (1998), the circumpolar eastward wind stress (as quantified by the Southern Annular Mode; SAM) showed a significant positive peak, and we have shown previously that the ACC peaked around 1998 in response. An eddy-resolving ocean model is used to investigate the delay between wind forcing and the eddy response, and demonstrates that the lag is due to the time taken to influence the deep circulation of the ACC. Winds over the Southern Ocean have shown a strong climatic increase over the past few decades. If this increase in winds is also reflected as an increase in eddy activity (as our analysis suggests it might), then the increased poleward heat flux may have played a significant role in the observed warming of the Southern Ocean.last_img read more

Nematode diversity and distribution in the southern maritime Antarctic – clues to history?

first_imgNematode worms are one of the most important soil faunal groups in Antarctica. However, relatively little is known about their widerdistribution, biogeography and history in the region, and taxonomic information remains confused or incomplete. Here, we hypothesisethat the Alexander Island (southern maritime Antarctic) fauna includes elements that have survived (at least) the period of Pleistoceneglaciation in situ, forming a regional centre of endemism and biodiversity hotspot. We describe nematological surveys carried out acrossa latitudinal gradient between 68 and 771S along the southern Antarctic Peninsula, comparing the data obtained with the maritimeAntarctic fauna described in the few previous studies between northern Marguerite Bay and the South Orkney Islands (60–681S). Ingeneral, our survey supports previous findings of a lack of overlap at species level between the maritime and continental Antarcticbiogeographical zones, with the large majority of specimens obtained from all survey sites being attributable to known maritime or newand currently endemic taxa. However, collections from Alexander Island, Alamode Island and the most westerly site sampled, CharcotIsland, include specimens morphologically very close to two known continental Antarctic species, which may indicate a link between thetwo regions. The fauna obtained at the northern study sites (ca. 681S, Adelaide Island, Marguerite Bay) closely matches that describedpreviously. However, in contrast with widely described patterns of decreasing diversity in other Antarctic biota, species richnessincreased markedly at locations on Alexander Island (ca. 721S), including a substantial element of undescribed species (50% of taxaacross all locations, 40% of taxa found on Alexander Island). Finally, the most southerly samples obtained, from inland nunataks inEllsworth Land (75–771S), indicate a fauna that does not include nematodes, which is exceptional not only in an Antarctic context butalso for soils worldwide.last_img read more

Cyanobacteria from benthic mats of Antarctic lakes as a source of new bioactivities

first_imgAims: To exploit the cyanobacterial diversity of microbial mats growing in the benthic environment of Antarctic lakes for the discovery of novel antibiotic and antitumour activities. Methods and results: In all, 51 Antarctic cyanobacteria isolated from benthic mats were cultivated in the laboratory by optimizing temperature, irradiance and mixing. Productivity was generally very low (<= 60 mg l(-1) d(-1)) with growth rates (mu) in the range of 0.02-0.44 d(-1). Growth rates were limited by photosensitivity, sensitivity to air bubbling, polysaccharide production or cell aggregation. Despite this, 126 extracts were prepared from 48 strains and screened for antimicrobial and cytotoxic activities. Seventeen cyanobacteria showed antimicrobial activity (against the Gram-positive Staphylococcus aureus, the filamentous fungus Aspergillus fumigatus or the yeast Cryptococcus neoformans), and 25 were cytotoxic. The bioactivities were not in accordance with the phylogenetic grouping, but rather strain-specific. One active strain was cultivated in a 10-l photobioreactor. Conclusions: Isolation and mass cultivation of Antarctic cyanobacteria and LC-MS (liquid chromatography/mass spectrometry) fractionation of extracts from a subset of those strains (hits) that exhibited relatively potent antibacterial and/or antifungal activities, evidenced a chemical novelty worthy of further investigation. Significance and impact of the study: Development of isolation, cultivation and screening methods for Antarctic cyanobacteria has led to the discovery of strains endowed with interesting antimicrobial and antitumour activities.last_img read more

Resolving the northern hemisphere source region for the long-distance dispersal event that gave rise to the South American endemic dung moss Tetraplodon fuegianus

first_imgPREMISE OF THE STUDY: American bipolar plant distributions characterize taxa at various taxonomic ranks but are most common in the bryophytes at infraspecific and infrageneric levels. A previous study on the bipolar disjunction in the dung moss genus Tetraplodon found that direct long-distance dispersal from North to South in the Miocene–Pleistocene accounted for the origin of the Southern American endemic Tetraplodon fuegianus, congruent with other molecular studies on bipolar bryophytes. The previous study, however, remained inconclusive regarding a specific northern hemisphere source region for the transequatorial dispersal event that gave rise to T. fuegianus. METHODS: To estimate spatial genetic structure and phylogeographic relationships within the bipolar lineage of Tetraplodon, which includes T. fuegianus, we analyzed thousands of restriction-site-associated DNA (RADseq) loci and single nucleotide polymorphisms using Bayesian individual assignment and maximum likelihood and coalescent model based phylogenetic approaches. KEY RESULTS: Northwestern North America is the most likely source of the recent ancestor to T. fuegianus. CONCLUSIONS: Tetraplodon fuegianus, which marks the southernmost populations in the bipolar lineage of Tetraplodon, arose following a single long-distance dispersal event involving a T. mnioides lineage that is now rare in the northern hemisphere and potentially restricted to the Pacific Northwest of North America. Furthermore, gene flow between sympatric lineages of Tetraplodon mnioides in the northern hemisphere is limited, possibly due to high rates of selfing or reproductive isolation.last_img read more

Utah’s Gobert Named NBA All-Defensive First Team

first_imgMay 24, 2018 /Sports News – Local Utah’s Gobert Named NBA All-Defensive First Team Written by Robert Lovell FacebookTwitterLinkedInEmail(Salt Lake City, UT)  —  Jazz center Rudy Gobert is one of five players on the NBA’s All-Defensive First Team.The teams were announced yesterday.  The 25-year-old averaged 2.3 blocks and 10.7 rebounds per game for Utah and served as a dominant rim protector.  This is Gobert’s second straight season earning this honor.Gobert led all players in votes, garnering 192 points with 94 first team votes out of 100 possible. Anthony Davis of the New Orleans Pelicans finished second in the voting and is on the NBA All-Defensive First Team for the first time.Joining Gobert and Davis on the first team are Victor Oladipo of the Indiana Pacers, Pelicans guard Jrue Holiday, and Philadelphia 76ers forward Robert Covington.Three other Jazz players received votes for the NBA All-Defensive teams: Ricky Rubio, Derrick Favors and Donovan Mitchell. Tags: Basketball/NBA/NBA All-Defensive Team/Rudy Gobert/Utah Jazzlast_img read more

Pitcher CC Sabathia credits training regimen for late-career success

first_imgJuly 3, 2018 /Sports News – National Pitcher CC Sabathia credits training regimen for late-career success FacebookTwitterLinkedInEmailScott Clarke/ESPN Images(NEW YORK) — Yankees pitcher CC Sabathia is pitching in the midst of his eighteenth Major League season, and it has been one of his most effective in several years.Sabathia entered the month of July ranked among the top pitchers in the American League in earned run average (ERA), and has kept the Yankees in the running for a division title.Weeks away from his 38th birthday, Sabathia says one of the keys to his late-career success has been his training regimen, a routine he developed while working out with his former teammate, Andy Pettitte.“I think everything late in my career has been after Andy. We worked out a lot together when he was playing, and I was picking his brain on what to do in the offseason from a routine perspective,” Sabathia said in an exclusive conversation with ABC News. “Andy Pettitte has been a great mentor… I’ve watched a lot of video of him the last couple of years, and what he’s turned into the past couple of years, it’s really helped me.”Sabathia was speaking before attending Triple Play Day at the Alfred E. Smith Recreation Center in New York City in late June. As he discussed his season and dedication to fitness with ABC News, he was kicking off a series of nationwide events with the Boys & Girls Clubs to encourage youth development, exercising, and physical health.Sabathia says he has tried boxing in recent years–a newer workout routine for the long time ace, who stands six feet and six inches tall. He says boxing does not put as much stress on his lower body, and he has alternated between other workouts to put less stress on his joints, such as swimming.Shaking up his exercise regimen is not the only change Sabathia made.“Oh no, I’ve completely changed the style I pitched,” Sabathia tells ABC News, when asked whether he adjusted the way he approaches pitching or if he made fewer, subtler changes. Earlier in his career, while he was pitching for the Cleveland Indians, Sabathia says he pitched with a “football mentality,” something he believes he picked up while playing a variety of contact sports with the Boys & Girls Club as a kid. He was a harder thrower, a more aggressive pitcher, and accumulated more strikeouts than he does now.Pitching into his late thirties, Sabathia has had to face the realities of playing baseball as his body fails to move as fast as it once did and does not recover as quickly: “I think it’s just getting around older players and kind of realizing what you need to do to take that next step in your career.”Sabathia first joined the Yankees as a free agent in December 2008, leading New York to their 27th World Series championship in his first year with the team. Now in his tenth season in New York, Sabathia is continuing to develop his workout routine so he can extend his career in hopes of winning another championship and lead a healthy lifestyle long after he is done pitching.Copyright © 2018, ABC Radio. All rights reserved. Beau Lundcenter_img Written bylast_img read more

Australian Open: Serena Williams beats No. 1 Simona Halep to advance

first_imgJanuary 21, 2019 /Sports News – National Australian Open: Serena Williams beats No. 1 Simona Halep to advance FacebookTwitterLinkedInEmailFred Lee/Getty Images(MELBOURNE, Australia) — Serena Williams advanced to the quarterfinals of the Australian Open on Monday after defeating the No. 1-seeded Simona Halep.Williams, 37, beat the 27-year-old Romanian player 6-1, 4-6, 6-4. The American tennis star will now go on to face the Czech Republic’s Karolina Pliskova in the quarterfinals. Williams is hoping to win her eighth Australian Open title and her 24th Grand Slam tournament overall. She last took home the trophy in Melbourne in 2017 while she was pregnant.Copyright © 2019, ABC Radio. All rights reserved. Written bycenter_img Beau Lundlast_img read more

Nationals return to DC as World Series champs

first_img Beau Lund Written by FacebookTwitterLinkedInEmailmiflippo/iStock(WASHINGTON) — The Washington Nationals are back home after winning the World Series in Houston Wednesday.The first-time champions landed in Dulles International Airport Thursday night and are gearing up to celebrate their victory this weekend.A parade will be held for the Nats in the nation’s capital on Saturday, beginning at 2 p.m. For more on the parade route and celebration, watch the video below:Copyright © 2019, ABC Audio. All rights reserved.center_img November 1, 2019 /Sports News – National Nationals return to DC as World Series champslast_img read more

Lions trade cornerback Slay to Eagles

first_imgMarch 19, 2020 /Sports News – National Lions trade cornerback Slay to Eagles FacebookTwitterLinkedInEmailJustin Edmonds/Getty Images(DETROIT) — The Lions have traded pro bowl cornerback Darius Slay to the Eagles for a third round and fifth round pick in this years draft, according to ESPN NFL Insider Adam Schefter. Slay’s agent Drew Rosenhaus told ESPN the two sides have agreed to a three year, 50 million dollar deal.The 29 year-old will become the highest paid cornerback in the league based on the annual average of the deal, which is 16.67 million dollars. His contract just beat out Miami’s Byron Jones, who signed a five year, 82.5 million dollar deal that averages 16.50 million dollars a year. A star cornerback was one of the biggest needs for Philadelphia this offseason.Last year, the Eagles allowed 15 pass plays of 40 yards of more, the second most in the NFL. Slay was drafted by Detroit out of Mississippi State in the second round in 2013. He recorded 19 interceptions and 103 passes defended during his seven years with the team and made the Pro Bowl each of the past three seasons. Copyright © 2020, ABC Audio. All rights reserved. Beau Lundcenter_img Written bylast_img read more

Vanessa Bryant says Kobe wanted to use retirement to ‘make up for lost time’

first_img Beau Lund FacebookTwitterLinkedInEmailRob Carr/Getty Images(LOS ANGELES) — To mark Mamba Day, the fourth anniversary of Kobe Bryant’s final NBA game, his widow, Vanessa Bryant, shared footage of his final moments on the court.In her caption, Vanessa Bryant reflected on the “senseless” deaths of her husband and their daughter, 13-year-old Gianna, who were killed in a helicopter crash in January.Noting that the NBA legend, nicknamed “The Black Mamba,” “worked his ass off for 20 years,” she explained that he’d hoped to use his retirement to focus on family.“All he wanted was to spend time with our girls and me to make up for lost time,” she wrote. “He wanted to be there for every single milestone and special moment in our girls’ lives.”Kobe Bryant, 42, and Gianna — known as Gigi — were among the nine victims killed in a helicopter crash on Jan. 26 in Southern California. At the time, they were en route to a basketball game at Bryant’s Mamba Academy.Like her famous father, Gigi loved to play basketball, and, according to Vanessa Bryant, “she worked hard and gave her all 7 days a week just like her daddy.”“He only got to enjoy 3 years and 9 months of retirement. We had 2 more daughters, he won an Oscar, he opened Granity studios, he became a 5x best selling author and coached Gianna’s basketball team in that time,” Vanessa Bryant wrote. “I wish I could back to that morning, every day. I wish they had a normal local game on 1/26. Life truly isn’t fair.”Kobe Bryant is survived by his wife and three daughters: Natalia, 17, Bianka, 3, and Capri, 9 months.Copyright © 2020, ABC Audio. All rights reserved. April 14, 2020 /Sports News – National Vanessa Bryant says Kobe wanted to use retirement to ‘make up for lost time’center_img Written bylast_img read more