Effect of phototherapy on serum 25-hydroxyvitamin D in the Antarctic

first_imgThe hypothesis that sunlight may induce the enzymes involved in the vitamin D pathway has been tested by comparing the ability to synthesize vitamin D3 and its 25 hydroxy metabolite (25-OHD) in 2 groups of male volunteers resident at the British Antarctic base at Rothera Point (67° 34′ S.). One group endured the UV depleted winter and the other group received regular phototherapy throughout the winter. Both groups then received a course of 14 days phototherapy in October (Southern Hemisphere spring). The group receiving regular phototherapy had a trend towards a higher level of serum 25-OHD, and the October phototherapy course produced a further small increase in serum 25-OHD values. In the previously non irradiated group the October phototherapy produced a much larger increase in serum 25-OHD so that they attained the previously higher values of the pre-iradiated group. There was a negative correlation between the pre October phototherapy serum concentration of 25-OHD and the subsequent increment (r−0.78,p<0.01) but no relationship between the serum 25-OHD and D3 after phototherapy. These results provide evidence against the existence of enzyme induction of vitamin D 25 hydroxylase by light.last_img read more

Individual variation in the duration of pregnancy and birth date in Antarctic fur seals: the role of environment, age, and sex of fetus

first_imgThe duration of 506 pregnancies in Antarctic fur seals (Arctocephalus gazelld) was measured 1983–1993. On average, pregnancy lasted 359 days, with a range of 340–390 days, representing 20% of the period of post-implantation fetal growth. Pregnancy was longest and birth dates latest in years associated with reduced availability of food. Sex of fetus and birth mass had no effect on the duration of pregnancy or date of birth. However, dates of parturition tended to be consistent within individuals.last_img

Mafic dike swarms in the South Shetland Islands volcanic arc: Unravelling multiepisodic magmatism related to subduction and continental rifting

first_imgEight groups of mafic dikes and related high-level stocks cut Triassic accretionary complex and Mesozoic magmatic arc formations on Livingston Island. Some are affected by silicic/sericitic alteration, related to Cretaceous hydrothermal activity, and propylitic/epidosite alteration, analogous to that in ocean floor sheeted dikes. Alteration was accompanied by major and trace element metasomatism. Ar-Ar analysis of the freshest rocks indicates five intrusive events, some of which are unexpectedly young. Groups 1–3 were intruded in the mid to late Cretaceous (∼108–74 Ma) and were coeval with the calc-alkaline arc. Between 70 and 50 Ma, relatively rapid and oblique plate convergence led to strike-slip tectonism and a pause in magmatism. At ∼52 Ma, orthogonal, slow convergence resulted in extensional faulting and emplacement of calc-alkaline (group 2) and primitive tholeiitic dikes (groups 4–6) between 51 and 45 Ma. Extension of Antarctic Peninsula-southern South American crust culminated in emplacement of mafic to intermediate, medium-grained plutons and group C porphyries between 44 and 36 Ma. Localized hydrothermal flow along fault zones resulted in partial to complete argon loss from nearby Cretaceous lavas and Ar-Ar reset ages of ∼40 Ma in mid-Cretaceous hydrothermal K-feldspar. Primitive olivine basalts (group D) and epithermal carbonate veins (31–29 Ma) were emplaced during along-arc extension accompanying the opening of Drake Passage and Powell Basin. Excess argon occurs in two forms: strongly held in melt? inclusions in the primitive tholeiites and weakly held in some secondary alteration. There is no radiometric evidence, in the area studied, for magmatism related to late Cenozoic subduction, nor to the Pleistocene-Recent opening of the back arc Bransfield rift.last_img read more

Hibernation in an Antarctic fish: on ice for winter

first_imgActive metabolic suppression in anticipation of winter conditions has been demonstrated in species of mammals, birds, reptiles and amphibians, but not fish. This is because the reduction in metabolic rate in fish is directly proportional to the decrease in water temperature and they appear to be incapable of further suppressing their metabolic rate independently of temperature. However, the Antarctic fish (Notothenia coriiceps) is unusual because it undergoes winter metabolic suppression irrespective of water temperature. We assessed the seasonal ecological strategy by monitoring swimming activity, growth, feeding and heart rate (f(H)) in N. coriiceps as they free-ranged within sub-zero waters. The metabolic rate of wild fish was extrapolated from f(H) recordings, from oxygen consumption calibrations established in the laboratory prior to fish release. Throughout the summer months N. coriiceps spent a considerable proportion of its time foraging, resulting in a growth rate (G(w)) of 0.18 +/- 0.2% day(-1). In contrast, during winter much of the time was spent sedentary within a refuge and fish showed a net loss in Gw (-0.05 +/- 0.05% day(-1)). Whilst inactive during winter, N. coriiceps displayed a very low fH, reduced sensory and motor capabilities, and standard metabolic rate was one third lower than in summer. In a similar manner to other hibernating species, dormancy was interrupted with periodic arousals. These arousals, which lasted a few hours, occurred every 4-12 days. During arousal activity, f(H) and metabolism increased to summer levels. This endogenous suppression and activation of metabolic processes, independent of body temperature, demonstrates that N. coriiceps were effectively ‘putting themselves on ice’ during winter months until food resources improved. This study demonstrates that at least some fish species can enter a dormant state similar to hibernation that is not temperature driven and presumably provides seasonal energetic benefits.last_img read more

Initial results from light level geolocator trials on Ruddy Turnstone Arenaria interpres reveal unexpected migration route

first_imgWith the development of archival light level geolocators weighing only 1 g, their deployment on medium sizewaders is now possible. Trials showed that attachment via leg flag rather than backpack harness was preferablebecause of the large weight gains of Ruddy Turnstone during preparation for migration. Geolocators attachedto leg flags were fitted to six Ruddy Turnstones at Flinders, Victoria, SE Australia, and four were retrievedthe following season. All four birds had made an initial non-stop 7,600 km flight, in six days, to Taiwan, withthree probably travelling in the same flock. Individuals then followed separate paths through E Asia beforelocations became indiscernible in early June in E Siberia as birds encountered continuous daylight. Brief datawere recorded for two birds at the beginning of southward migration through E Siberia in early August beforethe damaged light sensor stalk on the geolocator failed, as another had also done on the breeding grounds.The fourth bird, without a stalked light sensor in its geolocator, was in the Aleutian Islands, SW Alaska, whenlocations again became discernible on 26 July. It remained there until 15 October and then made a 6,200 kmnon-stop flight to the Gilbert Islands, western central Pacific in four days. After another prolonged stopoverit departed on 29 November reaching E Australia in four days (5,000 km) and arrived back at Flinders on8 December. This bird had made a round trip migration of around 27,000 km. Between 26 June and 14 July,when it was in the Arctic, the light data record of this bird suggested that it had been incubating. A further 60geolocators will be deployed on Ruddy Turnstones in SE Australia in March/April 2010.last_img read more

A distributed lag-autoregressive model of geostationary relativistic electron fluxes: comparing the influences of waves, seed and source electrons, and solar wind inputs

first_imgRelativistic electron flux at geosynchronous orbit depends on enhancement and loss processes driven by ULF Pc5, chorus, and EMIC waves, seed electron flux, magnetosphere compression, the “Dst effect”, and substorms, while solar wind inputs such as velocity, number density, and IMF Bz drive these factors and thus correlate with flux. Distributed lag regression models show the time delay of highest influence of these factors on log10 high energy electron flux (0.7 – 7.8 MeV, LANL satellites). Multiple regression with an autoregressive term (flux persistence) allows direct comparison of the magnitude of each effect while controlling other correlated parameters. Flux enhancements due to ULF Pc5 and chorus waves are of equal importance. The direct effect of substorms on high energy electron flux is strong, possibly due to injection of high energy electrons by the substorms themselves. Loss due to EMIC waves is less influential. Southward Bz shows only moderate influence when correlated processes are accounted for. Adding covariate compression effects (pressure and IMF magnitude) allows wave‐driven enhancements to be more clearly seen. Seed electrons (270 keV) are most influential at lower relativistic energies, showing that such a population must be available for acceleration. However, they are not accelerated directly to the highest energies. Source electrons (31.7 keV) show no direct influence when other factors are controlled. Their action appears to be indirect via the chorus waves they generate. Determination of specific effects of each parameter when studied in combination will be more helpful in furthering modelling work than studying them individually.last_img read more

Sub-Antarctic freshwater invertebrate thermal tolerances: an assessment of critical thermal limits and behavioral responses

first_imgPhysiological thermal limits of organisms are linked to their geographic distribution. The assessment of such limits can provide valuable insights when monitoring for environmental thermal alterations. Using the dynamic critical thermal method (CTM), we assessed the upper (CTmax) and lower (CTmin) thermal limits of three freshwater macroinvertebrate taxa with restricted low elevation distribution (20 m a.s.l.) and three taxa restricted to upper elevations (480 and 700 m a.s.l.) in the Magellanic sub-Antarctic ecoregion of southern Chile. In general terms, macroinvertebrates restricted to lower altitudinal ranges possess a broader thermal tolerance than those restricted to higher elevations. Upper and lower thermal limits are significantly different between taxa throughout the altitudinal gradient. Data presented here suggest that freshwater macroinvertebrates restricted to upper altitudinal ranges may be useful indicators of thermal alteration in their habitats, due to their relatively low tolerance to increasing temperatures and the ease with which behavioral responses can be detected.last_img read more

New England Patriots star thanks Instagram follower who helped him thwart school shooting plot

first_img Written by April 6, 2018 /Sports News – National New England Patriots star thanks Instagram follower who helped him thwart school shooting plot FacebookTwitterLinkedInEmailJoe Faraoni/ESPN Images(BOSTON) — NFL star Julian Edelman made an incredible catch off the field when he helped authorities thwart a potential high school shooting plot thanks to a tip on Instagram. “At first I was like, ‘I don’t know if this is real,’” Edelman, a wide receiver with the New England Patriots, said in an exclusive interview on Good Morning America about the initial message. In March, Edelman received a direct message from one of his Instagram followers alerting him of a comment posted on Edelman’s Instagram account. The message threatened to shoot up a school.“Dude,” the Instagram user wrote. “There is a kid in your comment section, says he [is] going to shoot up a school. I think you should alert the authority.”Edelman said he called his assistant, Shannen Moen, who was in Boston.“I said, ‘Check this out. See what’s going on with this. We’ve got to do something about this,’” Edelman said.Moen told GMA she moved quickly and gathered as much evidence for authorities as possible.“My initial thought was, my heart just sunk,” Moen said. “And I first thought I need to go and find the comment, locate it. I did. I took screenshots of everything. I immediately called 911.”Local authorities in Boston immediately called police in Michigan, where the user was then located and identified as a 14-year-old high school student. “Boston PD reached out to our department. Our on-duty supervisors immediately started looking into the information that was provided,” said Capt. Joe Platzer of the Port Huron Police Department in Michigan. “We take these threats very seriously. We look into them very thoroughly. Like we tell everybody, if you see something, if you hear something, say something.”According to Platzer, police traced the message back to a 14-year-old boy in Port Huron. He said the teen was brought in for questioning and admitted to writing the threat.Police also said they found two rifles in the teen’s home that belonged to his mother.“It’s scary to think that those types of things can happen at a place of learning and a place where kids are going just to grow up in and meet with people and get social skills. I’d say that’s a scary thing,” Edelman said.The teen, whom police have not identified, was arrested and charged with making a false report of a threat of terrorism, which is a felony in Michigan.According to Platzer, Port Huron detectives spoke to Edelman and credited him with bringing the threat forward. Without Edelman’s reaction to the alarming social media post, police said, it’s likely they would not have known about the threat. But Edelman said the credit should go to the follower who alerted him about the threat and his assistant.“I just want to say thank you for being the awesome human being that you are,” the NFL star said in a message to the follower. “Keep on scouring, keep on going over all the comments. You’re like the comment police, bro. We appreciate you.”Copyright © 2018, ABC Radio. All rights reserved.center_img Beau Lundlast_img read more

Ashley Gill Joins USU Women’s Basketball Staff

first_img Brad James Tags: Ashley Gill/Pacific Pipeline/USU Women’s Basketball/Washington State May 4, 2018 /Sports News – Local Ashley Gill Joins USU Women’s Basketball Staff Written by FacebookTwitterLinkedInEmailLOGAN, Utah-Thursday, Utah State women’s basketball added a new assistant coach, per an announcement from head coach Jerry Finkbeiner.Ashley Gill comes to the USU women’s basketball program after a nine-year stint on Washington State’s women’s basketball staff.Gill spent three seasons as the Cougars’ team manager and video coordinator before being named an assistant coach in Pullman, Wash. prior to the 2012-13 season.Gill primary excelled on the Cougars’ staff as the recruiting coordinator, which blesses the Aggies’ staff with her international connections.While at Washington State, Gill’s specialty was recruiting the “Pacific pipeline,” consisting of connections from Australia and Hawaii, primarily.Incidentally, the Aggies already have a foothold in Australia as there are currently 5 USU players on the roster from the Land Down Under.During Gill’s time on the staff at Washington State, the Cougars made the WNIT three times, advancing to the semifinals at the end of the 2016-17 season.Gill boasts a pair of degrees from Washington State, graduating in 2009 with a bachelor’s in psychology with a focus in sports management and a master’s degree in sport management.Gill is a native of Brier, Wash. and attended Mountlake Terrace High School, lettering in basketball, volleyball and track.Gill stated that she “cannot wait to get to Logan and continue building on their [Utah State’s] success.”last_img read more

UVU Women’s Soccer Releases 2018 Schedule

first_img FacebookTwitterLinkedInEmailOREM, Utah-Monday, Utah Valley women’s soccer released its 2018 schedule, per a release on gouvu.com.The Wolverines’ schedule features matches against California, Weber State, UNLV, San Diego, Portland, Oklahoma and BYU.In remarking on the schedule, Wolverines women’s head coach Chris Lemay stated “we want to be in the biggest environments and play the best teams.”The Wolverines will play seven of their first nine matches on the road, including the season opener, August 17 at California of the Pac-12 conference.This match serves as homecoming for Lemay as was the Golden Bears’ assistant coach from 2012-16.Utah Valley next faces Wyoming at Laramie, Wyo. on August 19.The home opener will be August 22 when the Wolverines entertain in-state rival Weber State. Additionally, Utah Valley hosts Big 12 foe Oklahoma September 15, marking only the second time the Wolverines have hosted a Big 12 school. Incidentally, Utah Valley leads Oklahoma 1-0 all-time, vanquishing the Sooners at Norman, Okla. in 2016.The conference schedule for Utah Valley commences September 28 at Las Cruces, N.M. against New Mexico State. The conference home opener is a date with Chicago State on October 5.The Wolverines will also host the WAC Tournament October 31-November 4, commemorating the first time in history UVU has hosted the conference tournament.Presently, the Wolverines are on their first-ever international trip in Costa Rica, and will play the Costa Rican national team on May 15. This match will be streamed live on Facebook at GoUVU. Brad James Written by Tags: Chris Lemay/Oklahoma/Utah Valley Women’s Soccer/WAC Sports/Wyoming May 7, 2018 /Sports News – Local UVU Women’s Soccer Releases 2018 Schedulelast_img read more