The third Canadian Arctic Human Health Assessment conducted under the Canadian Northern Contaminants Program (NCP), in association with the circumpolar Arctic Monitoring and Assessment Programme ...(AMAP), addresses concerns about possible adverse health effects in individuals exposed to environmental contaminants through a diet containing country foods. The objectives here are to: 1) provide data on changes in human contaminant concentrations and exposure among Canadian Arctic peoples; 2) identify new contaminants of concern; 3) discuss possible health effects; 4) outline risk communication about contaminants in country food; and 5) identify knowledge gaps for future contaminant research and monitoring. The nutritional and cultural benefits of country foods are substantial; however, some dietary studies suggest declines in the amount of country foods being consumed. Significant declines were found for most contaminants in maternal blood over the last 10
years within all three Arctic regions studied. Inuit continue to have the highest levels of almost all persistent organic pollutants (POPs) and metals among the ethnic groups studied. A greater proportion of people in the East exceed Health Canada's guidelines for PCBs and mercury, although the proportion of mothers exceeding these guidelines has decreased since the previous assessment. Further monitoring and research are required to assess trends and health effects of emerging contaminants. Infant development studies have shown possible subtle effects of prenatal exposure to heavy metals and some POPs on immune system function and neurodevelopment. New data suggest important beneficial effects on brain development for Inuit infants from some country food nutrients. The most successful risk communication processes balance the risks and benefits of a diet of country food through input from a variety of regional experts and the community, to incorporate the many socio-cultural and economic factors to arrive at a risk management decision that will be the most beneficial in Arctic communities.
Following a lightning strike to a wind turbine in Japan, we have observed a large burst of neutrons lasting 100 ms with a ground fluence of ~1,000 n cm−2, thousands of times greater than the peak ...neutron flux associated with the largest ground level solar particle event ever observed. This is the first detection of an unequivocal signature of neutrons from a terrestrial gamma ray flash, consisting of a 2.223 MeV gamma‐ray spectral line from a neutron‐capture on hydrogen reaction occurring in our detector, and is shown to be consistent with the production of 1012–1013 photoneutrons from a downward terrestrial gamma ray flash (TGF) at 1.0 km, with a gamma ray brightness typical of upward TGFs observed by satellites.
Key Points
Gamma rays producing a neutron flash with a ground fluence of 1,000 n cm−2 and 100 ms duration was observed following a lightning strike
This observation is consistent with simulations of photoneutron production from a terrestrial gamma ray flash (TGF) with typical brightness
These measurements definitively show that low altitude atmospheric electricity can drive nuclear processes
Plain Language Summary
Using detectors to measure gamma‐rays, we have observed a cloud of neutrons following a lightning strike to a wind turbine in Japan.
The Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) studies the loss of energetic electrons from Earth's radiation belts. BARREL's array of slowly drifting balloon payloads was ...designed to capitalize on magnetic conjunctions with NASA's Van Allen Probes. Two campaigns were conducted from Antarctica in 2013 and 2014. During the first campaign in January and February of 2013, there were three moderate geomagnetic storms with SYM‐Hmin < −40 nT. Similarly, two minor geomagnetic storms occurred during the second campaign, starting in December of 2013 and continuing on into February of 2014. Throughout the two campaigns, BARREL observed electron precipitation over a wide range of energies and exhibiting temporal structure from hundreds of milliseconds to hours. Relativistic electron precipitation was observed in the dusk to midnight sector, and microburst precipitation was primarily observed near dawn. In this paper we review the two BARREL science campaigns and discuss the data products and analysis techniques as applied to relativistic electron precipitation observed on 19 January 2013.
Key Points
BARREL observed electron precipitation over wide range of energy and timescales
Precipitating electron distribution is determined using spectroscopy for 19 January 2013 event
BARREL timing data has accuracy within sampling interval of 0.05 s
On 23 October 2015 at ~1732 UTC, the Airborne Detector for Energetic Lightning Emissions (ADELE) flew through the eyewall of Hurricane Patricia aboard National Oceanic and Atmospheric ...Administration's Hurricane Hunter WP‐3D Orion, observing the first terrestrial gamma‐ray flash (TGF) ever seen in that context, and the first ever viewed from behind the forward direction of the main TGF gamma‐ray burst. ADELE measured 184 counts of ionizing radiation within 150 μs, coincident with the detection of a nearby lightning flash. Lightning characteristics inferred from the associated radio signal and comparison of the gamma‐ray energy spectrum to simulations suggests that this is the first observation of a reverse beam of positrons predicted by the leading TGF production model, relativistic runaway electron avalanches. This paper presents the first experimental evidence of a previously predicted second component of gamma‐ray emission from TGFs. The brightest emission, commonly observed from orbit, is from the relativistic runaway electron avalanche bremsstrahlung; the second, fainter component reported here is from the bremsstrahlung of positrons propagating in the reverse direction. This reverse gamma‐ray beam penetrates to low enough altitudes to allow ground‐based detection of typical upward TGFs from mountain observatories.
Plain Language Summary
We report the first observation of gamma‐ray emission from lightning within a hurricane eyewall, consistent with production by a downward beam of positrons.
Key Points
We report the first in situ observation of a terrestrial gamma‐ray flash inside a hurricane eyewall
Observed gamma‐ray spectra, lightning data, and meteorological scenario are consistent with production of a downward beam of positrons
Simulations of the downward positron beam establish ordinary TGFs as detectable at almost any altitude
An on‐ground observation program for high‐energy atmospheric phenomena in winter thunderstorms along the Japan Sea has been performed via measurements of gamma ray radiation, atmospheric electric ...field, and low‐frequency radio band. On 11 February 2017, the radiation detectors recorded gamma ray emission lasting for 75 s, and then abruptly terminated with a nearby lightning discharge. The gamma ray spectrum extended up to 20 MeV and was reproduced by a cutoff power law model with a photon index of
1.36−0.04+0.03, being consistent with Bremsstrahlung radiation from a thundercloud (known as a gamma‐ray glow or a thunderstorm ground enhancement). The low‐frequency radio monitors, installed ∼50 km away from the gamma ray observation site recorded leader development of an intracloud/intercloud discharge spreading over ∼60 km area with a ∼300‐ms duration. The timing of the gamma ray termination coincided with the moment when the leader development of the intracloud/intercloud discharge passed 0.7 km horizontally away from the radiation monitors. The intracloud/intercloud discharge started ∼15 km away from the gamma ray observation site. Therefore, the glow was terminated by the leader development, while it did not trigger the lightning discharge in the present case.
Plain Language Summary
This study presents high‐energy radiation, atmospheric electric field and low‐frequency radio measurements of winter thunderstorms in Japan. Long‐duration gamma ray bursts, called “gamma ray glows,” are thought to originate from electrons accelerated and multiplied by strong electric fields in thunderclouds. There are unsolved questions such as electron‐acceleration mechanisms, position of the acceleration site, lifetime, and life cycle of the bursts. We observed a gamma ray burst lasting for ∼75 s from a thundercloud abruptly terminated with a lightning discharge. The gamma ray source was destroyed by a cloud‐to‐cloud discharge over the gamma ray observation site but not related to the triggering of the discharge in the present case.
Key Points
A gamma ray glow and its termination with a lightning discharge was observed in a Japanese winter thunderstorm
The glow was terminated by leader development of a horizontally long intracloud/intercloud discharge passing nearby overhead
The intracloud/intercloud discharge was not triggered by the glow in the present case because it started far from the gamma ray glow site
We report on the acceleration of ion beams from ultrathin diamondlike carbon foils of thickness 50, 30, and 10 nm irradiated by ultrahigh contrast laser pulses at intensities of approximately 7 x ...10;{19} W/cm;{2}. An unprecedented maximum energy of 185 MeV (15 MeV/u) for fully ionized carbon atoms is observed at the optimum thickness of 30 nm. The enhanced acceleration is attributed to self-induced transparency, leading to strong volumetric heating of the classically overdense electron population in the bulk of the target. Our experimental results are supported by both particle-in-cell (PIC) simulations and an analytical model.
After every other failure mode has been considered, in the end, the high-performance limit of all lasers is set by optical damage. The demands of inertial confinement fusion (ICF) pushed lasers ...designed as ICF drivers into this limit from their very earliest days. The first ICF lasers were small, and their pulses were short. Their goal was to provide as much power to the target as possible. Typically, they faced damage due to high intensity on their optics. As requests for higher laser energy, longer pulse lengths, and better symmetry appeared, new kinds of damage also emerged, some of them anticipated and others unexpected. This paper will discuss the various types of damage to large optics that had to be considered, avoided to the extent possible, or otherwise managed as the National Ignition Facility (NIF) laser was designed, fabricated, and brought into operation. It has been possible for NIF to meet its requirements because of the experience gained in previous ICF systems and because NIF designers have continued to be able to avoid or manage new damage situations as they have appeared.
It has been reported that the laparoscopic repair of paraesophageal hernias is associated with higher complication and recurrence rates than the open methods of repair.
We identified 136 consecutive ...patients who underwent laparoscopic repair of a paraesophageal hernia between 1993 and 1999. Patient demographics and symptom scores for regurgitation, heartburn, chest pain, and dysphagia at presentation and at last follow-up were recorded (0 = none, 1 = mild, 2 = moderate, 3 = severe). The operative records were reviewed, and early and late complications were noted. Only patients with a follow-up of >1 were included in the analysis.
The median age was 64 years, and there was a female preponderance (1.8:1). Most patients had some medical comorbidity; the American Society of Anesthesiologists (ASA) scores were <2 in eight patients and ?2 in 117 patients. Three laparoscopic operations were converted to open procedures. There were nine intraoperative complications, five early complications, and three related deaths (morbidity and mortality rates of 10.2% and 2.2%, respectively). Follow-up data were available for 83 patients (66%), and the mean follow-up time was 40 months (range, 12-82). The percentage of patients experiencing chest pain, dysphagia, heartburn, and regurgitation in the moderate to severe range dropped from a range of 34-47% to 5-7% (p <0.05). Three patients underwent repeat laparoscopic repair for symptomatic recurrence.
The laparoscopic repair of paraesophageal hernias provides excellent long-term symptomatic relief in the majority of patients and has a low rate of symptomatic recurrence. The complication and death rates may be related in part to the higher incidence of comorbidities in this somewhat elderly patient population.
BARREL is a multiple-balloon investigation designed to study electron losses from Earth’s Radiation Belts. Selected as a NASA Living with a Star Mission of Opportunity, BARREL augments the Radiation ...Belt Storm Probes mission by providing measurements of relativistic electron precipitation with a pair of Antarctic balloon campaigns that will be conducted during the Austral summers (January-February) of 2013 and 2014. During each campaign, a total of 20 small (∼20 kg) stratospheric balloons will be successively launched to maintain an array of ∼5 payloads spread across ∼6 hours of magnetic local time in the region that magnetically maps to the radiation belts. Each balloon carries an X-ray spectrometer to measure the bremsstrahlung X-rays produced by precipitating relativistic electrons as they collide with neutrals in the atmosphere, and a DC magnetometer to measure ULF-timescale variations of the magnetic field. BARREL will provide the first balloon measurements of relativistic electron precipitation while comprehensive in situ measurements of both plasma waves and energetic particles are available, and will characterize the spatial scale of precipitation at relativistic energies. All data and analysis software will be made freely available to the scientific community.
Four new simple sequence repeat (SSR) loci (designated VVMD5, VVMD6, VVMD7, and VVMD8) were characterized in grape and analyzed by silver staining in 77 cultivars of Vitis vinifera. Amplification ...products ranged in size from 141 to 263 base pairs (bp). The number of alleles observed per locus ranged from 5 to 11 and the number of diploid genotypes per locus ranged from 13 to 27. At each locus at least 75% of the cultivars were heterozygous. Alleles differing in length by only 1 bp could be distinguished by silver staining, and size estimates were within 1 or 2 bp, depending on the locus, of those obtained by fluorescence detection at previously reported loci. Allele frequencies were generally similar in wine grapes and table grapes, with some exceptions. Some alleles were found only in one of the two groups of cultivars. All 77 cultivars were distinguished by the four loci with the exception of four wine grapes considered to be somatic variants of the same cultivar, 'Pinot noir', 'Pinot gris', 'Pinot blanc', and 'Meunier'; two table grapes that are known to be synonymous, 'Keshmesh' and 'Thompson Seedless'; and three table grapes, 'Dattier', 'Rhazaki Arhanon', and 'Markandi', the first two of which have been suggested to be synonymous. Although the high polymorphism at grape SSR loci suggests that very few loci would theoretically be needed to separate all cultivars, the economic and legal significance of grape variety identification requires the increased resolution that can be provided by a larger number of loci. The ease with which SSR markers and data can be shared internationally should encourage their broad use, which will in turn increase the power of these markers for both identification and genetic analysis of grape.
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