Spatial and temporal variation in greenhouse gas emissions from two open water prairie wetlands

Prairie wetlands provide valuable habitat for waterfowl and wildlife and buffer the impacts of upland land uses. Their contribution to Canada’s greenhouse gas inventory is poorly understood. The purpose of this study was to compare the spatial and temporal variation in nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) emissions from Pond 1 at the St. Denis Wildlife Management Area, Saskatchewan and the Deep Crop Wetland (DCW) at the Manitoba Zero Tillage Research Association farm, Manitoba. Nitrous oxide flux was low on all measurements days: at Pond 1 flux ranged from -1.47 to 6.01 ng N2O-N m-2 s-1 in 2004 and -6.98 to 5.74 ng N2O-N m-2 s-1 in 2005 and flux from the DCW never exceeded 2.50 ng N2O-N m-2 s-1 in 2005. Methane flux from Pond 1 was substantially higher in 2005 (-469.10 to 3776.08 µmol CH4 m-2 d-1) than in 2004 (-251.55 to 191.55 µmol CH4 m-2 d-1). This increase in methane from Pond 1 followed a major increase in water volume in 2005 after snowmelt. Methane flux in 2005 from the open water and riparian sampling points at the DCW ranged from -13.64 to 110.47 µmol CH4 m-2 d-1 and -4.51 to 40.23 µmol CH4 m-2 d-1, respectively. Carbon dioxide flux from Pond 1 and the DCW in 2005 were very similar: open water flux ranged from -96.42 to 95.42 mmol CO2 m-2 d-1 at Pond 1 and 3.21 to 38.94 mmol CO2 m-2 d-1 at the DCW. Despite the similarity in CO2 flux, the DCW had 10- to 15-fold higher levels of macrophytes, phytoplankton and metaphyton biomass and similar levels of periphyton to Pond 1 in 2005. These biomass differences were not, however, reflected in the CO2 or CH4 flux. Pond 1 and the DCW were net sources for greenhouse gases but contributed less greenhouse gas than reports from other aquatic systems

Performance of a Large-area GEM Detector Read Out with Wide Radial Zigzag Strips

A 1-meter-long trapezoidal Triple-GEM detector with wide readout strips was tested in hadron beams at the Fermilab Test Beam Facility in October 2013. The readout strips have a special zigzag geometry and run along the radial direction with an azimuthal pitch of 1.37 mrad to measure the azimuthal phi-coordinate of incident particles. The zigzag geometry of the readout reduces the required number of electronic channels by a factor of three compared to conventional straight readout strips while preserving good angular resolution. The average crosstalk between zigzag strips is measured to be an acceptable 5.5%. The detection efficiency of the detector is (98.4+-0.2)%. When the non-linearity of the zigzag-strip response is corrected with track information, the angular resolution is measured to be (193+-3) urad, which corresponds to 14% of the angular strip pitch. Multiple Coulomb scattering effects are fully taken into account in the data analysis with the help of a stand-alone Geant4 simulation that estimates interpolated track errors.Comment: 30 pages, 28 figures, submitted to NIM

Foraging Behaviours of Wolverines at a Large Arctic Goose Colony

At the large Ross's goose and lesser snow goose colony at Karrak Lake, Nunavut, Canada, we saw wolverines kill two geese, take 13 eggs from 12 goose nests, and take three goose carcasses from two fox dens. Wolverines also made unsuccessful attempts to capture geese and frequently ignored eggs from nests where geese had fled the approaching wolverine. Most foods (all geese killed by wolverines and 80% of the eggs) were cached for later use, whereas few foods were eaten immediately (20% of the eggs and part of a goose taken from a fox den, which was later lost) or lost (all geese taken from fox dens). Wolverines spent little time caching foods (e.g., some foods were never covered), which suggests that recovery of these foods was not crucial to wolverines. When taking foods from fox dens, wolverines were mobbed by foxes; as a result, only one wolverine managed to consume part of a goose carcass taken from a fox den. These observations illustrate the opportunistic nature of wolverines and suggest that their scavenging success may be influenced by how well foods are defended.À l'importante colonie d'oies de Ross et de petites oies des neiges située à Karrak Lake au Nunavut (Canada), on a vu des carcajous tuer deux oies, prendre 13 oeufs dans 12 nids d'oies, et prendre trois carcasses d'oies dans deux terriers de renards. Les carcajous ont aussi essayé, sans succès, de capturer des oies et ils ignoraient souvent les oeufs des nids que les oies avaient fuis à leur approche. La plupart des aliments (toutes les oies tuées par les carcajous et 80 p. cent des oeufs) étaient dissimulés pour utilisation ultérieure, tandis que peu d'aliments étaient consommés tout de suite (20 p. cent des oeufs et une partie d'une oie prélevée dans un terrier de renard, qui a été perdue par la suite) ou perdus (toutes les oies prises dans les terriers de renards). Les carcajous passaient peu de temps à dissimuler les aliments (p. ex., certains n'étaient jamais recouverts), ce qui suggère qu'il n'est pas crucial pour eux de les retrouver. Quand les carcajous prenaient des aliments dans les terriers de renards, ils étaient assaillis par les occupants; en conséquence, un seul carcajou est parvenu à consommer une partie d'une carcasse d'oie prise dans un terrier de renard. Ces observations illustrent la nature opportuniste des carcajous et suggèrent que leur succès de récupération pourrait être influencé par la façon dont les aliments sont défendus

Mammographic density and risk of breast cancer by age and tumor characteristics

Introduction: Understanding whether mammographic density (MD) is associated with all breast tumor subtypes and whether the strength of association varies by age is important for utilizing MD in risk models. Methods: Data were pooled from six studies including 3414 women with breast cancer and 7199 without who underwent screening mammography. Percent MD was assessed from digitized film-screen mammograms using a computer-assisted threshold technique. We used polytomous logistic regression to calculate breast cancer odds according to tumor type, histopathological characteristics, and receptor (estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER2)) status by age (51%) versus average density (11-25%). Women ages 2.1 cm) versus small tumors and positive versus negative lymph node status (P’s < 0.01). For women ages <55 years, there was a stronger association of MD with ER-negative breast cancer than ER-positive tumors compared to women ages 55–64 and ≥65 years (Page-interaction = 0.04). MD was positively associated with both HER2-negative and HER2-positive tumors within each age group. Conclusion: MD is strongly associated with all breast cancer subtypes, but particularly tumors of large size and positive lymph nodes across all ages, and ER-negative status among women ages <55 years, suggesting high MD may play an important role in tumor aggressiveness, especially in younger women

Identifying colorectal cancer caused by biallelic MUTYH pathogenic variants using tumor mutational signatures

Carriers of germline biallelic pathogenic variants in the MUTYH gene have a high risk of colorectal cancer. We test 5649 colorectal cancers to evaluate the discriminatory potential of a tumor mutational signature specific to MUTYH for identifying biallelic carriers and classifying variants of uncertain clinical significance (VUS). Using a tumor and matched germline targeted multi-gene panel approach, our classifier identifies all biallelic MUTYH carriers and all known non-carriers in an independent test set of 3019 colorectal cancers (accuracy = 100% (95% confidence interval 99.87-100%)). All monoallelic MUTYH carriers are classified with the non-MUTYH carriers. The classifier provides evidence for a pathogenic classification for two VUS and a benign classification for five VUS. Somatic hotspot mutations KRAS p.G12C and PIK3CA p.Q546K are associated with colorectal cancers from biallelic MUTYH carriers compared with non-carriers (p = 2 x 10(-23) and p = 6 x 10(-11), respectively). Here, we demonstrate the potential application of mutational signatures to tumor sequencing workflows to improve the identification of biallelic MUTYH carriers. Germline biallelic pathogenic MUTYH variants predispose patients to colorectal cancer (CRC); however, approaches to identify MUTYH variant carriers are lacking. Here, the authors evaluated mutational signatures that could distinguish MUTYH carriers in large CRC cohorts, and found MUTYH-associated somatic mutations

Efficacy of Chlorhexidine Varnish for the Prevention of Adult Caries: A Randomized Trial

The Prevention of Adult Caries Study, an NIDCR-funded multicenter, double-blind, randomized clinical trial, enrolled 983 adults (aged 18-80 yrs) at high risk for developing caries (20 or more intact teeth and 2 or more lesions at screening) to test the efficacy of a chlorhexidine diacetate 10% weight per volume (w/v) dental coating (CHX). We excluded participants for whom the study treatment was contraindicated or whose health might affect outcomes or ability to complete the study. Participants were randomly assigned to receive either the CHX coating (n = 490) or a placebo control (n = 493). Coatings were applied weekly for 4 weeks and a fifth time 6 months later. The primary outcome (total net D1-2FS increment) was the sum of weighted counts of changes in tooth surface status over 13 months. We observed no significant difference between the two treatment arms in either the intention-to-treat or per-protocol analyses. Analysis of 3 protocol-specified secondary outcomes produced similar findings. This trial failed to find that 10% (w/v) chlorhexidine diacetate coating was superior to placebo coating for the prevention of new caries (Clinicaltrials.gov registration number NCT00357877)

Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy.

We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities

Foraging Behaviours and Diets of Wolves in the Queen Maud Gulf Bird Sanctuary, Nunavut, Canada

Predation patterns often reflect the abundance and distribution of prey although factors such as vulnerability and ease of prey capture also affect these patterns. Wolves (Canis lupus) rely primarily on ungulates throughout most of their range even though other foods can be locally and seasonally important. We combined direct observation of wolves and scat analyses to examine the foraging behaviours and diets of wolves in the Queen Maud Gulf Bird Sanctuary, Nunavut, Canada. We were especially interested in how wolves used birds (primarily geese, Chen spp.) that were nesting in large numbers and dense colonies in the sanctuary. Caribou (Rangifer tarandus), which occurred in 65% of all scats, and bird prey, found in 29%, were the most common foods in scats, and behavioural observations confirmed this pattern. This study showed that caribou were the main prey of wolves in the Queen Maud Gulf Bird Sanctuary but that wolves also preyed on vulnerable and seasonally abundant foods, such as migratory birds, especially in late summer when ducks and geese were flightless during their annual remigial molt. © The Arctic Institute of North America

Crystallization and preliminary X-ray diffraction analysis of the complex of a human anti-ephrin type-A receptor 2 antibody fragment and its cognate antigen

Crystals of the complex between the Fab fragment of a human anti-EphA2 antibody and the N-terminal domain of human EphA2 have been obtained. Diffraction data were collected to 2.55 Å resolution