Comparison of the HadGEM2 climate-chemistry model against in situ and SCIAMACHY atmospheric methane data

Wetlands are a major emission source of methane (CH4) globally. In this study, we evaluate wetland emission estimates derived using the UK community land surface model (JULES, the Joint UK Land Earth Simulator) against atmospheric observations of methane, including, for the first time, total methane columns derived from the SCIAMACHY instrument on board the ENVISAT satellite. Two JULES wetland emission estimates are investigated: (a) from an offline run driven with Climatic Research Unit–National Centers for Environmental Prediction (CRU-NCEP) meteorological data and (b) from the same offline run in which the modelled wetland fractions are replaced with those derived from the Global Inundation Extent from Multi-Satellites (GIEMS) remote sensing product. The mean annual emission assumed for each inventory (181 Tg CH4 per annum over the period 1999–2007) is in line with other recently published estimates. There are regional differences as the unconstrained JULES inventory gives significantly higher emissions in the Amazon (by ~36 Tg CH4 yr−1) and lower emissions in other regions (by up to 10 Tg CH4 yr−1) compared to the JULES estimates constrained with the GIEMS product. Using the UK Hadley Centre's Earth System model with atmospheric chemistry (HadGEM2), we evaluate these JULES wetland emissions against atmospheric observations of methane. We obtain improved agreement with the surface concentration measurements, especially at high northern latitudes, compared to previous HadGEM2 runs using the wetland emission data set of Fung et al. (1991). Although the modelled monthly atmospheric methane columns reproduce the large-scale patterns in the SCIAMACHY observations, they are biased low by 50 part per billion by volume (ppb). Replacing the HadGEM2 modelled concentrations above 300 hPa with HALOE–ACE assimilated TOMCAT output results in a significantly better agreement with the SCIAMACHY observations. The use of the GIEMS product to constrain the JULES-derived wetland fraction improves the representation of the wetland emissions in JULES and gives a good description of the seasonality observed at surface sites influenced by wetlands, especially at high latitudes. We find that the annual cycles observed in the SCIAMACHY measurements and at many of the surface sites influenced by non-wetland sources cannot be reproduced in these HadGEM2 runs. This suggests that the emissions over certain regions (e.g. India and China) are possibly too high and/or the monthly emission patterns for specific sectors are incorrect. The comparisons presented in this paper show that the performance of the JULES wetland scheme is comparable to that of other process-based land surface models. We identify areas for improvement in this and the atmospheric chemistry components of the HadGEM Earth System model. The Earth Observation data sets used here will be of continued value in future evaluations of JULES and the HadGEM family of models

On gravitational waves emitted by an ensemble of rotating neutron stars

We study the possibility to detect the gravitational wave background generated by all the neutron stars in the Galaxy with only one gravitational wave interferometric detector. The proposed strategy consists in squaring the detector's output and searching for a sidereal modulation. The shape of the squared signal is computed for a disk and a halo distribution of neutron stars. The required noise stability of the interferometric detector is discussed. We argue that a possible population of old neutron stars, originating from a high stellar formation rate at the birth of the Galaxy and not emitting as radio pulsars, could be detected by the proposed technique in the low frequency range of interferometric experiments.Comment: 14 pages, 2 PostScript figures, RevTeX, accepted for publication in Physical Review

Genome-wide association study in frontal fibrosing alopecia identifies four susceptibility loci including HLA-B*07:02

Frontal fibrosing alopecia (FFA) is a recently described inflammatory and scarring type of hair loss affecting almost exclusively women. Despite a dramatic recent increase in incidence the aetiopathogenesis of FFA remains unknown. We undertake genome-wide association studies in females from a UK cohort, comprising 844 cases and 3,760 controls, a Spanish cohort of 172 cases and 385 controls, and perform statistical meta-analysis. We observe genome-wide significant association with FFA at four genomic loci: 2p22.2, 6p21.1, 8q24.22 and 15q2.1. Within the 6p21.1 locus, fine-mapping indicates that the association is driven by the HLA-B*07:02 allele. At 2p22.1, we implicate a putative causal missense variant in CYP1B1, encoding the homonymous xenobiotic- and hormone-processing enzyme. Transcriptomic analysis of affected scalp tissue highlights overrepresentation of transcripts encoding components of innate and adaptive immune response pathways. These findings provide insight into disease pathogenesis and characterise FFA as a genetically predisposed immuno-inflammatory disorder driven by HLA-B*07:02

Focal metatarsal fistulae syndrome affecting a greyhound dog successfully treated with topical 0.1% tacrolimus ointment

Metatarsal fistulation is an uncommon cutaneous condition reported almost exclusively in German shepherd dogs and their cross-breeds. To the best of the authors' knowledge this is the first reported case of focal metatarsal fistulae syndrome affecting a greyhound. Remission was obtained within 6 weeks of commencing treatment using compounded 0.1% tacrolimus ointment twice daily and the dog remained stable for another 6 months with twice weekly application before treatment was discontinued. The dog remained in remission at the time of writing, which is 1 year after treatment withdrawal

First report of angio-oedema subsequent to the administration of allergen specific sublingual immunotherapy for the management of equine hypersensitivity dermatitis

Background: Sublingual immunotherapy (SLIT) offers an alternative mode of allergen delivery to subcutaneous immunotherapy (SCIT) with the aim of inducing immunological tolerance. Currently, there are no published reports regarding the efficacy or safety of SLIT in horses. Hypothesis/Objective: To describe the first case of several adverse events occurring in a horse subsequent to the repeat administration of SLIT. Animal: A seven-year-old, warmblood mare with a confirmed diagnosis of equine hypersensitivity dermatitis (EHD). Methods and results: Immunotherapy was recommended for management of EHD. Due to the temperament of the horse, the owner elected to proceed with SLIT. Thirty six hours after commencing SLIT, the mare developed scleral oedema, moderate dyspnoea and abdominal discomfort. SLIT was withdrawn for 10 days and re instituted using a ten-fold dilution of the original vaccine. Localized oedema and swelling of the tongue developed within 12 h of administration. At this juncture, SLIT was withdrawn. The horse was rechallenged with the SLIT allergen vehicle, 50% glycerine and no adverse reactions occurred. SCIT was commenced using the same allergens and no adverse events occurred with repeated administration. Conclusions and clinical importance: To the best of the authors' knowledge, this is the first reported case of adverse reactions developing subsequent to the administration of SLIT for the management of EHD

Determination of threshold concentrations of plant pollens in intradermal testing using fluorescein in clinically healthy nonallergic cats

Background: Currently the same allergen concentrations for canine intradermal testing (IDT) are recommended for feline IDT. Feline skin reactions are subtle and more difficult to read than canine reactions. This difference may be due to suboptimal allergen concentrations used for IDT in cats. Hypothesis/Objectives: To determine the irritant threshold concentration (ITC) of 16 pollen allergens using serial dilutions of allergen and intravenous fluorescein. The hypothesis tested was that feline IDT currently is performed at suboptimal allergen concentrations for pollens. Animals: Twenty privately owned healthy clinically nonallergic cats. Methods: IDT was performed in duplicate using 16 pollen allergens (weeds, grasses and trees) at a dilution of 8000 PNU/mL. Two blinded investigators graded the test reactions independently using subjective and objective criteria. Intravenous fluorescein was then administered and the test reactions were re-evaluated. IDT was repeated for any allergen that was positive, using serial dilutions of allergen at a concentration of 6000 and 4000 PNU/mL. Results: The ITC for 2 of 16 of the allergens was determined. The ITC of Cynodon dactylon (Bermuda grass) and Schinus spp. (Peppercorn) was determined to be between 6000 and 8000 PNU/mL. The ITC of all other allergens tested in this study was >8000 PNU/mL. Conclusions and clinical importance: This study confirms that suboptimal allergen concentrations currently are used for feline IDT as the ITC is >8000 PNU/mL for 14 of 16 of the grass, weed and tree pollens evaluated. The ITC of Cynodon dactylon and Schinus spp. was determined to be between 6000 and 8000 PNU/m