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Regional and monthly and clear-sky aerosol direct radiative effect (and forcing) derived from the GlobAEROSOL-AATSR satellite aerosol product
Using the GlobAEROSOL-AATSR dataset, estimates
of the instantaneous, clear-sky, direct aerosol radiative
effect and radiative forcing have been produced for the year
2006. Aerosol Robotic Network sun-photometer measurements
have been used to characterise the random and systematic
error in the GlobAEROSOL product for 22 regions covering
the globe. Representative aerosol properties for each
region were derived from the results of a wide range of literature sources and, along with the de-biased GlobAEROSOL
AODs, were used to drive an offline version of the Met Office unified model radiation scheme. In addition to the mean AOD, best-estimate run of the radiation scheme, a range of additional calculations were done to propagate uncertainty estimates in the AOD, optical properties, surface albedo and errors due to the temporal and spatial averaging of the AOD fields. This analysis produced monthly, regional estimates of the clear-sky aerosol radiative effect and its uncertainty, which were combined to produce annual, global mean values of (−6.7±3.9)Wm−2 at the top of atmosphere (TOA) and (−12±6)Wm−2 at the surface. These results were then used to give estimates of regional, clear-sky aerosol direct radiative forcing, using modelled pre-industrial AOD fields for the year 1750 calculated for the AEROCOM PRE experiment. However, as it was not possible to quantify the uncertainty in the pre-industrial aerosol loading, these figures can only be taken as indicative and their uncertainties as lower bounds on the likely errors. Although the uncertainty on aerosol radiative effect presented here is considerably larger than most previous estimates, the explicit inclusion of the major sources of error in the calculations suggest that they are closer to the true constraint on this figure from similar methodologies, and point to the need for more, improved estimates of both global aerosol loading and aerosol optical properties
Intercomparison of Metop-A SO2 measurements during the 2010- 2011 Icelandic eruptions
The European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Aviation
Hazards, was introduced after the eruption of the Icelandic volcano Eyjafjallajökull in the spring of 2010
to facilitate the development of an optimal EndtoEnd
System for Volcanic Ash Plume Monitoring and Prediction.
The Eyjafjallajökull plume drifted towards Europe and caused major disruptions of European air traffic for
several weeks affecting the everyday life of millions of people. The limitations in volcanic plume monitoring and
prediction capabilities gave birth to this observational system which is based on comprehensive satellitederived
ash plume and sulphur dioxide [SO2] level estimates, as well as a widespread validation using supplementary
satellite, aircraft and groundbased
measurements. Intercomparison
of the volcanic total SO2 column and
plume height observed by GOME2/
MetopA
and IASI/MetopA
are shown before, during and after the Eyjafjallajökull
2010 eruptions as well as for the 2011 GrÃmsvötn eruption. Colocated
groundbased
Brewer Spectrophotometer
data extracted from the World Ozone and Ultraviolet Radiation Data Centre for de Bilt, the Netherlands,
are also compared to the different satellite estimates. Promising agreement is found for the two different
types of instrument for the SO2 columns with linear regression coefficients ranging around from 0.64 when
comparing the different instruments and 0.85 when comparing the two different IASI algorithms. The agreement
for the plume height is lower, possibly due to the major differences between the height retrieval part of the
GOME2 and IASI algorithms. The comparisons with the Brewer groundbased
station in de Bilt, The Netherlands
show good qualitative agreement for the peak of the event however stronger eruptive signals are required
for a longer quantitative comparison
The quorum sensing transcription factor AphA directly regulates natural competence in Vibrio cholerae
Many bacteria use population density to control gene expression via quorum sensing. In Vibrio cholerae, quorum sensing coordinates virulence, biofilm formation, and DNA uptake by natural competence. The transcription factors AphA and HapR, expressed at low and high cell density respectively, play a key role. In particular, AphA triggers the entire virulence cascade upon host colonisation. In this work we have mapped genome-wide DNA binding by AphA. We show that AphA is versatile, exhibiting distinct modes of DNA binding and promoter regulation. Unexpectedly, whilst HapR is known to induce natural competence, we demonstrate that AphA also intervenes. Most notably, AphA is a direct repressor of tfoX, the master activator of competence. Hence, production of AphA markedly suppressed DNA uptake; an effect largely circumvented by ectopic expression of tfoX. Our observations suggest dual regulation of competence. At low cell density AphA is a master repressor whilst HapR activates the process at high cell density. Thus, we provide deep mechanistic insight into the role of AphA and highlight how V. cholerae utilises this regulator for diverse purposes
Lead Bullet Fragments in Venison from Rifle-Killed Deer: Potential for Human Dietary Exposure
Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15–409) and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80%) of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 µg/dL (maximum 3.8 µg/dL) 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 µg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low-income beneficiaries of venison donations
Masked suffix priming and morpheme positional constraints
Although masked stem priming (e.g., dealer\u2013DEAL) is one of the most established effects in visual word identification (e.g., Grainger et al., 1991), it is less clear whether primes and targets sharing a suffix (e.g., kindness\u2013WILDNESS) also yield facilitation (Giraudo & Grainger, 2003; Du\uf1abeitia et al., 2008). In a new take on this issue, we show that prime nonwords facilitate lexical decisions to target words ending with the same suffix (sheeter\uac\u2013TEACHER) compared to a condition where the critical suffix was substituted by another one (sheetal\u2013TEACHER) or by an unrelated non\u2013morphological ending (sheetub\u2013 TEACHER). We also show that this effect is genuinely morphological, as no priming emerged in non\u2013complex items with the same orthographic characteristics (sportel\u2013BROTHEL vs. sportic\u2013BROTHEL vs. sportur\u2013BROTHEL). In a further experiment, we took advantage of these results to assess whether suffixes are recognized in a position\u2013specific fashion. Masked suffix priming did not emerge when the relative order of stems and suffixes was reversed in the prime nonwords\u2014ersheet did not yield any time saving in the identification of teacher as compared to either alsheet or obsheet. We take these results to show that \u2013er was not identified as a morpheme in ersheet, thus indicating that suffix identification is position specific. This conclusion is in line with data on interference effects in nonword rejection (Crepaldi, Rastle, & Davis, 2010), and strongly constrains theoretical proposals on how complex words are identified. In particular, because these findings were reported in a masked priming paradigm, they suggest that positional constraints operate early, most likely at a pre\u2013lexical level of morpho\u2013orthographic analysi
Omicron variant infection in inflammatory rheumatological conditions – outcomes from a COVID-19 naive population in Aotearoa New Zealand
Background: Due to geographic isolation and border controls Aotearoa New Zealand (AoNZ) attained high levels of population coronavirus disease-19 (COVID-19) vaccination before widespread transmission of COVID-19. We describe outcomes of SARS-CoV-2 infection (Omicron variant) in people with inflammatory rheumatic diseases in this unique setting. Methods: This observational study included people with inflammatory rheumatic disease and SARS-CoV-2 infection in AoNZ between 1 February and 30 April 2022. Data were collected via the Global Rheumatology Alliance Registry including demographic and rheumatic disease characteristics, and COVID-19 vaccination status and outcomes. Multivariable logistic regression was used to explore associations of demographic and clinical factors with COVID-19 hospitalisation and death. Findings: Of the 1599 cases included, 96% were from three hospitals that systematically identified people with inflammatory rheumatic disease and COVID-19. At time of COVID-19, 1513 cases (94.6%) had received at least two COVID-19 vaccinations. Hospitalisation occurred for 104 (6.5%) cases and 10 (0.6%) patients died. Lower frequency of hospitalisation was seen in cases who had received at least two vaccinations (5.9%), compared to the unvaccinated (20.6%) or those with a single vaccine dose (10.7%). In multivariable adjusted models, people with gout or connective tissue diseases (CTD) had increased risk of the combined outcome of hospitalisation/death, compared to people with inflammatory arthritis. Glucocorticoid and rituximab use were associated with increased rates of hospitalisation/death. All patients who died had three or more co-morbidities or were over 60 years old. Interpretation: In this cohort with inflammatory rheumatic diseases and high vaccination rates, severe outcomes from SARS-CoV-2 Omicron variant were relatively infrequent. The outcome of Omicron variant infection among vaccinated but SARS-CoV-2 infection-naive people with inflammatory rheumatic disease without other known risk factors were favourable. Funding: Financial support from the American College of Rheumatology (ACR) and European Alliance of Associations for Rheumatology (EULAR) included management of COVID-19 Global Rheumatology Alliance funds
An Input-to-State Stability Approach to Verify Almost Global Stability of a Synchronous-Machine-Infinite-Bus System
Conditions for almost global stability of an operating point of a realistic model of a synchronous generator with constant field current connected to an infinite bus are derived. The analysis is conducted by employing the recently proposed concept of input-to-state stability (ISS)–Leonov functions, which is an extension of the powerful cell structure principle developed by Leonov and Noldus to the ISS framework. Compared with the original ideas of Leonov and Noldus, the ISS–Leonov approach has the advantage of providing additional robustness guarantees. The efficiency of the derived sufficient conditions is illustrated via numerical experiments
Ultra High Energy Cosmology with POLARBEAR
Observations of the temperature anisotropy of the Cosmic Microwave Background
(CMB) lend support to an inflationary origin of the universe, yet no direct
evidence verifying inflation exists. Many current experiments are focussing on
the CMB's polarization anisotropy, specifically its curl component (called
"B-mode" polarization), which remains undetected. The inflationary paradigm
predicts the existence of a primordial gravitational wave background that
imprints a unique B-mode signature on the CMB's polarization at large angular
scales. The CMB B-mode signal also encodes gravitational lensing information at
smaller angular scales, bearing the imprint of cosmological large scale
structures (LSS) which in turn may elucidate the properties of cosmological
neutrinos. The quest for detection of these signals; each of which is orders of
magnitude smaller than the CMB temperature anisotropy signal, has motivated the
development of background-limited detectors with precise control of systematic
effects. The POLARBEAR experiment is designed to perform a deep search for the
signature of gravitational waves from inflation and to characterize lensing of
the CMB by LSS. POLARBEAR is a 3.5 meter ground-based telescope with 3.8
arcminute angular resolution at 150 GHz. At the heart of the POLARBEAR receiver
is an array featuring 1274 antenna-coupled superconducting transition edge
sensor (TES) bolometers cooled to 0.25 Kelvin. POLARBEAR is designed to reach a
tensor-to-scalar ratio of 0.025 after two years of observation -- more than an
order of magnitude improvement over the current best results, which would test
physics at energies near the GUT scale. POLARBEAR had an engineering run in the
Inyo Mountains of Eastern California in 2010 and will begin observations in the
Atacama Desert in Chile in 2011.Comment: 8 pages, 6 figures, DPF 2011 conference proceeding
The bolometric focal plane array of the Polarbear CMB experiment
The Polarbear Cosmic Microwave Background (CMB) polarization experiment is
currently observing from the Atacama Desert in Northern Chile. It will
characterize the expected B-mode polarization due to gravitational lensing of
the CMB, and search for the possible B-mode signature of inflationary
gravitational waves. Its 250 mK focal plane detector array consists of 1,274
polarization-sensitive antenna-coupled bolometers, each with an associated
lithographed band-defining filter. Each detector's planar antenna structure is
coupled to the telescope's optical system through a contacting dielectric
lenslet, an architecture unique in current CMB experiments. We present the
initial characterization of this focal plane
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