379 research outputs found
Strongholds of Ostrea edulis populations in estuaries in Essex, SE England and their association with traditional oyster aquaculture: evidence to support a MPA designation
The flat oyster Ostrea edulis has declined significantly in European waters since the 1850s as a result of anthropogenic activity. Ostrea edulis was designated a UK Biodiversity Action Plan Species and Habitat in 1995, and as a Feature of Conservation Importance (FOCI) within the UK Marine & Coastal Access Act 2009. To promote the recovery of oyster beds, a greater understanding of its abundance and distribution is required. Distribution of O. edulis across the proposed Blackwater, Crouch, Roach and Colne MCZ in Essex was determined between 2008 and 2012. Ostrea edulis were present in four estuary zones; with highest sample abundance in the Blackwater and Ray Sand zones. Size structure of populations varied, with the Ray Sand and Colne zones showing a significant lack of individuals with shell height <39 mm. Ostrea edulis occurred in highest number on shell substratum, followed by silty sediments. There were no significant associations between O. edulis abundance or size structure with water column Chl a, suspended solids, oxygen, nitrate or ammonium concentrations, temperature or pH. Highest abundance and most equitable population shell-size distribution for O. edulis were located within, or adjacent to, actively managed aquaculture zones. This suggests that traditional seabed management contributed to the maintenance or recovery of the species of conservation concern. Demonstration that the Essex estuaries were a stronghold for Ostrea edulis in the southern North sea area led to the designation of the Blackwater, Crouch, Roach and Colne estuaries Marine Conservation Zone in 2013
Searching for faces in crowd chokepoint videos
Investigations of face identification have typically focussed on matching faces to photographic IDs. Few researchers have considered the task of searching for a face in a crowd. In Experiment 1, we created the Chokepoint Search Test to simulate real‐time search for a target. Performance on this test was poor (39% accuracy) and showed moderate associations with tests of face matching and memory. In addition, trial‐level confidence predicted accuracy, and for those participants who were previously familiar with one or more targets, higher familiarity was associated with increased accuracy. In Experiment 2, we found improvements in performance on the test when three recent images of the target, but not three social media images, were displayed during searches. Taken together, our results highlight the difficulties inherent in real‐time searching for faces, with important implications for those security personnel who carry out this task on a daily basis
Transit and Eclipse Analyses of Exoplanet HD 149026b Using BLISS Mapping
The dayside of HD 149026b is near the edge of detectability by the Spitzer
Space Telescope. We report on eleven secondary-eclipse events at 3.6, 4.5, 3 x
5.8, 4 x 8.0, and 2 x 16 microns plus three primary-transit events at 8.0
microns. The eclipse depths from jointly-fit models at each wavelength are
0.040 +/- 0.003% at 3.6 microns, 0.034 +/- 0.006% at 4.5 microns, 0.044 +/-
0.010% at 5.8 microns, 0.052 +/- 0.006% at 8.0 microns, and 0.085 +/- 0.032% at
16 microns. Multiple observations at the longer wavelengths improved
eclipse-depth signal-to-noise ratios by up to a factor of two and improved
estimates of the planet-to-star radius ratio (Rp/Rs = 0.0518 +/- 0.0006). We
also identify no significant deviations from a circular orbit and, using this
model, report an improved period of 2.8758916 +/- 0.0000014 days.
Chemical-equilibrium models find no indication of a temperature inversion in
the dayside atmosphere of HD 149026b. Our best-fit model favors large amounts
of CO and CO2, moderate heat redistribution (f=0.5), and a strongly enhanced
metallicity. These analyses use BiLinearly-Interpolated Subpixel Sensitivity
(BLISS) mapping, a new technique to model two position-dependent systematics
(intrapixel variability and pixelation) by mapping the pixel surface at high
resolution. BLISS mapping outperforms previous methods in both speed and
goodness of fit. We also present an orthogonalization technique for
linearly-correlated parameters that accelerates the convergence of Markov
chains that employ the Metropolis random walk sampler. The electronic
supplement contains light-curve files and supplementary figures.Comment: Accepted for publication in Ap
Possible thermochemical disequilibrium in the atmosphere of the exoplanet GJ 436b
The nearby extrasolar planet GJ 436b--which has been labelled as a 'hot
Neptune'--reveals itself by the dimming of light as it crosses in front of and
behind its parent star as seen from Earth. Respectively known as the primary
transit and secondary eclipse, the former constrains the planet's radius and
mass, and the latter constrains the planet's temperature and, with measurements
at multiple wavelengths, its atmospheric composition. Previous work using
transmission spectroscopy failed to detect the 1.4-\mu m water vapour band,
leaving the planet's atmospheric composition poorly constrained. Here we report
the detection of planetary thermal emission from the dayside of GJ 436b at
multiple infrared wavelengths during the secondary eclipse. The best-fit
compositional models contain a high CO abundance and a substantial methane
(CH4) deficiency relative to thermochemical equilibrium models for the
predicted hydrogen-dominated atmosphere. Moreover, we report the presence of
some H2O and traces of CO2. Because CH4 is expected to be the dominant
carbon-bearing species, disequilibrium processes such as vertical mixing and
polymerization of methane into substances such as ethylene may be required to
explain the hot Neptune's small CH4-to-CO ratio, which is at least 10^5 times
smaller than predicted
Thermal Emission of WASP-14b Revealed with Three Spitzer Eclipses
Exoplanet WASP-14b is a highly irradiated, transiting hot Jupiter. Joshi et
al. calculate an equilibrium temperature Teq of 1866 K for zero albedo and
reemission from the entire planet, a mass of 7.3 +/- 0.5 Jupiter masses and a
radius of 1.28 +/- 0.08 Jupiter radii. Its mean density of 4.6 g/cm3 is one of
the highest known for planets with periods less than 3 days. We obtained three
secondary eclipse light curves with the Spitzer Space Telescope. The eclipse
depths from the best jointly fit model are +/- at 4.5
{\mu}m and +/- at 8.0 {\mu}m. The corresponding brightness
temperatures are 2212 +/- 94 K and 1590 +/- 116 K. A slight ambiguity between
systematic models suggests a conservative 3.6 {\mu}m eclipse depth of
+/- and brightness temperature of 2242 +/- 55 K. Although extremely
irradiated, WASP-14b does not show any distinct evidence of a thermal
inversion. In addition, the present data nominally favor models with day night
energy redistribution less than . The current data are generally
consistent with oxygen-rich as well as carbon-rich compositions, although an
oxygen-rich composition provides a marginally better fit. We confirm a
significant eccentricity of e = 0.087 +/- 0.002 and refine other orbital
parameters.Comment: 16 pages, 16 figure
Young people’s experiences of COVID-19 messaging at the start of the UK lockdown:Lessons for positive engagement and information sharing
BACKGROUND: To reduce COVID-19 infection rates during the initial stages of the pandemic, the UK Government mandated a strict period of restriction on freedom of movement or 'lockdown'. For young people, closure of schools and higher education institutions and social distancing rules may have been particularly challenging, coming at a critical time in their lives for social and emotional development. This study explored young people's experiences of the UK Government's initial response to the pandemic and related government messaging.METHODS: This qualitative study combines data from research groups at the University of Southampton, University of Edinburgh and University College London. Thirty-six online focus group discussions (FGDs) were conducted with 150 young people (Southampton: n = 69; FGD = 7; Edinburgh: n = 41; FGD = 5; UCL: n = 40; FGD = 24). Thematic analysis was conducted to explore how young people viewed the government's response and messaging and to develop recommendations for how to best involve young people in addressing similar crises in the future. RESULTS: The abrupt onset of lockdown left young people shocked, confused and feeling ignored by government and media messaging. Despite this, they were motivated to adhere to government advice by the hope that life might soon return to normal. They felt a responsibility to help with the pandemic response, and wanted to be productive with their time, but saw few opportunities to volunteer.CONCLUSIONS: Young people want to be listened to and feel they have a part to play in responding to a national crisis such as the COVID-19 epidemic. To reduce the likelihood of disenfranchising the next generation, Government and the media should focus on developing messaging that reflects young people's values and concerns and to provide opportunities for young people to become involved in responses to future crises
Tracking Parkinson's : Study Design and Baseline Patient Data
Peer reviewedPublisher PD
High C/O Chemistry and Weak Thermal Inversion in the Extremely Irradiated Atmosphere of Exoplanet WASP-12b
The carbon-to-oxygen ratio (C/O) in a planet provides critical information about its primordial origins and subsequent evolution. A primordial C/O greater than 0.8 causes a carbide-dominated interior as opposed to the silicate-dominated composition as found on Earth; the solar C/O is 0.54. Theory, shows that high C/O leads to a diversity of carbon-rich planets that can have very different interiors and atmospheres from those in the solar system. Here we report the detection of C/O greater than or equal to 1 in a planetary atmosphere. The transiting hot Jupiter WASP-12b has a dayside atmosphere depleted in water vapour and enhanced in methane by over two orders of magnitude compared to a solar-abundance chemical equilibrium model at the expected temperatures. The observed concentrations of the prominent molecules CO, CH4, and H2O are consistent with theoretical expectations for an atmosphere with the observed C/O = 1. The C/O ratios are not known for giant planets in the solar system, although they are expected to equal the solar value. If high C/O ratios are common, then extrasolar planets are likely very different in interior composition, and formed very differently, from expectations based on solar composition, potentially explaining the large diversity in observed radii. We also find that the extremely irradiated atmosphere (greater than 2500 K) of WASP-12b lacks a prominent thermal inversion, or a stratosphere, and has very efficient day-night energy circulation. The absence of a strong thermal inversion is in stark contrast to theoretical predictions for the most highly irradiated hot-Jupiter atmospheres
Peripheral hearing loss at age 70 predicts brain atrophy and associated cognitive change
BACKGROUND: Hearing loss has been proposed as a modifiable risk factor for dementia. However, the relationship between hearing, neurodegeneration, and cognitive change, and the extent to which pathological processes such as Alzheimer's disease and cerebrovascular disease influence these relationships, is unclear. METHODS: Data from 287 adults born in the same week of 1946 who underwent baseline pure tone audiometry (mean age=70.6 years) and two time point cognitive assessment/multimodal brain imaging (mean interval 2.4 years) were analysed. Hearing impairment at baseline was defined as a pure tone average of greater than 25 decibels in the best hearing ear. Rates of change for whole brain, hippocampal and ventricle volume were estimated from structural MRI using the Boundary Shift Integral. Cognition was assessed using the Pre-clinical Alzheimer's Cognitive Composite. Regression models were performed to evaluate how baseline hearing impairment associated with subsequent brain atrophy and cognitive decline after adjustment for a range of confounders including baseline β-amyloid deposition and white matter hyperintensity volume. RESULTS: 111 out of 287 participants had hearing impairment. Compared with those with preserved hearing, hearing impaired individuals had faster rates of whole brain atrophy, and worse hearing (higher pure tone average) predicted faster rates of hippocampal atrophy. In participants with hearing impairment, faster rates of whole brain atrophy predicted greater cognitive change. All observed relationships were independent of β-amyloid deposition and white matter hyperintensity volume. CONCLUSIONS: Hearing loss may influence dementia risk via pathways distinct from those typically implicated in Alzheimer's and cerebrovascular disease in cognitively unimpaired older adults
Investigating the relationship between BMI across adulthood and late life brain pathologies.
BACKGROUND: In view of reported associations between high adiposity, particularly in midlife and late-life dementia risk, we aimed to determine associations between body mass index (BMI), and BMI changes across adulthood and brain structure and pathology at age 69-71 years. METHODS: Four hundred sixty-five dementia-free participants from Insight 46, a sub-study of the British 1946 birth cohort, who had cross-sectional T1/FLAIR volumetric MRI, and florbetapir amyloid-PET imaging at age 69-71 years, were included in analyses. We quantified white matter hyperintensity volume (WMHV) using T1 and FLAIR 3D-MRI; β-amyloid (Aβ) positivity/negativity using a SUVR approach; and whole brain (WBV) and hippocampal volumes (HV) using 3D T1-MRI. We investigated the influence of BMI, and BMI changes at and between 36, 43, 53, 60-64, 69 and 71 years, on late-life WMHV, Aβ-status, WBV and mean HV. Analyses were repeated using overweight and obese status. RESULTS: At no time-point was BMI, change in BMI or overweight/obese status associated with WMHV or WBV at age 69-71 years. Decreasing BMI in the 1-2 years before imaging was associated with an increased odds of being β-amyloid positive (OR 1.45, 95% confidence interval 1.09, 1.92). There were associations between being overweight and larger mean HV at ages 60-64 (β = 0.073 ml, 95% CI 0.009, 0.137), 69 (β = 0.076 ml, 95% CI 0.012, 0.140) and 71 years (β = 0.101 ml, 95% CI 0.037, 0.165). A similar, albeit weaker, trend was seen with obese status. CONCLUSIONS: Using WMHV, β-amyloid status and brain volumes as indicators of brain health, we do not find evidence to explain reported associations between midlife obesity and late-life dementia risk. Declining BMI in later life may reflect preclinical Alzheimer's disease
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