987 research outputs found
Winter residency and site association in the critically endangered North East Atlantic spurdog (Squalus acanthias)
Identification and incorporation of residential behaviour into elasmobranch management plans has the potential to substantially increase their effectiveness by identifying sites where Marine Protected Areas (MPAs) might be used to help conserve species with high migratory potential. There is evidence that spurdog (Squalus acanthias) displays site association in some parts of its global distribution, but this has currently not been shown within the North East Atlantic where it is critically endangered. Here we investigate the movements of electronically tagged spurdog within Loch Etive, a sea loch on the west coast of Scotland. Archival data storage tags (DSTs), that recorded depth and temperature, revealed that mature female spurdog over wintered within the loch, restricting their movements to the upper basin, and remaining either in the loch or the local vicinity for the rest of the year. This finding was supported by evidence for limited movements from conventional mark/recapture data and acoustically tagged individual spurdog. Some of the movements between the loch basins appear to be associated with breeding and parturition events. This high level of site association suggests that spatial protection of the loch would aid the conservation of different age and sex classes of spurdog
Utility of ElastPQ point-shear wave elastography in the work-up of patients with primary sclerosing cholangitis
Background & Aims: Liver stiffness measurement (LSM) and spleen stiffness measurement (SSM) have been shown to be useful tools for assessing the risk of fibrosis and portal hypertension, respectively. However, data on the accuracy of LSM and SSM measured by point-shear wave elastography (pSWE) in patients affected by primary sclerosing cholangitis (PSC) are still lacking. Thus, we aimed to prospectively assess their performance in a cohort of patients with PSC. Methods: We determined the correlation between LSM assessed by a pSWE technique (ElastPQ) and by FibroScan-transient elastography (F-TE). Furthermore, we used receiver-operating characteristic curves and area under the curves (AUROC) to evaluate the performance of LSM by ElastPQ for the staging of fibrosis, using F-TE as a reference standard, and the performance of LSM and SSM by ElastPQ in predicting the presence of oesophageal varices (OVs). Results: One hundred and fifty-two patients with PSC (93 males [61.2%], mean age 46 ± 16 years) were prospectively recruited. ElastPQ and F-TE LSMs were available for all patients, while ElastPQ SSM was available in 109 (72%) patients of whom 35 underwent upper gastrointestinal endoscopy within 1 year of the ultrasound assessment. ElastPQ LSM showed an excellent correlation with F-TE (p <0.001, Spearman's 0.93; Lin's 0.86) and a good diagnostic accuracy for fibrosis staging along all stages of liver fibrosis (AUROCs 0.96, 0.97, 0.97 and 0.99 for fibrosis stages F≥1, F≥2, F≥3 and F=4, respectively), using F-TE as a surrogate of histological fibrosis. ElastPQ SSM showed a good diagnostic performance in predicting the presence of OVs at endoscopy. Conclusions: LSM and SSM by ElastPQ can be used as accurate tools for liver fibrosis risk assessment and fibrosis staging, as well as for predicting the presence of OVs in the work-up of patients with PSC. Impact and implications: Liver and spleen stiffness measurement (LSM and SSM, respectively) by ElastPQ point-shear wave elastography in patients with primary sclerosing cholangitis represent reliable and reproducible tools for non-invasively staging the severity of liver disease and stratifying patients according to their risk of developing liver-related outcomes. In particular, LSM shows good accuracy for staging liver fibrosis and therefore detecting those patients at high risk of having compensated advanced chronic liver disease who require close monitoring. SSM seems to be promising to detect the risk of portal hypertension and therefore of oesophageal varices, enabling the triaging of patients who really need to undergo a screening endoscopy
Chalk cliff retreat in East Sussex and Kent 1870s to 2001
The retreat of chalk cliffs fringing the eastern English Channel contributes shingle to the beaches which helps to protect the cliffs and slow down erosion. Conversely, cliff retreat endangers settlements and infrastructure on the clifftop. Rates of retreat have been calculated by a variety of methods over the past century, but no attempt has been made to provide a complete coverage that allows for a true comparison of retreat rates over the entire coastline. Using historic maps and recent orthophotos, cliff retreat rates have been calculated for consecutive 50 m sections of chalk cliff along the English side of the entire eastern English Channel for a period of 125 years. The chalk cliffs of East Sussex erode at an average rate of 0.25 - 0.3 m y−1 while those in Kent at a rate of 0.1 m y−1
Detailed Analysis of Nearby Bulgelike Dwarf Stars II. Lithium Abundances
Li abundances are derived for a sample of bulgelike stars with isochronal
ages of 10-11 Gyr. These stars have orbits with pericentric distances, Rp, as
small as 2-3 kpc and Zmax < 1 kpc. The sample comprises G and K dwarf stars in
the metallicity range -0.80<[Fe/H]< +0.40. Few data of Li abundances in old
turn-off stars (> 4.5 Gyr) within the present metallicity range are available.
M67 (4.7 Gyr) and NGC 188 (6 Gyr) are the oldest studied metal-rich open
clusters with late-type stars. Li abundances have also been studied for few
samples of old metal-rich field stars. In the present work a high dispersion in
Li abundances is found for bulgelike stars for all the metallicity range,
comparable with values in M67. The role of metallicity and age on a Li
depletion pattern is discussed. The possible connection between Li depletion
and oxygen abundance due to atmospheric opacity effects is investigated.Comment: 9 pages, 7 figure
Identification of HCCC as a diffuse interstellar band carrier
We present strong evidence that the broad, diffuse interstellar bands (DIBs)
at 4881 and 5450\,\AA are caused by the
B\,^1B\,\,X\,^1A transition of HCCC (l-CH).
The large widths of the bands are due to the short lifetime of the B\,^1B
electronic state. The bands are predicted from absorption measurements in a
neon matrix and observed by cavity ring-down in the gas phase and show exact
matches to the profiles and wavelengths of the two broad DIBs. The strength of
the 5450\,\AA DIB leads to a l-CH column density of
cm towards HD\,183143 and
\,cm to HD\,206267. Despite similar values of
(), the 4881 and 5450\,\AA DIBs in HD\,204827 are less than one third
their strength in HD\,183143, while the column density of interstellar C is
unusually high for HD\,204827 but undetectable for HD\,183143. This can be
understood if C has been depleted by hydrogenation to species such as
l-CH towards HD\,183143. There are also three rotationally resolved
sets of triplets of l-CH in the 61506330\,\AA region. Simulations,
based on the derived spectroscopic constants and convolved with the expected
instrumental and interstellar line broadening, show credible coincidences with
sharp, weak DIBs for the two observable sets of triplets. The region of the
third set is too obscured by the -band of telluric O.Comment: 22 pages, 9 figure
The Los Alamos Trapped Ion Quantum Computer Experiment
The development and theory of an experiment to investigate quantum
computation with trapped calcium ions is described. The ion trap, laser and ion
requirements are determined, and the parameters required for quantum logic
operations as well as simple quantum factoring are described.Comment: 41 pages, 16 figures, submitted to Fortschritte der Physi
Centrosymmetric molecules as possible carriers of diffuse interstellar bands
In this paper, we present new data with interstellar C2 (Phillips bands A-X),
from observations made with the Ultraviolet-Visual Echelle Spectrograph of the
European Southern Observatory. We have determined the interstellar column
densities and excitation temperatures of C2 for nine Galactic lines. For seven
of these, C2 has never been observed before, so in this case the still small
sample of interstellar clouds (26 lines of sight), where a detailed analysis of
C2 excitation has been made, has increased significantly. This paper is a
continuation of previous works where interstellar molecules (C2 and diffuse
interstellar bands) have been analysed. Because the sample of interstellar
clouds with C2 has increased, we can show that the width and shape of the
profiles of some diffuse interstellar bands (6196 and 5797 A) apparently depend
on the gas kinetic and rotational temperatures of C2; the profiles are broader
because of the higher values of the gas kinetic and rotational temperatures of
C2. There are also diffuse interstellar bands (4964 and 5850 A) for which this
effect does not exist.Comment: 8 pages, 4 figures, accepted to MNRAS 201
Collagen proportionate area correlates with histological stage and predicts clinical events in primary sclerosing cholangitis
Background & Aims:
Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease in need of accurate biomarkers for stratification and as surrogates for clinical endpoints in trials. Quantitative liver fibrosis assessment by collagen proportionate area (CPA) measurement has been demonstrated to correlate with clinical outcomes in chronic hepatitis C, alcohol-related and non-alcoholic fatty liver disease. We aimed to investigate the ability of CPA to quantify liver fibrosis and predict clinical events in PSC.
Methods:
Biopsies from 101 PSC patients from two European centres were retrospectively assessed by two expert pathologists in tandem, using grading (Ishak and Nakanuma) and staging (Ishak, Nakanuma, Ludwig) systems recently validated to predict clinical events in PSC. CPA was determined by image analysis of picro-Sirius red-stained sections following a standard protocol. We assessed the correlations between CPA, staging and grading and their associations with three outcomes: (1) time to PSC-related death, liver transplant or primary liver cancer; (2) liver transplant-free survival; (3) occurrence of cirrhosis-related clinical manifestations.
Results:
CPA correlated strongly with histological stage determined by each scoring system (P < .001) and was significantly associated with the three endpoints. Median time to endpoint-1, endpoint-2 and endpoint-3 was shorter in patients with higher CPA, on Kaplan-Meier analyses (P = .011, P = .034 and P = .001, respectively).
Conclusion:
Quantitative fibrosis assessment by CPA has utility in PSC. It correlates with established histological staging systems and predicts clinical events. CPA may be a useful tool for staging fibrosis and for risk stratification in PSC and should be evaluated further within prospective clinical trials
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