To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The Atlantic Sea Scallop fishery has grown tremendously over the past twenty years. The location and magnitude of harvestable biomass fluctuates dramatically due to both natural variation and the explicitly spatial management system designed to allow small individuals to grow larger and more valuable. These fluctuations in natural advantages can have profound effects on fishing ports. We use methods from economic growth literature to show that ports with lower initial scallop landings have grown the fastest. Furthermore, good access to biomass influences long-run changes in landings, although this effect exhibits considerable variability across ports. We also find evidence of returns to scope, suggesting that ports with other fishing activities could be well positioned to attract new scalloping activity when stock conditions are favorable. Further investigation of the largest ports using time-series methods also shows a high degree of variability; there are long-run relationships between scallop fishing and harvestable scallop stock in some ports, short-run relationships in some ports, and no relationship between the two in others. We interpret this as evidence that heterogeneity in the natural productivity of the ocean combined with explicitly spatial fisheries management has induced a spatial component to the port-level response to changes in biomass availability.
OBJECTIVES/SPECIFIC AIMS: Neurological injury remains as the main limiting factor for overall recovery after cardiac arrest (CA). Currently available indicators of neurological injury are inadequate for early prognostication after return of spontaneous circulation (ROSC). High diversification of brain mitochondrial cardiolipins (CL) makes them unique candidates to quantify brain injury and to predict prognosis early after ROSC. METHODS/STUDY POPULATION: CL content in plasma in 39 patients within 6 hours of ROSC and 10 healthy subjects as well as CL content in human heart and brain specimens were quantified using a high-resolution liquid chromatography mass spectrometry method. The quantities of brain-type CL species were correlated with clinical parameters of brain injury severity permitting derivation of a cerebral CL score (C-score) using linear regression. C-score and a single CL species (70:5) were evaluated in patients with varying neurological injury and outcome. Using a rat model of CA, CL was quantified in the plasma and brain of rats using similar methods and results compared with the controls. RESULTS/ANTICIPATED RESULTS: We found that brain and the heart fell on extreme ends of the CL diversity spectrum with 26 species of CL exclusively present in human brain not heart. Nine of these 26 species were present in plasma within 6 hours of ROSC with quantities correlating with greater brain injury. The C-score correlated with early neurologic injury and predicted discharge neurologic/functional outcome. CL (70:5) emerged as a potential point-of-care marker that alone was predictive of injury severity and outcome nearly as well as C-score. Using a rat CA model we showed a significant reduction in hippocampal CL content corresponding to CL released from the brain into systemic circulation. C-score was significantly increased in 10 minute Versus 5 minute no-flow CA and naïve controls. DISCUSSION/SIGNIFICANCE OF IMPACT: CA results in appearance and accumulation of CL in plasma, proportional to injury severity. Quantitation of brain-type CL species in plasma can be used to prognosticate neurological injury within 6 hours after ROSC.
Infectious mononucleosis is typically a self-limited viral infection of adolescence and early adulthood that resolves in a period of weeks, causing no major sequelae. We describe a case of a healthy 18-year-old female diagnosed with infectious mononucleosis who also presented with right upper quadrant abdominal pain, moderate transaminitis, and cholestatic biochemistry. An ultrasound revealed acute acalculous cholecystitis, generally a condition seen in the context of critical illness. Further investigating emergency department patients with infectious mononucleosis is often not indicated, but may be important for those who present atypically.
Pulsars in relativistic binary systems have emerged as fantastic natural laboratories for testing theories of gravity, the most prominent example being the double pulsar, PSR J0737–3039. The HTRU-South Low Latitude pulsar survey represents one of the most sensitive blind pulsar surveys taken of the southern Galactic plane to date, and its primary aim has been the discovery of new relativistic binary pulsars. Here we present our binary pulsar searching strategy and report on the survey’s flagship discovery, PSR J1757–1854. A 21.5-ms pulsar in a relativistic binary with an orbital period of 4.4 hours and an eccentricity of 0.61, this double neutron star (DNS) system is the most accelerated pulsar binary known, and probes a relativistic parameter space not yet explored by previous pulsar binaries.
Eating less frequently is associated with increased obesity risk in older children but data are potentially confounded by reverse causation, where bigger children eat less often in an effort to control their weight. Longitudinal data, particularly in younger children, are scarce. We aimed to determine whether eating frequency (meals and snacks) at 2 years of age is associated with past, current or subsequent BMI.
Cohort analysis of a randomised controlled trial. Eating frequency at 2 years of age was estimated using 48 h diaries that recorded when each child ate meals and snacks (parent-defined) in five-minute blocks. Body length/height and weight were measured at 1, 2 and 3·5 years of age. Linear regression assessed associations between the number of eating occasions and BMI Z-score, before and after adjustment for potential confounding variables.
Prevention of Overweight in Infancy (POI) study, Dunedin, New Zealand.
Children (n 371) aged 1–3·5 years.
On average, children ate 5·5 (sd 1·2) times/d at 2 years of age, with most children (88–89 %) eating 4–7 times/d. Eating frequency at 2 years was not associated with current (difference in BMI Z-score per additional eating occasion; 95 % CI: −0·02; −0·10, 0·05) or subsequent change (0·02; −0·03, 0·06) in BMI. Similarly, BMI at age 1 year did not predict eating frequency at 2 years of age (difference in eating frequency per additional BMI Z-score unit; 95 % CI: −0·03; −0·19, 0·13).
Number of eating occasions per day was not associated with BMI in young children in the present study.
We probe the relationship between surface magnetic fields and the X-ray emitting corona in the rapidly rotating star, AB Dor. Circularly polarised spectra have been inverted to produce a surface (photospheric) magnetic field map. This surface map has been extrapolated to model AB Dor's coronal field topology and X-ray light curve. Chandra/LETG light curves of AB Dor from the same epoch show intrinsic variability at the 30% level. Period analysis indicates a fraction of this is due to rotational modulation. We measure velocity shifts in emission line centroids as a function of Prot and find evidence of rotational modulation (max. vel. ∼ 40 ± 13km s—1). This modulation may indicate the presence of a localised X-ray emitting region at mid-to-high latitudes.
We present new results derived from high-resolution optical spectra of the τ Boo system, secured in March-May 2000. The results do not show the same feature reported by Cameron et al (1999) as a candidate reflected-light signature from the planet. Together with earlier results from the 1998 and 1999 seasons, the new data yield a 99.9% upper limit on the opposition planet/star flux ratio ∊ < 3.5 × 10−5 between 387.4 and 586.3 nm, a factor 3 deeper than the upper limit of Charbonneau et al (1999). For an assumed planet radius Rp = 1.2RJ, the upper limit on the mean geometric albedo is p < 0.22, 40% that of Jupiter. We find new evidence that the star's rotation is synchronised with the planet's orbital motion. Using a Monte Carlo analysis we infer that the planet's mass must lie in the range 5.5 to 10 times the mass of Jupiter.
Stellar coronae, like the interstellar medium, are multi-phase media. Physical conditions in different parts of the corona allow material to exist in thermal equilibrium either as a tenuous X-ray plasma at temperatures of several million degrees, or in a denser form at temperatures low enough for hydrogen to recombine.
I review recent progress in the field of stellar surface imaging, with particular reference to advanced methods for mapping surface-brightness distributions on magnetically active late-type stars. New signal enhancement techniques, utilising profile information from hundreds or thousands of photospheric lines simultaneously, allow images to be derived for stars several magnitudes fainter than was previously possible. For brighter stars, the same techniques make it possible to map features as small as two or three degrees in extent on the stellar surface. While this opens up whole new areas of research, such as the ability to use starspot tracking to study surface differential rotation patterns on single and binary stars, caution must be exercised in the treatment of “nuisance” parameters such as the stellar rotation rate, surface abundances and radial velocity. At the very high S:N levels we now use, the effects of systematic errors in these parameters are easier to identify, isolate and eliminate. This leads to the possibility of making precise radial velocity variations (at the few hundred m s−2 level or better) in late-type stars even with equatorial rotation speeds as high as 100 km s−1. This is particularly topical given the recent discovery that one of our prime imaging targets, the young southern K0 dwarf AB Doradus, has an astrometric companion in a highly eccentric orbit with an inferred mass close to the H-burning limit.
Doppler imaging has been used to image dark spots on the surfaces of rapidly rotating, magnetically active stars for the last 20 years. More recently, methods have been developed for combining line-profile information from large numbers of spectral lines simultaneously. This has allowed starspot distributions to be mapped in sufficient detail to allow tracking of individual spots over several stellar rotations, delineating surface differential rotation patterns for a number of stars. Zeeman-Doppler imaging allows the creation of stellar magnetograms, which are providing the first insights into the 3D topology of stellar coronal magnetic fields. The advent of cryogenic infrared echelle spectrographs opens up exciting new possibilities for Doppler imaging in molecular lines of species such as TiO, OH, and FeH.
Even in the new millenium, many astronomical objects cannot be resolved spatially with any available telescope. Most stars are too small and galaxies are too far away to be imaged directly or in detail in the foreseeable future. However, advances in data-analysis techniques allow us now to create detailed indirect images using tomographic methods. These images provide unprecedented insights into fundamental processes that drive the evolution of stars and galaxies, such as accretion and magnetic-field generation, on length scales that are of great physical importance but which are otherwise inaccessible.
Joint Discussion 09 was held on two half-days during the General Assembly. The main proceedings will be published in full in a special issue of Astronomische Nachrichten, to which the reader is referred, early in 2004. Here we give only a brief listing of subjects addressed and the titles of talks presented at the meeting.
The IAU Working Group on Extrasolar Planets (WGESP) was created by the Executive Council as a Working Group of Division III. This decision took place in June 1999, that is only 7 years after the discovery of planets around the pulsar PSR B1257+12 and 4 years after the discovery of 51 Peg b. This working group was renewed for 3 years at the General Assembly in 2003 in Sydney, Australia. It was chaired by Alan Boss from Carnegie Institution of Washington. The WGESP members were Paul Butler, William Hubbard, Philip Ianna, Martin Kürster, Jack Lissauer, Michel Mayor, Karen Meech, Francois Mignard, Alan Penny, Andreas Quirrenbach, Jill Tarter, and Alfred Vidal-Madjar.
In 2009, a metal-detector find of a rare garnet-inlaid composite disc brooch at West Hanney, Oxfordshire, led to the excavation of an apparently isolated female burial sited in a prominent position overlooking the Ock valley. The burial dates to the middle decades of the seventh century, a period of rapid socio-political development in the region, which formed the early heartland of the Anglo-Saxon kingdom of Wessex. The de luxe brooch links the wearer to two other burials furnished with very similar brooches at Milton, some 10km to the east and only c 1km from the Anglo-Saxon great hall complex at Sutton Courtenay / Drayton, just south of Abingdon. All three women must have been members of the region’s politically dominant group, known as the Gewisse. The burial’s grave goods and setting add a new dimension to our understanding of the richly furnished female burials that are such a prominent feature of the funerary record of seventh-century England.
Background: Recurrence of chronic subdural haematomas (CSDHs) after surgical drainage is a significant problem with rates up to 20%. This study focuses on determining factors predictive of haematoma recurrence and presents a scoring system stratifying recurrence risk for individual patients. Methods: Between the years 2005 and 2009, 331 consecutive patients with CSDHs treated with surgery were included in this study. Univariate and multivariate analyses were performed searching for risk factors of increased post-operative haematoma volume and haematoma recurrence requiring repeat drainage. Results: We found a 12% reoperation rate. CSDH septation (seen on computed tomogram scan) was found to be an independent risk factor for recurrence requiring reoperation (p=0.04). Larger post-operative subdural haematoma volume was also significantly associated with requiring a second drainage procedure (p<0.001). Independent risk factors of larger post-operative haematoma volume included septations within a CSDH (p<0.01), increased pre-operative haematoma volume (p<0.01), and a greater amount of parenchymal atrophy (p=0.04). A simple scoring system for quantifying recurrence risk was created and validated based on patient age (< or ≥80 years), haematoma volume (< or ≥160cc), and presence of septations within the subdural collection (yes or no). Conclusion: Septations within CSDHs are associated with larger post-operative residual haematoma collections requiring repeat drainage. When septations are clearly visible within a CSDH, craniotomy might be more suitable as a primary procedure as it allows greater access to a septated subdural collection. Our proposed scoring system combining haematoma volume, age, and presence of septations might be useful in identifying patients at higher risk for recurrence.