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 email@example.com
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.
We present the first data release of the SkyMapper Southern Survey, a hemispheric survey carried out with the SkyMapper Telescope at Siding Spring Observatory in Australia. Here, we present the survey strategy, data processing, catalogue construction, and database schema. The first data release dataset includes over 66 000 images from the Shallow Survey component, covering an area of 17 200 deg2 in all six SkyMapper passbands uvgriz, while the full area covered by any passband exceeds 20 000 deg2. The catalogues contain over 285 million unique astrophysical objects, complete to roughly 18 mag in all bands. We compare our griz point-source photometry with Pan-STARRS1 first data release and note an RMS scatter of 2%. The internal reproducibility of SkyMapper photometry is on the order of 1%. Astrometric precision is better than 0.2 arcsec based on comparison with Gaia first data release. We describe the end-user database, through which data are presented to the world community, and provide some illustrative science queries.
Radar observations are a powerful technique to study near-Earth asteroids (NEAs). Goldstone's 3.75 m resolution capability is invaluable when attempting to image NEAs with diameters smaller than 140 m. The small NEAs are a very diverse population in which we continue to discover unusual objects.
The Australian Imaging, Biomarkers and Lifestyle (AIBL) Flagship Study of Ageing is a prospective study of 1,112 individuals (211 with Alzheimer's disease (AD), 133 with mild cognitive impairment (MCI), and 768 healthy controls (HCs)). Here we report diagnostic and cognitive findings at the first (18-month) follow-up of the cohort. The first aim was to compute rates of transition from HC to MCI, and MCI to AD. The second aim was to characterize the cognitive profiles of individuals who transitioned to a more severe disease stage compared with those who did not.
Eighteen months after baseline, participants underwent comprehensive cognitive testing and diagnostic review, provided an 80 ml blood sample, and completed health and lifestyle questionnaires. A subgroup also underwent amyloid PET and MRI neuroimaging.
The diagnostic status of 89.9% of the cohorts was determined (972 were reassessed, 28 had died, and 112 did not return for reassessment). The 18-month cohort comprised 692 HCs, 82 MCI cases, 197 AD patients, and one Parkinson's disease dementia case. The transition rate from HC to MCI was 2.5%, and cognitive decline in HCs who transitioned to MCI was greatest in memory and naming domains compared to HCs who remained stable. The transition rate from MCI to AD was 30.5%.
There was a high retention rate after 18 months. Rates of transition from healthy aging to MCI, and MCI to AD, were consistent with established estimates. Follow-up of this cohort over longer periods will elucidate robust predictors of future cognitive decline.
T lymphocytes are a key regulatory component of the adaptive immune system. Understanding how the micro- and nano-scale details of the extracellular environment influence T cell activation may have wide impact on the use of T cells for therapeutic purposes. In this article, we examine how the micro- and nano-scale presentation of ligands to cell surface receptors, including microscale organization and nanoscale mobility, influences the activation of T cells. We extend these studies to include the role of cell-generated forces, and the rigidity of the microenvironment, on T cell activation. These approaches enable delivery of defined signals to T cells, a step toward understanding the cell-cell communication in the immune system, and developing micro/nano- and material- engineered systems for tailoring immune responses for adoptive T cell therapies.
In 2008 we compared numbers of emerald ash borer, Agrilus planipennis Fairmaire, captured on glue-coated prism traps of different sizes (standard, double-length narrow, and quarter), colors (green and purple), and height in relation to the canopy of ash host trees (midcanopy (10–13 m) and ground level (1.5 m)). Standard-size prism traps caught more A. planipennis than did quarter-size prism traps, but catch per square metre of surface area did not differ significantly among the three trap sizes. Twenty percent of quarter-size prism traps failed to catch a single beetle, while all traps of the two larger sizes were successful. The larger traps therefore appear to be more useful as detection tools. In 2009 we compared purple and green standard-size prism traps at three heights: midcanopy (13 m), lower canopy (6 m), and ground (1.5 m). Green traps caught more adult emerald ash borers than did purple traps in the mid and lower canopy, but there was no difference between traps hung at 1.5 m. The ratio of male to female adult emerald ash borers was also higher on green than on purple traps at all three heights.
A stillborn fetus with pulmonary valvar atresia and intact atrial and ventricular septums also had absence of coronary arterial connections from the aorta and an unroofed coronary sinus. A left superior caval vein drained to the dilated coronary sinus. The left coronary artery was anomalously connected to the proximal branch of the right pulmonary artery, and a fistula from the right ventricle supplied the right coronary artery.
From conception to death, helping relationships promote positive development and enable people to surmount challenges in their lives. Is it the case that the negative consequences of a genetic propensity for risky behaviors can be attenuated by helping relationships (a G × E)? But is it also the case that people with such a genetic propensity are less likely to have helping relationships compared to people without such a propensity (a rGE)? We illustrate this complex pattern of gene–environment interplay by drawing on the National Longitudinal Study of Adolescent Health and a combinatoric analytic strategy. We focus on a gene associated with dopamine receptor type 2 (DRD2 TaqIA), student–mentor relationships, and educational continuation beyond secondary school. Results reveal that, for both white and black males, DRD2 A1+ (A1A1 and A1A2 genotypes) is associated with a decreased likelihood of school continuation compared to their counterparts with DRD2 A1–; mentors who are teachers compensate for this negative association (a G × E); and youth with DRD2 A1+ are less likely to have a mentor who is a teacher than their counterparts with DRD2 A1– (a rGE).
Purified single-walled nanotubes (SWNTs) were dispersed in an epoxy polymer and subjected to uniaxial compressive loading. The orientation and stress in the nanotubes were monitored in situ using polarized Raman microscopy. At strains less than 2%, the nanotubes reorient normal to the direction of compression, thereby minimizing the local strain energy. Above 2% strain, the Raman peak shift reaches a plateau. A new analytical model, which approximates the SWNT reorientation by varying the aspect ratio of a representative spheroid, predicted the rotation behavior of nanotubes under load. The results of this model suggest that the observed plateau of the Raman peak shift is caused by both polymer yielding and interfacial debonding at the ends of nanotubes.
To determine the prevalence of central venous catheter (CVC) use among patients both within and outside the ICU setting.
A 1-day prevalence survey of CVC use among adult inpatients at six medical centers participating in the Prevention Epicenter Program of the CDC. Using a standardized form, observers at each Epicenter performed a hospital-wide survey, collecting data on CVC use.
Inpatient wards and ICUs of six large urban teaching hospitals.
At the six medical centers, 2,459 patients were surveyed; 29% had CVCs. Among the hospitals, from 43% to 80% (mean, 59.3%) of ICU patients and from 7% to 39% (mean, 23.7%) of non-ICU patients had CVCs. Despite the lower rate of CVC use on non-ICU wards, the actual number of CVCs outside the ICUs exceeded that of the ICUs. Most catheters were inserted in the subclavian (55%) or jugular (22%) site, with femoral (6%) and peripheral (15%) sites less commonly used. The jugular (33.0% vs 16.6%; P < .001) and femoral (13.8% vs 2.7%; P < .001) sites were more frequently used in ICU patients, whereas peripherally inserted (19.9% vs 5.9%; P < .001) and subclavian (60.7% vs 47.3%; P < .001) catheters were more commonly used in non-ICU patients.
Current surveillance and infection control efforts to reduce morbidity and mortality associated with bloodstream infections concentrate on the high-risk ICU patients with CVCs. Our survey demonstrated that two-thirds of identified CVCs were not in ICU patients and suggests that more efforts should be directed to patients with CVCs who are outside the ICU.
Deformation and breakup of drops in an isotropic turbulent flow has been studied by numerical simulation. The numerical method involves a pseudospectral representation of the turbulent outer flow field coupled to three-dimensional boundary integral simulations of the local drop dynamics. A statistical analysis based on an ensemble of drop trajectories is presented; results include breakup rates, the distribution of primary daughter drops produced by breakup events, and stationary distributions for drop deformation and orientation. Depending on the local flow history, drops may break at modest length or become highly elongated and relax without breaking. Drop deformation is the dominant mechanism of drop reorientation. The volume of the primary daughter drops, produced by a given fluctuation in flow strength, scales with the volume of the corresponding critical drop size for the fluctuation. A simplified description for the evolution of the drop size distribution, based on this scaling, is presented.
Email your librarian or administrator to recommend adding this to your organisation's collection.