A causal mechanism for childhood acute lymphoblastic leukaemia.

In this Review, I present evidence supporting a multifactorial causation of childhood acute lymphoblastic leukaemia (ALL), a major subtype of paediatric cancer. ALL evolves in two discrete steps. First, in utero initiation by fusion gene formation or hyperdiploidy generates a covert, pre-leukaemic clone. Second, in a small fraction of these cases, the postnatal acquisition of secondary genetic changes (primarily V(D)J recombination-activating protein (RAG) and activation-induced cytidine deaminase (AID)-driven copy number alterations in the case of ETS translocation variant 6 (ETV6)-runt-related transcription factor 1 (RUNX1) + ALL) drives conversion to overt leukaemia. Epidemiological and modelling studies endorse a dual role for common infections. Microbial exposures earlier in life are protective but, in their absence, later infections trigger the critical secondary mutations. Risk is further modified by inherited genetics, chance and, probably, diet. Childhood ALL can be viewed as a paradoxical consequence of progress in modern societies, where behavioural changes have restrained early microbial exposure. This engenders an evolutionary mismatch between historical adaptations of the immune system and contemporary lifestyles. Childhood ALL may be a preventable cancer

Coalescence of a single droplet at a liquid–liquid interface

The coalescence of single drops at a plane liquid–liquid interface has been studied both theoretically and experimentally. Experiments were carried out with a wide range of drop size using two and three component systems. The drops coalesced in a partial manner and the drop size ratios between stages were determined. A detailed examination is made of the rest-time distributions for each stage of coalescence. Generally coalescence rest-times increased with increase in size of drop and fall height of the primary drop. Reasonable agreement between theory and experiment is approached for small drops. Coalescence rest-times of large drops were considerably less than predicted, presumably because of the deformation of the "trapped" film and uneven drainage. The variables affecting the coalescence are analysed and an empirical correlation is formulated to permit prediction of coalescence rest-times. Observations of the motion or the droplet fluid and the disturbed interface were carried out using Schlieren photography. The way in which wave disturbances at the interface can influence the coalescence process is examined. It is shown that that such wave disturbances may be responsible for the existence of the residence time distribution observed in all single drop coalescence studies

Understanding palliative care: An ethnographic study of three Australian palliative care services

Palliative care commenced in Australia in the early 1980s. Although the value of palliative care has become more widely recognised by the public and other health care professionals, there is still a lack of understanding about what palliative care is and the depth and scope of this specialty area of health care. The research that I present in this thesis is based on examination of palliative care practice in a selection of Australian services, undertaken with the aim of enhancing understanding of Palliative Care. The significance of the research arises from the notion that members of the Australian community should be well informed about health care options available to them. Understanding palliative care and the ability to differentiate palliative care from other end-of-life care is important if people are to make informed decisions about supporting, accessing, and using services appropriate to their needs. An interpretive ethnographic study from a symbolic interactionist perspective was undertaken in three palliative care services, one in each of the major Australian cities of Sydney. Melbourne, and Perth. Each palliative care service had been established for at least ten years, and was part of a larger health care facility. A fourth service, a purpose-built three-year-old unit, was added during the course of the research to provide contrast to the emerging analyses. As an experienced palliative care nurse, I assumed the role of marginal native as the primary research instrument. Data collection was by means of participant observation, formal and informal interviews, and examination of supplementary data sources, with two months spent in each of the three study sites. Interpretations made from ethnographic observation of these Australian palliative care services showed a diversity of practice, best understood within the context of the particular service. The major findings are presented under the headings of Politics, Place, People, and Practice of Palliative Care. Common approaches to provision of care were found in creating an appropriate physical environment for patients, with an underlying mission to make the best of things. Patients cared for in the settings were a similar cohort of middle aged to elderly cancer patients. In general, staff shared expectations of appropriate types of patients and showed discomfort or lack of understanding in caring for non-cancer patients, or patients from non-Australian, non-Christian, and non-English speaking backgrounds. Practice diversity was highlighted by the range of technology used and variations in the availability of social activities for patients in the services. These two: areas in particular warrant further research to examine the outcomes associated with these variations, in terms of survival time, quality of life, and service costs. These findings are particularly relevant at this time when the Australian Government is attempting to enhance access to palliative care. The diversity of practice uncovered in this study suggests that discussions and decisions about allocation of resources and development of services must take into consideration the various interpretations of palliative care services that may exist. The findings also reinforce the need for sound evidence-based studies to examine the impact of variations and the types of populations that might be best served by different types of palliative care support

Bearing Signal Separation of Commercial Helicopter Main Gearbox

Gears are significant component in a multiplicity of industrial applications such as machine tool and gearboxes. An unforeseen failure of gear may result in significant economic losses. Therefore this research propose fault detection improvement throught series of vibration signal processing techuiques. These techniques have been tested experimentally using vibration data collected from the transmission system of a CS-29 ‘Category A’ helicopter gearbox under different bearing damage severity of the second planetary stage. Results showed successful improvement of bearing fault detection

Coplanar Circumbinary Debris Disks

We present resolved Herschel images of circumbinary debris disks in the alpha CrB (HD139006) and beta Tri (HD13161) systems. We find that both disks are consistent with being aligned with the binary orbital planes. Though secular perturbations from the binary can align the disk, in both cases the alignment time at the distances at which the disk is resolved is greater than the stellar age, so we conclude that the coplanarity was primordial. Neither disk can be modelled as a narrow ring, requiring extended radial distributions. To satisfy both the Herschel and mid-IR images of the alpha CrB disk, we construct a model that extends from 1-300AU, whose radial profile is broadly consistent with a picture where planetesimal collisions are excited by secular perturbations from the binary. However, this model is also consistent with stirring by other mechanisms, such as the formation of Pluto-sized objects. The beta Tri disk model extends from 50-400AU. A model with depleted (rather than empty) inner regions also reproduces the observations and is consistent with binary and other stirring mechanisms. As part of the modelling process, we find that the Herschel PACS beam varies by as much as 10% at 70um and a few % at 100um. The 70um variation can therefore hinder image interpretation, particularly for poorly resolved objects. The number of systems in which circumbinary debris disk orientations have been compared with the binary plane is now four. More systems are needed, but a picture in which disks around very close binaries (alpha CrB, beta Tri, and HD 98800, with periods of a few weeks to a year) are aligned, and disks around wider binaries (99 Her, with a 50 yr period) are misaligned, may be emerging. This picture is qualitatively consistent with the expectation that the protoplanetary disks from which the debris emerged are more likely to be aligned if their binaries have shorter periods.Comment: accepted to MNRA

Sub-arcsecond high sensitivity measurements of the DG~Tau jet with e-MERLIN

We present very high spatial resolution deep radio continuum observations at 5 GHz (6 cm) made with e-MERLIN of the young stars DG Tau A and B. Assuming it is launched very close (~=1 au) from the star, our results suggest that the DG Tau A outflow initially starts as a poorly focused wind and undergoes significant collimation further along the jet (~=50 au). We derive jet parameters for DG Tau A and find an initial jet opening angle of 86 degrees within 2 au of the source, a mass-loss rate of 1.5x10^-8 solar masses/yr for the ionised component of the jet, and the total ejection/accretion ratio to range from 0.06-0.3. These results are in line with predictions from MHD jet-launching theories.Comment: Accepted MNRAS Letter

Grain legume adaptation to soil type

Grain legume adaptation to soil type, 89ME95, 89ME96, 89ME97, 89ME98, 89ME99, 89N36, 89N37. 89EB28, 89EB29, 89EB30, 89ME65. Lupin yield response to seed size and plant density, 89LG37, 89WH60, 89ME63, 89M2. Doublegee control in field peas with Bladex/MCPA, 89M31

Predicting the frequencies of diverse exo-planetary systems

Extrasolar planetary systems range from hot Jupiters out to icy comet belts more distant than Pluto. We explain this diversity in a model where the mass of solids in the primordial circumstellar disk dictates the outcome. The star retains measures of the initial heavy-element (metal) abundance that can be used to map solid masses onto outcomes, and the frequencies of all classes are correctly predicted. The differing dependences on metallicity for forming massive planets and low-mass cometary bodies are also explained. By extrapolation, around two-thirds of stars have enough solids to form Earth-like planets, and a high rate is supported by the first detections of low-mass exo-planets.Comment: 5 pages, 2 figures; accepted by MNRA