We outline a proposal to use the Kepler spacecraft in two-wheel mode to monitor a handful of young associations and open clusters, for a few weeks each. Judging from the experience of similar ...projects using ground-based telescopes and the CoRoT spacecraft, this program would transform our understanding of early stellar evolution through the study of pulsations, rotation, activity, the detection and characterisation of eclipsing binaries, and the possible detection of transiting exoplanets. Importantly, Kepler's wide field-of-view would enable key spatially extended, nearby regions to be monitored in their entirety for the first time, and the proposed observations would exploit unique synergies with the GAIA ESO spectroscopic survey and, in the longer term, the GAIA mission itself. We also outline possible strategies for optimising the photometric performance of Kepler in two-wheel mode by modelling pixel sensitivity variations and other systematics.
Background Anaplastic large-cell lymphoma (ALCL) is a recently recognized, distinctive type of non-Hodgkin's lymphoma characterized by anaplastic large-cell cytology and expression of a member of the ...TNF-receptor family CD30. A characteristic chromosomal translocation has been identified in ALCL of T-or null-cell lineage which juxtaposes a novel tyrosine kinase (anaplastic lymphoma kinase, ALK) located at 2p23 with the nucleophosmin gene (NPM) at 5q35. A chimeric mRNA transcript is produced, and the translocation results in constitutive expression of a truncated form of the ALK protein, p80. There is controversy concerning whether or not the translocation occurs in Hodgkin's disease. The aim of this study was to develop a methodology for fluorescent in situ hybridization (FISH) to detect the t(2;5)(p23;q35), and to compare the results with conventional cytogenetics, reverse-transcriptase PCR and immunostaining for the p80 protein. Patients and methods Twenty-five cases of malignant lymphoma (11 ALCL and 14 HD) were studied. Immunohistochemistry was performed to confirm the diagnosis and for analysis of p80 expression. Conventional cytogenetics were analyzed on G-banded metaphase spreads. FISH was performed using whole chromosome paints for chromosomes 2 and 5 on metaphase spreads and YAC probes for interphase nuclei. Reverse-transcriptase PCR using primers for ALK and NPM was used to amplify the translocation breakpoint in extracted mRNA. Results Among 11 cases of ALCL examined by FISH, the translocation was detected in 4. Two of these cases also had RT-PCR and p80 staining performed, with positive results. Among 7 cases where the t(2;5) was not detected by FISH, 3 cases were examined by RT-PCR with negative results and 4 cases by p80 staining, also negative. The RT-PCR was negative in all 14 cases of Hodgkin's disease, 4 of which were also examined by FISH and found to be negative. Conclusion Fluorescent in situ hybridization is a useful method for detection of the t(2;5)(p23;q35) in anaplastic large-cell lymphoma. The results concur with those of RT-PCR for the chimeric transcript and immunostaining for the p80 protein. The frequency with which the translocation was found was 36% in this small series, and no evidence of the translocation was found in cases of Hodgkin's disease.
Innovative Science Braben, Donald W; Allen, John F; Amos, William ...
arXiv (Cornell University),
09/2015
Paper, Journal Article
Odprti dostop
Sir, We write as senior scientists about a problem vital to the scientific enterprise and prosperity. Nowadays, funding is a lengthy and complex business. First, universities themselves must approve ...all proposals for submission. Funding agencies then subject those that survive to peer review, a process by which a few researchers, usually acting anonymously, assess a proposal's chances that it will achieve its goals, is the best value for money, is relevant to a national priority and will impact on a socio-economic problem. Only 25% of proposals received by the funding agencies are funded. These protracted processes force researchers to exploit existing knowledge, severely discourage open-ended studies and are hugely time-consuming. They are also new: before 1970, few researchers wrote proposals. Now they are virtually mandatory.
Over the summer of 2007, we obtained 1191 hours of `drift-scan' pulsar search observations with the Green Bank Telescope at a radio frequency of 350 MHz. Here we describe the survey setup, search ...procedure, and the discovery and follow-up timing of thirteen pulsars. Among the new discoveries, one (PSR J1623-0841) was discovered only through its single pulses, two (PSRs J1327-0755 and J1737-0814) are millisecond pulsars, and another (PSR J2222-0137) is a mildly recycled pulsar. PSR J1327-0755 is a 2.7 ms pulsar at a DM of 27.9 pc cm^{-3} in a 8.7 day orbit with a minimum companion mass of 0.22 solar mass. PSR J1737-0814 is a 4.2 ms pulsar at a DM of 55.3 pc cm^{-3} in a 79.3 day orbit with a minimum companion mass of 0.06 solar mass. PSR J2222-0137 is a 32.8 ms pulsar at a very low DM of 3.27 pc cm^{-3} in a 2.4 day orbit with a minimum companion mass of 1.11 solar mass. It is most likely a white dwarf-neutron star system or an unusual low-eccentricity double neutron star system. Ten other pulsars discovered in this survey are reported in the companion paper Lynch et al. 2012.
We have completed a 350 MHz drift scan survey using the Robert C. Byrd Green Bank Telescope with the goal of finding new radio pulsars, especially millisecond pulsars that can be timed to high ...precision. This survey covered ~10300 square degrees and all of the data have now been fully processed. We have discovered a total of 31 new pulsars, seven of which are recycled pulsars. A companion paper by Boyles et al. (2012) describes the survey strategy, sky coverage, and instrumental set-up, and presents timing solutions for the first 13 pulsars. Here we describe the data analysis pipeline, survey sensitivity, and follow-up observations of new pulsars, and present timing solutions for 10 other pulsars. We highlight several sources---two interesting nulling pulsars, an isolated millisecond pulsar with a measurement of proper motion, and a partially recycled pulsar, PSR J0348+0432, which has a white dwarf companion in a relativistic orbit. PSR J0348+0432 will enable unprecedented tests of theories of gravity.
The Green Bank Telescope (GBT) is the largest fully steerable radio telescope in the world and is one of our greatest tools for discovering and studying radio pulsars. Over the last decade, the GBT ...has successfully found over 100 new pulsars through large-area surveys. Here I discuss the two most recent---the GBT 350 MHz Drift-scan survey and the Green Bank North Celestial Cap survey. The primary science goal of both surveys is to find interesting individual pulsars, including young pulsars, rotating radio transients, exotic binary systems, and especially bright millisecond pulsars (MSPs) suitable for inclusion in Pulsar Timing Arrays, which are trying to directly detect gravitational waves. These two surveys have combined to discover 85 pulsars to date, among which are 14 MSPs and many unique and fascinating systems. I present highlights from these surveys and discuss future plans. I also discuss recent results from targeted GBT pulsar searches of globular clusters and Fermi sources.
The aim of this study was to test whether survival for patients with high-grade non-Hodgkin's lymphoma (NHL) can be improved with a non-cross-resistant regimen as compared to a CHOP-based regimen. ...This is a multicentre study comprising 325 adult patients, median age 58 years, with high-grade non-Hodgkin's lymphoma: patients of any age and performance status were eligible provided they were able to receive the drugs in the regimens. Patients were randomised to either B-CHOP-M (bleomycin, cyclophosphamide, doxorubicin, vincristine, prednisolone and methotrexate) or PEEC-M (methylprednisolone, vindesine, etoposide, chlorambucil and methotrexate) alternating with B-CHOP-M. At a median follow-up of 9 years, there was no significant difference in overall survival or disease-free survival between the two arms. Toxicities for the two regimens were equivalent. This study confirms that for relatively unselected patients with high-grade non-Hodgkin's lymphoma, an alternating multidrug regimen does not improve upon the results obtained with B-CHOP-M.
We describe a discrete event simulation model of the national liver allocation system. This model differs from previous modeling efforts in that it considers the natural history of the disease ...independently of any particular patient priority scheme, thus allowing an unbiased appraisal of various allocation schemes. We provide the basic structure of the model, which consists of patient and organ generators, a survival module, and a disease progression module. The model provides various outputs such as patient survival, financial cost, and the number of wasted organs. We describe our model of patient survival with and without a transplant. We discuss some difficulties estimating model parameters due to a lack of appropriate medical data, and how these difficulties were overcome. We close with conclusions and directions for further research.
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