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

Tentative Evidence for Relativistic Electrons Generated by the Jet of the Young Sun-like Star DG Tau

Synchrotron emission has recently been detected in the jet of a massive protostar, providing further evidence that certain jet formation characteristics for young stars are similar to those found for highly relativistic jets from AGN. We present data at 325 and 610 MHz taken with the GMRT of the young, low-mass star DG Tau, an analog of the Sun soon after its birth. This is the first investigation of a low-mass YSO at at such low frequencies. We detect emission with a synchrotron spectral index in the proximity of the DG Tau jet and interpret this emission as a prominent bow shock associated with this outflow. This result provides tentative evidence for the acceleration of particles to relativistic energies due to the shock impact of this otherwise very low-power jet against the ambient medium. We calculate the equipartition magnetic field strength (0.11 mG) and particle energy (4x10^40 erg), which are the minimum requirements to account for the synchrotron emission of the DG Tau bow shock. These results suggest the possibility of low energy cosmic rays being generated by young Sun-like stars.Comment: 19 pages, 2 figures, accepted for publication in ApJ Letter

Probing self-interacting sterile neutrino dark matter with the diffuse supernova neutrino background

The neutrinos in the diffuse supernova neutrino background (DSNB) travel over cosmological distances and this provides them with an excellent opportunity to interact with dark relics. We show that a cosmologically-significant relic population of keV-mass sterile neutrinos with strong self-interactions could imprint their presence in the DSNB. The signatures of the self-interactions would be ``dips" in the otherwise smooth DSNB spectrum. Upcoming large-scale neutrino detectors, for example Hyper-Kamiokande, have a good chance of detecting the DSNB and these dips. If no dips are detected, this method serves as an independent constraint on the sterile neutrino self-interaction strength and mixing with active neutrinos. We show that relic sterile neutrino parameters that evade X-ray and structure bounds may nevertheless be testable by future detectors like TRISTAN, but may also produce dips in the DSNB which could be detectable. Such a detection would suggest the existence of a cosmologically-significant, strongly self-interacting sterile neutrino background, likely embedded in a richer dark sector.Comment: 10 pages, 2 figures. Clarifying changes, matches version published in Phys. Rev.

Analysis of the gene coding for the BRCA2-Interacting protein PALB2 in hereditary prostate cancer

BACKGROUND The genetic basis of susceptibility to prostate cancer (PRCA) remains elusive. Mutations in BRCA2 have been associated with increased prostate cancer risk and account for around 2% of young onset (<56 years) prostate cancer cases. PALB2 is a recently identified breast cancer susceptibility gene whose protein is closely associated with BRCA2 and is essential for BRCA2 anchorage to nuclear structures. This functional relationship made PALB2 a candidate PRCA susceptibility gene. METHODS We sequenced PALB2 in probands from 95 PRCA families, 77 of which had two or more cases of early onset PRCA (age at diagnosis <55 years), and the remaining 18 had one case of early onset PRCA and five or more total cases of PRCA. RESULTS Two previously unreported variants, K18R and V925L were identified, neither of which is in a known PALB2 functional domain and both of which are unlikely to be pathogenic. No truncating mutations were identified. CONCLUSIONS These results indicate that deleterious PALB2 mutations are unlikely to play a significant role in hereditary prostate cancer. Prostate 68: 675–678, 2008. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58069/1/20729_ftp.pd

Evidence of topological superconductivity in planar Josephson junctions

Majorana zero modes are quasiparticle states localized at the boundaries of topological superconductors that are expected to be ideal building blocks for fault-tolerant quantum computing. Several observations of zero-bias conductance peaks measured in tunneling spectroscopy above a critical magnetic field have been reported as experimental indications of Majorana zero modes in superconductor/semiconductor nanowires. On the other hand, two dimensional systems offer the alternative approach to confine Ma jorana channels within planar Josephson junctions, in which the phase difference {\phi} between the superconducting leads represents an additional tuning knob predicted to drive the system into the topological phase at lower magnetic fields. Here, we report the observation of phase-dependent zero-bias conductance peaks measured by tunneling spectroscopy at the end of Josephson junctions realized on a InAs/Al heterostructure. Biasing the junction to {\phi} ~ {\pi} significantly reduces the critical field at which the zero-bias peak appears, with respect to {\phi} = 0. The phase and magnetic field dependence of the zero-energy states is consistent with a model of Majorana zero modes in finite-size Josephson junctions. Besides providing experimental evidence of phase-tuned topological superconductivity, our devices are compatible with superconducting quantum electrodynamics architectures and scalable to complex geometries needed for topological quantum computing.Comment: main text and extended dat

Molecular and clinical determinants of response and resistance to rucaparib for recurrent ovarian cancer treatment in ARIEL2 (Parts 1 and 2)

Càncer d'ovaris; Biomarcadors tumoralsCáncer de ovarios; Biomarcadores tumoralesOvarian cancer; Tumour biomarkersARIEL2 (NCT01891344) is a single-arm, open-label phase 2 study of the PARP inhibitor (PARPi) rucaparib in relapsed high-grade ovarian carcinoma. In this post hoc exploratory biomarker analysis of pre- and post-platinum ARIEL2 samples, RAD51C and RAD51D mutations and high-level BRCA1 promoter methylation predict response to rucaparib, similar to BRCA1/BRCA2 mutations. BRCA1 methylation loss may be a major cross-resistance mechanism to platinum and PARPi. Genomic scars associated with homologous recombination deficiency are irreversible, persisting even as platinum resistance develops, and therefore are predictive of rucaparib response only in platinum-sensitive disease. The RAS, AKT, and cell cycle pathways may be additional modulators of PARPi sensitivity

Multi-stage, in-situ polymerisation for low-exotherm, liquid resin infusion of thick thermoplastic laminates at room temperature

This study exploits the unique attributes of a reactive thermoplastic acrylic resin system (room-temperature liquid-resin infusibility, in-situ polymerisability, and room-temperature weldability) to achieve additive-free mitigation of exothermic heat generation during thick laminate production. Additives are typically required when thicknesses exceed 12 mm, but their use often compromises the degree of polymerisation and mechanical performance. An innovative multi-stage manufacturing scheme has been used to achieve a 55 °C reduction in exothermic peak temperature during the production of a 16-mm-thick laminate compared to the use of a standard resin infusion (89 °C) for the same thickness. Laminates produced using the multi-stage scheme were also found to exhibit 24 % higher short-beam shear strengths than those obtained via standard resin infusion, suggesting improved part quality as an additional benefit. Further demonstrating the applicability of the proposed method, a 40-mm-thick laminate was successfully produced with a peak temperature of only 60 °C. This work highlights the potential of room-temperature welding for practical and low-cost production of ultra-thick laminates at room temperature

Pre-Prandial Vinegar Ingestion Improves Two-Hour Glucose Control in Older, Type II Diabetics More Than Post-Prandial Walking

Background: Exercise engagement benefits diabetic patients through an insulin-like effect on muscle. Literature indicates that vinegar consumption may lower blood glucose levels. It is not currently clarified whether a relative amount of vinegar ingestion or a walking bout is more effective at controlling glucose in older, Type II diabetics during the acute phase following a meal. Purpose: The aim was to directly compare the impact of preferred-pace walking (15 min, postprandial) versus ingestion of a relative quantity of vinegar (0.3 g/kg) on two-hour glucose control. Methods: The two arms of the trial were completed in a randomized, crossover manner. Six Type II diabetic patients (Females = 5; Males = 1; Age = 70.5 ± 9.0 yrs.) enrolled and underwent baseline finger pricks to establish glucose levels. The test meal consisted of an 85 g bagel, 13 g of butter, and 237 mL of orange juice. On the respective days, the vinegar was diluted into 59 mL of orange juice and ingested before the meal or the subject completed a 15-min walk at 15 min post-meal. For both trials, glucose was checked every 30 min following the test meal. Results: One subject was removed from all present analysis due to medication-related non-compliance. For the vinegar trial, the resting heart rate was 72.0 (± 9.5) and baseline, 30-, 60-, 90-, and 120-min average blood glucose levels were: 117 (±12), 149 (±39), 172 (±49), 185 (±49), and 180 (±44) mg/dl. For the preferred walking speed phase, the resting heart rate was 75.5 (±15.6) and baseline, 30-, 60-, 90-, and 120-min average glucose levels were: 113 (±10), 147 (±53), 180 (±53), 208 (±72), and 206 (±71) mg/dl. Preferred walking speed was found to average 3.1 (± 1.5) kph and total steps averaged 1418 (±376). The between-arm comparison of glucose at 120-min trended towards significance (p = 0.081). Conclusions: Compared with a bout of walking, a relative quantity of vinegar may serve as a more suitable mechanism for older Type II diabetics to control acute spikes in glucose after a high carbohydrate meal. With an adequately-powered analysis, between-arm comparisons at multiple time-points would likely have achieved statistical significance. Nevertheless, the meaningfulness of the glucose control exhibited should not be lost due to the lack of statistical significance. Finally, the slow absolute preferred walking pace of many older adults may undermine the ability for walking to result in sufficient energy expenditure capable of subsequent glucose control

Genetic polymorphisms in CYP17 , CYP3A4 , CYP19A1 , SRD5A2 , IGF-1 , and IGFBP-3 and prostate cancer risk in African-American men: The Flint Men's Health Study

BACKGROUND Association studies have examined the significance of several candidate genes based on biological pathways relevant to prostate carcinogenesis, including both the androgen and insulin-like growth factor pathways. Clinical and epidemiologic evidence suggest that androgens, specifically testosterone and dihydrotestosterone (DHT) are important not only in normal prostate growth but in the pathogenesis of prostate cancer. Similarly, the insulin-like growth factor-1 (IGF-1) signaling pathway regulates both cellular proliferation and apoptosis. Therefore, genes involved in the biosynthesis, activation, metabolism and degradation of androgens and the stimulation of mitogenic and antiapoptotic activities of prostate epithelial cells represent important candidates for affecting the development and progression of prostate cancer. METHODS Using resources from the Flint Men's Health Study, a population-based case control study of African-American men aged 40–79, we evaluated the associations between selected single-nucleotide polymorphisms (SNPs) in the CYP17 , CYP3A4 , CYP19A1 , SDR5A2 , IGF1 , and IGFBP3 genes and prostate cancer diagnosis in 473 men (131 prostate cancer cases and 342 disease-free controls). RESULTS We found a significant association between prostate cancer and selected CYP17 SNP genotypes, with the heterozygous genotype conferring decreased risk. Suggestive evidence for association between IGF1 SNPs and prostate cancer were also found. No significant associations were observed between SNPs in the other genes and prostate cancer. CONCLUSIONS These findings suggest that variation in or around CYP17 and/or IGF1 may be associated with prostate cancer development in the African-American population. Additional studies are needed to determine whether these polymorphisms are indeed associated with prostate cancer risk in African Americans. Prostate 68: 296–305, 2008. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57913/1/20696_ftp.pd