415,987 research outputs found
Galaxy And Mass Assembly (GAMA) : galaxy close pairs, mergers and the future fate of stellar mass
No full textASGR acknowledges STFC and SUPA funding that were used to do this work. GAMA is funded by the STFC (UK), the ARC (Australia), the AAO and the participating institutions.We use a highly complete subset of the Galaxy And Mass Assembly II (GAMA-II) redshift sample to fully describe the stellar mass dependence of close pairs and mergers between 10(8) and 10(12)M(circle dot). Using the analytic form of this fit we investigate the total stellar mass accreting on to more massive galaxies across all mass ratios. Depending on how conservatively we select our robust merging systems, the fraction of mass merging on to more massive companions is 2.0-5.6 per cent. Using the GAMA-II data we see no significant evidence for a change in the close pair fraction between redshift z = 0.05 and 0.2. However, we find a systematically higher fraction of galaxies in similar mass close pairs compared to published results over a similar redshift baseline. Using a compendium of data and the function gamma(M) = A(1 + z)(m) to predict the major close pair fraction, we find fitting parameters of A = 0.021 +/- 0.001 and m = 1.53 +/- 0.08, which represents a higher low-redshift normalization and shallower power-law slope than recent literature values. We find that the relative importance of in situ star formation versus galaxy merging is inversely correlated, with star formation dominating the addition of stellar material below M* and merger accretion events dominating beyond M*. We find mergers have a measurable impact on the whole extent of the galaxy stellar mass function (GSMF), manifest as a deepening of the 'dip' in the GSMF over the next similar to Gyr and an increase in M* by as much as 0.01-0.05 dex.Peer reviewe
Close-aperture Z-scan signals for the concentration at 100 x10<sup>-5</sup> M of the three dyes A1, A2 and A3.
No full textClose-aperture Z-scan signals for the concentration at 100 x10-5 M of the three dyes A1, A2 and A3.</p
A BRANCHED-CHAIN AMINO ACID AMINOTRANSFERASE GENE ISOLATED FROM HORDEUM VULGARE IS DIFFERENTIALLY REGULATED BY DROUGHT STRESS
No full textDifferential display was used to isolate cDNA clones showing differential expression in response to ABA, drought and cold in barley seedling shoots. One drought-regulated cDNA clone (DD12) was further analyzed and found to encode a branched-chain
amino acid aminotransferase (HvBCAT-1). A genomic clone was isolated by probing the Morex BAC library with the cDNA clone DD12 and the structure of Hvbcat-1 was elucidated. The coding region is interrupted by six introns and contains a predicted mitochondrial
transit peptide. Hvbcat1 was mapped to chromosome 4H. A comparison was made to rice and Arabidopsis genes to identify conserved structural patterns. Complementation of a yeast (Saccharomyces cerevisiae) double knockout strain revealed that HvBCAT-1 can function as the mitochondrial (catabolic) BCATs in vivo. Transcript levels of Hvbcat-1, increased in response to drought stress. As the first enzyme in the branched-chain amino acid (BCAA)
catabolic pathway, HvBCAT-1 might have a role in the degradation of BCAA. Degradation of BCAA could serve as a detoxification mechanism that maintains the pool of free branched-chain amino acids at low and non toxic levels, under drought stress conditions
Adaptive optics with an infrared Pyramid wavefront sensor
No full textWavefront sensing in the infrared is highly desirable for the study of M-type stars and cool red objects, as they are sufficiently bright in the infrared to be used as the adaptive optics guide star. This aids in high contrast imaging, particularly for low mass stars where the star-to-planet brightness ratio is reduced. Here we discuss the combination of infrared detector technology with the highly sensitive Pyramid wavefront sensor (WFS) for a new generation of systems. Such sensors can extend the capabilities of current telescopes and meet the requirements for future instruments, such as those proposed for the giant segmented mirror telescopes. Here we introduce the infrared Pyramid WFS and discuss the advantages and challenges of this sensor. We present a new infrared Pyramid WFS for Keck, a key sub-system of the Keck Planet Imager and Characterizer (KPIC). The design, integration and testing is reported on, with a focus on the characterization of the SAPHIRA detector used to provide the H-band wavefront sensing. Initial results demonstrate a required effective read noise <1e^– at high gain
Gender differences in self-reported late effects, quality of life and satisfaction with clinic in survivors of lymphoma
No full textObjectives: gender differences in perceived vulnerability to late effects and views about follow-up among cancer survivors have received little attention. As lymphoma affects both genders similarly, we compared the consequences of cancer (late effects, perceived vulnerability and quality of life (health-related quality of life (HRQoL)), and satisfaction with clinic visits between genders.Methods: a cohort of 115 younger adults (18–45 years, >5 years disease-free survival), who had been treated for lymphoma participated. Questionnaires (n = 91) were completed before and after (n = 62) routine consultant-led appointments. Survivors (n = 24) without appointments were recruited by post. Questionnaires included HRQoL, late effects, perceived vulnerability, issues survivors wanted to discuss and reported discussing in clinic, time waiting in clinic and consultation satisfaction.Results: there were no gender differences in number of self-reported late effects or perceived vulnerability. Men with more late effects reported worse psychological HRQoL (r = 0.50, p<0.001). While men wanted to discuss more topics than they did, women were able to discuss the topics they wanted (ANOVA, p = 0.01). Multiple regression analyses showed a shorter wait in clinic (r = ?0.46, p = 0.009) and discussing more topics (r = 0.34, p = 0.06) explained 30.6% of the variance in consultation satisfaction for men.Conclusions: issues surrounding follow-up provision are increasingly important given the length of survival in young adults following treatment for lymphoma. Men may experience poor psychological well-being due to distress about unanswered concerns. Consideration of their concerns should be prioritised, given that satisfaction and ultimately continued attendance at clinic and HRQoL may be dependent on the extent to which follow-up meets survivors' expectation
A BRANCHED-CHAIN AMINO ACID AMINOTRANSFERASE ISOLATED FROM HORDEUM VULGARE IS DIFFERENTIALLY REGULATED BY ABIOTIC STRESS
No full textNear-infrared wavefront sensing
No full textWe discuss the advantages of wavefront sensing at near-infrared (IR) wavelengths with low-noise detector technologies that have recently become available. In this paper, we consider low order sensing with laser guide star (LGS) adaptive optics (AO) and high order sensing with natural guide star (NGS) AO. We then turn to the application of near-IR sensing with the W. M. Keck Observatory (WMKO) AO systems for science and as a demonstrator for similar systems on extremely large telescopes (ELTs). These demonstrations are based upon an LGS AO near-IR tip-tilt-focus sensor and our collaboration to implement a near-IR pyramid wavefront sensor (PWFS) for a NGS AO L-band coronagraphic imaging survey to identify exoplanet candidates
Novel Details of Calsequestrin Gel Conformation in Situ
No full textCalsequestrin (CASQ) is the major component of the sarcoplasmic reticulum (SR) lumen in skeletal and cardiac muscles. This calcium-binding protein localizes to the junctional SR (jSR) cisternae, where it is responsible for the storage of large amounts of Ca2+, whereas it is usually absent, at least in its polymerized form, in the free SR. The retention of CASQ inside the jSR is due partly to its association with other jSR proteins, such as junctin and triadin, and partly to its ability to polymerize, in a high Ca2+ environment, into an intricate gel that holds the protein in place. In this work, we shed some light on the still poorly described in situ structure of polymerized CASQ using detailed EM images from thin sections, with and without tilting, and from deep-etched rotary-shadowed replicas. The latter directly illustrate the fundamental network nature of polymerized CASQ, revealing repeated nodal points connecting short segments of the linear polymer. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A
- …
