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Rate of photosynthetic induction in fluctuating light varies widely among genotypes of wheat.
Crop photosynthesis and yield are limited by slow photosynthetic induction in sunflecks. We quantified variation in induction kinetics across diverse genotypes of wheat for the first time. Following a preliminary study that hinted at wide variation in induction kinetics across 58 genotypes, we grew 10 genotypes with contrasting responses in a controlled environment and quantified induction kinetics of carboxylation capacity (Vcmax) from dynamic A versus ci curves after a shift from low to high light (from 50 µmol m-2 s-1 to 1500 µmol m-2 s-1), in five flag leaves per genotype. Within-genotype median time for 95% induction (t95) of Vcmax varied 1.8-fold, from 5.2 min to 9.5 min. Our simulations suggest that non-instantaneous induction reduces daily net carbon gain by up to 15%, and that breeding to speed up Vcmax induction in the slowest of our 10 genotypes to match that in the fastest genotype could increase daily net carbon gain by up to 3.4%, particularly for leaves in mid-canopy positions (cumulative leaf area index ≤1.5 m2 m-2), those that experience predominantly short-duration sunflecks, and those with high photosynthetic capacities
Space and surface power for the space exploration initiative: Results from project outreach
The analysis and evaluations of the Space and Surface Power panel, one of eight panels created by RAND to screen and analyze submissions to the Space Exploration Initiative (SEI) Outreach Program, is documented. In addition to managing and evaluating the responses, or submissions, to this public outreach program, RAND conducted its own analysis and evaluation relevent to SEI mission concepts, systems, and technologies. The Power panel screened and analyzed submissions for which a substantial portion of the concepts involved power generation sources, transmission, distribution, thermal management, and handling of power (including conditioning, conversion, packaging, and enhancements in system components). A background discussion of the areas the Power panel covered and the issues the reviewers considered pertinent to the analysis of power submissions are presented. An overview of each of the highest-ranked submissions and then a discussion of these submissions is presented. The results of the analysis is presented
Meeting the challenges of public engagement, research impact and research participation as a baby and child lab
As well as conducting research in developmental science, baby and child labs face additional pressures. They must demonstrate public engagement and research impact, while also recruiting enough participants to conduct research, something that can be particularly challenging with infants and young children. These different pressures compete for time and resources, leaving researchers struggling to engage effectively in all such activities. Here we describe a low-cost, easy-to-implement, enjoyable and effective means of simultaneously addressing the challenges of recruitment, public engagement and research impact. It started with a process of listening and knowledge exchange with relevant local stakeholders to discern the interests and needs of the local infant community (including families, health professionals and businesses). This process led to the establishment of a fortnightly educational and support group for pregnant women and mothers of young infants, which met in the lab. This group combined peer discussion, presentations on developmental psychology, and ‘taster’ activities for mothers and infants from local businesses. Data collected from questionnaires from the first and final sessions indicated significant improvements in participants’ understanding of relevant concepts in developmental psychology, and showed that participants found this information helpful and reported using it at home. Participants also reported feeling more socially connected and more confident as mothers as a result of the group. The group also served to boost research participation, with 94 per cent of participants subsequently taking part in lab research or signing up to be contacted about future research. This approach can be employed by baby and child labs looking for ways to effectively and enjoyably promote public engagement and research impact, and for those looking to establish strong relationships with local stakeholders. The success of this strategy demonstrates that the aims of recruitment, public engagement and research impact need not be competing pressures on researchers’ time, but can be mutually supporting aspects of the research process
Mass transport from the envelope to the disk of V346 Nor: a case study for the luminosity problem in an FUor-type young eruptive star
A long-standing open issue of the paradigm of low-mass star formation is the
luminosity problem: most protostars are less luminous than theoretically
predicted. One possible solution is that the accretion process is episodic. FU
Ori-type stars (FUors) are thought to be the visible examples for objects in
the high accretion state. FUors are often surrounded by massive envelopes,
which replenish the disk material and enable the disk to produce accretion
outbursts. However, we have insufficient information on the envelope dynamics
in FUors, about where and how mass transfer from the envelope to the disk
happens. Here we present ALMA observations of the FUor-type star V346 Nor at
1.3 mm continuum and in different CO rotational lines. We mapped the density
and velocity structure of its envelope and analyze the results using channel
maps, position-velocity diagrams, and spectro-astrometric methods. We found
that V346 Nor is surrounded by gaseous material on 10000 au scale in which a
prominent outflow cavity is carved. Within the central 700 au, the
circumstellar matter forms a flattened pseudo-disk where material is infalling
with conserved angular momentum. Within 350 au, the velocity profile is
more consistent with a disk in Keplerian rotation around a central star of 0.1
. We determined an infall rate from the envelope onto the disk of
610yr, a factor of few higher than the
quiescent accretion rate from the disk onto the star, hinting for a mismatch
between the infall and accretion rates as the cause of the eruption.Comment: 16 pages, 8 figures, published in Ap
Fast and Slow Rotators in the Densest Environments: a SWIFT IFS study of the Coma Cluster
We present integral-field spectroscopy of 27 galaxies in the Coma cluster
observed with the Oxford SWIFT spectrograph, exploring the kinematic
morphology-density relationship in a cluster environment richer and denser than
any in the ATLAS3D survey. Our new data enables comparison of the kinematic
morphology relation in three very different clusters (Virgo, Coma and Abell
1689) as well as to the field/group environment. The Coma sample was selected
to match the parent luminosity and ellipticity distributions of the early-type
population within a radius 15' (0.43 Mpc) of the cluster centre, and is limited
to r' = 16 mag (equivalent to M_K = -21.5 mag), sampling one third of that
population. From analysis of the lambda-ellipticity diagram, we find 15+-6% of
early-type galaxies are slow rotators; this is identical to the fraction found
in the field and the average fraction in the Virgo cluster, based on the
ATLAS3D data. It is also identical to the average fraction found recently in
Abell 1689 by D'Eugenio et al.. Thus it appears that the average slow rotator
fraction of early type galaxies remains remarkably constant across many
different environments, spanning five orders of magnitude in galaxy number
density. However, within each cluster the slow rotators are generally found in
regions of higher projected density, possibly as a result of mass segregation
by dynamical friction. These results provide firm constraints on the mechanisms
that produce early-type galaxies: they must maintain a fixed ratio between the
number of fast rotators and slow rotators while also allowing the total
early-type fraction to increase in clusters relative to the field. A complete
survey of Coma, sampling hundreds rather than tens of galaxies, could probe a
more representative volume of Coma and provide significantly stronger
constraints, particularly on how the slow rotator fraction varies at larger
radii.Comment: Accepted for publication in MNRA
Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1β in chondrocyte/agarose constructs
Introduction: The present study examined the effect of C-type natriuretic peptide (CNP) on the anabolic and catabolic activities in chondrocyte/agarose constructs subjected to dynamic compression. Methods: Constructs were cultured under free-swelling conditions or subjected to dynamic compression with low (0.1 to 100 pM) or high concentrations (1 to 1,000 nM) of CNP, interleukin-1? (IL-1?), and/or KT-5823 (inhibits cyclic GMP-dependent protein kinase II (PKGII)). Anabolic and catabolic activities were assessed as follows: nitric oxide (NO) and prostaglandin E2 (PGE2) release, and [3H]-thymidine and 35SO4 incorporation were quantified by using biochemical assays. Gene expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan, and collagen type II were assessed with real-time quantitative PCR (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t tests were used to examine data. Results: CNP reduced NO and PGE2 release and partially restored [3H]-thymidine and 35SO4 incorporation in constructs cultured with IL-1?. The response was dependent on the concentration of CNP, such that 100 pM increased [3H]-thymidine incorporation (P < 0.001). This is in contrast to 35SO4 incorporation, which was enhanced with 100 or 1000 nM CNP in the presence and absence of IL-1? (P < 0.001). Stimulation by both dynamic compression and CNP and/or the PKGII inhibitor further reduced NO and PGE2 release and restored [3H]-thymidine and 35SO4 incorporation. In the presence and absence of IL-1?, the magnitude of stimulation for [3H]-thymidine and 35SO4 incorporation by dynamic compression was dependent on the concentration of CNP and the response was inhibited with the PKGII inhibitor. In addition, stimulation by CNP and/or dynamic compression reduced IL-1?-induced iNOS and COX-2 expression and restored aggrecan and collagen type II expression. The catabolic response was not further influenced with the PKGII inhibitor in IL-1?-treated constructs. Conclusions: Treatment with CNP and dynamic compression increased anabolic activities and blocked catabolic effects induced by IL-1?. The anabolic response was PKGII mediated and raises important questions about the molecular mechanisms of CNP with mechanical signals in cartilage. Therapeutic agents like CNP could be administered in conjunction with controlled exercise therapy to slow the OA disease progression and to repair damaged cartilage. The findings from this research provide the potential for developing novel agents to slow the pathophysiologic mechanisms and to treat OA in the young and old. <br/
Light my elbows: a cycling jacket incorporating electronic yarn
There is a need for illuminated cycle clothing that is comfortable and safe when cycling, and stylish to wear during other activities. It is particularly challenging to integrate lighting within textiles without compromising the drape and comfort of the textile structure. A team of electronics, textiles and fashion specialists was formed to design and make an illuminated jacket for use by cyclists. The jacket incorporates bespoke woven panels that integrate electronic yarns within the pattern. These were designed and made for this project, with fluorescent and retroreflective yarns also included in the weave. LEDs integrated within the electronic yarns illuminate the elbows of the jacket, without causing constraint or adding excess volume. The movement of the jacket elbows during cycling widens the body outline and makes the lighting eye-catching.
The collaboration between electronics and textiles experts overcame challenges including development of electrical circuitry designed specifically to fit into the jacket unobtrusively, without interfering with movement or rucksack straps. Electrical connections were required between the electronic yarns assimilated within the weave. Standard, rigid solder joints would have been difficult to form without damaging the cloth and would have been liable to breakage within the garment structure, so embroidery techniques were used to create flexible, conductive connections.
The illuminated jacket provides a working prototype, demonstrating the potential for further collaborative ventures in which electronics are integrated into garments that are stylish, functional and 'wearable'. Further interdisciplinary research will include the development of additional wearable prototypes that enhance safety and wellbeing, whilst addressing the recycling of the textiles and garments, including the safe separation and disposal of electronic yarn and other components that provide electrical functionality
A fibre-coupled UHV-compatible variable angle reflection-absorption UV/visible spectrometer
We present a novel UV/visible reflection-absorption spectrometer for determining the refractive index, n, and thicknesses, d, of ice films. Knowledge of the refractive index of these films is of particular relevance to the astrochemical community, where they can be used to model radiative transfer and spectra of various regions of space. In order to make these models more accurate, values of n need to be recorded under astronomically relevant conditions, that is, under ultra-high vacuum (UHV) and cryogenic cooling. Several design considerations were taken into account to allow UHV compatibility combined with ease of use. The key design feature is a stainless steel rhombus coupled to an external linear drive (z-shift) allowing a variable reflection geometry to be achieved, which is necessary for our analysis. Test data for amorphous benzene ice is presented as a proof of concept, the film thickness, d, was found to vary linearly with surface exposure and a value for n of 1.43 ± 0.07 was determined
Extrapolation of survival curves using standard parametric models and flexible parametric spline models: comparisons in large registry cohorts with advanced cancer
Background:
It is often important to extrapolate survival estimates beyond the limited follow-up times of clinical trials. Extrapolated survival estimates can be highly sensitive to model choice; thus, appropriate model selection is crucial. Flexible parametric spline models have been suggested as an alternative to standard parametric models; however, their ability to extrapolate is not well understood.
Aim:
To determine how well standard parametric and flexible parametric spline models predict survival when fitted to registry cohorts with artificially right-censored follow-up times.
Methods:
Adults with advanced breast, colorectal, small cell lung, non–small cell lung, or pancreatic cancer with a potential follow-up time of 10 y were selected from the SEER 1973–2015 registry data set. Patients were classified into 15 cohorts by cancer and age group at diagnosis (18–59, 60–69, 70+ y). Follow-up times for each cohort were right censored at 20%, 35%, and 50% survival. Standard parametric models (exponential, Weibull, Gompertz, log-logistic, log-normal, generalized gamma) and spline models (proportional hazards, proportional odds, normal/probit) were fitted to the 10-y data set and the 3 right-censored data sets. Predicted 10-y restricted mean survival time and percentage surviving at 10 y were compared with the observed values.
Results:
Across all data sets, the spline odds and spline normal models most frequently gave accurate predictions of 10-y survival outcomes. Visually, spline models tended to demonstrate better fit to the observed hazard functions than standard parametric models, both in the censored and 10-y data.
Conclusions:
In these cohorts, where there was little uncertainty in the observed data, the spline models performed well when extrapolating beyond the observed data. Spline models should be routinely included in the set of models that are fitted when extrapolating cancer survival data
The Arecibo Arp 220 Spectral Census I: Discovery of the Pre-Biotic Molecule Methanimine and New Cm-wavelength Transitions of Other Molecules
An on-going Arecibo line search between 1.1 and 10 GHz of the prototypical
starburst/megamaser galaxy, Arp 220, has revealed a spectrum rich in molecular
transitions. These include the ``pre-biotic'' molecules: methanimine
(CHNH) in emission, three direct l-type absorption lines of
HCN, and an absorption feature likely to be from either OH or formic
acid (HCOOH). In addition, we report the detection of two, possibly three,
transitions of 4-cm excited OH not previously detected in Arp~220
which are seen in absorption, and a possible absorption feature from the
6.668-GHz line of methanol. This marks the first distant extragalactic
detection of methanimine, a pre-biotic molecule. Also, if confirmed, the
possible methanol absorption line presented here would represent the first
extragalactic detection of methanol at a distance further than 10 Mpc. In
addition, the strong, previously undetected, cm-wave HCN direct
l-type lines will aid the study of dense molecular gas and active star-forming
regions in this starburst galaxy.Comment: 25 pages, 10 figures. Accepted for publication in A
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