61 research outputs found
Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population
Mineral nutrient malnutrition, and particularly
deficiency in zinc and iron, afflicts over 3 billion people
worldwide. Wild emmer wheat, Triticum turgidum ssp.
dicoccoides, genepool harbors a rich allelic repertoire for
mineral nutrients in the grain. The genetic and physiological
basis of grain protein, micronutrients (zinc, iron,
copper and manganese) and macronutrients (calcium,
magnesium, potassium, phosphorus and sulfur) concentration
was studied in tetraploid wheat population of 152
recombinant inbred lines (RILs), derived from a cross
between durum wheat (cv. Langdon) and wild emmer
(accession G18-16). Wide genetic variation was found
among the RILs for all grain minerals, with considerable
transgressive effect. A total of 82 QTLs were mapped for
10 minerals with LOD score range of 3.2–16.7. Most QTLs
were in favor of the wild allele (50 QTLs). Fourteen pairs
of QTLs for the same trait were mapped to seemingly
homoeologous positions, reflecting synteny between the A
and B genomes. Significant positive correlation was found
between grain protein concentration (GPC), Zn, Fe and Cu,
which was supported by significant overlap between the
respective QTLs, suggesting common physiological and/or
genetic factors controlling the concentrations of these
mineral nutrients. Few genomic regions (chromosomes 2A,
5A, 6B and 7A) were found to harbor clusters of QTLs for
GPC and other nutrients. These identified QTLs may
facilitate the use of wild alleles for improving grain
nutritional quality of elite wheat cultivars, especially in
terms of protein, Zn and Fe
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Attribution: how is it relevant for loss and damage policy and practice?
Attribution has become a recurring issue in discussions about Loss and Damage (L&D). In this highly-politicised context, attribution is often associated with responsibility and blame; and linked to debates about liability and compensation. The aim of attribution science, however, is not to establish responsibility, but to further scientific understanding of causal links between elements of the Earth System and society. This research into causality could inform the management of climate-related risks through improved understanding of drivers of relevant hazards, or, more widely, vulnerability and exposure; with potential benefits regardless of political positions on L&D. Experience shows that it is nevertheless difficult to have open discussions about the science in the policy sphere. This is not only a missed opportunity, but also problematic in that it could inhibit understanding of scientific results and uncertainties, potentially leading to policy planning which does not have sufficient scientific evidence to support it. In this chapter, we first explore this dilemma for science-policy dialogue, summarising several years of research into stakeholder perspectives of attribution in the context of L&D. We then aim to provide clarity about the scientific research available, through an overview of research which might contribute evidence about the causal connections between anthropogenic climate change and losses and damages, including climate science, but also other fields which examine other drivers of hazard, exposure, and vulnerability. Finally, we explore potential applications of attribution research, suggesting that an integrated and nuanced approach has potential to inform planning to avert, minimise and address losses and damages. The key messages are
In the political context of climate negotiations, questions about whether losses and damages can be attributed to anthropogenic climate change are often linked to issues of responsibility, blame, and liability.
Attribution science does not aim to establish responsibility or blame, but rather to investigate drivers of change.
Attribution science is advancing rapidly, and has potential to increase understanding of how climate variability and change is influencing slow onset and extreme weather events, and how this interacts with other drivers of risk, including socio-economic drivers, to influence losses and damages.
Over time, some uncertainties in the science will be reduced, as the anthropogenic climate change signal becomes stronger, and understanding of climate variability and change develops.
However, some uncertainties will not be eliminated. Uncertainty is common in science, and does not prevent useful applications in policy, but might determine which applications are appropriate. It is important to highlight that in attribution studies, the strength of evidence varies substantially between different kinds of slow onset and extreme weather events, and between regions. Policy-makers should not expect the later emergence of conclusive evidence about the influence of climate variability and change on specific incidences of losses and damages; and, in particular, should not expect the strength of evidence to be equal between events, and between countries.
Rather than waiting for further confidence in attribution studies, there is potential to start working now to integrate science into policy and practice, to help understand and tackle drivers of losses and damages, informing prevention, recovery, rehabilitation, and transformation
GWTC-2.1: Deep extended catalog of compact binary coalescences observed by LIGO and Virgo during the first half of the third observing run
The second Gravitational-Wave Transient Catalog, GWTC-2, reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15 ∶ 00 UTC and 1 October 2019 15 ∶ 00 UTC. Here, we present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the probability of astrophysical origin for each candidate event. While GWTC-2 used a false alarm rate threshold of 2 per year, we include in GWTC-2.1, 1201 candidates that pass a false alarm rate threshold of 2 per day. We calculate the source properties of a subset of 44 high-significance candidates that have a probability of astrophysical origin greater than 0.5. Of these candidates, 36 have been reported in GWTC-2. We also calculate updated source properties for all binary black hole events previously reported in GWTC-1. If the eight additional high-significance candidates presented here are astrophysical, the mass range of events that are unambiguously identified as binary black holes (both objects ≥ 3 M⊙ ) is increased compared to GWTC-2, with total masses from ∼ 14 M ⊙ for GW190924_021846 to ∼ 182 M⊙ for GW190426_190642. Source properties calculated using our default prior suggest that the primary components of two new candidate events (GW190403_051519 and GW190426_190642) fall in the mass gap predicted by pair-instability supernova theory. We also expand the population of binaries with significantly asymmetric mass ratios reported in GWTC-2 by an additional two events (the mass ratio is less than 0.65 and 0.44 at 90% probability for GW190403_051519 and GW190917_114630 respectively), and find that two of the eight new events have effective inspiral spins χeff > 0 (at 90% credibility), while no binary is consistent with χeff < 0 at the same significance. We provide updated estimates for rates of binary black hole and binary neutron star coalescence in the local Universe
All-sky, all-frequency directional search for persistent gravitational waves from Advanced LIGO’s and Advanced Virgo’s first three observing runs
We present the first results from an all-sky all-frequency (ASAF) search for
an anisotropic stochastic gravitational-wave background using the data from the
first three observing runs of the Advanced LIGO and Advanced Virgo detectors.
Upper limit maps on broadband anisotropies of a persistent stochastic
background were published for all observing runs of the LIGO-Virgo detectors.
However, a broadband analysis is likely to miss narrowband signals as the
signal-to-noise ratio of a narrowband signal can be significantly reduced when
combined with detector output from other frequencies. Data folding and the
computationally efficient analysis pipeline, {\tt PyStoch}, enable us to
perform the radiometer map-making at every frequency bin. We perform the search
at 3072 {\tt{HEALPix}} equal area pixels uniformly tiling the sky and in every
frequency bin of width ~Hz in the range ~Hz, except for bins
that are likely to contain instrumental artefacts and hence are notched. We do
not find any statistically significant evidence for the existence of narrowband
gravitational-wave signals in the analyzed frequency bins. Therefore, we place
confidence upper limits on the gravitational-wave strain for each
pixel-frequency pair, the limits are in the range . In addition, we outline a method to identify candidate
pixel-frequency pairs that could be followed up by a more sensitive (and
potentially computationally expensive) search, e.g., a matched-filtering-based
analysis, to look for fainter nearly monochromatic coherent signals. The ASAF
analysis is inherently independent of models describing any spectral or spatial
distribution of power. We demonstrate that the ASAF results can be
appropriately combined over frequencies and sky directions to successfully
recover the broadband directional and isotropic results
Multi-wavelength characterization of the blazar S5~0716+714 during an unprecedented outburst phase
The BL Lac object S5~0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band. The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission. Multi-wavelength light curves have been studied together with the broadband Spectral Energy Distributions (SEDs). The data set collected spans from radio, optical photometry and polarimetry, X-ray, high-energy (HE, 0.1 GeV 100 GeV) with MAGIC. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the VHE. In the constructed SED the \textit{Swift}-XRT+\textit{NuSTAR} data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1~GeV to 600~GeV by \textit{Fermi}+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to -ray data. Instead we use a two-zone model. The EVPA shows an unprecedented fast rotation. An estimation of the redshift of the source by combined HE and VHE data provides a value of , confirming the literature value. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modelling
Multi-wavelength characterization of the blazar S5 0716+714 during an unprecedented outburst phase
Context. The BL Lac object S5 0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding to the brightest ever reported state of the source in the R-band.Aims.The comprehensive dataset collected is investigated in order to shed light on the mechanism of the broadband emission.Methods. Multi-wavelength light curves have been studied together with the broadband spectral energy distributions (SEDs). The sample includes data from Effelsberg, OVRO, Metsahovi, VLBI, CARMA, IRAM, SMA, Swift-UVOT, KVA, Tuorla, Steward, RINGO3, KANATA, AZT-8+ST7, Perkins, LX-200, Swift-XRT, NuSTAR, Fermi-LAT and MAGIC.Results. The flaring state of Phase A was detected in all the energy bands, providing for the first time a multi-wavelength sample of simultaneous data from the radio band to the very-high-energy (VHE, E> 100 GeV). In the constructed SED, the Swift-XRT +NuSTAR data constrain the transition between the synchrotron and inverse Compton components very accurately, while the second peak is constrained from 0.1 GeV to 600 GeV by Fermi+MAGIC data. The broadband SED cannot be described with a one-zone synchrotron self-Compton model as it severely underestimates the optical flux in order to reproduce the X-ray to y-ray data. Instead we use a two-zone model. The electric vector position angle (EVPA) shows an unprecedented fast rotation. An estimation of the redshift of the source by combined high-energy (HE, 0.1 GeV < E < 100 GeV) and VHE data provides a value of ,z = 0.31 +/- 0.02(stats) +/- 0.05(sys), confirming the literature value.Conclusions. The data show the VHE emission originating in the entrance and exit of a superluminal knot in and out of a recollimation shock in the inner jet. A shock-shock interaction in the jet seems responsible for the observed flares and EVPA swing. This scenario is also consistent with the SED modeling
A new era for understanding amyloid structures and disease
The aggregation of proteins into amyloid fibrils and their deposition into plaques and intracellular inclusions is the hallmark of amyloid disease. The accumulation and deposition of amyloid fibrils, collectively known as amyloidosis, is associated with many pathological conditions that can be associated with ageing, such as Alzheimer disease, Parkinson disease, type II diabetes and dialysis-related amyloidosis. However, elucidation of the atomic structure of amyloid fibrils formed from their intact protein precursors and how fibril formation relates to disease has remained elusive. Recent advances in structural biology techniques, including cryo-electron microscopy and solid-state NMR spectroscopy, have finally broken this impasse. The first near-atomic-resolution structures of amyloid fibrils formed in vitro, seeded from plaque material and analysed directly ex vivo are now available. The results reveal cross-β structures that are far more intricate than anticipated. Here, we describe these structures, highlighting their similarities and differences, and the basis for their toxicity. We discuss how amyloid structure may affect the ability of fibrils to spread to different sites in the cell and between organisms in a prion-like manner, along with their roles in disease. These molecular insights will aid in understanding the development and spread of amyloid diseases and are inspiring new strategies for therapeutic intervention
Search for gravitational waves associated with gamma-ray bursts detected by Fermi and Swift during the LIGO–Virgo run O3b
We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC–2020 March 27 17:00 UTC). We conduct two independent searches: a generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate
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