Disastrous bushfires during the last months of 2019 and January 2020 affected Australia, raising the question to what extent the risk of these fires was exacerbated by anthropogenic climate change. ...To answer the question for southeastern Australia, where fires were particularly severe, affecting people and ecosystems, we use a physically based index of fire weather, the Fire Weather Index; long-term observations of heat and drought; and 11 large ensembles of state-of-the-art climate models. We find large trends in the Fire Weather Index in the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Atmospheric Reanalysis (ERA5) since 1979 and a smaller but significant increase by at least 30 % in the models. Therefore, we find that climate change has induced a higher weather-induced risk of such an extreme fire season. This trend is mainly driven by the increase of temperature extremes. In agreement with previous analyses we find that heat extremes have become more likely by at least a factor of 2 due to the long-term warming trend. However, current climate models overestimate variability and tend to underestimate the long-term trend in these extremes, so the true change in the likelihood of extreme heat could be larger, suggesting that the attribution of the increased fire weather risk is a conservative estimate. We do not find an attributable trend in either extreme annual drought or the driest month of the fire season, September–February. The observations, however, show a weak drying trend in the annual mean. For the 2019/20 season more than half of the July–December drought was driven by record excursions of the Indian Ocean Dipole and Southern Annular Mode, factors which are included in the analysis here. The study reveals the complexity of the 2019/20 bushfire event, with some but not all drivers showing an imprint of anthropogenic climate change. Finally, the study concludes with a qualitative review of various vulnerability and exposure factors that each play a role, along with the hazard in increasing or decreasing the overall impact of the bushfires.
Magnetostriction, the strain induced by a change in magnetization, is a universal effect in magnetic materials. Owing to the difficulty in unraveling its microscopic origin, it has been largely ...treated phenomenologically. Here, we show how the source of magnetostriction-the underlying magnetoelastic stress-can be separated in the time domain, opening the door for an atomistic understanding. X-ray and electron diffraction are used to separate the sub-picosecond spin and lattice responses of FePt nanoparticles. Following excitation with a 50-fs laser pulse, time-resolved X-ray diffraction demonstrates that magnetic order is lost within the nanoparticles with a time constant of 146 fs. Ultrafast electron diffraction reveals that this demagnetization is followed by an anisotropic, three-dimensional lattice motion. Analysis of the size, speed, and symmetry of the lattice motion, together with ab initio calculations accounting for the stresses due to electrons and phonons, allow us to reveal the magnetoelastic stress generated by demagnetization.
ABSTRACT
Along their path from source to observer, gravitational waves may be gravitationally lensed by massive objects leading to distortion in the signals. Searches for these distortions amongst ...the observed signals from the current detector network have already been carried out, though there have as yet been no confident detections. However, predictions of the observation rate of lensing suggest detection in the future is a realistic possibility. Therefore, preparations need to be made to thoroughly investigate the candidate lensed signals. In this work, we present some follow-up analyses that could be applied to assess the significance of such events and ascertain what information may be extracted about the lens-source system by applying these analyses to a number of O3 candidate events, even if these signals did not yield a high significance for any of the lensing hypotheses. These analyses cover the strong lensing, millilensing, and microlensing regimes. Applying these additional analyses does not lead to any additional evidence for lensing in the candidates that have been examined. However, it does provide important insight into potential avenues to deal with high-significance candidates in future observations.
This paper presents an experimental study on concrete-filled circular tubes that consisted of seawater and sea sand concrete (SWSSC), stainless steel (SS) tube, carbon fibre reinforced polymer (CFRP) ...tube, and basalt fibre reinforced polymer (BFRP) tube. A total of 38 stub columns, which included 12 hollow section tubes, 12 fully SWSSC-filled tubes and 14 SWSSC-filled double-skin tubes, with four combinations of inner and outer tubes, were tested under axial compression. Tensile coupon tests and “disk-split” tests were conducted to obtain the material properties of SS, CFRP and BFRP. Ultimate strain of SWSSC-filled tubes and stress-strain curves of the confined concrete were characterised in the study. The effects of some key parameters (e.g., tube diameter-to-thickness ratio, cross-section types, outer tube types, and inner tube types) on the confinement effects were also discussed. Comparisons were made among CFRP, BFRP and glass fibre reinforced polymer (GFRP) in terms of confinement to SWSSC. The capacity prediction formulae previously proposed by the authors for SWSSC filled GFRP tubes were found to be reasonable for estimating the load carrying capacity of SWSSC filled CFRP and BFRP tubes.
•Material properties of seawater and sea sand concrete (SWSSC).•Stub column tests on SWSSC fully filled BFRP, CFRP and stainless steel tubes.•Stub column tests on SWSSC filled double skin BFRP, CFRP and stainless steel tubes.•Comparison of concrete confinement provided by BFRP, CFRP and GFRP tubes.•Capacity formulae for SWSSC filled BFRP, CFRP, GFRP and stainless steel tubes.
This study aimed to investigate role of long noncoding RNA PTENP1 regulating PTEN expression via miR-19b to affect breast cancer (BC) progression. We measured expressions of PTENP1, miR-19b and PTEN ...in 65 matched BC cancerous and noncancerous tissues by quantitative real-time fluorescence PCR (qRT-PCR) and investigated the biological effects of PTENP1 in BC MDA-MB-231 cells by several in vitro experiments including CCK8, wound healing, transwell and Annexin V-FITC/PI analysis. Besides, the competing endogenous RNA (ceRNA) activity of PTENP1 on miR-19b was detected by luciferase reporter assay, and the expressions of related genes and proteins were determined by western blot assay and qRT-PCR. Increased PTENP1 and PTEN and decreased miR-19b were observed in BC tissues and cell lines. Further, PTENP1 and PTEN are direct targets of miR-19b, and overexpressed PTENP1 in MDA-MB-231 cells could supress cell proliferation, migration and invasion and promote cell apoptosis. Moreover, PTENP1 could upregulate PTEN via its ceRNA interaction on miR-19b, as well as induced the upregulation of p53 and downregulation of p-AKT. Enhanced PTENP1 could inhibit BC cell growth, metastasis and tumourigenicity by inhibiting miR-19b and facilitating PTEN in BC, thereby may represent a novel target for diagnosis and treatment of BC.
The ultrafast laser excitation of matters leads to nonequilibrium states with complex solid-liquid phase-transition dynamics. We used electron diffraction at mega-electron volt energies to visualize ...the ultrafast melting of gold on the atomic scale length. For energy densities approaching the irreversible melting regime, we first observed heterogeneous melting on time scales of 100 to 1000 picoseconds, transitioning to homogeneous melting that occurs catastrophically within 10 to 20 picoseconds at higher energy densities. We showed evidence for the heterogeneous coexistence of solid and liquid. We determined the ion and electron temperature evolution and found superheated conditions. Our results constrain the electron-ion coupling rate, determine the Debye temperature, and reveal the melting sensitivity to nucleation seeds.
The advanced molybdenum-based rare process experiment (AMoRE) aims to search for neutrinoless double beta decay (
0
ν
β
β
) of
100
Mo with
∼
100
kg
of
100
Mo-enriched molybdenum embedded in cryogenic ...detectors with a dual heat and light readout. At the current, pilot stage of the AMoRE project we employ six calcium molybdate crystals with a total mass of 1.9 kg, produced from
48
Ca-depleted calcium and
100
Mo-enriched molybdenum (
48
depl
Ca
100
MoO
4
). The simultaneous detection of heat (phonon) and scintillation (photon) signals is realized with high resolution metallic magnetic calorimeter sensors that operate at milli-Kelvin temperatures. This stage of the project is carried out in the Yangyang underground laboratory at a depth of 700 m. We report first results from the AMoRE-Pilot
0
ν
β
β
search with a 111 kg day live exposure of
48
depl
Ca
100
MoO
4
crystals. No evidence for
0
ν
β
β
decay of
100
Mo is found, and a upper limit is set for the half-life of
0
ν
β
β
of
100
Mo of
T
1
/
2
0
ν
>
9.5
×
10
22
years
at 90% C.L. This limit corresponds to an effective Majorana neutrino mass limit in the range
⟨
m
β
β
⟩
≤
(
1.2
-
2.1
)
eV
.
Main effect elements of machining distortion for aluminum alloy and titanium alloy aircraft monolithic component are investigated by finite element simulation and experiment. Based on an analysis of ...milling process characters, finite element models of machining distortion are developed. Considering the action of initial residual stress, finite element simulation and analysis of machining distortion for aluminum alloy aircraft monolithic component are performed. Initial residual stress, cutting loads, and coupling action of these two effect factors are taken into account, respectively, to perform finite element simulations of machining distortion for titanium alloy aircraft monolithic component. The finite element simulation results are compared with experiment results and found to be in good agreement, indicating the validation of the proposed finite element models. The research results show that the initial residual stress in the blank is the main effect element of machining distortion for aluminum alloy aircraft monolithic component, while cutting loads (including cutting force and temperature) are the main effect element of machining distortion for titanium alloy aircraft monolithic component. To decrease machining distortion of aluminum alloy aircraft monolithic component, the initial residual stress in the blank must be controlled first. Similarly, to decrease machining distortion of titanium alloy aircraft monolithic component, the cutting loads must be controlled first.
Hepatoblastoma is the most common liver tumor of early childhood, which is usually characterized by unusual hypervascularity. Recently, long non-coding RNAs (lncRNA) have emerged as gene regulators ...and prognostic markers in several cancers, including hepatoblastoma. We previously reveal that lnRNA-TUG1 is upregulated in hepatoblastoma specimens by microarray analysis. In this study, we aim to elucidate the biological and clinical significance of TUG1 upregulation in hepatoblastoma. We show that TUG1 is significantly upregulated in human hepatoblastoma specimens and metastatic hepatoblastoma cell lines. TUG1 knockdown inhibits tumor growth and angiogenesis in vivo, and decreases hepatoblastoma cell viability, proliferation, migration, and invasion in vitro. TUG1, miR-34a-5p, and VEGFA constitutes to a regulatory network, and participates in regulating hepatoblastoma cell function, tumor progression, and tumor angiogenesis. Overall, our findings indicate that TUG1 upregulation contributes to unusual hypervascularity of hepatoblastoma. TUG1 is a promising therapeutic target for aggressive, recurrent, or metastatic hepatoblastoma.
The radiant energy budget and internal heat are fundamental properties of giant planets, but precise determination of these properties remains a challenge. Here, we report measurements of Jupiter's ...radiant energy budget and internal heat based on Cassini multi-instrument observations. Our findings reveal that Jupiter's Bond albedo and internal heat, 0.503 ± 0.012 and 7.485 ± 0.160 W m
respectively, are significantly larger than 0.343 ± 0.032 and 5.444 ± 0.425 Wm
, the previous best estimates. The new results help constrain and improve the current evolutionary theories and models for Jupiter. Furthermore, the significant wavelength dependency of Jupiter's albedo implies that the radiant energy budgets and internal heat of the other giant planets in our solar system should be re-examined. Finally, the data sets of Jupiter's characteristics of reflective solar spectral irradiance provide an observational basis for the models of giant exoplanets.
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