ABSTRACT
Accreting neutron stars (NSs) are one of the main targets for continuous gravitational wave searches, as asymmetric accretion may lead to quadrupolar deformations, or ‘mountains’, on the ...crust of the star, which source gravitational wave (GW) emission at twice the rotation frequency. The GW torque may also impact on the spin evolution of the star, possibly dictating the currently observed spin periods of NSs in low-mass X-ray binaries and leading to the increased spin-down rate observed during accretion in PSR J1023+0038. Previous studies have shown that deformed reaction layers in the crust of the NS lead to thermal and compositional gradients that can lead to GW emission. However, there are no realistic constraints on the level of asymmetry that is expected. In this paper, we consider a natural source of asymmetry, namely the magnetic field, and calculate the density and pressure perturbations that are expected in the crust of accreting NSs. In general, we find that only the outermost reaction layers of the NS are strongly perturbed. The mass quadrupole that we estimate is generally small and cannot explain the increase of spin-down rate of PSR J1023+0038. However, if strong shallow heating sources are present at low densities in the crust, as cooling observations suggest, these layers will be strongly perturbed and the resulting quadrupole could explain the observed spin-down of PSR J1023+0038, and lead to observable GW signals from systems with higher accretion rates.
This work deals with a comprehensive theoretical and numerical framework that allows the modeling of finite strain magnetorheological elastomers (MREs) comprising mechanically soft nonlinear ...elastic–viscoelastic polymer phases and magnetically hard (i.e. dissipative) or soft (i.e. purely energetic) magnetic phases. The framework is presented in a general manner and is implemented using the finite element method. Two software implementations are developed, one using FEniCS and the other in Abaqus. A detailed analysis of the numerical schemes used to model the surrounding air is made and their pros and cons are discussed. The proposed framework is used to simulate two model geometries that are directly relevant to recent applications of MREs. The first two-dimensional example simulates a mechanically soft beam consisting of a single wavy-chain of hard or soft magnetic particles. The beam is subjected to transverse magnetic actuation loads that induce important vertical deflections. Despite the overall small local strains in the beam, a significant viscoelastic effect is observed when high-rate magnetic fields are applied. A torque model for the particles is also used to analyze the beam geometry and is found to be in relatively good agreement with the rest of the approaches for small actuation fields. The second example discusses the rotation of a three-dimensional ellipsoid embedded in a cubic elastomer domain, while the ensemble lies inside a larger cubic air domain. Non-monotonic uniaxial and rotating magnetic fields are applied leading to complex, non-monotonic rotations of the ellipsoidal particle. The hard and soft magnetic cases exhibit significant differences, whereas viscoelasticity is found to induce strong coupling with the magnetization rotation but not with the dissipative magnetization amplitude. Extensive supplementary material provides all details of our implementations as well as animated visualization of results.
•2d coupled ferromagneto-viscoelastic response of a soft beam structure.•3d coupled ferromagneto-viscoelastic response of an ellipsoid in a soft matrix.•Assessment of various methods to account for the air surrounding the deformable bodies.•Codes for Abaqus and FEniCS implementations provided as supplementary material.
ABSTRACT
High-resolution radio observations of cluster radio relics often show complex spatial and spectral features. However, it is not clear what these features reveal about the underlying magnetic ...field properties. We performed three-dimensional magnetohydrodynamical simulations of merger shock waves propagating through a magnetized, turbulent intracluster medium. Our model includes the diffusive shock acceleration (DSA) of cosmic ray electrons, their spatial advection and energy losses at run-time. With this set-up we can investigate the relation between radio substructure and pre-shock plasma conditions in the host cluster. We find that upstream turbulence plays a major role in shaping the properties of radio relics produced downstream. Within the assumption of DSA, we can reproduce the observed discrepancy between the X-ray derived Mach number of shocks, and the Mach number inferred from radio spectra. Our simulated spectral index maps and profiles across the radio relic also suggest that the standard deviation of the upstream magnetic field must be relatively small ($\sigma _B\le 1 \, \mu$G) in order to reproduce observations and therefore radio relics can potentially constrain the distribution of magnetic fields in galaxy clusters outskirts.
Healthcare systems in Canada and elsewhere have identified the need to develop methods to effectively and safely transition appropriate cancer survivors to primary care. It is generally accepted that ...survivors with a low risk of adverse events, including recurrence and toxicity, should be more systematically identified and offered transition. There remains a lack of clarity about what constitutes an appropriate profile that would assist greater application in practice. To address this gap, we examined the clinical profiles of patients that were transitioned from a large regional cancer centre to the community. The factors examined included disease site, clinical stage, time since diagnosis/first consult, cancer treatments, and Edmonton Symptom Assessment System (ESAS) scores. In total, 2604 patients were identified as transitioned between 2013 and 2020. These patients tended to have common cancers (e.g., breast, endometrium, colorectal) that were generally of lower stage. Half of the patients had received chemotherapy and/or radiation treatment. Nearly one-third of survivors were transitioned within a year of first consult and a third after five years. Most patients reported minimal symptoms based on ESAS scores prior to being transitioned. This study represents one of the first to analyze the types of cancer patients that are being selected for transition to primary care.
We present new, spatially resolved CI1–0, CI2–1, CO(7–6), and dust continuum observations of 4C 41.17 at
z
= 3.8. This is one of the best-studied radio galaxies in this epoch and is arguably the ...best candidate of jet-triggered star formation at high redshift currently known in the literature. 4C 41.17 shows a narrow ridge of dust continuum extending over 15 kpc near the radio jet axis. Line emission is found within the galaxy in the region with signatures of positive feedback. Using the CI1–0 line as a molecular gas tracer, and multifrequency observations of the far-infrared dust heated by star formation, we find a total gas mass of 7.6 × 10
10
M
⊙
, which is somewhat greater than that previously found from CO(4–3). The gas mass surface density of 10
3
M
⊙
yr
−1
pc
−2
and the star formation rate surface density of 10
M
⊙
yr
−1
kpc
−2
were derived over the 12 kpc × 8 kpc area, where signatures of positive feedback have previously been found. These densities are comparable to those in other populations of massive, dusty star-forming galaxies in this redshift range, suggesting that the jet does not currently enhance the efficiency with which stars form from the gas. This is consistent with expectations from simulations, whereby radio jets may facilitate the onset of star formation in galaxies without boosting its efficiency over longer timescales, in particular after the jet has broken out of the interstellar medium, as is the case in 4C 41.17.
Preclinical evidence suggests statins may have anti-tumor properties. Large observational studies are also consistent with improved survival and cancer-specific outcomes among cancer patients on ...statins. We sought to evaluate the randomized controlled trials of statins in addition to usual anti-cancer therapy.
A systematic search of MEDLINE, Embase, CINAHL, Cochrane Library, Web of Science, Papers First and Clinicaltrials.gov was performed from inception through to July 4, 2017 to identify randomized clinical trials that investigated statin therapy in cancer patients. Our primary outcome was overall survival and our secondary outcome was progression-free survival. We calculated summary hazard ratio's (HR) and 95% confidence intervals (CI) based on random-effects models using aggregate data. PROSPERO (CRD42017065503).
Ten studies with 1,881 individuals were included with 1,572 deaths and a median follow-up of 23 months. All trials included patients with advanced (stage 3 or higher) disease. There was minimal between-study statistical heterogeneity (I2 = 1.8%, for OS; I2 = 0%, for PFS). The pooled HR for overall survival in patients randomized to statins plus standard anti-cancer therapy versus standard therapy alone was 0.94 (95% CI, 0.85 to 1.04). In the 9 studies that reported progression-free survival (1,798 participants), the pooled HR for statin plus standard therapy versus standard therapy alone was 0.97 (95% CI, 0.87 to 1.07).
In patients with advanced cancer and a prognosis <2 years, the addition of statins to standard anti-cancer therapy does not appear to improve overall survival or progression-free survival. Future research should assess if cancer patients with better prognosis benefit from longer-term statin therapy.
Aims
The aim of this study is to determine the ability of two bioactive compounds, namely, eugenol and linalool, purified from leaves of Ocimum tenuiflorum for eradication of biofilm produced by ...Pseudomonas aeruginosa.
Methods and Results
The phytoextract of O. tenuiflorum (KT), a common ethno‐botanical plant of India, was purified through high‐performance liquid chromatography and was analysed using ultraviolet (UV) spectroscopy and gas chromatography–mass spectrometry (GC‐MS). Eugenol and linalool were found to be the most active amongst all phytocompounds present in phytoextract and showed a significant reduction in the viability of sessile cells of P. aeruginosa and the minimum revival after withdrawal of phyto‐challenge. They could bring about notable reduction in the protein and carbohydrate content of exopolysaccharide of biofilm. Eugenol and linalool could affect the synthesis of quorum sensing (QS) proteins like LasA and LasB as well as virulence factors such as pyocyanin, and rhamnolipids, which seriously hamper the formation of biofilm. The biofilm framework was extremely affected by the phytocompounds through the reduction of protein and carbohydrate content of extracellular polymeric substance (EPS). Another interesting found out was that they brought about maximum inhibition to the genomic DNA and RNA content. The studies were supported by in silico interaction between eugenol and linalool with the QS proteins. The antibiofilm efficacies of eugenol, linalool and phytoextract (KT) were further confirmed by microscopic studies with scanning electron microscopy (SEM), atomic force microscopy and fluorescence confocal microscopy microscopic studies.
Conclusions
The phytocompounds are proved to be more effective than conventional antibiotics in inhibiting the biofilm forming sessile cells and can be used as a replacement for antibiotic.
Significance and Impact of the Study
Pure eugenol extracted from common basil leaves can be used as a safe substitute for common antibiotic for treatment of chronic infections caused by P. aeruginosa. It will be cost effective, devoid of notable side effects and will not generate antibiotic resistance in host body.
Metal contamination in a river has often been assessed based on total metal ion concentrations without relating them with the amount of suspended solids. This approach masks lot of important dynamics ...of metal ions in water. This is first time in India, a study has been undertaken to present how the level of metal ions in river water is influenced by suspended solids in response to spatial and seasonal conditions in Hugli estuary, India and to focus necessity of harmonizing science and policy. This study presented extent of metal pollution and distribution pattern over the stations, seasons, tides and depth. Major fraction of metal ions is associated with suspended sediments and discharges into the largest alluvial fan, Bengal fan, in the world. Enrichment factors indicated that major source of metal contamination is large influx of sediment due to strong natural activities and moderate anthropogenic activities over the years strong seasonal change, variable tidal energy level and irregular estuarine geometry play crucial role in maintaining metal concentrations in water column. Findings of this study would help to refine existing monitoring practice and to understand its importance in water quality management.
Energetic feedback by active galactic nuclei (AGNs) plays an important evolutionary role in the regulation of star formation on galactic scales. However, the effects of this feedback as a function of ...redshift and galaxy properties such as mass, environment, and cold gas content remain poorly understood. The broad frequency coverage (1 to 116 GHz), high sensitivity (up to ten times higher than the Karl G. Jansky Very Large Array), and superb angular resolution (maximum baselines of at least a few hundred kilometers) of the proposed next-generation Very Large Array (ngVLA) are uniquely poised to revolutionize our understanding of AGNs and their role in galaxy evolution. Here, we provide an overview of the science related to AGN feedback that will be possible in the ngVLA era and present new continuum ngVLA imaging simulations of resolved radio jets spanning a wide range of intrinsic extents. We also consider key computational challenges and discuss exciting opportunities for multiwavelength synergy with other next-generation instruments, such as the Square Kilometer Array and the James Webb Space Telescope. The unique combination of high-resolution, large collecting area, and wide frequency range will enable significant advancements in our understanding of the effects of jet-driven feedback on sub-galactic scales, particularly for sources with extents of a few parsec to a few kiloparsec, such as young and/or lower-power radio AGNs, AGNs hosted by low-mass galaxies, radio jets that are interacting strongly with the interstellar medium of the host galaxy, and AGNs at high redshift.
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