Tardigrades are remarkable for their ability to survive harsh stress conditions as diverse as extreme temperature and desiccation. The molecular mechanisms that confer this unusual resistance to ...physical stress remain unknown. Recently, tardigrade‐unique intrinsically disordered proteins have been shown to play an essential role in tardigrade anhydrobiosis. Here, we characterize the conformational and physical behaviour of CAHS‐8 from Hypsibius exemplaris. NMR spectroscopy reveals that the protein comprises an extended central helical domain flanked by disordered termini. Upon concentration, the protein is shown to successively form oligomers, long fibres, and finally gels constituted of fibres in a strongly temperature‐dependent manner. The helical domain forms the core of the fibrillar structure, with the disordered termini remaining highly dynamic within the gel. Soluble proteins can be encapsulated within cavities in the gel, maintaining their functional form. The ability to reversibly form fibrous gels may be associated with the enhanced protective properties of these proteins.
The conformational behaviour of an intrinsically disordered protein responsible for protecting tardigrades against extreme stress has been characterized. The protein assembles into fibres and fibrillar gels as a function of temperature and concentration. The disordered tails remain flexible within the gel cavities, which can encapsulate client proteins in their native state.
The plasticity and growth of plant cell walls (CWs) remain poorly understood at the molecular level. In this work, we used atomic force microscopy (AFM) to observe elastic responses of the root ...transition zone of 4‐day‐old Arabidopsis thaliana wild‐type and almt1‐mutant seedlings grown under Fe or Al stresses. Elastic parameters were deduced from force‐distance curve measurements using the trimechanic‐3PCS framework. The presence of single metal species Fe2+ or Al3+ at 10 µM exerts no noticeable effect on the root growth compared with the control conditions. On the contrary, a mix of both the metal ions produced a strong root‐extension arrest concomitant with significant increase of CW stiffness. Raising the concentration of either Fe2+ or Al3+ to 20 µM, no root‐extension arrest was observed; nevertheless, an increase in root stiffness occurred. In the presence of both the metal ions at 10 µM, root‐extension arrest was not observed in the almt1 mutant, which substantially abolishes the ability to exude malate. Our results indicate that the combination of Fe2+ and Al3+ with exuded malate is crucial for both CW stiffening and root‐extension arrest. However, stiffness increase induced by single Fe2+ or Al3+ is not sufficient for arresting root growth in our experimental conditions.
Summary statement
We investigate the change in stiffness of the external primary cell wall of living Arabidopsis thaliana seedlings in the presence of metallic stress using atomic force microscopy. Results reveal for the first time the uncoupling between mechanical response (CW stiffening) and root extension arrest.
We explore the dependence of the incidence of moderate-luminosity (L0.5−8 keV = 1041.9−43.7 erg s-1) active galactic nuclei (AGNs) and the distribution of their accretion rates on host color at 0.5 ...<z < 2.5. Based on the deepest X-ray and UV-to-far-infrared data in the two The Great Observatories Origins Deep Survey (GOODS) fields, we identify 221 AGNs within a mass-complete parent galaxy sample down to M∗ > 1010 M⊙. We use extinction-corrected rest-frame U−V colors to divide both AGN hosts and non-AGN galaxies into red sequence (red), green valley (green), and blue cloud (blue) populations. We find that the fraction of galaxies hosting an AGN at fixed X-ray luminosity increases with stellar mass and redshift for all the three galaxy populations, independent of their colors. However, both the AGN fraction at fixed stellar mass and its evolution with redshift are clearly dependent on host colors. Most notably, red galaxies have the lowest AGN fraction (~5%) at z ~ 1 yet with most rapid evolution with redshift, increasing by a factor of ~5 (24%) at z ~ 2. Green galaxies exhibit the highest AGN fraction across all redshifts, which is most pronounced at z ~ 2 with more than half of them hosting an AGN at M∗ > 1010.6 M⊙. Together with the high AGN fraction in red galaxies at z ~ 2, this indicates that (X-ray) AGNs could be important in both transforming (quenching) star-forming galaxies into quiescent ones and subsequently maintaining their quiescence at high redshift. Furthermore, consistent with previous studies at lower redshifts, we show that the probability of hosting an AGN for the total galaxy population can be characterized by a universal Eddington ratio (as approximated by LX/M∗) distribution (p(λEdd) ~ λEdd-0.4), which is independent on host mass. Yet consistent with their different AGN fractions, galaxies with different colors appear to also have different p(λEdd) with red galaxies exhibiting more rapid redshift evolution compared with that for green and blue galaxies. Evidence for a steeper power-law distribution of p(λEdd) in red galaxies (p(λEdd) ~ λEdd-0.6) is also presented, though larger samples are needed to confirm. These results suggest that the AGN accretion or the growth of supermassive black holes is related to their host properties, and may also influence their hosts in a different mode dependent on the host color.
Land application of biosolids is one potential source of pharmaceuticals and personal care products (PPCPs) into agricultural soils. Degradation is an important natural attenuation pathway that ...affects the fate and transport of PPCPs in the soil system and biosolids application could alter the process. The present study assessed the effect of individual and mixture compound environments on the biodegradation rate and half-life of three non-steroidal anti-inflammatory drugs (NSAIDs), naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF), in a loamy sand textured agricultural soil receiving an alkaline treated biosolid (ATB) amendment. A prolonged half-life of the target NSAIDs was determined for sterile soils and shorter half-lives in unsterile soils, indicating the loss of target compounds in all treatments was mainly attributed to biodegradation and followed first-order kinetics. IBF and NPX showed low to moderate persistence in soil and ATB amended soil, with half-lives ranging from 4.9 to 14.8 days, while KTF appeared to be highly persistent with an average half-life of 33 days. The order in which the target NSAIDs disappeared in both soil and ATB amended soil was: IBF > NPX > KTF, for both individual and mixture compound treatments. Soils that received the ATB amendment demonstrated inhibited degradation of NPX in all treatments, as well as IBF and KTF in individual compound treatment over the 14-day incubation study. We also observed an inhibition effect from the ATB amendment in sterile soil treatments. In mixture compound treatments, IBF degradation was inhibited in both soil and ATB amended soil. The degradation rate of KTF in mixture compound environment in soil was lower, while the opposite effects were observed in ATB amended soils. For NPX, the degradation was enhanced in mixture compound environment in ATB amended soil, while the same degradation rate of NPX was calculated in soil.
Display omitted
•Degradation of three NSAIDs was evaluated as individual vs mixture compounds in soil with and without biosolids.•Biodegradation was a significant pathway for NSAID loss in soil.•Biodegradation accounted for 20 to 50% of losses for naproxen, ibuprofen, and ketoprofen•Biosolids addition inhibited degradation kinetics of NSAIDs in soil•NSAID loss from soil followed first-order kinetics
Bedaquiline treatment significantly improves multidrug-resistant tuberculosis (MDR-TB) patient treatment outcomes. However, safety and efficacy data are lacking for bedaquiline used with background ...regimens to treat Chinese TB patients. Here, we describe our initial clinical experience for bedaquiline treatment of a large multicentre cohort of MDR-TB and extensively drug-resistant tuberculosis (XDR-TB) patients in China.
Patients (177) received 24-week bedaquiline treatment combined with personalized anti-TB drug background regimens. As primary efficacy endpoints, times to initial sputum culture conversion were measured.
Of 177 MDR-TB patients completing the 24-week treatment course, sputum culture conversion occurred for 151/177 (85.3%), while 26 had unfavourable outcomes, including 3/177 (1.7%) deaths and 23/177 (13.0%) non-responders at treatment completion. The median time to sputum culture conversion was 4 (interquartile range 2–8) weeks. Conversion rates were 33/39 (84.6%, 95% confidence interval (CI) 73.3–95.9) for MDR-TB patients, 47/56 (83.9%, 95% CI 74.3–93.6) for pre-XDR-TB patients and 71/82 (86.6%, 95% CI 79.2–94.0) for XDR-TB patients. Multivariate analysis demonstrated that patients with low body mass index (odds ratio 7.356; 95% CI 2.652–20.401) were at significantly high risk of unfavourable outcomes, with serious adverse events noted in 15 (8.5%) patients, including six with corrected QT interval (QTc) prolongation times (>500 ms).
Bedaquiline, when included in background regimens for treatment of MDR-TB and XDR-TB patients in China, was safe and associated with a high rate of culture conversion.
In this paper, we continue our research on the numerical study of convergence to steady-state solutions for a new class of finite volume weighted essentially non-oscillatory (WENO) schemes in Zhu and ...Shu (J Comput Phys 349:80–96,
2017
), from tensor product meshes to triangular meshes. For the case of triangular meshes, this new class of finite volume WENO schemes was designed for time-dependent conservation laws in Zhu and Qiu (SIAM J Sci Comput 40(2):A903–A928,
2018
) for the third- and fourth-order versions. In this paper, we extend the design to a new fifth-order version in the same framework to keep the essentially non-oscillatory property near discontinuities. Similar to the case of tensor product meshes in Zhu and Shu (
2017
), by performing such spatial reconstruction procedures together with a TVD Runge–Kutta time discretization, these WENO schemes do not suffer from slight post-shock oscillations that are responsible for the phenomenon wherein the residues of classical WENO schemes hang at a truncation error level instead of converging to machine zero. The third-, fourth-, and fifth-order finite volume WENO schemes in this paper can suppress the slight post-shock oscillations and have their residues settling down to a tiny number close to machine zero in steady-state simulations in our extensive numerical experiments.
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used globally to treat and prevent illness. Biosolids change physico-chemical characteristics of soil and can affect the mobility of NSAIDs. ...A field-based lysimeter study evaluated the effect of three rates (0, 7, and 28 Mg ha−1) of alkaline treated biosolids (ATB) on the leaching potential of naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF) over 34 days in a sandy loam textured soil. Although all three NSAIDs in the lysimeter cells vertically migrated to deeper soil depths after spiking, the sum of all NPX, IBF, and KTF detected in the leachate samples from all treatments were only 0.03%, 0.02%, and 0.04% of the initial spiking mass to the surface soil, respectively. A mass balance analysis indicated a low accumulation of these compounds in the soil at the end of the study (Day 34) from all treatments with only 4.8%, 0.5%, and 0.7% of initial spiked NPX, IBF, and KTF, respectively. Application of ATB significantly increased soil pH and organic matter (OM) content of the soils but did not impact retention of the compounds in the soil profile. Overall, all three NSAIDs in the present study presented low mobility in the loamy sand textured agricultural soil.
Display omitted
•Biodegradation was the main mechanism of NSAIDs dissipation in the lysimeter cells.•Soil amended with biosolids did not impact the NSAIDs retention in the soil profile.•Naproxen, ibuprofen, and ketoprofen as parent compounds showed low mobility in the soil.•The low NSAIDs mass measured in leachate indicated a low risk to the environment.
Cry11Aa and Cyt1Aa are two pesticidal toxins produced by Bacillus thuringiensis subsp. israelensis. To improve our understanding of the nature of their oligomers in the toxic actions and synergistic ...effects, we performed the atomic force microscopy to probe the surfaces of their natively grown crystals, and used the L‐weight filter to enhance the structural features. By L‐weight filtering, molecular sizes of the Cry11Aa and Cyt1Aa monomers obtained are in excellent agreement with the three‐dimensional structures determined by x‐ray crystallography. Moreover, our results show that the layered feature of a structural element distinguishes the topographic characteristics of Cry11Aa and Cyt1Aa crystals, suggesting that the Cry11Aa toxin has a better chance than Cyt1Aa for multimerization and therefore cooperativeness of the toxic actions.
Phytoremediation is an in situ, cost-effective potential strategy for cleanup of sites contaminated with trace metals. Selection of plant materials is an important factor for successful field ...phytoremediation. A field experiment was carried out to evaluate the phytoextraction abilities of six high biomass plants (Vertiveria zizanioides, Dianthus chinensis, Rumex K-1 (Rumex upatientia x R. timschmicus), Rumex crispus, and two populations of Rumex acetosa) in comparison to metal hyperaccumulators (Viola baoshanensis, Sedum alfredii). The paddy fields used in the experiment were contaminated with Pb, Zn, and Cd. Our results indicated that V. baoshanensis accumulated 28 mg kg-¹ Cd and S. alfredii accumulated 6,279 mg kg-¹ Zn (dry weight) in shoots, with bioconcentration factors up to 4.8 and 6.3, respectively. The resulting total extractions of V. baoshanensis and S. alfredii were 0.17 kg ha-¹ for Cd and 32.7 kg ha-¹ for Zn, respectively, with one harvest without any treatment. The phytoextraction rates of V. baoshanensis and S. alfredii for Cd and Zn were 0.88 and 1.15%, respectively. Among the high biomass plants, R. crispus extracted Zn and Cd of 26.8 and 0.16 kg ha-¹, respectively, with one harvest without any treatment, so it could be a candidate species for phytoextraction of Cd and Zn from soil. No plants were proved to have the ability to phytoextract Pb with high efficiency.
Abstract
We present 97 new high-quality strong lensing candidates found in the final ∼350 deg
2
that complete the full ∼1350 deg
2
area of the Kilo-Degree Survey (KiDS). Together with our previous ...findings, the final list of high-quality candidates from KiDS sums up to 268 systems. The new sample is assembled using a new convolutional neural network (CNN) classifier applied to
r
-band (best-seeing) and
g
,
r
, and
i
color-composited images separately. This optimizes the complementarity of the morphology and color information on the identification of strong lensing candidates. We apply the new classifiers to a sample of luminous red galaxies (LRGs) and a sample of bright galaxies (BGs) and select candidates that received a high probability to be a lens from the CNN (
P
CNN
). In particular, setting
P
CNN
> 0.8 for the LRGs, the one-band CNN predicts 1213 candidates, while the three-band classifier yields 1299 candidates, with only ∼30% overlap. For the BGs, in order to minimize the false positives, we adopt a more conservative threshold,
P
CNN
> 0.9, for both CNN classifiers. This results in 3740 newly selected objects. The candidates from the two samples are visually inspected by seven coauthors to finally select 97 “high-quality” lens candidates which received mean scores larger than 6 (on a scale from 0 to 10). We finally discuss the effect of the seeing on the accuracy of CNN classification and possible avenues to increase the efficiency of multiband classifiers, in preparation of next-generation surveys from ground and space.
PDF
