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Clipping-and-burning alters carbon and nitrogen cycling through bacterial fixation pathways in the key Chinese karst region
No full texthttp://dx.doi.org/10.13039/100015809 Ministry of Natural Resources of the People's Republic of Chinahttp://dx.doi.org/10.13039/501100001809 National Natural Science Foundation of Chin
Special measures of smoothness for approximation by sampling operators in L p ( R d )
No full texthttp://dx.doi.org/10.13039/501100001659 German Research Foundatio
Histidine-rich coiled-coils promote zinc-dependent self-assembly and curing of porous mussel glues
No full textGouvernement du Canada | Natural Sciences and Engineering Research Council of Canada https://doi.org/10.13039/501100000038Canada Research Chairs https://doi.org/10.13039/501100001804Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung https://doi.org/10.13039/501100001711Deutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659Fonds De La Recherche Scientifique - FNRS https://doi.org/10.13039/50110000266
Impacting spheres: from liquid drops to elastic beads
No full textA liquid drop impacting a non-wetting rigid substrate spreads, retracts and rebounds, while an elastic sphere deforms slightly and bounces off. This work bridges these two limits and offers a framework for liquid-to-elastic transitions.A liquid drop impacting a non-wetting rigid substrate spreads laterally, then retracts, and finally jumps off again. An elastic solid, by contrast, undergoes a slight deformation, contacts briefly, and bounces. The impact force on the substrate – crucial for engineering and natural processes – is classically described by Wagner's (liquids) and Hertz's (solids) theories. This work bridges these limits by considering a generic viscoelastic medium. Using direct numerical simulations, we study a viscoelastic sphere impacting a rigid, non-contacting surface and quantify how the elasticity number (El, dimensionless elastic modulus) and the Weissenberg number (Wi, dimensionless relaxation time) dictate the impact force. We recover the Newtonian liquid response as either El → 0 or Wi → 0, and obtain elastic-solid behavior in the limit Wi → ∞ and El ≫ 1. In this elastic-memory limit, three regimes emerge – capillary-dominated, Wagner scaling, and Hertz scaling – with a smooth transition from the Wagner to the Hertz regime. Sweeping Wi from 0 to ∞ reveals a continuous shift from materials with no memory to materials with permanent memory of deformation, providing an alternate, controlled route from liquid drops to elastic beads. The study unifies liquid and solid impact processes and offers a general framework for the liquid-to-elastic transition relevant across systems and applications.A liquid drop impacting a non-wetting rigid substrate spreads, retracts and rebounds, while an elastic sphere deforms slightly and bounces off. This work bridges these two limits and offers a framework for liquid-to-elastic transitions.A liquid drop impacting a non-wetting rigid substrate spreads laterally, then retracts, and finally jumps off again. An elastic solid, by contrast, undergoes a slight deformation, contacts briefly, and bounces. The impact force on the substrate – crucial for engineering and natural processes – is classically described by Wagner's (liquids) and Hertz's (solids) theories. This work bridges these limits by considering a generic viscoelastic medium. Using direct numerical simulations, we study a viscoelastic sphere impacting a rigid, non-contacting surface and quantify how the elasticity number (El, dimensionless elastic modulus) and the Weissenberg number (Wi, dimensionless relaxation time) dictate the impact force. We recover the Newtonian liquid response as either El → 0 or Wi → 0, and obtain elastic-solid behavior in the limit Wi → ∞ and El ≫ 1. In this elastic-memory limit, three regimes emerge – capillary-dominated, Wagner scaling, and Hertz scaling – with a smooth transition from the Wagner to the Hertz regime. Sweeping Wi from 0 to ∞ reveals a continuous shift from materials with no memory to materials with permanent memory of deformation, providing an alternate, controlled route from liquid drops to elastic beads. The study unifies liquid and solid impact processes and offers a general framework for the liquid-to-elastic transition relevant across systems and applications.Durham University https://doi.org/10.13039/50110000131
Multiple short-term cycles in Kepler star KIC 6876668
No full textContext. Solar and stellar magnetic activity may have similar properties, which can be used to understand the stellar magnetic evolution. Aims. This paper examines the multiple short-term cycles in the total irradiance of the Sun and in the light curve of a Kepler star, KIC 6876668. Methods. We study the light curve variations of KIC 6876668, which exhibits a rotation period of 5−6 d. In order to detect cyclic patterns across rotational and Rieger timescales, we used wavelet and Lomb-Scargle (LS) methodologies. Results. We found that the light curve of the star exhibits periodicities at ∼47, 59 and 72 d, which are fully consistent with the Rieger period range. Through LS and wavelet analysis, we also found variations in the total irradiance of the Sun as a star in cycle 23 of ∼185, 240, and 380 d. The ratios of stellar and solar cyclic periods over their rotation periods revealed striking similarities of ∼8, ∼10, and 12−15. The observed cycles are interpreted as the spherical harmonics of magnetic Rossby waves in dynamo layers of the star and the Sun. The corresponding magnetic field strengths are estimated as 40 kG and 10 kG in the stellar and solar interiors, respectively. The relationship observed between the Rieger cycle and the rotation period of a young star suggests that the processes in its inner layers driving stellar cycles resemble those found in the Sun. Conclusions. These results provide an insight into the internal magnetic processes in a Sun-like star, KIC 6876668, where a short cycle and a strong magnetic field indicate stronger activity. Sun-like stars as well as other stars may show similar variations in magnetic activity to the Sun. Therefore, the cycles can be used to extract plasma parameters in their interior. Our analysis shows that the ratio of the rotation angular frequency and the estimated magnetic field strength might stay constant (Ω/ B = constant) throughout stellar evolution
The vignette study: examining the effects of multiple variables in foreign-language teaching and learning
No full textAbstract This article introduces the vignette study as a research method in foreign-language education that can be used to examine the effects and interaction of multiple variables. A vignette study presents hypothetical scenarios (i.e., vignettes) to its participants (i.e., L2 learners, L2 teachers) to investigate their self-reported attitudes, decisions, or reactions regarding these vignettes. A vignette set systematically varies attributes in its vignettes (e.g., L2 feedback type). The vignette study is thus able to identify the causal effect of these attributes on the participants’ attitudes, decisions, or reactions (e.g., learner motivation). The vignette study offers several benefits to L2 research, such as flexible research questions, analysis of multiple variables, compatibility with quantitative and qualitative assessments, and research economy. The vignette study is a valuable, but underused method to investigate complex causal interactions in foreign-language education. To illustrate the potential of the vignette study for L2 research, the article presents an exemplary vignette study with L1-German L2-English students (grade 5-9, secondary school). The vignette study examined the effect of online vs. onsite teaching (IV) on the students’ foreign-language enjoyment (DV) in the L2 English classroom and showed that their enjoyment was lowered by online teaching in the study sample (i.e., descriptive, but non-significant result)
Pelacarsen and lipoprotein(a) apheresis in secondary prevention: the Lp(a)FRONTIERS APHERESIS trial
No full textAbstract Background and Aims Lipoprotein apheresis (LA) is the only approved treatment for patients with elevated lipoprotein(a) [Lp(a)]. The Lp(a)FRONTIERS APHERESIS trial investigated whether pelacarsen reduces the need for LA in patients from Germany with elevated Lp(a) and established cardiovascular disease (CVD). Methods Adult patients with Lp(a) levels >60 mg/dl who had undergone ≥35 LA sessions in the prior year were randomized to receive pelacarsen 80 mg or placebo every 4 weeks for 52 weeks. Weekly LA sessions were performed if the Lp(a) measurement from the prior visit was >60 mg/dL. The primary endpoint was the rate of performed LA sessions normalized to the weekly LA schedule (the number of actual LA sessions divided by the number of planned LA sessions during the 52-week period). Secondary endpoints were time to LA avoidance (for ≥24 consecutive weeks) and total LA avoidance from week 12 to week 52. Results Fifty-one patients were randomized (mean age 61.7 years, mean Lp(a) at baseline 85.4 mg/dL, and mean 44.0 LA sessions in the past 12 months), with 25 of 26 (96.2%) in the pelacarsen arm and 23 of 25 (92.0%) in the placebo arm completing the study. Baseline characteristics were generally balanced between treatment arms. Pelacarsen reduced the mean rates of LA (0.16 vs 0.93 in placebo, odds ratio 0.006, 95% confidence interval [CI] 0.003, 0.013; P < .0001) and substantially increased the hazard of achieving LA avoidance (hazard ratio: 88.3; P = .0014; median time to achieve LA avoidance: 6.1 weeks) and total LA avoidance (odds ratio: 163.2; P = .0005). The placebo-adjusted Lp(a) change from baseline at week 52 was −72% (95% CI: −79%, −61%; P < .0001). Treatment emergent adverse events were similar between arms, except for mostly mild injection site erythema (pelacarsen 38.5%; placebo 0%). Conclusions Pelacarsen is a highly effective and well-tolerated Lp(a)-targeted therapy that substantially reduces the need for LA in patients with elevated Lp(a) and established CVD. ClinicalTrials.gov, identifier NCT05305664
