Effect of preheating on the nonlinear evolution of the ablative Rayleigh-Taylor instability

We calculated the linear and nonlinear growth rates of whistler‐mode chorus waves with relativistic treatment across different wave frequencies and investigated their dependence on the associated parameters, including background magnetic field strength, cold electron density, and energetic electron temperature. The linear and nonlinear growth rates, with respect to any of the three parameters in the range investigated, are confirmed to often exhibit a peak, at least, in the lower band (i.e., <0.5 fce, electron cyclotron frequency). For a given energetic electron temperature between 0.5 and 500 keV, both linear and nonlinear growth rates at low frequencies can be positive in a specific range of background magnetic field strength and cold electron density, with an optimum growth rate occurring when either parameter is fixed. However, as the electron temperature increases within this range, linear damping becomes more pronounced, resulting in a suppression of linear growth at high frequencies. On the other hand, as the strength of the magnetic field increases, a higher energetic electron temperature is required to sustain wave growth. Notably, nonlinear growth can still occur even when the linear growth rate is negative as previous studies have demonstrated. Parameters leading to such conditions are also demonstrated. Comparisons with previous chorus wave observations confirm the dependence on the parameters and explain the existence of an optimum wave growth condition and overlapping parameter ranges for both linear and nonlinear wave growth.

Kinetic study on light-limited batch cultivation of photosynthetic cells

Small Renal Masses Managed With Active Surveillance: Predictors of Tumor Growth Rate After Long-Term Follow-Up

Functions with a linear (p = 1) local growth rate from their argmin sets have been referred to as having weak sharp minima. A function with linear growth rate from its argmin set shares many nice properties with the polyhedral functions and so does a function with quadratic growth rate with strongly convex functions. Many classical results regarding functions with isolated minimizers of order p have been extended to the cases with nonunique minimizers, especially since the introduction and the extensive study of the concept of weak sharp minima by M. C. Ferris and J. Burke. The upper Holder continuity is most suitable for the study of a subdifferential or a inverse subdifferential multifunction. same assertion can be made to the solution multifunction of a parametric mathematical programming problem.

The transport, flow shear, and linear growth rates of microturbulence are studied for a JET plasma with high central q in which an internal transport barrier (ITB) forms and grows to a large radius. The linear microturbulence growth rates of the fastest growing (most unstable) toroidal modes with high toroidal mode number are calculated using the GS2 and FULL gyrokinetic codes. These linear growth rates, γlin, are large, but the flow-shearing rates, γE×B (dominated by the toroidal rotation contribution), are also comparably large when and where the ITB exists.

A ring‐like proton velocity distribution with ∂fp(v⊥)/∂v⊥>0 and which is sufficiently anisotropic can excite two distinct types of growing modes in the inner magnetosphere: ion Bernstein instabilities with multiple ion cyclotron harmonics and quasi‐perpendicular propagation and an Alfvén‐cyclotron instability at frequencies below the proton cyclotron frequency and quasi‐parallel propagation. Recent particle‐in‐cell simulations have demonstrated that even if the maximum linear growth rate of the latter instability is smaller than the corresponding growth of the former instability, the saturation levels of the fluctuating magnetic fields can be greater for the Alfvén‐cyclotron instability than for the ion Bernstein instabilities. In this study, linear dispersion theory and two‐dimensional particle‐in‐cell simulations are used to examine scalings of the linear growth rate and saturation level of the two types of growing modes as functions of the temperature anisotropy T⊥/T|| for a general ring‐like proton distribution with a fixed ring speed of 2vA, where vA is the Alfvén speed. For the proton distribution parameters chosen, the maximum linear theory growth rate of the Alfvén‐cyclotron waves is smaller than that of the fastest‐growing Bernstein mode for the wide range of anisotropies (1≤T⊥/T||≤7) considered here. Yet the corresponding particle‐in‐cell simulations yield a higher saturation level of the fluctuating magnetic fields for the Alfvén‐cyclotron instability than for the Bernstein modes as long as . Since fast magnetosonic waves with ion Bernstein instability properties observed in the magnetosphere are often not accompanied by electromagnetic ion cyclotron waves, the results of the present study indicate that the ring‐like proton distributions responsible for the excitation of these fast magnetosonic waves should not be very anisotropic.

Human scalp hair is a validated bio-substrate for monitoring various exposures in childhood including contextual stressors, environmental toxins, prescription or non-prescription drugs. Linear hair growth rates (HGR) are required to accurately interpret hair biomarker concentrations. We measured HGR in a prospective cohort of preschool children (N = 266) aged 9-72 months and assessed demographic factors, anthropometrics, and hair protein content (HPC). We examined HGR differences by age, sex, race, height, hair pigment, and season, and used univariable and multivariable linear regression models to identify HGR-related factors. Infants below 1 year (288 ± 61 μm/day) had slower HGR than children aged 2-5 years (p = 0.0073). Dark-haired children (352 ± 52 μm/day) had higher HGR than light-haired children (325 ± 50 μm/day; p = 0.0019). Asian subjects had the highest HGR overall (p = 0.016). Younger children had higher HPC (p = 0.0014) and their HPC-adjusted HGRs were slower than older children (p = 0.0073). Age, height, hair pigmentation, and HPC were related to HGR in multivariable regression models. We identified age, height, hair pigment, and hair protein concentration as significant determinants of linear HGRs. These findings help explain the known hair biomarker differences between children and adults and aid accurate interpretation of hair biomarker results in preschool children. Discovery of hair biomarkers in the past few decades has transformed scientific disciplines like toxicology, pharmacology, epidemiology, forensics, healthcare, and developmental psychology. Identifying determinants of hair growth in children is essential for accurate interpretation of hair biomarker results in pediatric clinical studies. Childhood hair growth rates define the time-periods of biomarker incorporation into growing hair, essential for interpreting the biomarkers associated with environmental exposures and the mind-brain-body connectome. Our study describes age-, sex-, and height-based distributions of linear hair growth rates and provides determinants of linear hair growth rates in a large population of children. Age, height, hair pigmentation, and hair protein content are determinants of hair growth rates and should be accounted for in child hair biomarkers studies. Our findings on hair protein content and linear hair growth rates may provide physiological explanations for differences in hair growth rates and biomarkers in preschool children as compared to adults.

An ion acoustic wave in a current carrying plasma is studied by a microwave scattering method. A technique for incoherent scattering of electromagnetic wave of fi=35 GHz by ion acoustic waves of f=20∼70 kHz is described. A dispersion relation and the intensity distribution in k-space of the ion acoustic wave is determined from the angular distribution of the scattered wave. A spatial evolution of the ion acoustic waves along the tube axis is also observed. The observed spatial growth rates are compared with calculated values which take account of both linear and nonlinear growth rates. The linear growth rate thus obtained agrees well with the theoretical value derived for a current carrying plasma, and the value of the nonlinear growth rate is also reasonable when the nonlinear effect is assumed to be due to the ion-trapping.

BackgroundInvestigating the growth characteristics of lung adenocarcinoma manifesting as ground-glass nodules (gLUAD) and assessing its invasiveness based on these features are crucial for optimizing follow-up and intervention strategies. This study aimed to systematically analyze the growth dynamics of gLUAD and compare the value of different growth evaluation methods in predicting gLUAD invasiveness.MethodsA total of 564 participants with 625 gLUAD were retrospectively enrolled from the First and Fourth Medical Centers of the Chinese PLA General Hospital between January 2018 and December 2022. gLUAD was pathologically classified into two categories: adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC). Growth evaluation was conducted using four definitions (size growth, volume growth, mass growth, and stage shift) and two growth models (linear and exponential models). These methods were further evaluated in terms of their effectiveness in assessing gLUAD invasiveness.ResultsThe median follow-up period of gLUAD in this study was 1,050 days. The median doubling times for total/solid size, volume, and mass of gLUAD were >3,650/3,042 days, 1,460/1,014 days, and 1,521/1,014 days, respectively. For AIS/MIA, all doubling times exceeded 3,650 days, whereas for IAC, they were 3,318/2,147 days, 1,141/777 days, and 1,074/760 days, respectively. The R2 and root mean squared error (RMSE) values for the linear and exponential growth models in fitting total/solid size, volume, and mass were 0.98/0.95 vs. 0.98/0.95, 0.98/0.90 vs. 0.98/0.93, and 0.95/0.90 vs. 0.98/0.92 for R2, while they were 0.53/0.92 vs. 0.51/0.94, 169.80/100.00 vs. 143.87/106.81, and 116.12/101.24 vs. 72.81/108.99 for RMSE, respectively. The median growth times for size growth, volume growth, mass growth, and stage shift of gLUAD were 1,273, 750, 792, and 1,672 days, respectively. Compared to AIS/MIA, IAC exhibited significantly higher growth rates (all P values <0.001). For invasiveness assessment, the linear growth rates (LGRs) outperformed the exponential growth rates (EGRs) in discriminative value (all P values <0.05). Among the growth evaluation methods, the LGR of total mass demonstrated the highest discriminative ability for pathological subtypes of gLUAD, with an area under the curve (AUC) of 0.83. At an optimal cutoff of 16.80 mg/year, the accuracy, sensitivity, and specificity for distinguishing gLUAD with different invasiveness were 0.78, 0.77, and 0.79, respectively.ConclusionsgLUAD exhibited an indolent growth pattern, with significant differences in growth trends between AIS/MIA and IAC. Both the linear and exponential growth models showed similar fitting performance for gLUAD growth, while the linear growth model provided a more reliable assessment of invasiveness. The LGR of total mass offered superior differentiation between AIS/MIA and IAC and may serve as a valuable auxiliary indicator for assessing gLUAD invasiveness.

Kinetics of calcite growth: surface processes and relationships to macroscopic rate laws

Thin current sheets, with thicknesses of the order of a few ion gyroradii, are believed to exist quite commonly at the Earth's magnetopause as well as in the magnetotail current sheet just prior to substorm onset. Analytical theory predicts that sheets of this kind can become the locus of an ion‐tearing instability. We use a modified hybrid simulation code that treats the ions fully kinetically and the electrons as a fluid with a model for the full pressure tensor to study the ion tearing mode development in one‐dimensional current sheets of various thicknesses, with varying initial electron to ion temperature ratios. Further, we investigate the electron anisotropy dependence of the ion tearing mode growth rate and compare the growth rates found in the numerical simulations to linear growth rates for the pure ion‐tearing instability derived from analytic theory. Estimates of the numerical accuracy of the simulations and of possible electron distribution functions resulting in the modeled anisotropies are also presented.

In laser-driven inertial confinement fusion (ICF) specifically with high laser intensities, energetic (hot) electrons (HEs) can be generated via laser-plasma instabilities. HEs can significantly impact the target performance by modifying the implosion hydrodynamics. In this paper, the effects of moderate-energy (about 20 to 40 keV) HEs on the evolution of two-dimensional single-mode ablative Rayleigh–Taylor instability (ARTI) are studied through numerical simulations with a multigroup diffusion model in which the HE population is treated as a high-energy group launched from the boundary. With HEs present, it is found that ARTI linear growth rates are reduced even though the acceleration of the implosion shell is enhanced by HEs. The reduction in the linear growth rate is owing to the increase in the ablation velocity and the density scale length, and this stabilization effect is greater in the shorter-wavelength modes and/or higher-energy HE cases. The ARTI linear growth does not get mitigated monotonically as the HE number density increases for a given fixed HE kinetic energy. The HE number density minimizing the ARTI growth rate is found, likely due to the competition of the stabilizing and destabilizing hydrodynamic-parameter variations caused by HEs.

As a result of recent comprehensive laboratory and field studies, many details have been clarified concerning atmospheric ice crystal habits below −20°C as a function of temperature, ice supersaturation, air pressure, and growth history. A predominance of complex shapes has been revealed that is not reflected in most models, with symmetric shapes often incorrectly emphasized. From the laboratory study, linear (maximum dimension), projected area, and volume growth rates of complex and simple habits have been measured under simulated atmospheric conditions for temperatures from −20° to −70°C. Presently, only a few in situ cases of measured ice crystal growth rates are available for comparison with laboratory results. Observations from the Interaction of Aerosol and Cold Clouds (INTACC) field study of a well-characterized wave cloud at −24°C are compared with the laboratory results using a simple method of habit averaging to derive a range of expected growth rates. Laboratory results are also compared with recently reported wave cloud results from the Ice in Clouds Experiment–Layer Clouds (ICE-L) study between −20° and −32°C, in addition to a much colder wave cloud at −65°C. Considerable agreement is observed in these cases, confirming the reliability of the laboratory measurements. This is the first of two companion papers that compare laboratory growth rates and characteristics with in situ measurements, confirming that the laboratory results effectively provide a predictive capability for cloud particle and particle ensemble growth.

Sub-weekly coral linear extension measurements in a coral reef

The linear growth rate is an essential parameter to describe and simulate the crystal growth processes of solid materials. Concerning the calcite mineral, indirect methods (by depletion of calcium concentration) and direct methods (ex. using microscopic measurements) have been reported in the literature. Here, homogeneous (solution−solution) or heterogeneous (solution−solid) systems are systematically considered. Conversely, the estimation of linear growth rate of calcite for the triphasic gas−liquid−solid systems under high gas pressure and temperature has not been reported in the literature to the best of our knowledge. In the present study, we propose a new method to estimate the linear growth initial rate of submicrometric calcite produced in a triphasic gas−liquid−solid system under high gas pressure (55 and 90 bar) and moderated to high temperature (30 and 90 °C) by using Rietveld refinements of X-ray diffraction (XRD) patterns. These Rietveld refinements allowed the estimation on the variation of the coherent domain average size r (nm) with reaction time t (s). Then, a kinetic pseudo-second-order model was satisfactory used to fit the experimental−calculated data and determine the linear growth initial rate of submicrometric calcite. The results showed that the values of linear growth rate of calcite were equivalents for both systems, i.e., 0.14 nm/s at 30 °C and 55 bar and 0.12 nm/s at 90 °C and 90 bar. However, the average size of calcite crystals, here expressed as a maximum of coherent domain average size, was clearly higher at 90 °C and 90 bar (174 nm) than at 30 °C and 55 bar (63 nm). The main advantage for this method is the possibility to estimate the linear growth rate of crystalline fine particles (>40 nm) growing in triphasic gas−liquid−solid systems. Here, it is considered that depressurization of cell reaction has insignificant physicochemical effect on the solid precipitates; obviously, this is not the case for the interacting solutions.