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The short timescale of the solar flare reconnection process has long proved to be a puzzle. Recent studies suggest the importance of the formation of plasmoids in the reconnecting current sheet, with quantifying the aspect ratio of the width to length of the current sheet in terms of a negative power $ \alpha $ of the Lundquist number, that is, $ {S}^{-\alpha } $, being key to understanding the onset of plasmoids formation. In this paper, we make the first application of theoretical scalings for this aspect ratio to observed flares to evaluate how plasmoid formation may connect with observations. For three different flares that show plasmoids we find a range of $ \alpha $ values of $ \alpha =0.26 $ to $ 0.31 $. The values in this small range implies that plasmoids may be forming before the theoretically predicted critical aspect ratio ($ \alpha =1/3 $) has been reached, potentially presenting a challenge for the theoretical models.
Digital image correlation (DIC) techniques were used to evaluate strain distributions along tensile gage lengths immediately after yielding of a medium manganese steel (7 wt% Mn) in samples cold rolled in the range of 1–6 pct. With an increase in cold work, DIC confirmed that the yielding behavior transitioned from nucleation and propagation of a single localized deformation zone (Lüders band) to uniform deformation, that is, no evidence of strain localization. At intermediate amounts of cold work, a unique yielding behavior was evident where the initially-low positive strain hardening rate increased with tensile strain until conventional strain hardening (i.e., decrease in strain hardening rate with strain). The intermediate yielding behavior was associated with the development of multiple non‑propagating regions of strain localization, an observation not previously evident without the use of DIC.
The distribution of human leukocyte antigens in the population assists in matching solid organ donors and recipients when the typing methods used do not provide sufficiently precise information. This is made possible by linkage disequilibrium (LD), where alleles co-occur more often than random chance would suggest. There is a trade-off between the high bias and low variance of a broad sample from the population and the low bias but high variance of a focused sample. Some of this trade-off could be alleviated if sub-populations shared LD despite having different allele frequencies. These experiments show that Bayesian estimation can balance bias and variance by tuning the effective sample size of the reference panel, but the LD as represented by an additive or multiplicative copula is not shared.
Hydrogen sulfide (H2S, “sulfide”) is a naturally occurring component of the marine sediment. Eutrophication of coastal waters, however, can lead to an excess of sulfide production that can prove toxic to seagrasses. We used stable sulfur isotope ratio (δ34S) measurements to assess sulfide intrusion in the seagrass Halodule wrightii, a semi-tropical species found throughout the Gulf of Mexico, Caribbean Sea, and both western and eastern Atlantic coasts. We found a gradient in δ34S values (−5.58 ± 0.54‰+13.58 ± 0.30‰) from roots to leaves, in accordance with prior observations and those from other species. The results may also represent the first values reported for H. wrightii rhizome tissue. The presence of sulfide-derived sulfur in varying proportions (15–55%) among leaf, rhizome, and root tissues suggests H. wrightii is able to assimilate sedimentary H2S into non-toxic forms that constitute a significant portion of the plant’s total sulfur content.
“Return-to-player” information is used in several jurisdictions to display the long-run cost of gambling, but previous evidence suggests that these messages are frequently misunderstood by gamblers. Two ways of improving the communication of return-to-player information have been suggested: switching to an equivalent “house-edge” format, or via the use of a “volatility warning,” clarifying that the information applies only in the statistical long run. In this study, Australian participants (N = 603) were presented with either a standard return-to-player message, the same message supplemented with a volatility warning, or a house-edge message. The return-to-player plus volatility warning message was understood correctly more frequently than the return-to-player message, but the house-edge message was understood best of all. Participants perceived the lowest chance of winning in the return-to-player plus volatility warning condition. These findings contribute data on the relative merits of two proposed approaches in the design of improved gambling information.
The unfolded protein response has recently been implicated as a mechanism by which 1,10-phenanthroline-containing coordination compounds trigger cell death. We explored the interaction of two such compounds—one containing copper and one containing manganese—with endoplasmic reticulum (ER) stress. Pretreatment with anisomycin significantly enhanced the cytotoxic activity of both metal-based compounds in A2780, but only the copper-based compound in A549 cells. The effects of pretreatment with tunicamycin were dependent on the nature of the metal center in the compounds. In A2780 cells, the cytotoxic action of the copper compound was reduced by tunicamycin only at high concentration. In contrast, in A549 cells the efficacy of the manganese compound cells was reduced at all tested concentrations. Intriguingly, some impact of free 1,10-phenanthroline was also observed in A549 cells. These results are discussed in the context of the emerging evidence that the ER plays a role in the cytotoxic action of 1,10-phenanthroline-based compounds.
We have previously shown that the geographic routing’s greedy packet forwarding distance (PFD), in dissimilarity values of its average measures, characterizes a mobile ad hoc network’s (MANET) topology by node size. In this article, we demonstrate a distribution-based analysis of the PFD measures that were generated by two representative greedy algorithms, namely GREEDY and ELLIPSOID. The result shows the potential of the distribution-based dissimilarity learning of the PFD in topology characterizing. Characterizing dynamic MANET topology supports context-aware performance optimization in position-based or geographic packet routing.
Reducing negative attitudes toward older adults is an urgent issue. A previous study has conducted “stereotype embodiment theory”-based interventions (SET interventions) that present participants with the contents of SET and related empirical findings. I focus on the subjective time to become older (the perception of how long people feel it will be before they become old) as a mechanism for the effect of SET interventions. I make the SET intervention group and the control group in which the participants are presented with an irrelevant vignette. The data from 641 participants (M = 31.97 years) were analyzed. Consequently, the SET intervention shortened the subjective time to become older and reduced negative attitudes toward older adults. When considering SET interventions, it would be useful to focus not only on the self-interested motives to avoid age discrimination but also on the subjective time to become older.
Sexual propagation of Agave plants is an incipient cultivation method, these plants withstand drought and adverse growing conditions; therefore, research on Agave’s diversity, seed processing, and storage could support its cultivation on marginal lands. The aim of this work was to evaluate seed morphology, germination, and seedling genetic diversity of six seed origins (species × provenance) of Agave plants collected in five provenances from Mexico. Seed longevity was evaluated in two seed origins after a 10-year storage period. Seed morphology and seedling genetic variation results demonstrated intra- and interspecific variation within Agave salmiana and with the other seed origins, respectively. After a 10-year storage period seed germination of two A. salmiana seed origins remained relatively stable, storage conditions, and seed variables of this work can serve as reference parameters for future analyses. To the best authors’ knowledge, this is the first report of Agave’s seed longevity evaluation after a 10-year storage period.
The bootComb R package allows researchers to derive confidence intervals with correct target coverage for arbitrary combinations of arbitrary numbers of independently estimated parameters. Previous versions (<1.1.0) of bootComb used independent bootstrap sampling and required that the parameters themselves are independent—an unrealistic assumption in some real-world applications.
Findings
Using Gaussian copulas to define the dependence between parameters, the bootComb package has been extended to allow for dependent parameters.
Implications
The updated bootComb package can now handle cases of dependent parameters, with users specifying a correlation matrix defining the dependence structure. While in practice it may be difficult to know the exact dependence structure between parameters, bootComb allows running sensitivity analyses to assess the impact of parameter dependence on the resulting confidence interval for the combined parameter.
Numerical estimators of differential entropy and mutual information can be slow to converge as sample size increases. The offset Kozachenko–Leonenko (KLo) method described here implements an offset version of the Kozachenko–Leonenko estimator that can markedly improve convergence. Its use is illustrated in applications to the comparison of trivariate data from successive scene color images and the comparison of univariate data from stereophonic music tracks. Publicly available code for KLo estimation of both differential entropy and mutual information is provided for R, Python, and MATLAB computing environments at https://github.com/imarinfr/klo.
This study assessed neonatal visual maturity in infants with congenital heart disease (CHD) and its predictive value for neurodevelopmental outcomes. Neonates with CHD underwent a standardized visual assessment before and after cardiopulmonary bypass surgery. Visual maturity was rated as normal versus abnormal by means of normative reference data. Twelve-month neurodevelopment was assessed with the Bayley-III. Twenty-five healthy controls served as the reference group. Neonatal visual assessment was performed in five neonates with CHD preoperatively and in 24 postoperatively. Only postoperative assessments were considered for further analysis. Median [IQR] age at assessment was 27.0 [21.5, 42.0] days of life in postoperative neonates with CHD and 24.0 [15.0, 32.0] in controls. Visual performance was within reference values in 87.5% in postoperative CHD versus 90.5% in healthy controls (p = 1.0). Visual maturity was not predictive of neurodevelopment at 12 months. These results demonstrate the limited feasibility and predictive value of neonatal visual assessments in CHD.
Dual-purpose sorghum response to anthracnose disease, growth, and yield was undertaken in Derashe and Arba Minch trial sites during March–June 2018 and 2019. Five sorghum varieties and Rara (local check) were arranged in a randomized complete block design with four replications. Variety Chelenko exhibited the tallest main crop plant height (430 cm) while Dishkara was the tallest (196.65 cm) at ratoon crop harvesting. Rara had a higher tiller number (main = 6.73, ratoon = 9.73) among the varieties. Dishkara and Chelenko varieties produced 50 and 10% more dry biomass yield (DBY) than the overall mean DBY, while Konoda produced 40% less. Although the anthracnose infestation was highest on the varieties Konoda (percentage severity index [PSI] = 20.37%) and NTJ_2 (PSI = 32.19%), they produced significantly (p < .001) higher grain yield (3.89 t/ha) than others. Under anthracnose pressure, Chelenko and Dishkara varieties are suggested for dry matter yield while NTJ_2 for grain yield production in the study area and similar agroecology.
The creamatocrit is a simple technique for estimating the lipid content of milk, widely adopted for clinical and research purposes. We evaluated the effect of long-term cryogenic storage on the creamatocrit for human milk.
Methods
Frozen and thawed milk specimens (n = 18) were subjected to the creamatocrit technique. The specimens were reanalyzed after long-term cryogenic storage (10 years at <70°C). The correlation between pre- and post-storage values was tested, and their differences were analyzed using the Bland–Altman plot.
Results
The pre- and post-storage values were highly correlated (r = 0.960, p < .0001). The Bland–Altman plot revealed a positive association between their differences and means (Pitman’s test r = 0.743, p < .001), suggesting the presence of nonconstant bias across the creamatocrit range. Long-term storage of human milk may introduce subtle bias to the creamatocrit in replicating pre-storage values. Further research should evaluate whether this bias is statistically correctable.
During military operations, soldiers are required to successfully complete numerous physical and cognitive tasks concurrently. Understanding the typical variance in research tools that may be used to provide insight into the interrelationship between physical and cognitive performance is therefore highly important. This study assessed the inter-day variability of two military-specific cognitive assessments: a Military-Specific Auditory N-Back Task (MSANT) and a Shoot-/Don’t-Shoot Task (SDST) in 28 participants. Limits of agreement ±95% confidence intervals, standard error of the mean, and smallest detectable change were calculated to quantify the typical variance in task performance. All parameters within the MSANT and SDST demonstrated no mean difference for trial visit in either the seated or walking condition, with equivalency demonstrated for the majority of comparisons. Collectively, these data provided an indication of the typical variance in MSANT and SDST performance, while demonstrating that both assessments can be used during seated and walking conditions.
Statistical learning—the skill to pick up probability-based regularities of the environment—plays a crucial role in adapting to the environment and learning perceptual, motor, and language skills in healthy and clinical populations. Here, we developed a new method to measure statistical learning without any manual responses. We used the Alternating Serial Reaction Time (ASRT) task, adapted to eye-tracker, which, besides measuring reaction times (RTs), enabled us to track learning-dependent anticipatory eye movements. We found robust, interference-resistant learning on RT; moreover, learning-dependent anticipatory eye movements were even more sensitive measures of statistical learning on this task. Our method provides a way to apply the widely used ASRT task to operationalize statistical learning in clinical populations where the use of manual tasks is hindered, such as in Parkinson’s disease. Furthermore, it also enables future basic research to use a more sensitive version of this task to measure predictive processing.
At the microscale, the motion of atoms and molecules composing matter is governed by Hamiltonian dynamics. For classical systems, this motion is described as trajectories in the phase space of the positions and momenta of the particles. Different equilibrium and nonequilibrium statistical ensembles can be introduced, each associated with some probability distribution, which is a solution of Liouville’s equation. The BBGKY hierarchy of equations is obtained for the multiparticle distribution functions. The presentation includes the properties of ergodicity and dynamical mixing, the Pollicott–Ruelle resonances, microreversibility, and the nonequilibrium breaking of time-reversal symmetry at the statistical level of description. The concept of entropy is introduced by coarse graining. Linear response theory is developed within the classical framework, leading to the Onsager–Casimir reciprocal relations and the fluctuation–dissipation theorem. The projection-operator methods are summarized.
At the mesoscale, reaction networks are described in terms of stochastic processes. In well-stirred solutions, the time evolution is ruled by the chemical master equation for the probability distribution of the random numbers of molecules. The entropy production is obtained for these reactive processes in the framework of stochastic thermodynamics. The entropy production can be decomposed using the Hill–Schnakenberg cycle decomposition in terms of the affinities and the reaction rates of the stoichiometric cycles of the reaction network. The multivariate fluctuation relation is established for the reactive currents. The results are applied to several examples of reaction networks, in particular, describing autocatalytic bistability, noisy chemical clocks, enzymatic kinetics, and copolymerization processes.