Filament Nucleation Tunes Mechanical Memory in Active Polymer Networks

Incorporating growth into contemporary material functionality presents a grand challenge in materials design. The F‐actin cytoskeleton is an active polymer network that serves as the mechanical scaffolding for eukaryotic cells, growing and remodeling in order to determine changes in cell shape. Nucleated from the membrane, filaments polymerize and grow into a dense network whose dynamics of assembly and disassembly, or “turnover,” coordinates both fluidity and rigidity. Here, the extent of F‐actin nucleation is varied from a membrane surface in a biomimetic model of the cytoskeleton constructed from purified protein. It is found that nucleation of F‐actin mediates the accumulation and dissipation of polymerization‐induced F‐actin bending energy. At high and low nucleation, bending energies are low and easily relaxed yielding an isotropic material. However, at an intermediate critical nucleation, stresses are not relaxed by turnover and the internal energy accumulates 100‐fold. In this case, high filament curvatures template further assembly of F‐actin, driving the formation and stabilization of vortex‐like topological defects. Thus, nucleation coordinates mechanical and chemical timescales to encode shape memory into active materials.     

Antioxidant profiling of native and modified cereal brans

Bran is detached from cereals during roller-milling operations and considered as a byproduct of milling. Bran carries phenolics and antioxidants in appreciable quantities which can be heightened by modification. In the present project, four cereals were under study that is, wheat, barley, millet and sorghum. Bran was separated from cereal grains and was subjected to size reduction that is, fine (1 mm) and coarse (2 mm) and enzymatic modification by using xylanase and cellulase. Total phenolic content (TPC), total flavonoids content (TFC) and phytic acid were determined spectrophotometrically and phenolic acids through HPLC. TPC and TFC were recorded highest in xylanase-treated millet bran (0.304 mg GAE g⁻¹ and 211.42 μg g⁻¹ QE respectively). In vitro antioxidant activity assessed by DPPH and FRAP was found to be highest in coarse millet bran (89.51% inhibition) and native sorghum bran (722.52 μMFeSO4 g⁻¹) respectively. Phytic acid was observed highest in xylanase-treated barley bran (5.80 g per 100 g).     

Distribution of Phenolic Acids in Milling Fractions of Spring Wheats

The core objective of the current research was to determine the phenolic acids through High performance liquid chromatography (HPLC) in milling fractions of spring wheats, i.e., bran, shorts, break, and reduction flour. In wheat bran, caffeic, p-coumaric, syringic, and ferulic acid ranged from 0.93 to 1.5, 24 to 32.00, 55.30 to 94, and 137.25 to 180.30 μg/g, respectively. Maximum caffeic acid (0.33 μg/g), p-coumaric acid (12.12 μg/g), and ferulic acid content (29.12 μg/g) were found in the reduction flour of Sehar-2006. Furthermore, whole wheat flour of Shafaq-2006 revealed maximum caffeic acid (1.8 μg/g), p-coumaric acid (22.3 μg/g), and syringic acid (47.07 μg/g). Since antioxidant activity is directly related with phenolic acids, it was decreased (43.26 to 74.40%) in cookies with the decrease in phenolic acids during storage. Moreover, phenolic acids hold potential to be extracted and utilized in cereal-based products for best quality and value addition.     

Some properties of Rényi entropy and Rényi entropy rate

In this paper, we define the conditional Rényi entropy and show that the so-called chain rule holds for the Rényi entropy. Then, we introduce a relation for the rate of Rényi entropy and use it to derive the rate of the Rényi entropy for an irreducible-aperiodic Markov chain. We also show that the bound for the Rényi entropy rate is simply the Shannon entropy rate.     

K-means tree: an optimal clustering tree for unsupervised learning

The Journal of Supercomputing - Tree construction is one of the popular methods for tackling any supervised task in machine learning. However, there has been little effort in applying trees for...     

A study on inspection schemes in optimal design of control charts for deteriorating processes

The non-uniform inspection scheme obtained by the constant integrated hazard procedure overcomes the uniform scheme economically in optimal design of control charts. The comperative study is generalized in this paper to an optimization problem which looks for the optimal sampling points among all possible sampling schemes. The objective function is simplified here by modelling sequential time intervals as a family of functions of the first sampling interval, which also has been induced by the constant integrated hazard approach. The study demonstrates the model implementation through the economic design of $\overline{X}$ and T²-Hotelling control charts, both under the two widely used process failure mechanisms, that is, Weibull and Chen distributions. A comprehensive numerical investigation illustrates the possibility of existence of sampling schemes which outperform the constant integrated hazard approach and emphasizes the necessity of further investigation into the solution procedure.