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This paper describes a 2-stage tactic for achieving an odd-order variable-bandwidth (OO-VBW) filter with absolutely guaranteed stability. The design methodology aims to minimize the p-norm amplitude-response error while maintaining the OO-VBW-filter's stability. In order to tune OO-VBW filter's amplitude response, we utilize a kind of functions of the bandwidth (BW)-tuning parameter to express the filter's coefficients. Because those functions have changeable function values, the designed OO-VBW-filter's amplitude response possesses variability. Another important concern in this paper is the stability issue. When the filter coefficient values expressed as function values are changed, the OO-VBW filter that has feedback structures may become unstable. This necessitates that the OO-VBW-filter's stability must always be preserved during real-time tuning. In order to stabilize such an OO-VBW filter that has feedback structures, a coefficient-conversion (CC) algorithm is adopted, and it is incorporated into the 2-stage methodology for obtaining the OO-VBW filter. To illustrate both the stability and high approximation accuracy, the design of an OO-VBW bandpass filter is simulated. The simulation details verify that both stability and high accuracy can be successfully achieved.

Abstract The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a notorious pest in agriculture that has developed resistance to almost all chemical types used for its control. Here, we assembled a chromosome-level genome for the TSSM using Illumina, Nanopore, and Hi-C sequencing technologies. The assembled contigs had a total length of 103.94 Mb with an N50 of 3.46 Mb, with 87.7 Mb of 34 contigs anchored to three chromosomes. The chromosome-level genome assembly had a BUSCO completeness of 94.8%. We identified 15,604 protein-coding genes, with 11,435 genes that could be functionally annotated. The high-quality genome provides invaluable resources for the genetic and evolutionary study of TSSM.

This study explored the effect of commercial ripened Pu-erh tea (Y562, China Tea (Yunnan) Industry Co. Ltd.) on improving the health of populations with abnormal glucose and lipid metabolism. Qualified volunteers were recruited for nutritional epidemiological and clinical intervention studies. The volunteers were asked to drink the tea for three months. Their body composition (body mass, body mass index (BMI), body fat ratio and visceral fat), body circumferences (waist circumference, hip circumference and neck circumference), glucose metabolism-related indicators (fasting blood glucose, insulin, C-peptide, glycosylated hemoglobin), lipid metabolism-related indicators (total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A1 and B), blood uric acid levels, liver fat contents, and gut microbiota were tested and compared before and after drinking the tea to explore its health benefits. The results showed that after drinking Y562 without any change in diet or exercise for three months, the body mass, BMI, body circumferences, blood lipids (high-density lipoprotein cholesterol, apolipoprotein A1 and B), and liver fat contents of the volunteers were significantly improved (P 0.05). Moreover, the gut microbiota was improved, showing increased uniformity. The relative abundance of Lactobacillus, Clostridium, Akkermansia muciniphila, Clostridium screenens and Streptococcus thermophilus was increased, while that of Streptococcus, Lactococcus, Bacteroides, Bifidobacterium and Paraacteroides distasonis was decreased. This study suggests that ripened Pu-erh tea Y562 has the potential to help reduce the body mass, improve the body shape, reduce blood glucose and lipids, and alleviate non-alcoholic fatty liver disease (NAFLD). The underlying mechanism may be related to the regulation of the intestinal microecology and the bile acid pathways by Pu-erh tea.

This paper proposes a nonlinear optimization method for designing a high-order recursive allpass digital phase system that comprises several cascade-connected second-order (SO) allpass sections. This method first splits a given phase design specification (approximation target) into a set of equal sub-specifications, and then the equal sub-specification acts as the ideal phase for each of the SO sections. Since an SO section can be designed via employing a linear programming to minimize a linear fractional error function, this splitting process generates an excellent starting point (good initial values for the coefficients of the cascaded SO sections) for further minimizing the overall approximation error. This paper first derives a wide variety of fractional polynomial error functions for designing cascade-connected allpass phase systems of different high orders, and then shows that a high-order cascade-connected allpass phase system can be designed by utilizing a nonlinear solver to minimize the peak deviation of such a fractional polynomial error. Using the derived fractional polynomial error functions in the system design enables the system designer to find an excellent starting point for further minimizing the approximation error and thus reach a convergent design solution. This paper first derives a set of fractional polynomial errors, and then adopts the eighth-order cascade-connected phase system design to exemplify the effectiveness of the fractional-polynomial-error-based design tactic. Furthermore, the stability of the cascade-connected high-order allpass system can be readily checked via confirming that all of the cascaded SO sections have their poles inside the unit circle in the complex plane.

ABSTRACTThis paper shows a 2-step procedure for obtaining a variable-bandwidth recursive digital filter whose structure contains cascaded second-order (2nd-order) sections. Such a cascade-form structure is insensitive to the round-off noises that come from filter-coefficient quantizations in hardware implementations. This paper also shows how to utilize a 2-step procedure to get a variable-bandwidth recursive filter that is absolutely stable. The first step (Step-1) of the 2-step procedure designs a series of constant-bandwidth filters for approximating a series of evenly discretized variable specifications, and the second step (Step-2) fits the coefficient values obtained from Step-1 by employing individual polynomials. To ensure the stability of the resultant constant-bandwidth filters in Step-1, coefficient transformations are first executed on the 2nd-order transfer function's denominator-coefficients, and then each coefficient of both numerator and transformed denominator is found as an individual polynomial. Once all the polynomials are obtained, the polynomials corresponding to the transformed denominator are further converted to composite functions for ensuring the stability. Hence, the 2-step procedure not only produces a cascade-form variable-bandwidth filter that has low quantization errors, but also ensures the stability. A lowpass example is included for verifying the achieved stability and showing the high approximation accuracy.

The indirect preparation of oleogels by the aerogel template method has received widespread attention due to its advantages such as simple operation and excellent performance. In this study, composite aerogels of carboxy methyl cellulose-Na (CMC-Na) and soybean protein isolate (SPI) were prepared by the electrostatic interaction between them. The effects of different protein contents on the average particle size, microstructure, Fourier transform infrared (FTIR) spectrum, oil absorption kinetics, oil absorption capacity and oil holding capacity of aerogels were investigated. The oleogels prepared based on aerogel templates were characterized for their textural properties, antibacterial properties, and storage stability. The results showed that SPI and CMC-Na formed stable complexes through electrostatic interactions, and the average particle size of the complexes increased with protein content. The composite aerogel displayed a denser porous network structure along with improved oil-holding capacity, but had unfavorable effects on oil absorption performance. Moreover, the addition of protein improved the strength and Young’s modulus, and enhanced the antibacterial effect and storage stability of the oleogel. Therefore, the aerogel template method is good for preparing oleogels and a stable oleogel system can be prepared by electrostatic adsorption between polysaccharides and proteins.

This paper first presents six (6) types of benchmark amplitude design specifications, including variable low-pass specification, variable high-pass specification, variable bandpass specification, variable bandstop specification, variable notch-frequency specification, and variable notch-width specification. The design specifications can be taken as typical benchmark specifications targeted at testing as well as validating the effectiveness of various newly developed algorithms for designing various typical variable filters (VFs). Then, the paper provides a novel unity-bounded (UB) function developed for ensuring the stability of those VFs with recursive structures. Finally, a wide variety of simulation results are included for validating the design performance as well as the assured stability by using both the benchmark design specifications and the novel UB function.