Existence and Iteration of Positive Solutions for One-Dimensional p-Laplacian Boundary Value Problems with Dependence on the First-Order Derivative

This paper deals with the existence and iteration of positive solutions for the following one-dimensional p-Laplacian boundary value problems: (Õp(u′(t)))′+a(t)f(t,u(t),u′(t))=0, t∈(0,1), subject to some boundary conditions. By making use of monotone iterative technique, not only we obtain the existence of positive solutions for the problems, but also we establish iterative schemes for approximating the solutions

Decoupling of nutrient stoichiometry in Suaeda glauca (Bunge) senesced leaves under salt treatment

The stoichiometry of senesced leaves is pivotal in nutrient cycling and can be significantly influenced by soil salinization, a rising global issue threatening the functionality of ecosystems. However, the impacts of soil salinization on senesced leaf stoichiometry are not fully understood. In this study, we conducted a pot experiment with varying soil salt concentrations to examine their influence on the concentrations and stoichiometric ratios of nitrogen (N), phosphorus (P), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), and zinc (Zn) in the senesced leaves of Suaeda glauca (Bunge). Compared to the control group, salt treatments significantly enhanced Na concentration while diminishing the concentrations of K, Ca, Mg, Zn, N, and P. Interestingly, as salinity levels escalated, N concentration maintained stability, whereas P concentration exhibited an increasing trend. Moreover, K, Ca, and Mg significantly declined as salt levels rose. Salt treatments brought about significant changes in stoichiometric ratios, with the N:P, K:Na, N:Na, N:Mg, and Ca : Mg ratios dropping and the N:Ca and N:K ratios rising, illustrating the varying nutrient coupling cycles under different salt conditions. These findings shed light on the plasticity of stoichiometric traits in S. glauca senesced leaves in response to soil salinization shifts, which could potentially offer insights into nutrient cycling reactions to soil salinization

Reproducing the Velocity Vectors in the Listening Region

This paper proposes a sound field reproduction algorithm based on matching the velocity vectors in a spherical listening region. Using the concept of sound field translation, the spherical harmonic coefficients of the velocity vectors in a spherical region are derived from the desired pressure distribution. The desired pressure distribution can either correspond to sources such as plane waves and point sources, or be obtained from measurements using a spherical microphone array. Unlike previous work in which the velocity vectors are only controlled on the boundary of the listening region or at discrete sweet spots, this work directly manipulates the velocity vectors in the whole listening region, which is expected to improve the perception of the desired sound field at low frequencies.Comment:

An improved particle swarm optimization algorithm for dynamic job shop scheduling problems with random job arrivals

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Random job arrivals that happen frequently in manufacturing practice may create a need for dynamic scheduling. This paper considers an issue of how to reschedule the randomly arrived new jobs to pursue both performance and stability in a job shop. Firstly, a mixed integer programming model is established to minimize three objectives, including the discontinuity rate of new jobs during the processing, the makespan deviation of initial schedule, and the sequence deviation on machines. Secondly, four match-up strategies from references are modified to determine the rescheduling horizon. Once new jobs arrive, the rescheduling process is immediately triggered with ongoing operations remain. The ongoing operations are treated as machine unavailable constraints (MUC) in the rescheduling horizon. Then, a particle swarm optimization (PSO) algorithm with improvements is proposed to solve the dynamic job shop scheduling problem. Improvement strategies consist of a modified decoding scheme considering MUC, a population initialization approach by designing a new transformation mechanism, and a novel particle movement method by introducing position changes and a random inertia weight. Lastly, extensive experiments are conducted on several instances. The experiments results show that the modified rescheduling strategies are statistically and significantly better than the compared strategies. Moreover, comparative studies with five variants of PSO algorithm and three state-of-the-art meta-heuristics demonstrate the high performance of the improved PSO algorithm

Preparation and in Vitro Digestive Analysis of Casein-Derived Peptide-Zinc Chelates

In this study, casein peptides were obtained by alcalase hydrolyzation and Lactobacilus fermentation to prepare the casein peptide-zinc chelates, which are a kind of efficient and well-absorbed zinc supplement. The structure of casein peptide-zinc chelates was characterized by spectroscopic instruments. The digestive stability and safety were also assayed using in vitro digestive model and Caco-2 cell experiment. The results indicated that the optimal conditions for preparing casein peptides were as follows: Volume of alcalase was 0.3% (w/v), pH of reaction system was 9.0, Lactobacilus fermentation time was 12 h. Under this condition, the peptide content was 142.39±0.95 mg/g, and the zinc chelation rate was 31.41%±0.97%. The chelation with zinc destroyed the structure of casein peptides leading to a loose surface structure. Spectroscopic analysis showed that Zn2+ can bind to the reactive groups on casein peptides, with the chelating sites being carboxyl oxygen, hydroxyl oxygen and amino groups. The results of in vitro digestion showed that casein peptide-zinc chelates possessed better solubility than that of zinc sulfate. After gastrointestinal digestion, the DPPH and ABTS+ scavenging ability of casein peptide-zinc chelates increased by 26.19%±3.30% and 71.96%±7.06%, respectively. However, the ferric ion reducing power of the casein peptide-zinc chelates decreased by 36.26%±2.80%. At the same time, the β-turn and random coil content of the casein peptide-zinc chelate decreases during digestion, the β-sheet structure increases and Zn2+ play a role in maintaining the peptide structure. Furthermore, the cytotoxicity test indicated that casein peptide-zinc chelates gastrointestinal digest were toxic to Caco-2 cells when the concentration exceeded 0.4 mg/mL. Finally, 15 and 13 dairy-derived peptides were identified from casein hydrolysate and casein peptide-zinc chelates, respectively, using mass spectrometry. These results will provide scientific evidence for the development and application of efficient casein peptide-zinc chelates

Solution structure of the second bromodomain of Brd2 and its specific interaction with acetylated histone tails

<p>Abstract</p> <p>Background</p> <p>Brd2 is a transcriptional regulator and belongs to BET family, a less characterized novel class of bromodomain-containing proteins. Brd2 contains two tandem bromodomains (BD1 and BD2, 46% sequence identity) in the N-terminus and a conserved motif named ET (extra C-terminal) domain at the C-terminus that is also present in some other bromodomain proteins. The two bromodomains have been shown to bind the acetylated histone H4 and to be responsible for mitotic retention on chromosomes, which is probably a distinctive feature of BET family proteins. Although the crystal structure of Brd2 BD1 is reported, no structure features have been characterized for Brd2 BD2 and its interaction with acetylated histones.</p> <p>Results</p> <p>Here we report the solution structure of human Brd2 BD2 determined by NMR. Although the overall fold resembles the bromodomains from other proteins, significant differences can be found in loop regions, especially in the ZA loop in which a two amino acids insertion is involved in an uncommon <it>π</it>-helix, termed <it>π</it>D. The helix <it>π</it>D forms a portion of the acetyl-lysine binding site, which could be a structural characteristic of Brd2 BD2 and other BET bromodomains. Unlike Brd2 BD1, BD2 is monomeric in solution. With NMR perturbation studies, we have mapped the H4-AcK12 peptide binding interface on Brd2 BD2 and shown that the binding was with low affinity (2.9 mM) and in fast exchange. Using NMR and mutational analysis, we identified several residues important for the Brd2 BD2-H4-AcK12 peptide interaction and probed the potential mechanism for the specific recognition of acetylated histone codes by Brd2 BD2.</p> <p>Conclusion</p> <p>Brd2 BD2 is monomeric in solution and dynamically interacts with H4-AcK12. The additional secondary elements in the long ZA loop may be a common characteristic of BET bromodomains. Surrounding the ligand-binding cavity, five aspartate residues form a negatively charged collar that serves as a secondary binding site for H4-AcK12. We suggest that Brd2 BD1 and BD2 may possess distinctive roles and cooperate to regulate Brd2 functions. The structure basis of Brd2 BD2 will help to further characterize the functions of Brd2 and its BET members.</p

Interrogation of Ultra-weak FBG Array using Double-pulse and Heterodyne Detection

A high performance interrogation method for ultra-weak FBG (UWFBG) using double-pulse and heterodyne detection method is proposed. The perturbation along the UWFBG array is located quickly through the use of double-pulsed optical input waveform. Then the perturbation of fiber is quantified precisely by demodulating the phase of differential signals from a heterodyne configuration. The efficiency of measuring the perturbation is improved by more than 20 times than that of using single probe pulse. In comparison with conventional Rayleigh scattering based approach, the proposed method is supreme in signal-to-noise ratio (SNR), approximately 18 dB higher. The use of differential signaling method can effectively remove the influence from frequency drift of the laser source, making this proposed method capable of measuring low frequency vibration. In our experiment, perturbations with both sinusoidal and triangle waveform were generated to quantitatively evaluate the performance of the proposed method. The minimum detectable fiber length variation is 14.85 nm, and the sensing frequency can be as low as 0.2 Hz