On the Second-order Frechet Derivatives of Eigenvalues of Sturm-Liouville Problems in Potentials

The works of V. A. Vinokurov have shown that eigenvalues and normalized eigenfunctions of Sturm-Liouville problems are analytic in potentials, considered as mappings from the Lebesgue space to the space of real numbers and the Banach space of continuous functions respectively. Moreover, the first-order Frechet derivatives are known and paly an important role in many problems. In this paper, we will find the second-order Frechet derivatives of eigenvalues in potentials, which are also proved to be negative definite quadratic forms for some cases.Comment: 10 page

An Instrument for In Situ Measuring the Volume Scattering Function of Water: Design, Calibration and Primary Experiments

The optical volume scattering function (VSF) of seawater is a fundamental property used in the calculation of radiative transfer for applications in the study of the upper-ocean heat balance, the photosynthetic productivity of the ocean, and the chemical transformation of photoreactive compounds. A new instrument to simultaneously measure the VSF in seven directions between 20° to 160°, the attenuation coefficient, and the depth of water is presented. The instrument is self-contained and can be automatically controlled by the depth under water. The self-contained data can be easily downloaded by an ultra-short-wave communication system. A calibration test was performed in the laboratory based on precise estimation of the scattering volume and optical radiometric calibration of the detectors. The measurement error of the VSF measurement instrument has been estimated in the laboratory based on the Mie theory, and the average error is less than 12%. The instrument was used to measure and analyze the variation characteristics of the VSF with angle, depth and water quality in Daya Bay for the first time. From these in situ data, we have found that the phase functions proposed by Fournier-Forand, measured by Petzold in San Diego Harbor and Sokolov in Black Sea do not fit with our measurements in Daya. These discrepancies could manly due to high proportion of suspended calcium carbonate mineral-like particles with high refractive index in Daya Bay

Single-pixel computational ghost imaging with helicity-dependent metasurface hologram

A helicity-dependent computational ghost image generated by a metasurface hologram offers a promising optical encryption scheme.</jats:p

Dopamine Release Dynamics Change during Adolescence and after Voluntary Alcohol Intake

Adolescence is associated with high impulsivity and risk taking, making adolescent individuals more inclined to use drugs. Early drug use is correlated to increased risk for substance use disorders later in life but the neurobiological basis is unclear. The brain undergoes extensive development during adolescence and disturbances at this time are hypothesized to contribute to increased vulnerability. The transition from controlled to compulsive drug use and addiction involve long-lasting changes in neural networks including a shift from the nucleus accumbens, mediating acute reinforcing effects, to recruitment of the dorsal striatum and habit formation. This study aimed to test the hypothesis of increased dopamine release after a pharmacological challenge in adolescent rats. Potassium-evoked dopamine release and uptake was investigated using chronoamperometric dopamine recordings in combination with a challenge by amphetamine in early and late adolescent rats and in adult rats. In addition, the consequences of voluntary alcohol intake during adolescence on these effects were investigated. The data show a gradual increase of evoked dopamine release with age, supporting previous studies suggesting that the pool of releasable dopamine increases with age. In contrast, a gradual decrease in evoked release with age was seen in response to amphetamine, supporting a proportionally larger storage pool of dopamine in younger animals. Dopamine measures after voluntary alcohol intake resulted in lower release amplitudes in response to potassium-chloride, indicating that alcohol affects the releasable pool of dopamine and this may have implications for vulnerability to addiction and other psychiatric diagnoses involving dopamine in the dorsal striatum

Seismic Behavior and Finite Element Analysis of Reinforced Concrete Short Columns Impacted by Oblique Earthquakes

This study evaluates the seismic behavior of reinforced concrete (RC) short columns with a high axial compression ratio under oblique earthquake conditions. The studied parameters include the loading angle, axial compression ratio, the high-strength stirrups with small spacing, and the carbon-fiber-reinforced polymer (CFRP) wrapped column end or outer steel plate mesh at the end of the column. Low-cycle repeated loading tests were used to analyze the specimens’ seismic performance indices of hysteretic behavior, strength, stiffness, deformation capacity, and energy dissipation capacity. Results suggest that the OpenSees finite element program can sufficiently simulate the nonlinear response of the specimen. Oblique loading led to the increase of damage to the specimens and the deterioration of stiffness of the specimens, which was especially seen with the increase of the axial compression ratio. Accordingly, arranging high-strength stirrups with small spacing and the column end outer steel plate mesh both transform the failure mode from shear failure to bending shear failure. Additionally, wrapping the CFRP at the end of columns improves their strength but does not improve their deformation capacity. The demonstrated success of these strategies in improving the seismic performance of RC short columns under diagonal loads with high axial compression ratios can inform practical engineering applications

Molecular Variation of Satellite DNAβ Molecules Associated with Malvastrum yellow vein virus and Their Role in Pathogenicity▿ †

Previous studies have found that the diversity of begomovirus-associated DNAβ satellites is related to host and geographical origin. In this study, we have cloned and sequenced 20 different isolates of DNAβ molecules associated with Malvastrum yellow vein virus (MYVV) isolated from Malvastrum coromandelianum plants in different geographical locations of Yunnan Province, China. Analyses of their molecular variation indicate that the satellites are clustered together according to their geographical location but that they have only limited sequence diversity. Infectivity tests using infectious clones of MYVV and its associated DNAβ molecule indicate that MYVV DNAβ is indispensable for symptom induction in Nicotiana benthamiana, N. glutinosa, Petunia hybrida, and M. coromandelianum plants. Furthermore, we showed that MYVV interacts functionally with heterologous DNAβ molecules in N. benthamiana plants

Organization and Regulation of Soybean SUMOylation System under Abiotic Stress Conditions

Covalent attachment of the small ubiquitin-related modifier, SUMO, to substrate proteins plays a significant role in plants under stress conditions, which can alter target proteins' function, location, and protein-protein interactions. Despite this importance, information about SUMOylation in the major legume crop, soybean, remains obscure. In this study, we performed a bioinformatics analysis of the entire soybean genome and identified 40 genes belonged to six families involved in a cascade of enzymatic reactions in soybean SUMOylation system. The cis-acting elements analysis revealed that promoters of SUMO pathway genes contained different combinations of stress and development-related cis-regulatory elements. RNA-seq data analysis showed that SUMO pathway components exhibited versatile tissue-specific expression patterns, indicating coordinated functioning during plant growth and development. qRT-PCR analysis of 13 SUMO pathway members indicated that majority of the SUMO pathway members were transcriptionally up-regulated by NaCl, heat and ABA stimuli during the 24 h period of treatment. Furthermore, SUMOylation dynamics in soybean roots under abiotic stress treatment were analyzed by western blot, which were characterized by regulation of SUMOylated proteins. Collectively, this study defined the organization of the soybean SUMOylation system and implied an essential function for SUMOylation in soybean abiotic stress responses

Schiff base nanoarchitectonics for supramolecular assembly of dipeptide as drug carriers

Development of peptide-based supramolecular materials with hierarchical morphology and tunable guest loading displays broad potential as drug carrier in view of biocompatibility and biodegradability. Herein, we report a facile Schiff base nanoarchitectonic for supramolecular assembly of diphenylalanine (FF) metastable gel. The addition of trace glutaraldehyde (GA)/H2O solution induces the Schiff base reaction between GA and FF accompanying by phase transition from gel to solution. FF nanoparticles and hierarchical beaded nanofibers with autofluorescence properties can be constructed by regulating the competitive assembly between FF-H2O and FF-GA oligomer. Moreover, various guest molecules with different hydrophilic and hydrophobic properties can be easily loaded into such assembled particles and its release can be triggered under weak alkaline conditions, which show the potential application of the assembled FF system as drug carriers. (c) 2022 Elsevier Inc. All rights reserved