A comprehensive study in efficacy of Vietnamese herbal extracts on whiteleg shrimp (<em>Penaeus vannamei</em>) against <em>Vibrio parahaemolyticus</em> causing acute hepatopancreatic necrosis disease (AHPND)

Traditional Vietnamese herbal species were examined for their antimicrobial activity and disease resistance in whiteleg shrimp. In-vitro screening, the extracts of ten herbs were conducted to test the inhibition ability against Vibrio parahaemolyticus, causing acute hepatopancreatic necrosis disease. The results showed that five out of ten herbal species, including Pithecellobium dulce, Melaleuca leucadendron, Eucalyptus globulus, Mimosa pirga, and Hibiscus sabdariffa displayed potent antibacterial activity. Besides, three types of extracts of H. sabdariffa, E. globulus, and M. pirga were coated to the pellet feed at a concentration of 1%. After 30 days of feeding, the whiteleg shrimp (Penaeus vannamei) were challenged by V. parahaemolyticus through immersion. The growth performance (such as growth rate in length and weight, survival rate), hematological parameters of total hemocytes (THC), hyaline hemocytes (HC), and granulocytes (GC), and hepatopancreas recovery under the treatments with herbal extracts of the whiteleg shrimp were significantly enhanced as compared with the control (without herbal extract). The mortality and the bacterial density in the hepatopancreas of shrimp decreased. Specifically, the mortality of shrimp in the treatment supplemented with the methanol extract of H. sabdariffa was the lowest, followed by M. pirga and E. globulus. The experimental results also indicated that H. sabdariffa, E. globulus, and M. pirga could improve immune parameters and disease resistance; therefore, they should be employed in sustainable shrimp, practical farming

Phase Stability Effects on Hydrogen Embrittlement Resistance in Martensite–Reverted Austenite Steels

Earlier studies have shown that interlath austenite in martensitic steels can enhance hydrogen embrittlement (HE) resistance. However, the improvements were limited due to microcrack nucleation and growth. A novel microstructural design approach is investigated, based on enhancing austenite stability to reduce crack nucleation and growth. Our findings from mechanical tests, X-ray diffraction, and scanning electron microscopy reveal that this strategy is successful. However, the improvements are limited due to intrinsic microstructural heterogeneity effects

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

О представимости операторного уравнения с производной порядка n по времени в форме уравнения Лагранжа-Остроградского

In the paper, the representability of an operator equation with the n-th derivative with respect to time in the form of the Lagrange-Ostrogradskii equation is investigated.В работе исследована представимость операторного уравнения с производной порядка n по времени в форме уравнения Лагранжа-Остроградского

On Connection between Variationality of a Six-Order Ordinary Differential Equation and Hamilton–Ostrogradskii Equations

Abstract: In the paper, we investigate the representability of a six-orderordinary differential equation in the form ofHamilton–Ostrogradskii equations. For this purpose, potentialityconditions are obtained and the correspondingHamilton–Ostrogradskii action is constructed. © 2021, Pleiades Publishing, Ltd

О некоторых свойствах системы уравнений диффузии

The nonpotentiality of the operator of a boundary value problem for a diffusion system of partial differential equations with respect to the classical bilinear form is proved. It is shown that this system does not admit a matrix variational multiplier of the given form.Доказана непотенциальность оператора краевой задачи для диффузионной системы уравнений в частных производных относительно классической билинейной формы. Показано, что эта система не допускает матричный вариационный множитель заданной формы

Continuous Property Gradation for Multi-Material 3D-Printed Objects

Modern AM processes allow for printing multiple materials. The resulting objects can be stiff/dense in some areas and soft/porous in others, resulting in distinct physical properties. However, modeling material gradients is still tedious with current approaches, especially when smooth transitions are required. Current approaches can be distinguished into a) NURBS-BReps-based and b) voxel-based. In case of NURBS-BReps, discrete material distributions can be modeled by manually introducing separate shells inside the object; smooth gradation can only be approximated in discrete steps. For voxel representations, gradation is discrete by design and comes along with an approximation error. In addition, interacting on a per-voxel basis is tedious for the designer/engineer. We present a novel approach for representing material gradients in volumetric models using subdivision schemes, supporting continuity and providing elegant ways for interactive modeling of locally varying properties. Additionally, the continuous volumetric representation allows for on-demand sampling at any resolution required by the 3D printer.Mechanical Engineerin

Isolation and characterization of a DREB homolog gene from a local drought-tolerant maize cultivar

Clarifying the genetic background of the drought-tolerance trait is a crucial task that may help to improve plant performance under stress by a genetic engineering approach. dehydration-responsive element-binding protein (dREB) is a transcription factor family which modulates many stress-responsive genes. In this study, we isolated a DrEB homolog gene named ZmDrEBtv from Zea mays var. Tevang-1. Using bioinformatic tools, a number of Indels and SNPs in ZmDrEBtv sequence different from the reference accession were identified. In addition, based on deduced protein sequence similarity, ZmdREBtv was assigned to transcription factor dREB2 class as featured by a conserved dNa binding domain – aP2. The ZmDrEBtv construct under thecontrol of the rd29a promoter was transformed into a drought-sensitive maize plant, K7 line. The transgenic plants were assessed with reference to molecular and phenotypic characteristics related to the drought-tolenrance trait. The results proved that the maize plants carrying ZmDrEBtv gene showed enhanced tolerance and better performance to the water-deficit environment at different stages, compared to the wild-type plants