Biotransformation of major ginsenosides into compound K by a new Penicillium dipodomyicola strain isolated from the soil of wild ginseng

A new strain, GH9, having ß-glucosidase activity was isolated from the soil of wild ginseng using Esculin-R2A agar. It shows the strongest activities to convert ginsenoside Rb1 to minor ginsenosides compound K. The transformation products were identified by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), and strain GH9 was found to transform major ginsenoside to minor ginsenoside compound K as the key sole product. The optimal biotransformation conditions of GH9 with C-K were obtained as follows: media, yeast broth (YB); transforming temperature, 40°C; pH of the medium, 4 - 6; transforming time, 7 days. At these optimum conditions, the maximum yield was 86.1%. Strain GH9 was identified as a Penicillium dipodomyicola species based on the internal transcribed spacers (ITS) ITS1-5.8S-ITS2 rRNA gene sequences constructed phylogenetic trees.Key words: Biotransformation, Panax ginseng, ginsenoside Rb1, ginsenoside compound K, minor ginsenoside

Coded Computing for Half-Duplex Wireless Distributed Computing Systems via Interference Alignment

Distributed computing frameworks such as MapReduce and Spark are often used to process large-scale data computing jobs. In wireless scenarios, exchanging data among distributed nodes would seriously suffer from the communication bottleneck due to limited communication resources such as bandwidth and power. To address this problem, we propose a coded parallel computing (CPC) scheme for distributed computing systems where distributed nodes exchange information over a half-duplex wireless interference network. The CPC scheme achieves the multicast gain by utilizing coded computing to multicast coded symbols {intended to} multiple receiver nodes and the cooperative transmission gain by allowing multiple {transmitter} nodes to jointly deliver messages via interference alignment. To measure communication performance, we apply the widely used latency-oriented metric: \emph{normalized delivery time (NDT)}. It is shown that CPC can significantly reduce the NDT by jointly exploiting the parallel transmission and coded multicasting opportunities. Surprisingly, when $K$ tends to infinity and the computation load is fixed, CPC approaches zero NDT while all state-of-the-art schemes achieve positive values of NDT. Finally, we establish an information-theoretic lower bound for the NDT-computation load trade-off over \emph{half-duplex} network, and prove our scheme achieves the minimum NDT within a multiplicative gap of $3$, i.e., our scheme is order optimal.Comment: 17 pages, 6 figure

Coded Caching Scheme for Partially Connected Linear Networks Via Multi-antenna Placement Delivery Array

In this paper, we study the coded caching scheme for the $(K,L,M_{\text{T}},M_{\text{U}},N)$ partially connected linear network, where there are $N$ files each of which has an equal size, $K+L-1$ transmitters and $K$ users; each user and transmitter caches at most $M_{\text{U}}$ and $M_{\text{T}}$ files respectively; each user cyclically communicates with $L$ transmitters. The goal is to design caching and delivery schemes to reduce the transmission latency measured by the metric normalized delivery time (NDT). By delicately designing the data placement of the transmitters and users according to the topology, we show that a combinatorial structure called multiple-antenna placement delivery array (MAPDA), which was originally proposed for the multiple-input single-output broadcast channels, can be also used to design schemes for the partially connected linear network. Then, based on existing MAPDAs and our constructing approach, we propose new schemes that achieve the optimal NDT when ${M_\text{T}}+ {M_\text{U}}\geq N$ and smaller NDT than that of the existing schemes when (${M_\text{T}}+ {M_\text{U}}\leq N$, $\frac{M_\text{U}}{N}+\frac{M_\text{T}}{N} \frac{L}{K}\left\lceil \frac{K}{L} \right\rceil \geq 1$) or (${M_\text{U}}+ {M_\text{T}}< N, \frac{K}{L}\notin\mathbb{Z}^+$). Moreover, our schemes operate in one-shot linear delivery and significantly reduce the subpacketizations compared to the existing scheme, which implies that our schemes have a wider range of applications and lower complexity of implementation.Comment: 13 page

Where there is a will, there’s a way: Job search clarity, reemployment crafting and reemployment quality

Job hunting is regarded as a self-regulatory process. However, few studies have examined the mechanism underlying the job search goal-performance relationship from the perspective of the self-regulatory behavior of reemployment crafting (RC). Therefore, the purpose of this study was to examine the mediating role of RC in the relationship between job search clarity (JSC) and reemployment quality (RQ) and the moderating role of the reemployment context. A three-wave study was conducted among 295 rural migrant workers who had experienced unemployment to successful reemployment in China. Model 4 and Model 9 from SPSS macro PROCESS were used to test the moderated mediation model. The findings indicated that (1) JSC was positively correlated with RQ; (2) seeking resources (SR) and seeking challenging demands (SCD) fully mediated the relationship between JSC and RQ; (3) supportive environment (SEn) and challenging environment (CEn), independently, have moderating effect on the relationship between JSC and SR, as well as the relationship between JSC and SCD; and (4) the mediating effect of SR as well as SCD was significant and greater when SEn and CEn were both at high levels. This study contributes to goal-setting theory and highlights the important roles of RC and the reemployment context

Kaya: A Testing Framework for Blockchain-based Decentralized Applications

In recent years, many decentralized applications based on blockchain (DApp) have been developed. However, due to inadequate testing, DApps are easily exposed to serious vulnerabilities. We find three main challenges for DApp testing, i.e., the inherent complexity of DApp, inconvenient pre-state setting, and not-so-readable logs. In this paper, we propose a testing framework named Kaya to bridge these gaps. Kaya has three main functions. Firstly, Kaya proposes DApp behavior description language (DBDL) to make writing test cases easier. Test cases written in DBDL can also be automatically executed by Kaya. Secondly, Kaya supports a flexible and convenient way for test engineers to set the blockchain pre-states easily. Thirdly, Kaya transforms incomprehensible addresses into readable variables for easy comprehension. With these functions, Kaya can help test engineers test DApps more easily. Besides, to fit the various application environments, we provide two ways for test engineers to use Kaya, i.e., UI and command-line. Our experimental case demonstrates the potential of Kaya in helping test engineers to test DApps more easily

Anàlisi de l'aplicabilitat del Blockchain a l'àmbit empresarial

[ES] El Blockchain es una de las tecnologías emergentes que cada vez está obteniendo mayor importancia debido a las características que aporta, tales como la transparencia, seguridad e inmutabilidad de los datos registrados en ello, lo que permite superar algunos de los grandes retos de los que nos afrontamos en el mundo tecnológico. Sin embargo, muchos conceptos parecen complejos de entender, por lo que existe una cierta barrera que impide que personas interesadas lleguen a entender su verdadera utilidad. Para ello, mediante este trabajo, exploramos más en detalle lo que la cadena de bloques nos puede aportar, pasando primero por sus orígenes en la criptografía, su evolución hacia las primeras redes como Bitcoin y Ethereum , así como redes alternativas que han ido surgiendo intentando subsanar los límites que ofrecen la principales redes como el problema de escalabilidad, por ejemplo mediante la red de capa 2 (Layer 2) de Polygon que ofrece mayor escalabilidad y velocidad de las transacciones gracias a su algoritmo de consenso PoS (Proof of Stake). Posteriormente nos adentramos en las distintas aplicaciones del Blockchain en los distintos sectores para investigar cómo han podido transformar dichos ámbitos mediante el uso de la tecnología de la cadena de bloques, como puede ser en el sector de las finanzas (para ofrecer un servicio de pago más eficaz), logístico (permitiendo una mejor trazabilidad), energético (mediante una distribución más eficiente de la energía), sanitario (el paciente permite quiénes pueden acceder a sus datos) o el sector público (registrando activos tanto físicos como digitales). Por último, se muestra mediante un ejemplo de uso los pasos necesarios para el despliegue de un contrato inteligente en la red de Ethereum.[EN] Blockchain is one of the emerging technologies that is becoming increasingly important due to the characteristics it brings, such as transparency, security and immutability of the data recorded in it, which allows us to overcome some of the great challenges we face in the technological world. However, many concepts seem complex to understand, so there is a certain barrier that prevents interested people from understanding their true usefulness. To do this, through this work, we explore in more detail what the blockchain can bring us, going first through its origins in cryptography, its evolution towards the first networks such as Bitcoin and Ethereum, as well as alternative networks that have been emerging trying to correct the limits offered by the main networks such as the scalability problem, for example, through Polygon¿s Layer 2 network that offers greater scalability and speed of transactions thanks to its PoS (Proof of Stake) consensus algorithm. Later we delve into the different applications of Blockchain in the different sectors to investigate how they have been able to transform these areas through the use of blockchain technology, such as in the finance sector (to offer a more effective payment service), logistics (allowing better traceability), energy (through a more efficient distribution of energy), health (the patient allows who can access their data) or the public sector (registering both physical and digital assets). Finally, an example of use shows the steps necessary for the deployment of a smart contract on the Ethereum network.Wu, Z. (2022). Análisis de la aplicabilidad del Blockchain al ámbito empresarial. Universitat Politècnica de València. http://hdl.handle.net/10251/18868