In an effort to identify natural bioactive compounds, three new flavonoids (1–3) and six known compounds (4–9) were isolated from the stem bark of Bougainvillea spectabilis. The structures of these ...compounds were accomplished using comprehensive spectroscopic methods, including 1D and 2D NMR spectra with references to the literatures, as well as high-resolution mass spectrometric analysis. Their cytotoxicity against KB and HeLa S-3 cell lines was also evaluated.
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Anisotropic magnetoresistive (AMR) sensors have long been used for specific industrial applications. Their field detection sensitivity can be improved using magnetic flux concentrators to amplify the ...magnetic field strength sensed at the sensor. We report on the design and fabrication of a micrometer-size meander AMR bridge sensor with an effective AMR branch length of 150. This sensor geometry has enabled us to achieve a magnetic sensitivity as high as 1.25 mV/Oe (or 0.45 mV/V/Oe), which is an enhancement by a factor of about 300 compared to conventional AMR thin film-based sensors. Our study paves a new pathway for the design and application of geomagnetic devices.
The flavor structure of quarks and leptons is not yet fully understood, but it hints a more fundamental theory of non-universal generations. We therefore propose a simple extension of the Standard ...Model by flipping (i.e., enlarging) the hypercharge \(U(1)_Y\) to \(U(1)_X\otimes U(1)_N\) for which both \(X\) and \(N\) depend on generations of both quark and lepton. By anomaly cancellation, this extension not only explains the existence of just three fermion generations as observed but also requires the presence of a right-handed neutrino per generation, which motivates seesaw neutrino mass generation. Furthermore, in its minimal version with a scalar doublet and two scalar singlets, the model naturally generates the measured fermion-mixing matrices while it successfully accommodates several flavor anomalies observed in the neutral meson mixings, \(B\)-meson decays, lepton-flavor-violating processes of charged leptons, as well as satisfying constraints from particle colliders.
Directly modeling the inherent hierarchy and shared structures of human behaviors, we present an application of the hierarchical hidden Markov model (HHMM) for the problem of activity recognition. We ...argue that to robustly model and recognize complex human activities, it is crucial to exploit both the natural hierarchical decomposition and shared semantics embedded in the movement trajectories. To this end, we propose the use of the HHMM, a rich stochastic model that has been recently extended to handle shared structures, for representing and recognizing a set of complex indoor activities. Furthermore, in the need of real-time recognition, we propose a Rao-Blackwellised particle filter (RBPF) that efficiently computes the filtering distribution at a constant time complexity for each new observation arrival. The main contributions of this paper lie in the application of the shared-structure HHMM, the estimation of the model's parameters at all levels simultaneously, and a construction of an RBPF approximate inference scheme. The experimental results in a real-world environment have confirmed our belief that directly modeling shared structures not only reduces computational cost, but also improves recognition accuracy when compared with the tree HHMM and the flat HMM.
ABSTRACT Unsustainable exploitation activities (UEAs), combined with the increasing impacts of global climate change are the key causes that lead to soil erosion in the North-Central Vietnam. ...Mountainous areas in the North-Central Vietnam commonly have steep slopes and sandy clay in the surface soil layer, which contribute to enhancing the soil erosion, resulting in a serious loss of life and property. This study investigates the land cover change (LCC) across the Thanh Chuong district by combining Remote Sensing Technique (RST) data with Geographic Information System (GIS) and further, establishing erosion risk hazard maps based on the RUSLE model simulation. To achieve these objectives, Sentinel and Landsat satellite images from the period 2010_2021 were acquired. It was verified that the forest area gradually decreased from 2010_2021, and the average annual soil loss was approximately 25 t per year. The amount of erosion that led to a soil loss of up to 18% of the total land area is related to weather conditions, terrain features, and the soil texture. The decline in the vegetation cover is expected to be the main cause of increasing trends in erosion and soil loss.
RESUMO Atividades de exploração insustentáveis (UEAs), combinadas com os crescentes impactos das mudanças climáticas globais são as principais causas que levam à erosão do solo no centro-norte do Vietnã. As áreas montanhosas no centro-norte do Vietnã geralmente têm encostas íngremes e argila arenosa na camada superficial do solo, o que contribui para aumentar a erosão do solo, resultando em uma séria perda de vidas e propriedades. Este estudo investiga a mudança de cobertura da terra (LCC) em todo o distrito de Thanh Chuong combinando dados da técnica de sensoriamento remoto (RST) com o Sistema de Informação Geográfica (GIS) e, além disso, estabelecendo mapas de risco de erosão com base na simulação do modelo RUSLE. Para atingir estes objetivos, foram adquiridas imagens dos satélites Sentinel e Landsat do período 2010-2021. Verificou-se que a área florestal diminuiu gradualmente de 2010-2021, e a perda média anual de solo foi de aproximadamente 25 t por ano. A quantidade de erosão que levou a uma perda de solo de até 18% da área total da terra está relacionada às condições climáticas, características do terreno e textura do solo. Espera-se que o declínio da cobertura vegetal seja a principal causa das tendências crescentes de erosão e perda de solo.
Blood cell‐derived extracellular vesicles (BCEVs) and lipoproteins are the major circulating nanoparticles in blood that play an important role in intercellular communication. They have attracted ...significant interest for clinical applications, given their endogenous characteristics which make them stable, biocompatible, well tolerated, and capable of permeating biological barriers efficiently. In this review, we describe the basic characteristics of BCEVs and lipoproteins and summarize their implications in both physiological and pathological processes. We also outline well accepted workflows for the isolation and characterization of these circulating nanoparticles. Importantly, we highlight the latest progress and challenges associated with the use of circulating nanoparticles as diagnostic biomarkers and therapeutic interventions in multiple diseases. We spotlight novel engineering approaches and designs to facilitate the development of these nanoparticles by enhancing their stability, targeting capability, and delivery efficiency. Therefore, the present work provides a comprehensive overview of composition, biogenesis, functions, and clinical translation of circulating nanoparticles from the bench to the bedside.
Purpose: Mekong Delta's shrimp farming contributes to socio-economic development but tends to reduce the mangrove area. On the one hand, NGOs advocate balancing ecology and economy, while on the ...other hand, the Vietnamese government supports intensifying shrimp production. The latter strategy increases shrimp diseases and marginalises smallholders. To influence the opinions, knowledge and behaviour of shrimp farmers, we developed and tested a serious board game.
Approach: Through several iterations, we designed a realistic board game mimicking local shrimp farming. Then, after conducting three sessions of gameplay with farmers in three sites, we assessed how this gameplay influenced players. We used a semi-experimental set-up by collecting data on the day of the gameplay, and on two further time-points.
Findings: After the gameplays, farmers reported to have learned about the risks of monoculture-intensive-shrimp system and the advantages of hybrid systems. Likert ratings showed that players adopted innovations faster and, in case of shrimp diseases, consulted commercial service-providers less, but with other farmers more. They confirmed to have learned that the best strategy for them would be to adopt hybrid systems, i.e. intensify part of the area of mixed-mangrove or improved-extensive shrimp farms.
Theoretical implications: Realistic board games can create opportunities for social learning and training of groups which are not always easy to reach.
Practical implications: Board games can support transfer of knowledge and skills to farmers, and can develop their critical thinking.
Creation: The findings that board games are effective in the context of a top-down extension systems offer value opportunities.
If Γ is a group, then braided Γ-crossed modules are classified by braided strict Γ-graded categorial groups. The Schreier theory obtained for Γ-module extensions of the type of an abelian Γ-crossed ...module is a generalization of the theory of Γ-module extensions.
This paper introduces a novel Gaussian process (GP) classification method that combines advantages of global and local GP approximators through a two-layer hierarchical model. The upper layer ...consists of a global sparse GP to coarsely model the entire dataset. The lower layer is a mixture of GP experts which uses local information to learn a fine-grained model. A variational inference algorithm is developed for simultaneous learning of the global GP, the experts and the gating network. Stochastic optimization can be employed for large-scale problems. Experiments on benchmark binary classification datasets demonstrate the advantages of the method in terms of scalability and classification accuracy.
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