Direct Simulations of Wind-Driven Breaking Ocean Waves with Data Assimilation

A formulation is developed to assimilate ocean-wave data into the Numerical Flow Analysis (NFA) code. NFA is a Cartesian-based implicit Large-Eddy Simulation (LES) code with Volume of Fluid (VOF) interface capturing. The sequential assimilation of data into NFA permits detailed analysis of ocean-wave physics with higher bandwidths than is possible using either other formulations, such as High-Order Spectral (HOS) methods, or field measurements. A framework is provided for assimilating the wavy and vortical portions of the flow. Nudging is used to assimilate wave data at low wavenumbers, and the wave data at high wavenumbers form naturally through nonlinear interactions, wave breaking, and wind forcing. Similarly, the vertical profiles of the mean vortical flow in the wind and the wind drift are nudged, and the turbulent fluctuations are allowed to form naturally. As a demonstration, the results of a HOS of a JONSWAP wave spectrum are assimilated to study short-crested seas in equilibrium with the wind. Log profiles are assimilated for the mean wind and the mean wind drift. The results of the data assimilations are (1) Windrows form under the action of breaking waves and the formation of swirling jets; (2) The crosswind and cross drift meander; (3) Swirling jets are organized into Langmuir cells in the upper oceanic boundary layer; (4) Swirling jets are organized into wind streaks in the lower atmospheric boundary layer; (5) The length and time scales of the Langmuir cells and the wind streaks increase away from the free surface; (6) Wave growth is very dynamic especially for breaking waves; (7) The effects of the turbulent fluctuations in the upper ocean on wave growth need to be considered together with the turbulent fluctuations in the lower atmosphere; and (8) Extreme events are most likely when waves are not in equilibrium.Comment: 46 pages, 30th Symposium on Naval Hydrodynamics, Hobart, Tasmania, Australia, 2-7 November 201

Интеллектуальная радиосеть с нечеткой конфигурацией

В статье обсуждаются возможности применения одноранговой радиосети стандарта IEEE 802.15.4 (ZigBee) диапазона 2,4 ГГц для работы системы, состоящей из группы малогабаритных мобильных роботов и одного командного пункта. Основная задача группы роботов – проведение разведки во время спасательных операций после техногенных и природных катастроф и аварий. Для сохранения управляемости отдельными роботами и системой в целом предлагается повысить «интеллект» системы связи за счет гибкой маршрутизации каналов между командным пунктом и конкретным мобильным роботом с тем, чтобы иметь систему с автоматическим, интеллектуальным восстановлением канала обмена данных.У статті обговорюються можливості застосування однорангової радіомережі стандарту ІЕЕ 802.15.4 (ZigBee) діапазону 2,4 Ггу для роботи системи, що складається з групи малогабаритних мобільних роботів та одного командного пункту. Основна задача групи роботів – проведення розвідки під час рятувальних операцій після техногенних та природних катастроф і аварій. Для збереження керованості окремими ротами та системою в цілому пропонується підвищити інтелект системи зв’язку за рахунок гнучкої маршрутитизації каналів між командним пунктом та конкретним мобільним роботом з тим, щоб мати систему з автоматичним, інтелектуальним відновлюванням каналу обміну даних.In the article the possibilities of application peer-to-peer radio networks of standard IEEE 802.15.4 (ZigBee) a range of 2,4 GHz for work of the system consisting of small-sized mobile robots group and one command point are discussed. The primary goal of group of robots – is carrying out of investigation during rescue operations after technogenic and natural accidents and failures. For controllability preservation by separate robots and system as a whole, it is offered to raise “intelligence” of a communication system at the expense of flexible routeing of channels between command point and the concrete mobile robot to have system with automatic, intellectual restoration of the channel of data exchange

User Selection Approaches to Mitigate the Straggler Effect for Federated Learning on Cell-Free Massive MIMO Networks

This work proposes UE selection approaches to mitigate the straggler effect for federated learning (FL) on cell-free massive multiple-input multiple-output networks. To show how these approaches work, we consider a general FL framework with UE sampling, and aim to minimize the FL training time in this framework. Here, training updates are (S1) broadcast to all the selected UEs from a central server, (S2) computed at the UEs sampled from the selected UE set, and (S3) sent back to the central server. The first approach mitigates the straggler effect in both Steps (S1) and (S3), while the second approach only Step (S3). Two optimization problems are then formulated to jointly optimize UE selection, transmit power and data rate. These mixed-integer mixed-timescale stochastic nonconvex problems capture the complex interactions among the training time, the straggler effect, and UE selection. By employing the online successive convex approximation approach, we develop a novel algorithm to solve the formulated problems with proven convergence to the neighbourhood of their stationary points. Numerical results confirm that our UE selection designs significantly reduce the training time over baseline approaches, especially in the networks that experience serious straggler effects due to the moderately low density of access points.Comment: submitted for peer review

A Multidomain Intervention Program for Older People with Dementia: A Pilot Study

Background: Multidomain interventions have been shown to be effective in improving cognition, quality of life, reducing neuropsychiatric symptoms and delaying progression of functional impairment or disability in dementia patients. To investigate the multidomain intervention in other populations and diverse cultural and geographical settings, this pilot study will assess the feasibility of a multidomain intervention for older people with dementia in nursing homes in Vietnam. Methods: Participants will be randomized into two equal groups, to receive either a multidomain intervention (intervention group) or regular health advice (control group). The intervention will include physical, cognitive, and social interventions as well as management of metabolic and vascular risk factors. We will hypothesize that the multidomain intervention will be feasible in Vietnam, and participants who receive the intervention will show improvement in quality of life, behaviors, functional ability, cognitive function, sleep, and in reduction of falls, use of healthcare services, and death rate compared to those in the control group during the 6 months intervention period and after the 6 months extended follow-up. Discussion: This is the first study to evaluate the feasibility of a multidomain intervention program for older people with dementia in nursing homes in Vietnam. The results from the trial will inform clinicians and the public of the possibility of comprehensive treatment beyond simply drug treatments for dementia. This paves the way for further studies to evaluate the long-term effects of multidomain interventions in dementia patients. Furthermore, the research results will provide information on the effectiveness of multidomain interventions which will inform policy development on dementia. Trial Registration: The trial is registered with ClinicalTrials.gov identifier: NCT04948450 on 02/07/2021

Isolation and characterization of novel microsatellite markers and their application for diversity assessment in cultivated groundnut (Arachis hypogaea)

<p>Abstract</p> <p>Background</p> <p>Cultivated peanut or groundnut (<it>Arachis hypogaea </it>L.) is the fourth most important oilseed crop in the world, grown mainly in tropical, subtropical and warm temperate climates. Due to its origin through a single and recent polyploidization event, followed by successive selection during breeding efforts, cultivated groundnut has a limited genetic background. In such species, microsatellite or simple sequence repeat (SSR) markers are very informative and useful for breeding applications. The low level of polymorphism in cultivated germplasm, however, warrants a need of larger number of polymorphic microsatellite markers for cultivated groundnut.</p> <p>Results</p> <p>A microsatellite-enriched library was constructed from the genotype TMV2. Sequencing of 720 putative SSR-positive clones from a total of 3,072 provided 490 SSRs. 71.2% of these SSRs were perfect type, 13.1% were imperfect and 15.7% were compound. Among these SSRs, the GT/CA repeat motifs were the most common (37.6%) followed by GA/CT repeat motifs (25.9%). The primer pairs could be designed for a total of 170 SSRs and were optimized initially on two genotypes. 104 (61.2%) primer pairs yielded scorable amplicon and 46 (44.2%) primers showed polymorphism among 32 cultivated groundnut genotypes. The polymorphic SSR markers detected 2 to 5 alleles with an average of 2.44 per locus. The polymorphic information content (PIC) value for these markers varied from 0.12 to 0.75 with an average of 0.46. Based on 112 alleles obtained by 46 markers, a phenogram was constructed to understand the relationships among the 32 genotypes. Majority of the genotypes representing subspecies <it>hypogaea </it>were grouped together in one cluster, while the genotypes belonging to subspecies <it>fastigiata </it>were grouped mainly under two clusters.</p> <p>Conclusion</p> <p>Newly developed set of 104 markers extends the repertoire of SSR markers for cultivated groundnut. These markers showed a good level of PIC value in cultivated germplasm and therefore would be very useful for germplasm analysis, linkage mapping, diversity studies and phylogenetic relationships in cultivated groundnut as well as related <it>Arachis </it>species.</p

. In vitro propagation of the new orchid Dendrobium trankimianum T. Yukawa

Dendrobium trankimianum T. Yukawa is a beautiful, endemic orchid of Vietnam, a new species with a first - published description in 2004. It is very rare and expected to be added to the IUCN Red List status - CR. In vitro studies of orchid D. trankimianum T. Yukawa were conducted in order to conserve and increase the genetic pool of this precious wild orchid species. The results showed that full-strength MS medium supplemented with 2.0 mg/L BA and 0.5 mg/L NAA (10.24 PLBs/explant; 90.11% explants formed PLBs) or full-strength MS medium supplemented with 1.5 mg/L TDZ and 0.5 mg/L NAA (14.11 PLBs/explant; 92.06% explants formed PLBs) were the most suitable for protocorm formation. For subculture, suitable growth of shoots were obtained on full-strength MS medium supplemented 1.5 mg/L BA (22.35 shoots/explant; shoots length of 1.96 cm) and full-strength MS medium supplemented with 60 g ripe banana per liter (25.11 shoots/explant; shoots length of 2.12 cm). The shoots in vitro were transferred to half-strength MS supplemented with different concentrations of IAA, IBA and NAA to investigate root formation. The best rooting occurred at 0,5 mg/L NAA (7.91 roots/shoot; root length of 4.01 cm; 98.51% root formation). The plantlets with uniform growth were planted on different substrate: Eco clean soil, Coconut fiber, Fern fiber, 50% Rice husk in combination with 50% Eco clean soil for research the most suitable substrate. After 60 days of transplantion and acclimatization, the result showed that Fern fiber was suitable substrate for plantlet growth in a nursery garden (8.0 roots/ explant; root length of 5.5 cm; survival rate of 93.29%)

Impact of various essential oils and plant extracts on the characterization of the composite seaweed hydrocolloid and gac pulp (Momordica cochinchinensis) edible film

Edible films and coatings have currently received increasing interest because of their potential in food applications. This study examined the effect of incorporated essential oils and natural plant extracts on the characteristics of the composite seaweed hydrocolloid and gac pulp films. Films were prepared by a casting technique, followed by measurement of physical, optical, barrier, mechanical, and structural properties. The results showed that adding plant oils and extracts significantly affected the physical, optical, mechanical, and structural properties of the composite films. Incorporation of the essential oils resulted in a reduction in moisture content and opacity while increasing values for Hue angle and elongation at break of the composite films. Besides, incorporation of the plant extracts showed increases in thickness, opacity, Delta E, Chroma, and elongation at the break, while there is a decrease in the Hue angle values of the composite films. In conclusion, incorporating plant essential oils and extracts into composite seaweed hydrocolloid and gac pulp films can enhance film properties, which can potentially be applied in food products