Rendezvous Planning for Multiple Autonomous Underwater Vehicles using a Markov Decision Process

Multiple Autonomous Underwater Vehicles (AUVs) are a potential alternative to conventional large manned vessels for mine countermeasure (MCM) operations. Online mission planning for cooperative multi-AUV network often relies or predefined contingency on reactive methods and do not deliver an optimal end-goal performance. Markov Decision Process (MDP) is a decision-making framework that allows an optimal solution, taking into account future decision estimates, rather than having a myopic view. However, most real-world problems are too complex to be represented by this framework. We deal with the complexity problem by abstracting the MCM scenario with a reduced state and action space, yet retaining the information that defines the goal and constraints coming from the application. Another critical part of the model is the ability of the vehicles to communicate and enable a cooperative mission. We use the Rendezvous Point (RP) method. The RP schedules meeting points for the vehicles throughput the mission. Our model provides an optimal action selection solution for the multi-AUV MCM problem. The computation of the mission plan is performed in the order of minutes. This quick execution demonstrates the model is feasible for real-time applications

Optical measurements of electrophoretic suspension kinetics

Electrophoretic deposition (EPD) was originally used for formation of coatings, e. g. in the automotive industry. Recently EPD is successfully utili zed for thin film preparation with an app lication in the optics and electronics. This paper investigates the process of the suspension formation and aggregation by ultraviolet and visible spectroscopy (UV- VIS) spectroscopy and Dynamic Light Scattering (DLS) methods. The suspensions were formed by a precipitation of solution of poly[2-methoxy-5-(3 ′ ,7 ′ -dimethyloctyloxy)-1,4-phenylenevinylene] in toluene using acetonitrile as a precipitator. It could be concluded that the progressive suspension particle growth observed by DLS affects regularly the first derivative of the UV-VIS spectra. By a comparison of the results obtained by both methods it could be seen that UV-VIS spectroscopy combined with the spline method could be successfully used for an estimation of electrophoretic suspensions

Kinetic Generation of Whistler Waves in the Turbulent Magnetosheath

The Earth's magnetosheath (MSH) is governed by numerous physical processes which shape the particle velocity distributions and contribute to the heating of the plasma. Among them are whistler waves which can interact with electrons. We investigate whistler waves detected in the quasi-parallel MSH by NASA's Magnetospheric Multiscale mission. We find that the whistler waves occur even in regions that are predicted stable to wave growth by electron temperature anisotropy. Whistlers are observed in ion-scale magnetic minima and are associated with electrons having butterfly-shaped pitch-angle distributions. We investigate in detail one example and, with the support of modeling by the linear numerical dispersion solver Waves in Homogeneous, Anisotropic, Multicomponent Plasmas, we demonstrate that the butterfly distribution is unstable to the observed whistler waves. We conclude that the observed waves are generated locally. The result emphasizes the importance of considering complete 3D particle distribution functions, and not only the temperature anisotropy, when studying plasma wave instabilities.Peer reviewe

Common and distinct lateralised patterns of neural coupling during focused attention, open monitoring and loving kindness meditation

Meditation has been integrated into different therapeutic interventions. To inform the evidence-based selection of specific meditation types it is crucial to understand the neural processes associated with different meditation practices. Here we explore commonalities and differences in electroencephalographic oscillatory spatial synchronisation patterns across three important meditation types. Highly experienced meditators engaged in focused attention, open monitoring, and loving kindness meditation. Improving on previous research, our approach avoids comparisons between groups that limited previous findings, while ensuring that the meditation states are reliably established. Employing a novel measure of neural coupling – the imaginary part of EEG coherence – the study revealed that all meditation conditions displayed a common connectivity pattern that is characterised by increased connectivity of (a) broadly distributed delta networks, (b) left-hemispheric theta networks with a local integrating posterior focus, and (c) right-hemispheric alpha networks, with a local integrating parieto-occipital focus. Furthermore, each meditation state also expressed specific synchronisation patterns differentially recruiting left- or right-lateralised beta networks. These observations provide evidence that in addition to global patterns, frequency-specific inter-hemispheric asymmetry is one major feature of meditation, and that mental processes specific to each meditation type are also supported by lateralised networks from fast-frequency bands

Turbulence in Magnetic Reconnection Jets from Injection to Sub-Ion Scales

We investigate turbulence in magnetic reconnection jets in the Earth's magnetotail using data from the Magnetospheric Multiscale spacecraft. We show that fully developed turbulence is observed in many reconnection jets. The observed turbulence develops on the time scale of a few ion gyroperiods, resulting in intermittent multifractal energy cascade from the characteristic scale of the jet down to the ion scales. We show that at sub-ion scales, the fluctuations are close to mono-fractal and predominantly kinetic Alfv\'en waves. The observed energy transfer rate across the inertial range is the largest reported for space plasmas so far

Effect of treatment with enrofloxacin and Lactobacillus probiotics on ABCB1, ABCC2 and ABCG2 mRNA expression in poultry

Poultry feed is often supplemented by Lactobacillus probiotics which may alter drug bioavailability by affecting the expression of intestinal ATP-binding cassette (ABC) efflux transporters. Therefore the effect of probiotics, administered alone or in combination with enrofloxacin, on the expression of ABCB1, ABCC2 and ABCG2 mRNAs in chickens was evaluated. Day-old Ross chicks (n=24) were divided in four equal groups. Control group was not treated. The second group received feed with addition of probiotics Lactobacillus brevis, L. plantarum and L. bulgaricus 5 days after hatching, for 15 days. The third group received probiotics as described above and enrofloxacin at the age of 15 days (10 mg/kg, via drinking water for 5 days). The last group received enrofloxacin at age of 15 days (10 mg/kg, via drinking water for 5 days). Expression of ABC transporters in liver, duodenum and jejunum was determined by qRT-PCR. Down-regulation of ABCG2 mRNA in the liver (P<0.05), its up-regulation in the duodenum (P<0.05) and increased ABCB1 mRNA levels in the jejunum (P<0.05) can be attributed to enrofloxacin treatment. Decrease in ABCC2 mRNA expression in the duodenum can be associated with enrofloxacin administration. The observed changes were related to enrofloxacin administration and to lesser extent to Lactobacillus supplementation

Standard SANC modules for NLO QCD Radiative Corrections to Single-top Production

It this paper we present the results obtained with the newly created Standard SANC modules for calculation of the NLO QCD corrections to single top production processes in s and t channels at the partonic level, as well as top-decays. The main aim of these results is to prove the correct work of modules. A comprehensive comparison with results of the CompHEP system is given, where possible. These modules are intended to be used in Monte Carlo generators for single top production processes at the LHC. As in our recent paper, devoted to the electroweak corrections to these processes, we study the regularization of the top-legs associated infrared divergences with aid of the complex mass of the top quark. A comparison of QCD corrections with those computed by the conventional method is presented both for top production and decays. For s channel production we give an analytic proof of equivalence of the two methods in the limit of low top width.Comment: 21 pages, 2 figures, 17 table

Effect of the Predecessor and the Nitrogen Rate on Productivity and Essential Oil Content of Coriander (Coriandrum sativum L.) in Southeast Bulgaria

Received: May 31st, 2022 ; Accepted: August 13th, 2022 ; Published: September 19th, 2022 ; Correspondence: [email protected] (Coriandrum sativum L.) is one of the most important essential oil crops on a global scale. Coriander productivity is determined by the genotype, the environmental factors, as well the agronomic practices. A field experiment was conducted in Southeast Bulgaria during three vegetation seasons (2015, 2016, and 2017). The present study aimed at analysing the influence of two crop predecessors (winter wheat and sunflower) and four nitrogen (N) levels (0, 40, 80, and 120 kg ha-1 ). Productivity elements, seed yield, and seed essential oil content of coriander (cv. Mesten drebnoploden) were under evaluation. The results obtained showed that winter wheat was a more suitable predecessor of coriander in comparison to sunflower. The highest results regarding the number of umbels per plant, the umbel’s diameter, the number of umbellets per umbel, the number of seeds per umbel, the seed weight per plant, the 1,000 seed mass, as well as the seed yield for the rate of 80 kg ha-1 of N were recorded. The highest essential oil content after applying 120 kg ha-1 of N was established. Increasing the N level from 0 to 120 kg ha-1 led to a positive and significant effect on essential oil yield. No significant differences between the N rates of 80 and 120 kg ha-1 were recorded. The received results contributed for the evaluatation of the optimum nitrogen level, as well as for the determination of a more suitable predecessor of coriander in order to obtain the highest yield of better quality in the region of Southeast Bulgaria

Case Report of Advanced Childhood Nasopharyngeal Carcinoma: Is Radiotherapy Dose Deescalation the Right Way in Good Responders to Induction Chemotherapy

Objectives:. Treatment of childhood NPC similar to adults consists of radiotherapy and chemotherapy, but distant failure is often observed, which led to introducing the induction chemotherapy followed by radiation or chemoradiation. The improved survival rates raised the question of late toxicity. The options for lowering the toxicity rate is the application of advanced radiotherapy techniques like IMRT and VMAT, and deescalation of the radiation dose in good responders and early NPC.Case report: We report a case of13-years old male patient with a high-risk childhood undifferentiated NPC, stage cT4 cN2b M0. He presented with unilateral swallowing at the middle third of left muscle sterenocleidomastoideus, and headache, fever, sore throat and intermittent nasal bleeding for an year. Diagnostic MRI and PET/CT showed good concordance for primary tumor extension and lymph node involvement. Three coursesinduction chemotherapy were applied according to NPC2003-GPOH protocolwith good treatment response. The restaging PET/CT found no distant metastasis. Deescalated protocol of radiotherapy alone was delivered to 50.4 Gy total dose with IGRT, VMAT irradiation technique. At three month PET/CT follow up a solitary bone lesion was detected.Conclusion: The present case proved that in high risk patients more aggressive treatment strategies should be recommended with no omission of concurrent chemotherapy even after full response. Deescalation of radiotherapy dose probably is not appropriate in this group of patients. MRI and PET CT should be used as complementary imaging modalities for early detection of locoregional or distant metastasis