Enhancement of in vitro production of volatile organic compounds by shoot differentiation in Artemisia spicigera

Callus initiation, shoot formation and plant regeneration were established for Artemisia spicigera, a traditional medicinal plant growing in Armenia, Middle-Anatolia and Iran, and pro- ducing valuable volatile organic compounds (VOCs) that are mostly represented by monoterpe- noids. Optimal callus initiation and shoot production were obtained by culture of hypocotyl and cotyledon explants on MS medium comprising 0.5 mg L−1 naphthalene acetic acid (NAA) and 0.5 mg L−1 6-benzyladenine (BA). Consequently, the shoots were transferred onto the MS media sup- plemented with 1 mg L−1 of indole-3-butyric acid (IBA) or 1 mg L−1 of NAA. Both types of auxin induced root formation on the shoots and the resulting plantlets were successfully grown in pots. The production of VOCs in callus tissues and regenerated plantlets was studied by gas chroma- tography–mass spectrometry (GC-MS) analysis. Although the potential of undifferentiated callus to produce VOCs was very low, an increased content of bioactive volatile components was ob- served at the beginning of shoot primordia differentiation. Intriguingly, the volatiles obtained from in vitro plantlets showed quantitative and qualitative variation depending on the type of auxins used for the rooting process. The acquired quantities based on total ion current (TIC) showed that the regenerated plantlets using 1 mg L−1 NAA produced higher amounts of oxygenated monoter- penes such as camphor (30.29%), cis-thujone (7.07%), and 1,8-cineole (6.71%) and sesquiterpene derivatives, namely germacrene D (8.75%), bicyclogermacrene (4.0%) and spathulenol (1.49%) compared with the intact plant. According to these findings, in vitro generation of volatile organic compounds in A. spicigera depends on the developmental stages of tissues and may enhance with the formation of shoot primordia and regeneration of plantlets

Many-electron tunneling in atoms

A theoretical derivation is given for the formula describing N-electron ionization of atom by a dc field and laser radiation in tunneling regime. Numerical examples are presented for noble gases atoms.Comment: 11 pages, 1 EPS figure, submitted to JETP (Jan 99

Self-consistent modeling of the energetic storm particle event of November 10, 2012

It is thought that solar energetic ions associated with coronal/interplanetary shock waves are accelerated to high energies by the diffusive shock acceleration mechanism. For this mechanism to be efficient, intense magnetic turbulence is needed in the vicinity of the shock. The enhanced turbulence upstream of the shock can be produced self-consistently by the accelerated particles themselves via streaming instability. Comparisons of quasi-linear-theory-based particle acceleration models that include this process with observations have not been fully successful so far, which has motivated the development of acceleration models of a different nature. The aim of this work is to test how well our self-consistent quasi-linear SOLar Particle Acceleration in Coronal Shocks (SOLPACS) simulation code, developed earlier to simulate proton acceleration in coronal shocks, models the particle foreshock region. We applied SOLPACS to model the energetic storm particle (ESP) event observed by the STEREO A spacecraft on November 10, 2012. In the simulations, all but one main input parameter of SOLPACS are fixed by the in-situ plasma measurements from the spacecraft. By comparing a simulated proton energy spectrum at the shock with the observed one, we were able to fix the last simulation input parameter related to the efficiency of particle injection to the acceleration process. A subsequent comparison of simulated proton time-intensity profiles in a number of energy channels with the observed ones shows a very good correspondence throughout the upstream region

Shapes of leading tunnelling trajectories for single-electron molecular ionization

Based on the geometrical approach to tunnelling by P.D. Hislop and I.M. Sigal [Memoir. AMS 78, No. 399 (1989)], we introduce the concept of a leading tunnelling trajectory. It is then proven that leading tunnelling trajectories for single-active-electron models of molecular tunnelling ionization (i.e., theories where a molecular potential is modelled by a single-electron multi-centre potential) are linear in the case of short range interactions and "almost" linear in the case of long range interactions. The results are presented on both the formal and physically intuitive levels. Physical implications of the obtained results are discussed.Comment: 14 pages, 5 figure

On negative higher-order Kerr effect and filamentation

As a contribution to the ongoing controversy about the role of higher-order Kerr effect (HOKE) in laser filamentation, we first provide thorough details about the protocol that has been employed to infer the HOKE indices from the experiment. Next, we discuss potential sources of artifact in the experimental measurements of these terms and show that neither the value of the observed birefringence, nor its inversion, nor the intensity at which it is observed, appear to be flawed. Furthermore, we argue that, independently on our values, the principle of including HOKE is straightforward. Due to the different temporal and spectral dynamics, the respective efficiency of defocusing by the plasma and by the HOKE is expected to depend substantially on both incident wavelength and pulse duration. The discussion should therefore focus on defining the conditions where each filamentation regime dominates.Comment: 22 pages, 11 figures. Submitted to Laser physics as proceedings of the Laser Physics 2010 conferenc

Orientation dependence of high-order harmonic generation in molecules

Published versio

Patient Selection in One Anastomosis/Mini Gastric Bypass—an Expert Modified Delphi Consensus

Purpose: One anastomosis/mini gastric bypass (OAGB/MGB) is up to date the third most performed obesity and metabolic procedure worldwide, which recently has been endorsed by ASMBS. The main criticisms are the risk of bile reflux, esophageal cancer, and malnutrition. Although IFSO has recognized this procedure, guidance is needed regarding selection criteria. To give clinicians a daily support in performing the right patient selection in OAGB/MGB, the aim of this paper is to generate clinical guidelines based on an expert modified Delphi consensus. Methods: A committee of 57 recognized bariatric surgeons from 24 countries created 69 statements. Modified Delphi consensus voting was performed in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was considered to indicate a consensus. Results: Consensus was achieved for 56 statements. Remarkably, ≥ 90.0% of the experts felt that OAGB/MGB is an acceptable and suitable option "in patients with Body mass index (BMI) > 70, BMI > 60, BMI > 50 kg/m2 as a one-stage procedure," "as the second stage of a two-stage bariatric surgery after Sleeve Gastrectomy for BMI > 50 kg/m2 (instead of BPD/DS)," and "in patients with weight regain after restrictive procedures. No consensus was reached on the statement that OAGB/MGB is a suitable option in case of resistant Helicobacter pylori. This is likely as there is a concern that this procedure is associated with reflux and its related long-term complications including risk of cancer in the esophagus or stomach. Also no consensus reached on OAGB/MGB as conversional surgery in patients with GERD after restrictive procedures. Consensus for disagreement was predominantly achieved "in case of intestinal metaplasia of the stomach" (74.55%), "in patients with severe Gastro Esophageal Reflux Disease (GERD)(C,D)" (75.44%), "in patients with Barrett's metaplasia" (89.29%), and "in documented insulinoma" (89.47%). Conclusion: Patient selection in OAGB/MGB is still a point of discussion among experts. There was consensus that OAGB/MGB is a suitable option in elderly patients, patients with low BMI (30-35 kg/m2) with associated metabolic problems, and patients with BMIs more than 50 kg/m2 as one-stage procedure. OAGB/MGB can also be a safe procedure in vegetarian and vegan patients. Although OAGB/MGB can be a suitable procedure in patients with large hiatal hernia with concurrent hiatal hernia, it should not be offered to patients with grade C or D esophagitis or Barrett's metaplasia.info:eu-repo/semantics/publishedVersio

Feedback control algorithms for the dissipation of traffic waves with autonomous vehicles

International audienceThis article considers the problem of traffic control in which an autonomous vehicle is used to regulate human piloted traffic to dissipate stop and go traffic waves. We first investigate the controllability of well-known microscopic traffic flow models, namely i) the Bando model (also known as the optimal velocity model), ii) the follow-the-leader model, and iii) a combined optimal velocity follow the leader model. Based on the controllability results, we propose three control strategies for an autonomous vehicle to stabilize the other, human-piloted traffic. We subsequently simulate the control effects on the microscopic models of human drivers in numerical experiments to quantify the potential benefits of the controllers. Based on the simulations, finally we conduct a field experiment with 22 human drivers and a fully autonomous-capable vehicle, to assess the feasibility of autonomous vehicle based traffic control on real human piloted traffic. We show that both in simulation and in the field test that an autonomous vehicle is able to dampen waves generated by 22 cars, and that as a consequence, the total fuel consumption of all vehicles is reduced by up to 20%