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The properties of the magnetosheath are of pivotal importance in determining the coupling between the magnetosphere and interplanetary medium. In particular, the magnetic flux pileup and plasma depletion layer (PDL) modify the boundary conditions of magnetopause reconnection. However, the spatial distribution of the magnetic field strength and plasma density in the magnetosheath and their functional dependence on the interplanetary magnetic field (IMF) orientation remain poorly understood. This study characterizes these aspects in detail through the statistical processing of decades of data from Cluster, Double Star, THEMIS, and Magnetospheric Multiscale (MMS) missions. The first part of this study focuses on the poorly known variations across the magnetosheath, from the shock to the magnetopause. The magnetic pileup and PDL are significantly correlated, with a strong dependence on the IMF cone angle. Their dependence on the IMF clock angle is found only near the magnetopause, consistent with the expected effect of magnetic reconnection. The second part of this study examines the asymmetry in the magnetic field amplitude and density between the quasi-parallel and quasi-perpendicular sides of the equatorial magnetosheath. These asymmetries are characterized for different relative distances to the magnetopause and bow shock boundaries and for different IMF orientation. The magnetic field amplitude, observed to be higher on the quasi-perpendicular side of the magnetosheath, becomes more symmetric as it approaches the magnetopause. The quasi-parallel magnetosheath exhibits a higher plasma density near the magnetopause. However, this asymmetry reverses at approximately the mid-magnetosheath with a decreasing IMF cone angle.

Background: The prevalence of microbial infectious diseases is a major contributor to morbidity and mortality on a global scale due to the emergence of antibiotic-resistant microbes, despite the fact that many new antibiotics have been introduced for several decades. In present scenario, the potential utilization of natural plant derived extracts for medicinal and therapeutic purposes has increased remarkably due to adverse effects of synthetic drugs and resistance among pathogenic microbes. Aim of the study: Verbascum thapsus L. (Common mullein) has been traditionally used as a medicine for lung, skin and throat and many other disorders since time immemorial, therefore, the current study was aimed to evaluate the antimicrobial activity of leaf and root extracts of Verbascum thapsus against pathogenic bacterial and fungal strains and its phytochemical composition by spectral studies. Methods: Soxhlet extraction method was employed for extraction process by using varying polarity solvents like hexane, ethyl acetate and methanol. Phytochemical analysis of methanol extract was determined by Fourier Transform-Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC–MS). Antimicrobial activity was evaluated by determining the MIC and MBC/MFC of each extract by broth dilution method. Results: The antimicrobial competence of each extract sample was evaluated against six pathogenic bacterial strains and three fungal strains. Methanolic extract of leaves and the ethyl acetate extract of roots of Verbascum thapsus exhibited significant zones of inhibition against all the tested microorganisms. The highest inhibition zone was observed against the bacterial strain Bacillus subtilis (24.1±0.18 mm) followed by Streptococcus pyogenes (22.9±0.64 mm) and the fungal strain Aspergillus niger (22.8±0.55 mm) at a concentration of 500 μg/ml. Methanolic leaf extract strongly inhibited the growth of tested microbial strains with MIC ranged from 15.625 to 125 μg/ml. The FTIR and GCMS analysis confirms the presence of bioactive compound, possessing broad range of therapeutic activities. Conclusion: This Presence of various important phytoconstituents and broad-spectrum antimicrobial activity points Verbascum thapsus as a promising source for the isolations of molecules responsible for antimicrobial activities.

Every year, viticulture faces several disease outbreaks caused by pathogens with different life cycles and modes of action, and due to climate changes, the appearance of new pathogens is a concern for viticulture. To cope with the different pathogenic microorganisms, the plant must recognise the invading agent and arm itself with an arsenal of defence reactions, including the accumulation of antimicrobial metabolites. The modulation of plant metabolites is one of the first responses to biotic factors. Their rapid synthesis can greatly contribute to strengthening plant defence allowing it to adapt, minimise pathogen colonisation and survive. Despite the scientific community's efforts to characterise the grapevine defence responses to pathogens, the molecules involved in pathogen control and their specific localisation remain to be deciphered. Mass Spectrometry Imaging (MSI) analytical techniques enable one to visualise and map the spatial distribution of numerous biological molecules within plant tissues allowing a better understanding of their biosynthesis, localisation and function. In this review, we explore the applications of MSI techniques to the study of plant/microbe interactions focusing on grapevine studies. This review opens new doors to gain a comprehensive understanding of the dynamics and variations of metabolite profiles in grapevine organs, at different developmental stages and under various stress conditions. This knowledge is crucial for elucidating the role of specific metabolites in grapevine defence mechanisms, and for identifying specific regions of high or low metabolite production, which can contribute to targeted breeding to improve disease resistance traits and have an impact on grapevine productivity and quality.

The development of optical metrology suited to ultrafast lasers has played a key role in the progress of these light sources in the last few decades. Measurement techniques providing the complete E-field of ultrashort laser beams in both time and space are now being developed. Yet, they had so far not been applied to the most powerful ultrashort lasers, which reach the PetaWatt range by pushing the chirped pulse amplification (CPA) scheme to its present technical limits. This situation left doubts on their actual performance, and in particular on the peak intensity they can reach at focus. In this article we present the first complete spatio-temporal characterization of a PetaWatt femtosecond laser operating at full intensity, the BELLA laser, using two recently-developed independent measurement techniques. Our results demonstrate that, with adequate optimization, the CPA technique is still suitable at these extreme scales, i.e. it is not inherently limited by spatio-temporal couplings. We also show how these measurements provide unprecedented insight into the physics and operation regime of such laser systems.

Interactions between plants and microorganisms are complex, with some microorganisms causing damage by employing strategies that hinder plant growth and reproduction, while others positively influence plant growth through various physiological activities [...]

Salinity stress has become an increasing threat to viticulture in the Tunisian oasis, and more generally, the characterization of salinity tolerance markers can be of great interest for sustainable grape production. This study investigated some metabolic adaptations in different tissues of the ripe berries of indigenous grapevine cultivars after exposure to salt stress to identify the key traits of salt stress tolerance under oasis conditions. We especially focused on the adaptive responses occurring at the level of amino acids, polyamines, and stilbene phytoalexins in the grape berry skin, pulp, and seeds of six grapevine cultivars differing in phenotypic and ampelographic characteristics. Our data showed that amino acids accumulated strongly in the pulp and skin, while resveratrol, trans-piceid and trans-ε-viniferin, as major phytoalexins, significantly accumulated in the seeds. High salinity was also found to increase both the berry skin and pulp contents of essential amino acids such as threonine, valine, leucine, isoleucine, lysine, methionine, and phenylalanine. The amounts of stilbenes also increased under high salinity in the berry skin of all the studied cultivars. Polyamine homeostasis within the different berry tissues suggested enhanced polyamine biosynthesis rather than polyamine oxidation in response to high salinity. Our principal component analysis revealed a clear discrimination between the cultivars based on their metabolic profiles within the ripe berry tissues under high salinity.

Phytoalexins are naturally occurring molecules with antimicrobial activity deriving from the secondary metabolism of plants; they are synthesized in response to physical agents or stresses and phytopathogenic agents (fungi, bacteria and viruses), as well as numerous chemical compounds and biological control agents. Among these, grapevine phytoalexins, which belong to the chemical group of stilbenes, exhibit biocidal activity against a large number and variety of plant pathogens. It is important to investigate whether induction of stilbene phytoalexin production can serve to protect this plant against its pathogens. Quite a few chemical compounds, derivatives of phytohormones bio-elicitors as well as biocontrol agents, have been used to induce the synthesis of stilbene phytoalexins with the aim of conferring protection to grapevine against its main diseases (gray mold, downy mildew, powdery mildew and esca). This article reviews the experiments that have been carried out in this direction during the last 30 years and shows that the observed protective effects towards pathogens are generally linked to induction and priming of the grapevine phytoalexin response, confirming the interest in using, in a more general way, stimulation of the production of phytoalexins in plants as a basis for crop protection.

The main goal of this study was to investigate the effect of lead (Pb) at various concentrations, as an abiotic factor, and the cross-talk between Pb and pea aphid (Acyrthosiphon pisum (Harris)) (Hemiptera: Aphididae), as a biotic factor, on the defence responses of pea seedlings (Pisum sativum L. cv. Cysterski). The analysis of growth parameters for pea seedlings demonstrated that Pb at a low concentration, i.e., 0.025–0.0625 mM Pb(NO3)2, caused a hormesis effect, i.e., stimulation of seedling growth, whereas Pb at higher concentrations, i.e., 0.01–0.325 mM Pb(NO3)2, inhibited growth, which manifested as the inhibition of length and fresh biomass. The differences in the level of the main defence-related phytohormones, such as abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA), and indole-3-acetic acid (IAA)—an auxin stimulating plant cell growth—depended on the dose of Pb, aphid infestation and direct contact of the stress factor with the organ. A high accumulation of soluble sugars in the organs of pea seedlings both at sublethal doses and hormetic doses at early experimental time points was observed. At 0 h and 24 h of the experiment, the hormetic doses of Pb significantly stimulated invertase activities, especially in the roots. Moreover, an increase was observed in the pisatin concentration in pea seedlings growing in the presence of different concentrations of Pb and in the case of cross-talk between Pb and A. pisum in relation to the control. Additionally, a significant induction of the expressions of isoflavone synthase (IFS) and 6α-hydroxymaackiain 3-O-methyltransferase (HMM) genes, which participate in the regulation of the pisatin biosynthesis pathway, in pea seedlings growing under the influence of sublethal 0.5 mM Pb(NO3)2 and hormetic 0.075 mM Pb(NO3)2 doses of Pb was noted. The obtained results showed that the response of P. sativum seedlings depends on the Pb dose applied, direct contact of the stress factor with the organ and the duration of contact. [ABSTRACT FROM AUTHOR]

The accurate quantification of sediment mass redistribution is central to the study of surface processes, yet it remains a challenging task. Here we test a new combination of terrestrial gravity and drone photogrammetry methods to quantify sediment mass redistribution over a 1 km2 area. Gravity and photogrammetry are complementary methods. Indeed, gravity changes are sensitive to mass changes and to their location. Thus, by using photogrammetry data to constrain this location, the sediment mass can be properly estimated from the gravity data. We carried out three joint gravimetry–photogrammetry surveys, once a year in 2015, 2016 and 2017, over a 1 km2 area in southern Taiwan, featuring both a wide meander of the Laonong River and a slow landslide. We first removed the gravity changes from non-sediment effects, such as tides, groundwater, surface displacements and air pressure variations. Then, we inverted the density of the sediment with an attempt to distinguish the density of the landslide from the density of the river sediments. We eventually estimate an average loss of 3.7 ± 0.4 × 109 kg of sediment from 2015 to 2017 mostly due to the slow landslide. Although the gravity devices used in this study are expensive and need week-long surveys, new instrumentation currently being developed will enable dense and continuous measurements at lower cost, making the method that has been developed and tested in this study well-suited for the estimation of erosion, sediment transfer and deposition in landscapes.

It has been consistently demonstrated that physical exercise is a cost-effective way to promote emotional well-being. However, the environment in which it takes place might amplify or mitigate this beneficial effect. The present study aimed at comparing the effects of walking in a natural or urban field setting on positive and negative affect. For this purpose, 150 students (46 female, 104 male; mean age: 20.2 years) were randomized into one of three groups: Green Walking (GW, n = 50), Urban Walking (UW, n = 50), or no-exercise (control; CTRL, n = 50). Positive and negative affect ratings were collected for each participant before and after walking (or before and after attending a class in the CTRL group). Exercise parameters (duration, intensity, weather conditions, group size) were identical in the GW and UW groups. The walking routes differed in terms of vegetation density, proximity of water, presence of traffic, and amount of asphalted surfaces. Participants in the GW and UW groups reported significant reductions in negative affect pre- to post walking. However, positive affect was increased only for participants in the GW group. This finding may have meaningful implications for mental health professionals who treat patients with significant emotional distress or mood instability. Several explanations are discussed as potential mechanisms for the more beneficial effect of Green walking, and presented as an important avenue for future research.

A new generation of clay-based nano pigments has been introduced, providing the advantage of both inorganic pigments and organic dyes. These nano pigments have been synthesized through a stepwise procedure where, initially, an organic dye is adsorbed onto the surface of the adsorbent, and then dye adsorbed adsorbent is used as pigment for further applications. The objective of the current paper was to examine the interaction of non-biodegradable toxic dyes, Crystal Violet (CV) and Indigo Carmine (IC), with clay minerals (montmorillonite (Mt), vermiculite (Vt), and clay bentonite (Bent)) and their organically modified forms (OMt, OBent, and OVt) and to develop a novel methodology for the synthesis of the value-added products and clay-based nano pigments without creating second generation waste materials. In our observation, the uptake of CV was more intense onto pristine Mt, Bent, and Vt, and the uptake of IC was more onto OMt, OBent, and OVt. CV was found to be in the interlayer region of Mt and Bent, as supported by XRD data. Zeta potential values confirmed the presence of CV on their surface. In contrast, in the case of Vt and organically modified forms, the dye was found on the surface, confirmed by XRD and zeta potential values. In the case of indigo carmine, the dye was found only on the surface of pristine Mt, Bent, Vt, and organo Mt, Bent, Vt. During the interaction of CV and IC with clay and organoclays, intense violet and blue-colored solid residues were obtained (also known as clay-based nano pigments). The nano pigments were used as colorants in a poly (methyl-methacrylate) (PMMA) polymer matrix to form transparent polymer films.