Efficacy of Entomopathogenic Fungi as Prevention against Early Life Stages of the Red Palm Weevil, Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in Laboratory and Greenhouse Trials

The red palm weevil (RPW) Rhynchophorus ferrugineus is a highly destructive invasive pest for palms whose management is mainly by application of synthetic pesticides. As a key pest of date palm plantations, it is necessary to integrate environmentally safe measures for its management. Entomopathogenic fungi (EPF) have been primarily studied as a preventative control measure due to the horizontal transfer of conidia within the RPW population. We previously demonstrated the horizontal transmission of fungal conidia from an egg-laying surface to the female weevil and then to the eggs and larvae. Based on that strategy, this study aimed to evaluate the virulence of commercial EPF products and laboratory EPF preparations to RPW females and their progeny, and their ability to protect palms against infestation. As such, it serves as a screening platform for field experiments. Mortality rates of females and eggs depended on the applied treatment formulation and fungal strain. Velifer®, a Beauveria bassiana product, and Metarhizium brunneum (Mb7) resulted in 60-88% female mortality. Mb7-as a conidial suspension or powder-resulted in 18-21% egg-hatching rates, approximately 3 times less than in the non-treated control. Treating palms with Mb7 suspension or dry formulation significantly inhibits infestation signs and results in protection. These results lay the foundation for investigating the protective rate of EPF products against RPW in date plantations.

Impact de la pandémie COVID-19 sur le suivi des patients asthmatiques

Introduction

Les deux dernières années ont été marquées par la perturbation de système sanitaire partout dans le monde à cause de la pandémie au virus SARS-CoV-2. Le suivi des patients ayants une maladie chronique dont l’asthme a été perturbé. Notre objectif est de voir l’impact de la pandémie COVID-19 sur le suivi des patients asthmatiques et leurs attitudes au cours de cette pandémie.

Méthodes

Il s’agit d’une étude descriptive, transversale menée au service de pneumo-allergologie du CHU la Rabta, durant le mois d’août 2021 intéressant les patients asthmatiques. Tous les patients ont été interrogés par téléphone sur l’impact du COVID sur leurs maladie, les données cliniques, paracliniques, le contrôle ancien de la maladie et l’observance avant la COVID ont été recueillis à partir du dossier médical.

Résultats

Quarante-quatre patients ont été recensés. L’âge moyen des patients était 49 ± 14,5 ans. Le sex-ratio femme/homme était à 2,66. Tous les patients avaient un phénotype allergique avec atopie. L’observance thérapeutique, évaluée par le score de Morisky avant la pandémie, était mauvaise dans 54,5 % avec une moyenne des exacerbations par mois de 3,05 ± 1,64 (p = 0,00). Pendant la pandémie COVID-19, les patients avaient une meilleure observance thérapeutique dans 77,3 %. Le nombre des exacerbations par mois a diminué avec une moyenne de 2,54 ± 2,12 (p = 0,00). Par contre, la COVID-19 paraît avoir un impact péjoratif sur le suivi des patients puisque seulement 45,5 % des patients ont maintenu un suivi régulier. En plus, 56,8 % des asthmatiques ont raté leurs rendez-vous pour des différentes causes. La cause la plus fréquente était la crainte de la contamination à l’hôpital dans 52,3 %. Au cours des exacerbations, 40,9 % des patients préféraient l’automédication que le recours aux urgences.

Conclusion

La pandémie à la COVID-19 a limité l’accès aux soins pour ceux ayant des pathologies chroniques. Cette situation paraît avoir un impact péjoratif sur le suivi des patients asthmatiques. Par conséquent, cela a modifié leurs attitudes devant les exacerbations.

Évolution de l’atteinte pulmonaire au scanner thoracique 6 mois après une pneumonie à COVID-19

Introduction

Certains patients gardent des symptômes plus longtemps en particulier les formes sévères de pneumonie COVID-19 mais les conséquences pulmonaires à long terme n’ont pas encore été bien élucidées. Trois mois après l’infection aiguë, un sous-ensemble de patients présente des anomalies tomodensitométriques résiduelles. Les données évolutives à 6 mois sont moins nombreuses. Le but de notre étude est d’évaluer les séquelles radiologiques à 6 mois et rechercher les facteurs qui y sont associés.

Méthodes

Il s’agit d’une cohorte de 300 patients hospitalisés entre septembre 2020 et mars 2021 pour pneumonie COVID-19, avec recueil rétrospective de données. Tous les patients ont consulté à 1 puis 3 à mois. Parmi eux, 60 patients ont bénéficié d’une TDM thoracique à 3 mois. Les patients symptomatiques ou présentant une atteinte radiologique persistante ont été revus à 6 mois. Deux groupes ont été comparés G1 et G2. G1 regroupe les patients présentant des anomalies radiologiques en faveur de fibrose pulmonaire. Les patients n’ayant pas de lésions sont inclus dans le groupe G2.

Résultats

Trois cent patients étaient revus à 3 mois, seuls 60 patients ont bénéficié d’une TDM thoracique à 3 mois montrant une atteinte interstitielle pulmonaire persistante chez 20 patients. À 6 mois, 9 patients avaient des lésions persistantes (G1). Tous les patients ont gardé une asthénie et une dyspnée d’effort (stade 3 mMRC chez 2 patients et stade 2 mMRC chez le reste). Les lésions radiologiques les plus fréquentes étaient les opacités en verre dépoli (75 %) suivies des bronchiolectasies (45 %) et épaississement septal (35 %) et distorsion scissurale (30 %) et bronchique (20 %). Comparativement à G2, G1 avaient une moyenne d’âge plus élevée (p = 0,037), une durée d’hospitalisation plus longue (p = 0,03), un score de gravité tomodensitométrique plus élevé lors de l’examen initial (sept patients ont une atteinte parenchymateuse supérieure à 75 %) et un taux plus élevé d’admission en unité de soins intensifs (6 patients) (p = 0,04). Il n’y avait pas de différence significative concernant les paramètres biologiques le taux de leucocytes, taux de lymphocytes, CRP et LDH (p > 0,05).

Conclusion

À 6 mois du suivi, certains patients garderaient les anomalies radiologiques pouvant cadrer avec fibrose pulmonaire débutante. Une atteinte initiale étendue à l’admission en soins intensifs, une longue durée d’hospitalisation seraient associées à une plus grande prévalence de séquelles pulmonaires de COVID-19.

Control of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), in Open-Field Tomatoes by Indigenous Natural Enemies Occurring in Israel

The tomato leafminer, Tuta absoluta (Meyrick), had established in Israel by 2010, attacking both open-field tomatoes and greenhouse crops.We searched for its natural enemies in open-field tomatoes, and tried to determine their potential for controlling this pest. We surveyed the local natural enemies in open tomato fields and measured their impact on pest populations in an unsprayed field. We assessed the suppressive ability of the dominant hemipteran predator, Nesidiocoris tenuis Reuter, against T. absoluta under controlled laboratory conditions and evaluated the impact of its augmentation on T. absoluta control in open-field tomatoes. We found five natural enemy species:the predator, N. tenuis, two braconids, and two eulophids. Predation accounted for 64.5±9.2% (mean ± SE) of T. absoluta larval mortality, whereas parasitism accounted for 20.96±7.5%. Together, they eliminated the pest population at tomato harvest time. Under controlled conditions, predation by N. tenuis rose from 58 to 72% with increased density of T. absoluta, suggesting positive density dependence. The reduction of T. absoluta (83%) by N. tenuis was higher than that of Bemisia tabaci (32%), suggesting a preference of N. tenuis for T. absoluta. Augmentation of N.tenuis was as effective as conventional treatment insecticide treatment, and plant damage was low and did not seem to affect yield. Results indicate that reduced pesticide use enables indigenous natural enemies, particularly N.tenuis, to successfully control T. absoluta and prevent crop damage in open-field tomatoes.

First principles calculations on nitrogen reactivity on tungsten surfaces

Using the spin-polarized gradient-corrected density functional theory we investigate the adsorption and dissociation of nitrogen molecule and hydrogen nitride radicals on two model surfaces of tungsten, W{1 0 0} and W{1 1 0}. The goal of the investigations is to predict the number and nature of the nitrogenized moieties that could be found on a tungsten surface after nitrogen-seeded hydrogen (deuterium) plasma discharge. The surfaces are considered clean or saturated in hydrogen or nitrogen atoms as they are expected to be after nitrogen seeded hydrogen plasma irradiation. We find that the radicals NH, NH2 and NH3 are dissociated by the catalytic action of the metallic surfaces if they are animated with an initial kinetic energy of less than 2.5 eV. The products of the reaction are a nitrogen atom incorporated into the metal surface and an adsorbed proton. The general conclusion is that nitrogen reduces hydrogen retention on the surface and more generally that the nitrided surfaces should be less reactive than the clean tungsten even if the two surfaces we consider behave quite differently.

Hydrogen retention in beryllium: concentration effect and nanocrystalline growth

We herein report on the formation of BeD2 nanocrystalline domes on the surface of a beryllium sample exposed to energetic deuterium ions. A polycrystalline beryllium sample was exposed to D ions at 2 keV/atom leading to laterally averaged deuterium areal densities up to 3.5 10(17) D cm(-2), and studied using nuclear reaction analysis, Raman microscopy, atomic force microscopy, optical microscopy and quantum calculations. Incorporating D in beryllium generates a tensile stress that reaches a plateau at  ≈1.5 10(17) D cm(-2). For values higher than 2.0 10(17) cm(-2), we observed the growth of  ≈90 nm high dendrites, covering up to 10% of the surface in some zones of the sample when the deuterium concentration was 3  ×  10(17) D cm(-2). These dendrites are composed of crystalline BeD2, as evidenced by Raman microscopy and quantum calculations. They are candidates to explain low temperature thermal desorption spectroscopy peaks observed when bombarding Be samples with D ions with fluencies higher than 1.2 10(17) D cm(-2).

Hydrogen retention and diffusion in tungsten beryllide

Beryllide compounds are often used in various domains because they are more resilient to oxidation than pure beryllium and at the same time they keep some of the properties of this metal. Nevertheless, the data about their properties during atomic hydrogen exposure are very scarce: numerous experiments have been conducted in the past few years on solid hydride deposition under beryllium-seeded plasma action or on energetic hydrogen implantation into metallic beryllium; many others have been devoted to hydrogen retention and diffusion in tungsten. There have been fewer studies about hydrogen interaction with the alloys of these metals, although the beryllium-tungsten mixed compounds have been experimentally detected in laboratory experiments. This article reports on calculations carried out using first-principles density functional theory (DFT) on tungsten beryllide crystal (Be12W) taken as a model alloy. The formation and reactivity of atomic vacancies are investigated in the domain of temperature ranging from 0 to 500 K, together with atomic hydrogen retention and diffusivity in the bulk and in/out vacancies.

Nitrogen reactivity toward beryllium: surface reactions

Recent experiments with nitrogen as a seeding gas in fusion plasma devices together with the option of using beryllium as an armor material in the future ITER tokamak (International Thermonuclear Experimental Reactor) have raised new interest in the interactions of beryllium surfaces with nitrogen (atomic or molecular). The strong reactivity of nitrogen implies the formation of beryllium nitrite and, in conjunction with oxygen and other possible impurities, experimentalists have to consider the probability of generating various complex moieties such as imine, amine or oxyamine, and amide radicals. This chemistry would obviously dramatically perturb the plasma, and quantum investigations can be of great predictive help. Nitrogen adsorption on beryllium basal surfaces is investigated through quantum density functional theory. Different situations are examined: molecular or atomic nitrogen reactions; nitride radical adsorption or formation on surfaces; hydrogen retention on surfaces; combined nitrogen/oxygen reactivity and hydrogen retention. A tentative comparison with experiment is also proposed.

Deuterium uptake in magnetic-fusion devices with lithium-conditioned carbon walls

Lithium wall conditioning has lowered hydrogenic recycling and dramatically improved plasma performance in many magnetic-fusion devices. In this Letter, we report quantum-classical atomistic simulations and laboratory experiments that elucidate the roles of lithium and oxygen in the uptake of hydrogen in amorphous carbon. Surprisingly, we show that lithium creates a high oxygen concentration on a carbon surface when bombarded by deuterium. Furthermore, surface oxygen, rather than lithium, plays the key role in trapping hydrogen.

Quantum modeling (DFT) and experimental investigation of beryllium-tungsten alloy formation

Beryllium, tungsten and carbon are planned as wall-cladding materials for the future international tokamak ITER. Be and W will be the dominant components and therefore the formation of binary Be-W alloys under plasma action is one of the most important issues in plasma-wall interaction processes at the first wall. This paper proposes a first-principles density functional theory (DFT) study of beryllium atom retention in tungsten, and a discussion of the results in relation to the available experimental data. In a first step, the beryllium adsorption energy is calculated on the W(100) and W(111) surfaces. Further, the activation barrier for the surface-subsurface diffusion step and subsequent bulk diffusion steps are considered. For each calculation, the electronic structure of the formed compound is analyzed through projected density of states (DOS) calculations.

Interaction of Acetic Acid with Solid Water

The interaction of acetic acid (AA, CH(3)COOH), with solid water, deposited on metals, tungsten and gold, at 80 K, was investigated. We have prepared acid/water interfaces at 80 K, namely, acid layers on thin films of solid water and H(2)O adlayers on thin acid films; they were annealed between 80 and 200 K. Metastable impact electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy UPS(HeII) were utilized to obtain information on the electronic structure of the outermost surface from the study of the electron emission from the weakest bound MOs of the acids, and of the molecular water. Temperature-programmed desorption (TPD) provided information on the desorption kinetics, and Fourier-transformed infrared spectroscopy (FTIR) provided information on the identification of the adsorbed species as well as on the water and acid crystallization. The results are compatible with the finding of ref 1 (preceding paper), made on the basis of DFT calculations, that AA adsorbs on ice as cyclic dimers. Above 120 K, a rearrangement of the AA dimers is suggested by a sharpening of the spectral features in the IR spectra and by spectral changes in MIES and UPS; this is attributed to the glass transition in AA around 130 K. Above 150 K the spectra transform into those characteristic for polycrystalline polymer chains. This structure is stable up to about 180 K; desorption of water takes place from underneath the AA film, and practically all water has desorbed through the AA film before AA desorption starts. There is no indication of water-induced deprotonation of the acid molecules. For the interaction of H(2)O molecules adsorbed on amorphous AA films, the comparison of MIES with the DFT results of ref 1 shows that the initial phase of exposure does not lead to the formation of a top-adsorbed closed water film at 80 K. Rather, the H(2)O molecules become attached to or incorporated into the preexisting AA network by H bonding; no water network is formed in the initial stage of the water adsorption. Also under these conditions no deprotonation of the acid can be detected.

Acetic Acid−Water Interaction in Solid Interfaces

The adsorption of acetic acid on a proton-ordered water ice surface is modeled using periodic plane-waves density-functional theory. The structures of acetic acid adsorbed as a monomer or oligomers, hydrated or not, are calculated through gradient optimization. The resulting quantum electronic density of states are compared to metastable impact electron spectroscopy (MIES) results and lead to selection of the most plausible structures of acetic acid on water ice. Hypotheses are formulated for the structure of the acid film growing on the ice surface including mainly cyclic dimers and hydrated forms. Adsorptions of single water molecules on acetic acid crystal surfaces are also studied after optimization of the acetic acid crystal bulk and surface structure. More comparisons with spectroscopic studies are proposed in the accompanying paper.

Hydrogen adsorption on graphite (0001) surface: A combined spectroscopy–density-functional-theory study

The adsorption of H/D atoms on the graphite (0001) surface is investigated by means of both high-resolution electron-energy loss spectroscopy (HREELS) and periodic first-principle density-functional theory. The two methods converge towards two modes of adsorption: adsorption in clusters of about four hydrogen atoms and adsorption in pairs of atoms on contiguous carbon sites. The desorption energies estimated from the calculated dissociation energies range from 8 to 185 kJ mol(-1) leading to an estimated surface coverage at saturations of 30-44 at. %. These results are compared with previous thermal desorption spectroscopy results. New HREEL signal assignments are proposed based on quantum calculations.

Interaction of formic acid with solid water

The interaction of formic acid (HCOOH) with solid water, deposited on tungsten at 80 K, was investigated. We have prepared and annealed formic acid (FA)/water interfaces (FA layers on thin films of solid water and H(2)O adlayers on thin FA films). Metastable impact electron spectroscopy and ultraviolet photoemission spectroscopy (He I and II) were utilized to study the electron emission from the 10a' to 6a' molecular orbitals (MOs) of FA, and the 1b(1), 3a(1), and 1b(2) MOs of H(2)O. These spectra were compared with results of density-functional theory calculations on FA-H(2)O complexes reported in Ref. 14 [A. Allouche, J. Chem. Phys. 122, 234703(2005), (preceding paper)]. Temperature programmed desorption was applied for information on the desorption kinetics. Initially, FA is adsorbed on top of the water film. The FA spectra are distorted with respect to those from FA monomers; it is concluded that a strong interaction exists between the adsorbates. Even though partial solvation of FA species takes place during annealing, FA remains in the top layer up to the desorption of the water film. When H(2)O molecules are offered to FA films at 80 K, no water network is formed during the initial stage of water exposure; H(2)O molecules interact individually via H bonds with the formic acid network. Experiment and theory agree that no water-induced deprotonation of the formic acid molecules takes place.

Quantum studies of hydrogen bonding in formic acid and water ice surface

The structure and spectroscopy (electronic and vibrational) of formic acid (HCOOH) dimers and trimers are investigated by means of the hybrid (B3LYP) density-functional theory. Adsorption of single and dimer HCOOH on amorphous water ice surface is modeled using two different water clusters. Particular attention has been given to spectroscopic consequences. Several hypotheses on formic acid film growing on ice and incorporation of a single water molecule in the formic acid film are proposed.

Electron delocalization by polar molecules: Interaction of Na atoms with solid ammonia films studied with MIES and density functional theory

The interaction of Na and NH(3) on tungsten was studied with metastable impact electron spectroscopy under UHV conditions. NH(3)(Na) films were grown at 90(+/-10) K on tungsten substrates and exposed to Na(NH(3)). No Na-induced reaction involving NH(3) takes place. At small Na exposures a Na-induced shift of the NH(3) spectral features is seen, in parallel with a decrease of the surface work function. At larger exposures three 3sNa-related spectral structures are seen, two of them at energetic positions different from that found for Na on metals or semiconductors. The main additional peak is attributed to delocalized Na species. A small additional feature is attributed to simultaneous ionization and excitation of partially ammoniated Na(2) species. The results are compared with density functional theory calculations which suggest that the 3sNa emission at small exposures appears to originate mainly from delocalized 3sNa electrons; they are located far from the Na species and become stabilized by solvent molecules. When depositing NH(3) molecules onto Na films, metalliclike Na patches and delocalized Na species coexist. The delocalization of 3sNa is seen up to T=130 K where the NH(3) species desorb.

Adsorption, diffusion, and recombination of hydrogen on pure and boron-doped graphite surfaces

Boron inserted as impurity by substitution of carbon atoms in graphite is known to modify the reactivity of the surface in interaction with hydrogen. Boron induces a better H retention capability in graphite while it makes easier the recombination into molecular hydrogen under heating in thermal-desorption experimental conditions. It has already been calculated that boron modifies the electronic structure of the surface, which results in an increase of the adsorption energy for H. This result seems in good agreement with the better retention for H in doped graphite, but contradictory with the easier recombination observed. The aim of this work is to dismiss this contradiction by elucidating the modifications induced by boron in the recombination mechanism. We studied the diffusion of H on pure and boron-doped graphite in the density functional theory framework. We determined a diffusionlike mechanism leading to molecular hydrogen formation. Finally, we have shown the fundamental modifications induced by boron on the [0001] graphite surface reactivity. From these calculations it stands out that recombination is the result of desorption on pure graphite and diffusion on B-doped surfaces, while the activation energy for the rate limiting step is half reduced by boron. The results are compared to experimental observations. The connection between the cluster and periodic quantum modes for graphite is also discussed.

Electron solvation by highly polar molecules: Density functional theory study of atomic sodium interaction with water, ammonia, and methanol

This study further extends the scope of a previous paper [Y. Ferro and A. Allouche, J. Chem. Phys. 118, 10461 (2003)] on the reactivity of atomic Na with water to some other highly polar molecules known for their solvation properties connected to efficient hydrogen bonding. The solvation mechanisms of ammonia and methanol are compared to the hydration mechanism. It is shown that in the case of ammonia, the stability of the solvated system is only ensured by electrostatic interactions, whereas the methanol action is more similar to that of water. More specific attention is given to the solvation process of the valence 3s Na electron. The consequences on the chemical reactivity are analyzed: Whereas ammonia is nonreactive when interacting with atomic sodium, two chemical reactions are proposed for methanol. The first process is dehydrogenation and yields methoxy species and hydrogen. The other one is dehydration and the final products are methoxy species, but also methyl radical and water. The respective roles of electron solvation and hydrogen bonds network are analyzed in detail in view of the density of states of the reactive systems.

Electron solvation by polar molecules: The interaction of Na atoms with solid methanol films studied with MIES and density functional theory calculations

The interaction of Na atoms with CH(3)OH films was studied with metastable impact electron spectroscopy (MIES) under UHV conditions. The films were grown at 90(+/-10) K on tungsten substrates and exposed to Na. Na-induced formation of methoxy (CH(3)O) species takes place, and Na atoms become ionized. At small Na exposures the outermost solvent layer remains largely intact as concluded from the absence of MIES signals caused by the reaction products. However, emission from CH(3)O, located at the film surface, occurs at larger exposures. In the same exposure range also Na species can be detected at the surface. The spectral feature from 3s Na ionization occurs at an energetic position different from that found for metals or semiconductors. The results are compared with density functional theory calculations [see Y. Ferro, A. Allouche, and V. Kempter, J. Chem. Phys. 120, 8683 (2004), preceding paper]. Experiment and theory agree in the energetic positions of the main spectral features from the methanol and sodium ionization. The calculations suggest that the 3s Na emission observed experimentally originates from solvated 3s electrons which are located far from the Na core and become stabilized by solvent molecules. The simultaneous emergence of emission from CH(3)O and from solvated 3s electrons suggests that the delocalization and, consequently, the solvation play an important role in the Na-induced formation of CH(3)O from CH(3)OH.

Cyanoacetylene adsorption on amorphous and crystalline water ice films: investigation through matrix isolation and quantum study

The structure and energy properties of the 1:1 complexes formed between cyanoacetylene and H2O (D2O) are investigated using FT-IR matrix isolation spectroscopy and ab initio calculations at the MP2/ 6-31G(d,p) level. Cyanoacetylene adsorption and desorption on amorphous ice film are monitored by FT-IR using the temperature-programmed desorption method. In an argon matrix, two types of 1:1 complexes are observed. The first one corresponds to the NH structure, which involves a hydrogen bond with the terminal nitrogen of cyanoacetylene. The second corresponds to the HO form, which involves a hydrogen bond from the cyanoacetylene to the oxygen of water. This last complex is the more stable (DeltaE = -8.1 kJ/mol.). As obtained in argon matrixes, two kinds of adsorption site are observed between HC3N and ice. The first one, stable between 25 and 45 K is characterized by a nu(OH) shift similar to the one observed in matrix for the NH complex. The second, stable at higher temperatures (between 45 and 110 K), corresponds to an interaction with the dangling oxygen site of ice and is similar to the HO complex observed in matrix. From theoretical calculations (DFT method combined with a plane wave basis set and ultrasoft pseudopotentials), it is shown that, for this adsorption site, the HC3N moiety is flattened on the ice surface and stabilized by a long-distance interaction ( approximately 3 A) between one dangling OH and the pi system of the C triple bond C triple bond. The HC3N desorption occurs between 110 and 140 K, and the associated desorption energy is 39 kJ/mol. This value is in good agreement with the first principle calculation based on density functional theory and ultrasoft pseudopotentials (34 kJ/mol). These calculations confirm the electrostatic nature of the interaction forces. A small amount of cyanoacetylene is incorporated into the bulk and desorbs at the onset of the ice crystallization near 145 K. In these two kinds of experiments, HC3N acts as both an electrophilic and a nucleophilic molecule.