Compatibility of mycorrhiza-induced resistance with viral and bacterial entomopathogens in the control of Spodoptera exigua in tomato.

BACKGROUND: Arbuscular mycorrhizal fungi (AMF) are soil-borne microorganisms that establish mutualistic associations with roots of most terrestrial plants. This symbiosis results in nutritional and defensive benefits to the host plant, usually conferring protection against biotic stresses, but its indirect impact on third trophic levels is still unknown. In the present work, we explore whether the symbiosis of tomato plants with Funneliformis mosseae (and/or exposition to herbivory) influences the interaction of the generalist pest Spodoptera exigua (Lepidoptera: Noctuidae) with bacterial (Bacillus thuringiensis) and viral (baculovirus, SeMNPV) natural entomopathogens. RESULTS: Symbiosis with AMF and previous herbivory reduces the relative growth of S. exigua, increases its susceptibility to a sublethal dose of B. thuringiensis and has positive or neutral impact on the lethality of SeMNPV. Reduction of the phenoloxidase activity, a marker of the insect immune response, was associated with the larval feeding on plant material previously exposed to herbivory but not to the AMF. In addition, no changes in the insect gut microbiota could be associated with the observed changes in larval growth and susceptibility to the entomopathogens. CONCLUSION: Our findings provide the first evidence of compatibility of AMF symbiosis in tomato with the use of bacterial and viral entomopathogens, contributing to the development of novel approaches to combine the beneficial effect of AMF and entomopathogens in biological pest control. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Expanding the Medfly Virome: Viral Diversity, Prevalence, and sRNA Profiling in Mass-Reared and Field-Derived Medflies.

The Mediterranean fruit fly (medfly), Ceratitis capitata, is an agricultural pest of a wide range of fruits. The advent of high-throughput sequencing has boosted the discovery of RNA viruses infecting insects. In this article, we aim to characterize the RNA virome and viral sRNA profile of medfly. By means of transcriptome mining, we expanded the medfly RNA virome to 13 viruses, including two novel positive ssRNA viruses and the first two novel dsRNA viruses reported for medfly. Our analysis across multiple laboratory-reared and field-collected medfly samples showed the presence of a core RNA virome comprised of Ceratitis capitata iflavirus 2 and Ceratitis capitata negev-like virus 1. Furthermore, field-collected flies showed a higher viral diversity in comparison to the laboratory-reared flies. Based on the small RNA sequencing, we detected small interfering RNAs mapping to all the viruses present in each sample, except for Ceratitis capitata nora virus. Although the identified RNA viruses do not cause obvious symptoms in medflies, the outcome of their interaction may still influence the medfly's fitness and ecology, becoming either a risk or an opportunity for mass-rearing and SIT applications.

A proctolin-like peptide is regulated after baculovirus infection and mediates in caterpillar locomotion and digestion.

Baculoviruses constitute a large group of invertebrate DNA viruses, predominantly infecting larvae of the insect order Lepidoptera. During a baculovirus infection, the virus spreads throughout the insect body producing a systemic infection in multiple larval tissues, included the central nervous system (CNS). As a main component of the CNS, neuropeptides are small protein-like molecules functioning as neurohormones, neurotransmitters, or neuromodulators. These peptides are involved in regulating animal physiology and behavior and could be altered after baculovirus infection. In this study, we have investigated the effect of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) infection on expression of Spodoptera exigua neuropeptides and neuropeptide-like genes. Expression of the gene encoding a polypeptide that resembles the well-known insect neuropeptide proctolin and named as proctolin-like peptide (PLP), was downregulated in the larval brain following infection and was chosen for further analysis. A recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) overexpressing the C-terminal part of the PLP was generated and used in bioassays using S. exigua larvae to study its influence on the viral infection and insect behavior. AcMNPV-PLP-infected larvae showed less locomotion activity and a reduction in growth compared to larvae infected with wild type AcMNPV or mock-infected larvae. These results are indicative of this new peptide as a neuromodulator that regulates visceral and skeletal muscle contractions and offers a novel effector involved in the behavioral changes during baculovirus infection.

Preservation of anti-SARS-CoV-2 neutralising antibodies in convalescent plasma after pathogen reduction with methylene blue and visible light.

BACKGROUND: COVID-19 convalescent plasma (CCP) is an experimental treatment against SARS-CoV-2. Although there has so far been no evidence of transmission through transfusion, pathogen reduction technologies (PRT) have been applied to CCP to mitigate risk of infectious disease. This study aims to assess the impact of methylene blue (MB) plus visible light PRT on the virus-neutralising activity of the specific antibodies against SARS-CoV-2. MATERIAL AND METHODS: Thirty-five plasma doses collected by plasmapheresis from COVID-19 convalescent donors were subjected to MB plus visible light PRT. Anti-SARS-CoV-2 RBD S1 epitope IgGs antibodies were quantified by ELISA. Titres of SARS-CoV-2 neutralising antibodies (NtAbs) were measured before and after the PRT process. A Spearman's correlation was run to determine the relationship between antibody neutralisation ability and SARS-CoV-2 IgG ELISA ratio. Pre- and post-inactivation neutralising antibody titres were evaluated using a Wilcoxon test. RESULTS: The plasma pathogen reduction procedure did not diminish NtAbS titres and so did not cause a change in the viral neutralisation capacity of CCP. There was a strong correlation between pre-and post-PRT NtAbs and anti-SARS-CoV-2 IgGs titres. DISCUSSION: Our results showed PRT with MB did not impair the CCP passive immunity preserving its potential therapeutic potency. Therefore, PRT of CCP should be recommended to mitigate the risk for transmission of transfusion-associated infectious disease. There is a good correlation between SARS-CoV-2 IgG titres determined by ELISA and the neutralising capacity. This allows blood centres to select CCP donors based on IgG ELISA titres avoiding the much more labour-intensive laboratory processes for determining neutralising antibodies.

Baculovirus infection affects caterpillar chemoperception.

Baculoviruses are double-stranded DNA entomopathogenic viruses that infect predominantly insects of the order Lepidoptera. Research in the last decade has started to disentangle the mechanisms underlying the insect-virus interaction, particularly focusing on the effects of the baculovirus infection in the host's physiology. Among crucial physiological functions, olfaction has a key role in reproductive tasks, food source detection and enemy avoidance. In this work, we describe that Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) induces expression changes in some odorant receptors (ORs) - the centrepiece of insect's olfaction - when infecting larvae from its natural host Spodoptera exigua (Lepidoptera: Noctuidae). Different ORs are up-regulated in larvae after SeMNPV infection, and two of them, SexiOR35 and SexiOR23, were selected for further functional characterization by heterologous expression in empty neurons of Drosophila melanogaster coupled to single-sensillum recordings. SexiOR35 appears to be a broadly tuned receptor able to recognise multiple and different chemical compounds. SexiOR23, although correctly expressed in Drosophila neurons, did not display any significant response to a panel of 58 stimuli. Behavioural experiments revealed that larvae infected by SeMNPV exhibit altered olfactory-driven behaviour to diet when it is supplemented with the plant volatiles linalool or estragole, two of the main SexiOR35 ligands, supporting the hypothesis that viral infection triggers changes in host perception through changes in the expression level of specific ORs.

Mycorrhizal symbiosis primes the accumulation of antiherbivore compounds and enhances herbivore mortality in tomato.

Plant association with arbuscular mycorrhizal fungi (AMF) can increase their ability to overcome multiple stresses, but their impact on plant interactions with herbivorous insects is controversial. Here we show higher mortality of the leaf-chewer Spodoptera exigua when fed on tomato plants colonized by the AMF Funneliformis mosseae, evidencing mycorrhiza-induced resistance. In search of the underlying mechanisms, an untargeted metabolomic analysis through ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS) was performed. The results showed that mycorrhizal symbiosis had a very limited impact on the leaf metabolome in the absence of stress, but significantly modulated the response to herbivory in the damaged area. A cluster of over accumulated metabolites was identified in those leaflets damaged by S. exigua feeding in mycorrhizal plants, while unwounded distal leaflets responded similar to those from non-mycorrhizal plants. These primed-compounds were mostly related to alkaloids, fatty acid derivatives and phenylpropanoid-polyamine conjugates. The deleterious effect on larval survival of some of these compounds, including the alkaloid physostigmine, the fatty acid derivatives 4-oxododecanedioic acid and azelaic acid, was confirmed. Thus, our results evidence the impact of AMF on metabolic reprograming upon herbivory that leads to a primed accumulation of defensive compounds.

Flow ventricular catheters for shunted hydrocephalus: initial clinical results.

BACKGROUND: The non-homogenous flow of the cerebrospinal fluid within the ventricular catheter is one of the causative factors in shunt obstructions during the treatment of hydrocephalus. Previously, we studied the flow in ventricular catheters under the steady and pulsatile boundary conditions by means of computational fluid dynamics (CFD) in three-dimensional paradigms. Subsequently, several catheter designs with homogeneous flow patterns were developed out of which one prototype was chosen after a validation study. OBJECTIVE: To test the effectiveness of the flow ventricular catheter in a prospective, multicenter, comparative study. METHODS: Eligible centers were three pediatric hospitals: two with sole adult practice and one a mixed pediatric-adult. Standard silicone material was used to develop a parametric catheter model with homogenous flow characteristics. The flow catheters were inserted in pediatric (n = 30) and adult (n = 10) patients with all types of hydrocephalus. Simultaneously, regular ventricular catheters were inserted in another 43 control patients in the participating centers. Catheter positioning was standardized according to the Schaumann and Thomale classification. RESULTS: All ventricular catheters had a cephalad grade I or II positioning, and caudally, its extension had a peritoneal location. Programmable valves were utilized in 70% and antisiphon devices in 20% of the cases. Regular differential pressure valves were utilized in the remaining. No case of flow catheter obstruction was identified during a mean follow-up period of 2 years at the time of this writing. There were four catheter obstructions in the control cohort, all pediatric cases, during the first year. Shunt infections occurred in two cases in the control group, while there was one recurrent case of adult ventriculitis in the flow catheter group. CONCLUSIONS: This prototype model represents the next generation of ventricular catheters with a homogeneous flow pattern. The flow catheter can be inserted safely in hydrocephalic patients, and this preliminary prospective comparative study showed a possible obstruction-free functionality.

Entropy Monotonicity and Superstable Cycles for the Quadratic Family Revisited.

The main result of this paper is a proof using real analysis of the monotonicity of the topological entropy for the family of quadratic maps, sometimes called Milnor's Monotonicity Conjecture. In contrast, the existing proofs rely in one way or another on complex analysis. Our proof is based on tools and algorithms previously developed by the authors and collaborators to compute the topological entropy of multimodal maps. Specifically, we use the number of transverse intersections of the map iterations with the so-called critical line. The approach is technically simple and geometrical. The same approach is also used to briefly revisit the superstable cycles of the quadratic maps, since both topics are closely related.

Coupling Transcriptomics and Behaviour to Unveil the Olfactory System of Spodoptera exigua Larvae.

Insect chemosensation is crucial for many aspects related to food seeking, enemy avoidance, and reproduction. Different families of receptors and binding proteins interact with chemical stimuli, including odorant receptors (ORs), ionotropic receptors (IRs), gustatory receptors (GRs), odorant binding proteins (OBPs) and chemosensory proteins (CSPs). In this work, we describe the chemosensory-related gene repertoire of the worldwide pest Spodoptera exigua (Lepidoptera: Noctuidae), focusing on the transcripts expressed in larvae, which feed on many horticultural crops producing yield losses. A comprehensive de novo assembly that includes reads from chemosensory organs of larvae and adults, and other larval tissues, enabled us to annotate 200 candidate chemosensory-related genes encoding 63 ORs, 28 IRs, 38 GRs, 48 OBPs and 23 CSPs. Of them, 51 transcripts are new annotations. Fifty ORs are expressed in larval heads based on RNA-seq and reverse transcription PCR analyses. Fourteen OBPs are expressed in larval, but not in adult heads. We also observe that expression profiles of ORs are strongly and non-specifically up-regulated upon pre-exposure of larvae to single volatile organic compounds (VOCs). Finally, we develop a behavioural assay to study the attraction/repellence to VOCs in S. exigua larvae and thus identify candidate ecologically relevant odours. A single-dose assay demonstrated that 1-hexanol triggers attraction and indole repels larvae at any timepoint. This work establishes the foundation for the study of chemosensation in S. exigua larvae, allowing further studies aimed to characterize chemosensory-related genes that underlie the ecologically relevant behaviours of larvae.

Novel RNA viruses producing simultaneous covert infections in Ceratitis capitata. Correlations between viral titers and host fitness, and implications for SIT programs.

The Mediterranean fruit fly (medfly), Ceratitis capitata is a highly polyphagous pest, which infests multiple species of fruits and vegetables worldwide. In addition to the traditional control with chemical insecticides, sterile insect technique (SIT) has been implemented in integrated programs worldwide, and has become an essential measure for the control of this pest. A key issue for SIT is to release sterile males that are sufficiently competitive with males from the wild population. Using sequence information available in public databases, three novel picornaviruses infecting medflies were discovered and named as C. capitata iflavirus 1 and 2 (CcaIV1 and CcaIV2), and C. capitata noravirus (CcaNV). Additional analyses have revealed the presence of CcaIV2 and CcaNV covertly infecting most of the medfly strains used in the different SIT programs around the world, as well as in field captures in the east of Spain. High viral titers of CcaNV were associated with a reduction in the lifespan of males released to the field for the control of this pest, suggesting the possibility that CcaNV may impair the fitness of sterile flies produced by SIT programs.

Influence of the hole geometry on the flow distribution in ventricular catheters for hydrocephalus.

BACKGROUND: Hydrocephalus is a medical condition consisting of an abnormal accumulation of cerebrospinal fluid within the brain. A catheter is inserted in one of the brain ventricles and then connected to an external valve to drain the excess of cerebrospinal fluid. The main drawback of this technique is that, over time, the ventricular catheter ends up getting blocked by the cells and macromolecules present in the cerebrospinal fluid. A crucial factor influencing this obstruction is a non-uniform flow pattern through the catheter, since it facilitates adhesion of suspended particles to the walls. In this paper we focus on the effects that tilted holes as well as conical holes have on the flow distribution and shear stress. METHODS: We have carried out 3D computational simulations to study the effect of the hole geometry on the cerebrospinal fluid flow through ventricular catheters. All the simulations were done with the OpenFOAM® toolbox. In particular, three different groups of models were investigated by varying (i) the tilt angles of the holes, (ii) the inner and outer diameters of the holes, and (iii) the distances between the so-called hole segments. RESULTS: The replacement of cylindrical holes by conical holes was found to have a strong influence on the flow distribution and to lower slightly the shear stress. Tilted holes did not involve flow distribution changes when the hole segments are sufficiently separated, but the mean shear stress was certainly reduced. CONCLUSIONS: The authors present new results about the behavior of the fluid flow through ventricular catheters. These results complete earlier work on this topic by adding the influence of the hole geometry. The overall objective pursued by this research is to provide guidelines to improve existing commercially available ventricular catheters.

Parametric study of ventricular catheters for hydrocephalus.

BACKGROUND: To drain the excess of cerebrospinal fluid in a hydrocephalus patient, a catheter is inserted into one of the brain ventricles and then connected to a valve. This so-called ventricular catheter is a standard-size, flexible tubing with a number of holes placed symmetrically around several transversal sections or "drainage segments". Three-dimensional computational dynamics shows that most of the fluid volume flows through the drainage segment closest to the valve. This fact raises the likelihood that those holes and then the lumen get clogged by the cells and macromolecules present in the cerebrospinal fluid, provoking malfunction of the whole system. In order to better understand the flow pattern, we have carried out a parametric study via numerical models of ventricular catheters. METHODS: The parameters chosen are the number of drainage segments, the distances between them, the number and diameter of the holes on each segment, as well as their relative angular position. RESULTS: These parameters were found to have a direct consequence on the flow distribution and shear stress of the catheter. As a consequence, we formulate general principles for ventricular catheter design. CONCLUSIONS: These principles can help develop new catheters with homogeneous flow patterns, thus possibly extending their lifetime.

Basic cerebrospinal fluid flow patterns in ventricular catheters prototypes.

OBJECT: A previous study by computational fluid dynamics (CFD) of the three-dimensional (3-D) flow in ventricular catheters (VC) disclosed that most of the total fluid mass flows through the catheter's most proximal holes in commercially available VC. The aim of the present study is to investigate basic flow patterns in VC prototypes. METHODS: The general procedure for the development of a CFD model calls for transforming the physical dimensions of the system to be studied into a virtual wire-frame model which provides the coordinates for the virtual space of a CFD mesh, in this case, a VC. The incompressible Navier-Stokes equations, a system of strongly coupled, nonlinear, partial differential conservation equations governing the motion of the flow field, are then solved numerically. New designs of VC, e.g., with novel hole configurations, can then be readily modeled, and the corresponding flow pattern computed in an automated way. Specially modified VCs were used for benchmark experimental testing. RESULTS: Three distinct types of flow pattern in prototype models of VC were obtained by varying specific parameters of the catheter design, like the number of holes in the drainage segments and the distance between them. Specifically, we show how to equalize and reverse the flow pattern through the different VC drainage segments by choosing appropriate parameters. CONCLUSIONS: The flow pattern in prototype catheters is determined by the number of holes, the hole diameter, the ratio hole/segment, and the distance between hole segments. The application of basic design principles of VC may help to develop new catheters with better flow circulation, thus reducing the possibility of becoming occluded.

New designs of ventricular catheters for hydrocephalus by 3-D computational fluid dynamics.

INTRODUCTION: Based on a landmark study by Lin et al. of the two-dimensional flow in ventricular catheters (VCs) via computational fluid dynamics (CFD), we studied in a previous paper the three-dimensional flow patterns of five commercially available VC. We found that the drainage of the cerebrospinal fluid (CSF) mostly occurs through the catheter's most proximal holes. In this paper, we design five VC prototypes with equalized flow characteristics. METHODS: We study five prototypes of VC by means of CFD in three-dimensional (3-D) automated models and compare the fluid-mechanical results with our previous study of currently in use VC. The general procedure for the development of a CFD model calls for transforming the physical dimensions of the system to be studied into a virtual wire-frame model, which provides the coordinates for the virtual space of a CFD mesh. The incompressible Navier-Stokes equations, a system of strongly coupled, nonlinear, partial differential equations governing the motion of the flow field, are then solved numerically. RESULTS: By varying the number of drainage holes and the ratio hole/segment, we improved flow characteristics in five prototypes of VC. Models 1, 2, and 3 have a distal to proximal decreasing flow. Model 4 has an inverse flow to the previous ones, that is, a distal to proximal increasing flow, while model 5 has a constant flow over the segments. CONCLUSIONS: New catheter designs with variable hole diameter, number of holes, and ratio hole/segment along the catheter allow the fluid to enter the catheter more uniformly along its length, thus reducing the chance that the catheter becomes occluded.

Computational fluid dynamics of ventricular catheters used for the treatment of hydrocephalus: a 3D analysis.

INTRODUCTION: The most common treatment for hydrocephalus remains the ventriculoperitoneal shunt. Yet, the most frequent complication is ventricular catheter obstruction, which may account for 50-80 % of newly inserted shunts. Although many factors contribute to this, the main one is related to flow characteristics of the catheter within the hydrocephalic brain. A landmark study by Lin et al. addressed the problem of fluid characteristics in ventricular catheters using a two-dimensional simulation program of computational fluid dynamics (CFD). METHODS: The authors have studied five current commercially available ventricular catheter designs using CFD in three-dimensional automated designs. The general procedure for the development of a CFD model involves incorporating the physical dimensions of the system to be studied into a virtual wire-frame model. The shape and features of the actual physical model are transformed into coordinates for the virtual space of the computer and a CFD computational grid (mesh) is generated. The fluid properties and motion are calculated at each of these grid points. After grid generation, flow field boundary conditions are applied, and the fluid's thermodynamic and transport properties are included. At the end, a system of strongly coupled, nonlinear, partial differential conservation equations governing the motion of the flow field are numerically solved. This numerical solution describes the fluid motion and properties. RESULTS: The authors calculated that most of the total fluid mass flows into the catheter's most proximal holes. Fifty to 75 % flows into the two most proximal sets of inlets of current commercially available 12-32-hole catheters. Some flow uniformity was disclosed in Rivulet-type catheter. CONCLUSIONS: Most commercially available ventricular catheters have an abnormally increase flow distribution pattern. New catheter designs with variable hole diameters along the catheter tip will allow the fluid to enter the catheter more uniformly along its length, thereby reducing the probability of its becoming occluded.

Cirugía Mayor Ambulatoria en el Hospital de la Ribera. Resultados obtenidos tras cinco años de funcionamiento / Major Surgery Outpatients Department (MSOD) in the Hospital de la Ribera. Results obtained after five years of running

Breve descripción de lo que es la CMA y análisis de la evolución de los resultados económicos y de satisfacción de la población tras cinco años de funcionamiento en el Hospital de La Ribera de Alzira (AU)

Brief description of the MSOD and an analysis of the evolution of the economic results and patient satisfaction after five years in the Hospital de La Ribera of Alzira (AU)