The INTERNODES method for the treatment of non-conforming multipatch geometries in Isogeometric Analysis

In this paper we apply the INTERNODES method to solve second order elliptic problems discretized by Isogeometric Analysis methods on non-conforming multiple patches in 2D and 3D geometries. INTERNODES is an interpolation-based method that, on each interface of the configuration, exploits two independent interpolation operators to enforce the continuity of the traces and of the normal derivatives. INTERNODES supports non-conformity on NURBS spaces as well as on geometries. We specify how to set up the interpolation matrices on non-conforming interfaces, how to enforce the continuity of the normal derivatives and we give special attention to implementation aspects. The numerical results show that INTERNODES exhibits optimal convergence rate with respect to the mesh size of the NURBS spaces an that it is robust with respect to jumping coefficients.Comment: Accepted for publication in Computer Methods in Applied Mechanics and Engineerin

Extended Variational Formulation for Heterogeneous Partial Differential Equations

We address the coupling of an advection equation with a diffusion-advection equation, for solutions featuring boundary layers. We consider non-overlapping domain decompositions and we face up the heterogeneous problem using an extended variational formulation. We will prove the equivalence between the latter formulation and a treatment based on a singular perturbation theory. An exhaustive comparison in terms of solution and computational efficiency between these formulations is carried ou

The interface control domain decomposition (ICDD) method for elliptic problems

Interface controls are unknown functions used as Dirichlet or Robin boundary data on the interfaces of an overlapping decomposition designed for solving second order elliptic boundary value problems. The controls are computed through an optimal control problem with either distributed or interface observation. Numerical results show that, when interface observation is considered, the resulting interface control domain decomposition method is robust with respect to coefficients variations; it can exploit nonconforming meshes and provides optimal convergence with respect to the discretization parameters; finally it can be easily used to face heterogeneous advection--advection-diffusion couplings

Assessing the risk of establishment and transient populations of Spodoptera frugiperda in Europe

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is an invasive pest threatening crop production and food security worldwide. High concerns are linked to the potential establishment of the species in Europe. The high migratory capacity of S. frugiperda causes concerns about the potential impacts of transient populations invading new areas from suitable hotspots. In the present work, we developed and used a physiologically-based demographic model to quantitatively assess the risks of S. frugiperda in Europe. The risks were assessed considering a best-, a median-, and a worst-case scenario. The Mediterranean coastal areas of Southern Europe resulted particularly suitable for the establishment of the species, with suitable areas reaching even higher latitudes, in the worst-case scenario. In Europe, up to four generations per year were predicted. The predicted yearly average number of moths per trap per week (± standard deviation) was 5 (± 4), 17 (± 5), and 139 (± 22) in the best, median-, and worst-case assessment scenarios, respectively. Model results showed that Southern and Central Europe up to the 48th parallel north might be exposed to the risk of transient populations. Depending on the latitude and on the period of arrival of the propagule, 1–2 transient generations per year might be expected. The model can be used to define strategies for reducing the risks of establishment of the pest at the country level. Predictions on the dynamics and phenology of the pest can also be used to support its management at the local level

Predicting the spatio-temporal dynamics of Popillia japonica populations

We developed a reaction–diffusion model to describe the spatio-temporal dynamics of the Japanese beetle (Popillia japonica Newman), based on adult abundance data collected by the Regional Phytosanitary Service during the monitoring activities in the infested area in Lombardy (northern Italy), from 2015 to 2021. The model simulated the abundance of the pest, with a discrete time step of one year along linear trajectories departing from an initial point of establishment. The model allowed the determination of the rate of expansion (i.e. the speed at which the leading edge of a population wave moves over time) of the pest along 13 different trajectories, ranging from 4.5 to 13.8 km/y, with a mean value of 8.2 km/y. Finally, we developed a land suitability index that summarises the effect of land use on the trajectory-specific rate of expansion of P. japonica. Specifically, the model revealed an increase in the rate of expansion of 260 m per year for each additional percentage point in the land suitability index. The model presented and the knowledge acquired in this work represent an important step forward in the comprehension of P. japonica population dynamics, and they represent important elements for the development of a decision support tool for pest risk managers to design and implement scientifically driven management actions

Structure of the connexin-43 gap junction channel in a putative closed state

Gap junction channels (GJCs) mediate intercellular communication by connecting two neighbouring cells and enabling direct exchange of ions and small molecules. Cell coupling via connexin-43 (Cx43) GJCs is important in a wide range of cellular processes in health and disease (Churko and Laird, 2013; Liang et al., 2020; Poelzing and Rosenbaum, 2004), yet the structural basis of Cx43 function and regulation has not been determined until now. Here, we describe the structure of a human Cx43 GJC solved by cryo-EM and single particle analysis at 2.26 Å resolution. The pore region of Cx43 GJC features several lipid-like densities per Cx43 monomer, located close to a putative lateral access site at the monomer boundary. We found a previously undescribed conformation on the cytosolic side of the pore, formed by the N-terminal domain and the transmembrane helix 2 of Cx43 and stabilized by a small molecule. Structures of the Cx43 GJC and hemichannels (HCs) in nanodiscs reveal a similar gate arrangement. The features of the Cx43 GJC and HC cryo-EM maps and the channel properties revealed by molecular dynamics simulations suggest that the captured states of Cx43 are consistent with a closed state

Simulazione della diapausa e della fenologia del coleottero Giapponese, Popillia japonica

Il coleottero giapponese (Popillia japonica Newman) è una specie polifaga e invasiva originaria del nord-est asiatico. Fin dalla sua prima individuazione negli Stati Uniti nel 1916, la specie è stata in grado di invadere vaste aree del nord America ed alcune aree del Canada meridionale. Negli anni '70, la P. japonica è stata introdotta nelle Azzorre e dal 2014 la specie si è insediata in Europa continentale (Italia). Dal 2017, in Svizzera sono stati segnalati alcuni avvistamenti della specie. In Italia, la P. japonica è distribuita lungo la Valle del Ticino al confine tra Lombardia e Piemonte e, dalla sua prima individuazione, l’area di infestazione è incrementata nel tempo. La specie è considerata un organismo da quarantena e quindi il Servizio Fitosanitario Nazionale Italiano e i due Servizi Fitosanitari Regionali stanno attuando misure volte al monitoraggio e al contenimento di P. japonica. Il controllo delle popolazioni di P. japonica può essere supportato dall’uso di modelli in grado di predire le tempistiche di emergenza degli stadi vitali suscettibili (ad esempio, larve e adulti). In questo lavoro, presentiamo un modello meccanicistico per simulare l’influenza della temperatura sull’inizio dei voli e sulla curva fenologica degli adulti di P. japonica. Il modello è stato calibrato e validato utilizzando serie temporali relative alla cattura di individui adulti tramite trappole a feromoni. I dati sono stati raccolti dal Servizio Fitosanitario della Regione Lombardia (Italia). Il modello è in grado di simulare realisticamente l’influenza della temperatura del suolo sui pattern di sviluppo e sulle strategie dei cicli di vita della specie. L’applicazione del modello a scala locale (ad esempio, simulazioni a livello puntuale) possono supportare i decisori (agricoltori, cooperative agricole ecc.) nella pianificazione e implementazione di azioni volte al monitoraggio e al controllo delle popolazioni basate sulle tempistiche di emergenza stimate dal modello. Il modello può essere inoltre applicato su scala regionale per ottenere mappe fenologiche che permettano di identificare le aree dove è prevista una emergenza anticipata della specie. Questa informazione può supportare i decisori che agiscono a livello regionale (ad esempio Servizi Fitosanitari Regionali) nella prioritizzazione delle aree di intervento, nell’implementazione di sistemi di allerta e nell’implementazione di piani di gestione della specie su scala regionale. Finanziamento: Il Progetto GESPO è Finanziato da “Direzione Generale Agricoltura - Regione Lombardia - D.d.s. 28 marzo 2018 - n. 4403D.g.r. n. X/7353 14 novembre 2017”

Expected implications of climate change on the corrosion of structures

The report presents the work of the Joint Research Centre (JRC) scientific network on adaptation of structural design to climate change addressing the expected implications of a changing climate on the corrosion of structures. The work first outlines recent EU policies supporting the sustainability and climate resilience of infrastructure and buildings. It is highlighted how the construction sector is encouraged to adopt more sustainable and circular economic practices, extend the lifetime of buildings and strive for better performance of buildings and infrastructure throughout their life cycle. The ongoing action plan to adapt European standards to a changing climate is emphasised. The report evaluates the expected variations in climatic factors causing corrosion, provides a state-of-the-art review on climate change induced corrosion of reinforced concrete and steel structures, and presents recent works on the corrosion impact, the costs and effectiveness of adaptation strategies. The effects of corrosion on the seismic performance of structures is addressed as well. In conclusion, this report presents the scientific and technical background to study the expected implications of climate change on the corrosion of structures. The work intends to stimulate debate on the subject, identify further research needs, and serve as a basis for the development of further work relevant to the adaptation to climate change of European standards and policies.JRC.E.4-Safety and Security of Building

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe