Low-cost fermions in classical field simulations

We discuss the possible extension of the bosonic classical field theory simulations to include fermions. This problem has been addressed in terms of the inhomogeneous mean field approximation by Aarts and Smit. By performing a stochastic integration of an equivalent set of equations we can extend the original 1+1 dimensional calculations so that they become feasible in higher dimensions. We test the scheme in 2 + 1 dimensions and discuss some classical applications with fermions for the first time, such as the decay of oscillons.Comment: 13 pages, revtex

Renormalised nonequilibrium quantum field theory: scalar fields

We discuss the renormalisation of the initial value problem in quantum field theory using the two-particle irreducible (2PI) effective action formalism. The nonequilibrium dynamics is renormalised by counterterms determined in equilibrium. We emphasize the importance of the appropriate choice of initial conditions and go beyond the Gaussian initial density operator by defining self-consistent initial conditions. We study the corresponding time evolution and present a numerical example which supports the existence of a continuum limit for this type of initial conditions.Comment: 18 pages in revtex4, 5 figure

Classical Simulation of Quantum Fields II

We consider the classical time evolution of a real scalar field in 2 dimensional Minkowski space with a $\lambda \phi^4$ interaction. We compute the spatial and temporal two-point correlation functions and extract the renormalized mass of the interacting theory. We find our results are consistent with the one- and two-loop quantum computation. We also perform Monte Carlo simulations of the quantum theory and conclude that the classical scheme is able to produce more accurate results with a fraction of the CPU time.Comment: 16 pages, 8 figures, now matches published versio

Lyapunov Control on Quantum Open System in Decoherence-free Subspaces

A scheme to drive and manipulate a finite-dimensional quantum system in the decoherence-free subspaces(DFS) by Lyapunov control is proposed. Control fields are established by Lyapunov function. This proposal can drive the open quantum system into the DFS and manipulate it to any desired eigenstate of the free Hamiltonian. An example which consists of a four-level system with three long-lived states driven by two lasers is presented to exemplify the scheme. We have performed numerical simulations for the dynamics of the four-level system, which show that the scheme works good.Comment: 5 pages, 6 figure

The COVID-19 consumption game-changer: Evidence from a large-scale multi-country survey

Prospective economic developments depend on the behavior of consumer spending. A key question is whether private expenditures recover once social distancing restrictions are lifted or whether the COVID-19 crisis has a sustained impact on consumer confidence, preferences, and, hence, spending. The elongated and profound experience of the COVID-19 crisis may durably affect consumer preferences. We conducted a representative consumer survey in five European countries in summer 2020, after the release of the first wave’s lockdown restrictions, and document the underlying reasons for households’ reduction in consumption in five key sectors: tourism, hospitality, services, retail, and public transports. We identify a large confidence shock in the Southern European countries and a shift in consumer preferences in the Northern European countries, particularly among high-income earners. We conclude that the COVID-19 experience has altered consumer behavior and that long-term sectoral consumption shifts may occur

Ultrasound evaluation of access complications: Thrombosis, aneurysms, pseudoaneurysms and infections

: Arteriovenous fistula (AVF) complications are classified based on fistula outcomes. This review aims to update colour Doppler (CD) and pulse wave Doppler (PWD) roles in managing early and late complications of the native and prosthetic AVF. Vascular access (VA) failure occurs because inflow or outflow stenosis activates Wirchow's triad inducing thrombosis. Therefore, the diagnosis of the tributary artery and outgoing vein stenosis will be the first topic considered. Post-implantation complications occur from the inability to achieve AVF maturation and dialysis suitability due to inflow/outflow stenosis. Late stenosis is usually a sequence of early defects repaired to maintain patency. Less frequently, in the mature AVF or graft, complications are acquired 'de novo'. They derive either from incorrect management of vascular access (haematoma, pseudoaneurysm, prosthesis infection) or wall pathologies (aneurysm, myxoid valve degeneration, kinking, coiling, abnormal dilation from defects of elastic structures). High-resolution transducers (10-20 MHz) allow the characterization of the wall damage, haemodynamic dysfunctions, early and late complications even if phlebography remains the gold standard for the diagnosis for its sensitivity and specificity

Feeding and oviposition preferences of Monochamus galloprovincialis on its main hosts Pinus sylvestris and Pinus pinaster

Θεωρώντας τον ρόλο του Monochamus galloprovincialis κλειδί στην εξάπλωση του νηματώδη του πεύκου στην Ευρώπη, η διαλεύκανση του εύρους των ξενιστών και των προτιμήσεων του Μ. galloprovincialis σε αυτούς είναι πρωτεύουσας σημασίας για την προστασία του δάσους. Συγκριτικές μελέτες σε συνθήκες εργαστηρίου διεξήχθησαν με σκοπό την διευκρίνηση των διατροφικών και ωοθετικών προτιμήσεων των ενηλίκων αυτού του εντόμου καθώς και της ανάπτυξης των προνυμφών του στα P. sylvestris και P. pinaster. Η διατροφή και η ωοτοκία βρέθηκαν στατιστικά πιο σημαντικές στο P. sylvestris αλλά καμία διαφορά δεν βρέθηκε στην επιβίωση των προνυμφών στα δύο είδη πεύκου. Οι προνύμφες έφτασαν στην 4η ηλικία νωρίτερα στο P. sylvestris από ότι στο P. pinaster. Τα αποτελέσματα της παρούσης μελέτης ισχυροποιούν τις υποψίες για μια γρήγορη μελλοντική εξάπλωση του νηματώδη σε ολόκληρη την Ευρώπη.Considering the key role of Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae) in the dispersion of the pine wood nematode, Bursaphelenchus xylophilus (Steiner & Bührer) Nickle (Nematoda: Aphelenchoidea), in Europe, defining the host spectrum and preference of M. galloprovincialis is of primary importance for forest management. Therefore, comparative studies under laboratory conditions were performed in order to define the feeding and oviposition preferences of M. galloprovincialis adults as well as the larval development on Pinus sylvestris and Pinus pinaster. Both nutrition and oviposition were significantly higher on P. sylvestris. However, no difference was found when comparing larval survival on the two Pinus species even though larvae attended the fourth instar earlier when reared on P. sylvestris than on P. pinaster. The results of this study reinforce the suspicions of a future rapid propagation of the nematode, by M. galloprovincialis, into the Pine forests all over Europe

Legal Protection on Indigenous Peoples in the Utilization of Coastal Area and Small Islands

The main purpose of this scientific paper is to know in which extent the State of Indonesia as a sovereign country, able to provide legal protection against indigenous peoples in coastal areas and small islands in the utilization of its territory. During this time, the State's concern in establishing maritime is still pulling out, due to renewal and development in various sectors still tend to be centralized, centered on the land and urban areas. This makes the coastal areas and small islands vulnerable to various obstacles and challenges, including in accommodating the interests of indigenous peoples who are acknowledged to exist in the Basic Agrarian Law. Meanwhile, the existing legislation concerning the use of coastal areas and small islands is more oriented to the exploitation regardless of the sustainability of natural resources. In this case, the existence of indigenous peoples of coastal areas and small island islands play an important role in the management of marine areas throughout Indonesia. The feature of the traditional lives and the behavioral patterns of indigenous peoples that respect nature and the sea which can help its management to be better, maintain ecological balance and sustainable principles. In fact, there are still many indigenous peoples in the coastal areas and small islands that form a legal alliance, far from accessibility. The establishment of various regulations governing the utilization and management of coastal areas and small islands, as well as the limited reference and information of indigenous peoples on the subject, is feared to cause problems and irregularities in the implementation. Therefore, in this matter it is necessary to have further regulation as supervision and control measures. The regulation is expected to engage indigenous peoples in a participatory manner in order to be able to produce inclusive legal products, hence the birth of regulation is no longer tend to overlap or be understood as a paradoxical rule. Keywords: coastal area, small islands, indigenous peoples, communal right on sea, basic agrarian la