Critical wetting of a class of nonequilibrium interfaces: A mean-field picture

A self-consistent mean-field method is used to study critical wetting transitions under nonequilibrium conditions by analyzing Kardar-Parisi-Zhang (KPZ) interfaces in the presence of a bounding substrate. In the case of positive KPZ nonlinearity a single (Gaussian) regime is found. On the contrary, interfaces corresponding to negative nonlinearities lead to three different regimes of critical behavior for the surface order-parameter: (i) a trivial Gaussian regime, (ii) a weak-fluctuation regime with a trivially located critical point and nontrivial exponents, and (iii) a highly non-trivial strong-fluctuation regime, for which we provide a full solution by finding the zeros of parabolic-cylinder functions. These analytical results are also verified by solving numerically the self-consistent equation in each case. Analogies with and differences from equilibrium critical wetting as well as nonequilibrium complete wetting are also discussed.Comment: 11 pages, 2 figure

Native rodent species are unlikely sources of infection for Leishmania (Viannia) braziliensis along the Transoceanic Highway in Madre de Dios, Peru.

An estimated 2.3 million disability-adjusted life years are lost globally from leishmaniasis. In Peru's Amazon region, the department of Madre de Dios (MDD) rises above the rest of the country in terms of the annual incidence rates of human leishmaniasis. Leishmania (Viannia) braziliensis is the species most frequently responsible for the form of disease that results in tissue destruction of the nose and mouth. However, essentially nothing is known regarding the reservoirs of this vector-borne, zoonotic parasite in MDD. Wild rodents have been suspected, or proven, to be reservoirs of several Leishmania spp. in various ecosystems and countries. Additionally, people who live or work in forested terrain, especially those who are not regionally local and whose immune systems are thus naïve to the parasite, are at most risk for contracting L. (V.) braziliensis. Hence, the objective of this study was to collect tissues from wild rodents captured at several study sites along the Amazonian segment of the newly constructed Transoceanic Highway and to use molecular laboratory techniques to analyze samples for the presence of Leishmania parasites. Liver tissues were tested via polymerase chain reaction from a total of 217 rodents; bone marrow and skin biopsies (ear and tail) were also tested from a subset of these same animals. The most numerous rodent species captured and tested were Oligoryzomys microtis (40.7%), Hylaeamys perenensis (15.7%), and Proechimys spp. (12%). All samples were negative for Leishmania, implying that although incidental infections may occur, these abundant rodent species are unlikely to serve as primary reservoirs of L. (V.) braziliensis along the Transoceanic Highway in MDD. Therefore, although these rodent species may persist and even thrive in moderately altered landscapes, we did not find any evidence to suggest they pose a risk for L. (V.) braziliensis transmission to human inhabitants in this highly prevalent region

Critical wetting of a class of nonequilibrium interfaces: A computer simulation study

Critical wetting transitions under nonequilibrium conditions are studied numerically and analytically by means of an interface-displacement model defined by a Kardar-Parisi-Zhang equation, plus some extra terms representing a limiting, short-ranged attractive wall. Its critical behavior is characterized in detail by providing a set of exponents for both the average height and the surface order-parameter in one dimension. The emerging picture is qualitatively and quantitatively different from recently reported mean-field predictions for the same problem. Evidence is shown that the presence of the attractive wall induces an anomalous scaling of the interface local slopes.Comment: 7 pages, 8 figure

The Railway Line Frequency and Size Setting Problem

[EN] The problem studied in this paper takes as input data a set of lines forming a railway network, and an origin¿destination (OD) matrix. The OD pairs may use either the railway network or an alternative transportation mode. The objective is to determine the frequency/headway of each line as well as its number of carriages, so that the net profit of the railway network is maximized. We propose a mixed integer non-linear programming formulation for this problem. Because of the computational intractability of this model, we develop four algorithms: a mixed integer linear programming (MIP) model, a MIP-based iterative algorithm, a shortest-path based algorithm, and a local search. These four algorithms are tested and compared over a set of randomly generated instances. An application over a case study shows that only the local search heuristic is capable of dealing with large instances.This research was partly funded by the Canadian Natural Sciences and Engineering Research Council under Grant 2015-06189, by the Ministerio de Economía y Competitividad (Spain)/FEDER under projects MTM2012-37048, MTM2015-67706-P and DPI2012-36243-C02-01, and by Junta de Andalucía (Spain)/FEDER under excellence project P10-FQM-5849. Part of this research was done while Federico Perea was enjoying a research visit to CIRRELT, funded by the Universitat Politècnica de València, under program PAID-00-15. This support is gratefully acknowledged. Thanks are due to the referees for their valuable comments.De-Los-Santos, A.; Laporte, G.; Mesa, JA.; Perea Rojas Marcos, F. (2017). The Railway Line Frequency and Size Setting Problem. Public Transport. 9(1-2):33-53. https://doi.org/10.1007/s12469-017-0154-2S335391-2Albrecht T (2009) Automated timetable design for demand-oriented service on suburban railways. Public Transport 1(1):5–20Caprara A, Kroon L, Monaci M, Peeters M, Toth P (2007) Passenger Railway optimization. In: Barnhart C, Laporte G (eds) Handbooks in operations research and management science, vol 14. Transportation, chapter 3. North-Holland, Amsterdam, pp 129–187De-Los-Santos A, Laporte G, Mesa J, Perea F (2014) Simultaneous frequency and capacity setting in uncapacitated metro lines in presence of a competing mode. Transp Res Proc 3:289–298Desaulniers G, Hickman M (2007) Public transport. In: Barnhart C, Laporte G (eds) Handbook in operations research and management science, vol 14, Transportation, chapter 2. North-Holland, Amsterdam, pp 69–127Gallo M, Montella B, D’Acierno L (2011) The transit network design problem with elastic demand and internalisation of external costs: An application to rail frequency optimisation. Transp Res Part C Emerg Technol 19(6):1276–1305Laporte G, Marín A, Mesa JA, Perea F (2011) Designing robust rapid transit networks with alternative routes. J Adv Transp 45(1):54–65Marín A, García-Ródenas R (2009) Location of infrastructure in urban railway networks. Comput Oper Res 36(5):1461–1477Michaelis M, Schöbel A (2009) Integrating line planning, timetable, and vehicle scheduling: a customer oriented heuristic. Public Transport 1(3):211–232Perea F, Mesa JA, Laporte G (2014) Adding a new station and a road link to a road-rail network in the presence of modal competition. Transp Res Part B Methodol 68:1–16Schmidt M, Schöbel A (2015) The complexity of integrating passenger routing decisions in public transportation models. Networks 65(3):228–243Schmidt ME (2014) Integrating routing decisions in public transportation problems. Springer, New YorkSchöbel A (2012) Line planning in public transportation. OR Spectrum 34:491–510van Oort N, van Nes R (2009) Regularity analysis for optimizing urban transit network design. Public Transport 1(2):155–168Vuchic VR (2005) Urban transit: operations, planning, and economics. Wiley, Hoboken, New Jerse

Quantum capacitor with discrete charge-anticharge: spectrum and forces

The quantum capacitor with discrete charge is modeled by a Hamiltonian containing an inductive intrinsic term (tunnel effect between plates). The spectrum is obtained using a double Hilbert space. Fluctuations in the charge-anticharge pairs (zero total charge) give rise to an elementary attraction which is compared to the Casimir force. In this case, the field-fluctuations force could be also interpreted as charge-fluctuations force

Nonequilibrium wetting transitions with short range forces

We analyze within mean-field theory as well as numerically a KPZ equation that describes nonequilibrium wetting. Both complete and critical wettitng transitions were found and characterized in detail. For one-dimensional substrates the critical wetting temperature is depressed by fluctuations. In addition, we have investigated a region in the space of parameters (temperature and chemical potential) where the wet and nonwet phases coexist. Finite-size scaling analysis of the interfacial detaching times indicates that the finite coexistence region survives in the thermodynamic limit. Within this region we have observed (stable or very long-lived) structures related to spatio-temporal intermittency in other systems. In the interfacial representation these structures exhibit perfect triangular (pyramidal) patterns in one (two dimensions), that are characterized by their slope and size distribution.Comment: 11 pages, 5 figures. To appear in Physical Review

Detección de pacientes COVID-19 en muestras de sudor por medio del olfato canino: Estudio preliminar

Volatile Organic Compounds generated by changes in the metabolism of an individual have been used for the diagnosis of diseases through canine sense of smell. There is evidence of the generation of these compounds in SARS-COV-2 infection. The objective of the work was to determine the canine capacity to discriminate between positive and negative patients with COVID-19 through samples of axillary sweat. Axillary sweat samples were used from 102 hospitalized patients both COVID-19 positive (31) and negative (71), all diagnosed by rt-PCR test. For each round of detection, a single positive sample was placed and the rest of the samples (whether 1, 2, 3, 4, or 5) were negative. The overall sensitivity and specificity were 93.11% (± 3.14%) and 88.52% (± 4.64%) respectively. The high sensitivity could be due to the longer train­ing thus increasing the accuracy in the detection of positive samples. The specificity was than lower another published and may be due to the fact that the negative samples came from people hospitalized for other pathologies or were companions of hospitalized family members, so that all had a hospitable odor. Detecting COVID-19 patients using canine smell has proven to be a reliable and promising sieve test.Los componentes orgánicos volátiles generados por cambios en el metabolismo de un individuo han sido utilizados para el diagnóstico de enfermedades a través del olfato canino. Hay evidencias sobre la generación de dichos componentes en la infección por SARS-COV-2. El objetivo del trabajo fue determinar la capacidad canina para discriminar a pacientes positivos y negativos a COVID-19 a través de muestras de sudor axilar. Se utilizaron muestras de sudor axilar de 102 pacientes hospitalizados tanto COVID-19 positivos (31) como negativos (71), todos diagnosticados mediante la prueba de RT-PCR. Por cada ronda de detección se colocó una única muestra positiva y el resto de las muestras (sean 1, 2, 3, 4 o 5) negativas. La sensibilidad y especificidad global fue de 93,11% (± 3,14%) y 88,52% (± 4,64%) respectivamente. La alta sensibilidad pudo deberse al entrenamiento más prolongado aumentando así, la exactitud en la detección de muestras positivas. La especificidad fue menor a otra publicada pudiéndose deber a que las muestras negativas provenían de personas internadas por otras patologías o eran acompañantes de familiares internados por lo que todas poseían olor hospitalario. La detección de pacientes COVID-19 mediante el olfato canino ha demostrado ser una prueba tamiz confiable y prometedora

Nonequilibrium wetting

When a nonequilibrium growing interface in the presence of a wall is considered a nonequilibrium wetting transition may take place. This transition can be studied trough Langevin equations or discrete growth models. In the first case, the Kardar-Parisi-Zhang equation, which defines a very robust universality class for nonequilibrium moving interfaces, with a soft-wall potential is considered. While in the second, microscopic models, in the corresponding universality class, with evaporation and deposition of particles in the presence of hard-wall are studied. Equilibrium wetting is related to a particular case of the problem, it corresponds to the Edwards-Wilkinson equation with a potential in the continuum approach or to the fulfillment of detailed balance in the microscopic models. In this review we present the analytical and numerical methods used to investigate the problem and the very rich behavior that is observed with them.Comment: Review, 36 pages, 16 figure

Heuristic derivation of continuum kinetic equations from microscopic dynamics

We present an approximate and heuristic scheme for the derivation of continuum kinetic equations from microscopic dynamics for stochastic, interacting systems. The method consists of a mean-field type, decoupled approximation of the master equation followed by the `naive' continuum limit. The Ising model and driven diffusive systems are used as illustrations. The equations derived are in agreement with other approaches, and consequences of the microscopic dependences of coarse-grained parameters compare favorably with exact or high-temperature expansions. The method is valuable when more systematic and rigorous approaches fail, and when microscopic inputs in the continuum theory are desirable.Comment: 7 pages, RevTeX, two-column, 4 PS figures include