A5026640194- Nonlinear Dynamics and Pattern Formation
- COVID-19 epidemiological studies
- Advanced Fiber Laser Technologies
- Fluid Dynamics and Turbulent Flows
- Theoretical and Computational Physics
- Mosquito-borne diseases and control
- Fluid Dynamics and Thin Films
- Nonlinear Photonic Systems
- Solidification and crystal growth phenomena
- Slime Mold and Myxomycetes Research
- Data-Driven Disease Surveillance
- Laser-Matter Interactions and Applications
- Advanced Combinatorial Mathematics
- Semiconductor Lasers and Optical Devices
- Stochastic processes and statistical mechanics
- Micro and Nano Robotics
- Viral Infections and Vectors
- Nonlinear Waves and Solitons
- Quantum chaos and dynamical systems
- Dengue and Mosquito Control Research
- Surface Modification and Superhydrophobicity
- Force Microscopy Techniques and Applications
- Advanced Materials and Mechanics
- Mechanical and Optical Resonators
- Mathematical Dynamics and Fractals
University of Arizona
2014-2023
Google (United States)
2016
Connecticut Agricultural Experiment Station
2015
Centre National de la Recherche Scientifique
1995-1997
University of Strathclyde
1994-1996
Institut de Physique de Nice
1995
University of Cambridge
1995
University College Cork
1994
Université Côte d'Azur
1990-1992
Institut de Biologie Valrose
1992
We describe a turbulent state characterized by the presence of topological defects. This ‘‘topological turbulence’’ is likely to be experimentally observed in nonequilibrium systems.Received 23 November 1987DOI:https://doi.org/10.1103/PhysRevLett.62.1619©1989 American Physical Society
Short-term probabilistic forecasts of the trajectory COVID-19 pandemic in United States have served as a visible and important communication channel between scientific modeling community both general public decision-makers. Forecasting models provide specific, quantitative, evaluable predictions that inform short-term decisions such healthcare staffing needs, school closures, allocation medical supplies. Starting April 2020, US Forecast Hub ( https://covid19forecasthub.org/ ) collected,...
At equilibrium, Bloch walls are chiral interfaces between domains with different magnetization. Far from a set of forced oscillators can exhibit states phases. In this Letter, we show that when these become chiral, they move velocity simply related to their chirality. This surprising behavior is straightforward consequence nonvariational effects, which typical nonequilibrium systems.
Pattern formation in large aspect ratio, single longitudinal mode, two-level lasers with flat end reflectors, operating near peak gain, is shown to be described by a complex Swift-Hohenberg equation for class A and C coupled mean flow the case of B laser.
Abstract Since 2013, the Centers for Disease Control and Prevention (CDC) has hosted an annual influenza season forecasting challenge. The 2015–2016 challenge consisted of weekly probabilistic forecasts multiple targets, including fourteen models submitted by eleven teams. Forecast skill was evaluated using a modified logarithmic score. We averaged into mean ensemble model compared them against predictions based on historical trends. highest seasonal peak intensity short-term forecasts,...
Abstract Short-term probabilistic forecasts of the trajectory COVID-19 pandemic in United States have served as a visible and important communication channel between scientific modeling community both general public decision-makers. Forecasting models provide specific, quantitative, evaluable predictions that inform short-term decisions such healthcare staffing needs, school closures, allocation medical supplies. Starting April 2020, US Forecast Hub ( https://covid19forecasthub.org/ )...
The defects of a system where hexagons and rolls are both stable solutions considered. On the basis topological arguments we show that unstable phase is present in core defects. This means roll penta-hepta defect hexagon found grain boundary connecting with different orientations. These results verified an experiment thermal convection under non-Boussinesq conditions.
We identify the defects of waves by means topological arguments and study them in framework Landau-type analysis. It is shown that they correspond to sinks, sources, or dislocations traveling waves, standing waves.
We study some statistical properties of a turbulent state described by generalized Ginzburg-Landau equation and characterized topological defects.Received 30 May 1989DOI:https://doi.org/10.1103/PhysRevA.41.1138©1990 American Physical Society
We propose an improved Aedes aegypti (L.) abundance model that takes into account the effect of relative humidity (RH) on adult survival, as well rainfall-triggered egg hatching. The uses temperature-dependent development rates described in literature documented estimates for mosquito survival environments with high RH, and desiccation. show combining two additional components leads to better agreement surveillance trap data dengue incidence reports various municipalities Puerto Rico than...
Transverse pattern evolution is investigated in single-longitudinal-mode two-level and Raman lasers with flat end reflectors, subjected to uniform transverse pumping. The natural nonlinear modes of the laser are identified as spatially homogeneous when detuning from gain peak negative ``local'' plane traveling waves positive. latter correspond an off-axis emission laser. Stability characteristics underlying patterns predicted be quite different for one-dimensional two-dimensional (2D)...
A turbulent behaviour of wave patterns is described, which related to the presence dislocations. By means numerical simulations 2D complex Ginzburg-Landau equations, it shown that phase instability leads in spatially extended systems spontaneous nucleation topological defects. The appearance these localized amplitude perturbations interpreted as consequence revolt slaved modes. Once created, those defects move through system and break order induced by pattern. resulting state has been termed...
Recent events have thrown the spotlight on infectious disease outbreak response. We developed a data-driven method, EpiGro, which can be applied to cumulative case reports estimate order of magnitude duration, peak and ultimate size an ongoing outbreak. It is based surprisingly simple mathematical property many epidemiological data sets, does not require knowledge or estimation transmission parameters, robust noise small runs quickly due its simplicity. Using from historic epidemics, we...
We propose a hydrodynamic model for the evolution of bacterial colonies growing on soft agar plates. This consists reaction-diffusion equations concentrations nutrients, water, and bacteria, coupled to single equation velocity field bacteria-water mixture. It captures dynamics inside colony as well its boundary allows us identify mechanism collective motion towards fresh which, in modeling aspects, is similar classical chemotaxis. As shown numerical simulations, our reproduces both usual...
Complex order-parameter equation descriptions of pattern evolution in large-aspect-ratio two-level and Raman lasers are derived systematically as solvability conditions a multiple-scales asymptotic expansion the original Maxwell-Bloch laser equations powers small parameter. These amplitude equations, although strictly valid near threshold for lasing, shown to capture essential features instability well beyond lasing threshold. A technical difficulty that can arise laser, namely,...
Finite time singularity formation in a fourth order nonlinear parabolic partial differential equation (PDE) is analyzed. The PDE variant of ubiquitous model found the field Micro-Electro Mechanical Systems (MEMS) and studied on one-dimensional (1D) strip unit disc. solution itself remains continuous at point while its higher derivatives diverge, phenomenon known as quenching. For certain parameter regimes it shown numerically that will form multiple isolated points 1D case along ring...
Abstract While estimates of the impact climate change on health are necessary for care planners and policy makers, models to produce quantitative remain scarce. This study describes a freely available dynamic simulation model parameterized three West Nile virus vectors, which provides an effective tool studying vectorborne disease risk due change. The Dynamic Mosquito Simulation Model is with species-specific temperature-dependent development mortality rates. Using downscaled daily weather...
We both analytically and numerically show the existence of a drift Bloch walls when submitted to uniform parallel-to-the-wall-plane rotating magnetic field. The velocity changes sign with wall handedness is proportional amplitude square field, latter small.