17 research outputs found
Bright and Dark Solitons on the Surface of Finite-Depth Fluid Below the Modulation Instability Threshold
We use the high-order nonlinear Schr\"{o}dinger equation (NLSE) derived to
model the evolution of slowly modulated wave trains with narrow spectrum on the
surface of ideal finite-depth fluid. This equation is the finite-depth
counterpart of celebrated Dysthe's equation, which is usually used for the same
purpose in the case of infinite depth. We demonstrate that this generalized
equation admits bright soliton solutions for depths below the modulation
instability threshold ( being the carrier wave number and
the undisturbed fluid depth), which is not possible in the case of standard
NLSE. These bright solitons can exist along with the dark solitons that have
recently been observed in a water wave tank [Phys. Rev. Lett. 110, 124101
(2013)].Comment: 5 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1501.0593
Modeling and Controlling the Spread of Epidemic with Various Social and Economic Scenarios
We propose a dynamical model for describing the spread of epidemics. This
model is an extension of the SIQR (susceptible-infected-quarantined-recovered)
and SIRP (susceptible-infected-recovered-pathogen) models used earlier to
describe various scenarios of epidemic spreading. As compared to the basic SIR
model, our model takes into account two possible routes of contagion
transmission: direct from the infected compartment to the susceptible
compartment and indirect via some intermediate medium or fomites. Transmission
rates are estimated in terms of average distances between the individuals in
selected social environments and characteristic time spans for which the
individuals stay in each of these environments. We also introduce a collective
economic resource associated with the average amount of money or income per
individual to describe the socioeconomic interplay between the spreading
process and the resource available to infected individuals. The
epidemic-resource coupling is supposed to be of activation type, with the
recovery rate governed by the Arrhenius-like law. Our model brings an advantage
of building various control strategies to mitigate the effect of epidemic and
can be applied, in particular, to modeling the spread of COVID-19.Comment: 14 pages, 6 figures, 5 table
Steep sharp-crested gravity waves on deep water
A new type of steady steep two-dimensional irrotational symmetric periodic
gravity waves on inviscid incompressible fluid of infinite depth is revealed.
We demonstrate that these waves have sharper crests in comparison with the
Stokes waves of the same wavelength and steepness. The speed of a fluid
particle at the crest of new waves is greater than their phase speed.Comment: 4 pages, 2 figures, submitted to Phys. Rev. Let
A toy model for the epidemic-driven collapse in a system with limited economic resource
Based on a toy model for a trivial socioeconomic system, we demonstrate that the activation-type mechanism of the epidemic-resource coupling can lead to the collapsing effect opposite to thermal explosion. We exploit a SIS-like (susceptible-infected-susceptible) model coupled with the dynamics of average economic resource for a group of active economic agents. The recovery rate of infected individuals is supposed to obey the Arrhenius-like law, resulting in a mutual negative feedback between the number of active agents and resource acquisition. The economic resource is associated with the average amount of money or income per agent and formally corresponds to the effective market temperature of agents, with their income distribution obeying the Boltzmann–Gibbs statistics. A characteristic level of resource consumption is associated with activation energy. We show that the phase portrait of the system features a collapse phase, in addition to the well-known disease-free and endemic phases. The epidemic intensified by the increasing resource deficit can ultimately drive the system to a collapse at nonzero activation energy because of limited resource. We briefly discuss several collapse mitigation strategies involving either financial instruments like subsidies or social regulations like quarantine
STR Profiling for Discrimination between Wild and Domestic Swine Specimens and between Main Breeds of Domestic Pigs Reared in Belarus
<div><p>A panel comprising 16 short tandem repeats (STRs) and a gender-specific amelogenin marker was worked out and tested for robustness in discrimination between wild and domestic swine subspecies encountered in Europe, between regional populations of wild boars and between main breeds of domestic pigs reared in Belarus. The STR dataset comprised 310 wild boars, inhabiting all administrative regions of Belarus, and 313 domestic pigs, representing three local and three cosmopolitan lines. Additionally, a total of 835 wild boars were genotyped for the presence of melanocortin 1 receptor (<i>MC1R</i>) alleles specific for domestic pigs. Correctness of assignment of STR profiles to appropriate populations was measured by log-likelihood ratios (log-LRs). All samples were correctly identified as wild boars or domestic pigs with average log-LR of 42.4 (LR = 2.6×10<sup>18</sup>). On the other hand, as many as 50 out of 835 (6.0%) genotyped wild boars from Belarus possessed <i>MC1R</i> alleles specific to domestic pigs, demonstrating supremacy of our STR profiling system over traditional differentiation between wild boars and domestic pigs, based on single binary markers. Mean log-LRs for allocation of wild boars to their regions of origin and of domestic pigs to appropriate breeds were 2.3 (LR = 9.7) and 13.4 (LR = 6.6×10<sup>5</sup>), respectively. Our results demonstrate the developed STR profiling system to be a highly efficient tool for differentiation between wild and domestic swine subspecies and between diverse breeds of domestic pigs as well as for verification of genetic identity of porcine specimens for the purpose of forensic investigations of wildlife crimes, assurance of veterinary public health, parentage control in animal husbandry, food safety management and traceability of livestock products.</p></div