Semiclassical propagator of the Wigner function

Propagation of the Wigner function is studied on two levels of semiclassical propagation, one based on the van-Vleck propagator, the other on phase-space path integration. Leading quantum corrections to the classical Liouville propagator take the form of a time-dependent quantum spot. Its oscillatory structure depends on whether the underlying classical flow is elliptic or hyperbolic. It can be interpreted as the result of interference of a \emph{pair} of classical trajectories, indicating how quantum coherences are to be propagated semiclassically in phase space. The phase-space path-integral approach allows for a finer resolution of the quantum spot in terms of Airy functions.Comment: 4 pages, 3 figure

Damages caused by cotton rat, Sigmodon hispidus zanjonensis, on sugar cane in San Pedrosula, Honduras

Technical assistance was given to Compañía Azucarera Hondureña, S.A. (Agro-Industrial Co.), Honduras, Central America, to determine if a campaign against noxious rodents to agriculture crops was needed. Several trappings were carried out at different places using snap traps to determine the population structure of rodents associated with the crop, and live traps to determine the index or density of the Sigmodon hispidus rat population, which was identified as being responsible for the damage to sugarcane. Results were 43.24% adult males, 14.86% young males, 31.41% adult females, and 10.47% young females. Of the adult females captured, 54.83% were pregnant with an average of 3 to 4 embryos per rat. A control demonstration combat was carried out at one of the experimental stations with a bait prepared with 2% zinc phosphide in a place where it had been previously determined there was a population of 39 rats per hectare. After such control, the population was reduced to 18 rats per hectare, which represents an efficiency of 53.85%. An evaluation of damages was also measured at different places to determine the degree of loss caused by the rats, which proved to be 22.79% damage. The size of the sample was estimated in 3 samples per hectare, with a level of confidence of 95%

Pseudotyped Lentiviral Vectors: One Vector, Many Guises

Viruses have evolved specialized molecular mechanisms to transfer their genome efficiently into host cells. Viruses can be repurposed into viral vectors to achieve controlled gene transfer to desired cells. One of the most popular class of vectors, lentiviral vectors, transduce mammalian cells efficiently. Lentiviral vectors are pseudotyped with various heterologous viral envelopes to alter their tropism. While the most common example is the envelope glycoprotein from vesicular stomatitis virus (VSVG), many other viral proteins have also been used. Pseudotyping lentiviral vectors with a diverse set of naturally occurring or engineered viral envelopes has allowed targeted infection of specific cell types. Many exciting studies are further uncovering new specificities and shortcomings of pseudotyped lentiviral vectors. These studies will expand the toolbox to make lentiviral vectors that cater to the specific requirements of transduction. In this review, we provide a comprehensive overview of various viral envelope pseudotypes used with LVs, their specificity, advantages, and drawbacks

Exploring Network Analysis for Urban Planning and Disaster Risk Reduction in Informal Settlements: Cases From Honduras, Jamaica, and Peru

The work explores the use of street network analysis on informal settlements and discusses the potential and limitations of this methodology to advance disaster risk reduction and urban resilience. The urban network analysis tool is used to conduct graph analysis measures on street networks in three informal settlements in the LAC region: Portmore, Jamaica; Tegucigalpa, Honduras; and Lima, Peru. Authors incorporate risk variables identified by these communities and combine them with prospective scenarios in which street networks are strategically intervened to improve performance. Authors also compute one graph index named Reach centrality. Results are presented spatially through thematic maps, and statistically by plotting cumulative distributions. Findings show that centrality measures of settlements' networks helped identify key nodes or roads that may be critical for people's daily life after disasters, and strategic to improve accessibility. The proposed methodology shows potential to inform decisions on urban planning and disaster risk reduction