Fractality of certain quantum states

We prove the theorem announced in Phys. Rev. Lett. {\bf 85}:5022, 2001 concerning the existence and properties of fractal states for the Schr\"odinger equation in the infinite one-dimensional well.Comment: Latex2e with svjour clas

Crossover from Diffusive to Ballistic Transport in Periodic Quantum Maps

We derive an expression for the mean square displacement of a particle whose motion is governed by a uniform, periodic, quantum multi-baker map. The expression is a function of both time, $t$, and Planck's constant, $\hbar$, and allows a study of both the long time, $t\to\infty$, and semi-classical, $\hbar\to 0$, limits taken in either order. We evaluate the expression using random matrix theory as well as numerically, and observe good agreement between both sets of results. The long time limit shows that particle transport is generically ballistic, for any fixed value of Planck's constant. However, for fixed times, the semi-classical limit leads to diffusion. The mean square displacement for non-zero Planck's constant, and finite time, exhibits a crossover from diffusive to ballistic motion, with crossover time on the order of the inverse of Planck's constant. We argue, that these results are generic for a large class of 1D quantum random walks, similar to the quantum multi-baker, and that a sufficient condition for diffusion in the semi-classical limit is classically chaotic dynamics in each cell. Some connections between our work and the other literature on quantum random walks are discussed. These walks are of some interest in the theory of quantum computation.Comment: Final version to appear in Physica D, Proceedings of the International Workshop and Seminar on Microscopic Chaos and Transport in Many-Particle Systems, Dresden, 2002; corrected a minor error in section 3.1, new section 4.

Influence of the proximity and amount of human development and roads on the occurrence of the red imported fire ant in the lower Florida Keys

We examined the influence of both the proximity and extent of human developments and paved roads on the presence of the predatory, non-indigenous, red imported fire ant (Solenopsis invicta). This species was inadvertently introduced into the United States at the port of Mobile, Alabama, around 1930 and rapidly spread to many southeastern states, including Florida. More recently, S. invicta colonized the Florida Keys, an area with a high proportion of rare and endemic vertebrate and invertebrate species. We placed bait transects in transitional salt-marsh, pineland, and hardwood hammocks on 13 of the lower Florida Keys and compared habitat type, the shortest distance of the bait transect to a development or road, and area of development and roads 50, 70, 100, and 150 m around each bait transect for areas with and without red imported fire ants. Red imported fire ants were detected on 21 of the 80 transects and were equally abundant in all habitat types. While all of the development and road variables differed significantly between bait transects with and without red imported fire ants, transects that were closest to roads and that had the largest amount of development within a 150 m radii had the highest probability of presence of red imported fire ants. Recovery efforts for endangered species in areas invaded by red imported fire ants should include analyses of the cumulative impacts of roads and developments in areas near protected lands

An Assessment of the Academic Impact of Shock Society Members

Professional society membership enhances career development and productivity by offering opportunities for networking and learning about recent advances in the field. The quality and contribution of such societies can be measured in part through the academic productivity, career status, and funding success rates of their members. Here, using Scopus, NIH RePORTER, and departmental websites, we compare characteristics of the Shock Society membership to those of the top 55 NIH-funded American university and hospital-based departments of surgery. Shock Society members' mean number of publications, citations and H-indices were all significantly higher than those of non-members in surgery departments (P < 0.001). A higher percentage of members also have received funding from the NIH (42.5% vs. 18.5%, P < 0.001). Regression analysis indicated that members were more likely to have NIH funding compared with non-members (OR 1.46, 95% CI 1.12-1.916). Trauma surgeons belonging to the Shock Society had a higher number of publications and greater NIH funding than those who did not (130.4 vs. 42.7, P < 0.001; 40.4% vs. 8.5%, P < 0.001). Aggregate academic metrics from the Shock Society were superior to those of the Association for Academic Surgery and generally for the Society of University Surgeons as well. These data indicate that the Shock Society represents a highly academic and productive group of investigators. For surgery faculty, membership is associated with greater academic productivity and career advancement. While it is difficult to ascribe causation, certainly the Shock Society might positively influence careers for its members

Arte e trauma

Esse artigo é um extrato editado de Outsider art: Visionary Worlds and Trauma [Arte Outsider: mundos visionários e trauma], de Daniel Wojcik, University Press of Mississippi, 2016

Red Imported Fire Ants: Impact on Biodiversity

The red imported fire ant, Solenopsis invicta Buren (hereafter referred to as imported fire ant), long considered a regional problem, is receiving renewed attention nationwide, with infestations found in Arizona, Maryland, Nevada, New Mexico, and Virginia (Mitchell 1996). Recently, infestations discovered in several regions of California caused great public concern (Brennan 1999, Schrader 1999). Initially, infestations appeared to be isolated in almond groves in Kern County; presumably these infestations originated from bee hives transported interstate for the purpose of pollinating crops. Separately, ornamental plants arriving in Las Vegas, NV, were infested with fire ants, and records showed that the point of origin was a nursery in Orange County, CA. Further inspections revealed infestations in over 16,000 acres of Orange County. Finally, infestations were identified in some desert irrigated agricultural regions of the Coachella Valley in Riverside County, CA. Subsequently, a toll-free telephone number was established for reporting fire ant mounds in the state of California (800-491-1899)

Joint flow-seismic inversion for characterizing fractured reservoirs: theoretical approach and numerical modeling

Traditionally, seismic interpretation is performed without any account of the flow behavior. Here, we present a methodology to characterize fractured geologic media by integrating flow and seismic data. The key element of the proposed approach is the identification of the intimate relation between acoustic and flow responses of a fractured reservoir through the fracture compliance. By means of synthetic models, we show that: (1) owing to the strong (but highly uncertain) dependence of fracture permeability on fracture compliance, the modeled flow response in a fractured reservoir is highly sensitive to the geophysical interpretation; and (2) by incorporating flow data (well pressures and production curves) into the inversion workflow, we can simultaneously reduce the error in the seismic interpretation and improve predictions of the reservoir flow dynamics.Eni-MIT Energy Initiative Founding Member Progra