Poverty Traps

The understanding of why some countries fail to develop is one of the most intriguing and productive challenges for the modern theory of economic growth. Although many questions remains unanswered, the theory has gone a long way to explain and reveal many of the reasons underlying the persistence of poverty traps. Multiple causes, endogeneity and country-specific differences make it difficult to explain within a unified framework why some economies, caught in a vicious cycle, suffer from persistent underdevelopment

Electrostatic tailoring of magnetic interference in quantum point contact ballistic Josephson junctions

The magneto-electrostatic tailoring of the supercurrent in quantum point contact ballistic Josephson junctions is demonstrated. An etched InAs-based heterostructure is laterally contacted to superconducting niobium leads and the existence of two etched side gates permits, in combination with the application of a perpendicular magnetic field, to modify continuously the magnetic interference pattern by depleting the weak link. For wider junctions the supercurrent presents a Fraunhofer-like interference pattern with periodicity h/2e whereas by shrinking electrostatically the weak link, the periodicity evolves continuously to a monotonic decay. These devices represent novel tunable structures that might lead to the study of the elusive Majorana fermions.Comment: 4.5 pages, 4 color figure

Picocyanobacteria distribution in the Ebro Estuary (Spain)

The stratified estuary of the Ebro River is located on the Mediterranean coast of Spain. From samples obtained in 6 sampling campaigns between July 1999 and February 2000 from the last 18 km of Ebro River, the abundance of picocyanobacteria was estimated by epifluorescence microscopy. The abundance of picocyanobacteria reached 93.7 x106 cells L–1 in the river mouth (station R1) below the surface, in October 1999. In deeper layers of salt wedge area stations (near the river mouth), we could observe higher concentrations of marine cyanobacteria. This study offers comments about the abundance and distribution in cyanobacteria

On the structure of isothermal acoustic shocks under classical and artificial viscosity laws: Selected case studies

Assuming Newton's law of cooling, the propagation and structure of isothermal acoustic shocks are studied under four different viscosity laws. Employing both analytical and numerical methods, 1D traveling wave solutions for the velocity and density fields are derived and analyzed. For each viscosity law considered, expressions for both the shock thickness and the asymmetry metric are determined. And, to ensure that isothermal flow is achievable, upper bounds on the associated Mach number values are derived/computed using the isothermal version of the energy equation.Comment: 26 pages, 2 figures, journal articl

Device for dispersal of micrometer- and submicrometer-sized particles in vaccum

A simple, versatile device for dispersing micrometer‐ and submicrometer-sized particles in vacuum is described. The source allows control of particle size (0.5 μm≤l≤200 μm) and particle flux density up to roughly 107 cm−2 s−1. Several types of microparticles were successfully dispersed

Little-Parks effect in single YBaCuO sub-micron rings

The properties of single submicron high-temperature superconductor (HTS) rings are investigated. The Little-Parks effect is observed and is accompanied by an anomalous behavior of the magnetic dependence of the resistance, which we ascribe to non-uniform vorticity (superfluid angular momentum) within the ring arms. This effect is linked to the peculiar HTS-relationship between the values of the coherence length and the London penetration depth.Comment: 14 pages, 3 figure

Living on the Edge: Settlement Patterns by the Symbiotic Barnacle \u3cem\u3eXenobalanus globicipitis\u3c/em\u3e on Small Cetaceans

The highly specialized coronulid barnacle Xenobalanus globicipitis attaches exclusively on cetaceans worldwide, but little is known about the factors that drive the microhabitat patterns on its hosts. We investigate this issue based on data on occurrence, abundance, distribution, orientation, and size of X. globicipitis collected from 242 striped dolphins (Stenella coeruleoalba) that were stranded along the Mediterranean coast of Spain. Barnacles exclusively infested the fins, particularly along the trailing edge. Occurrence, abundance, and density of X. globicipitis were significantly higher, and barnacles were significantly larger, on the caudal fin than on the flippers and dorsal fin. Barnacles were found more frequently and in greater numbers on the dorsal rather than ventral side of the caudal fin and on the central third of dorsal and ventral fluke surfaces. Nearly all examined individuals attached with their cirral fan oriented opposite to the fluke edge. We suggest that X. globicipitis may chemically recognize dolphins as a substratum, but fins, particularly the flukes, are passively selected because of creation of vortices that increase contact of cyprids with skin and early survival of these larvae at the corresponding sites. Cyprids could actively select the trailing edge and orient with the cirri facing the main direction of flow. Attachment on the dorsal side of the flukes is likely associated with asymmetrical oscillation of the caudal fin, and the main presence on the central segment of the flukes could be related to suitable water flow conditions generated by fluke performance for both settlement and nutrient filtration

Post Activation Potentiation of Back Squat and Trap Bar Deadlift on Acute Sprint Performance

Please refer to the pdf version of the abstract located adjacent to the title