The importance of bank seniority for relationship lending

The authors examine two aspects of a bank's interaction with its borrowers--the relative priority of bank debt and the role of banks as "relationship lenders." They show that making the bank senior improves its incentives to build a relationship with the firm, thereby fulfilling an important function of intermediated debt.Bank loans

Parking functions, labeled trees and DCJ sorting scenarios

In genome rearrangement theory, one of the elusive questions raised in recent years is the enumeration of rearrangement scenarios between two genomes. This problem is related to the uniform generation of rearrangement scenarios, and the derivation of tests of statistical significance of the properties of these scenarios. Here we give an exact formula for the number of double-cut-and-join (DCJ) rearrangement scenarios of co-tailed genomes. We also construct effective bijections between the set of scenarios that sort a cycle and well studied combinatorial objects such as parking functions and labeled trees.Comment: 12 pages, 3 figure

Variation of Micronutrients in Pumpkin FruitVarieties Grown Within the Lake Victoria Basin

Food shortage is a common occurrence in the developing countries. The shortage is emancipated in both low quantity and poor quality resulting in deficiency based diseases. The fact that pumpkins have an easy production (3-4 month), long shelf life (over six month) and therefore available, should increase their likelihood incorporation in the diet. The study set out to establish the varieties and levels of micronutrients in the fruits of the pumpkins grown by small holder farmers in four districts of Busia, Gucha, Jinja and Tarime within the Lake Victoria Basin. A questionnaire was administered to determine information on the varieties. The levels of ?-carotene, ?-tocopherol and the B-complex vitamins were determined with RP HPLC. Vitamin C was analysed by titration while AAS was used for the analysis of trace elements (zinc, iron and selenium). Standards were run and calibration curve equations with 0.955 ? R2 ? 0.999 used to calculate the concentrations.  Three species of pumpkins Cucurbita maxima, Cucurbitapepo and Cucurbitamoschata were widely distributed. Ten different varieties were sampled. The levels of micronutrients in different varieties (Fruits) showed significant differences that could not be accounted for by chance. At 95 % confidence limit, moisture (p = 0.001), ?-carotene (p = 0.002), thiamine (p = 0.000), riboflavin (p = 0.001), niacin (p = 0.009) and pyridoxine (p = 0.000) varied significantly. Further comparison of the samples from each district equally showed significant differences (p < 0.05) in all micronutrients except vitamin C (p = 0.08) and selenium (p = 0.447) levels. These results indicate non universality in levels of micronutrients in different varieties and between locations enhancing the need for focusing on those superior varieties (like the banana variety) as established in this study. From the levels of the micronutrients (?-carotene 2.220-2.670 mg / 100 g, zinc 0.986-1.728 mg / 100g, iron 2.16-1.68 mg / 100g) established, it is appropriate to popularize the utilization of pumpkins as a conventional rich food source to supplement the traditional cereal based diets aimed at combating the problem of food shortages and malnutrition in the Lake Victoria Basin and developing countries in general

Pareto's Law of Income Distribution: Evidence for Germany, the United Kingdom, and the United States

We analyze three sets of income data: the US Panel Study of Income Dynamics PSID), the British Household Panel Survey (BHPS), and the German Socio-Economic Panel (GSOEP). It is shown that the empirical income distribution is consistent with a two-parameter lognormal function for the low-middle income group (97%-99% of the population), and with a Pareto or power law function for the high income group (1%-3% of the population). This mixture of two qualitatively different analytical distributions seems stable over the years covered by our data sets, although their parameters significantly change in time. It is also found that the probability density of income growth rates almost has the form of an exponential function.Comment: Latex2e v1.6; 16 pages with 5 figure

A planar diagram approach to the correlation problem

We transpose an idea of 't Hooft from its context of Yang and Mills' theory of strongly interacting quarks to that of strongly correlated electrons in transition metal oxides and show that a Hubbard model of N interacting electron species reduces, to leading orders in N, to a sum of almost planar diagrams. The resulting generating functional and integral equations are very similar to those of the FLEX approximation of Bickers and Scalapino. This adds the Hubbard model at large N to the list of solvable models of strongly correlated electrons. PACS Numbers: 71.27.+a 71.10.-w 71.10.FdComment: revtex, 5 pages, with 3 eps figure

A Simple Model of Liquid-liquid Phase Transitions

In recent years, a second fluid-fluid phase transition has been reported in several materials at pressures far above the usual liquid-gas phase transition. In this paper, we introduce a new model of this behavior based on the Lennard-Jones interaction with a modification to mimic the different kinds of short-range orientational order in complex materials. We have done Monte Carlo studies of this model that clearly demonstrate the existence of a second first-order fluid-fluid phase transition between high- and low-density liquid phases

Spatio-temporal dynamics of quantum-well excitons

We investigate the lateral transport of excitons in ZnSe quantum wells by using time-resolved micro-photoluminescence enhanced by the introduction of a solid immersion lens. The spatial and temporal resolutions are 200 nm and 5 ps, respectively. Strong deviation from classical diffusion is observed up to 400 ps. This feature is attributed to the hot-exciton effects, consistent with previous experiments under cw excitation. The coupled transport-relaxation process of hot excitons is modelled by Monte Carlo simulation. We prove that two basic assumptions typically accepted in photoluminescence investigations on excitonic transport, namely (i) the classical diffusion model as well as (ii) the equivalence between the temporal and spatial evolution of the exciton population and of the measured photoluminescence, are not valid for low-temperature experiments.Comment: 8 pages, 6 figure

On the Behavior of the Effective QCD Coupling alpha_tau(s) at Low Scales

The hadronic decays of the tau lepton can be used to determine the effective charge alpha_tau(m^2_tau') for a hypothetical tau-lepton with mass in the range 0 < m_tau' < m_tau. This definition provides a fundamental definition of the QCD coupling at low mass scales. We study the behavior of alpha_tau at low mass scales directly from first principles and without any renormalization-scheme dependence by looking at the experimental data from the OPAL Collaboration. The results are consistent with the freezing of the physical coupling at mass scales s = m^2_tau' of order 1 GeV^2 with a magnitude alpha_tau ~ 0.9 +/- 0.1.Comment: 15 pages, 4 figures, submitted to Physical Review D, added references, some text added, no results nor figures change

Operation of an optoelectronic crossbar switch containing a terabit-per-second free-space optical interconnect

The experimental operation of a terabit-per-second scale optoelectronic connection to a silicon very-large-scale-integrated circuit is described. A demonstrator system, in the form of an optoelectronic crossbar switch, has been constructed as a technology test bed. The assembly and testing of the components making up the system, including a flip-chipped InGaAs-GaAs optical interface chip, are reported. Using optical inputs to the electronic switching chip, single-channel routing of data through the system at the design rate of 250 Mb/s (without internal fan-out) was achieved. With 4000 optical inputs, this corresponds to a potential aggregate data input of a terabit per second into the single 14.6 /spl times/ 15.6 mm CMOS chip. In addition 50-Mb/s data rates were switched utilizing the full internal optical fan-out included in the system to complete the required connectivity. This simultaneous input of data across the chip corresponds to an aggregate data input of 0.2 Tb/s. The experimental system also utilized optical distribution of clock signals across the CMOS chip