Quantum and classical solutions for free particle in wedge billiards

We have studied the quantum and classical solutions of a particle constrained to move inside a sector circular billiard with angle $\theta_w$ and its pacman complement with angle $2\pi-\theta_w$. In these billiards rotational invariance is broken and angular momentum is no longer a conserved quantum number. The "fractional" angular momentum quantum solutions are given in terms of Bessel functions of fractional order, with indices $\lambda_p={p\pi \over {\theta_w}}$, $p=1,2,...$ for the sector and $\mu_q={q\pi \over {2\pi - \theta_w}}$, $q=1,2...$ for the pacman. We derive a ``duality'' relation between both fractional indices given by $\lambda_p={{p\mu_q} \over {2\mu_q - q}}$ and $\mu_q = {{q\lambda_p} \over {2\lambda_p - p}}$. We find that the average of the angular momentum $\hat L_z$ is zero but the average of $\hat L^2_z$ has as eigenvalues $\lambda_p^2$ and $\mu_q^2$. We also make a connection of some classical solutions to their quantum wave eigenfunction counterparts.Comment: 10 pages and two PostScript figure

Coherent Exclusive Exponentiation CEEX: the Case of the Resonant e+ e- Collision

We present the first-order coherent exclusive exponentiation (CEEX) scheme, with the full control over spin polarization for all fermions. In particular it is applicable to difficult case of narrow resonances. The resulting spin amplitudes and the differential distributions are given in a form ready for their implementation in the Monte Carlo event generator. The initial-final state interferences are under control. The way is open to the use of the exact amplitudes for two and more hard photons, using Weyl-spinor techniques, without giving up the advantages of the exclusive exponentiation, of the Yennie-Frautschi-Suura type.Comment: 14 page

Full capacitance-matrix effects in driven Josephson-junction arrays

We study the dynamic response to external currents of periodic arrays of Josephson junctions, in a resistively capacitively shunted junction (RCSJ) model, including full capacitance-matrix effects}. We define and study three different models of the capacitance matrix $C_{\vec{r},\vec{r}'}$: Model A includes only mutual capacitances; Model B includes mutual and self capacitances, leading to exponential screening of the electrostatic fields; Model C includes a dense matrix $C_{\vec{r},\vec{r}'}$ that is constructed approximately from superposition of an exact analytic solution for the capacitance between two disks of finite radius and thickness. In the latter case the electrostatic fields decay algebraically. For comparison, we have also evaluated the full capacitance matrix using the MIT fastcap algorithm, good for small lattices, as well as a corresponding continuum effective-medium analytic evaluation of a finite voltage disk inside a zero-potential plane. In all cases the effective $C_{\vec{r},\vec{r}'}$ decays algebraically with distance, with different powers. We have then calculated current voltage characteristics for DC+AC currents for all models. We find that there are novel giant capacitive fractional steps in the I-V's for Models B and C, strongly dependent on the amount of screening involved. We find that these fractional steps are quantized in units inversely proportional to the lattice sizes and depend on the properties of $C_{\vec{r},\vec{r}'}$. We also show that the capacitive steps are not related to vortex oscillations but to localized screened phase-locking of a few rows in the lattice. The possible experimental relevance of these results is also discussed.Comment: 12 pages 18 Postscript figures, REVTEX style. Paper to appear in July 1, Vol. 58, Phys. Rev. B 1998 All PS figures include

Una metodología para identificación y análisis de sistemas de producción agropecuarios en áreas de pequeños productores.

Guía para el personal técnico de los Distritos de Transferencia de Tecnología del ICA para el diagnóstico de campo. En primer término se discute el concepto de los principios metodológicos que se utilizan en el desarrollo del trabajo para la identificación de sistemas de producción (conjunto, región, conjunto productivo, factores modificables e inmodificables, arreglos solos, en asocio, en relevo, intercalado y múltiple, sistema de producción, unidad de producción familiar y tecnología local de producción). Luego se describe la concatenación y la aplicación de los conceptos previamente definidos, para la conformación del cuerpo de la metodología de identificación de sistemas propiamente dicha. Se ofrecen algunas guías de análisis para la definición de recomendaciones técnicas en primera aproximación para los sistemas de producción prioritarios. Se define el programa de exploración y ajuste tecnológico para solucionar los problemas identificados en los sistemas de producción. Para facilitar un mejor entendimiento, el documento se divide en dos secciones: en la primera se hace referencia a los sistemas agrícolas y en la segunda a los sistemas pecuario

SEROLOGICAL EVIDENCE OF THE PRESENCE OF CANINE HERPES VIRUS TYPE 1 IN LIMA PROVINCE

El Virus Herpes Canino tipo 1 (VHC-1) es responsable de la enfermedad hemorrágica canina en cachorros menores de cuatro semanas de vida y de algunos problemas reproductivos en perras adultas. En el Perú, la enfermedad no ha sido reportada, aunque existen hallazgos que sugieren su presencia. El objetivo del presente estudio fue demostrar la presencia de anticuerpos contra el VHC-1 entre la población canina con antecedentes asociados a problemas reproductivos. Se recolectaron muestras de sangre de 28 animales procedentes de siete distritos de la provincia de Lima que tuvieron algún antecedente relacionado a problemas reproductivos o mortalidad neonatal. Las muestras fueron analizadas con la prueba de inmunofluorescencia indirecta (IFI) donde nueve canes (32 ± 17%) resultaron positivos.The canine Herpesvirus type 1 (CHV-1) is responsible for the canine hemorrhagic disease in puppies aged less than four weeks and for some reproductive problems in adult bitches. In Peru, the disease has been not reported, although there are findings suggesting its presence. Thus, the aim of this study was to show the presence of antibodies against CHV-1 among the canine population associated with history of reproductive problems. Blood samples from 28 animals belonging to seven districts of the province of Lima were collected. These dogs had a history of reproductive problems or neonatal mortality. Samples were submited to the indirect immunofluorescense test (IFAT), and nine of them (32 ± 17%) were positive to the test

Transcriptome responses to Ralstonia solanacearum infection in the roots of the wild potato Solanum commersonii

Background: Solanum commersonii is a wild potato species that exhibits high tolerance to both biotic and abiotic stresses and has been used as a source of genes for introgression into cultivated potato. Among the interesting features of S. commersonii is resistance to the bacterial wilt caused by Ralstonia solanacearum, one of the most devastating bacterial diseases of crops. Results: In this study, we used deep sequencing of S. commersonii RNA (RNA-seq) to analyze the below-ground plant transcriptional responses to R. solanacearum. While a majority of S. commersonii RNA-seq reads could be aligned to the Solanum tuberosum Group Phureja DM reference genome sequence, we identified 2,978 S. commersonii novel transcripts through assembly of unaligned S. commersonii RNA-seq reads. We also used RNA-seq to study gene expression in pathogen-challenged roots of S. commersonii accessions resistant (F118) and susceptible (F97) to the pathogen. Expression profiles obtained from read mapping to the S. tuberosum reference genome and the S. commersonii novel transcripts revealed a differential response to the pathogen in the two accessions, with 221 (F118) and 644 (F97) differentially expressed genes including S. commersonii novel transcripts in the resistant and susceptible genotypes. Interestingly, 22.6% of the F118 and 12.8% of the F97 differentially expressed genes had been previously identified as responsive to biotic stresses and half of those up-regulated in both accessions had been involved in plant pathogen responses. Finally, we compared two different methods to eliminate ribosomal RNA from the plant RNA samples in order to allow dual mapping of RNAseq reads to the host and pathogen genomes and provide insights on the advantages and limitations of each technique. Conclusions: Our work catalogues the S. commersonii transcriptome and strengthens the notion that this species encodes specific genes that are differentially expressed to respond to bacterial wilt. In addition, a high proportion of S. commersonii-specific transcripts were altered by R. solanacearum only in F118 accession, while phythormone-related genes were highly induced in F97, suggesting a markedly different response to the pathogen in the two plant accessions studied

Elementary excitation in the spin-stripe phase in quantum chains

Elementary excitations in condensed matter capture the complex many-body dynamics of interacting basic entities in a simple quasiparticle picture. In magnetic systems the most established quasiparticles are magnons, collective excitations that reside in ordered spin structures, and spinons, their fractional counterparts that emerge in disordered, yet correlated spin states. Here we report on the discovery of elementary excitation inherent to spin-stripe order that represents a bound state of two phason quasiparticles, resulting in a wiggling-like motion of the magnetic moments. We observe these excitations, which we dub “wigglons”, in the frustrated zigzag spin-1/2 chain compound β-TeVO4, where they give rise to unusual low-frequency spin dynamics in the spin-stripe phase. This result provides insights into the stripe physics of strongly-correlated electron systems

Demand in the electricity market: analysis using big data

The traditional business model of energy companies is changing in recent years. The introduction of smart meters has led to an exponential increase in the volume of data available, and their analysis can help find consumption patterns among electric customers to reduce costs and protect the environment. Power plants generate electricity to cover peak consumption at specific times. A set of techniques called “demand response” tries to solve this problem using artificial intelligence proposals. This document proposes a method for processing large volumes of data such as those generated by smart meters. Both for the preprocessing and for the optimization and realization of this analysis big data techniques are used. Specifically, a distributed version of the k-means algorithm and several indices of internal validation of clustering for big data in Spark. The source data correspond to the consumption of electric customers in Bogota, Colombia during the year 2018. The analysis carried out in this study about consumers helps their characterization. This greater knowledge about consumer habits and types of customers can enhance the work of utilities

Similarities between the lipid proile of Mexican patients with lupus and the general population

Premature cardiovascular events have been observed in systemic lupus erythematosus (SLE) patients, but the reason for this accelerated process is still debatable; although traditional risk factors are more prevalent in such patients than in the general population, the do not seem to fully explain that enhanced risk. One of the most important conditions is a proatherogenic lipid proile. There is not enough data about it in Mexican SLE patients. Objective: To establish the differences in the lipid proiles between Mexican patients with SLE and the general population. Material and methods: Observational, transversal, descriptive and comparative study, between SLE patients and age-sex-matched healthy volunteers. We performed a full lipid proile (by spectrophotometry) 14 hours of fast. The results obtained were analyzed by the statistical program SPSS® Statistics version 17. Results: We studied the full lipid proiles of 138 subjects, 69 with a diagnosis of SLE and 69 agesex- matched healthy volunteers; 95.7% were females and 4.3% males. Average age was 30 years; average body mass index (BMI) 25.96 ± 5.96 kg/m² in SLE patients and 26.72 ± 4.36 kg/m² in the control group (p = 0.396). Average of total cholesterol 156 mg/dl in the SLE patients and 169.4 mg/dl in the control group (p =0.028); average of low density lipoprotein (LDL) cholesterol 85.27 mg/dl in the SLE patients and 97.57 mg/dl in the control group (p = 0.023). Conclusions: We did not ind statistical differences in the lipid proiles among patients and healthy volunteers, which could explain increased cardiovascular morbidity and mortality observed in SLE patient