Error Propagation in the Hypercycle

We study analytically the steady-state regime of a network of n error-prone self-replicating templates forming an asymmetric hypercycle and its error tail. We show that the existence of a master template with a higher non-catalyzed self-replicative productivity, a, than the error tail ensures the stability of chains in which m<n-1 templates coexist with the master species. The stability of these chains against the error tail is guaranteed for catalytic coupling strengths (K) of order of a. We find that the hypercycle becomes more stable than the chains only for K of order of a2. Furthermore, we show that the minimal replication accuracy per template needed to maintain the hypercycle, the so-called error threshold, vanishes like sqrt(n/K) for large K and n<=4

Determining R-parity violating parameters from neutrino and LHC data

In supersymmetric models neutrino data can be explained by R-parity violating operators which violate lepton number by one unit. The so called bilinear model can account for the observed neutrino data and predicts at the same time several decay properties of the lightest supersymmetric particle. In this paper we discuss the expected precision to determine these parameters by combining neutrino and LHC data and discuss the most important observables. We show that one can expect a rather accurate determination of the underlying R-parity parameters assuming mSUGRA relations between the R-parity conserving ones and discuss briefly also the general MSSM as well as the expected accuracies in case of a prospective e+ e- linear collider. An important observation is that several parameters can only be determined up to relative signs or more generally relative phases.Comment: 13 pages, 13 figure

The PMS project: Poor Man's Supercomputer

We briefly describe the Poor Man's Supercomputer (PMS) project carried out at Eotvos University, Budapest. The goal was to develop a cost effective, scalable, fast parallel computer to perform numerical calculations of physical problems that can be implemented on a lattice with nearest neighbour interactions. To this end we developed the PMS architecture using PC components and designed a special, low cost communication hardware and the driver software for Linux OS. Our first implementation of PMS includes 32 nodes (PMS1). The performance of PMS1 was tested by Lattice Gauge Theory simulations. Using SU(3) pure gauge theory or bosonic MSSM on PMS1 we obtained 3$/Mflop and 0.45$Mflop price-to-sustained performance for double and single precision operations, respectively. The design of the special hardware and the communication driver are freely available upon request for non-profit organizations.Comment: Latex, 13 pages, 6 figures included, minor additions, typos correcte

Tomato growth and dry matter partitioning as a function of the irrigation water quality.

Neste estudo, foram avaliados o crescimento e a partição de matéria seca do tomateiro industrial cv IPA 6, cultivado sob irrigação com águas de diferentes condutividades elétricas (ECw) e proporções de sódio, em um delineamento fatorial 5x2, inteiramente casualizado. As mudas foram transplantadas para rizotrons e irrigadas diariamente, sendo as matérias secas da haste, ramos, inflorescências e frutos determinadas no final do ciclo da cultura. O solo foi retirado dos rizotrons em intervalos de 15 cm de profundidade, lavado e peneirado para determinação da matéria seca das raízes em camada do solo. A matéria seca da parte aérea foi reduzida em 6,9% por incremento unitário da salinidade

Sistema de Controle da Pesca de Mato Grosso do Sul SCPESCA/MS - 9 - 2002.

Neste boletim encontram-se as informações sobre a pesca profissional e esportiva coletadas e analisadas pelo Sistema de Controle da Pesca de Mato Grosso do Sul (SCPESCA/MS), para o ano de 2002. Os dados obtidos foram provenientes do pescado capturado em toda a Bacia do Alto Paraguai em Mato Grosso do Sul e vistoriado pela Polícia Militar Ambiental/MS. Foi registrado um total de 686 t de pescado, do qual 312 t (45%) foram capturados pela pesca profissional e 374 t (55%) pela pesca esportiva. As espécies mais capturadas foram pintado Pseudoplatystoma corruscans (145 t, 27%), pacu Piaractus mesopotamicus (125 t, 24%), cachara Pseudoplatystoma fasciatum (54 t, 10%) e piavuçu Leporinus macrocephalus (41 t, 8%). Os rios que mais contribuíram foram Paraguai (253 t, 48%) e Miranda (125 t, 24%). Um total de 29.683 pescadores esportivos visitaram o Estado, provenientes, principalmente, de São Paulo (62%) com pico de ocorrência no mês de setembro. O número total de pescadores profissionais registrados foi de 1.272. Em mediana, mensalmente, os pescadores profissionais realizaram viagens com duração de 8 a 12 dias capturando entre 61,2 e 100,3 kg/pescador.viagem, com rendimento entre 7,35 e 13,22 kg/pescador.dia. Os pescadores esportivos, por sua vez, realizaram viagens com duração de 4 a 5 dias capturando entre 9,0 e 13,2 kg/pescador.viagem, com rendimento entre 2,12 e 2,97 kg/pescador.dia. De maneira geral, os dados de 2002 indicaram a mesma tendência observada nos anos anteriores em relação à diminuição na captura do dourado Salminus maxillosus pela pesca total, o que levou ao aumento do tamanho mínimo de captura para esta espécie, a vigorar a partir de 2004.bitstream/item/37403/1/BP47.pd

Electron Probe Microanalysis of the Otolithic Membrane. A Methodological and Quantitative Study

The effect of tissue preparation on calcium and potassium weight percents in the otoconial layer in the utricle and saccule was studied in four groups of OF1 mice with electron probe X-ray microanalysis. Glutaraldehyde and freeze-drying, glutaraldehyde and air-drying, air-drying, and cryo-fixation and freeze-drying were compared. Ca and K changed significantly in the utricle depending on the method used (P \u3c 0.001), and K changed significantly in the saccule (P \u3c 0.001 ). We chose cryo-fixation with freeze-drying for the quantitative analysis of the otolithic membrane because this method provided the highest values of Ca and K with minimum loss of Ca and K . Microcrystalline salt standards mounted on scanning electron microscopy holders were used for the quantification of Ca and K by the peak-to-local-background (P/B) ratio method. The P/B ratio in standards with reproducible results, when plotted against weight percent, gave a straight line for Ca (r = 0.99, P \u3c 0.001) and K (r = 0.98, P \u3c 0.001). The Ca and K weight percents in otoconia showed similar frequency distributions in the utricle and saccule

Impacts from the implementation of the ISO 22000

Purpose: The main purpose of this article is to assort different impacts of the ISO 22000 implementation considering internal or external impacts, positive or negative impacts. It also intends to provide a worldwide overview on the topic, to distinguish companies from different sectors and to gather different methodologies that are used in previously published articles related with this implementation. Design/methodology/approach- Different articles of the ISO 22000 implementation from different countries were gathered and singled out according to the information that was provided. The information of interest was analyzed and rewritten according to the initially established categories. Findings- The results from several studies, researches and points of view from different authors show that the ISO 22000 implementation carries positive impacts. Negative impacts are hard to find. Most of the impacts are directly related to the organizations themselves, hence being internal impacts. Studies are mainly carried out with the help of questionnaires that are presented to the companies. Research limitations/implications- The main goal was to come across different impacts and classify them either as positive and negative or internal and external. However, its unusual to find authors that consider negative impacts from the ISO 22000 implementation. Also, external impacts are not so common. Originality/value- This article mainly highlights the ISO 22000 implementation positive impacts in worldwide organizations. It summarizes the different countries views towards Food Safety Management Systems (FSMS) and how they affect the performance of their companies.U.Porto -Universidade do Porto(undefined)info:eu-repo/semantics/publishedVersio

Kalman Filtering in the Air Quality Monitoring

Data assimilation is a process where an improved prediction is obtained from a weighted combination between experimental measurements and mathematical model data. In the present work this procedure is applied to pollutant atmospheric dispersion by using a Kalman filter (KF). This is interesting approach, because the KF gives an output in which the balance between the data from the diffusion model and the experimental data is done automaticaly, through the Kalman gain. In addition, the Kalman filter computes the propagation of the error