Search results for "ratio [mass spectrum]"

Soil fungal community composition does not alter along a latitudinal gradient through the maritime and sub-Antarctic

2012

We investigated the relationships between fungal community composition, latitude and a range of physicochemical parameters in 58 soils sampled from a 2370 km latitudinal gradient between South Georgia (54 S, 38 W) in the sub-Antarctic and Mars Oasis (72 S, 68 W) on Alexander Island in the southern maritime Antarctic. Our study, which is based on approximately ten times the number of samples used in previous similar studies, indicates that latitude and its associated environmental parameters are not related to fungal community composition. Significant changes in the composition of soil fungal communities were observed in relation to gradients of the ratio of total organic carbon to nitrogen,…

Hypothesis testing for Panels of Semi-Markov Processes with parametric sojourn time distributions

2022

This work deals with the asymptotic properties of maximum likelihood estimators for semi-Markov processes with parametric sojourn time distributions. It is motivated by the comparison, via a two-sample test procedure, of the distribution of two panels of qualitative trajectories modeled by semi-Markov processes and observed over a random number of transitions. Considering first one panel of growing size, we derive, under classical conditions, the convergence in probability of the estimators of the transition probabilities and the parameters of the sojourn time distributions as well as their asymptotic normality. We then consider panels of semi-Markov processes drawn from two different popul…

Gli uccelli delle isole circumsiciliane

2015

Gli autori sintetizzano tutte le informazioni bibliografiche e inedite sulle specie che sino al 30 agosto 2015 sono state contattate almeno una volta nelle 14 isole circumsiciliane (Eolie, Ustica, Egadi, Pantelleria e Pelagie), confrontando alla fine la lista complessiva con quella delle isole Maltesi. In totale sono ad oggi note 434 specie (isole Maltesi incluse); molte di esse hanno mostrato nel corso dei secoli una notevole capacità di colonizzazione, fluttuando nel tempo o addirittura estinguendosi e ricolonizzando alcune isole. Questi piccoli territori in mezzo al mare rappresentano ottimi siti di controllo dell’andamento delle migrazioni nel corso dei decenni; alcune specie hanno chia…

Real-Time Detection of Incipient Inter-Turn Short Circuit and Sensor Faults in Permanent Magnet Synchronous Motor Drives Based on Generalized Likelih…

2022

This paper presents a robust model-based technique to detect multiple faults in permanent magnet synchronous motors (PMSMs), namely inter-turn short circuit (ITSC) and encoder faults. The proposed model is based on a structural analysis, which uses the dynamic mathematical model of a PMSM in an abc frame to evaluate the system’s structural model in matrix form. The just-determined and over-determined parts of the system are separated by a Dulmage–Mendelsohn decomposition tool. Subsequently, the analytical redundant relations obtained using the over-determined part of the system are used to form smaller redundant testable sub-models based on the number of defined fault terms. Furthermore, fo…

The sicilian cooperative system of wine production: the strategic choices and performance analyses of a case study

2020

Purpose The purpose of this paper is to verify whether, besides the traditional organisational models mainly implemented by wine-making cooperatives, more modern and hybrid organisational forms can be profitably applied within an increasingly competitive wine market. Design/methodology/approach The study outlined in this paper deployed a mixed method. Specifically, an archived analysis, a survey and a descriptive case study (including visits, interviews and documentary analysis) were the methodological techniques used in this study, which were “in series but integrated” between themselves. In this paper, the landscape of Sicilian wine cooperatives is described by collating and processing d…

Statistical properties of the capacity of Rice channels with MRC and EGC

2009

In this paper, we have studied the statistical properties of the capacity of Rice channels for both maximal ratio combining (MRC) and equal gain combining (EGC) schemes. We have analyzed the effect of the number of diversity branches and the amplitude of the line-of-sight (LOS) components in the diversity branches on the statistics of the channel capacity. Specifically, we have derived analytical expressions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the capacity of Rice channels when using MRC and EGC. It is observed that if the number of diversity branches or the amplitude of the LOS…

Cytokines gene expression in the tunica albuginea in patients with Peyronie’s disease. Pilot study with a control group

2011

INTRODUCTION: We decided to conduct a study to investigate the presence of cytokines in the albuginea of subjects with Peyronie's disease (PD). Cytokines, as responsible for intercellular communication, maybe involved in the pathogenesis of the disease. The identification of one or more involved cytokines may, in fact, be useful in the pharmacological treatment with biologic drugs that are able to interfere with specific cytokines. MATERIALS AND METHODS: Between January 2009 and Decembre 2010 at the Clinic of Urological outpatients clinic of the Policlinico of Palermo were recruited 20 subjects with PD, mean age 62.3 years (range 51-70) and 8 subjects with congenital recurvatum penis (mean …

Trattamento induratio penis plastica: benefici e svantaggi dell'extra-corporeal shock therapy (ESWT). Studio prospettico randomizzato v/s placebo.

2011

Individual- and group-level sex ratios under local mate competition : consequences of infanticide and reproductive dominance

2023

Extremely female-biased sex ratios of parasitoid wasps in multiple-foundress groups challenges evolutionary theory which predicts diminishing bias as foundress numbers increase. Recent theory based on foundress cooperation has achieved qualitative rather than quantitative success in explaining bias among parasitoids in the genus Sclerodermus. Here, we develop an explanation, expanding the theory of local mate competition, based on the observation that male production seems dominated by some foundresses within groups. Two sex ratio effects arise from such reproductive dominance: an immediate effect via suppression of male production, and a long-term evolutionary response to reproductive skew…

The growth of Finnish software companies in 2008-2011 : empirical investigation of financial ratios as the determinants of growth

2014

The purpose of this study is to examine the relation of growth and the financial ratios of a company. The theoretical portion of the study focuses on the concept of growth in entrepreneurship theory. The empirical portion consists of examination of the financial ratios of 162 Finnish software companies in 2008-2011 by means of quantitative analysis methods. Statistical analysis methods, including analysis of variance, correlation and regression analysis, are used in the analysis. The objective of the study is to reveal how growth affects the financial ratios of a company and which ratios can be used to predict growth. The effects of companies’ age, geographical location and industrial class…