Search results for "parametri"

Providing insights into browntail moth local outbreaks by combining life table data and semi-parametric statistics

2011

1. Life table studies have been an essential tool for the comprehension of insect population dynamics, although their use has been methodologically biased by a primary focus on mortality factors, especially natural enemies. Thus, studies in natural populations may relegate important mortality sources to the ‘unknown’ or ‘residual’ mortality categories. To overcome this limitation, life tables may be complemented by combining them with other approaches. 2. The aim of the present study was to provide insights into browntail moth Euproctis chrysorrhoea L. (Lepidoptera: Lymantriidae) local outbreaks by combining life table data and statistical modelling. First, E. chrysorrhoea population densit…

Modelling drift of pelagic offspring: the importance of egg surveys in providing a realistic model initialization

2015

Abstract Having valid information about the location and dynamics of biological processes is important for coastal management. In this context modelling, the pelagic drift of early life stages has been shown to be an important tool for understanding the spatial scale of population dynamics in marine systems. Often simulated particles are released in hypothetical quantities at assumed spawning grounds with no or few field data to guide the model parametrization. In this study, we combine high-resolution field data and state-of-the-art oceanographic modelling and use a probabilistic approach to construct kernel density distributions of the dispersal of pelagic fish eggs. Specifically, the pot…

Cardiac changes in subclinical and overt hyperthyroid women: retrospective study

2003

This retrospective and descriptive 4-year study was undertaken to describe cardiac changes in subclinical and overt hyperthyroidism.We revised the charts of 386 consecutive cardiopathic women whose blood samples were referred to the Radioimmunoassay Laboratory to evaluate thyroid function from 1 January 1997 through 31 December 2000.After excluding women because euthyroid or hypothyroid, or taking amiodarone and women with hypertension, rheumatic disease, myocardial infarction, a total of 31 hyperthyroid women were thus selected for the study: 19 with subclinical hyperthyroidism and 12 with overt hyperthyroidism. The prevalence of atrial fibrillation did not differ between subclinical (48%)…

Ovarian size and blood flow in women with polycystic ovary syndrome (PCOS) and their correlations with some endocrine parameters

2005

Objective: To determine how common polycystic ovarian morphology may be in women given the clinical diagnosis of polycystic ovary syndrome (PCOS) based on chronic anovulation and hyperandrogenism and whether certain hormonal factors correlate with ovarian morphology and blood flow. Design: Prospective study. Setting: Two academic endocrinology centers in Italy. Patient(s): Three hundred twenty-six women with PCOS and 50 age-matched and weight-matched ovulatory women. Intervention(s): Ultrasound assessment of ovarian morphology in patients and controls and ovarian blood flow and fasting hormone levels in a subset of 50 patients and matched controls. Main Outcome Measure(s): Ovarian morpholog…

Item Response Trees: a recommended method for analyzing categorical data in behavioral studies

2015

Behavioral data are notable for presenting challenges to their statistical analysis, often due to the difficulties in measuring behavior on a quantitative scale. Instead, a range of qualitative alternative responses is recorded. These can often be understood as the outcome of a sequence of binary decisions. For example, faced by a predator, an individual may decide to flee or stay. If it stays, it may decide to freeze or display a threat and if it displays a threat, it may choose from several alternative forms of display. Here we argue that instead of being analyzed using traditional nonparametric statistics or a series of separate analyses split by response categories, this kind of data ca…

Análisis y valoración de los sistemas de evaluación de suelos en España. Evolución, tendencias actuales y perspectivas futuras

1997

23 páginas, 5 cuadros.

Applicazione di tecniche di Remote Sensing: stima di parametri biofisici della vegetazione e dell’evapotraspirazione effettiva

2009

Influenza di parametri fermentativi sulla composizione di vini Catarratto

2011

Restituzioni omografiche di finte cupole: la cupola di Santa Maria dei Rimedi a Palermo

2016

Nel vasto repertorio siciliano delle prospettive solide, un ruolo di spicco è ricoperto da un esempio unico di realizzazione di finta prospettiva di cupola sferica su copertura ad arco ribassato, ricavata sull’incrocio del transetto con la navata centrale nella chiesa di Santa Maria dei Rimedi a Palermo. L’unicità di quest’opera sta nella geometria reale della cupola ribassata. Infatti gli esempi più diffusi di finte cupole in Sicilia sono realizzati su soffitti piani lignei o in calcestruzzo. In Appendice 1 si potrà consultare il repertorio delle finte cupole esistenti in Sicilia per la cui stesura ci si è avvalsi degli studi condotti dall’architetto Giuseppe Ingaglio nell’ambito della sua…

Elastīgais parametriskais modelis izdzīvošanas datiem ar konkurējošiem riskiem

2015

Konkurējošie riski ir izplatīta parādība izdzīvošanas analīzē. Tie rodas, kad subjekts atrodas vairāku savstarpēji izslēdzošu notikumu riska zonā. Populārākā metode, pētot šāda veida datus, ir Deivida Koksa semi-parametriskā modeļa izmantošana. Darbā ir aplūkots alternatīvais variants izdzīvošanas datiem ar konkurējošiem riskiem – elastīgais parametriskais modelis, kas sniedz gludus novērtējumus galvenajiem raksturlielumiem – konkrēto cēloņu riskam un kumulatīvo biežumu funkcijai. Turklāt, izmantojot šo modeli, ir viegli iekļaut no laika atkarīgus ietekmējošos mainīgos. Darbā tiek aprakstīta konkurējošo risku elastīgā parametriskā modeļa būtība, un metode ir salīdzināta ar Koksa modeli. Ir …