Search results for "MORPHOLOGY"
showing 10 items of 1425 documents
Classification of Primula sect. Auricula (Primulaceae) based on two molecular data sets (ITS, AFLPs), morphology and geographical distribution
2004
On the basis of the study of c. 1100 herbarium specimens, field observations and molecular (ITS, AFLPs) evidence, Primula sect. Auricula is classified into two subsections, 25 species and six subspecies. Primula auricula L. ssp. widmerae (Pax) L. B. Zhang stat. nov., P. auricula Linn. ssp. tatriaca L. B. Zhang ssp. nov., and P. latifolia Lapeyr. ssp. cynoglossifolia (Widmer) L. B. Zhang stat. nov. are newly described or combined; P. auricula s.l. is divided into two species: P. auricula Linn. and P. balbisii Lehm., representing the northern and the southern populations of P. auricula s.l. resolved in the molecular study, respectively; P. cottia Widmer and P. balbisii Lehm. are recovered fro…
Life in suspension and its impact on phytoplankton morphology: an homage to Colin S. Reynolds
2020
The amazing morphological diversity of phytoplankton has to be considered an evolutionarily driven compendium of strategies to cope with the strong variability and unpredictability of the pelagic environment. Phytoplankton collects unicellular and colonial photosynthetic organisms adapted to live in apparent suspension in turbulent water masses. Turbulence represents a key driver of phytoplankton dynamics in all aquatic ecosystems and phytoplankton morphological variability is the evolutionary response of this group of photosynthetic organisms to the temporal and spatial scales of variability of turbulence. This paper reviews the existing literature on the effects exerted by turbulence on p…
Stima della potenza cinetica della precipitazione a partire da osservazioni disdrometriche di distribuzioni dimensionali delle gocce di pioggia
2011
Lo studio del distacco delle particelle di suolo operato dalla pioggia richiede la conoscenza delle caratteristiche erosive della precipitazione. Nella memoria, dopo aver richiamato i presupposti teorici della legge di Ulbrich e le espressioni della potenza cinetica da essa deducibili, viene presentata una verifica di applicabilita della suddetta distribuzione teorica sulla base delle distribuzioni dimensionali delle gocce di pioggia rilevate mediante un disdrometro ottico installato presso la sezione Idraulica del Dipartimento dei Sistemi Agro-Ambientali dell’Universita di Palermo. Viene proposta, infine, una verifica sperimentale dell’equazione di Wischmeier e Smith per il calcolo della p…
The Complex Morphology of the X-ray and Optical Emission from HH 154: The Pulsed Jet Scenario
2009
We study the optical and X-ray emission from protostellar jets, focusing, in particular, on the case of HH 154. This project consists of two different and complementary approaches: the development of hydrodynamical models of the jet/ambient interaction, and the analysis of multi-wavelength observations. Comparing the results derived from the simulations with the observations we can infer the physical mechanisms leading to the complex morphology of the X-rays source observed at the base of HH 154.
Cluster growth with long-range interactions
1996
Abstract Growth models in which the morphology depends on interactions of the type V(r) = C r n are presented. The growth algorithms are generalizations of DLA. The particles diffuse on a triangular lattice and eventually either stick to the cluster or are lost. Several processes are simulated in this way: in one case only pure sticking is taken into account, in another case evaporation and rearrangement are also allowed to occur. In the former case (with attractive interactions) the clusters exhibit a highly symmetric shape (a sixfold star) whose detailed structure depends on n , C kT , and time. In the latter case (studied with repulsive dipolar interactions) the tendency to ramification …
SDSS DR7 superclusters. Morphology
2011
We study the morphology of a set of superclusters drawn from the SDSS DR7. We calculate the luminosity density field to determine superclusters from a flux- limited sample of galaxies from SDSS DR7, and select superclusters with 300 and more galaxies for our study. The morphology of superclusters is described with the fourth Minkowski functional V3, the morphological signature (the curve in the shapefinder's K1-K2 plane) and the shape parameter (the ratio of the shapefinders K1/K2). We investigate the supercluster sample using multidimensional normal mixture modelling, and use Abell clusters to identify our superclusters with known superclusters and to study the large-scale distribution of …
On the metal abundances inside mixed-morphology supernova remnants: the case of IC 443 and G166.0+4.3
2009
Recent developments on the study of mixed morphology supernova remnants (MMSNRs) have revealed the presence of metal rich X-ray emitting plasma inside a fraction of these remnant, a feature not properly addressed by traditional models for these objects. Radial profiles of thermodynamical and chemical parameters are needed for a fruitful comparison of data and model of MMSNRs, but these are available only in a few cases. We analyze XMM-Newton data of two MMSNRs, namely IC443 and G166.0+4.3, previously known to have solar metal abundances, and we perform spatially resolved spectral analysis of the X-ray emission. We detected enhanced abundances of Ne, Mg and Si in the hard X-ray bright peak i…
Environmental impact of magmatic fluorine emission in the Mt. Etna area
2007
-UniversitA degli Studi di Palermo, Italy -Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo - Unione Europea, Fondo Sociale Europeo
Electron Holography for Electric and Magnetic Field Measurements and Its Application for Nanophysics
2011
Abstract Texture constitutes one of the fundamental properties of objects besides color and shape. In several image analysis applications, it is often the only exploitable quality of objects. As such, it has been studied, described, segmented, synthesized, or in short, analyzed extensively. Among the plethora of texture description methods, mathematical morphology deserves special attention as it excels at the exploitation of spatial relationships among pixels, rendering it inherently suitable for texture description. In this chapter, we focus on morphological texture description methods for grey-scale and color images in an effort to spread the advantages of this framework in the context o…
Integrated geomorphological mapping in the north-western sector of Agrigento (Italy)
2012
The geomorphological map is an essential tool to perform a proper urban planning in mountainous or hilly areas. In this paper a multidisciplinary approach to derive a 1:2000 geomorphological map is described. The proposed methodology consists of the integration between aerial photographs, acquired in 2003, and four datasets of Persistent Scatterer Interferometry (PSI) measures to update a pre-existing landslide inventory. The integrated data were used to achieve a validated geomorphological map by means of a geomorphological survey. The study area is located in southern Italy (Agrigento, Sicily). The city of Agrigento, included in the World Heritage List of UNESCO in 1997, is located on the…