Individuazione delle tipologie di pendolari nel Friuli Venezia Giulia

Nel presente lavoro si utilizza la matrice del pendolarismo, costruita a partire dai dati censuari, per l’individuazione di tipologie di pendolari a seconda che il motivo dello spostamento sia lo studio o il lavoro distinguendo tra comuni sotto e sopra i 20000 abitanti. La matrice del pendolarismo infatti fornisce informazioni relative ai movimenti giornalieri da e per i comuni di residenza e di lavoro (o studio), considerando i movimenti che prevedono il rientro in giornata all’abitazione di residenza. Il dettaglio territoriale considerato nella matrice (disponibile sul sito dell’Istat) è il comune, all’interno del quale vengono stratificati i pendolari sulla base di alcune variabili rilevanti, che non sono però le sole che possono influenzare e spiegare il pendolarismo. Al fine dell’identificazione delle tipologie di pendolari si utilizza la cluster analysis. La cluster analysis, ha l’obiettivo di riconoscere dei gruppi che appaiono con “naturalezza” nelle osservazioni e che si caratterizzano per un’elevata omogeneità all’interno dei gruppi stessi e per un’elevata eterogeneità tra di essi. In pratica, partendo dai dati, si vogliono ottenere dei cluster distinti di elementi raggruppati in base alla loro distanza o similarità misurata su alcune variabili rilevanti. Tra i diversi metodi si è scelta la two step cluster analysis in quanto permette di analizzare una grossa mole di dati e di considerare sia variabili quantitative che qualitative.This paper uses the matrix of commuting, constructed from Census data, for the identification of types of commuters travelling for study or work, distinguishing between municipalities below and over 20,000 inhabitants. The commuting matrix has information about daily movements to and from town of residence and work (or study). The considered territorial level is the municipality, whitin which the commuters are stratified on the basis of some rilevant variables. In order to identify the types of commuters the cluster analysis is used. Cluster analysis, aims at recognizing the groups that appear with “naturalness” in the observations and which are characterized by high homogeneity within the groups and high heterogeneity between them. In practice, starting from the data, we want to obtain clusters of elements grouped according to their similarity or distance measured on some relevant variables. Among the different methods, we choose the two-step cluster analysis as it allows to analyze a large amount of data and to consider both quantitative and qualitative variables

The distribution of H13CN in the circumstellar envelope around IRC+10216

H13CN J=8-7 sub-millimetre line emission produced in the circumstellar envelope around the extreme carbon star IRC+10216 has been imaged at sub-arcsecond angular resolution using the SMA. Supplemented by a detailed excitation analysis the average fractional abundance of H13CN in the inner wind (< 5E15 cm) is estimated to be about 4E-7, translating into a total HCN fractional abundance of 2E-5 using the isotopic ratio 12C/13C=50. Multi-transitional single-dish observations further requires the H13CN fractional abundance to remain more or less constant in the envelope out to a radius of about 4E16 cm, where the HCN molecules are effectively destroyed, most probably, by photodissociation. The large amount of HCN present in the inner wind provides effective line cooling that can dominate over that generated from CO line emission. It is also shown that great care needs to be taken in the radiative transfer modelling where non-local, and non-LTE, effects are important and where the radiation field from thermal dust grains plays a major role in exciting the HCN molecules. The amount of HCN present in the circumstellar envelope around IRC+10216 is consistent with predicted photospheric values based on equilibrium chemical models and indicates that any non-equilibrium chemistry occurring in the extended pulsating atmosphere has no drastic net effect on the fractional abundance of HCN molecules that enters the outer envelope. It further suggests that few HCN molecules are incorporated into dust grains.Comment: Accepted for publication in ApJ. 20 pages, 7 figure

Análise evolutiva das Metionina Aminopeptidases : uma abordagem bioinformática

A Excisão de Metionina N-terminal (EMN) é um processo que ocorre em cerca de 30% a 60% de todas proteínas expressadas por um genoma, a depender do organismo e seu compartimento celular. Este é um processo conservado em todos domínios da vida e essencial para manutenção da funcionalidade e do crescimento celular em qualquer organismo investigado. Através do seu controle global da meia vida de proteínas, a EMN já demonstrou regular a homeostase redox global de glutationa, ao menos em plantas, leveduras e arqueas. A enzima responsável pela EMN se chama Metionina Aminopeptidase (MetAP). Assim como a EMN, as MetAPs são conservadas em bactérias, arqueas e eucariotos. Já se comprovou um papel fundamental de MetAPs humanas nos processos de angiogênese e de linfogênese. As MetAPs são alvos terapêuticos em uma vasta gama de estudos que vão desde terapias anti câncer a tratamentos de zoonoses. Estruturalmente, todas variantes de MetAP apresentam um eixo de simetria pseudo two fold com um sítio catalítico e um sítio de ligação a íon metálico na interface entre os domínios. Os tipos e subtipos de MetAP caracterizam-se pela presença ou ausência de inserções adicionais nas regiões C-terminal e N-terminal, respectivamente. A distribuição dos tipos de MetAPs ao longo da biodiversidade se dá de maneira que, em seus genomas, bactérias apresentam apenas genes homólogos a MetAP do tipo 1 (MetAP1), arqueas apresentam apenas genes homólogos a MetAP do tipo 2 (MetAP2) e eucariotos apresentam genes homólogos a ambos tipos. Adicionalmente, eucariotos apresentam variantes de MetAP1 localizadas no interior de suas mitocôndrias e/ou plastídeos. Apesar de se atribuir a presença de homólogos a ambos tipos de MetAP em eucariotos a eventos endossimbióticos, pouco se sabe sobre as origens evolutivas de cada uma das variantes de MetAP. Neste estudo, analisamos a distribuição dos tipos e subtipos de MetAP ao longo da biodiversidade, investigando possíveis candidatos a variantes ainda não identificadas, assim como realizamos a construção de um modelo filogenético para a evolução das MetAPs. Resultados preliminares indicam a ocorrência de membros de MetAP2 em uma família bacteriana, o que é indicativo da necessidade de uma melhor descrição da distribuição dos tipos de MetAP ao longo da árvore da vida.N-terminal Methionine Excision (NME) is a process that occurs in about 30% to 60% of all expressed proteins in a genome, depending on the organism and cellular compartment. It is conserved through all life domains and it is essential for normal growth and function in any organism investigated. By means of its capability of control over protein half-life, NME has demonstrated to regulate global glutathione redox homeostasis, at least in plants, yeast and Archaea. The enzyme responsible for NME carriage is Methionine Aminopeptidase (MetAP). Like NME, MetAPs are conserved in Bacteria, Archaea and Eukaryotes. It has proven to play a primordial role in human angiogenesis and lymphangiogenesis processes. MetAPs are pharmaceutical targets in a wide range of studies ranging from anti-cancer therapies to zoonose treatments. Structurally, every MetAP variant presents a pseudo twofold symmetry axis of symmetry with the catalytic site and metal ion binding located at the interfaces between the domains. The types and subtypes of MetAP are characterized by the presence or absence of additional insertions in their C-termini and N-termini regions, respectively. The distribution of types of MetAPs along biodiversity is given in a way that, in their genome, Bacteria presents only genes homologous to type 1 MetAP (MetAP1), Archaea presents only genes homologous to type 2 MetAP (MetAP2) and Eukaryotes presents genes homologous to both types. Additionally, Eukaryotes present MetAP1 variants that are located inside their mitochondria and/or plastids. Despite the presence of both homologous types of MetAP in eukaryotes is attributed to endosymbiotic events, little is known about the evolutionary origins of each MetAP variant. In the present study, we analyze the distribution of MetAP types and subtypes across biodiversity, investigating possible candidates for as-yet-unidentified variants, as well as construct a phylogenetic model of MetAPs evolution. Preliminary results indicate the occurrence of MetAP2 members in a bacterial family, which is indicative of the necessity of better description of the MetAP types distribution along the tree of life

Stochastic Blockmodeling for the Analysis of Big Data

The aim of this paper is to consider the stochastic blockmodel to obtain clusters of units as regards patterns of similar relations; moreover we want to analyze the relations between clusters. Blockmodeling is a technique usually applied in social network analysis focusing on the relations between \u201cactors\u201d i.e. units. In our time people and devices constantly generate data. The network is generating location and other data that keeps services running and ready to use in every moment. This rapid development in the availability and access to data has induced the need for better analysis techniques to understand the various phenomena. Blockmodeling techniques and Clustering algorithms, can be used for this aim. In this paper application regards the Web

PROSAC: A Submillimeter Array Survey of Low-Mass Protostars. I. Overview of Program: Envelopes, Disks, Outflows and Hot Cores

This paper presents a large spectral line and continuum survey of 8 deeply embedded, low-mass protostellar cores using the Submillimeter Array. Each source was observed in high excitation lines of some of the most common molecular species, CO, HCO+, CS, SO, H2CO, CH3OH and SiO. Line emission from 11 species originating from warm and dense gas have been imaged at high angular resolution (1-3"; typically 200-600 AU) together with continuum emission at 230 GHz (1.3 mm) and 345 GHz (0.8 mm). Compact continuum emission is observed for all sources which likely originates in marginally optically thick circumstellar disks, with typical lower limits to their masses of 0.1 M_sun (1-10% of the masses of their envelopes) and having a dust opacity law with beta approximately 1. Prominent outflows are present in CO 2-1 observations in all sources: the most diffuse outflows are found in the sources with the lowest ratios of disk-to-envelope mass, and it is suggested that these sources are in a phase where accretion of matter from the envelope has almost finished and the remainder of the envelope material is being dispersed by the outflows. Other characteristic dynamical signatures are found with inverse P Cygni profiles indicative of infalling motions seen in the 13CO 2-1 lines toward NGC1333-IRAS4A and -IRAS4B. Outflow-induced shocks are present on all scales in the protostellar environments and are most clearly traced by the emission of CH3OH in NGC1333-IRAS4A and -IRAS4B. These observations suggest that the emission of CH3OH and H2CO from these proposed "hot corinos" are related to the shocks caused by the protostellar outflows. Only one source, NGC1333-IRAS2A, has evidence for hot, compact CH3OH emission coincident with the embedded protostar.Comment: Accepted for publication in ApJ (52 pages; 9 figures). Abstract abridge

First detection of triply-deuterated methanol

We report the first detection of triply-deuterated methanol, with 12 observed transitions, towards the low-mass protostar IRAS 16293-2422, as well as multifrequency observations of 13CH3OH, used to derive the column density of the main isotopomer CH3OH. The derived fractionation ratio [CD3OH]/[CH3OH] averaged on a 10'' beam is 1.4%. Together with previous CH2DOH and CHD2OH observations, the present CD3OH observations are consistent with a formation of methanol on grain surfaces, if the atomic D/H ratio is 0.1 to 0.3 in the accreting gas. Such a high atomic ratio can be reached in the frame of gas-phase chemical models including all deuterated isotopomers of H3+.Comment: Accepted by A&

CO abundances in a protostellar cloud: freeze-out and desorption in the envelope and outflow of L483

CO isotopes are able to probe the different components in protostellar clouds. These components, core, envelope and outflow have distinct physical conditions and sometimes more than one component contributes to the observed line profile. In this study we determine how CO isotope abundances are altered by the physical conditions in the different components. We use a 3D molecular line transport code to simulate the emission of four CO isotopomers, 12CO J=2-1, 13CO J=2-1, C18O J=2-1 and C17O J=2-1 from the Class 0/1 object L483, which contains a cold quiescent core, an infalling envelope and a clear outflow. Our models replicate JCMT (James Clerk Maxwell Telescope) line observations with the inclusion of freeze-out, a density profile and infall. Our model profiles of 12CO and 13CO have a large linewidth due to a high velocity jet. These profiles replicate the process of more abundant material being susceptible to a jet. C18O and C17O do not display such a large linewidth as they trace denser quiescent material deep in the cloud.Comment: 9 figures, 13 pages, 2 table

Modelling CO emission from Mira's wind

We have modelled the circumstellar envelope of {\it o} Ceti (Mira) using new observational constraints. These are obtained from photospheric light scattered in near-IR vibrational-rotational lines of circumstellar CO molecules at 4.6 micron: absolute fluxes, the radial dependence of the scattered intensity, and two line ratios. Further observational constraints are provided by ISO observations of far-IR emission lines from highly excited rotational states of the ground vibrational state of CO, and radio observations of lines from rotational levels of low excitation of CO. A code based on the Monte-Carlo technique is used to model the circumstellar line emission. We find that it is possible to model the radio and ISO fluxes, as well as the highly asymmetric radio-line profiles, reasonably well with a spherically symmetric and smooth stellar wind model. However, it is not possible to reproduce the observed NIR line fluxes consistently with a `standard model' of the stellar wind. This is probably due to incorrectly specified conditions of the inner regions of the wind model, since the stellar flux needs to be larger than what is obtained from the standard model at the point of scattering, i.e., the intermediate regions at approximately 100-400 stellar radii (2"-7") away from the star. Thus, the optical depth in the vibrational-rotational lines from the star to the point of scattering has to be decreased. This can be accomplished in several ways. For instance, the gas close to the star (within approximately 2") could be in such a form that light is able to pass through, either due to the medium being clumpy or by the matter being in radial structures (which, further out, developes into more smooth or shell-like structures).Comment: 18 pages, 3 figures, accepted for publication in Ap

Clustering Algorithms for Spatial Big Data

In our time people and devices constantly generate data. User activity generates data about needs and preferences as well as the quality of their experiences in different ways: i. e. streaming a video, looking at the news, searching for a restaurant or a an hotel, playing a game with others, making purchases, driving a car. Even when people put their devices in their pockets, the network is generating location and other data that keeps services running and ready to use. This rapid developments in the availability and access to data and in particular spatially referenced data in a different areas, has induced the need for better analysis techniques to understand the various phenomena. Spatial clustering algorithms, which groups similar spatial objects into classes, can be used for the identification of areas sharing common characteristics. The aim of this paper is to analyze the performance of three different clustering algorithms i.e. the Density-Based Spatial Clustering of Applications with Noise algorithm (DBSCAN), the Fast Search by Density Peak (FSDP) algorithm and the classic K-means algorithm (K-Means) as regards the analysis of spatial big data. We propose a modification of the FSDP algorithm in order to improve its efficiency in large databases. The applications concern both synthetic data sets and satellite images