Quantifying ethnic segregation in cities through random walks

Socioeconomic segregation has an important role in the emergence of large-scale inequalities in urban areas. Most of the available measures of spatial segregation depend on the scale and size of the system under study, or neglect large-scale spatial correlations, or rely on ad-hoc parameters, making it hard to compare different systems on equal grounds. We propose here a family of non-parametric measures for spatial distributions, based on the statistics of the trajectories of random walks on graphs associated to a spatial system. These quantities provide a consistent estimation of segregation in synthetic spatial patterns, and we use them to analyse the ethnic segregation of metropolitan areas in the US and the UK. We show that the spatial diversity of ethnic distributions, as measured through diffusion on graphs, allow us to compare the ethnic segregation of urban areas having different size, shape, or peculiar microscopic characteristics, and exhibits a strong association with socio-economic deprivation

AMOA, Associazione Medici Oculisti per l'Africa, un esempio di solidariet\ue0 istituzionalizzata. La missione Zimbabwe.

AMOA (Associazione Medici Oculisti per l\u2019Africa), \ue8 un\u2019associazione di volontariato legalmente costituita, con sede a Bologna, aconfessionale che non persegue fini di lucro. L\u2019associazione, improntata al volontariato, svolge metodicamente e con continuit\ue0 attivit\ue0 di cooperazione allo sviluppo in favore delle popolazioni del Terzo Mondo ed in particolare di quelle africane. A tale scopo l\u2019associazione stabilisce con le Autorit\ue0 nazionali dei Paesi in cui opera, con le istituzioni nazionali ed internazionali operanti localmente e le organizzazioni sociali, una fattiva collaborazione nel rispetto delle sovranit\ue0 nazionali e secondo i principi della cooperazione internazionale definiti dalla Carta delle Nazioni Unite. Essa opera per mezzo di medici e paramedici volontari che offrono gratuitamente una parte del loro tempo per servire ai bisogni sanitari delle popolazioni di questi Paesi che si trovano in uno stadio di sottosviluppo sanitario in campo oculistico per mancanza di strutture, risorse economiche e umane. Tra le varie missioni effettuate possiamo menzionare quelle in Senegal, Togo, Etiopia, Madagascar, Rwanda, Cameroun, Zimbabwe. L\u2019analisi del presente lavoro verter\ue0 sull\u2019operato della\u2019associazione in Zimbabwe evidenziando: l\u2019epidemiologia delle patologie oculari della zona di intervento; il trattamento delle cause pi\uf9 frequenti di cecit\ue0: cataratta, glaucoma, malposizione palpebrale da tracoma, i traumi del bulbo oculare; lo screening delle deficienze visive nell\u2019et\ue0 scolare: ipermetropia, miopia, astigmatismo, ambliopia; la correzione della presbiopia che riduce la capacit\ue0 lavorativa dopo i 40 anni; la promozione dell\u2019educazione sanitaria nelle scuole e nei dispensari per la prevenzione primaria e secondaria delle carenze visive; l\u2019addestramento del personale scolastico locale a misurare la capacit\ue0 visiva dei bambini a partire dal periodo prescolare; l\u2019aggiornamento del personale medico alla chirurgia mediante soggiorni sia in loco che in Italia ed infine le ricadute sulle condizioni di salute e benessere dei soggetti coinvolti

Trends Prediction Using Social Diffusion Models

The importance of the ability of predict trends in social media has been growing rapidly in the past few years with the growing dominance of social media in our everyday's life. Whereas many works focus on the detection of anomalies in networks, there exist little theoretical work on the prediction of the likelihood of anomalous network pattern to globally spread and become "trends". In this work we present an analytic model the social diffusion dynamics of spreading network patterns. Our proposed method is based on information diffusion models, and is capable of predicting future trends based on the analysis of past social interactions between the community's members. We present an analytic lower bound for the probability that emerging trends would successful spread through the network. We demonstrate our model using two comprehensive social datasets - the "Friends and Family" experiment that was held in MIT for over a year, where the complete activity of 140 users was analyzed, and a financial dataset containing the complete activities of over 1.5 million members of the "eToro" social trading community.Comment: 6 Pages + Appendi

biogas from municipal solid waste landfills a simplified mathematical model

Abstract Municipal solid waste (MSW) landfills now represent one of the most important issues related to the waste management cycle. Knowledge of biogas production is a key aspect for the proper exploitation of this energy source, even in the post-closure period. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on first-order biodegradation kinetics and also takes into account the temperature variation in time and depth as well as landfill settlement. The model was applied to an operating landfill located in Sicily, in Italy, and the first results obtained are promising. Indeed, the results showed a good fit between measured and simulated data. Based on these promising results, the model can also be considered a useful tool for landfill operators for a reliable estimate of the duration of the post-closure period

Influence of a Corpus Luteum Tissue Extract on Rabbit Ovarian Mesothelial Cells

This study investigates rabbit ovarian mesothelial (OM) cells exposed in vitro to a crude corpus luteum extract (CLE; 60 μg/ml). The growth of OM cells was evaluated by measuring the change in cell number (mean % ± standard error of mean, SEM), the number of cell population doublings (CPD ± SEM), and the cell population doubling time in hours (CPDT ± SEM) after 7.5 days of culture in a serum-poor medium. Quantitative estimates of surface morphology changes were obtained by analyzing the total number (mean no. ± SEM), density (mean no./100 μ.m2 ± SEM), and length-to-diameter ratio (mean L/D ± SEM) of microvilli. OM cells in control medium formed loosely cohesive monolayers, and grew 152.53 ± 11.01% with a CPD of 0.59 ± 0.08 and a CPDT of 117.29 ± 6.43 hours. The exposed surface area of these cells was over 8,000 μ.m2 and was covered in its epinuclear region by long and slender microvilli with a L/D of 6.01 ± 0.29. The total number of microvilli in each control cell was 1977.52 ± 120.49 with a density of 0.58 ± 0.03/100 μ.m2 in the epinuclear region and of 0.05 ± 0.003/150 μ.m2 in the remaining surface area (5,161.62 ± 354.43 μ.m2). In contrast, CLE-rich cells cultures grew 329.57 ± 16.65%, with a CPD of 1.71 ± 0.07 and a CPDT of 53.43 + 2.93 hours. These cells formed confluent monolayers of smaller (2104.86 ± 103.71 μ.m2), tightly juxtaposed epithelioid cells with a microvillar density of 0.70 ± 0.03/100 μ.m2 in over 78% of their surface. These data support the existence of an intra-ovarian factor capable of enhancing growth and differentiation of OM cells

Metallothionein gene family in the sea urchin Paracentrotus lividus: Gene structure, differential expression and phylogenetic analysis

Metallothioneins (MT) are small and cysteine-rich proteins that bind metal ions such as zinc, copper, cadmium, and nickel. In order to shed some light on MT gene structure and evolution, we cloned seven Paracentrotus lividus MT genes, comparing them to Echinodermata and Chordata genes. Moreover, we performed a phylogenetic analysis of 32 MTs from different classes of echinoderms and 13 MTs from the most ancient chordates, highlighting the relationships between them. Since MTs have multiple roles in the cells, we performed RT-qPCR and in situ hybridization experiments to understand better MT functions in sea urchin embryos. Results showed that the expression of MTs is regulated throughout development in a cell type-specific manner and in response to various metals. The MT7 transcript is expressed in all tissues, especially in the stomach and in the intestine of the larva, but it is less metal-responsive. In contrast, MT8 is ectodermic and rises only at relatively high metal doses. MT5 and MT6 expression is highly stimulated by metals in the mesenchyme cells. Our results suggest that the P. lividus MT family originated after the speciation events by gene duplications, evolving developmental and environmental sub-functionalization

Dynamic communicability predicts infectiousness

Using real, time-dependent social interaction data, we look at correlations between some recently proposed dynamic centrality measures and summaries from large-scale epidemic simulations. The evolving network arises from email exchanges. The centrality measures, which are relatively inexpensive to compute, assign rankings to individual nodes based on their ability to broadcast information over the dynamic topology. We compare these with node rankings based on infectiousness that arise when a full stochastic SI simulation is performed over the dynamic network. More precisely, we look at the proportion of the network that a node is able to infect over a fixed time period, and the length of time that it takes for a node to infect half the network.We find that the dynamic centrality measures are an excellent, and inexpensive, proxy for the full simulation-based measures

An intronic cis-regulatory element is crucial for the alpha tubulin Pl-Tuba1a gene activation in the ciliary band and animal pole neurogenic domains during sea urchin development

In sea urchin development, structures derived from neurogenic territory control the swimming and feeding responses of the pluteus as well as the process of metamorphosis. We have previously isolated an alpha tubulin family member of Paracentrotus lividus (Pl-Tuba1a, formerly known as Pl-Talpha2) that is specifically expressed in the ciliary band and animal pole neurogenic domains of the sea urchin embryo. In order to identify cis-regulatory elements controlling its spatio-temporal expression, we conducted gene transfer experiments, transgene deletions and site specific mutagenesis. Thus, a genomic region of about 2.6 Kb of Pl-Tuba1a, containing four Interspecifically Conserved Regions (ICRs), was identified as responsible for proper gene expression. An enhancer role was ascribed to ICR1 and ICR2, while ICR3 exerted a pivotal role in basal expression, restricting Tuba1a expression to the proper territories of the embryo. Additionally, the mutation of the forkhead box consensus sequence binding site in ICR3 prevented Pl-Tuba1a expression

Physically active workers from Primorsko-goranska County, Croatia adhere more to Mediterranean diet

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