Sapienza University of Rome

About: Sapienza University of Rome is a education organization based out in Rome, Lazio, Italy. It is known for research contribution in the topics: Population & Medicine. The organization has 62002 authors who have published 155468 publications receiving 4397244 citations. The organization is also known as: La Sapienza & Università La Sapienza di Roma.

Planck early results - VIII. The all-sky early Sunyaev-Zeldovich cluster sample

Abstract: We present the first all-sky sample of galaxy clusters detected blindly by the Planck satellite through the Sunyaev-Zeldovich (SZ) effect from its six highest frequencies. This early SZ (ESZ) sample is comprised of 189 candidates, which have a high signal-to-noise ratio ranging from 6 to 29. Its high reliability (purity above 95%) is further ensured by an extensive validation process based on Planck internal quality assessments and by external cross-identification and follow-up observations. Planck provides the first measured SZ signal for about 80% of the 169 previouslyknown ESZ clusters. Planck furthermore releases 30 new cluster candidates, amongst which 20 meet the ESZ signal-to-noise selection criterion. At the submission date, twelve of the 20 ESZ candidates were confirmed as new clusters, with eleven confirmed using XMM-Newton snapshot observations, most of them with disturbed morphologies and low luminosities. The ESZ clusters are mostly at moderate redshifts (86% with z below 0.3) and span more than a decade in mass, up to the rarest and most massive clusters with masses above 1 × 10 15 M� .

Analysis of Plasmodium falciparum diversity in natural infections by deep sequencing

Abstract: methods for the large-scale analysis of genetic variation in Plasmodium falciparum by deep sequencing of parasite DNA obtained from the blood of patients with malaria, either directly or after short-term culture Analysis of 86,158 exonic single nucleotide polymorphisms that passed genotyping quality control in 227 samples from Africa, Asia and Oceania provides genomewide estimates of allele frequency distribution, population structure and linkage disequilibrium By comparing the genetic diversity of individual infections with that of the local parasite population, we derive a metric of within-host diversity that is related to the level of inbreeding in the population An open-access web application has been established for the exploration of regional differences in allele frequency and of highly differentiated loci in the P falciparum genome The genetic diversity and evolutionary plasticity of P falciparum are major obstacles for malaria elimination New forms of resistance against antimalarial drugs are continually emerging 1,2 , and new forms of antigenic variation are a critical point of vulnerability for future malaria vaccines Effective tools are needed to detect evolutionary changes in the parasite population and to monitor the spread of genetic variants that affect malaria control Here we describe the use of deep sequencing to analyse P falciparum diversity, using blood samples from patients with malaria The P falciparum genome has several unusual features that greatly complicate sequence analysis, such as extreme AT bias, large tracts of nonunique sequence and several large families of intensely polymorphic genes 3 Our aim was therefore not to determine the entire genome sequence of individual field samples—which would be prohibitively expensive with current technologies—but to define an initial set of single nucleotide polymorphisms (SNPs) distributed across the P falciparum genome, whose genotype can be ascertained with confidence in parasitized blood samples by deep sequencing An additional complication in the analysis of P falciparum genome variation is that the billions of haploid parasites that infect a single individual can be a complex mixture of genetic types Previous studies 4–8 have largely focused on laboratory-adapted parasite clones, but the within-host diversity of natural infections is of fundamental biological interest Parasites in the blood replicate asexually, but when they are taken up in the blood meal of an Anopheles mosquito they undergo sexual mating If the parasites in the blood are of diverse genetic types, this process of sexual mating can generate novel recombinant forms Deep sequencing provides new ways of investigating within-host diversity and the role of sexual recombination in parasite evolution

Learning Domain Ontologies from Document Warehouses and Dedicated Web Sites

Abstract: We present a method and a tool, OntoLearn, aimed at the extraction of domain ontologies from Web sites, and more generally from documents shared among the members of virtual organizations. OntoLearn first extracts a domain terminology from available documents. Then, complex domain terms are semantically interpreted and arranged in a hierarchical fashion. Finally, a general-purpose ontology, WordNet, is trimmed and enriched with the detected domain concepts. The major novel aspect of this approach is semantic interpretation, that is, the association of a complex concept with a complex term . This involves finding the appropriate WordNet concept for each word of a terminological string and the appropriate conceptual relations that hold among the concept components. Semantic interpretation is based on a new word sense disambiguation algorithm, called structural semantic interconnections.