1,100 research outputs found
Private Equity and Leveraged Buyouts in Italy. To Prohibit or Not to Prohibit, That is the Question
No full textThe purpose of the study by S. Zambelli is two-fold.
First, the paper discusses the evolution of the Private Equity (PE) market in Italy, in relation to several changes in regulation (especially with reference to the financial assistance rule for a share-buyback purpose).
Second, the paper empirically analyzes the economic impact of a new PE and LBO reform on financial markets and investor behavior (effective from January 2004).
The empirical analysis underlying the paper is based on a novel and new database, hand-collected by the Author via a survey methodology, which consists of 162 PE transactions carried out during the 1999-2006 period.
The economic impact of the new PE reform includes a comprehensive analysis of the entire private equity cycle, with a special focus on the following issues:
- Impact on the private equity market;
- Impact on the deal structure and forms of finance;
- Impact on the adoption of convertible securities;
- Impact on the governance of the target;
- Impact on the evaluation process of the target firm.
The Italian private equity and buyout market, whose transactions were previously prohibited and only recently legalized, offers a unique example in order to evaluate the impact of the new LBO law on investors' behavior
ELECTRICAL CHARACTERIZATION, PHYSICS, MODELING AND RELIABILITY OF INNOVATIVE NON-VOLATILE MEMORIES
No full textEnclosed in this thesis work it can be found the results of a three years long research
activity performed during the XXIV-th cycle of the Ph.D. school in Engineering Science of
the Università degli Studi di Ferrara. The topic of this work is concerned about the
electrical characterization, physics, modeling and reliability of innovative non-volatile
memories, addressing most of the proposed alternative to the floating-gate based
memories which currently are facing a technology dead end. Throughout the chapters of
this thesis it will be provided a detailed characterization of the envisioned replacements for
the common NOR and NAND Flash technologies into the near future embedded and
MPSoCs (Multi Processing System on Chip) systems. In Chapter 1 it will be introduced the
non-volatile memory technology with direct reference on nowadays Flash mainstream,
providing indications and comments on why the system designers should be forced to
change the approach to new memory concepts. In Chapter 2 it will be presented one of the
most studied post-floating gate memory technology for MPSoCs: the Phase Change
Memory. The results of an extensive electrical characterization performed on these
devices led to important discoveries such as the kinematics of the erase operation and
potential reliability threats in memory operations. A modeling framework has been
developed to support the experimental results and to validate them on projected scaled
technology. In Chapter 3 an embedded memory for automotive environment will be shown:
the SimpleEE p-channel memory. The characterization of this memory proven the
technology robustness providing at the same time new insights on the erratic bits
phenomenon largely studied on NOR and NAND counterparts. Chapter 4 will show the
research studies performed on a memory device based on the Nano-MEMS concept. This
particular memory generation proves to be integrated in very harsh environment such as
military applications, geothermal and space avionics. A detailed study on the physical
principles underlying this memory will be presented. In Chapter 5 a successor of the
standard NAND Flash will be analyzed: the Charge Trapping NAND. This kind of memory
shares the same principles of the traditional floating gate technology except for the storage
medium which now has been substituted by a discrete nature storage (i.e. silicon nitride
traps). The conclusions and the results summary for each memory technology will be
provided in Chapter 6. Finally, on Appendix A it will be shown the results of a recently
started research activity on the high level reliability memory management exploiting the
results of the studies for Phase Change Memories
Introduction to ELIXIR infrastructure in Italy
No full textA brief introduction to the ELIXIR infrastructure in Italy.
ELIXIR is a distributed infrastructure for life science data.
ELIXIR is a intergovernmental organisation that brings together "bioinformatic resources" for life sciences from across Europe. Rhese resources include databases, software tools, training materials, best practices, computational resources, and more.
The goal of ELIXIR is to coordinate and integrate these resources so that they form a single infrastructure. In turn, this infrastructure makes it easier for scientists to find and share data, exchange expertise and agree on best practice.
ELIXIR connects national bioinformatic centres and EMBL-EBI into a sustainable European infrastructure for biological research data.
ELIXIR underpins life science research across academia and industry
Genome wide features, distribution and correlations of NF-Y binding sites
No full textNF-Y is a trimeric transcription factor that binds on DNA the CCAAT-box motif. In this article we reviewed and complemented with additional bioinformatic analysis existing data on genome-wide NF-Y binding characterization in human, reaching the following main conclusions: (1) about half of NF-Y binding sites are located at promoters, about 60-80 base pairs from transcription start sites; NF-Y binding to distal genomic regions takes place at inactive chromatin loci and/or DNA repetitive elements more often than active enhancers; (2) on almost half of its binding sites, regardless of their genomic localization (promoters or distal regions), NF-Y finds on DNA more than one CCAAT-box, and most of those multiple CCAAT binding loci present precise spacing and organization of the elements composing them; (3) there exists a well defined class of transcription factors that show genome-wide co-localization with NF-Y. Some of them lack their canonical binding site in binding regions overlapping with NF-Y, hence hinting at NF-Y mediated recruitment, while others show a precise positioning on DNA of their binding sites with respect to the CCAAT box bound by NF-Y. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani
CSCAN: FINDING COMMON REGULATORS IN A SET OF GENES USING GENOME-WIDE CHIP-SEQ DATA
No full textChIP-Seq has rapidly become the method of choice for the genome-wide
identification of protein-DNA interactions, especially for those proteins involved in
the regulation of gene transcription like transcription factors (TFs) and histones with
their post-translational modifications.
As a consequence, we have now at our disposal genome-wide maps of the binding
of dozens of different TFs or the chromosomal localization of histone modifications
in several different cell lines, like the ones produced in the framework of the
ENCODE project. But, on the other hand, accessing, retrieving and using those
data for further analyses is far from being straightforward. Usually, what is made
available to researchers from a ChIP-Seq experiment is a long list of genomic
coordinates of those regions found to be enriched for the binding of the protein
studied. Genomic browsers like the UCSC Genome Browser permit to retrieve
the data and obtain further pieces of information, for example by crossing the
regions of the protein studied with other data like gene annotations or other ChIPSeq –derived region lists and finding all the putative gene targets of a given TF, but
more involved analyses like computing significant correlations or anti-correlations
among different TFs and/or histone modifications and/or gene expression data are
far from being straightforward.
With these considerations in mind, we retrieved data for about 500 ChIP-Seq
experiments of TFs, about 250 of histone modifications and about 100 of other
molecules like PolII or CTCF in several different cell lines. We then developed a
web-based application called Cscan, permitting to study their correlations with
gene expression data or their respective correlations.
Cscan accepts as input a list of gene identifiers, and outputs, for each of the
experiments available the enrichment of the TF or histone in the promoter region of
the input genes. Enrichment is computed with an exact Fisher test taking into
account: a) the overall number of genes annotated in the genome b) the overall
number of genes of the genome whose promoter contains a region enriched in the experiment c) the number of input genes d) the number of input genes whose
promoter is enriched in the experiment.
There are several different possible applications for a tool of this kind, like for
example:
1. Given a set of co-expressed genes, finding their common regulators, by
looking for TFs with over-represented binding regions in their promoters;
2. Given a ChIP-Seq experiment for a TF and its target genes, find which
other TFs target the same set of genes, and to which extent; that is, discover
correlations or anti-correlations between the TFs or between the TF and histone
modifications;
3. Given a ChIP-Seq experiment for a TF (or a histone modification) in a
given cell line, and the list of genes transcribed in the same cell line (often available
by genome-wide maps of PolII binding) , discover whether the TF can be
hypothesized to be a transcriptional activator or repressor.
Cscan can be accessed through a user-friendly Web interface. A beta version is
available at http://www.beaconlab.it/cscan. At the moment data available are from
human experiments but we plan to add other species in the next future
Formazione degli insegnanti e ricerca didattica universitaria
No full textL’obiettivo di questo articolo e’ quello delineare una struttura universitaria che funga da punto di riferimento per la formazione degli insegnanti a tutti i livelli di istruzione e per l’organizzazione della ricerca didattica ad essa connessa, cercando, al contempo, di stimolare una riflessione su un tema che nel nostro paese e’ stato finora trascurato, quello della formazione didattica dei docenti universitari e del complessivo miglioramento della didattica. A tal fine, viene considerata inizialmente la questione della formazione degli insegnati alla luce delle attuali politiche europee guidate dalla strategia di Lisbona, distinguendo tra scuola e universita' ed esaminando alcuni tra i principali documenti elaborati da organismi europei che forniscono condivisi orientamenti su tale questione. Successivamente, poiche’ per l’istruzione superiore la produzione di documenti e’ più limitata, sono prese in considerazione alcune strutture accademiche largamente diffuse, Centre for Teaching and Learning e Subject Centre, preposte tanto alla formazione degli insegnanti quanto all’organizzazione della ricerca didattica, che esemplificano possibili implementazioni dei recenti orientamenti di politica educativa europea. Entrambe le linee di analisi forniscono molteplici suggerimenti per mettere a punto e realizzare un Centro di ateneo per l’insegnamento e l’apprendimento o un Centro per la didattica disciplinare, che, affrontando anche le problematiche ad essi connesse, si occupi della formazione dei nuovi docenti, del sostegno alla didattica e della ricerca didattica
Prediction of over represented transcription factor binding sites in co-regulated genes using whole genome matching statistics
No full textimportant and challenging problems in molecular biology and bioinformatics. Here we present an algorithm that, given a set of promoters from co-regulated genes, identifies over-represented binding sites by using profiles (position specific frequency matrices) defining the sequence binding specificity of known TFs as well as matching statistics on a whole-genome level, bypassing the need of defining matching thresholds and/or the use of homologous sequences. Preliminary tests performed on experimentally validated sequence sets are very promising; moreover, the same algorithm is suitable also for the use with any model of the binding specificity of TFs
A Faster Algorithm for Motif Finding in Sequences from ChIP-Seq Data
No full textMotif finding in nucleotide sequences for the discovery of over-represented transcription factor binding sites is a very challenging problem, both from the computational and the experimental points of view. Transcription factors in fact recognize very weakly conserved sequence elements, that in typical applications are very hard to discriminate against random sequence similarities. Recent advances in technology like ChIP-Seq can generate better datasets to be investigated, in which the degree of conservation of binding sites is higher: on the other hand, the size itself of the datasets has posed new challenges for the design of efficient algorithms able to produce results in reasonable time. In this work we present an updated version of our algorithm Weeder, in which time and space requirements are significantly reduced and, moreover, also the accuracy of the results is notably improved
WeederH: an algorithm for finding conserved regulatory motifs and regions in homologous sequences
No full textAbstract Background This work addresses the problem of detecting conserved transcription factor binding sites and in general regulatory regions through the analysis of sequences from homologous genes, an approach that is becoming more and more widely used given the ever increasing amount of genomic data available. Results We present an algorithm that identifies conserved transcription factor binding sites in a given sequence by comparing it to one or more homologs, adapting a framework we previously introduced for the discovery of sites in sequences from co-regulated genes. Differently from the most commonly used methods, the approach we present does not need or compute an alignment of the sequences investigated, nor resorts to descriptors of the binding specificity of known transcription factors. The main novel idea we introduce is a relative measure of conservation, assuming that true functional elements should present a higher level of conservation with respect to the rest of the sequence surrounding them. We present tests where we applied the algorithm to the identification of conserved annotated sites in homologous promoters, as well as in distal regions like enhancers. Conclusion Results of the tests show how the algorithm can provide fast and reliable predictions of conserved transcription factor binding sites regulating the transcription of a gene, with better performances than other available methods for the same task. We also show examples on how the algorithm can be successfully employed when promoter annotations of the genes investigated are missing, or when regulatory sites and regions are located far away from the genes.</p
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