Star Operations on Numerical Semigroups

It is proved that the number of numerical semigroups with a fixed number n of star operations is finite if n\ua0>\ua01. The result is then extended to the class of analytically irreducible residually rational one-dimensional Noetherian rings with finite residue field and integral closure equal to a fixed discrete valuation domain

Decomposition and classification of length functions

We study decompositions of length functions on integral domains as sums of length functions constructed from overrings. We find a standard representation when the integral domain admits a Jaffard family, when it is Noetherian and when it is a Pr\ufcfer domains such that every ideal has only finitely many minimal primes. We also show that there is a natural bijective correspondence between singular length functions and localizing systems

Embedding the set of nondivisorial ideals of a numerical semigroup into Nn

The set g(0)(S) of the classes of nondivisorial ideals of a numerical semigroup S can be endowed with a natural partial order induced by the set of star operations on S. We study embeddings of g(0)(S) into N-n, specializing on three families of numerical semigroups with radically different behavior

The Golomb topology on a Dedekind domain and the group of units of its quotients

We study the Golomb spaces of Dedekind domains with torsion class group. In particular, we show that a homeomorphism between two such spaces sends prime ideals into prime ideals and preserves the P-adic topology on R 16P. Under certain hypothesis, we show that we can associate to a prime ideal P of R a partially ordered set, constructed from some subgroups of the group of units of R/Pn, which is invariant under homeomorphisms, and use this result to show that the unique self-homeomorphisms of the Golomb space of Z are the identity and the multiplication by 121. We also show that the Golomb space of any Dedekind domain contained in the algebraic closure of Q and different from Z is not homeomorphic to the Golomb space of Z

The VST telescope control software in the ESO VLT environment

The VST (VLT Survey Telescope) is a 2.6 m Alt-Az telescope to be installed at Mount Paranal in Chile, in the European Southern Observatory (ESO) site. The VST is a wide-field imaging facility planned to supply databases for the ESO Very Large Telescope (VLT) science and carry out stand-alone observations in the UV to I spectral range. This paper will focus mainly on control software aspects, describing the VST software architecture in the context of the whole ESO VLT control concept. The general architecture and the main components of the control software will be described.Comment: 3 pages, 2 figures, ICALEPCS 2001 Conference, PSN#THAP05

Medium Alt-Az Telescope Control System Standardization. A case Study: The TT1 Control System

The TT1 (Toppo Telescope #1) is a 1.54 m Alt-Az telescope designed and built by the Technology Working Group (TWG) of the Astronomical Observatory of Capodimonte (OAC), Naples Italy. The standardization process is of course one of the fundamental requirements for telescope control system design and development, well considered in the TT1 design. In this paper the approach used to identify a control system applicable to medium-size Alt-Az telescope is presented

Impact of polymorphic transposable elements on transcription in lymphoblastoid cell lines from public data

Background: Transposable elements (TEs) are DNA sequences able to mobilize themselves and to increase their copy-number in the host genome. In the past, they have been considered mainly selfish DNA without evident functions. Nevertheless, currently they are believed to have been extensively involved in the evolution of primate genomes, especially from a regulatory perspective. Due to their recent activity they are also one of the primary sources of structural variants (SVs) in the human genome. By taking advantage of sequencing technologies and bioinformatics tools, recent surveys uncovered specific TE structural variants (TEVs) that gave rise to polymorphisms in human populations. When combined with RNA-seq data this information provides the opportunity to study the potential impact of TEs on gene expression in human. Results: In this work, we assessed the effects of the presence of specific TEs in cis on the expression of flanking genes by producing associations between polymorphic TEs and flanking gene expression levels in human lymphoblastoid cell lines. By using public data from the 1000 Genome Project and the Geuvadis consortium, we exploited an expression quantitative trait loci (eQTL) approach integrated with additional bioinformatics data mining analyses. We uncovered human loci enriched for common, less common and rare TEVs and identified 323 significant TEV-cis-eQTL associations. SINE-R/VNTR/Alus (SVAs) resulted the TE class with the strongest effects on gene expression. We also unveiled differential functional enrichments on genes associated to TEVs, genes associated to TEV-cis-eQTLs and genes associated to the genomic regions mostly enriched in TEV-cis-eQTLs highlighting, at multiple levels, the impact of TEVs on the host genome. Finally, we also identified polymorphic TEs putatively embedded in transcriptional units, proposing a novel mechanism in which TEVs may mediate individual-specific traits. Conclusion: We contributed to unveiling the effect of polymorphic TEs on transcription in lymphoblastoid cell lines

Software reverse engineering and development: the VST TCS case

The 2.6 m VST telescope is going to be installed at Cerro Paranal (Chile) as a powerful instrument for optical surveys. It is a joint project between the INAF - Osservatorio Astronomico di Capodimonte (OAC) and ESO. This paper deals with Telescope Control Software (TCS) technical aspects and software engineering design and development strategies