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Institution

University of Siena

EducationSiena, Italy
About: University of Siena is a education organization based out in Siena, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 12179 authors who have published 33334 publications receiving 1008287 citations. The organization is also known as: Università degli studi di Siena & Universita degli studi di Siena.


Papers
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Proceedings ArticleDOI
01 Dec 2009
TL;DR: A stochastic model predictive control (MPC) formulation based on scenario generation for linear systems affected by discrete multiplicative disturbances is proposed, aimed at obtaining a less conservative control action with respect to classical robust MPC schemes, still enforcing convergence and feasibility properties for the controlled system.
Abstract: In this paper we propose a stochastic model predictive control (MPC) formulation based on scenario generation for linear systems affected by discrete multiplicative disturbances. By separating the problems of (1) stochastic performance, and (2) stochastic stabilization and robust constraints fulfillment of the closed-loop system, we aim at obtaining a less conservative control action with respect to classical robust MPC schemes, still enforcing convergence and feasibility properties for the controlled system. Stochastic performance is addressed for very general classes of stochastic disturbance processes, although discretized in the probability space, by adopting ideas from multi-stage stochastic optimization. Stochastic stability and recursive feasibility are enforced through linear matrix inequality (LMI) problems, which are solved off-line; stochastic performance is optimized by an on-line MPC problem which is formulated as a convex quadratically constrained quadratic program (QCQP) and solved in a receding horizon fashion. The performance achieved by the proposed approach is shown in simulation and compared to the one obtained by standard robust and deterministic MPC schemes.

187 citations

Journal ArticleDOI
TL;DR: This is the first report to identify, through various genomic approaches, specific genetic adaptations of a Bifidobacterium taxon to a lifestyle as a cariogenic microorganism in the oral cavity.
Abstract: Bifidobacteria, one of the relatively dominant components of the human intestinal microbiota, are considered one of the key groups of beneficial intestinal bacteria (probiotic bacteria). However, in addition to health-promoting taxa, the genus Bifidobacterium also includes Bifidobacterium dentium, an opportunistic cariogenic pathogen. The genetic basis for the ability of B. dentium to survive in the oral cavity and contribute to caries development is not understood. The genome of B. dentium Bd1, a strain isolated from dental caries, was sequenced to completion to uncover a single circular 2,636,368 base pair chromosome with 2,143 predicted open reading frames. Annotation of the genome sequence revealed multiple ways in which B. dentium has adapted to the oral environment through specialized nutrient acquisition, defences against antimicrobials, and gene products that increase fitness and competitiveness within the oral niche. B. dentium Bd1 was shown to metabolize a wide variety of carbohydrates, consistent with genome-based predictions, while colonization and persistence factors implicated in tissue adhesion, acid tolerance, and the metabolism of human saliva-derived compounds were also identified. Global transcriptome analysis demonstrated that many of the genes encoding these predicted traits are highly expressed under relevant physiological conditions. This is the first report to identify, through various genomic approaches, specific genetic adaptations of a Bifidobacterium taxon, Bifidobacterium dentium Bd1, to a lifestyle as a cariogenic microorganism in the oral cavity. In silico analysis and comparative genomic hybridization experiments clearly reveal a high level of genome conservation among various B. dentium strains. The data indicate that the genome of this opportunistic cariogen has evolved through a very limited number of horizontal gene acquisition events, highlighting the narrow boundaries that separate commensals from opportunistic pathogens.

187 citations

Journal ArticleDOI
TL;DR: Caspase-3 activation can be envisaged as a novel mechanism which, by impairing the maintenance of erythrocyte shape and function, might contribute to the shortened life span of RBCs from patients with type 2 diabetes and to hemorheological disorders observed in these patients.
Abstract: An increased oxidative stress and a decreased life span of erythrocytes (RBCs) are reported in patients with diabetes. Aim of this study was to assess in RBCs from patients with type 2 diabetes whether downstream effector mechanisms of apoptosis, such as activation of caspase-3, is operative, and whether an iron-related oxidative imbalance, occurring inside RBCs and in plasma, could be involved in caspase-3 activation. In 26 patients with type 2 diabetes and in 12 healthy subjects, oxidative stress was evaluated by means of different markers; non-protein-bound iron, methemoglobin and glutathione were determined in RBCs, and non-protein-bound iron was also determined in plasma. Erythrocyte caspase-3 activation was evaluated by an immunosorbent enzyme assay. Arterial hypertension, demographic and standard biochemical data were also evaluated. The results show, for the first time, that type 2 diabetic RBCs put into motion caspase-3 activation, which is significantly higher than in control RBCs. Such an effector mechanism of “eryptosis” was positively correlated to blood glucose levels and to the increased plasma NPBI level. Caspase-3 activation was also positively correlated to occurrence of arterial hypertension. The results suggest that an extracellular oxidative milieu can be responsible for erythrocyte caspase-3 activation in patients with type 2 diabetes. In turn, caspase-3 activation can be envisaged as a novel mechanism which, by impairing the maintenance of erythrocyte shape and function, might contribute to the shortened life span of RBCs from patients with type 2 diabetes and to hemorheological disorders observed in these patients.

187 citations

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, Fausto Acernese2, Fausto Acernese3  +702 moreInstitutions (85)
TL;DR: In this article, an updated search for gravitational waves from 116 known millisecond and young pulsars using data from the fifth science run of the LIGO detectors was presented, where ephemerides overlapping the run period were obtained using radio and X-ray observations.
Abstract: We present a search for gravitational waves from 116 known millisecond and young pulsars using data from the fifth science run of the LIGO detectors. For this search ephemerides overlapping the run period were obtained for all pulsars using radio and X-ray observations. We demonstrate an updated search method that allows for small uncertainties in the pulsar phase parameters to be included in the search. We report no signal detection from any of the targets and therefore interpret our results as upper limits on the gravitational wave signal strength. The most interesting limits are those for young pulsars. We present updated limits on gravitational radiation from the Crab pulsar, where the measured limit is now a factor of seven below the spin-down limit. This limits the power radiated via gravitational waves to be less than ~2% of the available spin-down power. For the X-ray pulsar J0537-6910 we reach the spin-down limit under the assumption that any gravitational wave signal from it stays phase locked to the X-ray pulses over timing glitches, and for pulsars J1913+1011 and J1952+3252 we are only a factor of a few above the spin-down limit. Of the recycled millisecond pulsars several of the measured upper limits are only about an order of magnitude above their spin-down limits. For these our best (lowest) upper limit on gravitational wave amplitude is 2.3x10^-26 for J1603-7202 and our best (lowest) limit on the inferred pulsar ellipticity is 7.0x10^-8 for J2124-3358.

187 citations

Journal ArticleDOI
TL;DR: The exposure to environmental pro‐oxidant agents leads to the formation of reactive oxygen species (ROS) and the generation of bioactive molecules that can damage skin cells.
Abstract: Living organisms are continuously exposed to environmental pollutants Because of its critical location, the skin is a major interface between the body and the environment and provides a biological barrier against an array of chemical and physical environmental pollutants The skin can be defined as our first defense against the environment because of its constant exposure to oxidants, including ultraviolet (UV) radiation and other environmental pollutants such as diesel fuel exhaust, cigarette smoke (CS), halogenated hydrocarbons, heavy metals, and ozone (O3) The exposure to environmental pro-oxidant agents leads to the formation of reactive oxygen species (ROS) and the generation of bioactive molecules that can damage skin cells This short review provides an overview of the effects and mechanisms of action of CS, O3, and UV on cutanous tissues

186 citations


Authors

Showing all 12352 results

NameH-indexPapersCitations
Johan Auwerx15865395779
I. V. Gorelov1391916103133
Roberto Tenchini133139094541
Francesco Fabozzi133156193364
M. Davier1321449107642
Roberto Dell'Orso132141292792
Rino Rappuoli13281664660
Teimuraz Lomtadze12989380314
Manas Maity129130987465
Dezso Horvath128128388111
Paolo Azzurri126105881651
Vincenzo Di Marzo12665960240
Igor Katkov12597271845
Ying Lu12370862645
Thomas Schwarz12370154560
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202391
2022221
20211,870
20201,979
20191,639
20181,523