Outer edges of face-on spiral galaxies

We present deep optical imaging of three face-on disk galaxies together with a detailed description of the reduction and calibration methods used, in order to measure the intrinsic shape of their outer stellar edges. Whereas it is now well accepted that disks of spiral galaxies are not infinite exponential beyond galactocentric distances of about 3-5 radial scalelengths, the genuine structure of the truncation region is not yet well known. Our data quantitatively establish a smooth truncation behaviour of the radial surface brightness profiles and is best described by a two-slope model, characterised by an inner and outer exponential scalelength separated at a relatively well defined break radius. This result disagrees with the frequently assumed sharply truncated nature of the radial surface brightness profiles and implies the presence of stars and even star-formation beyond the break radius. In addition, we do not find a strong influence of a nearby companion on the ratio of the break radius to the radial scalelength. Our results denote new observational constraints for the search of the physical explanation for these smooth disk truncations.Comment: LaTeX, 10 pages, 17 figures, accepted to be published in A&A, minor changes to the quality of figure

Why Buckling Stellar Bars Weaken in Disk Galaxies

Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks embedded in live halos, we have analyzed the bar structure throughout this instability and found that the outer third of the bar dissolves completely while the inner part (within the vertical inner Lindblad resonance) becomes less oval. The bar acquires the frequently observed peanut/boxy-shaped isophotes. We also find that the bar buckling is responsible for a mass injection above the plane, which is subsequently trapped by specific 3-D families of periodic orbits of particular shapes explaining the observed isophotes, in line with previous work. Using a 3-D orbit analysis and surfaces of sections, we infer that the outer part of the bar is dissolved by a rapidly widening stochastic region around its corotation radius -- a process related to the bar growth. This leads to a dramatic decrease in the bar size, decrease in the overall bar strength and a mild increase in its pattern speed, but is not expected to lead to a complete bar dissolution. The buckling instability appears primarily responsible for shortening the secular diffusion timescale to a dynamical one when building the boxy isophotes. The sufficiently long timescale of described evolution, ~1 Gyr, can affect the observed bar fraction in local universe and at higher redshifts, both through reduced bar strength and the absence of dust offset lanes in the bar.Comment: 7 pages, 4 figures, ApJ Letters, in pres

DERIVAZIONE DI IDROGRAMMI DI PIENA ATTRAVERSO L\u2019ACCOPPIAMENTO DI MODELLI STOCASTICI BIVARIATI DELLE PRECIPITAZIONI E E MODELLI AFFLUSSI - DEFLUSSI DISTRIBUTI

In questo studio viene presentata una procedura di tipo Monte Carlo per la derivazione delle curve di frequenza delle portate al colmo e dei volumi corrispondenti basata sull\u2019accoppiamento di un modello di generazione delle forzanti pluviometriche tramite copule e un modello di trasformazione afflussideflussi di tipo distribuito. Tale procedura \ue8 stata applicata ad un caso di studio siciliano; i risultati ottenuti hanno mostrato la bont\ue0 del modello a riprodurre le statistiche complesse delle grandezze idrologiche a fronte di un basso numero di parametri modellistici e di un ridotto sforzo computazionale

An agent-based system for maritime search and rescue operations.

Maritime search and rescue operations are critical missions involving personnel, boats, helicopter, aircrafts in a struggle against time often worsened by adversary sea and weather conditions. In such a context, telecommunication and in- formation systems may play a crucial role sometimes concurring to successfully accomplish the mission. In this paper we present an application able to localize the vessel who has launched a rescue request and to plan the most effective path for rescue assets. The application has been realised as a distributed and open multi-agent system deployed on rescue vehicles as well as on a land maritime stations of the Italian Coast Guard. The system is going to be tested in real scenarios by the Coast Guard

Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways

Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins

Regulation of Kir4.1 expression in astrocytes and astrocytic tumors: a role for interleukin-1 beta

<p>Abstract</p> <p>Objective</p> <p>Decreased expression of inwardly rectifying potassium (Kir) channels in astrocytes and glioma cells may contribute to impaired K⁺ buffering and increased propensity for seizures. Here, we evaluated the potential effect of inflammatory molecules, such as interleukin-1β (IL-1β) on Kir4.1 mRNA and protein expression.</p> <p>Methods</p> <p>We investigated Kir4.1 (Kcnj10) and IL-1β mRNA expression in the temporal cortex in a rat model of temporal lobe epilepsy 24 h and 1 week after induction of status epilepticus (SE), using real-time PCR and western blot analysis. The U373 glioblastoma cell line and human fetal astrocytes were used to study the regulation of Kir4.1 expression in response to pro-inflammatory cytokines. Expression of Kir4.1 protein was also evaluated by means of immunohistochemistry in surgical specimens of patients with astrocytic tumors (<it>n</it> = 64), comparing the expression in tumor patients with (<it>n</it> = 38) and without epilepsy (<it>n</it> = 26).</p> <p>Results</p> <p>Twenty-four hours after onset of SE, Kir4.1 mRNA and protein were significantly down-regulated in temporal cortex of epileptic rats. This decrease in expression was followed by a return to control level at 1 week after SE. The transient downregulation of Kir4.1 corresponded to the time of prominent upregulation of IL-1β mRNA. Expression of Kir4.1 mRNA and protein in glial cells in culture was downregulated after exposure to IL-1β. Evaluation of Kir4.1 in tumor specimens showed a significantly lower Kir4.1 expression in the specimens of patients with epilepsy compared to patients without epilepsy. This paralleled the increased presence of activated microglial cells, as well as the increased expression of IL-1β and the cytoplasmic translocation of high mobility group box 1 (HMGB1).</p> <p>Conclusions</p> <p>Taken together, these findings indicate that alterations in expression of Kir4.1 occurring in epilepsy-associated lesions are possibly influenced by the local inflammatory environment and in particular by the inflammatory cytokine IL-1β.</p

Neuroinflammatory targets and treatments for epilepsy validated in experimental models

A large body of evidence that has accumulated over the past decade strongly supports the role of inflammation in the pathophysiology of human epilepsy. Specific inflammatory molecules and pathways have been identified that influence various pathologic outcomes in different experimental models of epilepsy. Most importantly, the same inflammatory pathways have also been found in surgically resected brain tissue from patients with treatment-resistant epilepsy. New antiseizure therapies may be derived from these novel potential targets. An essential and crucial question is whether targeting these molecules and pathways may result in anti-ictogenesis, antiepileptogenesis, and/or disease-modification effects. Therefore, preclinical testing in models mimicking relevant aspects of epileptogenesis is needed to guide integrated experimental and clinical trial designs. We discuss the most recent preclinical proof-of-concept studies validating a number of therapeutic approaches against inflammatory mechanisms in animal models that could represent novel avenues for drug development in epilepsy. Finally, we suggest future directions to accelerate preclinical to clinical translation of these recent discoveries

Analisi biomolecolare di ceppi di Canine Distemper Virus (CDV) in furetti domestici (Mustela putorius furo)

L\u2019agente eziologico del cimurro (CDV) appartiene alla famiglia Paramyxoviridae, genere Morbillivirus ed \ue8 causa di una patologia infettiva e contagiosa in canidi, mustelidi e procionidi. Gli Autori, descrivono un caso clinico di cimurro in due furetti domestici vaccinati con un ceppo Onderstepoort avianizzato. e la caratterizzazione biomolecolare del CDV isolato. I furetti presentavano un quadro clinico caratterizzato da dermatite pruriginosa e squamo-purulenta, alla regione del mento, peri-labiale, peri-vulvare ed al condotto uditivo esterno. I soggetti venivano a morte tre settimane dopo l\u2019esordio dei sintomi. I campioni di croste prelevati sono stati sottoposti ad estrazione degli acidi nucleici ed analizzati mediante RT-PCR per CDV. E\u2019 stata effettuata l\u2019analisi con enzimi di restrizione (RFLP-PCR) di conferma, per discriminare i ceppi vaccinali dai ceppi di campo. I prodotti di amplificazione sono stati purificati e sottoposti a sequenziamento. Le sequenze di 1823 nt del gene H del CDV sono state comparate mediante Clustal X con analoghe sequenze di ceppi di campo e ceppi vaccinali disponibili su GeneBank. Sulla base dei dati ottenuti le sequenze sono risultate appartenenti al lineage Europa, ben segregato dal lineage America-1, che raccoglie i principali ceppi vaccinali avianizzati, e differente dal cluster dei ceppi Rockborn-like. Il sequenziamento ha confermato il risultato ottenuto con la RFLP-PCR e la mancanza di relazione con il ceppo vaccinale inoculato. Le due sequenze ottenute, presentando un\u2019omologia nucleotidica elevata per ceppi isolati da cani in Italia, sono risultate differenti dal lineage Wildlife. Nel furetto l\u2019infezione da cimurro ha un esito fatale quasi nel 100% dei casi e viene controllata attraverso l\u2019uso di vaccini. Questo lavoro rappresenta un contributo alla esigua disponibilit\ue0 bibliografica in merito alle infezioni da CDV nei mustelidi ed implementa i dati disponibili sui ceppi virali circolanti. Il metodo diagnostico descritto rappresenta un sistema rapido e sensibile per la diagnosi dell\u2019infezione da cimurro