Prospects for Gamma-Ray Bursts detection by the Cherenkov Telescope Array

The first Gamma-Ray Burst (GRB) catalog presented by the Fermi-Large Area Telescope (LAT) collaboration includes 28 GRBs, detected above 100 MeV over the first three years since the launch of the Fermi mission. However, more than 100 GRBs are expected to be found over a period of six years of data collection thanks to a new detection algorithm and to the development of a new LAT event reconstruction, the so-called "Pass 8." Our aim is to provide revised prospects for GRB alerts in the CTA era in light of these new LAT discoveries. We focus initially on the possibility of GRB detection with the Large Size Telescopes (LSTs). Moreover, we investigate the contribution of the Middle Size Telescopes (MSTs), which are crucial for the search of larger areas on short post trigger timescales. The study of different spectral components in the prompt and afterglow phase, and the limits on the Extragalactic background light are highlighted. Different strategies to repoint part of - or the entire array - are studied in detail.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC 2015), The Hague, The Netherland

Implant survival and success rates in patients with risk factors: results from a long-term retrospective study with a 10 to 18 years follow-up

OBJECTIVE: Risk factors for implant therapy are represented by all general and local conditions that through various mechanisms can increase either short-term and long-term failure risk. The aim of this study is to assess the implant survival and implant success rates with single and multiple risk factors. PATIENTS AND METHODS: To address the research purpose, a retrospective cohort study was designed and implemented, including a sample of 225 patients with a total of 871 implants placed. The following risk factors were considered: smoking, bruxism, bone augmentation procedures and the presence of load risk (implants with crown/implant relation > 0.8; angulation > 25°; presence of cantilever). Follow-up ranged from 10 years to 18 years (average follow-up 13.6 years). Failures were subdivided into short-term failures, before the prosthetic phase, and long-term failures, after definitive prosthesis. The success criteria published by Albrektsson and Zarb were adopted. A Cox proportional hazard regression model was used to calculate hazard ratio, with a statistically significant p-value <0.05. RESULTS: Out of the 871 implants placed, 138 did not meet the success criteria, (success rate 84.16%), sixty (43.47%) were classified as "early failure" and seventy-eight as "late failure" (56.53%). A total of 70 dental implants were removed, with a survival rate of 91.96%. CONCLUSIONS: The presence of a single risk factor does not imply a marked increase of failure risk. Among the analyzed factors, the one that proved to be the most dangerous was bruxism, even when presented as the only risk factor. Bruxism with load risk proved to be the most dangerous association (success rate 69.23%) and could be included among the absolute contraindications for implant treatment

A randomized clinical trial about presence of pathogenic microflora and risk of peri-implantitis: comparison of two different types of implant-abutment connections

OBJECTIVE: The aim of this in vivo study was to evaluate two different types of implant-abutment connections: screwed connection and cemented connection, analyzing peri-implant bacteria microflora as well as other clinical parameters. PATIENTS AND METHODS: Twenty implants were selected, inserted in 20 patients, 10 with a screwed implant-abutment connection (Group 1) and 10 with a cemented implant-abutment connection (Group 2). The peri-implant microflora was collected, after at least 360 days from the prosthetic rehabilitation, using paper points inserted in peri-implant sulcus for 30 s. Polymerase chain reaction (PCR) Real-time analyzed the presence of 9 bacteria periodontal-pathogens and Candida albicans. RESULTS: Our findings showed that bacteria colonized all Groups analyzed, the average bacterial count was 3.7 E +08 (±1.19) in Group 1, compared to 2.1 E +08 (±0.16) in Group 2; no statistically significant differences were observed (p>0.0.5). In Group 1, however, bacterial colonization of peri-implant sulci was over the pathogenic threshold for 5 bacteria, indicating a high-risk of peri-implantitis. Also in Group 2, results showed a microflora composed by all bacteria analyzed but, in this case, bacterial colonization of peri-implant sulci was over the pathogenic threshold for only 1 bacterium, indicating a lower risk of peri-implantitis. Moreover, clinical parameters (PPD > 3 mm and m SBI > 0) confirmed a greater risk of peri-implantitis in Group 1 compared to Group 2 (p<0.05). CONCLUSIONS: We concluded that, also after only 360 days, implants with screwed connection showed a higher risk of peri-implantitis that implants with cemented connection

Brain function monitoring during off-pump cardiac surgery: a case report

BACKGROUND: Early postoperative stroke is an adverse syndrome after coronary bypass surgery. This report focuses on overcoming of cerebral ischemia as a result of haemodynamic instability during heart enucleation in off-pump procedure. CASE PRESENTATION: A 67 year old male patient, Caucasian race, with a body mass index of 28, had a recent non-Q posterolateral myocardial infarction one month before and recurrent instable angina. His past history includes an uncontrolled hypertension, dyslipidemia, insulin dependent diabetes mellitus, epiaortic vessel stenosis. The patient was scheduled for an off-pump procedure and monitored with bilateral somatosensory evoked potentials, whose alteration signalled the decrement of the cardiac index during operation. The somatosensory evoked potentials appeared when the blood pressure was increased with a pharmacological treatment. CONCLUSION: During the off-pump coronary bypass surgery, a lower cardiac index, predisposes patients, with multiple stroke risk factors, to a reduction of the cerebral blood flow. Intraoperative somatosensory evoked potentials monitoring provides informations about the functional status of somatosensory cortex to reverse effects of brain ischemia

Prospects for Gamma-Ray Bursts detection by the Cherenkov Telescope Array

The first Gamma-Ray Burst (GRB) catalog presented by the Fermi-Large Area Telescope (LAT) collaboration includes 28 GRBs, detected above 100 MeV over the first three years since the launch of the Fermi mission. However, more than 100 GRBs are expected to be found over a period of six years of data collection thanks to a new detection algorithm and to the development of a new LAT event reconstruction, the so-called "Pass 8." Our aim is to provide revised prospects for GRB alerts in the CTA era in light of these new LAT discoveries. We focus initially on the possibility of GRB detection with the Large Size Telescopes (LSTs). Moreover, we investigate the contribution of the Middle Size Telescopes (MSTs), which are crucial for the search of larger areas on short post trigger timescales. The study of different spectral components in the prompt and afterglow phase, and the limits on the Extragalactic background light are highlighted. Different strategies to repoint part of - or the entire array - are studied in detail

A heterogeneous subcontinental mantle under the African–Arabian plate boundary revealed by boron and radiogenic isotopes

The northern and northwestern margins of the Arabian Plate are a locus of a diffuse and long-lasting (early Miocene to Pleistocene) Na-alkali basaltic volcanism, sourced in the asthenosphere mantle. The upwelling asthenosphere at the Africa–Arabia margin produces very limited magma volumes in the axial zone. Therefore, portions of hot, fertile mantle continue their eastward migration and are stored at shallower depths under the 100-km thick Arabian lithosphere, which is much thinner than the African one (≈175 km): this causes the occurrence and 20-Ma persistence of magma supply under the study area. Erupted basalts sampled a continuous variation of the mantle source, with a striking correlation among temperature, pressure and isotopic composition shifting between two end-members: a 100 km-deep, more depleted source, and a 60 km-deep, more enriched one. In particular, we observed an unusual variation in boron isotopes, which in the oceanic domain does not vary between more depleted and more enriched mantle sources. This study shows that, at least in the considered region, subcontinental mantle is more heterogeneous than the suboceanic one, and able to record for very long times recycling of shallow material

Earthquakes trigger the loss of groundwater biodiversity

Earthquakes are among the most destructive natural events. The 6 April 2009, 6.3-Mw earthquake in L\u27Aquila (Italy) markedly altered the karstic Gran Sasso Aquifer (GSA) hydrogeology and geochemistry. The GSA groundwater invertebrate community is mainly comprised of small-bodied, colourless, blind microcrustaceans. We compared abiotic and biotic data from two pre-earthquake and one post-earthquake complete but non-contiguous hydrological years to investigate the effects of the 2009 earthquake on the dominant copepod component of the obligate groundwater fauna. Our results suggest that the massive earthquake-induced aquifer strain biotriggered a flushing of groundwater fauna, with a dramatic decrease in subterranean species abundance. Population turnover rates appeared to have crashed, no longer replenishing the long-standing communities from aquifer fractures, and the aquifer became almost totally deprived of animal life. Groundwater communities are notorious for their low resilience. Therefore, any major disturbance that negatively impacts survival or reproduction may lead to local extinction of species, most of them being the only survivors of phylogenetic lineages extinct at the Earth surface. Given the ecological key role played by the subterranean fauna as decomposers of organic matter and "ecosystem engineers", we urge more detailed, long-term studies on the effect of major disturbances to groundwater ecosystems

Le trasformazioni dello spazio urbano: la quarta dimensione nella georeferenziazione dell’iconografia storica di Rome

Se si considera la componente fisica del sistema città come espressione materiale dell’insieme dei fenomeni evolutivi dei luoghi, appare evidente come la sua rappresentazione possa essere considerata come sistema di conoscenza generale in grado di manifestare una convergenza di informazioni di natura altamente eterogenea. Le vaste trasformazioni che hanno interessato le città nella storia hanno determinato una evoluzione non solo nelle modifiche morfologiche degli assetti territoriali e nella stratificazione architettonica delle strutture urbane, ma anche nella percezione e fruizione degli spazi urbani. Se si considera l’organizzazione dello spazio urbano come ambito di relazione tra gli uomini, i contributi che provengono dalle fonti bibliografiche, iconografiche e cartografiche in particolare possono consentire la ricostruzione diacronica dei tessuti urbani. Questa ricostruzione è resa possibile dalla lettura delle diverse rappresentazioni che della città sono state date nel tempo, come rappresentazioni iconografiche o pittoriche, talvolta simboliche se non addirittura metaforiche, che consentono di acquisire conoscenze dei luoghi, anche quando presentano uno scarso grado di attendibilità. L’introduzione dell’informatica nel rilevamento e nella rappresentazione cartografica e la realizzazione dei sistemi informativi territoriali hanno aperto nuove possibilità non solo nella realizzazione di database collegati e georeferenziati, che possono contenere una notevole quantità di informazioni di diversa natura progressivamente incrementabili, ma soprattutto rendendo agevoli sia le molteplici interrogazioni sia le successive elaborazioni. Lo sviluppo della cartografia digitale dalla quale si possono derivare direttamente modelli tridimensionali, si pone quindi come punto di partenza per una corretta rappresentazione della complessità del fenomeno urbano e per un ripensamento dello spazio non più sulla base di esplorazioni planimetriche, ma tramite la creazione di modelli virtuali generati in maniera più o meno automatica a partire dalla cartografia stessa. In questo senso, il modello di derivazione cartografica costituisce l’aspetto metrico-quantitativo della rappresentazione della città, aspetto che risulta tanto più esatto, obiettivo e verificabile in quanto ottenuto con strumenti che rendono le misurazioni sufficientemente attendibili. Si tratta dunque di esplorare la cartografia tridimensionale cogliendone le peculiarità e la ricchezza nella restituzione dello spazio urbano, caratteristiche, queste, che suggeriscono immediatamente di tentare di ricostruire con la stessa vivacità rappresentativa anche tutti i trascorsi storici della città o, quanto meno, di alcuni dei suoi momenti topici, con particolare attenzione alle trasformazioni di natura orografica ed edilizia. In questo quadro emergono due distinti aspetti di natura metodologica, l’uno concernente la generazione del modello urbano e le implicazioni tecniche che questo comporta (implementazione di dati, automatismi, studi tipo-morfologici, scala del modello, …), l’altro relativo all’evoluzione della città attraverso il confronto tra modelli cartografici diversi (bi e tridimensionali). La realizzazione di un modello virtuale basato sulla cartografia digitale 3D, che fotografa lo stato attuale della struttura urbana, può rappresentare la griglia tridimensionale di riferimento per una visualizzazione delle trasformazioni spaziali attuata con una procedura che ripercorre a ritroso il cammino della storia. Si tratta di riferire a questa griglia orientata sulla base di capisaldi topografici certi i dati cartografici e iconografici provenienti dalla ricerca storico-documentaria, sulla base della individuazione di elementi invarianti della struttura urbana, come assetti orografici, vuoti urbani o edifici esistenti, etc., che non hanno mutato la loro localizzazione e le loro caratteristiche morfologiche. Così concepito, il modello tridimensionale di derivazione cartografica si caratterizza per la capacità di recepire e valorizzare documenti molto diversi e non necessariamente “scientifici” ai fini di una visualizzazione interattiva della storia del singolo brano di città o del singolo edificio per valutarne le trasformazioni sul piano morfologico e dimensionale, ma anche percettivo.Peer Reviewe