Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe

The Extragalactic Background Light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ~10 GeV during propagation from sources at cosmological distances. This results in a redshift- and energy-dependent attenuation of the gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts (GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using photons above 10 GeV collected by Fermi over more than one year of observations for these sources, we investigate the effect of gamma-ray flux attenuation by the EBL. We place upper limits on the gamma-ray opacity of the Universe at various energies and redshifts, and compare this with predictions from well-known EBL models. We find that an EBL intensity in the optical-ultraviolet wavelengths as great as predicted by the "baseline" model of Stecker et al. (2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A. Reimer, L.C. Reye

Apigliano. Un villaggio bizantino e medievale in Terra d’Otranto. I Reperti

Vari articoli che trattano le ricerche sul sito del villaggio medievale abbandonato di Apigliano, Martano (LE

Le ceramiche da fuoco e da cucina

Il contributo analizza i dati relativi alle ceramiche da fuoco e da cucina, rinvenute nella fossa 1 della Torre Mozza del castello di Lecce. Le ceramiche da fuoco e da cucina rientrano nel grup- po dei manufatti ad impasto refrattario. Nel contesto esaminato sono presenti esclusivamente manufatti invetriati, mentre sono del tutto assenti le cosiddette Slip Painted Ware, ossia le invetriate da fuoco con decorazione ad ingobbio, prodotte nel Salento agli inizi del XVII secolo. Le ceramiche da fuoco e da cucina in età rinascimentale si pongono in sostanziale continuità rispetto alle produzioni bassomedievali; ciò che caratterizza i materiali di questo periodo è l’uso della vetrina su tutti i manufatti, sia su quelli destinati direttamente alla cottura, sia su quelli utilizzati solo per la preparazione dei cibi. Tutti i contenitori rinvenuti nello scarico sono di produzione locale, con molta probabilità realizzati nelle stesse botteghe urbane. L’analisi delle caratteristiche morfologiche, tipologiche e di impasto, permette di avanzare l’ipotesi circa le modalità di produzione delle officine locali. Dato l’elevato grado di standardizzazione rilevato nella morfologia delle diverse forme è possibile pensare ad una produzione manifatturiera specializzata. Per ciò che concerne le forme, il corredo da cucina rinvenuto è costituito da dieci forme, delle quali tre utilizzate per la cottura dei cibi (pentole, pignatte e tegami/casseruole), quattro per la consumazione (tazze, bicchieri, bottiglie e brocche), e tre per la preparazione (microvasetti, ciotole, oliere/brocche)

Le ceramiche acrome e acrome incise

Il contributo analizza i dati relativi alle ceramiche comuni acrome e acrome incise, rinvenute nella fossa 1 della Torre Mozza del castello di Lecce. La ceramica comune rinvenuta appartiene a contenitori in impasto depurato privi di rivestimento vetroso distinti in ceramica acroma, incisa, dipinta e dipinta incisa. Le ceramiche acrome e quelle con decorazione incisa, sono realizzate con impasti depurati o semi depurati, molto probabilmente realizzati con argille il cui bacino di approvvigionamento è esclusivamente locale; le caratteristiche principali degli impasti corrispondono a quelle note in letteratura per l’area pugliese e, in particolare, salentina. Le ceramiche acrome presentano un ventaglio di forme più articolato rispetto alle incise e alle dipinte. Sono stati individuati diversi contenitori di grandi dimensioni, come la giara, medie come i pitali, le anfore e le olle e vasi più piccoli come le borracce e i mortai. Tra le forme chiuse è singolare la presenza della borraccia, un tipo di contenitore che generalmente si trova nella veste invetriata, graffita o smaltata e quasi mai del tutto acroma. Le borracce prodotte nel Salento, infatti, sono rivestite e decorate, ma dalla fossa 1 del castello provengono diversi esemplari non rivestiti e completamente privi di decorazione. Nel gruppo delle ceramiche con funzionalità domestiche prive di rivestimento si annovera anche un gruppo di reperti con decorazione incisa a crudo. Si tratta di manufatti esclusivamente di forma chiusa e con un repertorio morfologico ridotto a due sole forme, l’anforetta e la fiasca. Stando quindi ai dati archeologici a disposizione è possibile datare le ceramiche acrome con decorazione incisa a partire dal XV secolo, probabilmente con una produzione ancora poco attestata che, invece, sarà incrementata nel XVI. Nei secoli successivi sia le forme che le decorazioni incise continueranno ad essere prodotte in maniera costante e senza particolari variazioni, affiancate però da simili manufatti in veste invetriata o smaltata

Perioperative evaluation of myastenia gravis

A. Cardone, E. Congedo, P, Aceto, R. Sicuranza, E. Chinè, F. Caliandro, G. De Cosmo Ann.Ital.Chir 2007; Vol. 78 / 5 – pag. 359-366 Myasthenia gravis (MG) is the prototype of antibody mediated autoimmune disease and results from the production of autoantibodies against the acetylcholine receptor (AChR) of the neuromuscular synapse. Adequate preoperative evaluation of the myasthenic patient must be carried out carefully. Age, sex, onset and duration of the disease as well as the presence of thymoma may determine the response to thymectomy. Specific attention should be paid to voluntary and respiratory muscle strength. The preoperative preparation of MG patients is essential for the success of surgery. It depends on the severity of clinical status and changes if myasthenic patients receive anticholinesterase therapy. Myasthenic patients may have little respiratory reserve, and hence depressant drugs for preoperative premedication should be used with caution and avoided in patients with bulbar symptoms. The anaesthetic management of myasthenic patient must be individualized in according to the severity of the disease and the type of surgery required. The use of regional or local anaesthesia seems warranted whenever possible. General anaesthesia can be performed safely when patient is optimally prepared and neuromuscular transmission is adequately monitored during and after surgery. Adequate postoperative pain control, pulmonary toilet, and avoidance of drugs that interfere with neuromuscular transmission will facilitate tracheal extubation. Myasthenia gravis is a disease with many implications for the safe administration of anaesthesia. The potential for respiratory compromise in these patients requires the anaesthesiologist to be familiar with the underlying disease state, as well as the interaction of anaesthetic and non-anaesthetic drugs with MG

Highly selective luminescent nanostructures for mitochondrial imaging and targeting

Here a luminescent hybrid nanostructure based on functionalized quantum dots (QDs) is used as a fluorescent imaging agent able to target selectively mitochondria thanks to the molecular recognition of the translocator protein (TSPO). The selective targeting of such an 18 kDa protein mainly located in the outer mitochondrial membrane and overexpressed in several pathological states including neurodegenerative diseases and cancers may provide valuable information for the early diagnosis and therapy of human disorders. In particular, the rational design of amino functionalized luminescent silica coated QD nanoparticles (QD@SiO2 NPs) provides a versatile nanoplatform to anchor a potent and selective TSPO ligand, characterized by a 2-phenyl-imidazo[1,2-a] pyridine acetamide structure along with a derivatizable carboxylic end group, useful to conjugate the TSPO ligand and achieve TSPO-QD@SiO2 NPs by means of a covalent amide bond. The colloidal stability and optical properties of the proposed nanomaterials are comprehensively investigated and their potential as mitochondrial imaging agents is fully assessed. Subcellular fractionation, together with confocal laser scanning fluorescence microscopy and co-localization analysis of targeted TSPO-QD@SiO2 NPs in C6 glioma cells overexpressing the TSPO, proves the great potential of these multifunctional nanosystems as in vitro selective mitochondrial imaging agents

Risk factors for intracerebral hemorrhage in patients with atrial fibrillation on NOACs for stroke prevention

Background and Purpose: Clinical trials on stroke prevention in patients with atrial fibrillation have consistently shown clinical benefit from either warfarin or non–vitamin K antagonist oral anticoagulants (NOACs). NOAC-treated patients have consistently reported to be at lower risk for intracerebral hemorrhage (ICH) than warfarin-treated patients. The aims of this prospective, multicenter, multinational, unmatched, case-control study were (1) to investigate for risk factors that could predict ICH occurring in patients with atrial fibrillation during NOAC treatment and (2) to evaluate the role of CHA2DS2-VASc and HAS-BLED scores in the same setting. Methods: Cases were consecutive patients with atrial fibrillation who had ICH during NOAC treatment. Controls were consecutive patients with atrial fibrillation who did not have ICH during NOAC treatment. As within the CHA2DS2-VASc and HAS-BLED scores there are some risk factors in common, several multivariable logistic regression models were performed to identify independent prespecified predictors for ICH events. Results: Four hundred nineteen cases (mean age, 78.8±8.1 years) and 1526 controls (mean age, 76.0±10.3 years) were included in the study. From the different models performed, independent predictors of ICH were increasing age, concomitant use of antiplatelet agents, active malignancy, high risk of fall, hyperlipidemia, low clearance of creatinine, peripheral artery disease, and white matter changes. Low doses of NOACs (given according to label or not) and congestive heart failure were inversely associated with the risk of ICH. HAS-BLED and CHA2DS2-VASc scores performed poorly in predicting ICH with areas under the curves of 0.496 (95% CI, 0.468-0.525) and 0.530 (95% CI, 0.500-0.560), respectively. Conclusions: Several risk factors were associated to ICH in patients treated with NOACs for stroke prevention but not HAS-BLED and CHA2DS2-VASc scores

The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission

40 pages, 7 tables, 33 figures, emulateapj.cls; submitted to The Astrophysical Journal(Abridged) The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy gamma-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. This paper describes the LAT, its pre-flight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4x4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 x,y tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an 8 layer hodoscopic configuration with a total depth of 8.6 radiation lengths. The aspect ratio of the tracker (height/width) is 0.4 allowing a large field-of-view (2.4 sr). Data obtained with the LAT are intended to (i) permit rapid notification of high-energy gamma-ray bursts (GRBs) and transients and facilitate monitoring of variable sources, (ii) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (iii) measure spectra from 20 MeV to more than 50 GeV for several hundred sources, (iv) localize point sources to 0.3 - 2 arc minutes, (v) map and obtain spectra of extended sources such as SNRs, molecular clouds, and nearby galaxies, (vi) measure the diffuse isotropic gamma-ray background up to TeV energies, and (vii) explore the discovery space for dark matter