Formal deformations and their categorical general fibre

We study the general fibre of a formal deformation over the formal disk of a projective variety from the view point of abelian and derived categories. The abelian category of coherent sheaves of the general fibre is constructed directly from the formal deformation and is shown to be linear over the field of Laurent series. The various candidates for the derived category of the general fibre are compared. If the variety is a surface with trivial canonical bundle, we show that the derived category of the general fibre is again a linear triangulated category with a Serre functor given by the square of the shift functor

An Egyptian green schist palette and an amazonite gemstone from the “Palace of the Copper Axes” at Batrawy, Jordan

The exploration of the “Palace of the Copper Axes”, the Early Bronze Age III palace of the easternmost city of Southern Levant during the 3rd millennium BC, was resumed in 2018, during the 14th season of excavation at Khirbet al-Batrawy in north-central Jordan, and completed in 2019. In the entrance hall of the palace, a square space with ceilings supported by four pillars, an Egyptian green schist palette, a cyan gemstone of amazonite and a pierced bead of fluorapatite were found buried under the destruction layer, while a barrel-shaped carnelian bead from Mesopotamia was found in the destruction layer just outside the Eastern Pavilion of the palace. These finds again testify to the inclusion of the palace and the city into a wide international trade network and its special connections with Pharaonic Egypt

Abel-Jacobi maps for hypersurfaces and non commutative Calabi-Yau's

It is well known that the Fano scheme of lines on a cubic 4-fold is a symplectic variety. We generalize this fact by constructing a closed p-form with p=2n-4 on the Fano scheme of lines on a (2n-2)-dimensional hypersurface Y of degree n. We provide several definitions of this form - via the Abel-Jacobi map, via Hochschild homology, and via the linkage class, and compute it explicitly for n = 4. In the special case of a Pfaffian hypersurface Y we show that the Fano scheme is birational to a certain moduli space of sheaves on a p-dimensional Calabi--Yau variety X arising naturally in the context of homological projective duality, and that the constructed form is induced by the holomorphic volume form on X. This remains true for a general non Pfaffian hypersurface but the dual Calabi-Yau becomes non commutative.Comment: 34 pages; exposition of Hochschild homology expanded; references added; introduction re-written; some imrecisions, typos and the orbit diagram in the last section correcte

Curva di apprendimento nella scialoendoscopia diagnostica e interventistica per le patologie salivari ostruttive

La scialoendoscopia è un nuovo strumento diagnostico e chirurgico che offre l’opportunità di trattare alcune patologie delle ghiandole salivari con procedure non invasive e con risultati potenzialmente superiori alle precedenti tecniche. Come per tutte le nuove tecniche, per raggiungere rapidamente risultati paragonabili a quelli riportati in letteratura, è indispensabile un corretto programma di formazione che segua una graduale curva di apprendimento. Questo include un appropriato programma diagnostico, una corretta selezione dei pazienti e la conoscenza delle possibili insidie operatorie. Abbiamo eseguito uno studio retrospettivo confrontando le prime 141 procedure (74 parotidee e 67 sottomandibolari) eseguite con questa tecnica nel nostro Dipartimento dal 2009 al 2013 con analoghe esperienze riportate in letteratura. I pazienti sono stati divisi in 3 gruppi: Gruppo A (le prime 49 procedure effettuate), gruppo B (le successive 50), Gruppo C (le ultime 42 procedure effettuate). Fra i tre gruppi non sono state evidenziate differenze statisticamente significative nei tempi medi di durata delle procedure, nella percentuale di ricorrenza della sintomatologia dopo il trattamento, nel numero di pazienti che hanno necessitato di più trattamenti e nell’incidenza di complicanze minori. Non sono state riportate complicanze maggiori. Con l’acquisizione di una maggiore esperienza da parte dei chirurghi si è evidenziato un progressivo calo del numero di interventi eseguiti in anestesia generale rispetto a quelli in anestesia locale (51% vs 18% vs 14%). Solo in tre casi su 130 ghiandole trattate (2.3%) è stato necessario eseguire un’asportazione ghiandolare. Per i calcoli salivari è stato valutato il tipo di tecnica utilizzato per l’estrazione e la percentuale d’insuccesso che era analoga nei tre gruppi (13.6% vs 15% vs 15%). I nostri risultati non differiscono sostanzialmente da quelli riportati in letteratura. Abbiamo risolto la difficoltà iniziale nella cateterizzazione del dotto con esercizi chirurgici su cadavere o su teste di maiale. La mancanza di precisione degli strumenti diagnostici radiologici può essere migliorata autonomizzando il chirurgo nell’esecuzione delle ecografie pre e post-operatorie. Viene infine sottolineata l’opportunità di creare dei centri di scialoendoscopia con un bacino di utenza di circa 1 o 2 milioni di abitanti in modo da concentrare le patologie, far fronte agli elevati costi della strumentazione necessaria e poter guadagnare la necessaria esperienza nelle gestione delle varie tecniche chirurgiche

The depositional record of the Odyssea drift (Ross Sea, Antarctica)

The Ross Sea is one of the major areas for Antarctic Bottom Water formation (the Ross Sea Bottom Water, RSBW), representing the densest ocean water mass, filling the deepest ocean basins connected to the southern ocean. Peri- odic refill of the RSBW occurs through formation of dense, cold and saline water masses (brine) forming on the shelf at the Ross Sea permanent polynya by freezing and salt rejection (high-salinity shelf water, HSSW). The HSSW periodically overspills the shelf area and descends along the slope. This mechanism represents the engine of the global ocean circulation regulating the climate. The Hillary Canyon, crossing the Ross Sea continental slope, represents one of the main conducts through which the HSSW descends the slope to reach the deeper ocean. On its western levee, there is a mounded depocen- tre that was mapped and ground-sampled during the Italian ITRS17-ODYSSEA expedition on board the RV OGS-Explora (January-February 2017). Geophysical data allowed interpreting such feature as a sediment drift (ODYSSEA Drift), generated by along-slope, contour currents sediment transport and accumulation through sev- eral hundred-thousands years. It was inferred that contour currents transported and deposited the sediments that descent the Hillary Canyon by means of the HSSW. Therefore, the depositional sequence of the ODYSSEA Drift potentially contains the record of the variability of HSSW formation, the along slope current intensity in associa- tion to climate change, and the interplay between the two bottom currents. A multidisciplinary investigation was applied to six gravity cores collected in the proximal and distal area of the ODYSSEA Drift. The cores were analysed to reconstruct the age model combining AMS radiocarbon dating on foraminifera tests, biostratigraphy, and the sediment palaeomagnetic record; the sediment physical properties (wet bulk density, water content and grain size); and compositional characteristics (XRF core scan and geochemistry). Three main lithofacies were distinguished and associated to depositional processes and climatic conditions: 1) finely laminated and bioturbated sediments characterized by a relatively high Ca content with common presence of biogenic component. Such facies was associated to contour current deposition during relatively warm conditions. 2) Bioturbated sediments with abundant, sparse and/or layered Ice Rafted Debris, and high Ca content. The onset of this facies is characterized by a prominent Mn peak that was associated to bottom ocean oxygenation through ice sheet melting/decay. 3) Laminated, barren sediments associated to steady strong bottom currents under harsh climate conditions. Further preliminary data interpretations are discussed

Evidence For The Production Of Slow Antiprotonic Hydrogen In Vacuum

We present evidence showing how antiprotonic hydrogen, the quasistable antiproton-proton (pbar-p) bound system, has been synthesized following the interaction of antiprotons with the hydrogen molecular ion (H2+) in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events, evidence is presented for antiprotonic hydrogen production with sub-eV kinetic energies in states around n=70, and with low angular momenta. The slow antiprotonic hydrogen may be studied using laser spectroscopic techniques.Comment: 5 pages with 4 figures. Published as Phys. Rev. Letters 97, 153401 (2006), in slightly different for

Interference Study of the chi_c0 (1^3P_0) in the Reaction Proton-Antiproton -> pi^0 pi^0

Fermilab experiment E835 has observed proton-antiproton annihilation production of the charmonium state chi_c0 and its subsequent decay into pi^0 pi^0. Although the resonant amplitude is an order of magnitude smaller than that of the non-resonant continuum production of pi^0 pi^0, an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. The amplitudes J=0 and 2, of comparable strength, dominate the expansion. Both are accessed by L=1 in the entrance proton-antiproton channel. The product of the input and output branching fractions is determined to be B(pbar p -> chi_c0) x B(chi_c0 -> pi^0 pi^0)= (5.09 +- 0.81 +- 0.25) x 10^-7.Comment: 4 pages, 4 figures, Accepted by PRL (July 2003