Characterization of a potassium-stimulated ATPase in membrane fraction isolated from roots of grapevine seedlings

A microsomal fraction possessing Mg2+-dependent and K+-stimulated ATPase activity was extracted by differential centrifugation from roots of grape seedlings (Vitis vinifera L. cv. Verduzzo).Roots yield from grape seeds was stimulated by means of GA3 and further improved by treatments able to control microbial contamination.The biochemical characteristics of ATPase activity were studied and compared with those previously reported for roots produced by grape woody cuttings.The presence of choline-Cl, ethanolamine and glycerol-1-P in addition to BSA, EDTA, PVPP and DTT in the homogenizing medium was obligatory in order to record the K+-stimulated component of activity.The enzyme was activated by Mg2+, further stimulated by monovalent ions and showed strong preference for ATP as the substrate and optimum pH at 6.5 in the presence of both Mg2+ and K+. The effect of different monovalent ions followed a sequence similar to that found in cereal roots preparations, but very different with respect to that recorded for preparations from roots of grape woody cuttings.K+-ATPase activity was inhibited by vanadate and DES whereas molybdate and azide had no or scarce effect . ATPase activity showed a simple Michaelis-Menten saturation with increasing ATP: Mg concentration, and a complex pattern of possible negative cooperativity for K+ stimulation.Microsomes fractionated using sucrose density gradient showed enrichment in plasmalemma vesicles at 1.10-1,15 g ml-1 density.This parameter differentiates this fraction from similar preparations containing plasmalemma ATPase obtained from roots of various annual plants

Fonti documentarie e istituzioni culturali nelle città venete dei decenni centrali dell’Ottocento: archivi e biblioteche municipali

Ricerca dedicata alle pratiche di conservazione e ordinamento della documentazione storica medievale e moderna negli archivi municipali delle città venete, prima e dopo l'unit

Operation of a LAr-TPC equipped with a multilayer LEM charge readout

A novel detector for the ionization signal in a single phase LAr-TPC, based on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the traditional anodic wire arrays, has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro. Cosmic muon tracks were detected allowing the measurement of energy deposition and a first determination of the signal to noise ratio. The analysis of the recorded events demonstrated the 3D reconstruction capability of ionizing events in this device in liquid Argon, collecting a fraction of about 90% of the ionization signal with signal to noise ratio similar to that measured with more traditional wire chambersComment: 9 pages, 7 Figure

Cognitive modulation of psychophysical, respiratory and autonomic responses to cold pressor test

In healthy subjects with high hypnotisability (highs) under hypnosis, subjectively effective suggestions for analgesia abolish the increases in blood pressure associated with cold pressor test (cpt) by reducing the peripheral vascular resistance. The aim of the present study was to investigate the effects of the suggestions of analgesia on the responses to cpt in healthy highs (n = 22) and in low hypnotisable participants (lows, n = 22) out of hypnosis. Cpt was administered without (CPT) and with suggestions for analgesia (CPT+AN). Psychophysical (pain intensity, pain threshold, cpt duration (time of immersion) and pain tolerance, defined as the difference between cpt duration and pain threshold), respiratory (amplitude and frequency) and autonomic variables (tonic skin conductance, mean RR interval (RR = 1/heart rate), blood pressure, skin blood flow) were studied. The suggestions for analgesia increased cpt duration and RR in both groups, but decreased pain intensity and enhanced pain threshold only in highs; in both groups they did not modulate systolic blood pressure, tonic skin conductance and skin blood flow; thus, increased parasympathetic activity appears responsible for the heart rate reduction induced by suggestions in both groups. In conclusion, our findings show that suggestions modulate pain experience differentially in highs and lows, and are partially effective also in lows. We hypothesize that the mechanisms responsible for the efficacy of suggestions in healthy lows may be involved also in their efficacy in chronic pain patients with low hypnotisability

Intervista ad Attilio Bartoli Langeli

Intervista a uno dei maggiori diplomatisti italiani del Novecent

Free electron lifetime achievements in Liquid Argon Imaging TPC

A key feature for the success of the liquid Argon imaging TPC (LAr-TPC) technology is the industrial purification against electro-negative impurities, especially Oxygen and Nitrogen remnants, which have to be continuously kept at an exceptionally low level by filtering and recirculating liquid Argon. Improved purification techniques have been applied to a 120 liters LAr-TPC test facility in the INFN-LNL laboratory. Through-going muon tracks have been used to determine the free electron lifetime in liquid Argon against electro-negative impurities. The short path length here observed (30 cm) is compensated by the high accuracy in the observation of the specific ionization of cosmic ray muons at sea level as a function of the drift distance. A free electron lifetime of (21.4+7.3-4.3) ms, namely > 15.8 ms at 90 % C.L. has been observed over several weeks under stable conditions, corresponding to a residual Oxygen equivalent of about 15 ppt (part per trillion). At 500 V/cm, the free electron speed is 1.5 m/ms. In a LAr-TPC a free electron lifetime in excess of 15 ms corresponds for instance to an attenuation of less than 15 % after a drift path of 5 m, opening the way to the operation of the LAr-TPC with exceptionally long drift distances.Comment: 15 pages, 10 figures; Accepted for publication in JINS

A hardware implementation of Region-of-Interest selection in LAr-TPC for data reduction and triggering

Large Liquid Argon TPC detectors in the range of multikton mass for neutrino and astroparticle physics require the extraction and treatment of signals from some 105 wires. In order to enlarge the throughtput of the DAQ system an on-line lossless data compression has been realized reducing almost a factor 4 the data flow. Moreover a trigger system based on a new efficient on-line identification algorithm of wire hits was studied, implemented on the actual ICARUS digital read- out boards and fully tested on the ICARINO LAr-TPC facility operated at LNL INFN Laboratory with cosmic-rays. Capability to trigger isolated low energy events down to 1 MeV visible energy was also demonstrated.Comment: 26 pages, 26 Figure; to be submitted to JINS

A local trigger system for the large LAr-TPC detector

A special dedicated double-rebinning algorithm has been successfully developed in order to extract the physical hit signal from the TPC wires. This solution has been implemented on digital boards, allowing to realize a local trigger able to identify even localized low-energy small events