The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new reference

APOE ɛ4 exacerbates age-dependent deficits in cortical microstructure

The apolipoprotein E ɛ4 allele is the primary genetic risk factor for the sporadic type of Alzheimer’s disease. However, the mechanisms by which apolipoprotein E ɛ4 are associated with neurodegeneration are still poorly understood. We applied the Neurite Orientation Dispersion Model to characterize the effects of apolipoprotein ɛ4 and its interactions with age and education on cortical microstructure in cognitively normal individuals. Data from 1954 participants were included from the PREVENT-Dementia and ALFA (ALzheimer and FAmilies) studies (mean age = 57, 1197 non-carriers and 757 apolipoprotein E ɛ4 carriers). Structural MRI datasets were processed with FreeSurfer v7.2. The Microstructure Diffusion Toolbox was used to derive Orientation Dispersion Index maps from diffusion MRI datasets. Primary analyses were focused on (i) the main effects of apolipoprotein E ɛ4, and (ii) the interactions of apolipoprotein E ɛ4 with age and education on lobar and vertex-wise Orientation Dispersion Index and implemented using Permutation Analysis of Linear Models. There were apolipoprotein E ɛ4 × age interactions in the temporo-parietal and frontal lobes, indicating steeper age-dependent Orientation Dispersion Index changes in apolipoprotein E ɛ4 carriers. Steeper age-related Orientation Dispersion Index declines were observed among apolipoprotein E ɛ4 carriers with lower years of education. We demonstrated that apolipoprotein E ɛ4 worsened age-related Orientation Dispersion Index decreases in brain regions typically associated with atrophy patterns of Alzheimer’s disease. This finding also suggests that apolipoprotein E ɛ4 may hasten the onset age of dementia by accelerating age-dependent reductions in cortical Orientation Dispersion Index

Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set

This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of 3He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active 8B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54-0.31+0.33(stat.)-0.34+0.36(syst.)×106 cm-2 s-1, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Δm2=7.59-0.21+0.19×10 -5eV2 and θ=34.4-1.2+1.3degrees

Evoluzione storica delle misure orarie in Italia

The present paper represents a research on the historical evolution,<br />in Italy, regarding the measurement of hours during the day. A few<br />cosmographical theoric recalls are offered to clarify how the problem<br />should be considered from the astronomical viewpoint. A review is then<br />made of the different chronometrical scales adopted in Italy, since Roman<br />times; then, later, in the High and Low Medieval periods down to<br />modern and contemporary times. All the different chronometrical scales<br />adopted, in their historical evolution, are investigated: temporary, equinoctial,<br />Italian hours, true local, mean local, civil, time hours a.m. and<br />p.m., mean Rome, Mean Central European, Universal and finally Universally<br />Coordinate, time hours; the intermittent adoption of legal summer<br />time, is recalled.<br />The importance of the problem is evidenced on account of the repercussion<br />that an inaccurate interpretation of the different time measures<br />given in historical times can have on geophysical events, and especially on an indexing of seismic events occurring in epochs prior to the<br />existence of radiosignalled time.<br />To illustrate the research, reference is made to the classical treatise<br />of Baratta «1 terremoti d'ltalia » (ed. 1901): possibility of alterations of<br />the fina lresults can be observed unless special attention is given to the<br />original chronicles. The alterations can even produce a date change<br />or a repetition, in the same catalogue, of the same event.<br />Reliability criteria are suggested for hour data in function of the<br />epoch of the event, as well as for the chronometrical scale employed in<br />evidencing said event.<br />In appendix some passages drawn from a study made by Serpieri<br />on the Rimini earthquake of March 18, 1875 that confirm tre difficulties<br />evidence are reported.<br />Some tables are also reported:<br />a table that gives the start of the clay for the calculation of Italian<br />hours at different latitude sand at different days of the year, prior to<br />and after the Gregorian reformation of the calendar, as well as the<br />corresponding time equations (App. E);<br />a table that gives the geoghaphical coordinates of the Italian<br />provincial capitals with the longitudes (referred to Greenwich and Rome)<br />expressed in time (App. D);<br />a table showing time periods where legal (summer) time was<br />adopted instead of solar time (App. B);<br />a table of intercalar seconds of Universal Coordinate time (App. A)