Silicon Drift Detector Readout Electronics for a Compton Camera

A prototype detector for Compton camera imaging is under development. A monolithic array of 19 channel Silicon drift detector with on-chip electronics is going to be used as a scatter detector for the prototype system. Custom designed analog and digital readout electronics for this detector was first tested by using a single cell Silicon drift detector. This paper describes the readout architecture and presents the results of the measurement.Comment: 10 pages, 9 figures, submitted to Nucl. Instr. Meth.

ADAGSS: Automatic Dataset Generation for Semantic Segmentation

A common issue in medical deep learning research is the creation of dataset for training the neural networks. Medical data collection is also tied-up by privacy laws and even if a lot of medical data are available, often their elaboration can be time demanding. This problem can be avoided using neural networks architectures that can achieve a good predicting precision with few images (e.g. U-Net). In the case of semantic segmentation, the dataset generation is even more cumbersome since it requires the creation of segmentation masks manually. Some automatic ground-truth creation techniques may be employed like filtering, thresholding and Self Organized Maps1 (SOM). These automatic methods can be very powerful and useful, but they always have a bottle-neck phase: data validation. Due to algorithm reliability (that sometimes can fail), data needs to be validated manually before they can be included in a dataset for training. In this work, we propose a method to automatize this phase by moving manual intervention to an easier task: instead of creating masks and then validate them manually, we train a convolutional neural network to classify segmentation quality. Therefore, the validation is performed automatically. An initial manual phase is still required, but the classification task requires a smaller number of elements in the dataset that will feed a network employed for classification. After this phase, similar dataset creations will require less effort. This procedure is based on the fact that to obtain a high classification precision, fewer data are required than the data that are needed to obtain high precision in semantic segmentation. High classification score, can automatize validation procedure in dataset creation, being able to discard failure case in dataset creation. Being able to produce bigger dataset in less time can led to higher precision in semantic segmentation

Characterization of paralic paleoenvironments using benthic foraminifera from early Cretaceous deposits (Scotian Shelf)

Abstrac

Land take and landscape loss: Effect of uncontrolled urbanization in Southern Italy

The present paper describes a research that, based on the evolutionary data of the urban settlement over a period of half a century, shows the changes undergone by the various landscape categories of Southern Italy. The regions involved are four (Campania, Basilicata, Puglia and Calabria) and share renowned urban, economic and social issues such as unauthorised development, low income per capita and organised crime. All this has produced profound transformations on some of the most important and rare Italian landscapes, such as coastal plains and coastal carbonate slabs. Uncontrolled urban sprawl has further provoked an environmental crisis and eco-friendly insularisation of the yet numerous and valuable protected areas of this geographical area, thus leading to a high density of buildings and infrastructures even in national parks, breaking European records in this respect. Through finalised indicators, the characteristics of the evolution occurred have been analytically highlighted, and by using the latest generation satellite data, it is shown how such phenomena have continued to take place with significant energy over the last few years. The result is a picture of environmental threats still very prominent in this southern extremity of the peninsula, above all towards those naturalistic qualities and landscapes that are the main attractions of an intense national and international tourism whose income, however, has not been conveyed in a correct and inclusive way to allow high-level socio-economic conditions of the resident population. Keywords: Urban growth, Land take, Landscape loss, Urban sprinkling, South Ital

Enabling matter power spectrum emulation in beyond-ΛCDM cosmologies with COLA

We compare and validate COLA (COmoving Lagrangian Acceleration) simulationsagainst existing emulators in the literature, namely Bacco and Euclid Emulator2. Our analysis focuses on the non-linear response function, i.e., the ratiobetween the non-linear dark matter power spectrum in a given cosmology withrespect to a pre-defined reference cosmology, which is chosen to be the EuclidEmulator 2 reference cosmology in this paper. We vary three cosmologicalparameters, the total matter density, the amplitude of the primordial scalarperturbations and the spectral index. By comparing the COLA non-linear responsefunction with those computed from each emulator in the redshift range $0 \leq z\leq 3$, we find that the COLA method is in excellent agreement with the twoemulators for scales up to $k \sim 1 \ h$/Mpc as long as the deviations of thematter power spectrum from the reference cosmology are not too large. Wevalidate the implementation of massive neutrinos in our COLA simulations byvarying the sum of neutrino masses to three different values, $0.0$ eV, $0.058$eV and $0.15$ eV. We show that all three non-linear prescriptions used in thiswork agree at the $1\%$ level at $k \leq 1 \ h$/Mpc. We then introduce theEffective Field Theory of Dark Energy in our COLA simulations using the$N$-body gauge method. We consider two different modified gravity models inwhich the growth of structure is enhanced or suppressed at small scales, andshow that the response function with respect to the change of modified gravityparameters depends weakly on cosmological parameters in these models.<br

Nucleon decay and atmospheric neutrinos in the Mont Blanc experiment

In the NUSEX experiment, during 2.8 years of operation, 31 fully contained events have been collected; 3 among them are nucleon decay candidates, while the others have been attributed to upsilon interactions. Limits on nucleon lifetime and determinations of upsilon interaction rates are presented

A bolometric measurement of the antineutrino mass

High statistics calorimetric measurements of the beta spectrum of 187Re are being performed with arrays of silver perrhenate crystals operated at low temperature. After a modification of the experimental set-up, which allowed to substantially reduce the background of spurious counts and therefore to increase the sensitivity on the electron antineutrino mass, a new measurement with 10 silver perrhenate microbolometers is running since July 2002. The crystals have masses between 250 and 350 micrograms and their average FWHM energy resolution, constantly monitored by means of fluorescence X-rays, is of 28.3 eV at the beta end-point. The Kurie plot collected during 4485 hours x mg effective running time has an end-point energy of 2466.1 +/- 0.8{stat} +/- 1.5 {syst} eV, while the half lifetime of the decay is found to be 43.2 +/- 0.2{stat} +/- 0.1{syst} Gy. These values are the most precise obtained so far for 187Re. From the fit of the Kurie plot we can deduce a value for the squared electron antineutrino mass m(nu)^2 of 147 +/- 237{stat} +/- 90{syst} eV^2. The corresponding 90% C.L. upper limit for m(nu) is 21.7 eV.Comment: 3 pages, 3 figures. Submitted to Phys. Rev. Let