Change Detection Performance in Naturalistic Scenes: The Influence of Visual Working Memory for Identity and Spatial Locations

The present studies examined the roles of identity and spatial working memory in change detection. Observers completed a spatial or identity working memory task concurrently with a change detection task. In the change detection task, participants were presented naturalistic scenes that contained either a color or location change to one object. Concurrently, participants remembered either the colors or locations of four squares. There was specific disruption of performance when the working memory task and the change detection task loaded the same subsystem of working memory. There was also evidence that spatial information is processed more readily than identity information. This suggests that although there are separate systems for identity and spatial working memory, these subsystems are not necessarily created equal in that processing in the spatial processing may have priority over identity processing. However, this priority can be overridden during change detection if spatial memory is already occupied

Silicon Photo-Multiplier radiation hardness tests with a beam controlled neutron source

We report radiation hardness tests performed at the Frascati Neutron Generator on silicon Photo-Multipliers, semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated integrating up to 7x10^10 1-MeV-equivalent neutrons per cm^2. Detector performances have been recorded during the neutron irradiation and a gradual deterioration of their properties was found to happen already after an integrated fluence of the order of 10^8 1-MeV-equivalent neutrons per cm^2.Comment: 7 pages, 6 figures, Submitted to Nucl. Inst. Meth.

Search for Neutron Flux Generation in a Plasma Discharge Electrolytic Cell

Following some recent unexpected hints of neutron production in setups like high-voltage atmospheric discharges and plasma discharges in electrolytic cells, we present a measurement of the neutron flux in a configuration similar to the latter. We use two different types of neutron detectors, poly-allyl-diglicol-carbonate (PADC, aka CR-39) tracers and Indium disks. At 95% C.L. we provide an upper limit of 1.5 neutrons cm^-2 s^-1 for the thermal neutron flux at ~5 cm from the center of the cell. Allowing for a higher energy neutron component the largest allowed flux is 64 neutrons cm^-2 s^-1. This upper limit is two orders of magnitude smaller than what previously claimed in an electrolytic cell plasma discharge experiment. Furthermore the behavior of the CR-39 is discussed to point our possible sources of spurious signals.Comment: 4 pages, 3 figure

Diversity of S-Alleles and Mate Availability in 3 Populations of Self-Incompatible Wild Pear (Pyrus pyraster)

Small populations of self-incompatible plants may be expected to be threatened by the limitation of compatible mating partners (i.e., S-Allee effect). However, few empirical studies have explicitly tested the hypothesis of mate limitation in small populations of self-incompatible plants. To do so, we studied wild pear (Pyrus pyraster), which possesses a gametophytic self-incompatibility system. We determined the S-genotypes in complete samplings of all adult trees from 3 populations using a PCR-RFLP approach. We identified a total of 26 different S-alleles, homologous to S-alleles of other woody Rosaceae. The functionality of S-alleles and their Mendelian inheritance were verified in artificial pollination experiments and investigations of pollen tube growth. The smallest population (N = 8) harbored 9 different S-alleles and showed a mate availability of 92.9%, whereas the 2 larger populations harbored 18 and 25 S-alleles and exhibited mate availabilities of 98.4% and 99.2%, respectively. Therefore, we conclude that even small populations of gametophytic self-incompatible plants may exhibit high diversity at the S-locus and are not immediately threatened owing to reduced mate availabilit

Neutron spectrometer for fast nuclear reactors

In this paper we describe the development and first tests of a neutron spectrometer designed for high flux environments, such as the ones found in fast nuclear reactors. The spectrometer is based on the conversion of neutrons impinging on $^6$Li into $\alpha$ and $t$ whose total energy comprises the initial neutron energy and the reaction $Q$-value. The $^6$LiF layer is sandwiched between two CVD diamond detectors, which measure the two reaction products in coincidence. The spectrometer was calibrated at two neutron energies in well known thermal and 3 MeV neutron fluxes. The measured neutron detection efficiency varies from 4.2$\times 10^{-4}$ to 3.5$\times 10^{-8}$ for thermal and 3 MeV neutrons, respectively. These values are in agreement with Geant4 simulations and close to simple estimates based on the knowledge of the $^6$Li(n,$\alpha$)$t$ cross section. The energy resolution of the spectrometer was found to be better than 100 keV when using 5 m cables between the detector and the preamplifiers.Comment: submitted to NI

Application of genetic markers to the discrimination of European Black Poplar ( Populus nigra ) from American Black Poplar ( P. deltoides ) and Hybrid Poplars ( P. x canadensis ) in Switzerland

European Black Poplar (Populus nigra) is considered a rare and endangered tree species because of severe reduction of its natural riverine habitat and potential hybridisation with the related non-indigenous taxa P. deltoides and P. x canadensis. As it is difficult to distinguish these taxa solely based on their morphology, we applied a PCR-based assay with an easy-to-use and robust molecular marker set (cpDNA trnL-trnF/RsaI RFLP, nDNA win3 and nDNA POPX/MspI RFLP) in order to identify pure P. nigra. Different plant tissues could be used for fast and standardised DNA extraction. The application of the three marker types was tested on a number of different Populus taxa, and they were also used for the verification of pure P. nigra in a sample of 304 putative P. nigra individuals from Switzerland. Cross-checking of the DNA data with those using a traditional allozyme approach resulted in complete agreement. The availability of molecular identification methods is an important prerequisite for the conservation of European Black Poplar, because pure, non-introgressed plant material can then be used in restoration projects of European floodplain

Intrinsic Dimension of Path Integrals: Data-Mining Quantum Criticality and Emergent Simplicity

Quantum many-body systems are characterized by patterns of correlations defining highly nontrivial manifolds when interpreted as data structures. Physical properties of phases and phase transitions are typically retrieved via correlation functions, that are related to observable response functions. Recent experiments have demonstrated capabilities to fully characterize quantum many-body systems via wave-function snapshots, opening new possibilities to analyze quantum phenomena. Here, we introduce a method to data mine the correlation structure of quantum partition functions via their path integral (or equivalently, stochastic series expansion) manifold. We characterize path-integral manifolds generated via state-of-the-art quantum Monte Carlo methods utilizing the intrinsic dimension (ID) and the variance of distances between nearest-neighbor (NN) configurations: the former is related to data-set complexity, while the latter is able to diagnose connectivity features of points in configuration space. We show how these properties feature universal patterns in the vicinity of quantum criticality, that reveal how data structures simplify systematically at quantum phase transitions. This is further reflected by the fact that both ID and variance of NN distances exhibit universal scaling behavior in the vicinity of second-order and Berezinskii-Kosterlitz-Thouless critical points. Finally, we show how non-Abelian symmetries dramatically influence quantum data sets, due to the nature of (noncommuting) conserved charges in the quantum case. Complementary to neural-network representations, our approach represents a first elementary step towards a systematic characterization of path-integral manifolds before any dimensional reduction is taken, that is informative about universal behavior and complexity, and can find immediate application to both experiments and Monte Carlo simulations

The preparation of the Shutdown Dose Rate experiment for the next JET Deuterium-Tritium campaign

The assessment of the Shutdown Dose Rate (SDR) due to neutron activation is a major safety issue for fusion devices and in the last decade several benchmark experiments have been conducted at JET during Deuterium-Deuterium experiments for the validation of the numerical tools used in ITER nuclear analyses. The future Deuterium-Tritium campaign at JET (DTE2) will provide a unique opportunity to validate the codes under ITER-relevant conditions through the comparison between numerical predictions and measured quantities (C/E). For this purpose, a novel SDR experiment, described in the present work, is in preparation in the frame of the WPJET3-NEXP subproject within EUROfusion Consortium. The experimental setup has been accurately designed to reduce measurement uncertainties; spherical air-vented ionization chambers (ICs) will be used for on-line ex-vessel decay gamma dose measurements during JET shutdown following DT operations and activation foils have been selected for measuring the neutron fluence near ICs during operations. Active dosimeters (based on ICs) have been calibrated over a broad energy range (from about 30 keV to 1.3 MeV) with X and gamma reference beam qualities. Neutron irradiation tests confirmed the capability of active dosimeters of performing on-line decay gamma dose rate measurements, to follow gamma dose decay at the end of neutron irradiation as well as insignificant activation of the ICs

clinical and functional outcome in a subject with bipolar disorder and severe white matter hyperintensities

Background and Objectives: Neuroimaging studies have found higher rates of white matter hyperintensities (WMHs) in patients with bipolar disorder (BD) of all ages, although whether BD is associated with increased rates of WMHs independently from age and cerebrovascular risk factors is still matter of debate. The outcome of BD associated with severe WMHs is generally poor, but several authors have suggested that some factors could have a protective role in BD. The aim of the present study was to report the two-year follow-up of a woman with BD type I and severe WMH/PWMH lesions who was taking high concentrations of vitamin-D in her nutrition, as well as taking lithium and haloperidol as treatment. Case presentation: A 76-year-old woman was hospitalized for a mixed state BD. She had severe WMHs. She took lithium and haloperidol during the hospitalization and was euthymic at discharge as well as after two-years of follow-up. Her nutrition had a high concentration of Vitamin-D. Unfortunately, it was not possible to give her a second MRI. Conclusions: Although there was probable persistence of WMHs, the patient improved in both mood and quality of life. The possible protective effect of lithium and Vitamin-D is discussed. Received: 12 January 2010 Revised: 5 August 2010 Accepted: 14 September 2010 Short report 42 GIANLUCA SERAFINI ET AL. Background and objectives Neuroimaging studies have found higher rates of WMHs in patients of all ages with bipolar disorder (BD), most frequently localized in the frontal lobes and the frontal/parietal junction1. WMHs may indicate astrogliosis, demyelination and loss of axons and may be relatively more common in older patients with BD, reflecting an interaction of the disease with processes of normal aging. However, WMHs are also associated with several pathological conditions among older individuals2. As a result of this, the meaning of these lesions in BD is still unclear. Although there have been inconsistent results in the research on this issue, WMHs are considered to be negative prognostic factors, associated with treatment resistance, increased hospitalization rates, cognitive impairment and increased suicide risk in individuals with BD3,4. However, several other factors may play a protective role in BD. Tsai et al.5 reported that psychiatric treatment, including medication with antipsychotics or lithium, could be a protective factor against early natural death. Here, we present the case of a 76year-old woman who had had a BD for twenty-one years and had, in addition, severe WMH/PWMH lesions, who was admitted to our psychiatric hospital for a mixed state. The patient gave written consent before being included in the study