41 research outputs found

    Saproxylic beetles of conservation interest in the Calabrian side of the Pollino National Park (Calabria, Italia): Lucanus tetraodon Thunberg, 1806, Osmoderma italicum Sparacio, 2000, Cerambyx cerdo Linnaeus, 1758 and Rosalia alpina (Linnaeus, 1758) (Coleoptera Lucanidae Cetoniidae Cerambycidae)

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    In this article an update on the distribution of Coleoptera Lucanus tetraodon Thunberg, 1806 (Lucanidae), Osmoderma italicum Sparacio, 2000 (Cetoniidae), Cerambyx cerdo Linnaeus, 1758 and Rosalia alpina (Linnaeus, 1758) (Cerambycidae) in the Calabrian side of the Pollino National Park is described. Data regarding the ecological part and the conservation status will be presented for each species. Therefore, of particular interest it can be noted: the presence in nine locations of L. tetraodon, an uncommon species and with little-known distribution; the discreet diffusion of O. italicum, rare and with a very restricted area, found in thirteen locations up to over 1800 m of altitude; C. cerdo for the Calabrian side of the National Park of Pollino; the first data for the presence of R. alpina at 1900 m altitude, the highest recorded in Italy and the discovery of larval stages on Italian alder (Alnus cordata), never ascertained in Italy. The Pollino National Park is confirmed as one of the areas of greatest national importance for the conservation of these xylophagous species linked to old forests

    Inhibition of electromagnetically induced absorption due to excited state decoherence in Rb vapor

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    The explanation presented in [Taichenachev et al, Phys. Rev. A {\bf 61}, 011802 (2000)] according to which the electromagnetically induced absorption (EIA) resonances observed in degenerate two level systems are due to coherence transfer from the excited to the ground state is experimentally tested in a Hanle type experiment observing the parametric resonance on the % D1 line of 87^{87}Rb. While EIA occurs in the F=1→F′=2F=1\to F^{\prime}=2 transition in a cell containing only RbRb vapor, collisions with a buffer gas (30torr30 torr of NeNe) cause the sign reversal of this resonance as a consequence of collisional decoherence of the excited state. A theoretical model in good qualitative agreement with the experimental results is presented.Comment: 8 pages, 7 figures, submitted to Physical Review

    A neural model of number interval position effect (Nipe) in children

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    In the present paper we describe an artificial neural model of the Number Interval Position Effect (NIPE;[5]) that has been observed in the mental bisection of number intervals both in adults and in children. In this task a systematic error bias in the mental setting of the subjective midpoint of number intervals is found, so that for intervals of equal size there is a shift of the subjective midpoint towards numbers higher than the true midpoint for intervals at the beginning of decades while for intervals at the end of decades the error bias is directionally reversed towards numbers lower than the true midpoint. This trend of the bisection error is recursively present across consecutive decades. Here we show that a neural-computational model based on information spread by energy gradients towards accumulation points based on the logarithimic compressed representation of numbermagnitudes that has been observed at the single cell level in rhesus monkeys [9] effectively simulates the performance of adults and children in the mental bisection of number intervals, in particular replicating the data observed in children

    Dissociation between line bisection and mental-number-line bisection in healthy adults

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    Healthy adults bisect visual horizontal lines slightly to the left of their true center. This bias has been termed \u201cpseudoneglect\u201d and is considered to reflect right hemisphere dominance in the orienting of spatial attention. A previous investigation reported a positive correlation between pseudoneglect and a corresponding negative bias towards numbers lower than the true midpoint, i.e. supposedly to the left of the midpoint, during the mental bisection of number intervals that were defined by two visual arabic digits presented one to the left and one to the right of a horizontal line (Longo and Lourenco, 2007, Neuropsychologia, 45, 7, 1400\u20131407). Here, studying a sample of 60 healthy participants we verified whether this correlation still holds when the endpoints of number intervals are defined verbally, i.e. with no visual-spatial cues suggesting their left-to-right arrangement. Participants bisected horizontal lines (2 cm, 10 cm and 20 cm), short number intervals (3-, 5-, 7- and 9-unit) and large number intervals (16-, 24-, 32-, 40-, 48-, 56-, and 64-unit). Pseudoneglect was observed both in line and number interval bi- section, confirming the results of Longo and Lourenco (2007). Nonetheless, the study of correlations between bisection biases averaged across different line and number intervals lengths and between all possible pairings of line and number interval lengths revealed no significant or systematic pattern. During line bisection pseudoneglect increased as a function of line length while with short number intervals pseudoneglect decreased and turned into an opposite positive bias as a function of interval length. With large number intervals no linear relationship was present between bisection bias and in- terval length and, as in Longo and Lourenco (2007), the higher was the starting point of the number interval the larger was pseudoneglect. These results show that verbally defined number intervals are not mentally inspected with the same mechanisms that are engaged by the bisection of horizontal visual lines. This suggests that number intervals are not inherently arranged along the mental equivalent of a left-to-right oriented horizontal line. This spatial representation seems rather adopted when, as in the case of the SNARC task, \u201cleft\u201d vs. \u201cright\u201d codes must be used for the selection of responses associated with numbers or when, as in the case of Longo and Lourenco (2007), the numerical material to be processed is arranged in left-to-right order

    Expectancy modulates pupil size during endogenous orienting of spatial attention

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    fMRI investigations in healthy humans have documented phasic changes in the level of activation of the right temporal-parietal junction (TPJ) during cued voluntary orienting of spatial attention. Cues that correctly predict the position of upcoming targets in the majority of trials, i.e., predictive cues, produce higher deactivation of the right TPJ as compared with non-predictive cues. Since the right TPJ is the recipient of noradrenergic (NE) innervation, it has been hypothesised that changes in the level of TPJ activity are matched with changes in the level of NE activity. Based on aforementioned fMRI findings, this might imply that orienting with predictive cues is matched with different levels of NE activity as compared with non-predictive cues. To test this hypothesis, we measured changes in pupil dilation, an indirect index of NE activity, during voluntary orienting of attention with highly predictive (80% validity) or non-predictive (50% validity) cues. In agreement with current interpretations of the tonic/phasic activity of the Locus Coeruleus-Norepinephrinic system (LC-NE), we found that the steady level of cue predictiveness that characterised both the predictive and non-predictive conditions caused, across consecutive blocks of trials, a progressive decrement in pupil dilation during the baseline-fixation period that anticipated the cue period. With predictive cues we observed increased pupil dilation as compared with non-predictive cues. In addition, the relative reduction in pupil size observed with non-predictive cues increased as a function of cue-duration. These results show that changes in the predictiveness of cues that guide voluntary orienting of spatial attention are matched with changes in pupil dilation and, putatively, with corresponding changes in LC-NE activit

    Cingulate neglect in humans: Disruption of contralesional reward learning in right brain damage

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    Motivational valence plays a key role in orienting spatial attention. Nonetheless, clinical documentation and understanding of motivationally based deficits of spatial orienting in the human is limited. Here in a series of one group-study and two single-case studies, we have examined right brain damaged patients (RBD) with and without left spatial neglect in a spatial reward-learning task, in which the motivational valence of the left contralesional and the right ipsilesional space was contrasted. In each trial two visual boxes were presented, one to the left and one to the right of central fixation. In one session monetary rewards were released more frequently in the box on the left side (75% of trials) whereas in another session they were released more frequently on the right side. In each trial patients were required to: 1) point to each one of the two boxes; 2) choose one of the boxes for obtaining monetary reward; 3) report explicitly the position of reward and whether this position matched or not the original choice. Despite defective spontaneous allocation of attention toward the contralesional space, RBD patients with left spatial neglect showed preserved contralesional reward learning, i.e., comparable to ipsilesional learning and to reward learning displayed by patients without neglect. A notable exception in the group of neglect patients was L.R., who showed no sign of contralesional reward learning in a series of 120 consecutive trials despite being able of reaching learning criterion in only 20 trials in the ipsilesional space. L.R. suffered a cortical-subcortical brain damage affecting the anterior components of the parietal-frontal attentional network and, compared with all other neglect and non-neglect patients, had additional lesion involvement of the medial anterior cingulate cortex (ACC) and of the adjacent sectors of the corpus callosum. In contrast to his lateralized motivational learning deficit, L.R. had no lateral bias in the early phases of attentional processing as he suffered no contralesional visual or auditory extinction on double simultaneous tachistoscopic and dichotic stimulation and detected, with no exception, single contralesional visual and auditory stimuli. In a separate study, we were able to compare L.R. with another RBD patient, G.P., who had a selective lesion in the right ACC, in the adjacent callosal connections and the medial-basal prefrontal cortex. G.P. had no contralesional neglect and displayed normal reward learning both in the left and right side of space. These findings show that contralesional reward learning is generally preserved in RBD patients with left spatial neglect and that this can be exploited in rehabilitation protocols. Contralesional reward learning is severely disrupted in neglect patients when an additional lesion of the ACC is present: however, as demonstrated by the comparison between L.R. and G.P. cases, selective unilateral lesion of the right ACC does not produce motivational neglect for the contralesional space

    Spatiotemporal mechanisms of coexistence in an European mammal community in a protected area of southern Italy

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    Assessing the spatiotemporal overlap amongst animal species living in sympatry helps to shed light on mechanisms of interspecific coexistence. We analysed the spatiotemporal coexistence in a predator–prey system through multiyear camera trapping, in a mountainous protected area of southern Italy (January 2012–January 2017). Temporal activity patterns and their interspecific overlap, as well as spatial overlap, were estimated for a top predator, that is the wolf Canis lupus, three species of wild ungulates, four mesocarnivores, one small herbivore, livestock and humans. A wide nocturnal temporal overlap was detected between the wolf and almost all the other species (71–91%). The highest temporal (91%) and spatial (63%) overlaps were reported between the wolf and the red fox Vulpes vulpes. For wolf-ungulate pairs, the highest temporal overlap (88%) was reported for the wild boar Sus scrofa, its local main prey. Considering all the other species pairs, spatial overlap was low (i.e. lower than 45%), whereas temporal overlap was substantial (71–91%). Our findings support a significant role of interspecific spatial partitioning in shaping coexistence amongst considered species, which might be influenced by differences in spatial distribution of different food resources

    Cingulate neglect in humans: disruption of contralesional reward learning in right brain damage

    No full text
    Clinical documentation and understanding of motivationally based deficits of spatial orienting in the human is limited. Here in a series of one group-study and two single-case studies, we have examined right brain damaged patients (RBD) with and without left spatial neglect in a spatial reward-learning task, in which the motivational valence of the left contralesional and the right ipsilesional space was contrasted. Despite defective spontaneous allocation of attention toward the contralesional space, RBD patients with left spatial neglect showed preserved contralesional reward learning, i.e., comparable to ipsilesional learning and to reward learning displayed by patients without neglect. A notable exception in the group of neglect patients was L.R., who showed no sign of contralesional reward learning. L.R. suffered a cortical-subcortical brain damage affecting theanterior components of the parietal-frontal attentional network and, compared with all other neglect and non-neglect patients, had additional lesion involvement of the medial anterior cingulate cortex (ACC) and of the adjacent sectors of the corpus callosum. In contrast to his lateralized motivational learning deficit, L.R. had no lateral bias in the early phases of attentional processing. These findings show that contralesional reward learning is generally preserved in RBD patients with left spatial neglect and that this can be exploited in rehabilitation protocols. Contralesional reward learning is severely disrupted in neglect patients when an additional lesion of the ACC is present
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