1,721,100 research outputs found
Entanglement estimation in non-optimal qubit states
Full text linkThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordIn the last years, a relationship has been established between the quantum Fisher information (QFI) and quantum entanglement. In the case of two-qubit systems, all pure entangled states can be made useful for sub-shot-noise interferometry while their QFI meets a necessary and sufficient condition (Hyllus et al., 2010). In M-qubit systems, the QFI provides just a sufficient condition in the task of detecting the degree of entanglement of a generic state (Pezzé and Smerzi, 2009). In our work, we show analytically that, for a large class of one-parameter non-optimal two-qubit states, the maximally entangled states are associated with stationary points of the QFI, as a function of such parameter. We show, via numerical simulations, that this scenario is maintained for the generalisation of this class of states to a generic M-qubit system. Furthermore, we suggest a scheme for an interferometer able to detect the entanglement in a large class of two-spin states.QuantERAEuropean Commissio
Podarcis muralis (Laurenti, 1768)(Lucertola muraiola
No full textScheda per il monitoraggio della Lucertola Muraiola ai fini delle direttive europe
Aspetti eco-etologici della testuggine alloctona Trachemys scripta: quali influenze sulla conservazione della testuggine europea Emys orbicularis?.
No full text(Abstract
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Keeping a cool mind: head–body temperature differences in the common wall lizard
Full text linkEvidence of head–body temperature differences are known for many species of medium- to large-sized reptiles, but are scanty for small lacertid lizards. In this study, we heated 48 individuals ofPodarcis muralis(19 males and 29 females) in order to investigate their ability to achieve and maintain local temperature differ-ences between body parts. Lizards were put into polystyrene boxes and heated with incandescent lamps. Temperatures were measured with both an infrared thermometer and an infrared camera at four different body points every 20 min for 2 h. We found a statistically significant thermal gradient from the tip of the nose, the coolest part of the body, to the trunk, the warmest area, whereas the head achieved an intermediate temperature. We therefore hypothesize that P. muralisis able to physiologically regulate the heat distribution across its body. Podarcis muralisis sexually dimorphic, but neither sex nor body size are associated with temperature differences between individuals. The two measurement devices used responded differently to insulating material and to living animals, possibly indicating that infrared camera is able to detect dermal heat, while infrared thermometer detects mainly epidermal heat. This study shows for the first time that P. muraliscan achieve and maintain temperature differences between the head and the body
Combining N-mixture models with ecological niche modeling supplies a low-cost and fast procedure for estimating population size in remote areas
No full textMonitoring population changes and trends is a central task in conservation. However, obtaining detailed information for wide and low accessible areas, such as remote islands, is challenging, and cannot be achieved with conventional approaches, such as capture-mark-recapture protocols (CMR). In this paper, we show that combining N-mixture models with ecological niche modeling allows assessing reliable estimates of population size over large target areas on short time intervals. We used it to estimate the population size of a subspecies of the Italian wall lizards (Podarcis siculus calabresiae) endemic to the Island of Montecristo (10.39 km(2) in surface). During a single week, we first generated a niche model of the species based on satellite images sampled few days before sampling. Then, we estimated lizard abundance through Bayesian N-mixture models on repeated counts (n=3) along transects (n=6), settled in different areas of habitat suitability defined on the basis of the niche model. Finally, we estimated in approximately 20.000 the total number of lizards living in the Island by extrapolating the values computed on transects to the areas of the islands with the same suitability estimated by the niche model. The procedure can be easily repeated allowing monitoring the status of conservation of the species in the island of Montecristo. More in general, this procedure has the potential to be applied to monitor any other species of conservation interest in remote areas whenever detailed satellite images are available.[GRAPHICS]
Parliamone a “mente fredda”: l'uso della termocamera nello studio della termoregolazione dei rettili.
No full textSpecies distribution modelling as a conservation tool: the case study of Vipera aspis in a highly exploited region
Full text linkVipera aspis is quite common in hilly and mountainous area of Northern Italy but is becoming rare in the Po plain with few exceptions along main rivers. The reasons for such a distribution seem related to the progressive reduction of suitable habitat due to human landscape modifications, rather than to specific ecological needs. In this scenario, the knowledge of the exact distribution of this species and the identification of the factors which still make some planitial areas suitable would be very useful for conservation strategies. So the aims of this work are: i) modelling a distribution map of the potential suitable areas to focus surveys efforts and spatial relations with protected areas; ii) identifying the most important factors which affect suitability. The study area was the plain area of Lombardy that covered about 14100 km2 and was defined by 300 m a.s.l. contour line. The 45 occurrence data came from various research projects from 2000 to 2009. Fourteen non-correlated potential predictors were included in the model: six bioclimatic variables (http://www.worldclim.org/); five environmental (land use; density of cultivated fields); three anthropic (fresh water level of fungicide and organochlorine, roads density). All the variables were resampled to 100 m spatial resolution. Potential distribution was modelled using the maximum entropy method, and performed by the software MAXENT 3.3.1 (http://www.cs.princeton.edu/~schapire/maxent/). We used the bootstrap procedure to generate ten different models each with 25% of localities as test sample. We then averaged single model results. The models fit well (mean training AUC: 0.981 ± 0.008; mean testing AUC: 0.942 ± 0.032). The suitable area at the 10th percentile threshold is 3.4% of the study area and is reduced to its North-Western part, with few and isolated spots elsewhere. Fifty-six percent of suitable cells falls within protected areas, and most of the remaining part is nearby. The most informative variables are land use and roads density, which together explain 56.1% of observed variance. Suitability is positively affected by woods and meadows, and negatively by anthropic structures and increasing roads density. Our results demonstrate that asp viper is a species at risk in the Po plain, due to habitat fragmentation and modifications caused by anthropic activities. The north-western part of the study area plays a key role in its conservation thanks to more natural conditions and to a higher protection level. It is fundamental to preserve this territory and to increase the connectivity among existing natural parks
Indagini paletnologiche su un insediamento neolitico in località Le Macchie (Polignano a Mare - Bari)
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