196,348 research outputs found
Hydrogen-implantation ed effetti di anelasticità in metalli di transizione
No full textQuesta memoria contiene la tesi di laurea in Fisica di Alberto Francescutto (Relatore prof. L. Verdini, Corr: prof. P. Ciuti) pubblicata come Rapporto Tecnico dell’Istituto Nazionale di Acustica “O. M. Corbino”
A polariton condensate in a photonic crystal potential landscape
No full textThis work has been supported by the State of Bavaria and the Australian Research Council (ARC). The authors thank M D Fraser, N Y Kim, Y Yamamoto, and V D Kulakovskii for fruitful discussions. This publication was funded by the German Research Foundation (DFG) and the University of Wuerzburg in the funding programme Open Access Publishing.The possibility of investigating macroscopic coherent quantum states in polariton condensates and of engineering polariton landscapes in semiconductors has triggered interest in using polaritonic systems to simulate complex many-body phenomena. However, advanced experiments require superior trapping techniques that allow for the engineering of periodic and arbitrary potentials with strong on-site localization, clean condensate formation, and nearest-neighbor coupling. Here we establish a technology that meets these demands and enables strong, potentially tunable trapping without affecting the favorable polariton characteristics. The traps are based on a locally elongated microcavity which can be formed by standard lithography. We observe polariton condensation with non-resonant pumping in single traps and photonic crystal square lattice arrays. In the latter structures, we observe pronounced energy bands, complete band gaps, and spontaneous condensation at the M-point of the Brillouin zone.Peer reviewe
The use of sub-optimal meadows by Alpine chamois (Rupicapra rupicapra) due to the presence of domestic and/or non-native wild ungulates.
No full textLivestock displace European mouflon from optimal foraging sites
No full textThe conflict between free-ranging livestock and wildlife is a serious conservation concern across rural communities worldwide. Livestock may affect wild herbivores via direct competition for resources due to spatial and diet overlap or via behavioural interference. It is imperative that we disentangle the effects of livestock on wildlife behaviour to obtain an empirical basis able to stir management and conservation decisions. Here, we studied the effect of livestock presence on the habitat selection in a free-ranging European mouflon (Ovis aries musimon) population in Sardinia, where the species is under strict protection. We collected spatial data on mouflon and livestock during two consecutive years to investigate whether the mouflon selection of key feeding grassland sites was negatively impacted by the livestock presence. We found that mouflon preferably selected grassland, and its selection significantly increased when grass was of better quality (greener). We showed that livestock presence led to the displacement of mouflon from such preferred feeding sites, an effect clearly exacerbated by livestock proximity. We indeed found that the selection of grassland by mouflon dropped significantly when the distance between livestock and mouflon was below ~ 650 m, providing a useful management threshold indication. Livestock presence in close proximity displaced mouflon to sub-optimal habitat, and its effects may have negative impact on the population dynamic of this species which is already characterized by low female productivity within harsh Mediterranean environment. Our results give clear management indications aimed at better managing livestock grazing within natural areas to ultimately improve wildlife conservation
The relevance of signal timing in human-robot collaborative manipulation
No full textTo achieve a seamless human-robot collaboration, it is crucial that robots express their intentions without perturbating or interrupting the task that a human partner is performing at that moment. Although it has not received much attention so far, this issue is important when robots assist humans in physical and manipulation tasks. The main question addressed here is whether there is a more appropriate time to inform a human partner that a robot is requesting to pass them an object. This question is posed in a reference scenario where human individuals are involved in a continuous pick-and-place task that cannot be interrupted. Our findings showed that providing a cue at the beginning of a reach-to-grasp movement could severely interfere with the ongoing human action, increasing the number of errors made by humans, slowing down and degrading the smoothness of their arm movement, and deflecting their gaze. These disruptive interferences strongly decreased, until they disappeared, when the robot provided the cue to the human partners shortly after the participants picked up an object, identifying this as the best signaling timing. The results of this work showed how the signaling timing may have a decisive influence on the performances of the human-robot teamwork and contribute to understanding the mechanisms underpinning the phenomenon of cognitive-motor interference in humans
Analysis of ecological factors able to affect horn size in yearling Alpine chamois: the role of the geological substrate in affecting horn growth.
No full textCombining blood flow and tissue Doppler imaging with N-terminal pro-type B natriuretic peptide for risk stratification of clinically stable patients with systolic heart failure
No full textThis study was designed to ascertain whether the combination of Doppler assessment of the ratio of mitral blood flow to myocardial early diastolic velocities (E/E(m) ratio) and plasma N-terminal pro-type B natriuretic peptide (NT-proBNP) testing is useful to better stratify patients with stable systolic heart failure (HF). A total of 362 outpatients with chronic systolic HF (left ventricular ejection fraction = 12), 77% in those with the E/E(m) ratio in the intermediate third, and 86% in those with the E/E(m) ratio in the lower third (< 7) (P < 0.0001). By stratifying patients according to NT-proBNP above the median, patients' outcome was predicted in 13 out of 17 in the intermediate third (P = 0.002) and in 9 out of 10 in the lower third of E/E(m) ratio (P= 0.005). In patients with stable HF categorized according to the E/E(m) ratio, NT-proBNP testing improves risk stratification, particularly in those with minor degrees of diastolic dysfunction
Metal/polymer composite Nuss bar for minimally invasive bar removal after Pectus Excavatum treatment: FEM simulations
No full textThis study aims at assessing the mechanical behavior of a composite metal/polymer bar to be implanted in the retrosternal position, in order to correct chest wall deformities, such as Pectus Excavatum. A 300-mm-long, 12.7-mm-wide, and 3.5-mm-thick Nuss bar was considered, made of different metals and biodegradable polymers, fixed at its extremities, and with a constant force of 250 N applied on its center. Two different geometries for the metal elements to be embedded in the polymeric matrix were tested: in the former, thin metal sheets and in the latter, cylindrical metal reinforcing rods were considered. Finite element method simulation results are reported, in terms of maximum stress and strain of the bar. Furthermore, the maximum stress values obtained by varying metal sheet thickness or rod diameter (and therefore the volumetric percentage of metal within the matrix) for different material combinations are also shown; optimal configuration for the Pectus Excavatum treatment was finally identified for a composite Nuss bar
Electromagnetic control system for capsule endoscope navigation: a novel concept for magnetic capsule maneuvering
No full textTrade-offs between predation risk and food quality re-distribute elk across a road network: not all roads are equal
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