Correlations between charge and energy current in ac-driven coherent conductors

We study transport in coherent conductors driven by a time-periodic bias voltage. We present results of the charge and energy noise and complement them by a study of the mixed noise, namely the zero-frequency correlator between charge and energy current. The mixed noise presents interference contributions and transport contributions, showing features different from those of charge and energy noise. The mixed noise can be accessed by measuring the correlator between the fluctuations of the power provided to the system and the charge current.Comment: 8 pages, 1 figur

Energy and power fluctuations in ac-driven coherent conductors

Using a scattering matrix approach we study transport in coherent conductors driven by a time-periodic bias voltage. We investigate the role of electron-like and hole-like excitations created by the driving in the energy current noise and we reconcile previous studies on charge current noise in this kind of systems. The energy noise reveals additional features due to electron-hole correlations. These features should be observable in power fluctuations. In particular, we show results for the case of a harmonic and bi-harmonic driving and of Lorentzian pulses applied to a two-terminal conductor, addressing the recent experiments of Refs. 1 and 2.Comment: 12 pages, 5 figure

Adiabatic response and quantum thermoelectrics for ac driven quantum systems

We generalize the theory of thermoelectrics to include coherent electron systems under adiabatic ac driving, accounting for quantum pumping of charge and heat as well as the associated work exchange between electron system and driving potentials. We derive the relevant response coefficients in the adiabatic regime and show that they obey Onsager reciprocity relations. We analyze the consequences of our generalized thermoelectric framework for quantum motors, generators, heat engines, and heat pumps, characterizing them in terms of efficiencies and figures of merit.Comment: Published versio

VUZALIZER: A Max/MSP Object for Real-time Generation of RCMC Canons

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Interference and multi-particle effects in a Mach-Zehnder interferometer with single-particle sources

We investigate a Mach-Zehnder interferometer fed by two time-dependently driven single-particle sources, one of them placed in front of the interferometer, the other in the center of one of the arms. As long as the two sources are operated independently, the signal at the output of the interferometer shows an interference pattern, which we analyze in the spectral current, in the charge and energy currents, as well as in the charge current noise. The synchronization of the two sources in this specifically designed setup allows for collisions and absorptions of particles at different points of the interferometer, which have a strong impact on the detected signals. It introduces further relevant time-scales and can even lead to a full suppression of the interference in some of the discussed quantities. The complementary interpretations of this phenomenon in terms of spectral properties and tunable two-particle effects (absorptions and quantum exchange effects) are put forward in this article.Comment: 19 pages, 7 figures, published versio

L’Item Response Theory come strumento di valutazione delle eccellenze nella scuola

According to the modern human capital theory, the learning process is assuming a central role for a country development. Therefore, it is very important to encourage an active and conscious learning. This paper shows the case of the National Olympic of Statistics, that is an initiative to improve statistic reasoning in the Second Grade Middle School. In particular, it has been analyzed, through Item Response Theory models, only one of the competition questionnaires. The aim of this work is to provide a critical review of the questionnaire and to highlight the importance of using statistical methods in evaluation processes

Abnormal temporal coupling of tactile perception and motor action in Parkinson's disease

Evidence shows altered somatosensory temporal discrimination threshold (STDT) in Parkinson's disease in comparison to normal subjects. In healthy subjects, movement execution modulates STDT values through mechanisms of sensory gating. We investigated whether STDT modulation during movement execution in patients with Parkinson's disease differs from that in healthy subjects. In 24 patients with Parkinson's disease and 20 healthy subjects, we tested STDT at baseline and during index finger abductions (at movement onset "0", 100, and 200 ms thereafter). We also recorded kinematic features of index finger abductions. Fifteen out of the 24 patients were also tested ON medication. In healthy subjects, STDT increased significantly at 0, 100, and 200 ms after movement onset, whereas in patients with Parkinson's disease in OFF therapy, it increased significantly at 0 and 100 ms but returned to baseline values at 200 ms. When patients were tested ON therapy, STDT during index finger abductions increased significantly, with a time course similar to that of healthy subjects. Differently from healthy subjects, in patients with Parkinson's disease, the mean velocity of the finger abductions decreased according to the time lapse between movement onset and the delivery of the paired electrical stimuli for testing somatosensory temporal discrimination. In conclusion, patients with Parkinson's disease show abnormalities in the temporal coupling between tactile information and motor outflow. Our study provides first evidence that altered temporal processing of sensory information play a role in the pathophysiology of motor symptoms in Parkinson's disease

Effect of Agronomic Techniques on Aroma Composition of White Grapevines: A Review

Climate change with rising temperatures and the unpredictability of rainy events during ripening leads to tough challenges for the winemakers in preserving the quality of white grape varieties. Grape quality is a complex concept that mainly refers to berry chemical composition, including secondary metabolites such as aroma compounds that in white berries play a key role in the identity of the wine. Terpenes, thiols, C13-norisoprenoids, methoxypyrazines, and nonterpenic alcohols are the most important aroma compounds in white grapes and several of them can be found as free volatiles or bound as glycoconjugate molecules. Agronomic practices in vineyards, such as biostimulant application, irrigation, defoliation, training systems, foliar fertilization, and bunch thinning, can have a positive effect on their concentration. This review aims to highlight the aromatic characteristics of the most utilized white grape cultivars and focus on agronomic techniques in the vineyard to enhance, implement, and intensify their aromatic characteristics. The purpose of this review paper is therefore to investigate the state of the art regarding the exaltation of aroma in white grapes in the scientific literature through sustainable agronomic techniques, but further future investigations are considered necessary given the uncertainty concerning some mechanisms of biosynthesis and their correlation with such agronomic practices

Familial fetal-type rhabdomyoma of the tricuspid valve in the neonate: Malignant course for a benign disease

Familial fetal-type rhabdomyoma of the tricuspid valve in the neonate: malignant course for a benign disease

Middle ear metastasis from dormant breast cancer as the initial sign of disseminated disease 20 years after quadrantectomy.

We describe an unusual case of breast cancer metastatic to the middle ear in a 71-year-old woman. The metastasis was the initial sign of disseminated disease 20 years after the patient had undergone a quadrantectomy for her primary disease. Computed tomography (CT) demonstrated the presence of an intratympanic mass with a soft-tissue density that was suggestive of chronic inflammation. The patient underwent a canal-wall-down tympanoplasty. When a brownish mass was found around the ossicles, a mastoidectomy with posterior tympanotomy was carried out. However, exposure of the tumor was insufficient, and therefore the posterior wall of the ear canal had to be removed en bloc. Some tumor was left on the round window membrane so that we would not leave the patient with a total hearing loss. Our case highlights the limitations of CT and magnetic resonance imaging in differentiating inflammatory and neoplastic lesions