903 research outputs found
Experimental Test of Entropic Noise-Disturbance Uncertainty Relations for Three-Outcome Qubit Measurements
Information-theoretic uncertainty relations formulate the joint
immeasurability of two non-commuting observables in terms of information
entropies. The trade-off of the accuracy in the outcome of two successive
measurements manifests in entropic noise-disturbance uncertainty relations.
Recent theoretical analysis predicts that projective measurements are not
optimal, with respect to the noise-disturbance trade-offs. Therefore the
results in our previous letter [PRL 115, 030401 (2015)] are outperformed by
general quantum measurements. Here, we experimentally test a tight
information-theoretic measurement uncertainty relation for three-outcome
positive-operator valued measures (POVM), using neutron spin-1/2 qubits. The
obtained results violate the lower bound for projective measurements as
theoretically predicted.Comment: 14 pages, 14 figure
Static NLO susceptibilities: testing approximation schemes against exact results
The reliability of the approximations commonly adopted in the calculation of
static optical (hyper)polarizabilities is tested against exact results obtained
for an interesting toy-model. The model accounts for the principal features of
typical nonlinear organic materials with mobile electrons strongly coupled to
molecular vibrations. The approximations introduced in sum over states and
finite field schemes are analyzed in detail. Both the Born-Oppenheimer and the
clamped nucleus approximations turn out to be safe for molecules, whereas for
donor-acceptor charge transfer complexes deviations from adiabaticity are
expected. In the regime of low vibrational frequency, static susceptibilities
are strongly dominated by the successive derivatives of the potential energy
and large vibrational contributions to hyperpolarizabilities are found. In this
regime anharmonic corrections to hyperpolarizabilities are very large, and the
harmonic approximation, exact for the linear polarizability, turns out totally
inadequate for nonlinear responses. With increasing phonon frequency the role
of vibrations smoothly decreases, until, in the antiadiabatic (infinite
vibrational frequency) regime, vibrations do not contribute anymore to static
susceptibilities, and the purely electronic responses are regained.Comment: 9 pages, including 3 figure
Maximum SINR Synchronization Strategies in Multiuser Filter Bank Schemes
We consider synchronization in a multiuser filter bank uplink system with single-user detection. Perfect user synchronization is not the optimal choice as the intuition would suggest. To maximize performance the synchronization parameters have to be chosen to maximize the signal-to-interference-plus-noise ratio (SINR) at each equalizer subchannel output. However, the resulting filter bank receiver structure becomes complex. Therefore, we consider two simplified synchronization metrics that are based on the maximization of the average SINR of a given user or the aggregate SINR of all users. Furthermore, a relaxation of the aggregate SINR metric allows implementing an efficient multiuser analysis filter bank. This receiver deploys two fractionally spaced analysis stages. Each analysis stage is efficiently implemented via a polyphase filter bank, followed by an extended discrete Fourier transform that allows the user frequency offsets to be partly compensated. Then, sub-channel maximum SINR equalization is used. We discuss the application of the proposed solution to Orthogonal Frequency Division Multiple Access (OFDMA) and multiuser Filtered Multitone (FMT) systems
Synchronization Algorithms and Receiver Structures for Multiuser Filter Bank Uplink Systems
We address the synchronization problem in an uplink multiuser filter bank system. The system differs from orthogonal frequency division multiple access (OFDMA) since it deploys subchannel frequency confined pulses. User multiplexing is still accomplished by partitioning the tones among the active users. Users are asynchronous such that the received signals experience independent time offsets, carrier frequency offsets, and multipath fading. We first consider the synchronization problem in conventional receivers that implement an analysis filter bank with precompensation of the subchannel time and frequency offsets followed by recursive least square linear subchannel equalization. Several correlation metrics that use data training are described. Then, we consider the synchronization problem in a novel multiuser receiver that comprises two efficiently implemented fractionally spaced analysis filter banks. In this receiver, time/frequency compensation can be jointly done for all the users. Despite its lower complexity, we show that it approaches the performance of single-user transmission
Il progetto e la costruzione della Galleria Vittorio Emanuele II: “one of the most magnificent buildings in Europe”,
I tempi del diritto: Crisi climatica e mutamento delle forme giuridiche
In questo contributo si introduce un approccio temporale al diritto come potenzialmente innovativo per la teoria e la pratica giuridica. Si sostiene che un’analisi del rapporto tra diritto e tempo sia cruciale per attuare un decentramento del soggetto convenzionalmente inteso nel diritto moderno occidentale e per concepire strumenti giuridici in grado di riconoscere reti, legami e assemblaggi. L’attuale fase di cambiamento climatico e crisi ecologica viene interpretata come un contesto in cui è possibile ripensare le forme giuridiche fondamentali del diritto moderno, e del diritto privato in particolare, per consentire l’ingresso di temporalità non lineari e non umane nel pensiero e nella tecnica giuridica.This article presents a temporal approach to law as potentially innovative for legal theory and practice. It posits that an analysis of the relationship between law and time is essential in order to decentre the subject of rights as conventionally conceived in Western modern law and to develop legal instruments capable of recognising networks, connections and assemblages. The current phase of climate change and ecological crisis is interpreted as a context in which it is possible to rethink the fundamental forms of modern law, and of private law in particular, in order to allow non-linear and non-human temporalities to enter legal thought and technique
Mindfulness: pratica meditativa, strumento di riabilitazione e approccio terapeutico nei contesti educativi.
Il presente elaborato si prefigge di offrire una panoramica di conoscenze e di esperienze pratiche sul mondo della meditazione mindfulness, calata in particolare nel contesto educativo con bambini e insegnanti. All'interno della tesi vengono analizzati due studi scientifici condotti rispettivamente in due classi quarte di una Scuola Primaria del Friuli Venezia Giulia e su un gruppo di insegnanti di diverse scuole e differenti ordini organizzato dall'Universita degli Studi di Udine.ope
Histological Feature of Ovarian Structures Throughout the Reproductive Cycle in Alpine Goats (Capra Hircus)
AbstractThe knowledge about ovarian physiology in small ruminants is still limited, especially when compared to other domestic species. Ovarian function in goats is mainly assessed by ultrasonographic techniques, whereas a quali-quantitative feature of the follicular and luteal structures throughout the reproductive cycle in naturally cycling goats is scarce. This study provides a detailed description of the functional morphology and size of 742 ovarian structures (follicles, corpora hemorrhagica and corpora lutea) in relation to the oestrus phase, the body weight and the age of 25 Alpine goats (Capra hircus). The current study demonstrated that, the number and size of the follicles were related to the stage of the reproductive cycle (P 4 mm) (P < 0.001), and small follicles (< 2 mm; P < 0.05) varied throughout the reproductive cycle, while medium follicles (2-3 mm) were invariably observed. Large and very large follicles were predominant during the diestrus phase and small follicles in the prepubertal anestrus. It is evident from the current study that the number of follicles (P < 0.05) was significantly affected with both body weight and age. On the other hand, the size of follicles was significantly affected with body weight only (P < 0.0001). These results could contribute to a deeper understanding of ovarian transformations with important implications in assisted reproductive technologies, thereby concurring in advancing the efficiency of ultrasound in breeding programs for this species
Premature Birth with Complicated Perinatal Course Delaying Diagnosis of Prader-Willi Syndrome
Prader-Willi syndrome in the newborn is essentially characterized by marked hypotonia, feeding difficulties, hypogonadism, and possible characteristic facial features. However, diagnosis at this age may be particularly difficult, and dysmorphic features may be subtle or absent. Prematurity can furthermore delay clinical features recognition and typical complications due to preterm birth may contribute to divert the diagnosis. We describe a preterm baby with a complicated perinatal course later diagnosed as PWS
Ethanol Perinatal Exposure Induces Behavioral Alterations and Ethanol Preference in Adolescent Wistar Rats
Ethanol-perinatally-exposed (EPE)Wistar rats show central nervous system morphological alterations that persist until adulthood. The aim of this work was to study whether adolescent EPE rats present alterations in behavior and develop ethanol (EtOH) preference. For behavioral analyses, locomotor and exploratory activity, anxiety and long-term memory standardized tests were performed on 40 to 45 dayold male rats. Another group of rats chose to drink between EtOH and water using the model of preference between two bottles, one with EtOH 6% v/v and the other with water. During eight weeks, the volume of EtOH consumed/kg/day was registered and blood EtOH concentration was determined at the end of the experiment. Results in EPE rats show a decrease in aerial exploration and anxiety, while locomotor activity and long-term memory were not affected. Bothmale and female EPE rats preferred EtOH earlier than control rats, showing a highest level of blood EtOH concentration.Fil: Aronne, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencias "profesor Eduardo de Robertis"; ArgentinaFil: Alimonta Rios, Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencias "profesor Eduardo de Robertis"; ArgentinaFil: Pecile, Andrea Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencias "profesor Eduardo de Robertis"; ArgentinaFil: Brusco, Herminia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencias "profesor Eduardo de Robertis"; Argentin
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