349 research outputs found

    Spontaneous rhythm discrimination in a mammalian vocal learner

    Get PDF
    Rhythm and vocal production learning are building blocks of human music and speech. Vocal learning has been hypothesized as a prerequisite for rhythmic capacities. Yet, no mammalian vocal learner but humans have shown the capacity to flexibly and spontaneously discriminate rhythmic patterns. Here we tested untrained rhythm discrimination in a mammalian vocal learning species, the harbour seal (Phoca vitulina). Twenty wild-born seals were exposed to music-like playbacks of conspecific call sequences varying in basic rhythmic properties. These properties were called length, sequence regularity, and overall tempo. All three features significantly influenced seals' reaction (number of looks and their duration), demonstrating spontaneous rhythm discrimination in a vocal learning mammal. This finding supports the rhythm–vocal learning hypothesis and showcases pinnipeds as promising models for comparative research on rhythmic phylogenies

    Neuropsychological changes in isolated REM sleep behavior disorder: A systematic review and meta-analysis of cross-sectional and longitudinal studies

    Get PDF
    The aim of this meta-analysis is twofold: (a) to assess cognitive impairments in isolated rapid eye movement (REM) sleep behavior disorder (iRBD) patients compared to healthy controls (HC); (b) to quantitatively estimate the risk of developing a neurodegenerative disease in iRBD patients according to baseline cognitive assessment. To address the first aim, cross-sectional studies including polysomnography-confirmed iRBD patients, HC, and reporting neuropsychological testing were included. To address the second aim, longitudinal studies including polysomnography-confirmed iRBD patients, reporting baseline neuropsychological testing for converted and still isolated patients separately were included. The literature search was conducted based on PRISMA guidelines and the protocol was registered at PROSPERO (CRD42021253427). Cross-sectional and longitudinal studies were searched from PubMed, Web of Science, Scopus, and Embase databases. Publication bias and statistical heterogeneity were assessed respectively by funnel plot asymmetry and using I2. Finally, a random-effect model was performed to pool the included studies. 75 cross-sectional (2,398 HC and 2,460 iRBD patients) and 11 longitudinal (495 iRBD patients) studies were selected. Cross-sectional studies showed that iRBD patients performed significantly worse in cognitive screening scores (random-effects (RE) model = –0.69), memory (RE model = –0.64), and executive function (RE model = –0.50) domains compared to HC. The survival analyses conducted for longitudinal studies revealed that lower executive function and language performance, as well as the presence of mild cognitive impairment (MCI), at baseline were associated with an increased risk of conversion at follow-up. Our study underlines the importance of a comprehensive neuropsychological assessment in the context of iRBD

    Electron-phonon renormalization in small Fermi energy systems

    Full text link
    The puzzling features of recent photoemission data in cuprates have been object of several analysis in order to identity the nature of the underlying electron-boson interaction. In this paper we point out that many basilar assumptions of the conventional analysis as expected to fail in small Fermi energy systems when, as the cuprates, the Fermi energy EFE_{\rm F} is comparable with the boson energy scale. We discuss in details the novel features appearing in the self-energy of small Fermi energy systems and the possible implications on the ARPES data in cuprates.Comment: 4 pages, 5 eps figures include

    Long-term effects of a multidisciplinary treatment of uncomplicated obesity on carotid intima-media thickness

    Get PDF
    Obesity is associated with well-known cardiovascular risk factors and a lower life expectancy. This study investigated whether nonoperative nutritional treatment of obesity without comorbidities influenced the carotid intima-media thickness (c-IMT) in the long run. Fifty-four subjects of an original cohort of 251 subjects were re-evaluated 10 years after a medical nutritional treatment (MNT) with cognitive-behavioral approach for uncomplicated obesity. Forty subjects were classified as failure (10-year body weight change >0.5 kg) and 14 (body weight change 640.5 kg) as a success of the MNT. Ten years after MNT, c-IMT significantly increased (0.06 \ub1 0.02 mm; P = 0.004) in the failure group and significantly decreased ( 120.07 \ub1 0.03 mm; P = 0.027) in the success group. Ten-year change in c-IMT correlated significantly with 10-year change in body weight (r = 0.28; P = 0.040). Multiple stepwise linear regression analysis demonstrated that age, final BMI, and group (success or failure) influenced independently the 10-year c-IMT. In conclusion, this study is in agreement with the possibility that the successful MNT of obesity may be an effective choice in the long run and seems to indicate that it may be able to reduce the cardiovascular risk as reflected by the change in c-IMT

    Hamiltonian Dynamics and the Phase Transition of the XY Model

    Full text link
    A Hamiltonian dynamics is defined for the XY model by adding a kinetic energy term. Thermodynamical properties (total energy, magnetization, vorticity) derived from microcanonical simulations of this model are found to be in agreement with canonical Monte-Carlo results in the explored temperature region. The behavior of the magnetization and the energy as functions of the temperature are thoroughly investigated, taking into account finite size effects. By representing the spin field as a superposition of random phased waves, we derive a nonlinear dispersion relation whose solutions allow the computation of thermodynamical quantities, which agree quantitatively with those obtained in numerical experiments, up to temperatures close to the transition. At low temperatures the propagation of phonons is the dominant phenomenon, while above the phase transition the system splits into ordered domains separated by interfaces populated by topological defects. In the high temperature phase, spins rotate, and an analogy with an Ising-like system can be established, leading to a theoretical prediction of the critical temperature TKT0.855T_{KT}\approx 0.855.Comment: 10 figures, Revte

    Risk perception and media in shaping protective behaviors: insights from the early phase of COVID-19 Italian outbreak

    Get PDF
    In the absence of target treatments or vaccination, the SARS-CoV-2 pandemic can be impeded by effectively implementing containment measures and behaviors. This relies on individuals’ adoption of protective behaviors, their perceived risk, and the use and trust of information sources. During a health emergency, receiving timely and accurate information enables individuals to take appropriate actions to protect themselves, shaping their risk perception. Italy was the first western country plagued by COVID-19 and one of the most affected in the early phase. During this period, we surveyed 2,223 Italians before the national lockdown. A quarter of the sample perceived COVID-19 less threatening than flu and would not vaccinate, if a vaccine was available. Besides, most people perceived containment measures, based on social distancing or wearing masks, not useful. This perceived utility was related to COVID-19 threat perception and efficacy beliefs. All these measures were associated with the use of media and their truthfulness: participants declared to mainly use the Internet, while health organizations’ websites were the most trusted. Although social networks were frequently used, they were rated lower for trustfulness. Our data differ from those obtained in other community samples, suggesting the relevance to explore changes across different countries and during the different phases of the pandemic. Understanding these phenomena, and how people access the media, may contribute to improve the efficacy of containment measures, tailoring specific policies and health communications

    Thyroid Hormone T3 Counteracts STZ Induced Diabetes in Mouse

    Get PDF
    This study intended to demonstrate that the thyroid hormone T3 counteracts the onset of a Streptozotocin (STZ) induced diabetes in wild type mice. To test our hypothesis diabetes has been induced in Balb/c male mice by multiple low dose Streptozotocin injection; and a group of mice was contemporaneously injected with T3. After 48 h mice were tested for glucose tolerance test, insulin serum levels and then sacrified. Whole pancreata were utilized for morphological and biochemical analyses, while protein extracts and RNA were utilized for expression analyses of specific molecules. The results showed that islets from T3 treated mice were comparable to age- and sex-matched control, untreated mice in number, shape, dimension, consistency, ultrastructure, insulin and glucagon levels, Tunel positivity and caspases activation, while all the cited parameters and molecules were altered by STZ alone. The T3-induced pro survival effect was associated with a strong increase in phosphorylated Akt. Moreover, T3 administration prevented the STZ-dependent alterations in glucose blood level, both during fasting and after glucose challenge, as well as in insulin serum level. In conclusion we demonstrated that T3 could act as a protective factor against STZ induced diabetes

    Design, Fabrication, and Experimental Validation of Microfluidic Devices for the Investigation of Pore-Scale Phenomena in Underground Gas Storage Systems

    Get PDF
    The understanding of multiphase flow phenomena occurring in porous media at the pore scale is fundamental in a significant number of fields, from life science to geo and environmental engineering. However, because of the optical opacity and the geometrical complexity of natural porous media, detailed visual characterization is not possible or is limited and requires powerful and expensive imaging techniques. As a consequence, the understanding of micro-scale behavior is based on the interpretation of macro-scale parameters and indirect measurements. Microfluidic devices are transparent and synthetic tools that reproduce the porous network on a 2D plane, enabling the direct visualization of the fluid dynamics. Moreover, microfluidic patterns (also called micromodels) can be specifically designed according to research interests by tuning their geometrical features and surface properties. In this work we design, fabricate and test two different micromodels for the visualization and analysis of the gas-brine fluid flow, occurring during gas injection and withdrawal in underground storage systems. In particular, we compare two different designs: a regular grid and a real rock-like pattern reconstructed from a thin section of a sample of Hostun rock. We characterize the two media in terms of porosity, tortuosity and pore size distribution using the A* algorithm and CFD simulation. We fabricate PDMS-glass devices via soft lithography, and we perform preliminary air-water displacement tests at different capillary numbers to observe the impact of the design on the fluid dynamics. This preliminary work serves as a validation of design and fabrication procedures and opens the way to further investigations

    Percolating Reaction-Diffusion Waves (PERWAVES) — Sounding Rocket Combustion Experiments

    Get PDF
    Percolating reaction–diffusion waves in disordered random media are encountered in many branches of modern science, ranging from physics and biology to material science and combustion. Most disordered reaction–diffusion systems, however, have complex morphologies and reaction kinetics that complicate the study of the dynamics. Flames in suspensions of heterogeneously reacting metal-fuel particles is a rare example of a reaction–diffusion wave with a simple structure formed by point-like heat sources having well-defined ignition temperature thresholds and combustion times. Particle sedimentation and natural convection can be suppressed in the free-fall conditions of sounding rocket experiments, enabling the properties of percolating flames in suspensions to be observed, studied, and compared with emerging theoretical models. The current paper describes the design of the European Space Agency PERWAVES microgravity combustion apparatus, built by the Airbus Defense and Space team from Bremen in collaboration with the scientific research teams from McGill University and the Technical University of Eindhoven, and discusses the results of two sounding-rocket flight experiments. The apparatus allows multiple flame experiments in quartz glass tubes filled with uniform suspensions of 25-micron iron particles in oxygen/xenon gas mixtures. The experiments performed during the MAXUS-9 (April 2017) and TEXUS-56 (November 2019) sounding rocket flights have confirmed flame propagation in the discrete mode, which is a pre-requisite for percolating-flame behavior, and have allowed observation of the flame structure in the vicinity of the propagation threshold
    corecore