Soliton attenuation and emergent hydrodynamics in fragile matter

Disordered packings of soft grains are fragile mechanical systems that loose rigidity upon lowering the external pressure towards zero. At zero pressure, we find that any infinitesimal strain-impulse propagates initially as a non-linear solitary wave progressively attenuated by disorder. We demonstrate that the particle fluctuations generated by the solitary-wave decay, can be viewed as a granular analogue of temperature. Their presence is manifested by two emergent macroscopic properties absent in the unperturbed granular packing: a finite pressure that scales with the injected energy (akin to a granular temperature) and an anomalous viscosity that arises even when the microscopic mechanisms of energy dissipation are negligible. Consistent with the interpretation of this state as a fluid-like thermalized state, the shear modulus remains zero. Further, we follow in detail the attenuation of the initial solitary wave identifying two distinct regimes : an initial exponential decay, followed by a longer power law decay and suggest simple models to explain these two regimes.Comment: 8 pages, 3 Figure

Enhanced Resolution of Lossy Interferometry by Coherent Amplification of Single Photons

In the quantum sensing context most of the efforts to design novel quantum techniques of sensing have been constrained to idealized, noise-free scenarios, in which effects of environmental disturbances could be neglected. In this work, we propose to exploit optical parametric amplification to boost interferometry sensitivity in the presence of losses in a minimally invasive scenario. By performing the amplification process on the microscopic probe after the interaction with the sample, we can beat the losses detrimental effect on the phase measurement which affects the single-photon state after its interaction with the sample, and thus improve the achievable sensitivity.Comment: 4 + 3 pages, 3 + 5 figure

Quantum to classical transition via fuzzy measurements on high gain spontaneous parametric down-conversion

We consider the high gain spontaneous parametric down-conversion in a non collinear geometry as a paradigmatic scenario to investigate the quantum-to-classical transition by increasing the pump power, that is, the average number of generated photons. The possibility of observing quantum correlations in such macroscopic quantum system through dichotomic measurement will be analyzed by addressing two different measurement schemes, based on different dichotomization processes. More specifically, we will investigate the persistence of non-locality in an increasing size n/2-spin singlet state by studying the change in the correlations form as $n$ increases, both in the ideal case and in presence of losses. We observe a fast decrease in the amount of Bell's inequality violation for increasing system size. This theoretical analysis is supported by the experimental observation of macro-macro correlations with an average number of photons of about 10^3. Our results enlighten the practical extreme difficulty of observing non-locality by performing such a dichotomic fuzzy measurement.Comment: 15 pages, 18 figure

Solid friction between soft filaments

Any macroscopic deformation of a filamentous bundle is necessarily accompanied by local sliding and/or stretching of the constituent filaments. Yet the nature of the sliding friction between two aligned filaments interacting through multiple contacts remains largely unexplored. Here, by directly measuring the sliding forces between two bundled F-actin filaments, we show that these frictional forces are unexpectedly large, scale logarithmically with sliding velocity as in solid-like friction, and exhibit complex dependence on the filaments' overlap length. We also show that a reduction of the frictional force by orders of magnitude, associated with a transition from solid-like friction to Stokes' drag, can be induced by coating F-actin with polymeric brushes. Furthermore, we observe similar transitions in filamentous microtubules and bacterial flagella. Our findings demonstrate how altering a filament's elasticity, structure and interactions can be used to engineer interfilament friction and thus tune the properties of fibrous composite materials

General rules for bosonic bunching in multimode interferometers

We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure

Vulnerable personality and Takotsubo cardiomyopathy consequent to emotional stressful events: a clinical case report

Introduction: Although the onset of Takotsubo cardiomyopathy (TTC) can be triggered by an acute, intense emotional stress, the exact pathogenic mechanisms still remain undefined. Presentation: A 58-year-old female was sent by ambulance to the Emergency Department (ED) for chest pain and ST elevations on ECG. Her chest pain began 3 hours before on admission after a domestic argument. Transthoracic echocardiogram showed severe systolic dysfunction with an ejection fraction of 20%. Cardiac catheterization revealed no significant coronary artery disease. The left ventriculogram showed apical ballooning with hyperdynamic proximal segments. A diagnosis of Takotsubo Cardiomyophaty (TTC) was made according to the Mayo Clinic 2008 criteria. The patient evolved with improvement of her condition and, therefore, was discharged from the hospital. Follow-up echocardiogram seven days later showed normal LV size and function with ejection fraction (EF) of 43%. Paykel Life Stress Event Scale identified as emotional trigger a domestic argument occurred 3 hours before symptom onset. History showed a major life stress event, death of a loved one, six months before symptoms. The patient underwent psychological assessment after hospital discharge by Emotional Regulation Questionnaire and BDI showing high suppression/ low reappraisal profile and moderate depression. Conclusion: This case highlights the hypothesis of a possible link between cognitive emotional processing and vulnerability to Takotsubo syndrome

Impact of patent ductus arteriosus on non-invasive assessments of lung fluids in very preterm infants during the transitional period

This prospective observational study aimed to evaluate whether lung fluids, assessed by lung ultrasonography and transthoracic electrical bioimpedance (TEB), may be influenced by the presence of a haemodynamically significant patent ductus arteriosus (hsPDA) in very preterm infants during the transitional period. Infants < 32 weeks of gestational age (GA) admitted to the neonatal intensive care units of IRCCS AOU Bologna and Niguarda Metropolitan Hospital of Milan (Italy) underwent a daily assessment of a lung ultrasound score (LUS) and of a TEB-derived index of thoracic fluid contents (TFC) during the first 72 h after birth. Echocardiographic scans were simultaneously performed to evaluate the concomitant ductal status (hsPDA vs. restrictive or closed duct). The correlation between LUS, TFC, and the ductal status was tested using generalized estimating equations. Forty-six infants (median GA: 29 [interquartile range, IQR: 27-31] weeks; median birth weight: 1099 [IQR: 880-1406] g) were included. At each daily evaluation, the presence of a hsPDA was associated with significantly higher LUS and TFC compared with a restrictive or closed ductus (p < 0.01 for all comparisons). These results were confirmed significant even after adjustment for GA and for the ongoing modality of respiratory support.Conclusion: Even during the first 72 h of life, the presence of a hsPDA determines a significant increase in pulmonary fluids which can be non-invasively detected and monitored over time using lung ultrasonography and TEB

Internalized Transphobia, Resilience, and Mental Health: Applying the Psychological Mediation Framework to Italian Transgender Individuals

Transgender and gender nonconforming (TGNC) people are a highly-stigmatized population. For this reason, they might internalize society’s normative gender attitudes and develop negative mental health outcomes. As an extension of the minority stress model, the psychological mediation framework sheds light on psychological processes through which anti-transgender discrimination might affect mental health. Within this framework, the current study aimed at assessing in 149 TGNC Italian individuals the role of internalized transphobia as a mediator between anti-transgender discrimination and mental health, considering resilience as the individual-level coping mechanism buffering this relationship. The results suggest that both indicators of internalized transphobia (i.e., shame and alienation) mediate the relationship between anti-transgender discrimination and depression, while only alienation mediates the relationship between anti-transgender discrimination and anxiety. Furthermore, the results suggest that the indirect relation between anti-transgender discrimination and anxiety through alienation is conditional on low and moderate levels of resilience. Findings have important implications for clinical practice and psycho-social interventions to reduce stigma and stress caused by interpersonal and individual stigma