Random paths and current fluctuations in nonequilibrium statistical mechanics

An overview is given of recent advances in nonequilibrium statistical mechanics about the statistics of random paths and current fluctuations. Although statistics is carried out in space for equilibrium statistical mechanics, statistics is considered in time or spacetime for nonequilibrium systems. In this approach, relationships have been established between nonequilibrium properties such as the transport coefficients, the thermodynamic entropy production, or the affinities, and quantities characterizing the microscopic Hamiltonian dynamics and the chaos or fluctuations it may generate. This overview presents results for classical systems in the escape-rate formalism, stochastic processes, and open quantum systems

"Engaging with birth stories in pregnancy: a hermeneutic phenomenological study of women's experiences across two generations"

BACKGROUND: The birth story has been widely understood as a crucial source of knowledge about childbirth. What has not been reported is the effect that birth stories may have on primigravid women's understandings of birth. Findings are presented from a qualitative study exploring how two generations of women came to understand birth in the milieu of other's stories. The prior assumption was that birth stories must surely have a positive or negative influence on listeners, steering them towards either medical or midwifery-led models of care. METHODS: A Heideggerian hermeneutic phenomenological approach was used. Twenty UK participants were purposively selected and interviewed. Findings from the initial sample of 10 women who were pregnant in 2012 indicated that virtual media was a primary source of birth stories. This led to recruitment of a second sample of 10 women who gave birth in the 1970s-1980s, to determine whether they were more able to translate information into knowledge via stories told through personal contact and not through virtual technologies RESULTS: Findings revealed the experience of 'being-in-the-world' of birth and of stories in that world. From a Heideggerian perspective, the birth story was constructed through 'idle talk' (the taken for granted assumptions of things, which come into being through language). Both oral stories and those told through technology were described as the 'modern birth story'. The first theme 'Stories are difficult like that', examines the birth story as problematic and considers how stories shape meaning. The second 'It's a generational thing', considers how women from two generations came to understand what their experience might be. The third 'Birth in the twilight of certainty,' examines women's experience of Being in a system of birth as constructed, portrayed and sustained in the stories being shared. CONCLUSIONS: The women pregnant in 2012 framed their expectations in the language of choice, whilst the women who birthed in the 1970s-1980s framed their experience in the language of safety. For both, however, the world of birth was the same; saturated with, and only legitimised by the birth of a healthy baby. Rather than creating meaningful understanding, the 'idle talk' of birth made both cohorts fearful of leaving the relative comfort of the 'system', and of claiming an alternative birth

4,4’-dimethylaminorex (‘4,4’-DMAR’; ‘Serotoni’) misuse; a web-based study

This is the peer reviewed version of the following article: Loi B, Zloh M, De Luca MA, Pintori N, Corkery J, Schifano F. 4,4′-Dimethylaminorex (“4,4′-DMAR”; “Serotoni”) misuse: A Web-based study. Hum Psychopharmacol Clin Exp. 2017;32:e2575, which has been published in final form at https://doi.org/10.1002/hup.2575. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Copyright © 2017 John Wiley & Sons, Ltd.Background: 4,4′-DMAR (4,4’-dimethylaminorex; ‘Serotoni’) is a potent stimulant drug which has recently been associated with a number of fatalities in Europe. Over the last few years, online communities have emerged as important resources for disseminating levels of technical knowledge on novel psychoactive substances/NPS. Objective: Analysing the information provided by the fora communities on 4,4’-DMAR use, additionally critical reviewing the available evidence-based literature on this topic. Methods: Different website drug fora were identified. A critical review of the existing evidence-based literature was undertaken. Individuation and analysis of qualitative data from the identified website fora were performed. Results: The combined search results identified six website fora from which a range of qualitative data on recurring themes was collected. These themes included: routes of administration and doses; desired effects; adverse effects; comparison with other drugs; association with other drugs; medications self administered to reverse 4,4’-DMAR action; overall impression; provision of harm reduction advice. Conclusions: Although being characterized by a number of methodological limitations, the social networks’ web monitoring approach (netnography) may be helpful to better understand some of the clinical and psychopharmacological issues pertaining to a range of NPS, including 4,4’-DMAR, for which only extremely little, if any, scientific knowledge is availablePeer reviewe

The Zeroth Law of Thermodynamics and Volume-Preserving Conservative Dynamics with Equilibrium Stochastic Damping

We propose a mathematical formulation of the zeroth law of thermodynamics and develop a stochastic dynamical theory, with a consistent irreversible thermodynamics, for systems possessing sustained conservative stationary current in phase space while in equilibrium with a heat bath. The theory generalizes underdamped mechanical equilibrium: $dx=gdt+\{-D\nabla\phi dt+\sqrt{2D}dB(t)\}$, with $\nabla\cdot g=0$ and $\{\cdots\}$ respectively representing phase-volume preserving dynamics and stochastic damping. The zeroth law implies stationary distribution $u^{ss}(x)=e^{-\phi(x)}$. We find an orthogonality $\nabla\phi\cdot g=0$ as a hallmark of the system. Stochastic thermodynamics based on time reversal $\big(t,\phi,g\big)\rightarrow\big(-t,\phi,-g\big)$ is formulated: entropy production $e_p^{\#}(t)=-dF(t)/dt$; generalized "heat" $h_d^{\#}(t)=-dU(t)/dt$, $U(t)=\int_{\mathbb{R}^n} \phi(x)u(x,t)dx$ being "internal energy", and "free energy" $F(t)=U(t)+\int_{\mathbb{R}^n} u(x,t)\ln u(x,t)dx$ never increases. Entropy follows $\frac{dS}{dt}=e_p^{\#}-h_d^{\#}$. Our formulation is shown to be consistent with an earlier theory of P. Ao. Its contradistinctions to other theories, potential-flux decomposition, stochastic Hamiltonian system with even and odd variables, Klein-Kramers equation, Freidlin-Wentzell's theory, and GENERIC, are discussed.Comment: 25 page

Intrapericardial Extralobar Pulmonary Sequestration Presenting as a Prenatal Intrathoracic Mass

An intrathoracic mass, which persisted during the remaining pregnancy, was first seen during routine ultrasound examination performed at 20 weeks gestation. After birth, the child was asymptomatic. Echocardiography showed the mass to be located intrapericardially. The mass was electively resected via sternotomy 3 weeks after the birth. Microscopic examination showed normal lung tissue surrounded by pleura corresponding to the diagnosis of extralobar pulmonary sequestration. To the authors’ knowledge, this is the earliest described detection of such a lesion. Furthermore, this article reports the unique finding of a feeding vessel from the right pulmonary artery

Isotropic soft-core potentials with two characteristic length scales and anomalous behaviour

Isotropic soft-core potentials with two characteristic length scales have been used since 40 years to describe systems with polymorphism. In the recent years intense research is showing that these potentials also display polyamorphism and several anomalies, including structural, diffusion and density anomaly. These anomalies occur in a hierarchy that resembles the anomalies of water. However, the absence of directional bonding in these isotropic potentials makes them different from water. Other systems, such as colloidal suspensions, protein solutions or liquid metals, can be well described by these family of potentials, opening the possibility of studying the mechanism generating the polyamorphism and anomalies in these complex liquids

Schwannoma in Head and Neck: Preoperative Imaging Study and Intracapsular Enucleation for Functional Nerve Preservation

PURPOSE: In treating schwannoma patients, it is critical to determine the origin of the tumor to preserve nerve function. We evaluated the validity of preoperative imaging studies in distinguishing the neurological origin of the schwannomas of the head and neck, and the efficacy of intracapsular enucleation in preserving nerve function. MATERIALS AND METHODS: In 7 cases of schwannomas in the head and neck region, we predicted whether the tumor originated from the vagus nerve or the cervical sympathetic chain through imaging studies including computed tomography (CT) and magnetic resonance imaging (MRI). All patients were performed intracapsular enucleation, and the function of the vagus nerve and the sympathetic nerve was evaluated preoperatively and postoperatively. RESULTS: Preoperative imaging studies showed 6 cases where the tumor was located between the carotid artery and the internal jugular vein, and 1 case where the tumor was located posteriorly, displacing the carotid artery and the internal jugular vein anteriorly. At the time of operation, we confirmed schwannoma originating from the vagus nerve on the first 6 cases, and schwannoma originating from the sympathetic nervous system on the last case. All patients went through successful intracapsular enucleation, and of the seven schwannoma cases, 6 patients maintained normal postoperative neurological function (85.7%). CONCLUSION: Preoperative imaging studies offer valuable information regarding the location and origination of the tumor, and intracapsular enucleation helped us to preserve the nerve function.ope

Probing Ion-Ion and Electron-Ion Correlations in Liquid Metals within the Quantum Hypernetted Chain Approximation

We use the Quantum Hypernetted Chain Approximation (QHNC) to calculate the ion-ion and electron-ion correlations for liquid metallic Li, Be, Na, Mg, Al, K, Ca, and Ga. We discuss trends in electron-ion structure factors and radial distribution functions, and also calculate the free-atom and metallic-atom form-factors, focusing on how bonding effects affect the interpretation of X-ray scattering experiments, especially experimental measurements of the ion-ion structure factor in the liquid metallic phase.Comment: RevTeX, 19 pages, 7 figure

Diffusive and directional intracellular dynamics measured by field-based dynamic light scattering

Quantitative measurement of diffusive and directional processes of intracellular structures is not only critical in understanding cell mechanics and functions, but also has many applications, such as investigation of cellular responses to therapeutic agents. We introduce a label-free optical technique that allows non-perturbative characterization of localized intracellular dynamics. The method combines a field-based dynamic light scattering analysis with a confocal interferometric microscope to provide a statistical measure of the diffusive and directional motion of scattering structures inside a microscopic probe volume. To demonstrate the potential of this technique, we examined the localized intracellular dynamics in human epithelial ovarian cancer cells. We observed the distinctive temporal regimes of intracellular dynamics, which transitions from random to directional processes on a timescale of ∼0.01 sec. In addition, we observed disrupted directional processes on the timescale of 1∼5 sec by the application of a microtubule polymerization inhibitor, Colchicine, and ATP depletion. © 2010 Optical Society of America

Diagnosis and Management of Congenital Coronary Arteriovenous Fistula in the Pediatric Patients Presenting Congestive Heart Failure and Myocardial Ischemia

Purpose: Four pediatric patients with congenital coronary arteriovenous fistula (CAVF) were reported to remind pediatric practitioners and cardiologists of its diagnosis and management. Materials and Methods: Four pediatric patients with congenital CAVF from June 1999 to November 2007 were include in this retrospective study. Study modalities included reviews of patients' profiles of clinical features, chest radiograph, Doppler echocardiography, cardiac catheterization with angiography, myocardial perfusion scan, and computed tomography. Results: All 4 patients were symptomatic. The clinical symptoms and signs were feeding problem, continuous murmur, tachycardia, tachypnea, cardiomegaly, and exertional chest pain. Myocardial enzyme was elevated in 1 patient. Echocardiography showed dilatation of the coronary artery in all 4 patients, and traced down its origin in 3 and drainage in 4. The Fistulas originated from the right coronary artery in 2 patients and left coronary artery in 2, and were drained into the right ventricle in 2, right atrium in 1, and pulmonary artery in 1. Single left coronary artery was found in I patient. The pulmonary-to-systemic blood flow ratios ranged from 1.2 to 2.5. Transcatheter coil occlusion was successfully performed in 4 patients through a coaxial delivery system. The symptoms and signs of congestive heart failure and myocardial ischemia disappeared after the procedure, Conclusion: Diagnosis of congenital CAVF could be achieved by appreciation or continuous murmur over area unusual for the ductus, and by scrupulous examination of echocardiography as well as angiography of the coronary artery through which coaxial transcatheter coil occlusion could be performed successfully