Slow dynamics, aging, and glassy rheology in soft and living matter

We explore the origins of slow dynamics, aging and glassy rheology in soft and living matter. Non-diffusive slow dynamics and aging in materials characterised by crowding of the constituents can be explained in terms of structural rearrangement or remodelling events that occur within the jammed state. In this context, we introduce the jamming phase diagram proposed by Liu and Nagel to understand the ergodic-nonergodic transition in these systems, and discuss recent theoretical attempts to explain the unusual, faster-than-exponential dynamical structure factors observed in jammed soft materials. We next focus on the anomalous rheology (flow and deformation behaviour) ubiquitous in soft matter characterised by metastability and structural disorder, and refer to the Soft Glassy Rheology (SGR) model that quantifies the mechanical response of these systems and predicts aging under suitable conditions. As part of a survey of experimental work related to these issues, we present x-ray photon correlation spectroscopy (XPCS) results of the aging of laponite clay suspensions following rejuvenation. We conclude by exploring the scientific literature for recent theoretical advances in the understanding of these models and for experimental investigations aimed at testing their predictions.Comment: 22 pages, 5 postscript figures; invited review aricle, to appear in special issue on soft matter in Solid State Communication

Superconductivity above the lowest Earth temperature in pressurized sulfur hydride

A recent experiment has shown a macroscopic quantum coherent condensate at 203 K, about 19 degrees above the coldest temperature recorded on the Earth, 184 K, in pressurized sulfur hydride. This discovery is relevant not only in material science and condensed matter but also in other fields ranging from quantum computing to quantum physics of living matter. It has given the start to a gold rush looking for other macroscopic quantum coherent condensates in hydrides at the temperature range of living matter 200<Tc<400K. We present here a review of the experimental results and the theoretical works and we discuss the Fermiology of H3S focusing on Lifshitz transitions as a function of pressure. We discuss the possible role of the shape resonance near a neck disrupting Lifshitz transition, in the Bianconi-Perali Valletta (BPV) theory, for rising the critical temperature in a multigap superconductor, as the Feshbach resonance rises the critical temperature in Fermionic ultracold gases.Comment: 7 pages, 10 figures, Review Paper, Perspective for Europhysics Letter

Improved methods for counting bacteria in physiological fluids

Bacterial population detection is based on detection of adenosine triphosphate (ATP), chemical present in all living matter. Amount of ATP in sample, after chemically removing all nonbacterial ATP, is directly related to bacterial population. Sensitivity is improved by concentration step; specificity is improved by lowering pH of solution

Patenting Living Matter in the European Community: Diriment of the Draft Directive

This article attempts to disentangle the mire of European patent authority and provide some picture of how the ultimate resolution of the proposed EC Directive will appear. Part I contains introductory and background materials on the biotech industry and the importance of patent protection to the future proliferation of technological innovation. Part I exposes current issues in the scientific and political realms of biotech patent law as well as the standard justifications for recognizing inventors rights, considerations that are presently shaping the debate in Europe. Part II attempts to ground the reader in the fundamentals of biotechnology patent laws as developed in the United States in order to provide a basic conceptual foundation for comparing and evaluating the bodies of European law. This section begins by introducing the basic statutory terminology before turning to a discussion of the landmark United States Supreme Court opinion in Diamond v. Chakrabarty, where the Court held that genetically altered living matter may be patented.8 The remainder of the section traces the legal developments spawned by the Chakrabarty decision. Part III begins with an introduction of the various bodies purporting to govern patent rights in Europe and attempts to resolve the supremacy issues among them. Attention then shifts to the proposed Council Directive on biotech patents: the procedures for its adoption, the political forces shaping the debate of life patents in Europe, and the important proposals for amending the original draft. Finally, this article will speculate on the ultimate resolution of the Draft Directive as a united system of patent laws for the European Community Member States