Mammalian hibernation: lessons for organ preparation?

The adaptations to low environmental temperatures exhibited in mammalian hibernation are many and varied, and involve molecular and cellular mechanisms as well as the systematic physiology of the whole organism. Natural torpidity is characterised by a profound reduction in body temperature and other functions lasting from a few hours to several weeks. Controlled reduction of heart rate, respiration and oxygen consumption is followed by the fall in body temperature. However, thermoregulation persists such that a decrease in ambient temperature below dangerous levels typically triggers arousal, and shivering and non-shivering thermogenesis from brown fat provide the heat to restore body temperature to normal levels. Many of the cellular mechanisms for survival are similar to those brought into play during medium-term storage of organs destined for transplantation. For example maintenance of ionic regulation and membrane fluxes is fundamental to cell survival and function at low body temperatures. Differences between hibernating and non-hibernating species are marked by differences in Na+/K+ transport and Ca++pumps. These in turn are probably associated with alterations in the lipoproteins of the plasma membrane and inner mitochondrial membrane. We have accordingly conducted a series of pilot studies in captured Richardson's ground squirrels kept in laboratory conditions as a model for hypothermic organ preservation. Tissue function was compared during the summer (non-hibernating season) with that in the winter when the animals could be: (i) in deep hibernation in a cold chamber at 4 degree C; (ii) maintained in an ambient temperature of 4 degree C but active and awake; or (iii) active at an ambient temperature of 22 degree C. The studies involved: whole animal monitoring of standard physiological parameters; whole organ (kidney) storage and transplantation for viability assessment; storage and functional assessment on an ex vivo test circuit with capacity for perfusion at normothermic and hypothermic temperatures; measurement of thyroid function; measurements of total nucleotides (ATP, ADP and AMP)and ratios by standard techniques after freeze-clamping of organs; similar nucleotide and pH measurements using31P-NMR as a non-invasive whole animal technique; and measurement of O2 uptake and gluconeogenesis using isolated renal tubules and isolated hepatocytes. Marked differences in cold tolerance were demonstrated between organs taken from hibernating versus non-hibernating individuals. In particular kidneys transplanted from animals in deep hibernation were capable of withstanding up to 72 hours of cold storage as compared with up to 24 hours in non-hibernating squirrels or in comparable sized rats. Adaptations which might provide valuable clues in our attempts to better preserve human organs for transplantation are explored in some depth in this report.     

Sturm-Schrödinger equations: Formula for metric

Sturm-Schrödinger equations Hψ = EWψ with H ≠ H ^? and W≠ = W ^? ≠ = I are considered, with a weak point of the theory lying in the purely numerical matrix-inversion form of the double-series definition of the necessary metric operator Θ in the physical Hilbert space of states [M Znojil, J. Phys. A: Math. Theor. 41, 215304 (2008]. This shortcoming is removed here via an amended, single-series definition of Θ.     

Data processing for the sandwiched Rényi divergence: a condition for equality

The \(\alpha \)-sandwiched Rényi divergence satisfies the data processing inequality, i.e. monotonicity under quantum operations, for \(\alpha \ge 1/2\). In this article, we derive a necessary and sufficient algebraic condition for equality in the data processing inequality for the \(\alpha \)-sandwiched Rényi divergence for all \(\alpha \ge 1/2\). For the range \(\alpha \in [1/2,1)\), our result provides the only condition for equality obtained thus far. To prove our result, we first consider the special case of partial trace and derive a condition for equality based on the original proof of the data processing inequality by Frank and Lieb (J Math Phys 54(12):122201, 2013) using a strict convexity/concavity argument. We then generalize to arbitrary quantum operations via the Stinespring Representation Theorem. As applications of our condition for equality in the data processing inequality, we deduce conditions for equality in various entropic inequalities. We formulate a Rényi version of the Araki–Lieb inequality and analyze the case of equality, generalizing a result by Carlen and Lieb (Lett Math Phys 101(1):1–11, 2012) about equality in the original Araki–Lieb inequality. Furthermore, we prove a general lower bound on a Rényi version of the entanglement of formation and observe that it is attained by states saturating the Rényi version of the Araki–Lieb inequality. Finally, we prove that the known upper bound on the entanglement fidelity in terms of the usual fidelity is saturated only by pure states.     

Inverstigation of Self-Starting for Self-Mode-Locked Ti:Sapphire Laser

ＩｎｖｅｒｓｔｉｇａｔｉｏｎｏｆＳｅｌｆ－ＳｔａｒｔｉｎｇｆｏｒＳｅｌｆ－Ｍｏｄｅ－ＬｏｃｋｅｄＴｉ：ＳａｐｐｈｉｒｅＬａｓｅｒＩｎｖｅｒｓｔｉｇａｔｉｏｎｏｆＳｅｌｆ－ＳｔａｒｔｉｎｇｆｏｒＳｅｌｆ－Ｍｏｄｅ－ＬｏｃｋｅｄＴｉ：ＳａｐｐｈｉｒｅＬａ...     

β relaxation theory for simple systems: some addenda

The evolution of the tagged particle probability density for a hard sphere system is evaluated within the -relaxation window. Relaxation curves obtained by molecular dynamics studies by Barrat, Hansen and Roux for a binary mixture are analyzed quantitatively with -relaxation scaling formulae. The dynamical light scattering data obtained by Pusey and van Megen for colloidal suspensions are described by the combined - and -relaxation scaling results. The range of validity of asymptotic expressions near a glass transition singularity is discussed for the Debye-Waller factor as a function of packing fraction. The applied theoretical formulae are those of the mode coupling theory for the liquid to glass transition.     

Lévy walks for turbulence: A numerical study

We present a numerical study of enhanced diffusion, for which the mean-squared displacement follows asymptotically r ²(t) t , > 1. We simulate continuous time random walks with waiting-time distributions which couple the spatial and temporal parameters; this gives rise to Lévy-walks. Our results confirm the theoretically predicted long-time behavior and demonstrate its temporal regime of validity. Furthermore, the simulations document the appearance of (parameter-dependent) transitions between regular and enhanced diffusion regimes.     

Letter: Embedding Diagrams for the Reissner-Nordström Spacetime

We consider embedding diagrams for the Reissner-Nordström spacetime. We embed the r–t and r– 2-surfaces into (2+1)/3-Euclidean space and discuss the relation between the diagrams and the corresponding curvature scalar of the 2-metrics.     

Anderson localization for the almost Mathieu equation: II. Point spectrum for λ>2

We prove that for any >2 and a.e. , the pure point spectrum of the almost Mathieu operator (H()) _n = _n-1 + _n+1 + cos(2( +n)) _n contains the essential closure of the spectrum. Corresponding eigenfunctions decay exponentially. The singular continuous component, if it exists, is concentrated on a set of zero measure which is nowhere dense in .     

Energy reduction:a technique for seed-injection locking of single-axial-mode Q-switched Nd:YAG laser

A new technique for seed-injection locking of single-axial-mode (SAM) Q-switched Nd:YAG laser is re- ported.The technique called energy reduction (ER) is utilized when SAM operation is locked to design its feedback scheme.This method ensures long-term 100% seed-injection locking performance and the pulsed SAM output energy can reach as high as 200 mJ.Both temporal and spatial interferometric experiments have been executed to confirm the SAM oscillation.     

Stars from birth to death: Laboratories for exotic nuclei?

Recent developments in theoretical model calculations for the synthesis of the chemical elements in stars are reviewed. Special emphasis is put on a discussion of various astrophysical sites, including the Sun and core collapse and thermonuclear supernovae. Results of numerical simulations are presented and discussed, together with new results concerning solar-system abundances as well as abundances observed in very metal-poor stars, in the context of searches for constraints on the still rather uncertain nuclear-physics data and astrophysical models. Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002 RID="a" ID="a"e-mail: wfh@mpa-garching.mpg.de     

“Synthetic metals”: a novel role for organic polymers

Since the initial discovery in 1977, that polyacetylene (CH)_x, now commonly known as the prototype conducting polymer, could be p- or n-doped either chemically or electronically to the metallic state, the development of the field conducting polymers, “synthetic metals”, has continued to accelerate at an unexpectedly rapid rate and a variety of other conducting polymers and their derivatives have been discovered. Potential new science/technology has been developed by combining the now well established field of electronic polymers (intrinsically conducting polymers – “synthetic metals”, when doped) with the emerging field of nanoscience (one dimension <100 nm). A simple and inexpensive method is described for producing conducting patterns of electronic polymers on plastic and paper from computer-designed patterns. This method, “Line Patterning”, does not involve printing of the conducting polymers. The difference in hydrophobicity/hydrophilicity between a substrate and a line of regular toner printed on it by a non-modified, standard ofiice laser printer results in conducting polymer areas separated by insulating toner lines.     

Quantum α-entropy inequalities: independent condition for local realism?

Quantum α-entropy inequalities equivalent to Bell's inequality for pure states are considered in the context of the local hidden variable (LHV) model and compared with Bell's inequalities. For α = 1,2 they are shown to be satisfied by convex combinations of product states and Werner's mixtures admitting the model. The 2-entropy inequality is proven to be stronger than Bell's inequality in the case. In the latter, the α-entropy inequalities taken as a joint condition exclude teleportation admitted in spite of the existence of the LHV model for the Werner-Popescu states.     

Laser-induced damage of high reflectors for Ti:sapphire laser system

A broadband(～176nm,R>98%,λo=800nm)and high laser-induced damage threshold(LIDT= 2.4J/cm~2)TiO_2/HfO_2/SiO_2 high reflector(HR)for Ti:sapphire chirped-pulse amplification(CPA)laser system is fabricated by the electron beam evaporation.The refractive index and extinction coefficient of TiO_2 and HfOu films are calculated from single-layer films' transmittance spectra.The properties of HR are mainly determined by the high refractive index material.The high refractive index leads to wide bandwidth.A low extinction coefficient indicates low absorption and high LIDT.The possible damage mechanism of HR is discussed.