Experiment K-6-09. Morphological and biochemical investigation of microgravity-induced nerve and muscle breakdown. Part 1: Investigation of nerve and muscle breakdown during spaceflight; Part 2: Biochemical analysis of EDL and PLT muscles

The present findings on rat hindlimb muscles suggest that skeletal muscle weakness induced by prolonged spaceflight can result from a combination of muscle fiber atrophy, muscle fiber segmental necrosis, degeneration of motor nerve terminals and destruction of microcirculatory vessels. Damage was confined to the red adductor longus (AL) and soleus muscles. The midbelly region of the AL muscle had more segmental necrosis and edema than the ends. Macrophages and neutrophils were the major mononucleated cells infiltrating and phagocytosing the cellular debris. Toluidine blue-positive mast cells were significantly decreased in Flight AL muscles compared to controls; this indicated that degranulation of mast cells contributed to tissue edema. Increased ubiquitination of disrupted myofibrils may have promoted myofilament degradation. Overall, mitochondria content and SDH activity were normal, except for a decrease in the subsarcolemmal region. The myofibrillar ATPase activity shifted toward the fast type in the Flight AL muscles. Some of the pathological changes may have occurred or been exacerbated during the 2 day postflight period of readaptation to terrestrial gravity. While simple atrophy should be reversible by exercise, restoration of pathological changes depends upon complex processes of regeneration by stem cells. Initial signs of muscle and nerve fiber regeneration were detected. Even though regeneration proceeds on Earth, the space environment may inhibit repair and cause progressive irreversible deterioration during long term missions. Muscles obtained from Flight rats sacrificed immediately (within a few hours) after landing are needed to distinguish inflight changes from postflight readaptation

The structure of causal sets

More often than not, recently popular structuralist interpretations of physical theories leave the central concept of a structure insufficiently precisified. The incipient causal sets approach to quantum gravity offers a paradigmatic case of a physical theory predestined to be interpreted in structuralist terms. It is shown how employing structuralism lends itself to a natural interpretation of the physical meaning of causal sets theory. Conversely, the conceptually exceptionally clear case of causal sets is used as a foil to illustrate how a mathematically informed rigorous conceptualization of structure serves to identify structures in physical theories. Furthermore, a number of technical issues infesting structuralist interpretations of physical theories such as difficulties with grounding the identity of the places of highly symmetrical physical structures in their relational profile and what may resolve these difficulties can be vividly illustrated with causal sets.Comment: 19 pages, 4 figure

Self Running Droplet: Emergence of Regular Motion from Nonequilibrium Noise

Spontaneous motion of an oil droplet driven by chemical nonequilibricity is reported. It is shown that the droplet undergoes regular rhythmic motion under appropriately designed boundary conditions, whereas it exhibits random motion in an isotropic environment. This study is a novel manifestation on the direct energy transformation of chemical energy into regular spatial-motion under isothermal conditions. A simple mathematical equation including noise reproduces the essential feature of the transition from irregularity into periodic regular motion. Our results will inspire the theoretical study on the mechanism of molecular motors in living matter, working under significant influence of thermal fluctuation.Comment: 4 pages, 4 figure

Disrupted Maturation of the Microbiota and Metabolome among Extremely Preterm Infants with Postnatal Growth Failure

Growth failure during infancy is a major global problem that has adverse effects on long-term health and neurodevelopment. Preterm infants are disproportionately affected by growth failure and its effects. Herein we found that extremely preterm infants with postnatal growth failure have disrupted maturation of the intestinal microbiota, characterized by persistently low diversity, dominance of pathogenic bacteria within the Enterobacteriaceae family, and a paucity of strictly anaerobic taxa including Veillonella relative to infants with appropriate postnatal growth. Metabolomic profiling of infants with growth failure demonstrated elevated serum acylcarnitines, fatty acids, and other byproducts of lipolysis and fatty acid oxidation. Machine learning algorithms for normal maturation of the microbiota and metabolome among infants with appropriate growth revealed a pattern of delayed maturation of the microbiota and metabolome among infants with growth failure. Collectively, we identified novel microbial and metabolic features of growth failure in preterm infants and potentially modifiable targets for intervention

Continuous Equilibrium in Affine and Information-Based Capital Asset Pricing Models

We consider a class of generalized capital asset pricing models in continuous time with a finite number of agents and tradable securities. The securities may not be sufficient to span all sources of uncertainty. If the agents have exponential utility functions and the individual endowments are spanned by the securities, an equilibrium exists and the agents' optimal trading strategies are constant. Affine processes, and the theory of information-based asset pricing are used to model the endogenous asset price dynamics and the terminal payoff. The derived semi-explicit pricing formulae are applied to numerically analyze the impact of the agents' risk aversion on the implied volatility of simultaneously-traded European-style options.Comment: 24 pages, 4 figure

Lattice dynamics and structural stability of ordered Fe3Ni, Fe3Pd and Fe3Pt alloys

We investigate the binding surface along the Bain path and phonon dispersion relations for the cubic phase of the ferromagnetic binary alloys Fe3X (X = Ni, Pd, Pt) for L12 and DO22 ordered phases from first principles by means of density functional theory. The phonon dispersion relations exhibit a softening of the transverse acoustic mode at the M-point in the L12-phase in accordance with experiments for ordered Fe3Pt. This instability can be associated with a rotational movement of the Fe-atoms around the Ni-group element in the neighboring layers and is accompanied by an extensive reconstruction of the Fermi surface. In addition, we find an incomplete softening in [111] direction which is strongest for Fe3 Ni. We conclude that besides the valence electron density also the specific Fe-content and the masses of the alloying partners should be considered as parameters for the design of Fe-based functional magnetic materials.Comment: Revised version, accepted for publication in Physical Review

Black strings in asymptotically plane wave geometries

We present a class of black string spacetimes which asymptote to maximally symmetric plane wave geometries. Our construction will rely on a solution generating technique, the null Melvin twist, which deforms an asymptotically flat black string spacetime to an asymptotically plane wave black string spacetime while preserving the event horizon.Comment: 15 pages; references adde

Update of Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias (International Endohernia Society (IEHS)) : Part B

In 2014 the International Endohernia Society (IEHS) published the first international "Guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias". Guidelines reflect the currently best available evidence in diagnostics and therapy and give recommendations to help surgeons to standardize their techniques and to improve their results. However, science is a dynamic field which is continuously developing. Therefore, guidelines require regular updates to keep pace with the evolving literature. Methods For the development of the original guidelines all relevant literature published up to year 2012 was analyzed using the ranking of the Oxford Centre for Evidence-Based-Medicine. For the present update all of the previous authors were asked to evaluate the literature published during the recent years from 2012 to 2017 and revise their statements and recommendations given in the initial guidelines accordingly. In two Consensus Conferences (October 2017 Beijing, March 2018 Cologne) the updates were presented, discussed, and confirmed. To avoid redundancy, only new statements or recommendations are included in this paper. Therefore, for full understanding both of the guidelines, the original and the current, must be read. In addition, the new developments in repair of abdominal wall hernias like surgical techniques within the abdominal wall, release operations (transversus muscle release, component separation), Botox application, and robot-assisted repair methods were included. Results Due to an increase of the number of patients and further development of surgical techniques, repair of primary and secondary abdominal wall hernias attracts increasing interests of many surgeons. Whereas up to three decades ago hernia-related publications did not exceed 20 per year, currently this number is about 10-fold higher. Recent years are characterized by the advent of new techniques-minimal invasive techniques using robotics and laparoscopy, totally extraperitoneal repairs, novel myofascial release techniques for optimal closure of large defects, and Botox for relaxing the abdominal wall. Furthermore, a concomitant rectus diastasis was recognized as a significant risk factor for recurrence. Despite still insufficient evidence with respect to these new techniques it seemed to us necessary to include them in the update to stimulate surgeons to do research in these fields. Conclusion Guidelines are recommendations based on best available evidence intended to help the surgeon to improve the quality of his daily work. However, science is a continuously evolving process, and as such guidelines should be updated about every 3 years. For a comprehensive reference, however, it is suggested to read both the initially guidelines published in 2014 together with the update. Moreover, the presented update includes also techniques which were not known 3 years before

On the shopfloor: exploring the impact of teacher trade unions on school-based industrial relations

Teachers are highly unionised workers and their trade unions exert an important influence on the shaping and implementation of educational policy. Despite this importance there is relatively little analysis of the impact of teacher trade unions in educational management literature. Very little empirical research has sought to establish the impact of teacher unions at school level. In an era of devolved management and quasi-markets this omission is significant. New personnel issues continue to emerge at school level and this may well generate increased trade union activity at the workplace. This article explores the extent to which devolved management is drawing school-based union representation into a more prominent role. It argues that whilst there can be significant differences between individual schools, increased school autonomy is raising the profile of trade union activity in the workplace, and this needs to be better reflected in educational management research

Radiative association and inverse predissociation of oxygen atoms

The formation of \mbox{O}_2 by radiative association and by inverse predissociation of ground state oxygen atoms is studied using quantum-mechanical methods. Cross sections, emission spectra, and rate coefficients are presented and compared with prior experimental and theoretical results. At temperatures below 1000~K radiative association occurs by approach along the $1\,{}^3\Pi_u$ state of \mbox{O}_2 and above 1000~K inverse predissociation through the \mbox{B}\,{}^3\Sigma_u^- state is the dominant mechanism. This conclusion is supported by a quantitative comparison between the calculations and data obtained from hot oxygen plasma spectroscopy.Comment: submitted to Phys. Rev. A (Sept. 7., 1994), 19 pages, 4 figures, latex (revtex3.0 and epsf.sty