On the Fluctuation Relation for Nose-Hoover Boundary Thermostated Systems

We discuss the transient and steady state fluctuation relation for a mechanical system in contact with two deterministic thermostats at different temperatures. The system is a modified Lorentz gas in which the fixed scatterers exchange energy with the gas of particles, and the thermostats are modelled by two Nos\'e-Hoover thermostats applied at the boundaries of the system. The transient fluctuation relation, which holds only for a precise choice of the initial ensemble, is verified at all times, as expected. Times longer than the mesoscopic scale, needed for local equilibrium to be settled, are required if a different initial ensemble is considered. This shows how the transient fluctuation relation asymptotically leads to the steady state relation when, as explicitly checked in our systems, the condition found in [D.J. Searles, {\em et al.}, J. Stat. Phys. 128, 1337 (2007)], for the validity of the steady state fluctuation relation, is verified. For the steady state fluctuations of the phase space contraction rate \zL and of the dissipation function \zW, a similar relaxation regime at shorter averaging times is found. The quantity \zW satisfies with good accuracy the fluctuation relation for times larger than the mesoscopic time scale; the quantity \zL appears to begin a monotonic convergence after such times. This is consistent with the fact that \zW and \zL differ by a total time derivative, and that the tails of the probability distribution function of \zL are Gaussian.Comment: Major revision. Fig.10 was added. Version to appear in Journal of Statistical Physic

158µJ pulses from a single transverse mode, large mode-area EDFA

We report the amplification of 10pJ-100pJ, semiconductor diode pulses up to an energy of 158µJ and peak powers >100kW in a multi-stage fibre amplifier chain based on a single-mode, large mode-area erbium doped amplifier design. These results represent the highest single-mode pulse energy ever extracted from any doped fibre system

Ferenc Kozár – A dedicated and prolific worker on scale insects

At the XII Meeting of the International Symposium on Scale Insect Studies, delegates and coccidologists worldwide congratulate Dr Ferenc Kozár for his work on scale insects during over 40 years of concentrated study. Ferenc is well known for his contributions to economic and taxonomic work on scale insects. He entered the Agricultural University in Budapest, Hungary, in 1962, and then the University of Leningrad (now St Petersburg) and returned to Hungary where he has been employed as Research Scientist and then Head of the Department of Zoology of the Hungarian Academy of Sciences in Budapest until 1990. He then became Research Consultant, a position he has held since. His list of publications includes nine books and about 220 papers in scientific journals. He has described 13 new family-group names, 32 new genera, and about 175 new species. Much of this work has been done since 1990. We expect a steady flow of publications in the future

Ostracods from freshwater and brackish environments of the Carboniferous of the Midland Valley of Scotland : the early colonization of terrestrial water bodies

The Mississippian Strathclyde Group of the Midland Valley of Scotland yields some of the earliest non-marine ostracods. The succession records shallow marine, deltaic, estuarine, lagoonal, lacustrine, fluvial and swamp environments representing a series of staging-posts between fully marine and limnetic settings. Macrofossils and ostracods are assigned to marine, marginal marine, brackish and freshwater environments based on their faunal assemblage patterns. Key brackish to freshwater ostracods are Geisina arcuata, Paraparchites circularis n. sp., Shemonaella ornata n. sp. and Silenites sp. A, associated with the bivalves Anthraconaia, Carbonicola, Cardiopteridium, Curvirimula, Naiadites, the microconchid ‘Spirorbis’, Spinicaudata and fish. Many Platycopina and Paraparchiticopina ostracods are interpreted as euryhaline, which corresponds with their occurrence in marine to coastal plain water bodies, and supports the ‘estuary effect’ hypothesis of non-marine colonization. The success of non-marine colonization by ostracods was dependent on the intrinsic adaptations of ostracod species to lower salinities, such as new reproductive strategies and the timing of extrinsic mechanisms to drive non-marine colonization, such as sea-level change. The genus Carbonita is the oldest and most common freshwater ostracod, and went on to dominate freshwater environments in the Late Palaeozoic

The Steady State Fluctuation Relation for the Dissipation Function

We give a proof of transient fluctuation relations for the entropy production (dissipation function) in nonequilibrium systems, which is valid for most time reversible dynamics. We then consider the conditions under which a transient fluctuation relation yields a steady state fluctuation relation for driven nonequilibrium systems whose transients relax, producing a unique nonequilibrium steady state. Although the necessary and sufficient conditions for the production of a unique nonequilibrium steady state are unknown, if such a steady state exists, the generation of the steady state fluctuation relation from the transient relation is shown to be very general. It is essentially a consequence of time reversibility and of a form of decay of correlations in the dissipation, which is needed also for, e.g., the existence of transport coefficients. Because of this generality the resulting steady state fluctuation relation has the same degree of robustness as do equilibrium thermodynamic equalities. The steady state fluctuation relation for the dissipation stands in contrast with the one for the phase space compression factor, whose convergence is problematic, for systems close to equilibrium. We examine some model dynamics that have been considered previously, and show how they are described in the context of this work.Comment: 30 pages, 1 figur

FLIC-Overlap Fermions and Topology

APE smearing the links in the irrelevant operators of clover fermions (Fat-Link Irrelevant Clover (FLIC) fermions) provides significant improvement in the condition number of the Hermitian-Dirac operator and gives rise to a factor of two savings in computing the overlap operator. This report investigates the effects of using a highly-improved definition of the lattice field-strength tensor F_mu_nu in the fermion action, made possible through the use of APE-smeared fat links in the construction of the irrelevant operators. Spurious double-zero crossings in the spectral flow of the Hermitian-Wilson Dirac operator associated with lattice artifacts at the scale of the lattice spacing are removed with FLIC fermions composed with an O(a^4)-improved lattice field strength tensor. Hence, FLIC-Overlap fermions provide an additional benefit to the overlap formalism: a correct realization of topology in the fermion sector on the lattice.Comment: Lattice2002(chiral

A systematic review of the nutritional consequences of esophagectomy

Background & aims As improved outcomes after esophagectomy have been observed over the last two decades, the focus on care has shifted to survivorship and quality of life. The aim of this review was to determine changes in nutrition after esophagectomy and to assess the evidence for extended nutrition support. Methods A search strategy was developed to identify primary research reporting change in nutritional status a minimum of one month after esophagectomy. Results Changes in nutritional parameters reported by 18 studies indicated a weight loss of 5–12% at six months postoperatively. More than half of patients lost >10% of body weight at 12 months. One study reported a persistent weight loss of 14% from baseline three years after surgery. Three studies reporting on longer term follow up noted that 27%–95% of patients failed to regain their baseline weight. Changes in dietary intake (three studies) indicated inadequate energy and protein intake up to three years after surgery. Global quality of life scores reported in one study correlated with better weight preservation. There were a high frequency of gastrointestinal symptoms reported in six studies, most notably in the first year after surgery, but persisting up to 19 years. Extended enteral nutrition on a selective basis has been reported in several studies. Conclusions Nutritional status is compromised in the months/years following oesophagectomy and may never return to baseline levels. The causes/consequences of weight loss/impaired nutritional intake require further investigation. The role of extended nutritional support in this population remains unclear

A field based method for pre-concentration of micro organics using solid phase extraction

British Geological Survey (BGS) have been researching micro-organic pollutants for many years in the UK (Gooddy et al 2004, Stuart et al 2012, White et al 2016) and overseas (Sorensen et al 2015). A hindrance to the research, especially overseas, has been the need to transport large volumes of water back to the laboratory and the worry of degradation during transportation prior to LCMS or GCMS analysis. The first step in the LCMS analytical procedure is the solid phase extraction of the micro-organic contaminants onto a small cartridge. This report details the field trial where by BGS, working in conjunction with NLS, carried out the pre-concentration step of sample processing in the field. NLS provided pre-conditioned sorbent Oasis® HLB cartridges supplied in sealed Corning centristar centrifuge tubes. Water samples were run through the cartridges by the field team using a small peristaltic pump prior to sending to NLS for semi-quantative broad screen LCMS analysis. To check the repeatability and the stability of this method the sorbed samples were analysed in duplicate and replicate analysis was carried out over set periods after storage for up to a month. The results from the duplicate replicates are compared to results from the original water sample analysed immediately after sampling. Laboratory and field equipment blanks were included in the trial to check for any contamination introduced by the sampling method and extraction process. Preliminary results demonstrate that for a large range of compounds, and different types of matrices, this method was able to preserve samples for up to a month. Once the procedure had been validated, it was used to investigate the occurrence of micro-pollutants in a rural groundwater, estuarine waters and a range of surface waters receiving treated sewerage outflows. The work was funded under the BGS Development Capabilities programme, and was also supported by the BGS Groundwater Science programme under the Groundwater Protection team. Analytical aspects of this work was undertaken in collaboration with Wayne Civil based at Star Cross National Science Laboratory (NLS)

Experimental Assessment of Proximal Stent-graft (InterVascularTM) Fixation in Human Cadaveric Infrarenal Aortas

AbstractObjectivesthis paper investigates the radial deformation load of an aortic endoluminal prosthesis and determines the longitudinal load required to cause migration in a human cadaveric aorta of the endoprosthesis.Design and methodsthe endovascular prosthesis under investigation was a 24 mm diameter, nitinol, self-expanding aortoaortic device (InterVascular, Clearwater, Florida, U.S.A.). Initially, a motorised digital force gauge developed an incremental load which was applied to the ends of five stent-grafts, to a maximum of 10 mm (42%) compression. Secondly, using a simple bench model, each end of four stent-grafts were deployed into 10 cadaveric experimental aneurysm necks and a longitudinal load applied to effect distraction.Resultsincreasing load produced increasing percentage deformation of the stent-grafts. The mean longitudinal distraction load for an aneurysm neck of 20 mm was 409 g (200–480 g), for 15 mm was 277 g (130–410 g) and for 10 mm was 218 g (130–340 g). The aneurysm diameter and aortic calcification hadpvalues of 0.002 and 0.047, respectively, while thepvalue for aneurysm neck length was less than 0.00001.Conclusionsthese results suggest that there is a theoretical advantage of oversizing an aortic prosthesis and that sufficient anchorage is achieved in an aortic neck of 10 mm to prevent migration when fully deployed