Horse portraiture: embracing breeding, rearing and training trotters, with their management in the stable and on the track, and preparation for races; including histories of the horse and horsemen.

Mode of access: Internet.

Assessing Fracture Connectivity using Stable and Clumped Isotope Geochemistry of Calcite Cements

Understanding flow path connectivity within a geothermal reservoir is a critical component for efficiently producing sustained flow rates of hot fluids from the subsurface. I present a new approach for characterizing subsurface fracture connectivity that combines petrographic and cold cathodoluminescence (CL) microscopy with stable isotope analysis (δ18O and δ13C) and clumped isotope (Δ47) thermometry of fracture-filling calcite cements from a geothermal reservoir in northern Nevada. Calcite cement samples were derived from both drill cuttings and core samples taken at various depths from wells within the geothermal field. CL microscopy of some fracture filling cements shows banding parallel to the fracture walls as well as brecciation, indicating that the cements are related to fracture opening and fault slip. Variations in trace element composition indicated by the luminescence patterns reflect variations in the composition and source of fluids moving through the fractures as they opened episodically. Calcite δ13C and δ18O results also show significant variation among the sampled cements, reflecting multiple generations of fluids and fracture connectivity. Clumped isotope analyses performed on a subset of the cements analyzed for conventional δ18O and δ13C mostly show calcite growth temperatures around 150°C—above the current ambient rock temperature, which indicates a common temperature trend for the geothermal reservoir. However, calcite cements sampled along faults located within the well field showed both cold (18.7°C) and hot (226.1°C) temperatures. The anomalously cool temperature found along the fault, using estimates from clumped isotope thermometry, suggests a possible connection to surface waters for the geothermal source fluids for this system. This information may indicate that some of the faults within the well field are transporting meteoric water from the surface to be heated at depth, which then is circulated through a complex network of fractures and other faults.

Cyclic MrIA: A stable and potent cyclic conotoxin with a novel topological fold that targets the norepinephrine transporter

Conotoxins, disulfide-rich peptides from the venom of cone snails, have created much excitement over recent years due to their potency and specificity for ion channels and their therapeutic potential. One recently identified conotoxin, MrIA, a 13-residue member of the chi-conotoxin family, inhibits the human norepinephrine transporter (NET) and has potential applications in the treatment of pain. In the current study, we show that the, beta-hairpin structure of native MrIA is retained in a synthetic cyclic version, as is biological activity at the NET. Furthermore, the cyclic version has increased resistance to trypsin digestion relative to the native peptide, an intriguing result because the cleavage site for the trypsin is not close to the cyclization site. The use of peptides as drugs is generally hampered by susceptibility to proteolysis, and so, the increase in enzymatic stability against trypsin observed in the current study may be useful in improving the therapeutic potential of MrIA. Furthermore, the structure reported here for cyclic MrIA represents a new topology among a growing number of circular disulfide-rich peptides.

Lyophilisation and sterilisation of liposomal vaccines to produce stable and sterile products

The advantages of liposomes as delivery systems for peptide, protein and DNA vaccines is well-recognised, unfortunately their application has been stinted by their instability during storage and their limited shelf-life. Further, sterilisation of these systems has been problematic, with degradation of the liposomes being reported after sterilisation using the various techniques available. Work form our laboratory has investigated techniques that can be applied to particulate liposomal vaccines such that they can be prepared in a freeze-dried and sterile format. In this article, we describe techniques for the lyophilisation, cryoprotection and sterilisation of liposomal vaccines. Applying these methods allows for the retention of both the chemical integrity of the lipids and the key physico-chemical characteristics of the liposomes (e.g., particle size, zeta potential, and dynamic viscosity), thus supporting the enhanced transition of liposomal vaccines from the bench to the clinic. © 2006 Elsevier Inc. All rights reserved.

On-off and multistate intermittencies in cascaded random distributed feedback fibre laser

A range of physical and engineering systems exhibit an irregular complex dynamics featuring alternation of quiet and burst time intervals called the intermittency. The intermittent dynamics most popular in laser science is the on-off intermittency [1]. The on-off intermittency can be understood as a conversion of the noise in a system close to an instability threshold into effective time-dependent fluctuations which result in the alternation of stable and unstable periods. The on-off intermittency has been recently demonstrated in semiconductor, Erbium doped and Raman lasers [2-5]. Recently demonstrated random distributed feedback (random DFB) fiber laser has an irregular dynamics near the generation threshold [6,7]. Here we show the intermittency in the cascaded random DFB fiber laser. We study intensity fluctuations in a random DFB fiber laser based on nitrogen doped fiber. The laser generates first and second Stokes components 1120 nm and 1180 nm respectively under an appropriate pumping. We study the intermittency in the radiation of the second Stokes wave. The typical time trace near the generation threshold of the second Stokes wave (Pth) is shown at Fig. 1a. From the number of long enough time-traces we calculate statistical distribution between major spikes in time dynamics, Fig. 1b. To eliminate contribution of high frequency components of spikes we use a low pass filter along with the reference value of the output power. Experimental data is fitted by power law, ~(P-Pth)y, where is a mean time between pikes. There are two different intermittency regimes. Just above Pth, the mean time is approximated by the -3/2 power law. The -3/2 power law is typical to the on-off intermittency with hopping between two states (first and second Stokes waves in our case) [7]. At higher power, the mean time is approximated by -4 power law, that indicates a change in intermittency type to multistate. Multistable dynamics is observed in erbium-doped fiber lasers [8]. The origin of multiples states in our system could be probably connected with polarization hopping or other reasons and should be further investigated. We have presented a first experimental statistical characterisation of the on-off and multistate intermittencies that occur in the generation of the second Stokes wave in nitrogen doped random DFB fiber laser. References [1] H. Fujisaka and T. Yamada, “A New Intermittency in Coupled Dynamical Systems,” Prog. Theor. Phys. 74, 918 (1985). [2] S. Osborne, A. Amann, D. Bitauld, and S. O’Brien, “On-off intermittency in an optically injected semiconductor laser,” Phys. Rev. E 85, 056204 (2012). [3] S. Sergeyev, K. O'Mahoney, S. Popov, and A. T. Friberg, “Coherence and anticoherence resonance in high-concentration erbium-doped fiber laser,” Opt. Lett. 35, 3736 (2010). [4] A.E. El-Taher, S.V. Sergeyev, E.G. Turitsyna, P. Harper, and S. K. Turitsyn, “Intermittent Self-Pulsing in a Fiber Raman Laser”, In proc. Conf. Nonlin. Photon., paper ID 1367139, Colorado Springs, USA, 2012 [5] S.K. Turitsyn, S.A. Babin, A.E. El-Taher, P. Harper, D.V. Churkin, S.I. Kablukov, J.D. Ania-Castañón, V. Karalekas, and E.V. Podivilov, “Random distributed feedback fibre laser”, Nat. Photon..4, 231 (2010). [6] I. D. Vatnik, D. V. Churkin, S. A. Babin, and S. K. Turitsyn, "Cascaded random distributed feedback Raman fiber laser operating at 1.2 μm," Opt. Express 19, 18486 (2011). [7] W. Feller, An introduction to probability theory and its applications, Vol. 1, 3rd ed. (Wiley, New-York, 1968). [8] G. Huerta-Cuellar, A.N. Pisarchik, and Y.O. Barmenkov, “Experimental characterization of hopping dynamics in a multistable fiber laser,” Phys. Rev. E 78, 035202(R) (2008).

Dissipative parametric modulation instability and pattern formation in nonlinear optical systems

We present the essential features of the dissipative parametric instability, in the universal complex Ginzburg- Landau equation. Dissipative parametric instability is excited through a parametric modulation of frequency dependent losses in a zig-zag fashion in the spectral domain. Such damping is introduced respectively for spectral components in the +ΔF and in the -ΔF region in alternating fashion, where F can represent wavenumber or temporal frequency depending on the applications. Such a spectral modulation can destabilize the homogeneous stationary solution of the system leading to growth of spectral sidebands and to the consequent pattern formation: both stable and unstable patterns in one- and in two-dimensional systems can be excited. The dissipative parametric instability provides an useful and interesting tool for the control of pattern formation in nonlinear optical systems with potentially interesting applications in technological applications, like the design of mode- locked lasers emitting pulse trains with tunable repetition rate; but it could also find realizations in nanophotonics circuits or in dissipative polaritonic Bose-Einstein condensates.

Proprioception in ankle sprain from exercises and bandages

Ankle sprains are the most common injuries in sports, usually causing damage to the lateral ligaments. Recurrence has as usual result permanent instability, and thus loss of proprioception. This fact, together with residual symptoms, is what is known as chronic ankle instability, CAI, or FAI, if it is functional. This problem tries to be solved by improving musculoskeletal stability and proprioception by the application of bandages and performing exercises. The aim of this study has been to review articles (meta-analisis, systematic reviews and revisions) published in 2009-2015 in PubMed, Medline, ENFISPO and BUCea, using keywords such as “sprain instability”, “sprain proprioception”, “chronic ankle instability”. Evidence affirms that there does exist decreased proprioception in patients who suffer from CAI. Rehabilitation exercise regimen is indicated as a treatment because it generates a subjective improvement reported by the patient, and the application of bandages works like a sprain prevention method limiting the range of motion, reducing joint instability and increasing confidence during exercise. As podiatrists we should recommend proprioception exercises to all athletes in a preventive way, and those with CAI or FAI, as a rehabilitation programme, together with the application of bandages. However, further studies should be generated focusing on ways of improving proprioception, and on the exercise patterns that provide the maximum benefit.

On tubular neighborhoods of piecewise linear and topological manifolds.

Analogues of the smooth tubular neighborhood theorem are developed for the topological and piecewise linear categories.

Small-scale genetic structure of Cerastoderma glaucum in a lagoonal environment: potential significance of habitat discontinuity and unstable population dynamics

Environmental heterogeneity in coastal lagoons is expected to facilitate local adaptation in response to different ecological conditions, causing significant genetic structuring within lagoon populations at a small scale and also differentiation between lagoons. However, these patterns and processes of genetic structuring are still poorly understood. The aims of our study were (1) to seek genetic structure at a small scale in Cerastoderma glaucum inside the Mar Menor coastal lagoon using a mitochondrial DNA marker (COI) that has previously detected genetic differentiation inside the lagoon in other species and (2) to evaluate the influence of extreme environmental conditions and habitat discontinuity on its genetic composition. The results indicate high levels of haplotype diversity and low values of nucleotide diversity. COI data provide evidence of significant population differentiation among some localities within the lagoon. Limited gene flow and unstable population dynamics (i.e. fluctuations in population size caused by local extinction and recolonization), probably due to the high environmental heterogeneity, could generate the small-scale genetic divergence detected between populations within the lagoon.

Preterm birth prediction : deriving stable and interpretable rules from high dimensional data

Preterm births occur at an alarming rate of 10-15%. Preemies have a higher risk of infant mortality, developmental retardation and long-term disabilities. Predicting preterm birth is difficult, even for the most experienced clinicians. The most well-designed clinical study thus far reaches a modest sensitivity of 18.2-24.2% at specificity of 28.6-33.3%. We take a different approach by exploiting databases of normal hospital operations. We aims are twofold: (i) to derive an easy-to-use, interpretable prediction rule with quantified uncertainties, and (ii) to construct accurate classifiers for preterm birth prediction. Our approach is to automatically generate and select from hundreds (if not thousands) of possible predictors using stability-aware techniques. Derived from a large database of 15,814 women, our simplified prediction rule with only 10 items has sensitivity of 62.3% at specificity of 81.5%.

Discovery of stable and variable differences in the Mycobacterium avium subsp. paratuberculosis type I, II, and III genomes by pan-genome microarray analysis

Mycobacterium avium subsp. paratuberculosis is an important animal pathogen widely disseminated in the environment that has also been associated with Crohn's disease in humans. Three M. avium subsp. paratuberculosis genomotypes are recognized, but genomic differences have not been fully described. To further investigate these potential differences, a 60-mer oligonucleotide microarray (designated the MAPAC array), based on the combined genomes of M. avium subsp. paratuberculosis (strain K-10) and Mycobacterium avium subsp. hominissuis (strain 104), was designed and validated. By use of a test panel of defined M. avium subsp. paratuberculosis strains, the MAPAC array was able to identify a set of large sequence polymorphisms (LSPs) diagnostic for each of the three major M. avium subsp. paratuberculosis types. M. avium subsp. paratuberculosis type II strains contained a smaller genomic complement than M. avium subsp. paratuberculosis type I and M. avium subsp. paratuberculosis type III genomotypes, which included a set of genomic regions also found in M. avium subsp. hominissuis 104. Specific PCRs for genes within LSPs that differentiated M. avium subsp. paratuberculosis types were devised and shown to accurately screen a panel (n = 78) of M. avium subsp. paratuberculosis strains. Analysis of insertion/deletion region INDEL12 showed deletion events causing a reduction in the complement of mycobacterial cell entry genes in M. avium subsp. paratuberculosis type II strains and significantly altering the coding of a major immunologic protein (MPT64) associated with persistence and granuloma formation. Analysis of MAPAC data also identified signal variations in several genomic regions, termed variable genomic islands (vGIs), suggestive of transient duplication/deletion events. vGIs contained significantly low GC% and were immediately flanked by insertion sequences, integrases, or short inverted repeat sequences. Quantitative PCR demonstrated that variation in vGI signals could be associated with colony growth rate and morphology.

Myocardial edema after ischemia/reperfusion is not stable and follows a bimodal pattern: Imaging and histological tissue characterization

It is widely accepted that edema occurs early in the ischemic zone and persists in stable form for at least 1 week after myocardial ischemia/reperfusion. However, there are no longitudinal studies covering from very early (minutes) to late (1 week) reperfusion stages confirming this phenomenon. This study sought to perform a comprehensive longitudinal imaging and histological characterization of the edematous reaction after experimental myocardial ischemia/reperfusion. The study population consisted of 25 instrumented Large-White pigs (30 kg to 40 kg). Closed-chest 40-min ischemia/reperfusion was performed in 20 pigs, which were sacrificed at 120 min (n = 5), 24 h (n = 5), 4 days (n = 5), and 7 days (n = 5) after reperfusion and processed for histological quantification of myocardial water content. Cardiac magnetic resonance (CMR) scans with T2-weighted short-tau inversion recovery and T2-mapping sequences were performed at every follow-up stage until sacrifice. Five additional pigs sacrificed after baseline CMR served as controls. In all pigs, reperfusion was associated with a significant increase in T2 relaxation times in the ischemic region. On 24-h CMR, ischemic myocardium T2 times returned to normal values (similar to those seen pre-infarction). Thereafter, ischemic myocardium-T2 times in CMR performed on days 4 and 7 after reperfusion progressively and systematically increased. On day 7 CMR, T2 relaxation times were as high as those observed at reperfusion. Myocardial water content analysis in the ischemic region showed a parallel bimodal pattern: 2 high water content peaks at reperfusion and at day 7, and a significant decrease at 24 h. Contrary to the accepted view, myocardial edema during the first week after ischemia/reperfusion follows a bimodal pattern. The initial wave appears abruptly upon reperfusion and dissipates at 24 h. Conversely, the deferred wave of edema appears progressively days after ischemia/reperfusion and is maximal around day 7 after reperfusion.

Local stability of a gravitating filament: a dispersion relation

Filamentary structures are ubiquitous in astrophysics and are observed at various scales. On a cosmological scale, matter is usually distributed along filaments, and filaments are also typical features of the interstellar medium. Within a cosmic filament, matter can contract and form galaxies, whereas an interstellar gas filament can clump into a series of bead-like structures that can then turn into stars. To investigate the growth of such instabilities, we derive a local dispersion relation for an idealized self-gravitating filament and study some of its properties. Our idealized picture consists of an infinite self-gravitating and rotating cylinder with pressure and density related by a polytropic equation of state. We assume no specific density distribution, treat matter as a fluid, and use hydrodynamics to derive the linearized equations that govern the local perturbations. We obtain a dispersion relation for axisymmetric perturbations and study its properties in the (kR, kz) phase space, where kR and kz are the radial and longitudinal wavenumbers, respectively. While the boundary between the stable and unstable regimes is symmetrical in kR and kz and analogous to the Jeans criterion, the most unstable mode displays an asymmetry that could constrain the shape of the structures that form within the filament. Here the results are applied to a fiducial interstellar filament, but could be extended for other astrophysical systems, such as cosmological filaments and tidal tails.

Effect of temperature on dislocation emission from crack tip for BCC metal Mo

The effect of thermally activated energy on the dislocation emission from a crack tip in BCC metal Mo is simulated in this paper. Based on the correlative reference model on which the flexible displacement boundary scheme is introduced naturally, the simulation shows that as temperature increases the critical stress intensity factor for the first dislocation emission will decrease and the total number of emitted dislocations increase for the same external load. The dislocation velocity and extensive distance among partial dislocations are not sensitive to temperature. After a dislocation emission, two different deformation slates are observed, the stable and unstable deformation states. In the stable deformation slate, the nucleated dislocation will emit from the crack tip and piles up at a distance far away from the crack tip, after that the new dislocation can not be nucleated unless the external loading increases. In the unstable deformation state, a number of dislocations can be emitted from the crack lip continuously under the same external load.

活动构造区区域地壳稳定性研究——以金沙江水电梯级工程规划区为例

The study of regional crustal stability of active tectonic region basically includes analysis of recent activity of Earth's crust, single factor assessment, study of complexity, and comprehensive assessment of crust stability. In this thesis, some work are made as follows: · Based on abundant data from gravity field, aeromagnetic survey, magnetism, magnetotelluric deep sounding, remote sensing and geotectonic as well as earthquakes observed in recent years around this region and adjacent zones, we can get a through understanding about the structural features and activity of the earth's crust in Chuan-Dian region. The results from explosion earthquake and telluric electromagnetic sounding are consistent with the structural features of the crust manifested by the geophysical field. The data of deep geologic structures are important for us to work out a vivid three-dimensional model of the earth's crustal structure of the Jinsha River region. According to a synthesis, the author of this thesis proposes some indicators for dividing the faulted blocks. It can also be inferred that the movement of the Chuan-Dian faulted block, which is the relatively active part of southwestern China, is controlled by the boundary faults, and the intensive activity and deformation are concentrated along the boundaries of the block. · Mainly discussing respectively the mechanism and laws of active faults, earthquakes, and geological hazards activity, and their influences on the stability and security of engineering, also trying to probe into the way to assess the risk of single factor in this section. Especially with the method of fractal geometry, the thesis has discussed how to study the complexity of each factor. These geologic hazards which are distributed at the uppermost part of the crust in this region form a typical mountainous set of the active tectonic areas. The results of survey show that some slopes are liable- to -sliding with a weak layer of low shear strength. Occurrences of landslides are to a great extent related to local geological structures, in particular active faults. This is why numerous landslides have occurred simultaneously around the epicenter of a strong earthquake or the center of a strong rainfall, which are related to active faults. · The analysis of the crustal stability is based on a regional grid division, and a fuzzy comprehensive analysis method is used to determine the grade of the quality in each grid. The evaluation factors and their weights are taken from the results of the hierarchical analysis. The evaluation indexes consist of qualitative and quantitative ones. The qualitative ones can be quantified through the experts weighing system, while the quantitative ones can be obtained from statistical analysis. For quality grades, four levels are used: stable, essentially stable, sub-stable, and unstable. The results of the evaluation on Jinshajiang region demonstrate that the crustal stability become distinctly worse in the areas controlled by active deep faults. Therefore, detailed investigations on the active faulting and geologic hazards, include earthquake activity are especially necessary for those areas adjacent to the deep fault belts. On the bases of the data available and the survey results, we have made a preliminary assessment for the construction conditions and adaptability of every planned site in the middle or lower reaches of Jinsha River. Finally, the thesis prospected the vista of the study of crustal stability.