ALBERT

Description: The predicted effect of effective population size on the distribution of fitness effects and substitution rate is critically dependent on the relationship between sequence and fitness. This highlights the importance of using models that are informed by the molecular biology, biochemistry, and biophysics of the evolving systems. We describe a computational model based on fundamental aspects of biophysics, the requirement for (most) proteins to be thermodynamically stable. Using this model, we find that differences in population size have minimal impact on the distribution of population-scaled fitness effects, as well as on the rate of molecular evolution. This is because larger populations result in selection for more stable proteins that are less affected by mutations. This reduction in the magnitude of the fitness effects almost exactly cancels the greater selective pressure resulting from the larger population size. Conversely, changes in the population size in either direction cause transient increases in the substitution rate. As differences in population size often correspond to changes in population size, this makes comparisons of substitution rates in different lineages difficult to interpret.

Description: A proper orthogonal decomposition (POD) method is used to interpolate the flow around an airfoil for various Mach numbers and angles of attack in the transonic regime. POD uses a few numerical simulations, called snapshots, to create eigenfunctions. These eigenfunctions are combined using weighting coefficients to create a new solution for different values of the input parameters. Since POD methods are linear, their interpolation capabilities are quite limited when dealing with flow presenting nonlinearities, such as shocks. In order to improve their performance for cases involving shocks, a new method is proposed using variable fidelity. The main idea is to use POD to interpolate the difference between the CFD solution obtained on two different grids, a coarse one and a fine one. Then, for any new input parameter value, a coarse grid solution is computed using CFD and the POD interpolated difference is added to predict the fine grid solution. This allows some nonlinearities associated with the flow to be introduced. Results for various Mach numbers and angles of attack are compared to full CFD results. The variable fidelity-based POD method shows good improvement over the classical approach.

Description: The preparation of carbon nanotube/metallic particle hybrids using pressed porous stainless steel pellets as a substrate is described. The catalytic growth of carbon nanotubes was carried out by CVD on a nickel catalyst obtained by impregnation of pellets with a highly dispersive colloidal solution of nickel acetate tetrahydrate in ethanol. Granular polyethylene was used as the carbon source. Metallic particles were deposited by thermal evaporation of Pt and Ag using pellets with grown carbon nanotubes as a base. The use of such composites as fuel cell electrodes is discussed.

Description: In the title compound, [CdBr2(C8H8N2)2], the CdII atom has a distorted tetrahedral coordination formed by the two imino N atoms of two 2-methylbenzimidazole ligands and two terminal bromide ligands. The CdII atom is slightly out of the benzimidazole planes by 0.320 (3) and 0.210 (3) Å. The dihedral angle between the benzimidazole planes is 71.6 (2)°. In the crystal, molecules are linked by N—H...Br hydrogen bonds into puckered layers parallel to (001).

Description: In the title hydrated molecular salt, C22H25N2+·C6H4FO3S−·H2O, the cation displays whole molecule disorder over two sets of sites in a 0.780 (5):0.220 (5) ratio. The quinolinium ring system is essentially planar, with r.m.s. deviations of 0.0162 and 0.0381 Å for the major and minor disorder components, respectively. The dihedral angles between the mean plane of the quinolinium ring system and the benzene ring are 5.1 (3) and 7.7 (11)°, respectively, for the major and minor components in the cation. In the crystal, cations, anions and water molecules are linked into chains along [010] by O—H...O hydrogen bonds and are further connected into a three-dimensional network by weak C—H...O and C—H...F interactions. In addition, π–π interactions with centroid–centroid distances of 3.634 (3), 3.702 (5) and 3.838 (5) Å are observed.

Description: In the title compound, C20H19NOS, the pyrrolizine ring is essentially planar (r.m.s. deviation = 0.001 Å) while the fused dihydro-pyrrolizine ring adopts an envelope comformation with the C atom bearing the methyl substituents as the flap. The dihedral angles between the pyrrolizine and the phenyl and thiophene rings are 34.54 (7) and 44.93 (7)°, respectively. In the crystal, weak C—H...O hydrogen bonds link the molecules into infinite zigzag chains parallel to the b-axis direction.

Description: In the title compound, C27H22N2O4, the two indole ring systems are approximately perpendicular to each other, with a dihedral angle of 84.5 (5)° between their planes; the benzene ring is twisted with respect to the two indole ring systems at angles of 78.5 (5) and 86.5 (3)°. In the crystal, molecules are linked by N—H...O hydrogen bonds, weak C—H...O and C—H...N hydrogen bonds, and C—H...π interactions into a three-dimensional supramolecular architecture.

Description: The title compound, C9H3F5O2, crystallizes as O—H...O hydrogen-bonded carboxylic acid dimers that, together with C—H...F interactions and O...F [2.8065 (13) and 2.9628 (13) Å] and F...F [2.6665 (11), 2.7049 (12) and 2.7314 (12) Å] contacts, form a sheet-like structure. The sheets are stacked via short π–π interactions [centroid–centroid distance = 4.3198 (11) Å]. An intramolecular C—H...F interaction is also observed.

Description: The asymmetric unit of the title compound, C12H12ClNOS, contains three independent molecules, with the thiochroman ring adopting a sofa conformation in each one. The crystal structure features C—H...O interactions; one of the O atoms accepts three such bonds. Together, the hydrogen bonds give rise to a molecular tape propagating in [010].

Description: In the title molecule, C30H35NO8, the acenaphthylenone moiety, two atoms of a methyl pyrrolidine ring (N and C atoms) and four atoms of an ethyl acetate moiety (two C and two O atoms) are disordered over two sets of sites in ratio 0.532 (7):0.468 (7). The three C atoms of a dimethoxyethane ring and dioxolane ring attached with two methyl groups are disordered over two sets of sites in 0.66 (2):0.34 (2) and 0.62 (2):0.38 (2) ratios, respectively. The major and minor components of the acenaphthylene ring are essentially planar (r.m.s. deviations = 0.0254 and 0.0436 Å, respectively). The major and minor components of the pyrrolidine ring adopt C-envelope conformations with C atoms displaced by 0.492 (11) and 0.595 (7) Å from the remaining ring atoms. One of the dioxolane rings is disordered with its major component in an envelope conformation [C displaced by 0.511 (11) Å] and the minor fraction is more or less planar with an r.m.s. deviation of 0.070 Å. The other dioxolane ring is in an envelope conformation, with a C atom displaced by 0.438 (3) Å from the remainder of the ring atoms. The crystal packing features C—H...O interactions, which generate C(9) chains.

Description: O -GlcNAcylation is an inducible, highly dynamic and reversible post-translational modification, mediated by a unique enzyme named O -linked N -acetyl- d -glucosamine ( O -GlcNAc) transferase (OGT). In response to nutrients, O -GlcNAc levels are differentially regulated on many cellular proteins involved in gene expression, translation, immune reactions, protein degradation, protein–protein interaction, apoptosis and signal transduction. In contrast to eukaryotic cells, little is known about the role of O -GlcNAcylation in the viral life cycle. Here, we show that the overexpression of the OGT reduces the replication efficiency of Kaposi's sarcoma-associated herpesvirus (KSHV) in a dose-dependent manner. In order to investigate the global impact of O -GlcNAcylation in the KSHV life cycle, we systematically analyzed the 85 annotated KSHV-encoded open reading frames for O -GlcNAc modification. For this purpose, an immunoprecipitation (IP) strategy with three different approaches was carried out and the O -GlcNAc signal of the identified proteins was properly controlled for specificity. Out of the 85 KSHV-encoded proteins, 18 proteins were found to be direct targets for O -GlcNAcylation. Selected proteins were further confirmed by mass spectrometry for O -GlcNAc modification. Correlation of the functional annotation and the O -GlcNAc status of KSHV proteins showed that the predominant targets were proteins involved in viral DNA synthesis and replication. These results indicate that O -GlcNAcylation plays a major role in the regulation of KSHV propagation.

Description: Galectins are potent adhesion/growth-regulatory effectors with characteristic expression profiles. Understanding the molecular basis of gene regulation in each case requires detailed information on copy number of genes and sequence(s) of their promoter(s). Our report reveals plasticity in this respect between galectins and species. We here describe occurrence of a two-gene constellation for human galectin (Gal)-7 and define current extent of promoter-sequence divergence. Interestingly, cross-species genome analyses also detected single-copy display. Because the regulatory potential will then be different, extrapolations of expression profiles are precluded between respective species pairs. Gal-4 coding in chromosomal vicinity was found to be confined to one gene, whereas copy-number variation also applied to Gal-9. The example of rat Gal-9 teaches the lesson that the presence of multiple bands in Southern blotting despite a single-copy gene constellation is attributable to two pseudogenes. The documented copy-number variability should thus be taken into consideration when studying regulation of galectin genes, in a species and in comparison between species.

Description: In studying the molecular basis for the potent immune activity of previously described gamma and delta inulin particles and to assist in production of inulin adjuvants under Good Manufacturing Practice, we identified five new inulin isoforms, bringing the total to seven plus the amorphous form. These isoforms comprise the step-wise inulin developmental series amorphous -〉 alpha-1 (AI-1) -〉 alpha-2 (AI-2) -〉 gamma (GI) -〉 delta (DI) -〉 zeta (ZI) -〉 epsilon (EI) -〉 omega (OI) in which each higher isoform can be made either by precipitating dissolved inulin or by direct conversion from its precursor, both cases using regularly increasing temperatures. At higher temperatures, the shorter inulin polymer chains are released from the particle and so the key difference between isoforms is that each higher isoform comprises longer polymer chains than its precursor. An increasing trend of degree of polymerization is confirmed by end-group analysis using 1 H nuclear magnetic resonance spectroscopy. Inulin isoforms were characterized by the critical temperatures of abrupt phase-shifts (solubilizations or precipitations) in water suspensions. Such (aqueous) "melting" or "freezing" points are diagnostic and occur in strikingly periodic steps reflecting quantal increases in noncovalent bonding strength and increments in average polymer lengths. The (dry) melting points as measured by modulated differential scanning calorimetry similarly increase in regular steps. We conclude that the isoforms differ in repeated increments of a precisely repeating structural element. Each isoform has a different spectrum of biological activities and we show the higher inulin isoforms to be more potent alternative complement pathway activators.

Description: The methylotrophic yeast, Pichia pastoris , is an important organism used for the production of therapeutic proteins. Previously, we have reported the glycoengineering of this organism to produce human-like N -linked glycans but up to now no one has addressed engineering the O -linked glycosylation pathway. Typically, O -linked glycans produced by wild-type P. pastoris are linear chains of four to five α-linked mannose residues, which may be capped with β- or phospho-mannose. Previous genetic engineering of the N-linked glycosylation pathway of P. pastoris has eliminated both of these two latter modifications, resulting in O -linked glycans which are linear α-linked mannose structures. Here, we describe a method for the co-expression of an α-1,2-mannosidase, which reduces these glycans to primarily a single O -linked mannose residue. In doing so, we have reduced the potential of these glycans to interact with carbohydrate-binding proteins, such as dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin. Furthermore, the introduction of the enzyme protein- O -linked-mannose β-1,2- N -acetylglucosaminyltransferase 1, resulted in the capping of the single O -linked mannose residues with N -acetylglucosamine. Subsequently, this glycoform was extended into human-like sialylated glycans, similar in structure to α-dystroglycan-type glycoforms. As such, this represents the first example of sialylated O -linked glycans being produced in yeast and extends the utility of the P. pastoris production platform beyond N -linked glycosylated biotherapeutics to include molecules possessing O -linked glycans.

Description: Neurons and other cells require intracellular transport of essential components for viability and function. Previous work has shown that while net amyloid precursor protein (APP) transport is generally anterograde, individual vesicles containing APP move bi-directionally. This discrepancy highlights our poor understanding of the in vivo regulation of APP-vesicle transport. Here, we show that reduction of presenilin (PS) or suppression of gamma-secretase activity substantially increases anterograde and retrograde velocities for APP vesicles. Strikingly, PS deficiency has no effect on an unrelated cargo vesicle class containing synaptotagmin, which is powered by a different kinesin motor. Increased velocities caused by PS or gamma-secretase reduction require functional kinesin-1 and dynein motors. Together, our findings suggest that a normal function of PS is to repress kinesin-1 and dynein motor activity during axonal transport of APP vesicles. Furthermore, our data suggest that axonal transport defects induced by loss of PS-mediated regulatory effects on APP-vesicle motility could be a major cause of neuronal and synaptic defects observed in Alzheimer's Disease (AD) pathogenesis. Thus, perturbations of APP/PS transport could contribute to early neuropathology observed in AD, and highlight a potential novel therapeutic pathway for early intervention, prior to neuronal loss and clinical manifestation of disease.

Description: With age, muscle mass and integrity are progressively lost leaving the elderly frail, weak and unable to independently care for themselves. Defined as sarcopenia, this age-related muscle atrophy appears to be multifactorial but its definite cause is still unknown. Mitochondrial dysfunction has been implicated in this process. Using a novel transgenic mouse model of mitochondrial DNA (mtDNA) double-strand breaks (DSBs) that presents a premature aging-like phenotype, we studied the role of mtDNA damage in muscle wasting. We caused DSBs in mtDNA of adult mice using a ubiquitously expressed mitochondrial-targeted endonuclease, mito- Pst I. We found that a short, transient systemic mtDNA damage led to muscle wasting and a decline in locomotor activity later in life. We found a significant decline in muscle satellite cells, which decreases the muscle's capacity to regenerate and repair during aging. This phenotype was associated with impairment in acetylcholinesterase (AChE) activity and assembly at the neuromuscular junction (NMJ), also associated with muscle aging. Our data suggests that systemic mitochondrial dysfunction plays important roles in age-related muscle wasting by preferentially affecting the myosatellite cell pool.

Description: Populations of widely distributed species encounter and must adapt to local environmental conditions. However, comprehensive characterization of the genetic basis of adaptation is demanding, requiring genome-wide genotype data, multiple sampled populations, and an understanding of population structure and potential selection pressures. Here, we used single-nucleotide polymorphism genotyping and data on numerous environmental variables to describe the genetic basis of local adaptation in 21 populations of teosinte, the wild ancestor of maize. We found complex hierarchical genetic structure created by altitude, dispersal events, and admixture among subspecies, which complicated identification of locally beneficial alleles. Patterns of linkage disequilibrium revealed four large putative inversion polymorphisms showing clinal patterns of frequency. Population differentiation and environmental correlations suggest that both inversions and intergenic polymorphisms are involved in local adaptation.

Description: We present a methodology for infrasonic remote sensing of winds in the stratosphere that does not require discrete ground-truth events. Our method uses measured time delays between arrays of sensors to provide group velocities (referred to here as celerities) and then minimizes the difference between observed and predicted celerities by perturbing an initial atmospheric specification. Because we focus on interarray propagation effects, it is not necessary to simulate the full propagation path from source to receiver. This feature allows us to use a relatively simple forward model that is applicable over short-regional distances. By focusing on stratospheric returns, we show that our non-linear inversion scheme converges much better if the starting model contains a strong stratospheric duct. Using the Horizontal Wind Model (HWM)/Mass Spectrometer Incoherent Scatter (MSISE) empirical climatology as a starting model, we demonstrate that the inversion scheme is robust to large uncertainties in backazimuth, but that uncertainties in the measured trace velocity and celerity require the use of prior constraints to ensure suitable convergence. The inversion of synthetic data, using realistic estimates of measurement error, shows that our scheme will nevertheless improve upon a starting model under most scenarios. The inversion scheme is applied to infrasound data recorded from a large event on 2010 December 25, which is presumed to be a bolide, using data from a nine-element infrasound network in Utah. We show that our recorded data require a stronger zonal wind speed in the stratosphere than is present in the HWM profile, and are more consistent with the Ground-to-Space (G2S) profile.

Description: Coda- Q is a stochastic parameter reflecting the heterogeneities of medium that seismic waves travel through. We confirmed that coda- Q would vary with the stress loaded to an elastic medium using numerical simulations of seismic wave propagation. When the stress is loaded, cracks in the crust could either close or newly open. The closure and opening of the cracks are not random but depending on the magnitude and the direction of the stress and the crack aspect ratio. The cracks in the medium after loading stress could be aligned in a specific orientation, and elastic wave velocity field would become anisotropic due to the alignment of specific crack orientations. Elastic wave velocity is in general faster along the direction corresponding with the crack orientation while slower along the perpendicular direction. In the numerical simulation, the effect of anisotropy in elastic wave velocity field due to the selective closure and opening of the cracks is calculated using a 2-D finite difference method assuming elastic wave velocity to be a function of the magnitude of loaded stress. The coda- Q calculated from seismic waves simulated for a model varies when the averaged normal stress changes. Our simulation indicated that the sensitivity of coda- Q –1 , that is the reciprocal of the coda- Q , would be 1.0 10 –2 (1.0 MPa –1 ) against the magnitude of the confining pressure and 1.0 10 –3 (1.0 deg –1 ) against the direction of principal stress. We would like to conclude that coda- Q , a stochastic parameter reflecting heterogeneities of subsurface medium, could become a quantitative state indicator of the stress field of the medium where seismic waves propagate through. Spatiotemporal variation of coda- Q reflects change in the stress field in the crust.

Description: How do body-wave traveltimes constrain the Earth's radial (1-D) seismic structure? Existing 1-D seismological models underpin 3-D seismic tomography and earthquake location algorithms. It is therefore crucial to assess the quality of such 1-D models, yet quantifying uncertainties in seismological models is challenging and thus often ignored. Ideally, quality assessment should be an integral part of the inverse method. Our aim in this study is twofold: (i) we show how to solve a general Bayesian non-linear inverse problem and quantify model uncertainties, and (ii) we investigate the constraint on spherically symmetric P -wave velocity ( V P ) structure provided by body-wave traveltimes from the EHB bulletin (phases Pn , P , PP and PKP ). Our approach is based on artificial neural networks, which are very common in pattern recognition problems and can be used to approximate an arbitrary function. We use a Mixture Density Network to obtain 1-D marginal posterior probability density functions (pdfs), which provide a quantitative description of our knowledge on the individual Earth parameters. No linearization or model damping is required, which allows us to infer a model which is constrained purely by the data. We present 1-D marginal posterior pdfs for the 22 V P parameters and seven discontinuity depths in our model. P -wave velocities in the inner core, outer core and lower mantle are resolved well, with standard deviations of ~0.2 to 1 per cent with respect to the mean of the posterior pdfs. The maximum likelihoods of V P are in general similar to the corresponding ak135 values, which lie within one or two standard deviations from the posterior means, thus providing an independent validation of ak135 in this part of the radial model. Conversely, the data contain little or no information on P -wave velocity in the D '' layer, the upper mantle and the homogeneous crustal layers. Further, the data do not constrain the depth of the discontinuities in our model. Using additional phases available in the ISC bulletin, such as PcP , PKKP and the converted phases SP and ScP , may enhance the resolvability of these parameters. Finally, we show how the method can be extended to obtain a posterior pdf for a multidimensional model space. This enables us to investigate correlations between model parameters.

Description: We have developed a network optimization method for regional-scale microseismic monitoring networks and applied it to optimize the densification of the existing seismic network in northeastern Switzerland. The new network will build the backbone of a 10-yr study on the neotectonic activity of this area that will help to better constrain the seismic hazard imposed on nuclear power plants and waste repository sites. This task defined the requirements regarding location precision (0.5 km in epicentre and 2 km in source depth) and detection capability [magnitude of completeness M c  = 1.0 ( M L )]. The goal of the optimization was to find the geometry and size of the network that met these requirements. Existing stations in Switzerland, Germany and Austria were considered in the optimization procedure. We based the optimization on the simulated annealing approach proposed by Hardt & Scherbaum, which aims to minimize the volume of the error ellipsoid of the linearized earthquake location problem ( D -criterion). We have extended their algorithm to: calculate traveltimes of seismic body waves using a finite difference ray tracer and the 3-D velocity model of Switzerland, calculate seismic body-wave amplitudes at arbitrary stations assuming the Brune source model and using scaling and attenuation relations recently derived for Switzerland, and estimate the noise level at arbitrary locations within Switzerland using a first-order ambient seismic noise model based on 14 land-use classes defined by the EU-project CORINE and open GIS data. We calculated optimized geometries for networks with 10–35 added stations and tested the stability of the optimization result by repeated runs with changing initial conditions. Further, we estimated the attainable magnitude of completeness ( M c ) for the different sized optimal networks using the Bayesian Magnitude of Completeness (BMC) method introduced by Mignan et al. The algorithm developed in this study is also applicable to smaller optimization problems, for example, small local monitoring networks. Possible applications are volcano monitoring, the surveillance of induced seismicity associated with geotechnical operations and many more. Our algorithm is especially useful to optimize networks in populated areas with heterogeneous noise conditions and if complex velocity structures or existing stations have to be considered.

Description: Fluid injection in and withdrawal from wells are basic procedures in mining activities and deep resources exploitation, such as oil and gas extraction, permeability enhancement for geothermal exploitation and waste fluid disposal. All of these activities have the potential to induce seismicity, as exemplified by the 2006 Basel earthquake ( M L 3.4). Despite several decades of experience, the mechanisms of induced seismicity are not known in detail, which prevents effective risk assessment and/or mitigation. In this study, we provide an interpretation of induced seismicity based on computation of Coulomb stress changes that result from fluid injection/withdrawal at depth, mainly focused on the interpretation of induced seismicity due to stimulation of a geothermal reservoir. Seismicity is, theoretically, more likely where Coulomb stress changes are larger. For modeling purposes, we simulate the thermodynamic evolution of a system after fluid injection/withdrawal. The associated changes in pressure and temperature are subsequently considered as sources of incremental stress changes, which are then converted to Coulomb stress changes on favourably oriented faults, taking into account the background regional stress. Numerical results are applied to the water injection that was performed to create the fractured reservoir at the enhanced-geothermal-system site, Soultz-sous-Forets (France). Our approach describes well the observed seismicity, and provides an explanation for the different behaviors of a system when fluids are injected or withdrawn.

Description: We report on a broad-band high-resolution attenuation model for the North China Craton and surrounding regions based on regional Lg -wave data. Vertical broad-band waveforms recorded at 39 stations from 176 crustal earthquakes are collected to extract the Lg -wave amplitude spectra between 0.05 and 10.0 Hz. We use the dual-station method to generate a preliminary Q Lg model and use it as the initial model. Then, we combine the dual- and single-station data together to jointly invert the Q Lg distribution and Lg source excitation functions. These inversions are conducted independently at individual frequencies without using any a priori assumption about the frequency dependences in Q Lg and source terms. The maximum spatial resolution is approximately 1° x 1° in well-covered areas for frequencies between 0.05 and 2.0 Hz. The Q Lg image is then used to determine the relationship between the attenuation and different geological structures. Results show an average Q 0 (1 Hz Q Lg ) of 374 for the entire North China Craton with an increasing trend from east to west. Average Q 0 values are 337, 361 and 421 for the east, central and west blocks, respectively. For the surrounding regions, the Eastern Tibetan plateau has a very low Q 0 of 188, while the Northeast China Plate and the Tianshan–Xingmeng fold belts are characterized by high Q 0 values of 506 and 424, respectively. We also investigate regional variations of the Lg attenuation in low-frequency band between 0.2 and 1.0 Hz.

Description: We present a systematic study on the influence of pressure (0.1–600 MPa), temperature (750–1200 °C), carbon dioxide fugacity (log f CO 2  = –4.41 to 3.60) and time (2–12 hr) on the chemical and physical properties of carbonate rock. Our experiments aim to reproduce the conditions at the periphery of magma chamber where carbonate host rock is influenced by, but not readily assimilated by, magma. This permits the investigation of the natural conditions at which circulating fluids/gases promote infiltration reactions typical of metasomatic skarns that can involve large volumes of subvolcanic carbonate basements. Results show that, providing that carbon dioxide is retained in the pore space, decarbonation does not proceed at any magmatic pressure and temperature. However, when the carbon dioxide is free to escape, decarbonation can occur rapidly and is not hindered by a low initial porosity or permeability. Together with carbon dioxide and lime, portlandite, a mineral commonly found in voluminous metasomatic skarns, readily forms during carbonate decomposition. Post-experimental analyses highlight that thermal microcracking, a result of the highly anisotropic thermal expansion of calcite, exerts a greater influence on rock physical properties (porosity, ultrasonic wave velocities and elastic moduli) than decarbonation. Our data suggest that this will be especially true at the margins of dykes or magma bodies, where temperatures can reach up to 1200 °C. However, rock compressive strength is significantly reduced by both thermal cracking and decarbonation, explained by the relative weakness of lime + portlandite compared to calcite, and an increase in grain size with increasing temperature. Metasomatic skarns, whose petrogenetic reactions may involve a few tens of cubic kilometres, could therefore represent an important source of volcanic instability.

Description: The scattering of plane SH waves incident on a circular sectorial canyon is considered. An accurate region-matching technique is applied to derive a rigorous series solution. Appropriate wavefunctions are employed to describe antiplane motions. Judicious basis functions, involving Gegenbauer polynomials, are well utilized to correctly capture the singular behaviour in stress fields near the canyon bottom. The enforcement of matching conditions on the auxiliary boundary leads to the determination of unknown coefficients. Plotted results demonstrate the influence of pertinent parameters on surface and subsurface motions. Both steady-state and transient results are included. The solution technique proposed achieves a considerable reduction in the computational effort, facilitating benchmark computations. The derived series solution enriches the limited list of series solutions presently known for canyon problems related to SH -wave scattering.

Description: We present 3-D models of the P- and S -wave velocity distributions in the crust and uppermost mantle beneath Sicily, Calabria (Southern Italy), and surrounding submerged areas, obtained by tomographic inversion of traveltimes of regional body waves phases. Our method combines double-difference tomographic inversion with a post-processing procedure [Weighted Average Model method (WAM)]. This procedure was applied to a set of models consistent with the experimental data. We tested the ability of the WAM procedure to mitigate the uncertainty associated with the arbitrary nature of the many input parameters required for each inversion. The local reliability and resolution of the obtained models have been assessed through: synthetic tests, experimental tests carried out with independent data sets and unconventional tests based on the analysis of the internal consistency of the P - and S -velocity models. The tomographic images provide a detailed sketch of P- and S- wave velocity anomalies. These clearly show the shape of the Sicilian-Maghrebian belt beneath Sicily and Calabrian Arc at different depths. Low V P and Vs bodies are imaged beneath Stromboli and Marsili volcanoes in the southern Tyrrhenian, whereas high and low seismic velocities alternate beneath the Etna giving inferences on the possible depth of the mantle melting feeding the volcano. In the upper crust, the main sedimentary basins and tectonic features are also well imaged. Finally, tomographic cross sections show the trend of the Moho in the study area, where its depth ranges between 35 and 40 km beneath the Sicilian belt and between 15 and 22 km in the southern Tyrrhenian basin and Ionian Sea.

Description: We used two tracks of ALOS PALSAR images to investigate the focal mechanism and slip distribution of the 2011 March 24, M W 6.8 Burma strike-slip earthquake. Three different SAR techniques, namely conventional interferometry, SAR pixel offsets (SPO) and multiple-aperture InSAR (MAI), were employed to obtain the coseismic surface deformation fields along the ~30 km length of the fault rupture. Along-track measurements from SPO and MAI techniques show a high correlation, and were subsequently used to precisely determine the location and extent of the surface fault trace. The best-fitting fault model geometry derived from an iterative inversion technique suggests that the rupture occurred on a near-vertical sinistral strike-slip fault west of the Nam Ma fault with a strike of 70°. A maximum slip of 4.2 m occurs at a depth of 2.5 km, with significant slip constrained only to the upper 10 km of the crust.

Description: Knowledge of the mantle reflectivity structure is highly dependent on our ability to efficiently extract, and properly interpret, small seismic arrivals. Among the various data types and techniques, long-period SS/PP precursors and high-frequency receiver functions are routinely utilized to increase the confidence of the recovered mantle stratifications at distinct spatial scales. However, low resolution and a complex Fresnel zone are glaring weaknesses of SS precursors, while over-reliance on receiver distribution is a formidable challenge for the analysis of converted waves from oceanic regions. A promising high frequency alternative to receiver functions is P ' P ' precursors, which are capable of resolving mantle structures at vertical and lateral resolution of ~5 and ~200 km, respectively, owing to their spectral content, shallow angle of incidence and near-symmetric Fresnel zones. This study presents a novel processing method for both SS (or PP) and P ' P ' precursors based on deconvolution, stacking, Radon transform and depth migration. A suite of synthetic tests is performed to quantify the fidelity and stability of this method under different data conditions. Our multiresolution survey of the mantle at targeted areas near Nazca-South America subduction zone reveal both olivine and garnet related transitions at depths below 400 km. We attribute a depressed 660 to thermal variations, whereas compositional variations atop the upper-mantle transition zone are needed to explain the diminished or highly complex reflected/scattered signals from the 410 km discontinuity. We also observe prominent P ' P ' reflections within the transition zone, and the anomalous amplitudes near the plate boundary zone indicate a sharp (~10 km thick) transition that likely resonates with the frequency content of P ' P ' precursors. The migration of SS precursors in this study shows no evidence of split 660 reflections, but potential majorite–ilmenite (590–640 km) and ilmenite–perovskite transitions (740–750 km) are identified based on similarly processed high-frequency P ' P ' precursors. Additional findings of severely scattered energy in the lithosphere and distinct lower mantle reflections at ~800 km could be potentially important but require further verifications. Overall, our improved imaging methods and the strong sensitivity of P ' P ' precursors to the existence, depth, sharpness and strength of reflective structures offer significant future promise for the understanding of mantle mineralogy and dynamics.

Description: Time-dependent probabilistic seismic hazard assessment requires a stochastic description of earthquake occurrences. While short-term seismicity models are well-constrained by observations, the recurrences of characteristic on-fault earthquakes are only derived from theoretical considerations, uncertain palaeo-events or proxy data. Despite the involved uncertainties and complexity, simple statistical models for a quasi-period recurrence of on-fault events are implemented in seismic hazard assessments. To test the applicability of statistical models, such as the Brownian relaxation oscillator or the stress release model, we perform a systematic comparison with deterministic simulations based on rate- and state-dependent friction, high-resolution representations of fault systems and quasi-dynamic rupture propagation. For the specific fault network of the Lower Rhine Embayment, Germany, we run both stochastic and deterministic model simulations based on the same fault geometries and stress interactions. Our results indicate that the stochastic simulators are able to reproduce the first-order characteristics of the major earthquakes on isolated faults as well as for coupled faults with moderate stress interactions. However, we find that all tested statistical models fail to reproduce the characteristics of strongly coupled faults, because multisegment rupturing resulting from a spatiotemporally correlated stress field is underestimated in the stochastic simulators. Our results suggest that stochastic models have to be extended by multirupture probability distributions to provide more reliable results.

Description: Stress waves, known as acoustic emissions (AEs), are released by localized inelastic deformation events during the progressive failure of brittle rocks. Although several numerical models have been developed to simulate the deformation and damage processes of rocks, such as non-linear stress–strain behaviour and localization of failure, only a limited number have been capable of providing quantitative information regarding the associated seismicity. Moreover, the majority of these studies have adopted a pseudo-static approach based on elastic strain energy dissipation that completely disregards elastodynamic effects. This paper describes a new AE modelling technique based on the combined finite-discrete element method (FEM/DEM), a numerical tool that simulates material failure by explicitly considering fracture nucleation and propagation in the modelling domain. Given the explicit time integration scheme of the solver, stress wave propagation and the effect of radiated seismic energy can be directly captured. Quasi-dynamic seismic information is extracted from a FEM/DEM model with a newly developed algorithm based on the monitoring of internal variables (e.g. relative displacements and kinetic energy) in proximity to propagating cracks. The AE of a wing crack propagation model based on this algorithm are cross-analysed by traveltime inversion and energy estimation from seismic recordings. Results indicate a good correlation of AE initiation times and locations, and scaling of energies, independently calculated with the two methods. Finally, the modelling technique is validated by simulating a laboratory compression test on a granite sample. The micromechanical parameters of the heterogeneous model are first calibrated to reproduce the macroscopic stress–strain response measured during standard laboratory tests. Subsequently, AE frequency–magnitude statistics, spatial clustering of source locations and the evolution of AE rate are investigated. The distribution of event magnitude tends to decay as power law while the spatial distribution of sources exhibits a fractal character, in agreement with experimental observations. Moreover, the model can capture the decrease of seismic b value associated with the macrorupture of the rock sample and the transition of AE spatial distribution from diffuse, in the pre-peak stage, to strongly localized at the peak and post-peak stages, as reported in a number of published laboratory studies. In future studies, the validated FEM/DEM-AE modelling technique will be used to obtain further insights into the micromechanics of rock failure with potential applications ranging from laboratory-scale microcracking to engineering-scale processes (e.g. excavations within mines, tunnels and caverns, petroleum and geothermal reservoirs) to tectonic earthquakes triggering.

Description: We used strong-motion records from the 2012 May 20 and 29 Emilia-Romagna earthquakes ( M w 6.1 and 5.9, respectively) and four aftershocks with magnitudes ranging between 4.9 and 5.5 to analyse the S -wave spectral amplitude decay with distance and estimate acceleration source functions and site effects. The data set consists of six earthquakes, 44 stations and 248 records with hypocentral distances in the range 10 〈 r  〈 100 km. We rotated the accelerograms to calculate transverse and radial components of the acceleration spectrum. We found non-parametric attenuation functions that describe the spectral amplitude decay of SH and SV waves with distance at 60 different frequencies between 0.1 and 40 Hz. These attenuation functions provide an estimate of the quality factor Q at each frequency analysed. Assuming that geometrical spreading is 1/ r for r  ≤ r x and 1/( r x r ) 0.5 for r  〉 r x with r x  = 60 km and normalizing at 15 km (the recording distance where the attenuation functions start to decay), we find that the average Q for SH waves can be approximated by Q SH  = 82 ± 1 f  1.2±0.02 and by Q SV  = 79 ± 1 f  1.24±0.03 for SV waves in the frequency range 0.10 ≤ f  ≤ 10.7 Hz. At higher frequencies, 11.8 ≤ f  ≤ 40 Hz, the frequency dependence of Q weakens and is approximated by Q SH  = 301 ± 1 f   0.36±0.04 and Q SV  = 384 ± 1 f  0.28±0.04 . These results indicate that the S -wave attenuation is radially isotropic at local distances in the epicentral area. Nevertheless, we used these attenuation parameters separately to correct the radial (with Q SV ) and transverse (with Q SH ) components of the acceleration spectra and to separate source and site effects using a non-parametric spectral inversion scheme. We found that the source function of the main event and the bigger aftershocks show enhanced low frequency radiation between 0.4 and 3.0 Hz. We converted the source functions into far-field source acceleration spectra and interpreted the resulting source spectra in terms of Brune's model. The stress drops obtained range between approximately 0.9 and 2.9 MPa. Although all the recording stations used are located in the Po Plain, the site functions obtained from the spectral inversion show important amplification variability between the sites. We compared these site functions with the average horizontal to vertical spectral ratios calculated for each station, and we found consistent results for most stations.

Description: This work provides a distributed fault-tolerant event region detection algorithm for wireless sensor networks. The proposed algorithm can identify faulty and fault-free sensors and ignore the abnormal readings to avoid false alarm. Moreover, every event region can also be detected and identified. Simulation results show that fault detection accuracy (FDA) is greater than 92%, false alarm rate (FAR) is near 0%, and event detection accuracy (EDA) is greater than 99% under uniform distribution. FDA is greater than 92%, FAR is less than 1.2%, and EDA is greater than 88% under random distribution when sensor fault probability is less than 0.3.

Description: Pupylation, one of the most important posttranslational modifications of proteins, typically takes place when prokaryotic ubiquitin-like protein (Pup) is attached to specific lysine residues on a target protein. Identification of pupylation substrates and their corresponding sites will facilitate the understanding of the molecular mechanism of pupylation. Comparing with the labor-intensive and time-consuming experiment approaches, computational prediction of pupylation sites is much desirable for their convenience and fast speed. In this study, a new bioinformatics tool named EnsemblePup was developed that used an ensemble of support vector machine classifiers to predict pupylation sites. The highlight of EnsemblePup was to utilize the Bi-profile Bayes feature extraction as the encoding scheme. The performance of EnsemblePup was measured with a sensitivity of 79.49%, a specificity of 82.35%, an accuracy of 85.43%, and a Matthews correlation coefficient of 0.617 using the 5-fold cross validation on the training dataset. When compared with other existing methods on a benchmark dataset, the EnsemblePup provided better predictive performance, with a sensitivity of 80.00%, a specificity of 83.33%, an accuracy of 82.00%, and a Matthews correlation coefficient of 0.629. The experimental results suggested that EnsemblePup presented here might be useful to identify and annotate potential pupylation sites in proteins of interest. A web server for predicting pupylation sites was developed.

Description: We used a one-dimensional simulation program Solar Cell Capacitance Simulator in 1 Dimension (SCAPS-1D) to investigate Copper-Indium-Gallium-Diselenide- (CIGS-) based solar cells properties. Starting with a conventional ZnO-B/i-ZnO/CdS/CIGS structure, we simulated the parameters of current-voltage characteristics and showed how the absorber layer thickness, hole density, and band gap influence the short-circuit current density (), open-circuit voltage (), fill factor (FF), and efficiency of solar cell. Our simulation results showed that all electrical parameters are greatly affected by the absorber thickness (w) below 1000 nm, due to the increase of back-contact recombination and very poor absorption. Increasing hole density (p) or absorber band gap () improves and leads to high efficiency, which equals value of 16.1% when p = 1016 cm−3 and  eV. In order to reduce back-contact recombination, the effect of a very thin layer with high band gap inserted near the back contact and acting as electrons reflector, the so-called back-electron reflector (EBR), has been investigated. The performances of the solar cells are significantly improved, when ultrathin absorbers (w 〈 500 nm) are used; the corresponding gain of due to the EBR is 3 mA/cm2. Our results are in good agreement with those reported in the literature from experiments.

Description: The work presents comparisons of the flame stabilization characteristics of axisymmetric disk and 2D slender bluff-body burner configurations, operating with inlet mixture stratification, under ultralean conditions. A double cavity propane air premixer formed along three concentric disks, supplied with a radial equivalence ratio gradient the afterbody disk recirculation, where the first flame configuration is stabilized. Planar fuel injection along the center plane of the leading face of a slender square cylinder against the approach cross-flow results in a stratified flame configuration stabilized alongside the wake formation region in the second setup. Measurements of velocities, temperatures, and chemiluminescence, local extinction criteria, and large-eddy simulations are employed to examine a range of ultralean and close to extinction flame conditions. The variations of the reacting front disposition within these diverse reacting wake topologies, the effect of the successive suppression of heat release on the near flame region characteristics, and the reemergence of large-scale vortical activity on approach to lean blowoff (LBO) are investigated. The cross-correlation of the performance of these two popular flame holders that are at the opposite ends of current applications might offer helpful insights into more effective control measures for expanding the operational margin of a wider range of stabilization configurations.

Description: This review covers methods for modifying the structures of polysaccharides. The introduction of hydrophobic, acidic, basic, or other functionality into polysaccharide structures can alter the properties of materials based on these substances. The development of chemical methods to achieve this aim is an ongoing area of research that is expected to become more important as the emphasis on using renewable starting materials and sustainable processes increases in the future. The methods covered in this review include ester and ether formation using saccharide oxygen nucleophiles, including enzymatic reactions and aspects of regioselectivity; the introduction of heteroatomic nucleophiles into polysaccharide chains; the oxidation of polysaccharides, including oxidative glycol cleavage, chemical oxidation of primary alcohols to carboxylic acids, and enzymatic oxidation of primary alcohols to aldehydes; reactions of uronic-acid-based polysaccharides; nucleophilic reactions of the amines of chitosan; and the formation of unsaturated polysaccharide derivatives.

Description: The electroreduction behaviour and determination of cefoperazone using a hanging mercury drop electrode were investigated. Cyclic voltammograms of cefoperazone recorded in universal Britton-Robinson buffers pH 3–6 exhibited a single irreversible cathodic peak. The process was adsorption-controlled. Britton-Robinson buffer 0.04 M pH 4.0 was selected as a supporting electrolyte for quantitative purposes by differential pulse and square wave adsorptive cathodic stripping voltammetry. The experimental voltammetric conditions were optimized using Central Composite Face design. A reduction wave was seen in the range from −0.7 to −0.8 V. These voltammetric techniques were successfully validated as per ICH guidelines and applied for the determination of cefoperazone in its single and sulbactam containing powders for injection and statistically comparable to USP-HPLC. They were further extended to determine cefoperazone in spiked human urine with no matrix effect.

Description: The problem of exponential stability for the uncertain neutral Markovian jump systems with interval time-varying delays and nonlinear perturbations is investigated in this paper. This study starts from the corresponding nominal systems with known and partially unknown transition rates, respectively. By constructing a novel augmented Lyapunov functional which contains triple-integral terms and fully utilizes the bound of the delay, the delay-range-dependent and rate-dependent exponential stability criteria are developed by the Lyapunov theory, reciprocally convex lemma, and free weighting matrices. Then, the results about nominal systems are extended to the uncertain case. Finally, numerical examples are given to demonstrate the effectiveness of the proposed methods.

Description: The local fractional Schrödinger equations in the one-dimensional Cantorian system are investigated. The approximations solutions are obtained by using the local fractional series expansion method. The obtained solutions show that the present method is an efficient and simple tool for solving the linear partial differentiable equations within the local fractional derivative.

Description: An experiment of hydrogen preparation from steam-carbon reaction catalyzed by K2CO3 was carried out at 700°C, which was driven by the solar reaction system simulated with Xenon lamp. It can be found that the rate of reaction with catalyst is 10 times more than that without catalyst. However, for the catalytic reaction, there is no obvious change for the rate of hydrogen generation with catalyst content range from 10% to 20%. Besides, the conversion efficiency of solar energy to chemical energy is more than 13.1% over that by photovoltaic-electrolysis route. An analysis to the mechanism of catalytic steam-carbon reaction with K2CO3 is given, and an explanation to the nonbalanced [H2]/[CO + 2CO2] is presented, which is a phenomenon usually observed in experiment.

Description: Concentrations of Cd, Co, Pb, and Zn in riverbed sediments from six sampling stations along the Sungai Kilim, Langkawi, Malaysia, were determined by using the Teflon Bomb Digestion. From this study, the concentrations of heavy metals in riverbed sediments were found ranging between 6.10 and 8.87 μg/g dry weight for Co, 0.03 and 0.45 μg/g dry weight for Cd, 59.8 and 74.9 μg/g dry weight for Zn, and 1.06 and 11.69 μg/g dry weight for Pb. From the observation, these areas were polluted by domestic waste, aquaculture, and tourism activities. For clarity, enrichment factor index was used to determine the level of sediment contamination in the study area. From this study, the average EF value is a bit high for Cd () followed by Zn (), Pb (), and lastly, Co (). Based on the contamination categories, Cd was categorised as moderately enriched, while the rest of the metals studied were in deficient-to-minimally enriched by the anthropogenic sources.

Description: A catalytic adsorptive cathodic stripping voltammetric method on an improved bismuth film electrode (BiFE) for the determination of trace germanium in the presence of pyrogallol has been investigated. A well-defined and sensitive stripping peak of Ge(IV)-pyrogallol complex was observed at −0.79 V (versus SCE) in a 0.1 M acetate buffer solution (pH 4.8) at a deposition potential of −0.34 V. The reduction current is catalytically enhanced by adding KBrO3. The experimental variables and potential interference were studied. Compared with the BiFE plated in the solution prepared based on HAc-NaAc without trisodium citrate, the improved BiFE electrodeposited in the solution of HAc-NaAc containing trisodium citrate displayed a better electroanalytical performance for the determination of germanium(IV). Under the optimized conditions, the detection limit of Ge(IV) was 60 ng L−1, and the relative standard deviation (RSD) was 3.73% at 5 μg L−1 level (). This method was successfully applied to determine the total germanium in several Chinese herbal remedies.

Description: Changes of antioxidant properties of -lipoic acid (LA) after UV irradiation were studied. LA is the typical drug used in diabetic neuropathy. Quenching of free radicals is an important factor of therapy by using this substance. -Lipoic acid is exposed to UV irradiation during the storage. The aim of our studies was to examine the effect of UV irradiation on the interactions of LA with free radicals. The -lipoic acid was irradiated by UVA 315–400 nm light during 10 to 110 minutes by intervals of 10 minutes. The electron paramagnetic resonance spectroscopy was used as the experimental technique. The antioxidant properties of LA were spectroscopically confirmed. The strong effect of UV irradiation on interactions of -lipoic acid with free radicals was observed. It was pointed out that interactions of LA with free radicals decrease after its exposition on UV. The interactions of LA with free radicals were higher after the sample irradiation during 10 minutes than for the samples irradiated longer (20–110 minutes). The results are important for problems connected with photomedicine; they pointed out that -lipoic acid should not be stored on UV exposition. Application of electron paramagnetic resonance spectroscopy to characterize interactions of pharmacological substance with free radicals was confirmed.

Description: Copper antimony sulfide (CAS) is a relatively new class of sustainable absorber material, utilizing cost effective and abundant elements. Band gap engineered, modified CAS thin films were synthesized using electrodeposition and elevated temperature sulfurization approach. A testing analog of copper zinc antimony sulfide (CZAS) film-electrolyte interface was created in order to evaluate photoelectrochemical performance of the thin film of absorber materials. Eu3+/Eu2+ redox couple was selected for this purpose, based on its relative band offset with copper antimony sulfide. It was observed that zinc has a significant effect on CAS film properties. An enhanced photocurrent was observed for CAS film, modified with zinc addition. A detailed investigation has been carried out by changing stoichiometry, and corresponding surface and optical characterization results have been evaluated. A summary of favorable processing parameters of the films showing enhanced photoelectrochemical response is presented.

Description: Tidal influence and local morphology on circulation and salt transport are investigated in the Caeté river estuary, a well-mixed estuary along the north coast of Brazil. Velocity, temperature, and salinity data were collected in three different locations along the estuary’s main channel, over three single, 13 h tidal cycles. The aim of this study was to investigate the relationship between tidal distortion and salinity by using classical methods of comparison of three cross-channel circulation characteristics, as well as computation of salt flux and vertical mixing. Findings indicate a flood-ebb asymmetry in currents, due to the distinct funneling morphology of the estuary, with shallow marginal areas being dominant towards the estuary head, while both stratification and shear dominate near the estuary mouth. The tidal currents enhanced vertical diffusion in the mid- and lower reaches, explaining the prevailing weakly stratified conditions, while the dominant well-mixed conditions in the upper estuary are a result of a combination of stronger flood currents and negligible vertical saline gradient. The predominant downstream salt transport supports the conclusion that there is little accumulation of salt in the Caeté river estuary. In addition, findings indicate that tidal correlation and Stokes drift are important components in the upper estuary, while tidal correlation played an important role in the middle estuary, with fluvial discharge most important in the lower estuary.

Description: The present paper investigates the reliability analysis of industrial systems by using vague lambda-tau methodology in which information related to system components is uncertain and imprecise in nature. The uncertainties in the data are handled with the help of intuitionistic fuzzy set (IFS) theory rather than fuzzy set theory. Various reliability parameters are addressed for strengthening the analysis in terms of degree of acceptance and rejection of IFS. Performance as well as sensitivity analysis of the system parameter has been investigated for accessing the impact of taking wrong combinations on its performance. Finally results are compared with the existing traditional crisp and fuzzy methodologies results. The technique has been demonstrated through a case study of bleaching unit of a paper mill.

Description: A new stability-indicating reversed-phase high-performance thin-layer chromatographic (RP-HPTLC) method for densitometric analysis of thiocolchicoside was developed and validated. The chromatograms were developed using aluminum plates pre-coated with silica gel 60 RP-18 F254S as a stationary phase and methanol : water (70 : 30 ) as a mobile phase. The compact band for thiocolchicoside was observed at value of at an absorption wavelength of 377 nm. The linear regression data for the calibration plots () was found with respect to peak area in the concentration range of 100–600 ng per band. The limit of detection (LOD) and limit of quantification (LOQ) were 9.77 ng and 29.63 ng, respectively. The drug was exposed to acidic and alkaline hydrolysis, oxidation, photo degradation, and dry heat conditions. The peaks of degradation products were well-resolved from the peak of the standard drug with significantly different values. Statistical analysis proved that the established RP-HPTLC method is reproducible, selective, and accurate for the determination of thiocolchicoside in its formulations. The method can effectively separate the drug from its degradation products, and it can be considered as stability-indicating assay.

Description: In CdS/CdTe solar cells, chemical interdiffusion at the interface gives rise to the formation of an interlayer of the ternary compound . In this work, we evaluate the effects of this interlayer in CdS/CdTe photovoltaic cells in order to improve theoretical results describing experimental - (capacitance versus voltage) characteristics. We extended our previous theoretical methodology developed on the basis of three cardinal equations (Castillo-Alvarado et al., 2010). The present results provide a better fit to experimental data obtained from CdS/CdTe solar cells grown in our laboratory by the chemical bath deposition (for CdS film) and the close-spaced vapor transport (for CdTe film) techniques.

Description: A relationship between sea surface temperature (SST) and surface nitrate concentrations has been obtained for the first time based on in situ datasets retrieved from U.S. JGOFS (1991–96) and Indian cruises (2000–2006) in the Arabian Sea, Bay of Bengal and Indian Ocean region around the southern Indian tip. The dataset includes 1537 points. A sigmoid relationship obtained with

Description: The ice floe speed variations were monitored at the research camp North Pole 35 established on the Arctic ice pack in 2008. A three-month time series of measured speed values was used for determining changes in the kinetic energy of the drifting ice floe. The constructed energy distributions were analyzed by methods of nonextensive statistical mechanics based on the Tsallis statistics for open nonequilibrium systems, such as tectonic formations and drifting sea ice. The nonextensivity means the nonadditivity of externally induced energy changes in multicomponent systems due to dynamic interrelation of components having no structural links. The Tsallis formalism gives one an opportunity to assess the correlation between ice floe motions through a specific parameter, the so-called parameter of nonextensivity. This formalistic assessment of the actual state of drifting pack allows one to forecast some important trends in sea ice behavior, because the level of correlated dynamics determines conditions for extended mechanical perturbations in ice pack. In this work, we revealed temporal fluctuations of the parameter of nonextensivity and observed its maximum value before a large-scale sea ice fragmentation (faulting) of consolidated sea ice. The correlation was not detected in fragmented sea ice where long-range interactions are weakened.

Description: Symbiotic diatom-diazotrophic cyanobacteria association (DDA) of Rhizosolenia hebetata and Rhizosolenia formosa with endosymbiotic cyanobacteria Richelia intracellularis was noticed and documented for the first time during a bloom of the cyanobacterium Trichodesmium erythraeum in the oligotrophic shelf waters along Kochi and Mangalore transects, southeastern Arabian Sea (SEAS), during spring intermonsoon (April 2012). Although the host is frequently seen, the symbiont is rarely reported in the Indian EEZ. The presence of nitrogen-fixing symbiotic association of Rhizosolenia-Richelia along with Trichodesmium erythraeum highlights the significance of DDAs on the nutrient and energy budgets of phytoplankton in the oligotrophic environments of the Arabian Sea during spring intermonsoon.

Description: Recent studies on the diazotrophic cyanobacterium Trichodesmium showed that increasing CO2 partial pressure (pCO2) enhances N2 fixation and growth. We studied the in situ and satellite-derived environmental parameters within and outside a Trichodesmium bloom in the western coastal Bay of Bengal (BoB) during the spring intermonsoon 2009. Here we show that the single most important nitrogen fixer in today’s ocean, Trichodesmium erythraeum, is strongly abundant in high (≥300 μatm) pCO2 concentrations. N : P ratios almost doubled (~10) at high pCO2 region. This could enhance the productivity of N-limited BoB and increase the biological carbon sequestration. We also report presence of an oxygen minimum zone at Thamnapatnam. Earlier studies have been carried out using lab cultures, showing the increase in growth rate of T. erythraeum under elevated pCO2 conditions, but to our knowledge, this study is the first to report that in natural environment also T. erythraeum prefers blooming in high pCO2 concentrations. The observed CO2 sensitivity of T. erythraeum could thereby provide a strong negative feedback to rising atmospheric CO2 but would also drive towards phosphorus limitation in a future high CO2 world.

Description: In a silicon wafer-based photovoltaic (PV) module, significant power is lost due to current transport through the ribbons interconnecting neighbour cells. Using halved cells in PV modules is an effective method to reduce the resistive power loss which has already been applied by some major PV manufacturers (Mitsubishi, BP Solar) in their commercial available PV modules. As a consequence, quantitative analysis of PV modules using halved cells is needed. In this paper we investigate theoretically and experimentally the difference between modules made with halved and full-size solar cells. Theoretically, we find an improvement in fill factor of 1.8% absolute and output power of 90 mW for the halved cell minimodule. Experimentally, we find an improvement in fill factor of 1.3% absolute and output power of 60 mW for the halved cell module. Also, we investigate theoretically how this effect confers to the case of large-size modules. It is found that the performance increment of halved cell PV modules is even higher for high-efficiency solar cells. After that, the resistive loss of large-size modules with different interconnection schemes is analysed. Finally, factors influencing the performance and cost of industrial halved cell PV modules are discussed.

Description: In three-phase photovoltaic (PV) system, three-phase filter inductors are important part for the output electrical power quality. The comparison analyses of three-phase discrete filter inductors and two kinds of three-phase integrated filter inductors in three-phase PV inverter are proposed. Firstly, the three-phase PV inverter operation with discrete filter inductors is analyzed, and the design of discrete filter inductors is given; then operation of the three-phase PV inverter with three-phase integrated five-limb magnetic core filter inductors is analyzed, the design of integrated filter inductors with five-limb magnetic core is given, then the operation of three-phase PV inverter with three-phase integrated three-limb magnetic core filter inductors is analyzed, and the design of integrated filter inductors with three limbs magnetic core is given. The conclusion of comparison between three-phase discrete filter inductors and two kinds of three-phase integrated filter inductors is done; it means that the three-phase discrete filter inductors can achieve better output electrical power quality with lower power density and three-phase integrated filter inductors can achieve higher power density with lower output electrical power quality. Finally, the experiment results are given to compare the volume and filter effect of three kinds of filter inductors in three-phase PV inverter.

Description: A classical issue in many applied fields is to obtain an approximating surface to a given set of data points. This problem arises in Computer-Aided Design and Manufacturing (CAD/CAM), virtual reality, medical imaging, computer graphics, computer animation, and many others. Very often, the preferred approximating surface is polynomial, usually described in parametric form. This leads to the problem of determining suitable parametric values for the data points, the so-called surface parameterization. In real-world settings, data points are generally irregularly sampled and subjected to measurement noise, leading to a very difficult nonlinear continuous optimization problem, unsolvable with standard optimization techniques. This paper solves the parameterization problem for polynomial Bézier surfaces by applying the firefly algorithm, a powerful nature-inspired metaheuristic algorithm introduced recently to address difficult optimization problems. The method has been successfully applied to some illustrative examples of open and closed surfaces, including shapes with singularities. Our results show that the method performs very well, being able to yield the best approximating surface with a high degree of accuracy.

Description: The tension between the meaning of causality in science and law or public policy is well-known; however, defendants in product liability cases or industries that might be affected by a government regulation may try to convince the factfinder to require evidence of a causal relationship that meets the standards of science. From the perspective of public health, however, people may be exposed unnecessarily to a health risk during the time period between the establishment of reasonably strong evidence of a causal relationship and the overwhelming evidence required for scientific causality. The Bayesian paradigm enables one to update information from epidemiologic studies as they accumulate, providing estimates of the probability that the relative risk of a particular harm from exposure exceeds a threshold value, e.g. 2.0 or 4.0 that is sufficient to meet the preponderance of the evidence standard or to support a health initiative. In order to diminish the role of the initial prior distribution, which may be quite subjective, the first case-control study or an analysis of adverse event and case reports is used to determine two prior distributions. One is the most favourable to the defendant, or industry that might be regulated, which is consistent with the previous data. The other is centred on or near the estimated relative risk from the first study. The method is applied to the studies that linked aspirin use to Reye syndrome and demonstrates that the evidence of a causal association was sufficiently strong in 1982, when the Food and Drug Administration first proposed that the public be warned of the risk, to support the regulation. Thus, lives would have been saved had the warning been given at the end of 1982 rather than in early 1985.

Description: In law, inferences of causation are sometimes made through a structured process in which multiple participants play various roles, and make decisions concerning various logical components of the overall inference (such as legal rules, policy objectives, presumptions, evidence, burdens of proof and findings of fact). This article illustrates such a process using empirical research into compensation decisions in the USA for injuries allegedly caused by vaccinations. Empirical research into actual legal processes is essential, in order to discover how various players approach their sub-tasks of decision-making. It also provides insights for areas outside of law, such as non-monotonic logic, cognitive science, sociology and artificial intelligence.

Description: Situations of causal factual uncertainty are relatively common in law. The problems and difficulties regarding ‘factual causation’ in law point to the need of ‘evidence’ and ‘proof’ models that are adequate and capable to accommodate the tests and methodologies used to explain and demonstrate it in a legal context. Given the configuration of the situations of causal factual uncertainty and the available ‘evidence’ and ‘proof’ models, I argue that it is justified to use an ‘argumentative-narrative’ model for ‘proving causation’ in law. However, considering that each model of ‘evidence’ and ‘proof’ reveals a different kind of ‘rationality’ that can still be viewed in different ways, I also argue that we must try to match the perspective we have on the ‘rationality’ behind the chosen model of ‘evidence’ and ‘proof’ with the ‘rationality’ underlying ‘causation’ in law.

Description: At least in some cases, the values confronted in legal decision-making appear to be incommensurable. Some legal theorists resist incommensurability because they fear that this presents an overwhelming obstacle to rational decision-making. By offering a close analysis of proportionality and, more particularly, measures of proportional value satisfaction, I show that this fear is unfounded. Comparative measures of proportional value satisfaction do not require the values to be commensurable. However, assuming incommensurability presents us with the problem of public significance in the proportional satisfaction of values. When two values are commensurable, this public significance is provided by the mediating effects of the overarching third value that provides the common measure of the values. However, when this common measure is removed, then the public significance of value satisfaction must be otherwise achieved. This is why I propose an equal proportional value satisfaction as the most appropriate proportionality maximand. Under equal proportional value satisfaction, the proportional satisfaction of any one value has significance for each and every other value. This kind of public significance is interpersonal rather than impersonal (or second-personal rather than third-personal). The article then shows that the legal process that is most appropriate to equal proportionality is a process that implements defeasible legal rules.

Description: In order to allocate the risk between parties in legal adjudication, we use evidentiary techniques with the main device among them being the standard of proof (SoP). The traditional view holds the grade of probability to be the parameter that shifts when moving to different standards. However, as soon as we dig slightly deeper, an incoherent picture is being revealed. In this article, I challenge the accepted view and try to show that it faces insurmountable problems concerning the rationality, the grammatical consistency and the impact of the SoP for the acceptability of verdicts. At the end of the article, I shortly discuss the theory of epistemological contextualism and propose a framework that allows rational distinctions to be drawn between different standards of proof. In the second part of this project (forthcoming), I will defend a contextualist view according to which shifting parameter is not the grade of (aleatory) probability, but instead the Set of Epistemic Defeaters in play.

Description: This paper proposes a partial refactorization for faster nonlinear analysis based on sparse matrix solution, which is nowadays the default solution choice in finite element analysis and can solve finite element models up to millions degrees of freedom. Among various fill-in’s reducing strategies for sparse matrix solution, the graph partition is in general the best in terms of resultant fill-ins and floating-point operations and furthermore produces a particular graph of sparse matrix that prevents local change of entries from wide spreading in factorization. Based on this feature, an explicit partial triangular refactorization with local change is efficiently constructed with limited additional storage requirement in row-sparse storage scheme. The partial refactorization of the changed stiffness matrix inherits a big percentage of the original factor and is carried out only on partial factor entries. The proposed method provides a new possibility for faster nonlinear analysis and is mainly suitable for material nonlinear problems and optimization problems. Compared to full factorization, it can significantly reduce the factorization time and can make nonlinear analysis more efficient.

Description: Prediction of RNA structure is a useful process for creating new drugs and understanding genetic diseases. In this paper, we proposed a particle swarm optimization (PSO) and ant colony optimization (ACO) based framework (PAF) for RNA secondary structure prediction. PAF consists of crucial stem searching (CSS) and global sequence building (GSB). In CSS, a modified ACO (MACO) is used to search the crucial stems, and then a set of stems are generated. In GSB, we used a modified PSO (MPSO) to construct all the stems in one sequence. We evaluated the performance of PAF on ten sequences, which have length from 122 to 1494. We also compared the performance of PAF with the results obtained from six existing well-known methods, SARNA-Predict, RnaPredict, ACRNA, PSOfold, IPSO, and mfold. The comparison results show that PAF could not only predict structures with higher accuracy rate but also find crucial stems.

Description: The problem of robust fault tolerant control for continuous-time fractional-order (FO) systems with interval parameters and sensor faults of has been investigated. By establishing sensor fault model and state observer, an observer-based FO output feedback controller is developed such that the closed-loop FO system is asymptotically stable, not only when all sensor components are working well, but also in the presence of sensor components failures. Finally, numerical simulation examples are given to illustrate the application of the proposed design method.

Description: The rural/remote IMPROVE network (Interagency Monitoring of Protected Visual Environments) and the Environmental Protection Agency's urban Chemical Speciation Network have measured PM2.5 organic (OC) and elemental carbon (EC) since 1989 and 2000, respectively. We aggregated OC and EC data from 2007 to 2010 at over 300 sites from both networks in order to characterize the spatial and seasonal patterns in rural and urban carbonaceous aerosols. The spatial extent of OC and EC was more regional in the eastern United States relative to more localized concentrations in the West. The highest urban impacts of OC and EC relative to background concentrations occurred in the West during fall and winter. Urban and rural carbonaceous aerosols experienced a large (although opposite) range in seasonality in the West compared to a much lower seasonal variability in the East. Long-term (1990–2010) trend analyses indicated a widespread decrease in rural TC (TC = OC + EC) across the country, with positive, though insignificant, trends in the summer and fall in the West. Short-term trends indicated that urban and rural TC concentrations have both decreased since 2000, with the strongest and more spatially homogeneous urban and rural trends in the West relative to the East.

Description: The Doppler velocity dealiasing technique based on alias-robust VAD and variational (AR-Var) analyses developed at the National Severe Storms Laboratory for radar data quality control and assimilation is further improved in its two-step procedures: the reference check in the first step and the continuity check in the second step. In the first step, the alias-robust variational analysis is modified adaptively and used in place of the alias-robust velocity-azimuth display (VAD) analysis for all scan modes (rather than solely the WSR-88D volume coverage pattern 31 with the Nyquist velocity reduced below 12 m s−1 and the TDWR Mod80 with reduced below 15 m s−1), so more raw data can pass the stringent threshold conditions used by the reference check in the first step. This improves the dealiased data coverage without false dealiasing to better satisfy the high data quality standard required by radar data assimilation. In the second step, new procedures are designed and added to the continuity check to increase the dealiased data coverage over storm-scale areas threatened by intense mesocyclones and their generated tornados. The performances of the improved dealiasing technique versus the existing techniques are exemplified by the results obtained for tornadic storms scanned by the operational KTLX radar in Oklahoma.

Description: There is much interest in using high-throughput DNA sequencing methodology to monitor microorganisms, complex plant and animal communities. However, there are experimental and analytical issues to consider before applying a sequencing technology, which was originally developed for genome projects, to ecological projects. Many of these issues have been highlighted by recent microbial studies. Understanding how high-throughput sequencing is best implemented is important for the interpretation of recent results and the success of future applications. Addressing complex biological questions with metagenomics requires the interaction of researchers who bring different skill sets to problem solving. Educators can help by nurturing a collaborative interdisciplinary approach to genome science, which is essential for effective problem solving. Educators are in a position to help students, teachers, the public and policy makers interpret the new knowledge that metagenomics brings. To do this, they need to understand, not only the excitement of the science but also the pitfalls and shortcomings of methodology and research designs. We review these issues and some of the research directions that are helping to move the field forward.

Description: We believe that undergraduate biology students must acquire a foundational background in computing including how to formulate a computational problem; develop an algorithmic solution; implement their solution in software and then test, document and use their code to explore biological phenomena. Moreover, by learning these skills in the first year, students acquire a powerful tool set that they can use and build on throughout their studies. To address this need, we have developed a first-year undergraduate course that teaches students the foundations of computational thinking and programming in the context of problems in biology. This article describes the structure and content of the course and summarizes assessment data on both affective and learning outcomes.

Description: Bioinformatics is an integral part of modern life sciences. It has revolutionized and redefined how research is carried out and has had an enormous impact on biotechnology, medicine, agriculture and related areas. Yet, it is only rarely integrated into high school teaching and learning programs, playing almost no role in preparing the next generation of information-oriented citizens. Here, we describe the design principles of bioinformatics learning environments, including our own, that are aimed at introducing bioinformatics into senior high school curricula through engaging learners in scientifically authentic inquiry activities. We discuss the bioinformatics-related benefits and challenges that high school teachers and students face in the course of the implementation process, in light of previous studies and our own experience. Based on these lessons, we present a new approach for characterizing the questions embedded in bioinformatics teaching and learning units, based on three criteria: the type of domain-specific knowledge required to answer each question (declarative knowledge, procedural knowledge, strategic knowledge, situational knowledge), the scientific approach from which each question stems (biological, bioinformatics, a combination of the two) and the associated cognitive process dimension (remember, understand, apply, analyze, evaluate, create). We demonstrate the feasibility of this approach using a learning environment, which we developed for the high school level, and suggest some of its implications. This review sheds light on unique and critical characteristics related to broader integration of bioinformatics in secondary education, which are also relevant to the undergraduate level, and especially on curriculum design, development of suitable learning environments and teaching and learning processes.

Description: The aim of this paper is to study the relations between the Hausdorff dimensions of k -quasilines and the theory of extremal quasiconformal mappings. We show that there is an open and dense subset (Strebel points) of the universal Teichmüller space T (H) such that, for every [ f ] in the set, the Hausdorff dimension of the k -quasiline determined by [ f ] is strictly less than 1 + k 2 . We also show that there are some points [ f ] != [id] outside the open and dense set in the universal Teichmüller space such that the Hausdorff dimension of the quasiline determined by [ f ] is 1. Moreover, some results on the Hausdorff dimensions of the quasilines varying in the asymptotic Teichmüller space are also obtained.

Description: Next-generation sequencing (NGS) is increasingly being adopted as the backbone of biomedical research. With the commercialization of various affordable desktop sequencers, NGS will be reached by increasing numbers of cellular and molecular biologists, necessitating community consensus on bioinformatics protocols to tackle the exponential increase in quantity of sequence data. The current resources for NGS informatics are extremely fragmented. Finding a centralized synthesis is difficult. A multitude of tools exist for NGS data analysis; however, none of these satisfies all possible uses and needs. This gap in functionality could be filled by integrating different methods in customized pipelines, an approach helped by the open-source nature of many NGS programmes. Drawing from community spirit and with the use of the Wikipedia framework, we have initiated a collaborative NGS resource: The NGS WikiBook. We have collected a sufficient amount of text to incentivize a broader community to contribute to it. Users can search, browse, edit and create new content, so as to facilitate self-learning and feedback to the community. The overall structure and style for this dynamic material is designed for the bench biologists and non-bioinformaticians. The flexibility of online material allows the readers to ignore details in a first read, yet have immediate access to the information they need. Each chapter comes with practical exercises so readers may familiarize themselves with each step. The NGS WikiBook aims to create a collective laboratory book and protocol that explains the key concepts and describes best practices in this fast-evolving field.

Description: A new uniqueness result for a general n th order differential equation is obtained. We show that some previous results follow immediately from our theorem.

Description: Consider a discrete uniformly elliptic divergence form equation on the d ≥3 dimensional lattice Z d with random coefficients. In Conlon and Spencer [ Trans. Amer. Math. Soc. , http://www.math.lsa.umich.edu/~conlon/paper/hom10.pdf ], rate of convergence results in homogenization and estimates on the difference between the averaged Green's function and the homogenized Green's function for random environments which satisfy a Poincaré inequality were obtained. Here, these results are extended to certain environments in which correlations can have arbitrarily small power law decay. These environments are simply related via a convolution to environments which do satisfy a Poincaré inequality.

Description: In this paper, we prove that, for any a , M N with ( a , M ) = 1, there are infinitely many Carmichael numbers m such that m a mod M .

Description: We give a topological analogue for openness of a criterion for flatness that originates with Auslander. Over a normal base of dimension n , failure of openness is detected by a vertical component in the n th fibred power of the morphism.

Description: Investigated are regular maps from real algebraic varieties into real Fermat varieties. It is proved that under some natural assumptions, all such maps are null homotopic.

Description: Let ( M , g ) be a complete non-compact Riemannian manifold. We consider operators of the form g + V , where g is the non-negative Laplacian associated with the metric g , and V a locally integrable function. Let be a Riemannian covering, with Laplacian g and potential . If the operator + V is non-negative on ( M , g ), then the operator is non-negative on . In this note, we show that the converse statement is true provided that is a co-amenable subgroup of 1 ( M ).

Description: Peak interpolation is concerned with a foundational kind of mathematical task: building functions in a fixed algebra A , which have prescribed values or behaviour on a fixed closed subset (or on several disjoint subsets). In this paper, we do the same but now A is an algebra of operators on a Hilbert space. We briefly survey this noncommutative peak interpolation , which we have studied with coauthors in a long series of papers, and whose basic theory now appears to be approaching its culmination. This programme developed from, and is based partly on, theorems of Hay and Read whose proofs were spectacular, but therefore inaccessible to an uncommitted reader. We give short proofs of these results, using recent progress in noncommutative peak interpolation, and conversely give examples of the use of these theorems in peak interpolation. For example, we prove a useful new noncommutative peak interpolation theorem.

Description: We show how a parameterized family of maps of the spine of a manifold can be used to construct a family of homeomorphisms of the ambient manifold which have the inverse limits of the spine maps as global attractors. We describe applications to unimodal families of interval maps, to rotation sets, and to the standard family of circle maps.

Description: For every prime p , we give infinitely many examples of torsors under abelian varieties over Q that are locally trivial but not divisible by p in the Weil–Châtelet group. We also give an example of a locally trivial torsor under an elliptic curve over Q that is not divisible by 4 in the Weil–Châtelet group. This gives a negative answer to a question of Cassels.

Description: We show that at least of the zeros of the Riemann zeta-function are simple, assuming the Riemann hypothesis. This was previously established by Conrey, Ghosh and Gonek [ Proc. London Math. Soc. 76 (1998) 497–522] under the additional assumption of the generalized Lindelöf hypothesis. We are able to remove this hypothesis by careful use of the generalized Vaughan identity.

Description: We construct an infinite family of hyperbolic, homologically thin knots that are not quasi-alternating. To establish the latter, we argue that the branched double-cover of each knot in the family does not bound a negative-definite 4-manifold with trivial first homology and bounded second Betti number. This fact depends in turn on information from the correction terms in Heegaard Floer homology, which we establish by way of a relationship to, and calculation of, the Turaev torsion.

Description: We observe that E -resultant of a very ample rank 2 vector bundle E on a real projective curve (with no real points) is nonnegative when restricted to the space of real sections. Moreover, we show that if E has a section vanishing at exactly two points and the degree d of E satisfies d ( d – 6) ≥ 4( g – 1), then this polynomial cannot be written as a sum of squares.

Description: Let G be one of the Ricci-flat holonomy groups SU( n ), Sp( n ), Spin(7) or G 2 , and M a compact manifold of dimension 2 n , 4 n , 8 or 7, respectively. We prove that the natural map from the moduli space of torsion-free G -structures on M to the moduli space of Ricci-flat metrics is open, and that the image is a smooth manifold. For the exceptional cases G = Spin(7) and G 2 , we extend the result to asymptotically cylindrical manifolds.

Description: We improve the results of Booker and Krishnamurthy ( Compos. Math. 147 (2011) 669–715) by allowing restricted sets of poles among the unramified twists. This allows for a clean statement of the GL(2) converse theorem which includes all cases of Eisenstein series.

Description: Let G be a solvable subgroup of the automorphism group Aut( X ) of a compact Kähler manifold X of complex dimension n , and let N ( G ) be the normal subgroup of G consisting of elements with null entropy. Let us denote by G * the image of G under the natural map from Aut( X ) to GL( V , R ), where V is the Dolbeault cohomology group H 1, 1 ( X , R ). Assume that the Zariski closure of G * in GL( V C ) is connected. The main aim of this paper is to show that, when the rank r ( G ) of the quotient group G / N ( G ) is equal to n – 1 and the identity component of Aut( X ) is trivial, then the normal subgroup N ( G ) of G is finite. This affirmatively answers a question in Invent. Math. posed by D.-Q. Zhang.

Description: It is widely accepted that tumorigenesis is a multistep process characterized by the sequential accumulation of genetic alterations. However, the molecular basis of genomic instability in cancer is still partially understood. The observation that hereditary cancers are often characterized by mutations in DNA repair and checkpoint genes suggests that accumulation of DNA damage is a major contributor to the oncogenic transformation. It is therefore of great interest to identify all the cellular pathways that contribute to the response to DNA damage. Recently, RNA processing has emerged as a novel pathway that may contribute to the maintenance of genome stability. In this review, we illustrate several different mechanisms through which pre-mRNA splicing and genomic stability can influence each other. We specifically focus on the role of splicing factors in the DNA damage response and describe how, in turn, activation of the DDR can influence the activity of splicing factors.

Description: The components and claddings of low-rise buildings are usually destroyed first during typhoon disasters in coastal areas. Roof accessory structures can change the flow pattern on the roof, thus effectively reducing the wind load on the roof surface and the damage to the low-rise buildings. Three types of aerodynamic mitigation plates, that is, (1) 0.3 m high full-length roof-edge plate, (2) 0.3 m high and 0.5 m + 0.5 m long roof-corner plate, and (3) discrete roof-edge plates with different spaces (which can be used as advertisement boards), are studied on the basis of the field measurement results under roof pitches of 10° and 18.4°. By comparing the results of the roof with and without constructed plates, it is implied that the three types of plates can affect the formation of conical vortexes and can significantly reduce the mean and fluctuating pressure coefficients in the windward corner. Compared with the constructed plate, the roof ridge has a larger influence on the wind loads on leeward roof.

Description: Composite silicon dioxide-titanium dioxide (SiO2-TiO2) films are deposited on a large area of 15.6 × 15.6 cm2 textured multicrystalline silicon solar cells to increase the incident light trapped within the device. For further improvement of the antireflective coatings (ARCs) quality, dimethylformamide (DMF) solution is added to the original SiO2-TiO2 solutions. DMF solution solves the cracking problem, thus effectively decreasing reflectance as well as surface recombination. The ARCs prepared by sol-gel process and plasma-enhanced chemical vapor deposition (PECVD) on multicrystalline silicon substrate are compared. The average efficiency of the devices with improved sol-gel ARCs is 16.3%, only 0.5% lower than that of devices with PECVD ARCs (16.8%). However, from equipment depreciation point of view (the expiration date of equipment is generally considered as 5 years), the running cost (USD/watt) of sol-gel technique is 80% lower than that of PECVD method for the first five years and 66% lower than that of PECVD method from the start of the sixth year. This result proves that sol-gel-deposited ARCs process has potential applications in manufacturing low-cost, large-area solar cells.

Description: We study the lattice dynamical system of a nonlinear Boussinesq equation. We first verify the Lipschitz continuity of the continuous semigroup associated with the system. Then, we provide an estimation of the tail of the difference between two solutions of the system. Finally, we obtain the existence of an exponential attractor of the system.

Description: A novel scheme for fault-tolerant control is proposed in this paper, in which model reference adaptive control method is incorporated with control allocation to cope with simultaneous actuator failures, input saturation, and model mismatch in the flight system. In order to reduce performance degradation caused by actuator failures, the proposed scheme redistributes the control signal to healthy actuators and updates the weighting matrix based on actuator effectiveness. Because of saturation errors resulting from actuator constraints and model mismatch caused by abnormal changes in the system, the original reference model may not be appropriate. Under this circumstance, an adaptive reference model which can also provide satisfactory performance is designed. Simulations of a flight control example are given to illustrate the effectiveness of the proposed scheme.

Description: A virtual channels scheduling algorithm with broad applicability based on movable boundary is proposed. According to the types of date sources, transmission time slots are divided into synchronous ones and asynchronous ones with a movable boundary between them. During the synchronous time slots, the virtual channels are scheduled with a polling algorithm; during the asynchronous time slots, the virtual channels are scheduled with an algorithm based on virtual channel urgency and frame urgency. If there are no valid frames in the corresponding VC at a certain synchronous time slot, a frame of the other synchronous VCs or asynchronous VCs will be transmitted through the physical channel. Only when there are no valid frames in all VCs would an idle frame be generated and transmitted. Experiments show that the proposed algorithm yields much lower scheduling delay and higher channel utilization ratio than those based on unmovable boundary or virtual channel urgency in many kinds of sources. Therefore, broad applicability can be achieved by the proposed algorithm.

Description: Self-localization is a basic skill for mobile robots in the dynamic environments. It is usually modeled as a state estimation problem for nonlinear system with non-Gaussian noise and needs the real-time processing. Unscented particle filter (UPF) can handle the state estimation problem for nonlinear system with non-Gaussian noise; however the computation of UPF is very high. In order to reduce the computation cost of UPF and meanwhile maintain the accuracy, we propose an adaptive unscented particle filter (AUPF) algorithm through relative entropy. AUPF can adaptively adjust the number of particles during filtering to reduce the necessary computation and hence improve the real-time capability of UPF. In AUPF, the relative entropy is used to measure the distance between the empirical distribution and the true posterior distribution. The least number of particles for the next step is then decided according to the relative entropy. In order to offset the difference between the proposal distribution, and the true distribution the least number is adjusted thereafter. The ideal performance of AUPF in real robot self-localization is demonstrated.

Description: With the water and soil conservation forests of Robinia pseudoacacia in the Malian beach of Hongqi farm, Ji County, Shanxi province, as the research object, this study estimated the potential evapotranspiration in the open space outside the forest and at the heights of 3 m, 6 m, and 10 m in the forests with the climate data during 2011-2012 and the upgraded Penman-Monteith formula; then, this study explored the microclimate characteristics inside and outside the Robinia pseudoacacia forest and thereafter revealed the vertical variation rules of potential evapotranspiration of Robinia pseudoacacia. The results indicate that the air temperature, relative humidity, wind speed, and potential evapotranspiration at different heights above the ground surface showed similar changing trends, but with some variation during different periods. In addition, the weather also had impacts on the potential evapotranspiration. In April, July, and October, the change of potential evapotranspiration of the Robinia pseudoacacia forests showed a bimodal curve in the sunny days and rainy days, while it showed a single-peak curve with quite small fluctuation in the rainy days. However, it showed a single-peak pattern even in the sunny days in January, and it showed no fluctuation in the snowy days in January.

Description: Cooperative communications that take advantage of the broadcasting nature of wireless environments can help to increase system throughput in wireless ad hoc networks. However, the promised throughput might be lost in presence of the error transmission and the interference caused by relay transmission in cooperative communication. In this paper, we introduced the relay selection schemes that can control the interference at the relay to prevent the relay that may harm other pairs. Then, we proposed the throughput-optimal scheduling that takes into account error probability in decision and maximizes throughput, that is, the amount of packets transmitted without error in network. In addition, we derive a simple and lightweight framework to implement the proposed policy in distributed manner. The simulation results show that the proposed scheduling policy outperforms the noncooperative policy and multihop relay policy.

Description: This paper is the second in a series of papers considering symmetry properties of bosonic quantum systems over 2D graphs, with continuous spins, in the spirit of the Mermin-Wagner theorem. In the model considered here the phase space of a single spin is where is a -dimensional unit torus with a flat metric. The phase space of spins is , the subspace of formed by functions symmetric under the permutations of the arguments. The Fock space yields the phase space of a system of a varying (but finite) number of particles. We associate a space with each vertex of a graph satisfying a special bidimensionality property. (Physically, vertex represents a heavy “atom” or “ion” that does not move but attracts a number of “light” particles.) The kinetic energy part of the Hamiltonian includes (i) , the minus a half of the Laplace operator on , responsible for the motion of a particle while “trapped” by a given atom, and (ii) an integral term describing possible “jumps” where a particle may join another atom. The potential part is an operator of multiplication by a function (the potential energy of a classical configuration) which is a sum of (a) one-body potentials , , describing a field generated by a heavy atom, (b) two-body potentials , , showing the interaction between pairs of particles belonging to the same atom, and (c) two-body potentials , , scaled along the graph distance between vertices , which gives the interaction between particles belonging to different atoms. The system under consideration can be considered as a generalized (bosonic) Hubbard model. We assume that a connected Lie group acts on , represented by a Euclidean space or torus of dimension , preserving the metric and the volume in . Furthermore, we suppose that the potentials , , and are -invariant. The result of the paper is that any (appropriately defined) Gibbs states generated by the above Hamiltonian is -invariant, provided that the thermodynamic variables (the fugacity and the inverse temperature ) satisfy a certain restriction. The definition of a Gibbs state (and its analysis) is based on the Feynman-Kac representation for the density matrices.

Description: The dihedral angle formed at junctions between two plagioclase grains and a grain of augite is only very rarely in textural equilibrium in gabbros from kilometre-scale crustal layered intrusions. The median of a population of these disequilibrium angles, cpp , varies systematically within a single layered intrusion, remaining constant over large stretches of stratigraphy with significant increases and decreases associated with the addition or reduction respectively of the number of phases on the liquidus of the bulk magma. The stepwise changes in cpp are present in the Upper Zone of the Bushveld Complex, the Megacyclic Unit I of the Sept Iles Intrusion, and the Layered Series of the Skaergaard intrusion. The plagioclase-bearing cumulates of Rum have a bimodal distribution of cpp , dependent on whether the cumulus assemblage includes clinopyroxene. The presence of the stepwise changes is independent of the order of arrival of cumulus phases and of the composition of either the cumulus phases or the inferred composition of the interstitial liquid. The only parameter that behaves in an exactly analogous manner to cpp is the rate of change in enthalpy with temperature ( H / T ) during crystallization. Both H / T and cpp increase with the addition of a liquidus phase, and decrease with the removal of a liquidus phase. The replacement of one phase by another has little effect on H / T and no discernible effect on cpp . An increase of H / T results in an increase in the fraction of the total enthalpy budget that is the latent heat of crystallization (the fractional latent heat). It also increases the mass crystallized in each incremental temperature drop (the crystal productivity). These increases of both fractional latent heat and crystal productivity are likely to cause an increase in the time taken to form three-grain junctions in the mush via thermal buffering of a thickened mushy layer. We suggest these are the underlying causes of stepwise increases in cpp . Stepwise changes in the geometry of three-grain junctions in fully solidified gabbros thus provide a clear microstructural marker for the progress of fractionation down the liquid line of descent in layered intrusions.

Description: High-resolution sampling in monogenetic fields has the potential to reveal fine-scale heterogeneity of the mantle, a feature that may be overwhelmed by larger fluxes of magma, or missed by under-sampling. The Quaternary Auckland Volcanic Field (AVF) in northern New Zealand is a basaltic field of 51 small-volume volcanic centres, and is one of the best-sampled examples of a monogenetic volcanic field. We present data for 12 centres in the volcanic field. These show the large compositional variations between volcanoes as well as through single eruptive sequences. Whole-rock compositions range from subalkaline basalt in the larger centres, through alkali basalt to nephelinite in the smallest centres. Fractional crystallization has had a limited effect in many of the centres, but high-pressure clinopyroxene crystallization may have occurred in others. Three end-members are observed in Pb isotope space, indicating that distinct mantle source components are involved in the petrogenesis of the magmas. Whole-rock multi-element patterns show that the larger centres have prominent positive Sr anomalies and lack K anomalies, whereas the smaller centres have prominent negative K anomalies and lack Sr anomalies. The melting parameters and compositions of the sources involved are modelled using trace element ratios and multi-element patterns, and three components are characterized: (1) fertile peridotite with a Pb-isotope composition similar to Pacific mid-ocean ridge basalt; (2) eclogite domains with a HIMU-like isotope composition dispersed within the fertile peridotite; (3) slightly depleted subduction-metasomatized peridotitic lithospheric mantle (containing c . 3% subduction fluids). Modelling shows that melting in the AVF begins in garnet-bearing fertile asthenosphere (with preferential melting of eclogite domains) and that melts are variably diluted by melts of the lithospheric source. The U–Th isotope compositions of the end-members in the AVF show 230 Th excess [( 230 Th/ 232 Th) ratios of 1·11–1·38], with the samples of lower ( 230 Th/ 232 Th) exhibiting higher ( 238 U/ 232 Th), which we attribute to the dilution effect of the melts from the lithospheric mantle source. Modelling reveals a correlation between melting in the asthenosphere, the degree of melting and incorporation of the metasomatized lithospheric mantle source, and the resultant size of the volcanic centre. This suggests that the scale of the eruption may essentially be controlled by asthenospheric mantle dynamics.