bluuebunny/crossref_metadata_2025 huggingface dataset:
On the azimuthal size of flux ropes near lunar orbit
Authors: Kiehas S. A. , Angelopoulos V. , Runov A. , Li S.‐S.
Published: June 2013

We present Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) dual‐probe observations of flux ropes in the Earth's magnetotail near lunar orbit. On 15 July 2011 between 0400 and 0500 UT, the ARTEMIS probes (P1 and P2) are separated by ∼ (9/10/3) RE(XGSW/YGSW/ZGSW). GSW denotes the Geocentric Solar Wind coordinate system and differs from the GSM coordinate system in that its X axis is antiparallel to the solar wind. P1 is near midnight and P2 in the postmidnight sector at ∼ −13 RE YGSW. During a ∼ 50 min interval on 15 July 2011, P1 crossed the current sheet and encountered a flux rope thereafter. During the same interval, P2 observed only one flux rope near the time P1 crossed the current sheet but no flux rope or traveling compression region (TCR) for P1's subsequent flux rope observation. A Tsyganenko‐Fairfield model and minimum variance analysis during the current sheet crossing are used to infer the current sheet location with respect to the probes. We find the distance between P2 and the plasma sheet boundary to be less than 3 RE. Under these circumstances, P2 would be expected to observe a TCR if the flux rope observed by P1 extended to the postmidnight location of P2. The lack of such observations indicates that, contrary to previous models and simulation results, flux ropes may be spatially confined in the dusk‐dawn direction and do not extend across the entire cross section of the tail near lunar orbit.
Are deep‐ocean‐generated surface‐wave microseisms observed on land?
Authors: Bromirski Peter D. , Stephen Ralph A. , Gerstoft Peter
Published: June 2013

Recent studies attribute land double‐frequency (DF) microseism observations to deep water generation. Here we show that near‐coastal generation is generally the dominant source region. This determination is based on observations at land and ocean seismic stations, buoys, gravity‐wave hindcasts, and on beamforming results from continental seismic arrays. Interactions between opposing ocean wave components generate a pressure excitation pulse at twice the ocean wave frequency that excites pseudo‐Rayleigh (pRg) wave DF microseisms. pRg generated in shallow coastal waters have most of their energy in the solid Earth (“elastic” pRg) and are observed by land‐based and seafloor seismometers as DF microseisms. pRg generated in the deep ocean have most of their energy in the ocean (“acoustic” pRg) and are continuously observed on the ocean bottom, but acoustic pRg does not efficiently transition onto continents. High‐amplitude DF signals over the [0.2, 0.3] Hz band observed on the deep seafloor are uncorrelated with continental observations and are not clearly detectable at individual continental stations or by land seismic‐array beamforming. Below 0.2 Hz, modeling and some observations suggest that some deep water‐generated elastic pRg energy can reach continental stations, providing that losses from scattering and transition across the continental‐shelf boundary to the shore are not substantial. However, most observations indicate that generally little deep‐ocean‐generated DF microseism energy reaches continental stations. Effectively, DF land observations are dominated by near‐coastal wave activity.
Discrepancies between the modeled and proxy‐reconstructed response to volcanic forcing over the past millennium: Implications and possible mechanisms
Authors: Mann Michael E. , Rutherford Scott , Schurer Andrew , Tett Simon F.B. , Fuentes Jose D.
Published: June 2013

We show that a systematic discrepancy between model simulations and proxy reconstructions of hemispheric temperature changes over the past millennium appears to arise from a small number of radiatively large volcanic eruptions. Past work has shown that accounting for this mismatch alone appears to reconcile inconsistencies between the overall amplitude of simulated and proxy‐reconstructed temperature changes. We provide empirical support for the previously posited hypothesis that this discrepancy may arise from threshold growth effects in tree line‐proximal trees that limit their response to large volcanic cooling events. Such threshold responses could lead to an absence of growth rings (as many as six accumulated years over the past eight centuries) for some fraction of tree line‐proximal trees, leading to a potential misalignment of volcanic cooling events in trees from climatically distinct regions, and a further attenuation and smearing of the volcanic cooling signal. Since the high‐frequency component of nearly all proxy reconstructions of past hemispheric temperature change is derived from tree ring data, this bias would likely impact nearly all such reconstructions. We show here that the discrepancy may have led to an underestimation bias in past studies attempting to infer equilibrium climate sensitivity from proxy temperature reconstructions of the past millennium.
Seasonal to multidecadal variability of the width of the tropical belt
Authors: Davis N. A. , Birner T.
Published: June 2013

An expansion of the tropical belt has been extensively reported in observations, reanalyses, and climate model simulations, but there is a great deal of uncertainty in estimates of the rate of widening as different diagnostics give a wide range of results. This study critically examines robust diagnostics for the width of the tropical belt to explore their seasonality, interannual variability, and multidecadal trends. The width based on the latitudes of the maximum tropospheric dry bulk static stability, measuring the difference in potential temperature between the tropopause and the surface, is found to be closely coupled to the width based on the subtropical jet cores on all time scales. In contrast, the tropical belt width and Northern Hemisphere edge latitudes based on the latitudes at which the vertically averaged stream function vanishes, a measure of the Hadley circulation's poleward edges, lag those of the other diagnostics by approximately 1month. The tropical belt width varies by up to 10° latitude among the diagnostics, with trends in the tropical belt width ranging from −0.5 to 2.0° per decade over the 1979–2012 period. Nevertheless, in agreement with previous studies, nearly all diagnostics exhibit a widening trend, although the stream function diagnostic exhibits a significantly stronger widening than either the jet or dry bulk stability diagnostics. Finally, GPS radio occultation observations are used to assess the ability of the reanalyses to reproduce the tropical belt width, finding that they better situate the latitudes of maximum bulk stability versus those of the subtropical jets.
Polymer monoliths as efficient solid phases for enzymatic polynucleotide degradation followed by fast HPLC analysis
Authors: Volokitina M. V. , Vlakh E. G. , Platonova G. A. , Vinokhodov D. O. , Tennikova T. B.
Published: June 2013

Two ribonuclease A bioreactors based on lab‐made macroporous monolithic columns and intended for polynucleotide degradation were prepared using in situ free‐radical polymerization. Different methods of enzyme immobilization were applied. In the first case, the biocatalyst molecule was attached to the solid surface via direct covalent binding, while in the second bioreactor the flexible‐chain synthetic polymer was used as an intermediate spacer. The effect of temperature, substrate flow rate, and loaded sample volume on the biocatalytic efficiency of the immobilized enzyme was examined. The kinetic parameters of the enzymatic degradation of synthetic polycytidylic acid were calculated and compared to those found for hydrolysis with soluble ribonuclease A. The monitoring of substrate splitting was carried out by means of fast anion‐exchange HPLC on an ultra‐short monolithic column (disk) using off‐ and on‐line analytical approaches.
PET‐CT and the detection of the asymptomatic recurrence or second primary lesions in the treated head and neck cancer patient
Authors: Dunsky Katherine A. , Wehrmann Daniel J. , Osman Medhat M. , Thornberry Brandon M. , Varvares Mark A.
Published: July 2013

Objectives/Hypothesis

The role of follow‐up and the detection of recurrent or new primary disease in cancer management remains to be defined. Specifically, the effectiveness and impact on survival of imaging studies that detects disease before it is symptomatic or noted on exam is unknown.

Study Design

Retrospective chart review.

Methods

A retrospective review was performed on a series of head and neck cancer patients (n = 123), at a single institution from February 18, 2004 to July 9, 2007, who had undergone nonstaging 18F‐fluorodeoxyglucose positron emission tomography‐computing tomography (FDG PET‐CT) scans as an integral part of the patient's follow‐up after definitive treatment. Each scan (n = 308) was evaluated by a board‐certified nuclear medicine physician, and final scan readings from each patient's medical record were reviewed for this study.

Results

Of the 123 patients in the study, 24 (20%) were noted to have asymptomatic lesions (either recurrent or new primaries) indicated on PET/CT (8% of surveillance scans) at an average interval of 35.7 weeks posttreatment. Asymptomatic lesions were detected most frequently at distant sites, with 50% being thoracic, but also included were primary (9%), regional (9%), and other distant (32%) sites. At last follow‐up of the 24 patients in whom an asymptomatic lesion was detected, 14 patients have died of disease; 10 patients remain alive, four with disease; and one patient had a subsequent recurrence treated and is currently disease‐free.

Conclusion

PET‐CT scanning is an effective tool for detecting asymptomatic disease in patients previously treated for head and neck cancer. Unfortunately, even with early detection of recurrent disease, the mortality rate remains high.

Level of Evidence

2B. Laryngoscope, 123:2161–2164, 2013
Modelling Structure Activity Landscapes with Cliffs: a Kernel Regression‐Based Approach
Authors: Tebby Cleo , Mombelli Enrico
Published: July 2013

Quantitative Structure‐Activity Relationship (QSAR) models are increasingly used in hazard and risk assessment. Even when models with linear relationships between activity and a small number of descriptors are built and validated regarding predictivity and statistical assumptions, similar structures can exhibit large differences in activity known as similarity paradoxes or activity cliffs. In order to reduce the impact that similarity paradoxes can have on predictions we have devised a statistical method based on Nadaraya‐Watson kernel regression. According to our method, activity cliffs filter out contributions of neighbouring chemicals especially along the cliff axis. Our method decreases density‐based certainty in particular for chemicals with strong prediction errors and the implementation of Structure‐Activity Landscape Index (SALI) curves shows that our method improves the prediction of activity cliff ranks. We also provide useful indications on the density‐based applicability domain and the reliability of individual predictions.
Lie‐group method for solving the problem of fission product behavior in nuclear fuel
Authors: Abd‐el‐Malek Mina B. , Hassan Hossam S.
Published: June 2013

Calculation of the gas atom concentration is an important feature of all physical models of fission gas release. We apply Lie‐group method for determining symmetry reductions to the diffusion equation describing the fission gas release from nuclear fuel. The resulting nonlinear ordinary differential equation is solved numerically using nonlinear finite difference method. Effects of the dimensionless group constant, the time, and the grain radius on the concentration diffusion function have been studied, and the results are plotted. It is found that the concentration of gas atoms increases as the dimensionless group constant, the power index, and the time increase, and it decreases with increase of the grain radius. Copyright © 2013 John Wiley & Sons, Ltd.
Solvability of reaction–diffusion model with variable exponents
Authors: Shangerganesh Lingeshwaran , Balachandran Krishnan
Published: June 2013

In this article, we study the existence and uniqueness of a weak solution of a degenerate reaction–diffusion parabolic system with variable exponents. This model describes the spread of epidemic diseases with a nonlinear diffusion operator. Copyright © 2013 John Wiley & Sons, Ltd.
13C‐NMR data of daphnane diterpenoids
Authors: Wang Hong‐Bing , Liu Li‐Ping , Wang Xiao‐Yang
Published: June 2013

Daphnane diterpenoids are mainly distributed in Thymelaeaceae and Euphorbiaceae and have various bioactivities. About 100 daphnane diterpenoids have been isolated from natural plants. In this review, we systematically summarize the 13C‐NMR data of daphnane diterpenoids isolated from natural plants over the past several decades and briefly discussed their biological activities and basic structural–activity relationship. Copyright © 2013 John Wiley & Sons, Ltd.
Real‐time motion correction in two‐dimensional multislice imaging with through‐plane navigator
Authors: Lin Wei , Nielsen Tim , Qin Qin , Mostofsky Stewart H. , Wei Juan , Huang Feng , Duensing George R.
Published: June 2013

Purpose

To develop a new real‐time strategy to detect and correct for full three‐dimensional rigid‐body motion in two‐dimensional multislice magnetic resonance imaging scans.

Methods

Two through‐plane navigator echoes collected on each imaging slice are used to reconstruct two orthogonal through‐plane navigator projection images both perpendicular to the imaged slices, within each repetition time. Rotation/translation within each through‐plane navigator image plane is detected using a regional image correlation measure that is robust against unaccounted orthogonal rotation and noise. An additional orbital navigator is used to detect rotation within the imaging plane and to reject intrarepetition time motion in real time.

Results

The efficacy of the proposed method was demonstrated with in vivo brain studies.

Conclusion

The proposed real‐time three‐dimensional motion correction method does not introduce any additional three‐dimensional radiofrequency excitation and does not require any additional hardware. Magn Reson Med 71:1995–2005, 2014. © 2013 Wiley Periodicals, Inc.
A new category of thermally stable poly(ether amide ether imide)s with increased solubility
Authors: Abbasi Aida , Mehdipour‐Ataei Shahram
Published: June 2013

Two new poly(ether amide ether imide)s (PEAEIs) were prepared from a new diamine (DA) containing ether, aliphatic, amide, naphthyl and pyridine functional groups that resulted flexible and thermally stable ultimate polymers. The DA was synthesized via two steps, starting from nucleophilic substitution reaction of 1,8‐diamino‐3,6‐dioxaoctane with 6‐chloronicotinoyl chloride in the presence of propylene oxide which, afforded dichloro‐diamide (DCDA) compound. In the second step for the preparation of DA, reaction of DCDA compound with 5‐amino‐1‐naphthol in the presence of K2CO3 was achieved. The new DA was then polycondensed with 2,2'‐bis‐(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride and pyromellitic dianhydride to produce PEAEIs. The precursor, monomer and obtained polymers were entirely characterized by FT‐IR and 1H‐NMR spectroscopy and elemental analysis techniques. The physical properties of the polymers including solubility, thermal behavior, thermal stability, inherent viscosity, morphology and mechanical properties were studied. The new PEAEIs exhibited favorable balance of physical and thermal properties, and their solubility was improved without sacrificing their thermal stability. Copyright © 2013 John Wiley & Sons, Ltd.
Characterisation of Phenolic Compounds by HPLC–TOF/IT/MS in Buds and Open Flowers of ‘Chemlali’ Olive Cultivar
Authors: Taamalli Amani , Abaza Leila , Arráez Román David , Segura Carretero Antonio , Fernández Gutiérrez Alberto , Zarrouk Mokhtar , Ben Youssef Nabil
Published: June 2013

Introduction

Plant phenolics are secondary metabolites that constitute one of the most widely occurring groups of phytochemicals that play several important functions in plants. In olive (Olea europaea L), there is not enough information about the occurrence of these compounds in buds and flowers.

Objective

To conduct a comprehensive characterisation of buds and open flowers from the olive cultivar ‘Chemlali’.

Methods

The polar fraction of buds and open flowers was extracted using solid–liquid extraction with hydro‐alcoholic solvent. Then extracts were analysed using high performance liquid chromatography (HPLC) coupled to electrospray ionisation time‐of‐flight mass spectrometry (ESI/TOF/MS) and electrospray ionisation ion‐trap tandem mass spectrometry (ESI/IT/MS2) operating in negative ion mode.

Results

Phenolic compounds from different classes including secoiridoids, flavonoids, simple phenols, cinnamic acid derivatives and lignans were tentatively identified in both extracts. Qualitatively, no significant difference was observed between flower buds and open flowers extracts. However, quantitatively the secoiridoids presented higher percentage of total phenols in open flowers (41.7%) than in flower buds (30.5%) in contrast to flavonoids, which decreased slightly from 38.1 to 26.7%. Cinnamic acid derivatives and simple phenols did not show any change. Lignans presented the lowest percentage in both extracts with an increase during the development of the flower bud to open flower.

Conclusion

The HPLC–TOF/IT/MS allowed the characterisation, for the first time, of the phenolic profile of extracts of ‘Chemlali’ olive buds and open flowers, proving to be a very useful technique for the characterisation and structure elucidation of phenolic compounds. Copyright © 2013 John Wiley & Sons, Ltd.
Tanshinone IIA Induces Autophagic Cell Death via Activation of AMPK and ERK and Inhibition of mTOR and p70 S6K in KBM‐5 Leukemia Cells
Authors: Yun Sun‐Mi , Jung Ji Hoon , Jeong Soo‐Jin , Sohn Eun Jung , Kim Bonglee , Kim Sung‐Hoon
Published: June 2013

Although tanshinone IIA (Tan IIA) from Salviae miltiorrhizae was known to induce apoptosis in various cancers, its underlying mechanism of autophagic cell death was not reported yet. Thus, in the present study, the molecular mechanism of autophagic cell death by Tan IIA was investigated in KBM‐5 leukemia cells. Tan IIA significantly increased the expression of microtubule‐associated protein light chain 3 (LC3) II as a hallmark of autophagy in western blotting and immunofluorescence staining. Tan IIA augmented the phosphorylation of adenosine monophosphate‐activated protein kinase (AMPK) and attenuated the phosphorylation of mammalian target of rapamycin (mTOR) and p70 S6K in a dose‐dependent manner. Conversely, autophagy inhibitor 3‐methyladenine partly reversed the cytotoxicity and the phosphorylation of AMPK, mTOR and p70 S6K induced by Tan IIA in KBM‐5 leukemia cells. In addition, Tan IIA dramatically activated the extracellular signal regulated kinase (ERK) signaling pathway including Raf, ERK and p90 RSK in a dose‐dependent and time‐dependent manner. Consistently, ERK inhibitor PD184352 suppressed LC3‐II activation induced by Tan IIA, whereas PD184352 and PD98059 did not affect poly (ADP‐ribose) polymerase cleavage and sub‐G1 accumulation induced by Tan IIA in KBM‐5 leukemia cells. Furthermore, Tan IIA could induce autophagy via LC3‐II activation in various cancer cells such as prostate (PC‐3), multiple myeloma (U266), lung (NCI‐H460), and breast (MDA‐MB‐231) cells. Overall, these findings suggest that Tan IIA induces autophagic cell death via activation of AMPK and ERK and inhibition of mTOR and p70 S6K in KBM‐5 cells as a potent natural compound for leukemia treatment. Copyright © 2013 John Wiley & Sons, Ltd.
Integrating Six Sigma Culture and TPM Framework to Improve Manufacturing Performance in SMEs
Authors: Kumar Sharma Rajiv , Gopal Sharma Rajan
Published: June 2013

Worldwide, small and medium enterprises (SMEs) have been accepted as the engine of economic growth, especially in the emerging economies, and for promoting equitable development their contribution as a component to nation's infrastructure is relatively high. Global competition forces SMEs to improve their competitiveness by enhancing their manufacturing performance. Hence, they have to pay attention to the reliability of their production processes as well as their commitment to quality management practices. In present times, because of automation and large‐scale mechanization, higher plant availability, better product quality and longer equipment life had assumed considerable significance among the SMEs.

In order to meet the above challenges, adoption and practice of proactive maintenance strategies along with execution of best management practices, i.e. lean Six Sigma (LSS), has become essential for organizations to bring down maintenance and production costs. As evident from literature, both total productive maintenance (TPM) and Six Sigma are key business process strategies employed by SMEs to enhance their manufacturing performance. However, whilst there is significant research information available on implementing these systems in an independent manner, there is little information available relating to the integration of these approaches to provide a unified and highly effective implementation framework. The purpose of this paper is thus to develop an integrated model based on Six Sigma and TPM framework focusing on adding performance indicators. The goals of the study were achieved by utilizing various tools such as ‘brainstorming sessions, pareto analysis fish‐bone diagrams, histograms, FMEA, box plots, control charts and process capability plots for analysis’. While implementation of such twin framework requires greater management commitment in terms of training, resources and integration, they are also expected to provide higher levels of equipment and plant performance as evident from the results. The results show significant improvement in OEE level (Before 50, 54 and after 76, 83 for M/C –I and M/c‐II), reduction in rework (from 22% to 10%), reduction in maintenance versus operation cost (from 30% to 10%) and reduction in defect rate (from 24.82% to 5%) and average outgoing quality level (from 30% to 5%). The substantial improvement in sigma level from 2.16 and 2.64 to 4.01 and 4.12 for M/C –I and M/C‐II resulted in financial savings of approximately $2 m per annum. Copyright © 2013 John Wiley & Sons, Ltd.
PREDICTING HABITAT RESPONSE TO FLOW USING GENERALIZED HABITAT MODELS FOR TROUT IN ROCKY MOUNTAIN STREAMS
Authors: Wilding T. K. , Bledsoe B. , Poff N. L. , Sanderson J.
Published: June 2013

Dams and water diversions can dramatically alter the hydraulic habitats of stream ecosystems. Predicting how water depth and velocity respond to flow alteration is possible using hydraulic models, such as Physical Habitat Simulation (PHABSIM); however, such models are expensive to implement and typically describe only a short length of stream (102 m). If science is to keep pace with development, then more rapid and cost‐effective models are needed. We developed a generalized habitat model (GHM) for brown and rainbow trout that makes similar predictions to PHABSIM models but offers a demonstrated reduction in survey effort for Colorado Rocky Mountain streams. This model combines the best features of GHMs developed elsewhere, including the options of desktop (no‐survey) or rapid‐survey models. Habitat–flow curves produced by PHABSIM were simplified to just two site‐specific components: (i) Q95h (flow at 95% of maximum habitat) and (ii) Shape. The Shape component describes the habitat–flow curves made dimensionless by dividing flow increments by Q95h and dividing habitat (weighted usable area) increments by maximum habitat. Both components were predicted from desktop variables, including mean annual flow, using linear regression. The rapid‐survey GHM produced better predictions of observed habitat than the desktop GHM (rapid‐survey model explained 82–89% variance for independent validation sites; desktop 68–85%). The predictive success of these GHMs was similar to other published models, but survey effort to achieve that success was substantially reduced. Habitat predicted by the desktop GHM (using geographic information system data) was significantly correlated with the abundance of large brown trout (p < 0.01) but not smaller trout. Copyright © 2013 John Wiley & Sons, Ltd.
Integrating security mechanisms into embedded systems by domain‐specific modelling
Authors: Vasilevskaya Maria , Gunawan Linda Ariani , Nadjm‐Tehrani Simin , Herrmann Peter
Published: June 2013

Embedded devices are crucial enablers of the Internet of Things and become increasingly common in our daily life. They store, manipulate and transmit sensitive information and, therefore, must be protected against security threats. Due to the security and also resource constraint concerns, designing secure networked embedded systems is a difficult task. Model‐based development (MBD) is promoted to address complexity and ease the design of software intensive systems. We leverage MBD and domain‐specific modelling to characterise common issues related to security and embedded systems that are specific to a given application domain. Security‐specific knowledge relevant for a certain application domain is represented in the form of an adapted information security ontology. Further, the elements of the ontology are associated with security building blocks modelled with the MBD method SPACE. The selection of relevant security building blocks is based on (i) assets automatically elicited from the functional models, (ii) domain security knowledge captured by the security expert and (iii) the platform adopted by the embedded system engineer. A tool is developed to support the steps supporting this methodology and help to bridge between the security and embedded systems domains. We illustrate our approach with a case study from the smart metering domain. © 2013 The Authors. Security and Communication Networks published by John Wiley & Sons, Ltd.
Secure universal designated verifier identity‐based signcryption
Authors: Lin Changlu , Tang Fei , Ke Pinhui , Harn Lein , Zhang Shengyuan
Published: June 2013

In 2003, Steinfeld et al. introduced the notion of universal designated verifier signature (UDVS), which allows a signature holder, who receives a signature from the signer, to convince a designated verifier whether he is possession of a signer's signature; at the same time, the verifier cannot transfer such conviction to anyone else. These signatures devote to protect the receiver's privacy, that is, the receiver may want to prove to any designated verifier who he is in possession of such signature signed by the known signer but reluctant to disclose it. Moreover, the receiver also does not want the verifier to be able to convince anyone that he is in possession of such signature. In the existing UDVS schemes, a secure channel is required between the signer and the signature holder to transfer the signature. This paper, for the first time, proposes the notion of universal designated verifier signcryption without this secure channel by combining the notions of UDVS and signcryption. We give the formal definitions and a concrete construction of universal designated verifier identity‐based signcryption scheme. We also give the formal security proofs for our scheme under the random oracle model. Copyright © 2013 John Wiley & Sons, Ltd.
Generating mosaics for lineage analysis in flies
Authors: Lee Tzumin
Published: June 2013

By generating and studying mosaic organisms, we are learning how intricate tissues form as cells proliferate and diversify through organism development. FLP/FRT‐mediated site‐specific mitotic recombination permits the generation of mosaic flies with efficiency and control. With heat‐inducible or tissue‐specific FLP transgenes at our disposal, we can engineer mosaics carrying clones of homozygous cells that come from specific pools of heterozygous precursors. This permits detailed cell lineage analysis followed by mosaic analysis of gene functions in the underlying developmental processes. Expression of transgenes (e.g., reporters) only in the homozygous cells enables mosaic analysis in the complex nervous system. Tracing neuronal lineages by using mosaics revolutionized mechanistic studies of neuronal diversification and differentiation, exemplifying the power of genetic mosaics in developmental biology. WIREs Dev Biol 2014, 3:69–81. doi: 10.1002/wdev.122

This article is categorized under:

Nervous System Development > Flies

Technologies > Generating Chimeras and Lineage Analysis
The configuration of water on rough natural surfaces: Implications for understanding air‐water interfacial area, film thickness, and imaging resolution
Authors: Kibbey Tohren C. G.
Published: June 2013

Previous studies of air‐water interfacial areas in unsaturated porous media have often distinguished between interfacial area corresponding to water held by capillary forces between grains and area corresponding to water associated with solid surfaces. The focus of this work was on developing a better understanding of the nature of interfacial area associated with solid surfaces following drainage of porous media. Stereoscopic scanning electron microscopy was used to determine surface elevation maps for eight different surfaces of varying roughness. An algorithm was developed to calculate the true configuration of an air‐water interface in contact with the solid surface as a function of capillary pressure. The algorithm was used to calculate surface‐associated water configurations for capillary pressures ranging from 10 to 100 cm water. The results of the work show that, following drainage, the configuration of surface‐associated water is dominated by bridging of macroscopic surface roughness features over the range of capillary pressures studied, and nearly all of the surface‐associated water is capillary held. As such, the thicknesses of surface‐associated water were found to be orders‐of‐magnitude greater than might be expected at the same capillary pressures based on calculations of adsorbed film thickness. The fact that capillary forces in air‐water interfaces dominate surface‐associated water configuration means that interface shapes are largely unaffected by microscopic surface roughness, and interfaces are considerably smoother than the underlying solid. As such, calculations suggest that microscopic surface roughness likely has minimal impact on the accuracy of surface‐associated air‐water interfacial areas determined by limited‐resolution imaging methods such as computed microtomography.
Influence of natural convection in a porous medium when producing from borehole heat exchangers
Authors: Bringedal C. , Berre I. , Nordbotten J. M.
Published: June 2013

Convection currents in a porous medium form when the medium is subject to sufficient heating from below (or equivalently, cooling from above) or when cooled or heated from the side. In the context of geothermal energy extraction, we are interested in how the convection currents transport heat when a sealed borehole containing cold fluid extracts heat from the porous medium; also known as a borehole heat exchanger. Using pseudospectral methods together with domain decomposition, we consider two scenarios for heat extraction from a borehole; one system where the porous medium is initialized with constant temperature in the vertical direction and one system initialized with a vertical temperature gradient. We find the convection currents to have a positive effect on the heat extraction for the case with a constant initial temperature in the porous medium, and a negative effect for some of the systems with an initial temperature gradient in the porous medium: Convection gives a negative effect when the borehole temperature is close the initial temperature in the porous medium, but gradually provides a positive effect if the borehole temperature is decreased and the Rayleigh number is larger.
A new theoretical model accounting for film flow in unsaturated porous media
Authors: Wang Yunquan , Ma Jinzhu , Zhang Yali , Zhao Menzhu , Edmunds W. Mike
Published: June 2013

Commonly used soil hydraulic models that account for capillary forces often do not perform well when water flow occurs in thin liquid films in unsaturated porous media. A new theoretical soil water retention curve model was formulated based on the film thickness function that accounts for matric potential. Coupling this new model with a modified Tokunaga model that considers hydraulic conductivity yields a theoretical and mathematically simple soil hydraulic model that accounts for film flow in unsaturated porous media. Inverse modeling of an evaporation experiment showed that the new model provides a good description of water flow at low water contents. The combination of van Genuchten model with the modified Tokunaga model performed best in inverse modeling; however, the fitted parameters did not describe water flow under drier conditions because of the higher hydraulic conductivity and sharper water potential gradient when the water content approached the residual water content, which caused severe overestimation of water loss. Simulation of the water dynamic in a 2 m profile using the modified Tokunaga model combined with the new theoretical soil water retention curve model provided reliable results for water changes under field conditions, including very dry conditions.
A generalized Grubbs‐Beck test statistic for detecting multiple potentially influential low outliers in flood series
Authors: Cohn T. A. , England J. F. , Berenbrock C. E. , Mason R. R. , Stedinger J. R. , Lamontagne J. R.
Published: June 2013

The Grubbs‐Beck test is recommended by the federal guidelines for detection of low outliers in flood flow frequency computation in the United States. This paper presents a generalization of the Grubbs‐Beck test for normal data (similar to the Rosner (1983) test; see also Spencer and McCuen (1996)) that can provide a consistent standard for identifying multiple potentially influential low flows. In cases where low outliers have been identified, they can be represented as “less‐than” values, and a frequency distribution can be developed using censored‐data statistical techniques, such as the Expected Moments Algorithm. This approach can improve the fit of the right‐hand tail of a frequency distribution and provide protection from lack‐of‐fit due to unimportant but potentially influential low flows (PILFs) in a flood series, thus making the flood frequency analysis procedure more robust.
Hepatic Resection for Hepatocellular Carcinoma Patients on Hemodialysis for Uremia: A Nationwide Cohort Study
Authors: Yeh Chun‐Chieh , Lin Jaw‐Town , Jeng Long‐Bin , Charalampos Iakovidis , Chen Tzu‐Ting , Lee Teng‐Yu , Wu Ming‐Shiang , Kuo Ken N. , Liu Yi‐Ya , Wu Chun‐Ying
Published: June 2013

Background

The association between uremia and survival outcomes of patients undergoing hepatic resection for hepatocellular carcinoma (HCC) has not been well investigated, particularly for perioperative complications. This nationwide cohort study aimed to compare survival outcomes as well as perioperative mortality and complications between uremia‐HCC patients and non‐uremia‐HCC patients who underwent hepatic resection.

Methods

Using Taiwan’s National Health Institute Research Database, 149 uremia‐HCC patients who underwent hepatic resection between 1996 and 2008 were enrolled. The control group comprised 596 HCC patients who also received hepatic resection during the same time period. The two groups were matched for age, gender, viral hepatitis status, and underlying liver cirrhosis. Disease‐free survival, overall survival, and perioperative complications were compared between the two groups.

Results

For the uremia‐HCC cohort, the 1‐, 5‐, and 10‐year overall and disease‐free survival rates were 86, 52, and 38 %, as well as 77, 27, and 18 %, respectively. The survival outcomes were comparable between uremia‐HCC cohort and the HCC cohort, regardless of extent of hepatic resection. As for perioperative complications, the uremia‐HCC cohort had a higher risk of postoperative infections requiring invasive interventions as well as an increased risk of life‐threatening heart‐associated complications, compared to the HCC cohort.

Conclusions

Uremia did not influence survival outcomes between the uremia‐HCC and the HCC cohorts, irrespective of extent of hepatic resection. This study urges a better perioperative care strategy to avoid potential cardiac and infectious complications in uremia‐HCC patients.
Gunshot Wounds to the Face: Emergency Interventions and Outcomes
Authors: Orthopoulos George , Sideris Antonios , Velmahos Elpida , Troulis Maria
Published: June 2013

Background

Gunshot wounds to the face (GSWF) may produce life‐threatening injuries. Our objective is to describe outcomes of and factors related to interventions for urgent airway control (UAC) and urgent bleeding control (UBC) as well as to analyze complications associated with GSWF.

Methods

This was a retrospective study of 155 GSWF patients who were admitted to two Level 1 academic trauma centers over an 11‐year period. Demographic details, injuries sustained, interventions performed, and timing of the interventions were recorded. Morbidity and mortality data were evaluated.

Results

Overall, 115 (74 %) patients suffered isolated GSWF, and none died. Of the 90 (58 %) patients requiring UAC, only three had a cricothyroidotomy. Of the 41 (26 %) patients requiring UBC, only four had angiographic embolization. Intraoral involvement and extrafacial injuries were associated with both UAC and UBC. Overall, 75 patients (48 %) required operations on the bones, eyes, or both. Complications developed in 14 and were treated successfully.

Conclusions

UAC and UBC are required frequently after GSWF and are associated with intraoral involvement and injuries beyond the face. Simple methods, such as orotracheal intubation and packing, are typically sufficient for successful management. About half of the patients need further surgery, with infrequent morbidity.
Consequences of ratio‐dependent predation by wolves for elk population dynamics
Authors: Hebblewhite Mark
Published: June 2013

A growing number of studies suggest ratio‐dependence may be common in many predator–prey systems, yet in large mammal systems, evidence is limited to wolves and their prey in Isle Royale and Yellowstone. More importantly, the consequences of ratio‐dependent predation have not been empirically examined to understand the implications for prey. Wolves recolonized Banff National Park in the early 1980s, and recovery was correlated with significant elk declines. I used time‐series data of wolf kill rates of elk, wolf and elk densities in winter from 1985–2007 to test for support for prey‐, ratio‐, or predator dependent functional and numeric responses of wolf killing rate to elk density. I then combined functional and numeric responses to estimate the total predation response to identify potential equilibrium states. Evidence suggests wolf predation on elk was best described by a type II ratio‐dependent functional response and a type II numeric response that lead to inversely density‐dependent predation rate on elk. Despite support for ratio‐dependence, like other wolf‐prey systems, there was considerable uncertainty amongst functional response models, especially at low prey densities. Consistent with predictions from ratio‐dependent models, however, wolves contributed to elk population declines of over 80 % in our Banff system. Despite the statistical signature for ratio‐dependence, the biological mechanism remains unknown and may be related to multi‐prey dynamics in our system. Regardless, ratio‐dependent models strike a parsimonious balance between theory and empiricism, and this study suggests that large mammal ecologists need to consider ratio‐dependent models in predator–prey dynamics.
Factors involved in the response to change of agitation rate during cellulase production fromPenicillium decumbensJUA10-1
Authors: Wang Mingyu , He Didi , Liang Ya , Liu Kuimei , Jiang Baojie , Wang Fangzhong , Hou Shaoli , Fang Xu
Published: July 2013

Improvement of agitation is a commonly used approach for the optimization of fermentation processes. In this report, the response to improving agitation rate from 150 to 250 rpm on cellulase production from Penicillium decumbens JUA10-1 was investigated. It was shown that the production of all the major components of the cellulase mixture increased following improved agitation. Further investigations showed that at least three factors are involved in this improvement: the improved biomass accumulation, proportion of active/mature cellulases, and cellulase transcription level. The transcription levels of the cellulase repressing transcription factor ace1 and the cellulase activating transcription factor xlnR, however, both declined when a higher agitation was applied. These observations, along with our analysis of the carbon catabolite repressor CreA, lead to the suggestion that the molecular mechanism underlying improved cellulase transcription is the competition of two concurrent effects following improved agitation: CreA-mediated derepression induced by the downregulation of ace1, and CreA-mediated deactivation induced by the downregulation of xlnR.
Collective Efficacy as a Task Specific Process: Examining the Relationship Between Social Ties, Neighborhood Cohesion and the Capacity to Respond to Violence, Delinquency and Civic Problems
Authors: Wickes Rebecca , Hipp John R. , Sargeant Elise , Homel Ross
Published: June 2013

In the neighborhood effects literature, collective efficacy is viewed as the key explanatory process associated with the spatial distribution of a range of social problems. While many studies usefully focus on the consequences of collective efficacy, in this paper we examine the task specificity of collective efficacy and consider the individual and neighborhood factors that influence residents’ perceptions of neighborhood collective efficacy for specific tasks. Utilizing survey and administrative data from 4,093 residents nested in 148 communities in Australia, we distinguish collective efficacy for particular threats to social order and assess the relative importance of social cohesion and neighborhood social ties to the development of collective efficacy for violence, delinquency and civic/political issues. Our results indicate that a model separating collective efficacy for specific problems from social ties and the more generalized notions of social cohesion is necessary when understanding the regulation potential of neighborhoods.
Peering into a Chilean Black Box: Parental Storytelling in Pediatric Genetic Counseling
Authors: Ordonez Jessica , Margarit Sonia , Downs Katy , Yashar Beverly M.
Published: June 2013

While genetic counseling has expanded to multiple international settings, research about providing culturally sensitive services to non‐U.S. patients is limited. To gain insights, we utilized a process study to explore parental communication in pediatric genetics clinics in Chile. We utilized a phenomenological hermeneutic approach to assess storytelling in six pediatric sessions that were conducted in Spanish, and translated into English. The majority of the sessions focused on information gathering (35 %), and providing medical (20 %) and genetics education (18 %). The 14 instances of storytelling we identified usually emerged during information gathering, genetics education, and the closing of the session. Stories illustrated parental efforts to create a cognitive and emotional context for their child's genetic diagnosis. Parents emerged as competent caregivers who discussed the role of the child as a social being in the family and the larger community. Our analysis found that genetic counseling sessions in the U.S. and Chile are structured similarly and although communication is not a balanced process, parents use storytelling to participate as active agents in the session. Via storytelling, we learned that parents are working to understand and gain control over their child's genetic diagnosis by relying on mechanisms that extend beyond the genetics appointment.
Political Islam and Islam in Politics in Europe
Authors: Colombo Valentina
Published: June 2013

About 5% of the EU's inhabitants identify themselves as Muslims. Thus, there is an increasing presence of Muslims and Islam in European society, and this has caused an increase in their presence in politics. Muslims living in Europe have entered the political arena in different ways, both with Islamic parties and as candidates for the main parties. An analysis of the evolution of Muslim political participation in Europe shows that Islamic parties have largely failed, while politicians with Muslim backgrounds who join parties with no Islamic identity have obtained good results. This means that Muslims with a strong religious identity are still seen as a world apart in Europe, while Muslims who either have a secular identity or who live their faith as a personal belief are considered to be ordinary citizens who people vote for based on their inner qualities, regardless of their religion.
Confidence via correction: The effect of judgment correction on consumer confidence
Authors: Petersen Francine Espinoza , Hamilton Rebecca W.
Published: June 2013

At times, consumers are motivated to reduce the influence of a product recommendation on their judgments. Based on previous research, it is unclear whether this correction process will increase or decrease consumers' confidence in their judgments. We find that source credibility moderates the effect of correction on confidence: correction decreases confidence when a product recommendation comes from a high credibility source but increases confidence when the same message comes from a low credibility source. As a result, correction increases the effectiveness of recommendations from low credibility sources on purchase intentions. Notably, this “confidence via correction” effect is further moderated by elaboration, such that the effect is attenuated for high elaboration consumers. Our results have implications for understanding consumers' reactions to persuasive messages and for both marketing practitioners and consumer protection agencies using correction cues to influence message persuasiveness.
Do Fine Wines Blend with Crude Oil? Seizing the Transmission of Mean and Volatility Between Two Commodity Prices
Authors: Bouri Elie I.
Published: July 2013

This study applies a multivariate model to examine the dynamics of mean and volatility transmission between fine wine and crude oil prices using daily observations from January 2004 to December 2011. The results suggest that the crude oil mean determines the wine market. In each series, volatility persistence is high and significant; innovations in each market seem to include figures that are valuable to risk managers seeking to predict volatility in other markets. During the financial crisis of 2008, wine and oil conditional volatilities climbed but then returned to their overall pre-crisis levels. (JEL Classifications: G11, G15, Q14, Q40)
Quantum simulation of low-temperature metallic liquid hydrogen
Authors: Chen Ji , Li Xin-Zheng , Zhang Qianfan , Probert Matthew I. J. , Pickard Chris J. , Needs Richard J. , Michaelides Angelos , Wang Enge
Published: June 2013

The melting temperature of solid hydrogen drops with pressure above ~65 GPa, suggesting that a liquid state might exist at low temperatures. It has also been suggested that this low-temperature liquid state might be non-molecular and metallic, although evidence for such behaviour is lacking. Here we report results for hydrogen at high pressures using ab initio methods, which include a description of the quantum motion of the protons. We determine the melting temperature as a function of pressure and find an atomic solid phase from 500 to 800 GPa, which melts at <200 K. Beyond this and up to 1,200 GPa, a metallic atomic liquid is stable at temperatures as low as 50 K. The quantum motion of the protons is critical to the low melting temperature reported, as simulations with classical nuclei lead to considerably higher melting temperatures of ~300 K across the entire pressure range considered.