bluuebunny/crossref_metadata_2025 huggingface dataset:
All‐optical time‐domain demultiplexing of 170.8 Gbit/s signal in chalcogenide GeAsSe microstructured fibre
Authors: Le S.D. , Gay M. , Bramerie L. , Chartier T. , Thual M. , Simon J.‐C. , Brilland L. , Méchin D. , Toupin P. , Troles J.
Published: January 2013

A report is presented on four‐wave‐mixing‐based all‐optical time‐domain demultiplexing of a 170.8 Gbit/s signal down to 42.7 Gbit/s in a chalcogenide GeAsSe microstructured fibre. The high nonlinearity of the fibre allows error‐free and low power penalty operation with only 56 mW of total input average power.
Bandstop response of microstrip stepped impedance ring with rotational symmetry
Authors: Jin X.H. , Huang X.D. , Cheng C.H.
Published: January 2013

The bandstop behaviour of a stepped impedance microstrip ring is studied. The ring is composed of four sections of microstrip line, which are equal in electrical length, but different in impedance. When the impedances of the lines meet the condition of rotational symmetry, a bandstop response could be obtained. At the central frequency of the stopband, the electrical length of the lines is 90°. By tuning the lines' impedances, the bandwidth could be finely adjusted, typically from 0.5 to 40%. Prototypes are designed, fabricated and measured. Good agreements are observed between the measured and the simulated data. The measured data shows that the 3 dB bandwidth is 24%, with a rejection level of −32 dB at the central frequency 1.99 GHz. In addition, the measured matching within the passband is good, as predicted.
RCS enhancement of flattened dihedral corner reflector using reflectarray approach
Authors: Lipuma D. , Méric S. , Gillard R.
Published: January 2013

Presented is the use of a reflectarray‐based structure in order to enhance the radar cross‐section (RCS) of a flattened dihedral corner reflector. Phase‐shifting cells are printed on the panels of the reflector to steer the reflected beam so that a retrodirective radiation is obtained. An experimental validation is given at 9 GHz.
Suppression of photo‐darkening effect by Ca additive in Yb‐doped silica glass fibre
Authors: Sugiyama S. , Fujimoto Y. , Murakami M. , Nakano H. , Sato T. , Shiraga H.
Published: January 2013

It is found that Ca additive effectively suppresses the photo‐darkening effect in Yb‐doped silica fibre even at 6.0 wt% of high Yb2O3 concentration. Ca ion works as a stabiliser to maintain the Yb3+ valence state. It is hypothesised that this phenomenon may reflect the local charge balance effect in silica glass. This Yb‐Ca co‐doped silica fibre can be useful for high‐power fibre lasers.
Shortcomings of the bond orientational order parameters for the analysis of disordered particulate matter
Authors: Mickel Walter , Kapfer Sebastian C. , Schröder-Turk Gerd E. , Mecke Klaus
Published: January 2013

Local structure characterization with the bond-orientational order parameters q4, q6, … introduced by Steinhardt et al. [Phys. Rev. B 28, 784 (1983)10.1103/PhysRevB.28.784] has become a standard tool in condensed matter physics, with applications including glass, jamming, melting or crystallization transitions, and cluster formation. Here, we discuss two fundamental flaws in the definition of these parameters that significantly affect their interpretation for studies of disordered systems, and offer a remedy. First, the definition of the bond-orientational order parameters considers the geometrical arrangement of a set of nearest neighboring (NN) spheres, NN(p), around a given central particle p; we show that the choice of neighborhood definition can have a bigger influence on both the numerical values and qualitative trend of ql than a change of the physical parameters, such as packing fraction. Second, the discrete nature of neighborhood implies that NN(p) is not a continuous function of the particle coordinates; this discontinuity, inherited by ql, leads to a lack of robustness of the ql as structure metrics. Both issues can be avoided by a morphometric approach leading to the robust Minkowski structure metrics \documentclass[12pt]{minimal}\begin{document}$q_l^{\prime }$\end{document}ql′. These \documentclass[12pt]{minimal}\begin{document}$q_l^{\prime }$\end{document}ql′ are of a similar mathematical form as the conventional bond-orientational order parameters and are mathematically equivalent to the recently introduced Minkowski tensors [G. E. Schröder-Turk et al., Europhys. Lett. 90, 34001 (2010)10.1209/0295-5075/90/34001; S. Kapfer et al., Phys. Rev. E 85, 030301–R (2012)10.1103/PhysRevE.85.030301].
Spatiotemporal structure of a millimetric annular dielectric barrier discharge plasma actuator
Authors: Humble R. A. , Craig S. A. , Vadyak J. , McClure P. D. , Hofferth J. W. , Saric W. S.
Published: January 2013

The spatiotemporal structure of a millimetric annular dielectric barrier discharge plasma actuator is investigated using a photomultiplier tube, a high-sensitivity camera, particle image velocimetry, and electrohydrodynamics simulations. Plasma actuators have typically demonstrated their utility in flow separation control, but on a millimetric scale they have also shown to be promising in the control of crossflow instabilities in crossflow-dominated laminar-turbulent boundary-layer transition. In view of the subtleties associated with creating an initial disturbance to excite subcritical wavelengths, it is desirable to characterize the local plasma discharge structure, body force organization, and induced velocity field in detail. The results show that, similar to their linear centimetric counterpart, the plasma discharge has a highly dynamic and somewhat organized spatiotemporal structure. Under quiescent flow conditions, the actuator induces a velocity field that consists of two counter-rotating vortices, accompanied by a wall-normal synthetic jet region, which in three-dimensions describes a toroidal vortex around the aperture's periphery. The surprising result, however, is that these vortices rotate in the opposite direction to vortices generated by similar centimetric annular designs. Three-dimensional electrohydrodynamics simulations correctly reproduce this behavior. Because the body force organization may be qualitatively perceived as being the axisymmetric counterpart of the more classical linear actuator, this flow reversal is thought to be due to the actuator scale. When an array of millimetric actuators is considered in close proximity, an interaction takes place between the vortices created from each actuator and those of neighboring actuators, resulting in a significant reduction in vortex size compared with the single aperture case, accompanied by an increase in the maximum induced flow velocity magnitude.
Bistability and hysteresis of maximum-entropy states in decaying two-dimensional turbulence
Authors: Loxley P. N. , Nadiga B. T.
Published: January 2013

We propose a theory that qualitatively predicts the stability and equilibrium structure of long-lived, quasi-steady flow states in decaying two-dimensional turbulence. This theory combines a maximum entropy principal with a nonlinear parameterization of the vorticity-stream-function dependency of such long-lived states. In particular, this theory predicts unidirectional-flow states that are bistable, exhibit hysteresis, and undergo large abrupt changes in flow topology; and a vortex-pair state that undergoes continuous changes in flow topology. These qualitative predictions are confirmed in numerical simulations of the two-dimensional Navier-Stokes equation. We discuss limitations of the theory, and why a reduced quantitative theory of long-lived flow states is difficult to obtain. We also provide a partial theoretical justification for why certain sets of initial conditions go to certain long-lived flow states.
Bcc crystal-fluid interfacial free energy in Yukawa systems
Authors: Heinonen V. , Mijailović A. , Achim C. V. , Ala-Nissila T. , Rozas R. E. , Horbach J. , Löwen H.
Published: January 2013

We determine the orientation-resolved interfacial free energy between a body-centered-cubic (bcc) crystal and the coexisting fluid for a many-particle system interacting via a Yukawa pair potential. For two different screening strengths, we compare results from molecular dynamics computer simulations, density functional theory, and a phase-field-crystal approach. Simulations predict an almost orientationally isotropic interfacial free energy of 0.12kBT/a2 (with kBT denoting the thermal energy and a the mean interparticle spacing), which is independent of the screening strength. This value is in reasonable agreement with our Ramakrishnan-Yussouff density functional calculations, while a high-order fitted phase-field-crystal approach gives about 2−3 times higher interfacial free energies for the Yukawa system. Both field theory approaches also give a considerable anisotropy of the interfacial free energy. Our result implies that, in the Yukawa system, bcc crystal-fluid free energies are a factor of about 3 smaller than face-centered-cubic crystal-fluid free energies.
An effective energy gradient expression for divide-and-conquer second-order Møller–Plesset perturbation theory
Authors: Kobayashi Masato , Nakai Hiromi
Published: January 2013

We recently proposed a linear-scaling evaluation scheme for the second-order Møller–Plesset perturbation (MP2) energy based on the divide-and-conquer (DC) method [M. Kobayashi, Y. Imamura, and H. Nakai, J. Chem. Phys. 127, 074103 (2007)10.1063/1.2761878]. In this paper, we propose an approximate but effective expression for the first derivative of the DC-MP2 energy. The present scheme evaluates the one- and two-body density matrices, which appear in the MP2 gradient formula, in the DC manner; that is, the entire matrix is obtained as the sum of subsystem matrices masked by the partition matrix. Therefore, the method requires solving only the local Z-vector equations. Illustrative applications to three types of systems, peptides, Si surface model, and delocalized polyenes, reveal the effectiveness of the present method.
On the non-local heat kernel expansion
Authors: Codello Alessandro , Zanusso Omar
Published: January 2013

We propose a novel derivation of the non-local heat kernel expansion, first studied by Barvinsky, Vilkovisky, and Avramidi, based on simple diagrammatic equations satisfied by the heat kernel. For Laplace-type differential operators, we obtain the explicit form of the non-local heat kernel form factors to second order in the curvatures. Our method can be generalized easily to the derivation of the non-local heat kernel expansion of a wide class of differential operators.
Effects of reactant internal excitation and orientation on dissociative chemisorption of H2O on Cu(111): Quasi-seven-dimensional quantum dynamics on a refined potential energy surface
Authors: Jiang Bin , Li Jun , Xie Daiqian , Guo Hua
Published: January 2013

To understand the influence of reactant internal excitation and orientation on the dissociative chemisorption of water on Cu(111), a quasi-seven-dimensional quantum dynamics study has been carried out on a refined potential energy surface (PES). The new PES was modified in the asymptotic region to allow an accurate characterization of the H2O ro-vibrational levels. The mode selectivity of the reaction was reexamined on the new PES and found to be consistent with our earlier work. To rationalize the observed mode selectivity, a vibrationally adiabatic reaction path model was determined on this PES. Furthermore, the reactivity for various rotationally excited H2O was investigated. It is shown that even low rotational excitation in H2O can either enhance or inhibit the reaction and the reactivity depends on the orientation of the impinging molecule.
Photocarrier generation in CuxO thin films deposited by radio frequency sputtering
Authors: Viet Pham Thien , Rao Manohar , Andreasson P. , Peng Yuan , Wang Junling , Jinesh K. B.
Published: January 2013

Copper oxides (CuxO) thin films were deposited using radio frequency (RF) sputtering on glass substrates. By tuning the argon (Ar) partial pressure during deposition, cuprous oxide (Cu2O), cupric oxide (CuO), or their mixed phase could be achieved. Drastic variations in the Hall mobility, hole density, and resistivity of the samples were observed due to the presence of different phases in the films. Kelvin probe studies indicate that the photo-generated carriers have lower recombination rate in pure Cu2O phase. This was further validated by transient absorption measurements, where the estimated carrier lifetime for Cu2O was much larger that other phases.
Bihydrogel particles as free-standing mechanical pH microsensors
Authors: Tsou Tsung-Yen , Chen Hsien-Yeh , Hsieh Chih-Chen
Published: January 2013

We propose a bihydrogel mechanical microsensor made from two hydrogels with different sensitivity to the environment. The idea was used to create pH microsensors consisting of two parallel phases of crosslinked hydrogel in which only one phase is pH-sensitive. Working similarly to a bimetallic strip, the bihydrogel particle bends depending on the environmental pH. These freestanding bihydrogel particles are low-cost and easy to manufacture. They are particularly suitable for use in confined environment where most microsensors are unable to fit in. The same principle can also be used to create sensors for temperature, ionic strength, and other environmental parameters.
Effect of transition-metal additives on hydrogen desorption kinetics of MgH2
Authors: Roy Anindya , Janotti Anderson , Van de Walle Chris G.
Published: January 2013

Using first-principles calculations, we study the effect of transition-metal additives (Ti, Fe, Co, and Ni) on the rate of hydrogen desorption in MgH2. The presence of large concentrations of transition-metal impurities causes the Fermi level to shift according to the position of the transition-metal acceptor/donor levels in the band gap. This shift can lower the formation energy of native defects and increase their concentration. The resulting higher rates of hydrogen desorption enhance the prospect of MgH2 as a solid-state hydrogen-storage material.
High compressibility of rare earth-based bulk metallic glasses
Authors: Zhao W. , Wang Y. Y. , Liu R. P. , Li G.
Published: January 2013

The structural evolution of rare earth-based metallic glasses under high pressures at room temperature is investigated by X-ray diffraction synchrotron radiation. The high compressibility of rare earth-based bulk metallic glasses is found to be caused by transition from a low-density state to a high-density state under high pressures. This polyamorphic phase transition is achieved through the following: (1) smaller atoms are extruded into the clearance of the larger rare earth atoms; and (2) the volume of lanthanide elements collapses because of the delocalization of 4f electrons.
Non-rare earth white emission phosphor: Ti-doped MgAl2O4
Authors: Lim J. H. , Kim B. N. , Kim Y. , Kang S. , Xie R. J. , Chong I. S. , Morita K. , Yoshida H. , Hiraga K.
Published: January 2013

White emission produced by Ti-doped MgAl2O4 phosphor powder is reported, which is in contrast to blue emission from most Ti-doped single crystals of MgAl2O4. The white emission peak consists of four deconvoluted peaks: 440, 490, 550, and 620 nm, when was excited by 260 nm wavelength. Ti4+ in octahedral sites was found to contribute mostly to greenish blue emissions at 490 and 550 nm. The red emission at 620 nm was produced by abundant Mg2+ and O2− vacancies in the spinel powder.
Adaptation May Cause Some of the Face Caricature Effect
Authors: Hancock Peter J B , Little Anthony C
Published: January 2013

One of the ways to demonstrate a caricature preference is to ask participants to adjust a face image over a range from anti-caricature to caricature until it shows the best likeness to a specific individual. Since facial adaptation, whereby exposure to a face influences subsequent perception of faces, is rapid, it is possible that adaptation promotes the selection of a caricatured image. We tested whether giving participants a reference average face image, to counteract any adaptation, would reduce the degree of caricature selected for famous faces. Results confirmed a significant decrease but, even without an average, participants chose an anti-caricatured image. These data suggest a role for adaptation in generating caricature preferences while also suggesting such preferences are not inevitable.
Comparative costs, chemical treatments and flystrike rates in mulesed and unmulesed sheep flocks as predicted by a weather-driven model
Authors: Lucas Peri , Horton Brian
Published: January 2013

A computer model for flystrike risk was used to predict the expected costs, pesticide used and number of sheep struck, according to time of shearing and crutching, for the regions Flinders Island, Gunning and Inverell. A comparison was carried out between mulesed and unmulesed sheep and the program optimised the preventive chemical treatments required to minimise overall costs associated with flystrike and flock treatments. This study examined cost differences between mulesed and unmulesed hoggets and ewes where the only change in management was in the method and timing of pesticide treatment. The model indicated that unmulesed sheep would require more frequent treatment with longer lasting pesticides. Costs associated with flystrike were estimated to increase by $220 per thousand sheep per year (ewes) or $349 (hoggets) for Flinders Island, $445 or $512 (Gunning) and $363 or $844 (Inverell). For unmulesed sheep the model indicated that dicyclanil might be required rather than cyromazine to provide acceptable flystrike control at a lower cost. Despite this increase in preventive treatment for unmulesed sheep, the predicted number of struck sheep was higher for Gunning and Inverell, but not for Flinders Island, where the model did not always require routine preventive treatment for mulesed sheep. In regions with a flystrike problem, avoiding any increase in strike after ceasing to mules was estimated to double the cost of preventive measures for most shearing dates. The date of shearing had a significant effect on total costs related to flystrike and in some cases shearing during the fly season increased costs and increased strike by interfering with the most efficient use of preventive treatment. Crutching reduced costs in some cases, but in other situations the timing of crutching interfered with the optimum timing of chemical treatment and the model sometimes predicted worse outcomes than with no crutching. The timing of shearing, crutching and treatment must be carefully managed if both costs and the number of struck sheep are to be minimised. Control of flystrike was found to be most efficient when there was a single period of high risk of strike or two equal periods of strike risk, rather than one short and one long period.
Polyguanidine as a Highly Efficient and Reusable Catalyst for Knoevenagel Condensation Reactions in Water
Authors: Zhao Xian-Liang , Yang Ke-Fang , Liu Xuan-Gan , Ye Chun-Lin , Xu Li-Wen , Lai Guo-Qiao
Published: January 2013

Polyguanidine is used as a novel and highly efficient catalyst in the Knoevenagel reaction of aldehydes with active methylene compounds in water to afford substituted electrophilic alkenes. This method is applicable for a wide range of aldehydes including aromatic and heterocyclic substrates. The polyguanidine catalyst can be recovered by simple filtration and reused many times for the aqueous Knoevenagel reaction without loss of activity.
Pharmacological modulation of circadian rhythms by synthetic activators of the deacetylase SIRT1
Authors: Bellet Marina M. , Nakahata Yasukazu , Boudjelal Mohamed , Watts Emma , Mossakowska Danuta E. , Edwards Kenneth A. , Cervantes Marlene , Astarita Giuseppe , Loh Christine , Ellis James L. , Vlasuk George P. , Sassone-Corsi Paolo
Published: January 2013

Circadian rhythms govern a wide variety of physiological and metabolic functions in many organisms, from prokaryotes to humans. We previously reported that silent information regulator 1 (SIRT1), a NAD
+
-dependent deacetylase, contributes to circadian control. In addition, SIRT1 activity is regulated in a cyclic manner in virtue of the circadian oscillation of the coenzyme NAD
+
. Here we used specific SIRT1 activator compounds both in vitro and in vivo. We tested a variety of compounds to show that the activation of SIRT1 alters CLOCK:BMAL1-driven transcription in different systems. Activation of SIRT1 induces repression of circadian gene expression and decreases H3 K9/K14 acetylation at corresponding promoters in a time-specific manner. Specific activation of SIRT1 was demonstrated in vivo using liver-specific SIRT1-deficient mice, where the effect of SIRT1 activator compounds was shown to be dependent on SIRT1. Our findings demonstrate that SIRT1 can fine-tune circadian rhythm and pave the way to the development of pharmacological strategies to address a broad range of therapeutic indications.
Spatial mismatch between the Na
+
flux and spike initiation in axon initial segment
Authors: Baranauskas Gytis , David Yaron , Fleidervish Ilya A.
Published: January 2013

It is widely believed that, in cortical pyramidal cells, action potentials (APs) initiate in the distal portion of axon initial segment (AIS) because that is where Na
+
channel density is highest. To investigate the relationship between the density of Na
+
channels and the spatiotemporal pattern of AP initiation, we simultaneously recorded Na
+
flux and action currents along the proximal axonal length. We found that functional Na
+
channel density is approximately four times lower in the AP trigger zone than in the middle of the AIS, where it is highest. Computational analysis of AP initiation revealed a paradoxical mismatch between the AP threshold and Na
+
channel density, which could be explained by the lopsided capacitive load imposed on the proximal end of the AIS by the somatodendritic compartment. Favorable conditions for AP initiation are therefore achieved in the distal AIS portion, close to the edge of myelin, where the current source–load ratio is highest. Our findings suggest that cable properties play a central role in determining where the AP starts, such that small plastic changes in the local AIS Na
+
channel density could have a large influence on neuronal excitability as a whole.
Generous economic investments after basolateral amygdala damage
Authors: van Honk Jack , Eisenegger Christoph , Terburg David , Stein Dan J. , Morgan Barak
Published: January 2013

Contemporary economic models hold that instrumental and impulsive behaviors underlie human social decision making. The amygdala is assumed to be involved in social-economic behavior, but its role in human behavior is poorly understood. Rodent research suggests that the basolateral amygdala (BLA) subserves instrumental behaviors and regulates the central-medial amygdala, which subserves impulsive behaviors. The human amygdala, however, typically is investigated as a single unit. If these rodent data could be translated to humans, selective dysfunction of the human BLA might constrain instrumental social-economic decisions and result in more impulsive social-economic choice behavior. Here we show that humans with selective BLA damage and a functional central-medial amygdala invest nearly 100% more money in unfamiliar others in a trust game than do healthy controls. We furthermore show that this generosity is not caused by risk-taking deviations in nonsocial contexts. Moreover, these BLA-damaged subjects do not expect higher returns or perceive people as more trustworthy, implying that their generous investments are not instrumental in nature. These findings suggest that the human BLA is essential for instrumental behaviors in social-economic interactions.
A double-integration hypothesis to explain ocean ecosystem response to climate forcing
Authors: Di Lorenzo Emanuele , Ohman Mark D.
Published: January 2013

Long-term time series of marine ecological indicators often are characterized by large-amplitude state transitions that can persist for decades. Understanding the significance of these variations depends critically on the underlying hypotheses characterizing expected natural variability. Using a linear autoregressive model in combination with long-term zooplankton observations off the California coast, we show that cumulative integrations of white-noise atmospheric forcing can generate marine population responses that are characterized by strong transitions and prolonged apparent state changes. This model provides a baseline hypothesis for explaining ecosystem variability and for interpreting the significance of abrupt responses and climate change signatures in marine ecosystems.
DNA analysis of an early modern human from Tianyuan Cave, China
Authors: Fu Qiaomei , Meyer Matthias , Gao Xing , Stenzel Udo , Burbano Hernán A. , Kelso Janet , Pääbo Svante
Published: January 2013

Hominins with morphology similar to present-day humans appear in the fossil record across Eurasia between 40,000 and 50,000 y ago. The genetic relationships between these early modern humans and present-day human populations have not been established. We have extracted DNA from a 40,000-y-old anatomically modern human from Tianyuan Cave outside Beijing, China. Using a highly scalable hybridization enrichment strategy, we determined the DNA sequences of the mitochondrial genome, the entire nonrepetitive portion of chromosome 21 (∼30 Mbp), and over 3,000 polymorphic sites across the nuclear genome of this individual. The nuclear DNA sequences determined from this early modern human reveal that the Tianyuan individual derived from a population that was ancestral to many present-day Asians and Native Americans but postdated the divergence of Asians from Europeans. They also show that this individual carried proportions of DNA variants derived from archaic humans similar to present-day people in mainland Asia.
Diagnostic testing and treatment under ambiguity: Using decision analysis to inform clinical practice
Authors: Manski Charles F.
Published: January 2013

Partial knowledge of patient health status and treatment response is a pervasive concern in medical decision making. Clinical practice guidelines (CPGs) make recommendations intended to optimize patient care, but optimization typically is infeasible with partial knowledge. Decision analysis shows that a clinician’s objective, knowledge, and decision criterion should jointly determine the care he prescribes. To demonstrate, this paper studies a common scenario regarding diagnostic testing and treatment. A patient presents to a clinician, who obtains initial evidence on health status. The clinician can prescribe a treatment immediately or he can order a test yielding further evidence that may be useful in predicting treatment response. In the latter case, he prescribes a treatment after observation of the test result. I analyze this scenario in three steps. The first poses a welfare function and characterizes optimal care. The second describes partial knowledge of response to testing and treatment that might realistically be available. The third considers decision criteria. I conclude with reconsideration of clinical practice guidelines.
HSV carrying WT REST establishes latency but reactivates only if the synthesis of REST is suppressed
Authors: Zhou Guoying , Du Te , Roizman Bernard
Published: January 2013

Significance

HSV expresses numerous functions to suppress the host and replicate at body orifices and yet establishes silent, latent infections in sensory neurons. One hypothesis that addresses the apparent contradiction is that peripheral ganglia serve as barriers to the spread of viruses via neurons in the CNS and that HSV usurps these functions to establish a latent state. This report examines the role of the corepressor element-1 silencing transcription factor (CoREST)/REST repressor complex in establishment of latency and reactivation. Mirroring earlier studies showing that expression of dominant-negative REST suppresses latency and increases virulence, a WT REST inserted into the viral genome enables latency but blocks reactivation.
Mixed Metazoan and Bacterial Infection of the Gas Bladder of the Lined Seahorse—A Case Report
Authors: Anderson Paul A. , Petty Barbara D.
Published: January 2013

Five wild-caught Lined Seahorses Hippocampus erectus from an aquarium system presented with altered buoyancy and distended upper trunks. Radiography of one specimen revealed a reduced air volume in the gas bladder. Pneumocystocentesis revealed a brown exudate of numerous leukocytes, parasite ova, and Gram- and acid-fast-positive bacilli under wet mounts and stains. Necropsies revealed enlarged, friable kidneys and distended gas bladders containing copious purulent exudate, necrotic tissue, and adult digeneans Dictysarca virens. Bacterial isolates from exudate cultures grown on Lowenstein–Jensen medium were identified as Gordonia sp. and Mycobacterium poriferae by high-performance liquid chromatography and 16S ribosomal DNA sequencing. Histopathology demonstrated a histiocytic response in kidney and gas bladder exudate, inflammation of the gas bladder wall, and infection of the gas bladder lumen with parasite ova and acid-fast-positive and Gomori's methenamine silver-positive bacilli. Praziquantel is prescribed for digenean infections but dissolves incompletely in seawater and is toxic to this host. Eradication of intermediate host vectors is a management option. Treatment of Gordonia infection has not been addressed in nonhuman animals, and there is no known effective treatment for Mycobacterium spp. infection in fishes. This is the first case report of digenean infection of the gas bladder in a syngnathid, Gordonia sp. infection in a nonhuman animal, and M. poriferae infection in a fish.

Received May 25, 2012; accepted October 12, 2012
Stress Matters Revisited: A Boundary Change Experiment
Authors: Breen Mara , Clifton Charles
Published: January 2013

Breen and Clifton (Stress matters: Effects of anticipated lexical stress on silent reading. Journal of Memory and Language, 2011, 64, 153–170) argued that readers’ eye movements during silent reading are influenced by the stress patterns of words. This claim was supported by the observation that syntactic reanalysis that required concurrent metrical reanalysis (e.g., a change from the noun form of abstract to the verb form) resulted in longer reading times than syntactic reanalysis that did not require metrical reanalysis (e.g., a change from the noun form of report to the verb form). However, the data contained a puzzle: The disruption appeared on the critical word ( abstract, report) itself, although the material that forced the part of speech change did not appear until the next region. Breen and Clifton argued that parafoveal preview of the disambiguating material triggered the revision and that the eyes did not move on until a fully specified lexical representation of the critical word was achieved. The present experiment used a boundary change paradigm in which parafoveal preview of the disambiguating region was prevented. Once again, an interaction was observed: Syntactic reanalysis resulted in particularly long reading times when it also required metrical reanalysis. However, now the interaction did not appear on the critical word, but only following the disambiguating region. This pattern of results supports Breen and Clifton's claim that readers form an implicit metrical representation of text during silent reading.
Seasonal Influenza and Tdap Vaccination Policies in Michigan Hospitals Progress Yet Substantial Capacity to Improve
Authors: Carlton Cristi A. , Sienko Dean G. , Vranesich Patricia A.
Published: January 2013

We determined the prevalence of mandatory influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination policies for staff in Michigan hospitals and factors affecting policy implementation. Forty-one percent of responders reported a mandatory influenza vaccination policy, and 11% reported a mandatory Tdap vaccination policy. The support of hospital leadership is critical to policy implementation and overcoming barriers.
Quantifying the tradeoff between precaution and yield in fishery reference points
Authors: Hart Deborah R.
Published: January 2013

Hart, D. R. 2013. Quantifying the tradeoff between precaution and yield in fishery reference points. – ICES Journal of Marine Science, 70: 591–603. A method using Monte Carlo simulations for estimating fishery reference points that accounts for parameter uncertainty is presented. Uncertainties in the input parameters of yield-per-recruit and stock-recruit analyses are propagated to estimate uncertainty in reference points such as FMSY. These uncertainties are used to evaluate the tradeoffs between the risks of overfishing and stock collapse, and the cost of reduced expected yield due to setting fishing mortality below FMSY. At fishing mortalities near FMSY, reduction in fishing mortality substantially decreases the probability of overfishing and stock collapse in exchange for slightly reduced expected yield. At lower fishing mortality rates, the marginal benefit (in terms of lessened risk of overfishing and stock collapse) from further reductions in fishing mortality is less, and the cost in forgone yield is greater. Less resilient “low steepness” stocks require additional precaution due to the risk of complete population collapse. Marine protected areas can also reduce risks of collapse, but at a higher cost in terms of expected yield than effort reduction. Implementation uncertainty (i.e. uncertainty in achieving a fishing mortality target) increases the risk of overfishing as well the loss of yield due to precaution, except at fishing mortalities near or above FMSY.
Overexpression of the Trehalase Gene AtTRE1 Leads to Increased Drought Stress Tolerance in Arabidopsis and Is Involved in Abscisic Acid-Induced Stomatal Closure
Authors: Van Houtte Hilde , Vandesteene Lies , López-Galvis Lorena , Lemmens Liesbeth , Kissel Ewaut , Carpentier Sebastien , Feil Regina , Avonce Nelson , Beeckman Tom , Lunn John E. , Van Dijck Patrick
Published: January 2013

Introduction of microbial trehalose biosynthesis enzymes has been reported to enhance abiotic stress resistance in plants but also resulted in undesirable traits. Here, we present an approach for engineering drought stress tolerance by modifying the endogenous trehalase activity in Arabidopsis (Arabidopsis thaliana). AtTRE1 encodes the Arabidopsis trehalase, the only enzyme known in this species to specifically hydrolyze trehalose into glucose. AtTRE1-overexpressing and Attre1 mutant lines were constructed and tested for their performance in drought stress assays. AtTRE1-overexpressing plants had decreased trehalose levels and recovered better after drought stress, whereas Attre1 mutants had elevated trehalose contents and exhibited a drought-susceptible phenotype. Leaf detachment assays showed that Attre1 mutants lose water faster than wild-type plants, whereas AtTRE1-overexpressing plants have a better water-retaining capacity. In vitro studies revealed that abscisic acid-mediated closure of stomata is impaired in Attre1 lines, whereas the AtTRE1 overexpressors are more sensitive toward abscisic acid-dependent stomatal closure. This observation is further supported by the altered leaf temperatures seen in trehalase-modified plantlets during in vivo drought stress studies. Our results show that overexpression of plant trehalase improves drought stress tolerance in Arabidopsis and that trehalase plays a role in the regulation of stomatal closure in the plant drought stress response.
SlARF4, an Auxin Response Factor Involved in the Control of Sugar Metabolism during Tomato Fruit Development
Authors: Sagar Maha , Chervin Christian , Mila Isabelle , Hao Yanwei , Roustan Jean-Paul , Benichou Mohamed , Gibon Yves , Biais Benoît , Maury Pierre , Latché Alain , Pech Jean-Claude , Bouzayen Mondher , Zouine Mohamed
Published: January 2013

Successful completion of fruit developmental programs depends on the interplay between multiple phytohormones. However, besides ethylene, the impact of other hormones on fruit quality traits remains elusive. A previous study has shown that down-regulation of SlARF4, a member of the tomato (Solanum lycopersicum) auxin response factor (ARF) gene family, results in a dark-green fruit phenotype with increased chloroplasts (Jones et al., 2002). This study further examines the role of this auxin transcriptional regulator during tomato fruit development at the level of transcripts, enzyme activities, and metabolites. It is noteworthy that the dark-green phenotype of antisense SlARF4-suppressed lines is restricted to fruit, suggesting that SlARF4 controls chlorophyll accumulation specifically in this organ. The SlARF4 underexpressing lines accumulate more starch at early stages of fruit development and display enhanced chlorophyll content and photochemical efficiency, which is consistent with the idea that fruit photosynthetic activity accounts for the elevated starch levels. SlARF4 expression is high in pericarp tissues of immature fruit and then undergoes a dramatic decline at the onset of ripening concomitant with the increase in sugar content. The higher starch content in developing fruits of SlARF4 down-regulated lines correlates with the up-regulation of genes and enzyme activities involved in starch biosynthesis, suggesting their negative regulation by SlARF4. Altogether, the data uncover the involvement of ARFs in the control of sugar content, an essential feature of fruit quality, and provide insight into the link between auxin signaling, chloroplastic activity, and sugar metabolism in developing fruit.
FIRM HETEROGENEITY, RULES OF ORIGIN, AND RULES OF CUMULATION*
Authors: Bombarda Pamela , Gamberoni Elisa
Published: January 2013

This article sheds light on the restrictive nature of rules of origin (ROO) and on the role of diagonal cumulation in mitigating the protectionist content of ROO. Empirical evidence suggests that diagonal cumulation has beneficial effects on trade—particularly among spoke countries. We show that these patterns can be reconciled with a theoretical setting where heterogeneous firms buy intermediate inputs from domestic and foreign sources. The model finds that switching from bilateral to diagonal cumulation relaxes the restrictiveness of the ROO and leads the least productive exporters to stop exporting.
Xiphion heracleanum sp. nov. (Iridaceae) from Morocco
Authors: Rodríguez Jorge Martínez , Crespo Manuel B.
Published: January 2013

As a part of the revision of Xiphion (Iris subg. Xiphion) for the ‘Flora Iberica’ project, some material collected in the 19th and 20th centuries in the Tangiers area (northern Morocco) was found impossible to assign to any of the known taxa in the genus. In part, they resembled X. junceum and X. rutherfordii, but showed a peculiar combination of vegetative and floral characters which to date is exclusive. Accordingly, the new species X. heracleanum Mart. Rodr. & M. B. Crespo is described for these plants, and evidence is reported to justify the adopted treatment. Relationships to other taxa in the genus are also discussed, and the new combination X. rutherfordii (Mart. Rodr., P. Vargas, M. Carine & Jury) Mart. Rodr. & M. B. Crespo comb. nov. is provided.
Computational Modeling of the Effects of Viscous Dissipation on Polymer Melt Flow Behavior During Injection Molding Process in Plane Channels
Authors: Tutar M. , Karakus A.
Published: January 2013

The present finite volume method based fluid flow solutions investigate the boundary-layer flow and heat transfer characteristics of polymer melt flow in a rectangular plane channel in the presence of the effect of viscous dissipation and heat transfer by considering the viscosity and density variations in the flow. For different inflow velocity boundary conditions and the injection polymer melt temperatures, the viscous dissipation effects on the velocity and temperature distributions are studied extensively to analyze the degree of interactions of thermal flow field dominated by the viscous heating and momentum diffusion mechanism with varying boundary conditions. The modified forms of Cross constitutive equation and Tait equation of state are adopted for the representation of viscosity variations and density change, respectively, in the polymer melt flow. These models together with the viscous dissipation terms are successfully incorporated into the finite volume method based fluid flow solutions to realistically represent the heat effects in the plane channel. The numerical results presented for two different commercial polymer melt flows, namely, polymer Polyacetal POM-M90-44 and polypropylene (PP), demonstrate that proposed mathematical formulations for viscosity and density variations including viscous heating terms into the energy equations, which are fully coupled with momentum equations, lead to more accurate representation of the fluid flow and heat transfer phenomena for the polymer melt flows in plane channels.
The Mechanism of the Initiation and Progression of Glioma
Authors: Puri Ishwar K. , Elankumaran Subbiah , Biswas Moanaro , Li Liwu
Published: January 2013

The fate of malignant glioma (MG) is governed by a multifaceted and dynamic circuit that involves the surrounding cellular and molecular tumor microenvironment. Despite extensive experimental studies, a complete understanding of the complex interactions among the constituents of this microenvironment remains elusive. To clarify this, we introduce a biologically based mathematical model that examines the dynamic modulation of glioma cancer stem cells (GSC) by different immune cell types and intracellular signaling pathways. It simulates the proliferation of glioma stem cells due to macrophage-induced inflammation, particularly involving two microglia phenotypes. The model can be used to regulate therapies by monitoring the GSC self-renewal rates that determine tumor progression. We observe that the GSC population is most sensitive to its own proliferation rate and the relative levels of the activating natural killer (NK) cell stimulatory receptors (NKG2D) versus killer inhibitory receptors (KIR) on NK cells that influence the proliferation or demise of the GSC population. Thus, the two most important factors involved in tumorigenesis or tumor regression are (1) GSC proliferation and (2) the functional status of NK cells. Therefore, strategies aimed at blocking proliferation and enhancing NKG2D and KIR signals should have a potentially beneficial impact for treating malignant gliomas.
Effective Electromechanical Properties of 622 Piezoelectric Medium With Unidirectional Cylindrical Holes
Authors: Roberto Aguiar Adair , Bravo Castillero Julián , Rodríguez Ramos Reinaldo , Paulo da Silva Uziel
Published: January 2013

The asymptotic homogenization method (AHM) yields a two-scale procedure to obtain the effective properties of a composite material containing a periodic distribution of unidirectional circular cylindrical holes in a linear transversely isotropic piezoelectric matrix. The matrix material belongs to the symmetry crystal class 622. The holes are centered in a periodic array of cells of square cross sections and the periodicity is the same in two perpendicular directions. The composite state is antiplane shear piezoelectric, that is, a coupled state of out-of-plane shear deformation and in-plane electric field. Local problems that arise from the two-scale analysis using the AHM are solved by means of a complex variable method. For this, the solutions are expanded in power series of Weierstrass elliptic functions, which contain coefficients that are determined from the solutions of infinite systems of linear algebraic equations. Truncating the infinite systems up to a finite, but otherwise arbitrary, order of approximation, we obtain analytical formulas for effective elastic, piezoelectric, and dielectric properties, which depend on both the volume fraction of the holes and an electromechanical coupling factor of the matrix. Numerical results obtained from these formulas are compared with results obtained by the Mori–Tanaka approach. The results could be useful in bone mechanics.
Wave transmission through periodic, quasiperiodic, and random one-dimensional finite lattices
Authors: Gutiérrez-Medina Braulio
Published: January 2013

The quantum mechanical transmission probability is calculated for one-dimensional finite lattices with three types of potentials: periodic, quasiperiodic, and random. When the number of lattice sites included in the computation is systematically increased, distinct features in the transmission probability vs. energy diagrams are observed for each case. The periodic lattice gives rise to allowed and forbidden transmission regions that correspond to the energy band structure of the infinitely periodic potential. In contrast, the transmission probability diagrams for both quasiperiodic and random lattices show the absence of well-defined band structures and the appearance of wave localization effects. Using the average transmissivity concept, we show the emergence of exponential (Anderson) and power-law bounded localization for the random and quasiperiodic lattices, respectively.
Reinventing the wheel: The chaotic sandwheel
Authors: Tongen Anthony , Thelwell Roger J. , Becerra-Alonso David
Published: January 2013

The Malkus chaotic waterwheel, a tool to mechanically demonstrate Lorenzian dynamics, motivates the study of a chaotic sandwheel. We model the sandwheel in parallel with the waterwheel when possible, noting where methods may be extended and where no further analysis seems feasible. Numerical simulations are used to compare and contrast the behavior of the sandwheel with the waterwheel. Simulations confirm that the sandwheel retains many of the elements of chaotic Lorenzian dynamics. However, bifurcation diagrams show dramatic differences in where the order-chaos-order transitions occur.
Why do bubbles in Guinness sink?
Authors: Benilov E. S. , Cummins C. P. , Lee W. T.
Published: January 2013

Stout beers show the counter-intuitive phenomena of sinking bubbles, while the beer is settling. Previous research suggests that this phenomenon is due to the small size of the bubbles in these beers and the presence of a circulatory current, directed downwards near the side of the wall and upwards in the interior of the glass. The mechanism by which such a circulation is established and the conditions under which it will occur has not been clarified. In this paper, we use simulations and experiments to demonstrate that the flow in a glass of stout beer depends on the shape of the glass. If it narrows downwards (as the traditional stout glass, the pint, does), the flow is directed downwards near the wall and upwards in the interior and sinking bubbles will be observed. If the container widens downwards, the flow is opposite to that described above and only rising bubbles will be seen.
New insights into student understanding of complete circuits and the conservation of current
Authors: Stetzer MacKenzie R. , van Kampen Paul , Shaffer Peter S. , McDermott Lillian C.
Published: January 2013

The research reported in this paper represents an in-depth examination of the finding from an earlier investigation that university students often do not develop a functional understanding of the concept of a complete circuit. Participants in this study included undergraduates in introductory and upper-division physics courses as well as graduate teaching assistants. Although the concept of a complete circuit is covered in the standard undergraduate curriculum, students in all three groups had difficulty in applying this concept to single-loop, resistive circuits. Students frequently did not apply the conservation of current when analyzing circuits containing more than one battery. Certain basic conceptual difficulties spanned all of the populations and even persisted after instruction in upper-division courses that involved analog electronics.