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Vocal repertoire of the New Zealand kea parrot Nestor notabilis

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Current Zoology 2012年第5期58卷 727-740页

作者： Raoul SCHWING stuart PARSONS Ximena J. NELSON School of Biological Sciences University of Auckland Private Bag 92019 Auckland New Zealand School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch New Zealand

The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com- munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand＇s Southern Alps. Based on audio and visual spectrographic differences, these calls were categorised into seven distinct call types： the non-oscillating ＇screech＇ contact call and ＇mew＇; and the oscillating ＇trill＇, ＇chatter＇, ＇warble＇ and ＇whistle＇; and a hybrid ＇screech-trill＇. Most of these calls contained aspects that were individually unique, in addition to potentially encoding for an individual＇s sex and age. Additionally, for each recording, the sender＇s previous and next calls were noted, as well as any response given by conspecifics. We found that the previous and next calls made by the sender were most often of the same type, and that the next most likely pre- ceding and/or following call type was the screech call, a contact call which sounds like the ＇kee-ah＇ from which the bird＇s name derives. As a social bird capable of covering large distances over visually obstructive terrain, long distance contact calls may be of considerable importance for social cohesion. Contact calls allow kea to locate conspecifics and congregate in temporary groups for social activities. The most likely response to any given call was a screech, usually followed by the same type of call as the ini- tial call made by the sender, although responses differed depending on the age of the caller. The exception was the warble, the kea＇s play call, to which the most likely response was another warble. Being the most common call type, as well as the default response to another call, it appears that the ＇contagious＇ screech contact call plays a central role in kea vocal communication and social cohesion [Current Zoology 58 （5）： 727-740, 2012].

关键词： Acoustic signals Communication Kea Psittacidae Social behaviour Habitat

Laser enhanced gettering of silicon substrates

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Frontiers in Energy 2017年第1期11卷 23-31页

作者： Daniel CHEN Matthew EDWARDS stuart WENHAM Malcolm ABBOTT Brett HALLAM School of Photovoltaic and Renewable Energy Engineering University of New South Wales Kensington NSW 2052 Australia

One challenge to the use of lightly-doped, high efficiency emitters on multicrystalline silicon wafers is the poor gettering efficiency of the diffusion processes used to fabricate them. With the photovoltaic industry highly reliant on heavily doped phosphorus diffusions as a source of gettering, the transition to selective emitter structures would require new alternative methods of impurity extraction. In this paper, a novel laser based method for gettering is investigated for available silicon wafers used its impact on commercially in the manufacturing of solar cells. Direct comparisons between laser enhanced gettering （LasEG） and lightly-doped emitter diffusion gettering demonstrate a 45% absolute improvement in bulk minority carrier lifetime when using the laser process. Although grain boundaries can be effective gettering sites in multicrystalline wafers, laser processing can substantially improve the performance of both grain boundary sites and intra-grain regions. This improvement is correlated with a factor of 6 further decrease in interstitial iron concentra- tions. The removal of such impurities from multicrystalline wafers using the laser process can result in intra-grain enhancements in implied open-circuit voltage of up to 40 mV. In instances where specific dopant profiles are required for a diffusion on one surface of a solar cell, and the diffusion process does not enable effective gettering, LasEG may enable improved gettering during the diffusion process.

关键词： gettering multicystaline silicon impurities,laser doping

A Fractional Micro-Macro Model for Crowds of Pedestrians Based on Fractional Mean Field Games

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IEEE/CAA Journal of Automatica Sinica 2016年第3期3卷 261-270页

作者： Kecai Cao Yang Quan Chen Daniel stuart College of Automation Nanjing University of Posts and Telecommunications IEEE Mechatronics Embedded Systems and Automation Lab School of Engineering University of California Department of Electrical and Computer Engineering Utah State University

Modeling a crowd of pedestrians has been considered in this paper from different aspects. Based on fractional microscopic model that may be much more close to reality, a fractional macroscopic model has been proposed using conservation law of mass. Then in order to characterize the competitive and cooperative interactions among pedestrians, fractional mean field games are utilized in the modeling problem when the number of pedestrians goes to infinity and fractional dynamic model composed of fractional backward and fractional forward equations are constructed in macro scale. Fractional micromacro model for crowds of pedestrians are obtained in the end. Simulation results are also included to illustrate the proposed fractional microscopic model and fractional macroscopic model, respectively. © 2014 Chinese Association of Automation.

关键词： Control systems Electrical engineering

Case-control study of factors that trigger inflammatory bowel disease flares

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World Journal of Gastroenterology 2014年第15期20卷 4329-4334页

作者： Linda A Feagins Ramiz Iqbal stuart J Spechler VA North Texas Healthcare System DallasTX 75216United States Division of Gastroenterology University of Texas Southwestern Medical CenterDallasTX 75216United States

AIM: To explore the association between inflammatory bowel diseases (IBD) flares and potential triggers.

关键词： Inflammatory bowel diseases, Flare, Non-adherence, Crohn’ s disease, Ulcerative colitis

WEAK ERROR ESTIMATES FOR TRAJECTORIES OF SPDEs UNDER SPECTRAL GALERKIN DISCRETIZATION

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Journal of Computational Mathematics 2018年第2期36卷 159-182页

作者： Charles-Edouard Brehier Martin Hairer Andrew M. stuart Univ Lyon CNRS Universite Claude Bernard Lyon 1 UMR5208 Institut Camille Jordan F-69622 Villeurbanne France Department of Mathematics Imperial College London London SW7 2AZ UK Computing and Mathematical Sciences California Institute of Technology 1200 E. California Blvd. MC 305-16 Pasadena CA 91125 USA

We consider stochastic semi-linear evolution equations which are driven by additive, spatially correlated, Wiener noise, and in particular consider problems of heat equation （analytic semigroup） and damped-driven wave equations （bounded semigroup） type. We discretize these equations by means of a spectral Galerkin projection, and we study the approximation of the probability distribution of the trajectories： test functions are regular, but depend on the values of the process on the interval [0, T]. We introduce a new approach in the context of quantative weak error analysis for discretization of SPDEs. The weak error is formulated using a deterministic function （It6 map） of the stochastic convolution found when the nonlinear term is dropped. The regularity properties of the It6 map are exploited, and in particular second-order Taylor expansions employed, to transfer the error from spectral approximation of the stochastic convolution into the weak error of interest. We prove that the weak rate of convergence is twice the strong rate of convergence in two situations. First, we assume that the covariance operator commutes with the generator of the semigroup： the first order term in the weak error expansion cancels out thanks to an independence property. Second, we remove the commuting assumption, and extend the previous result, thanks to the analysis of a new error term depending on a commutator.

关键词： Stochastic Partial Differential Equations Weak approximation Spectral Galerkin discretization

Diagenetic and geochemical studies of the Buchan Formation (Upper Devonian) in the Central North Sea

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Petroleum Science 2018年第2期15卷 211-229页

作者： Long-Xun Tang Jon Gluyas stuart Jones Leon Bowen Department of Earth Sciences Durham University Department of Physics Durham University

The Upper Devonian Buchan Formation reservoirs in the UK Central North Sea are litharenite/sublitharenite and were deposited in fluvial-aeolian settings. The grain-coating clays in the aeolian sandstones have effectively inhibited quartz overgrowth. Hence, the reduction of reservoir quality is mainly due to mechanical compaction and early dolomite pre- cipitation in both fluvial and aeolian sandstones; quartz overgrowth and kaolinite illitization in fluvial sandstones; and limited smectite illitization in aeolian sandstones. The carbon/oxygen stable isotopes of dolomite cements suggest a predominantly marine carbon source and precipitation temperatures between 25 and 58 ~C indicating a shallow burial depth during dolomite precipitation. The temperatures and the dolomite distribution indicate that the cements originated from the overlying Upper Permian Zechstein carbonates. Extensive quartz overgrowths formed at 80 and 120 ~C in the late and deep diagenetic burial history. The most probable silica source was from feldspar kaolinitization and pressure dissolution of quartz grains. Through detailed petrography and geochemical analyses, the burial-paragenesis-thermal history of the Buchan Formation has been constructed. Similar diagenetic processes are likely to have occurred in the Buchan Formation in other parts of the Central and Northern North Sea. This study may allow new petroleum plays to be considered in areas previously thought to have poor hydrocarbon potential.

关键词： Buchan Formation Upper Devonian Central North Sea Sandstone diagenesis Geochemistry methods

Current endoscopic approach to indeterminate biliary strictures

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World Journal of Gastroenterology 2012年第43期18卷 6197-6205页

作者： David W Victor stuart Sherman Tarkan Karakan Mouen A Khashab Department of Medicine Johns Hopkins Hospital Baltimore MD 21287 United States Department of Medicine Indiana University School of Medicine Indianapolis IN 46202 United States Department of Medicine Gazi University 06710 Ankara Turkey

Biliary strictures are considered indeterminate when basic work-up, including transabdominal imaging and endoscopic retrograde cholangiopancreatography with routine cytologic brushing, are non-diagnostic. Indeterminate biliary strictures can easily be mischaracterized which may dramatically affect patient's outcome. Early and accurate diagnosis of malignancy impacts not only a patient's candidacy for surgery, but also potential timely targeted chemotherapies. A significant portion of patients with indeterminate biliary strictures have benign disease and accurate diagnosis is, thus, paramount to avoid unnecessary surgery. Current sampling strategies have suboptimal accuracy for the diagnosis of malignancy. Emerging data on other diagnostic modalities, such as ancillary cytology techniques, single operator cholangioscopy, and endoscopic ultrasonography-guided fine needle aspiration, revealed promising results with much improved sensitivity.

关键词： Indeterminate stricture Bile duct Single operator cholangioscope Cholangioscopy Endoscopic ultrasound Endoscopic retrograde cholangiopancrea-tography Bile duct stricture Indeterminate biliary stricture Confocal microscopy Transpapillary biopsy Cholangiocarcinoma Primary sclerosing cholangitis Spyglass

SmallSat swarm gravimetry:Revealing the interior structure of asteroids and comets

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Astrodynamics 2021年第3期5卷 217-236页

作者： William Gordon Ledbetter Rohan Sood James Keane Jeffrey stuart Astrodynamics and Space Research Laboratory The University of AlabamaTuscaloosaAL 35487USA Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA

A growing interest in small body exploration has motivated research into the rapid char-acterization of near-Earth objects to meet economic or scientific ***,knowledge of the internal density structure can aid with target selection and enables an understanding of prehistoric planetary formation to be *** this end,multi-layer extensions to the polyhedral gravity model are suggested,and an inversion technique is implemented to present their ***-orbit gravity gradiometry is simulated and employed in stochastic and deterministic algorithms,with results that imply robustness in both cases.

关键词： gravimetry asteroid exploration astrodynamics stochastic optimization

Disaster Risk Reduction in Cameroon: Are Contemporary Disaster Management Frameworks Accommodating the Sendai Framework Agenda 2030?

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International Journal of Disaster Risk Science 2019年第4期10卷 462-477页

作者： Henry Ngenyam Bang Lee stuart Miles Richard Duncan Gordon Disaster Management Centre Bournemouth UniversityDorsetTalbot CampusFern BarrowPoole BH125BBUK

Many African countries are prone to numerous hazardous events,exacerbated by the vulnerability of their rapidly increasing population and leading to frequent disasters that often have dire fiscal and development ***,there is declining sensitivity to these risks,contrary to the conventional wisdom of disaster management(DM)*** primary aim of this research is to understand the constraints and/or challenges limiting the ability of contemporary African DM systems/institutional frameworks from implementing adequate disaster risk reduction(DRR)*** a qualitative,case study based research strategy,this research investigates resistance to the effective implementation of DM/DRR within Cameroon’s contemporary DM system by using the Sendai Framework for Disaster Risk Reduction 2015–2030 guiding principles for DRR as *** findings reveal the existence of resistance factors that particularly complicate the communication,decision making,and coordination of DRR activities,the provision of resources,aspects of international assistance,as well as DRR planning and *** authors argue that such resistance factors contribute to making Cameroon’s DM system more reactive and further undermine risk *** article concludes by offering key recommendations that have the potential to alleviate the identified resistance factors as well as strengthen Cameroon’s DM,particularly in relation to capacity building,training,research development,and organizational resilience.

关键词： Cameroon Communication resistance Disaster management Disaster management system Disaster risk reduction West Africa