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Exploiting a metal wire grating in total internal reflection geometry to achieve achromatic polarization conversion

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Photonics Research 2017年第4期5卷 299-304页

作者： XUDONG LIU XUEQUAN CHEN EDWARD P.J.PARROTT emma PICKWELL-mACPHERSON Department of Electronic Engineering Chinese University of Hong Kong

We demonstrate how a metal wire grating can work as a 45° polarization converter, a quarter-wave retarder, and a half-wave retarder over a broadband terahertz range when set up in total internal reflection geometry. Classical electromagnetic theory is applied to understand the mechanism, and equations to calculate the polarization state of reflected light are derived. We use a metal grating with a period of 20 μm and width of 10 μm on a fused silica surface: linearly polarized terahertz light incident from fused silica with a supercritical incident angle of 52° is totally reflected by the metal grating and air. The polarization of the terahertz light is rotated by 45°, 90°, and circularly polarized by simply rotating the wire grating. The performance is achromatic over the measured range of 0.1–0.7 THz and comparable to commercial visible light wave retarders.

关键词： THz

Social interactivity in pigeon courtship behavior

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Current Zoology 2017年第1期63卷 85-95页

作者： emma L.R. WARE Daniel R. SAUNDERS Nikolaus F, TROJE Department of Psychology Queen's University Kingston Ontario K7L 3N6 Canada Centre for Neuroscience Studies Queen's University Kingston Ontario K7L 3N6 Canada Wellesley Institute Toronto Ontario M4V 3B Canada Centre for Brain/mind Sciences University of Trento Trento Italy Department of Biology Queen's University Kingston K7L 3N6 Canada

A closed-loop teleprompter system was used to isolate and manipulate social interactivity in thenatural courtship interactions of pigeons Columbia livia. In Experiment 1, a live face-to-face real-time interaction between 2 courting pigeons （Live） was compared to a played back version of thevideo stimulus recorded during the pairs Live interaction. We found that pigeons were behavinginteractively; their behavior depended on the relationships between their own signals and those oftheir partner. In Experiment 2, we tested whether social interactivity relies on spatial cues presentin the facing direction of a partner＇s display. By moving the teleprompter camera 90~ away from itsoriginal location, the partner＇s display was manipulated to appear as if it is directed 90~ away fromthe subject. We found no effect of spatial offset on the pigeon＇s behavioral response. In Experiment3, 3 time delays, 1 s, 3s, and 9s, a Live condition, and a playback condition were chosen to investi-gate the importance of temporal contiguity in social interactivity. Furthermore, both opposite-sex（courtship） and same-sex （rivalry） pairs were studied to investigate whether social-context affectssocial interactivity sensitivity. Our results showed that pigeon courtship behavior is sensitive totemporal contiguity. Behavior declined in the 9 s and Playback conditions as compared to Live con-dition and the shorter time delays. For males only, courtship behavior also increased in the 3-sdelay condition. The effect of social interactivity and time delay was not observed in rivalry inter-actions, suggesting that social interactivity may be specific to courtship.

关键词： courtship behavior, pigeons, social interactivity, spatial offset, time delay, video playback.

mercury photoreduction and photooxidation in lakes：Effects of filtration and dissolved organic carbon concentration

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Journal of Environmental Sciences 2018年第6期30卷 151-159页

作者： Nelson J.O’Driscoll emma Vost Erin mann Sara Klapstein Robert Tordon matthew Lukeman Department of Earth & Environmental Science Acadia University Wolfville B4P 2R6 Nova Scotia Canada Environment Canada Dartmouth Nova Scotia Canada Department of Chemistry Acadia University Wolfville B4P 2R6 Nova Scotia Canada

mercury is a globally distributed, environmental contaminant. Quantifying the retention and loss of mercury is integral for predicting mercury-sensitive ecosystems. There is little information on how dissolved organic carbon（DOC） concentrations and particulates affect mercury photoreaction kinetics in freshwater lakes. To address this knowledge gap,samples were collected from ten lakes in Kejimkujik National Park, Nova Scotia（DOC： 2.6–15.4 mg/L）. Filtered（0.2 μm） and unfiltered samples were analysed for gross photoreduction, gross photooxidation, and net reduction rates of mercury using pseudo first-order curves. Unfiltered samples had higher concentrations（p = 0.04） of photoreducible divalent mercury（Hg（II）RED）（mean of 754 ± 253 pg/L） than filtered samples（mean of 482 ± 206 pg/L）;however, gross photoreduction and photooxidation rate constants were not significantly different in filtered or unfiltered samples in early summer. DOC was not significantly related to gross photoreduction rate constants in filtered（R2= 0.43; p = 0.08） and unfiltered（R2= 0.02; p = 0.71） samples; DOC was also not significantly related to gross photooxidation rate constants in filtered or unfiltered samples. However, DOC was significantly negatively related with Hg（Ⅱ）RED in unfiltered（R2= 0.53; p = 0.04）, but not in filtered samples（R2= 0.04;p = 0.60）. These trends indicate that DOC is a factor in determining dissolved mercury photoreduction rates and particles partially control available Hg（Ⅱ）RED in lake water. This research also demonstrates that within these lakes gross photoreduction and photooxidation processes are close to being in balance. Changes to catchment inputs of particulate matter and DOC may alter mercury retention in these lakes and could partially explain observed increases of mercury accumulation in biota.

关键词： mercury Photoreduction Photooxidation Dissolved organic carbon(DOC) Particulates Kejimkujik National Park

Smelling fit： scent marking exposes parasitic infection status in the banded mongoose

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Current Zoology 2017年第3期63卷 237-247页

作者： Jessica mITCHELL michael A. CANT emma I.K. VITIKAINEN Hazel J. NICHOLS School of Natural Sciences and Psychology Liverpool John Moores University Liverpool L3 AF UK Centrefor Ecology and Conservation University of Exeter Penryn Campus TRIO 9FE UK

Preference for uninfected mates is presumed beneficial as it minimizes one's risk of contracting an infection and infecting one's offspring. In avian systems, visual ornaments are often used to indicate parasite burdens and facilitate mate choice. However, in mammals, olfactory cues have been proposed to act as a mechanism allowing potential mates to be discriminated by infection status. The effect of infection upon mammalian mate choice is mainly studied in captive rodents where experimental trials support preference for the odors of uninfected mates and some data suggest scent marking is reduced in individuals with high infection burdens. Nevertheless, whether such effects occur in nonmodel and wild systems remains poorly understood. Here, we investigate the interplay between parasite load (estimated using fecal egg counts) and scent marking behavior in a wild population of banded mongooses . Focusing on a costly protozoan parasite of the genus and the nematode worm , we first show that banded mongooses that engage in frequent, intensive scent marking have lower loads, suggesting marking behavior may be an indicator trait regarding infection status. We then use odor presentations to demonstrate that banded mongooses mark less in response to odors of opposite sexed individuals with high and loads. As both of these parasites are known to have detrimental effects upon the health of preweaned young in other species, they would appear key targets to avoid during mate choice. Results provide support for scent as an important ornament and mechanism for advertising parasitic infection within wild mammals.

关键词：寄生虫感染气味标记猫鼬哺乳动物野生种群配偶选择等孢球虫啮齿类动物

Assessing vulnerability to panic:a systematic review of psychological and physiological responses to biological challenges as prospective predictors of panic attacks and panic disorder

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General Psychiatry 2019年第6期32卷 297-303页

作者： Donald J Robinaugh meredith J Ward emma R Toner mackenzie L Brown Olivia m Losiewicz Eric Bui Scott P Orr Department of Psychiatry Massachusetts General HospitalBostonMassachusettsUSA Department of Psychiatry Harvard Medical SchoolBostonMassachusettsUSA

Background Cognitive-behavioural theories of panic disorder posit that panic attacks arise from a positive feedback loop between arousal-related bodily sensations and perceived *** a recently develope computational model formalising these theories of pani attacks,it was observed that the response to a simulate perturbation to arousal provided a strong indicator of vulnerability to panic attacks and panic *** this/review,we evaluate whether this observation is borne o in the empirical literature that has examined responses biological challenge(eg,C02 inhalation)and their relatio to subsequent panic attacks and panic *** We searched Pubmed,Web of Science and PsycINFO using keywords denoting provocation agents(eg,sodium lactate)and procedures(eg,infusion)combined with keywords relevant to panic disorder(eg,panic).Articles were eligible if they used response to a biologic challenge paradigm to prospectively predict panic attac or panic *** We identified four eligible *** effect sizes suggest that there is biological challenge response a moderate prospective association with subsequent pani attacks,but no prospective relationship with panic disorde Conclusions These findings provide support for the prediction derived from cognitive-behavioural theories an some preliminary evidence that response to a biological challenge may have clinical utility as a marker of vulnerab to panic attacks pending further research and developme Trial registration number 135908.

关键词： behaviour subsequent sizes

High-Intensity Interval Training Prescribed Within the Secondary Severe-Intensity Domain Improves Critical Speed But Not Finite Distance Capacity

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Journal of Science in Sport and Exercise 2020年第2期2卷 154-166页

作者： emma JThomas Robert W.Pettitt mark Kramer Biokinetics and Sport Science Unit Nelson Mandela UniversityPort Elizabeth 6070South Africa Rocky mountain University of Health Professions ProvoUT 84606USA Physical Activity Sport and Recreation Research Focus AreaNorth West UniversityPotchefstroom 2520South Africa

Purpose Improvements in D'(the fatigability constant for running)subsequent to training interventions remain ***-intensity interval training(HIIT)within the severe intensity domain for short durations(min)have been theorized to improve D'.The purpose of the present study was to assess this in a group of moderately trained *** Eighteen participants completed graded exercise testing(GXT),40-m sprint testing and a 3-min all-out test(3mT)for running to determine key mechanistic and physiological *** were randomly assigned into one of two groups based on intensity prescription(G140%=140%of critical speed[CS]),or time intervals(G90-s=90-s)to complete a twice-weekly training intervention for 6-weeks followed by *** No between-group differences were present either prior to or following the *** and meaning-ful improvements were detected during the post-intervention period for both groups for VO2max(G140%:+7.60%;G90-s:+11.67%),speed evoking VO2max(sVO2max;G140%:+4.33%;G90_s:+2.92%),gas exchange threshold(GET;G140%:+12.02%;G90-s:+20.52%),speed evoking GET(sGET;G140%:+4.17%;G90_s:+7.92%),CS(G140%:m=0.62 m/s;G90-s:m=0.46 m/s),D'(G140%:m=-56.34 m;G90-s:m=-18.36 m),FI%(G140%m=-6.75%;G90-s:m=-4.38%)and maximal distance(G140%:m=49.67 m;G90_s:m=58.38 m).Conclusions The prescribed intensities and durations were insufficient to elicit improvements in D'.Improvements in D'may be dependent on very short-duration intervals(i.e.maximal sprint speed.

关键词： moderately active Severe intensity Threshold

Development of a modular, biocompatible thiolated gelatin microparticle platform for drug delivery and tissue engineering applications

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Regenerative Biomaterials 2021年第3期8卷 45-56页

作者： Hannah A.Pearce Yu Seon Kim emma Watson Kiana Bahrami mollie m.Smoak Emily Y.Jiang michael Elder Tate Shannon Antonios G.mikos Department of Bioengineering Rice University6500 Main StreetHoustonTX 77030USA

The field of biomaterials has advanced significantly in the past *** the growing need for high-throughput manufacturing and screening,the need for modular materials that enable streamlined fabrication and analysis of tissue engineering and drug delivery schema has *** are a powerful platform that have demonstrated promise in enabling these technologies without the need to modify a bulk *** building block paradigm of using microparticles within larger scaffolds to control cell ratios,growth factors and drug release holds *** microparticles(GmPs)are a well-established platform for cell,drug and growth factor *** of the challenges in using GmPs though is the limited ability to modify the gelatin *** the present work,we hypothesized that by thiolating gelatin before microparticle formation,a versatile platform would be created that preserves the cytocompatibility of gelatin,while enabling post-fabrication *** thiols were not found to significantly impact the physicochemical properties of the ***,the thiolated GmPs were demonstrated to be a biocompatible and robust platform for mesenchymal stem cell ***,the thiolated particles were able to be covalently modified with a maleimide-bearing fluorescent dye and a peptide,demonstrating their promise as a modular platform for tissue engineering and drug delivery applications.

关键词： gelatin microparticles thiolated gelatin microparticles click chemistry cell delivery drug delivery tissue engineering biomaterials

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改变行为:着眼2050年净零排放目标

英国医学杂志中文版 2022年第1期25卷 12-15页

作者： Theresa m marteau Nick Chater emma E Garnett 夏爽(翻译) University of Cambridge Warwick Business School University of Warwick 中华外科杂志编辑部

Theresa marteau和团队主张,应迅速、彻底地改善支撑不健康且不可持续行为的基础设施和价格体系。包括美国、欧盟和英国在内的多数主要经济体承诺,在2050年前实现温室气体净零排放,以遏制气候变化。要达到这一目标,并最大程度减少累积... 详细信息

Theresa marteau和团队主张,应迅速、彻底地改善支撑不健康且不可持续行为的基础设施和价格体系。包括美国、欧盟和英国在内的多数主要经济体承诺,在2050年前实现温室气体净零排放,以遏制气候变化。要达到这一目标,并最大程度减少累积碳排放量,我们需要立即采取行动。然而,目前的行动还跟不上承诺、以英国为例,尽管它率先以立法的形式确定了2050年前实现净零排放的目标。

关键词：基础设施零排放价格体系气候变化温室气体持续行为主要经济体承诺

A database of experimentally measured lithium solid electrolyte conductivities evaluated with machine learning

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npj Computational materials 2023年第1期9卷 2265-2278页

作者： Cameron J.Hargreaves michael W.Gaultois Luke m.Daniels emma J.Watts Vitaliy A.Kurlin michael moran Yun Dang Rhun morris Alexandra morscher Kate Thompson matthew A.Wright Beluvalli-Eshwarappa Prasad Frédéric Blanc Chris m.Collins Catriona A.Crawford Benjamin B.Duff Jae Evans Jacinthe Gamon Guopeng Han Bernhard T.Leube Hongjun Niu Arnaud J.Perez Aris Robinson Oliver Rogan Paul m.Sharp Elvis Shoko manel Sonni William J.Thomas Andrij Vasylenko Lu Wang matthew J.Rosseinsky matthew S.Dyer Department of Chemistry University of LiverpoolLiverpool L697ZDUK Leverhulme Research Centre for Functional materials Design Materials Innovation FactoryUniversity of LiverpoolLiverpool L73NYUK Department of Computer Science University of LiverpoolLiverpool L693BXUK Stephenson Institute for Renewable Energy University of LiverpoolLiverpool L697ZFUK

The application of machine learning models to predict material properties is determined by the availability of high-quality *** present an expert-curated dataset of lithium ion conductors and associated lithium ion conductivities measured by *** *** dataset has 820 entries collected from 214 sources;entries contain a chemical composition,an expert-assigned structural label,and ionic conductivity at a specific temperature(from 5 to 873°C).There are 403 unique chemical compositions with an associated ionic conductivity near room temperature(15–35°C).The materials contained in this dataset are placed in the context of compounds reported in the Inorganic Crystal Structure Database with unsupervised machine learning and the Element movers *** dataset is used to train a CrabNet-based classifier to estimate whether a chemical composition has high or low ionic *** classifier is a practical tool to aid experimentalists in prioritizing candidates for further investigation as lithium ion conductors.

关键词： spectroscopy lithium classifier