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Accident and hazard prediction models for highway–rail grade crossings:a state-of-the-practice review for the USA

Railway Engineering Science 2020年第3期28卷 251-274页

作者： Olumide f.Abioye Maxim A.Dulebenets Junayed Pasha Masoud Kavoosi Ren Moses john Sobanjo Eren E.Ozguven Department of Civil and Environmental Engineering Florida A&M University-Florida State University2525 Pottsdamer StreetTallahasseeFL 32310-6046USA

Highway–rail grade crossings(HRGCs)are one of the most dangerous segments of the transportation *** year numerous accidents are recorded at HRGCs between highway users and trains,between highway users and traffic control devices,and solely between highway *** accidents cause fatalities,severe injuries,property damage,and release of hazardous *** and state Departments of Transportation(DOTs)have addressed safety concerns at HRGCs in the USA by investigating the factors that may cause accidents at HRGCs and developed certain accident and hazard prediction models to forecast the occurrence of accidents and crossing *** accident and hazard prediction models are used to identify the most hazardous HRGCs that require safety *** study provides an extensive review of the state-of-the-practice to identify the existing accident and hazard prediction formulae that have been used over the years by different state ***,this study analyzes the common factors that have been considered in the existing accident and hazard prediction *** reported performance and implementation challenges of the identified accident and hazard prediction formulae are discussed in this study as *** on the review results,the US DOT Accident Prediction formula was found to be the most commonly used formula due to its accuracy in predicting the number of accidents at ***,certain states still prefer customized models due to some practical *** availability and data accuracy were identified as some of the key model implementation challenges in many states across the country.

关键词： Highway–rail grade crossings Accident prediction methods Hazard prediction methods Resource allocation Critical review

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The heterodimeric structure of heterogeneous nuclear ribonucleoprotein C1/C2 dictates 1,25-dihydroxyvitamin D-directed transcriptional events in osteoblasts

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Bone Research 2014年第2期2卷 110-120页

作者： Thomas S Lisse Kanagasabai Vadivel S Paul Bajaj Rui Zhou Rene f Chun Martin Hewison john S Adams Department of Orthopaedic Surgery and the Orthopaedic Hospital Research Center UCLA Los Angeles CA USA Department of Regenerative Biology and Medicine Mount Desert Island Biological Laboratory Bar Harbor ME USA

Heterogeneous nuclear ribonucleoprotein （hnRNP） C plays a key role in RNA processing but also exerts a dominant negative effect on responses to 1,25-dihydroxyvitamin D （1,25（OH）2D） by functioning as a vitamin D response element-binding protein （VDRE-BP）. hnRNPC acts a tetramer of hnRNPC1 （huC1） and hnRNPC2 （huC2）, and organization of these subunits is critical to in vivo nucleic acid-binding. Overexpression of either huC1 or huC2 in human osteoblasts is sufficient to confer VDRE-BP suppression of 1,25（OH）2D-mediated transcription. However, huC1 or huC2 alone did not suppress 1,25（OH）2D-induced transcription in mouse osteoblastic cells. By contrast, overexpression of huC1 and huC2 in combination or transfection with a bone-specific polycistronic vector using a ＂self-cleaving＂ 2A peptide to co-express huC1/C2 suppressed 1,25D-mediated induction of osteoblast target gene expression. Structural diversity of hnRNPC between human/NWPs and mouse/rat/rabbit/dog was investigated by analysis of sequence variations within the hnRNP CLZ domain. The predicted loss of distal helical function in hnRNPC from lower species provides an explanation for the altered interaction between huC1/C2 and their mouse counterparts. These data provide new evidence of a role for hnRNPC1/C2 in 1,25（OH）2D-driven gene expression, and further suggest that species-specific tetramerization is a crucial determinant of its actions as a regulator of VDR-directed transactivation.

关键词： gene The heterodimeric structure of heterogeneous nuclear ribonucleoprotein C1/C2 dictates 1,25-dihydroxyvitamin D-directed transcriptional events in osteoblasts figure EcoRI

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A Biomimetic Approach to Robot Locomotion in Unstructured and Slippery Environments

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Journal of Bionic Engineering 2005年第1期2卷 1-14页

作者： Giovanni La Spina Thomas Hesselberg john Williams Julian f V Vincent Scuola Superiore Sant'Anna Centre for Biomimetic and Natural TechnologiesCentre for Biomimetic and Natural TechnologiesCentre for Biomimetic and Natural Technologies Polo Sant'Anna ValderaCRIM LabViale Rinaldo Piaggio3456025-Pontedera (Pisa)ItalyDepartment of Mechanical Engineering University of BathBathBA2 7AYUKDepartment of Mechanical Engineering University of BathBathBA2 7AYUKDepartment of Mechanical Engineering University of BathBathBA2 7AYUK

While much attention has been given to bio-robotics in recent years, not much of this has been given to the challenging subject of locomotion in slippery conditions. This study begins to rectify this by proposing a biomimetic approach to generating the friction required to give sufficient propulsive force on a slippery substrate. We took inspiration from a successful biological solution-that of applying hair-like structures to the propulsive appendages, similar to the setae found in nereid polychaetes living in muddy habitats. We began by examining the morphology and the mean locomotion parameters of one of the most common nereids.. Nereis diversicolor. following this study, we designed and fabricated a robotic system with appendages imitating the biological shape found in the worm. A flexible control system was developed to allow most of the locomotion parameters observed in the real worm to be applied to the robot. Experiments on three different natural substrates ranging from fine sand to gravel showed that, whereas a plate attached to the appendage generated most thrust on a small particle substrate, a bundle of artificial setae attached to the appendage generated most thrust on a large particle substrate. On all types of substrate tested, an appendage without any attachment did significantly worse than one with. This suggests that hair-like structures can be advantageous.

关键词： bio-robotics biomimetics polychaeta thrust generation friction

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Assessing methods for multiple imputation of systematic missing data in marine fisheries time series with a new validation algorithm

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Aquaculture and fisheries 2023年第5期8卷 587-599页

作者： Ivan f.Benavides Marlon Santacruz Jhoana P.Romero-Leiton Carlos Barreto john Josephraj Selvaraj Instituto de Estudios del Pacífico Universidad Nacional de ColombiaTumaco CampusKilometro 30-31CajapíVía Nacional Tumaco-PastoTumacoNarino522020Colombia Ingeniería en Produccion Acuícola Universidad de NarinoCra.22#30-63Torre 4 apto.703San Juan de PastoNarino520004Colombia facultad de ingeniería Universidad CesmagPasto520004Colombia Datambiente 520001Colombia Autoridad Nacional de Pesca y Acuicultura(AUNAP) 520001Colombia

Time series from fisheries often contain multiple missing *** is a severe limitation that prevents using the data for research on population dynamics,stock assessment,forecasting,and,hence,decision-making around marine *** methods have been proposed to impute missing data in univariate time ***,their performances depend not only on the amount of missing data but also on the data *** study compares the performance of twelve imputation methods on the time series of marine fishery landings for six species in the Colombian Pacific *** other studies,we validate the precision of the imputations in the same target time series that include missing data,using the Known Sub-Sequence Algorithm(KSSA),a novelty validation approach that simulates missing data in known sub-sequences of the target time *** results showed that the best methods for imputation are Seasonal Decomposition with Kalman filters and Structural Models with Kalman filters fitted by maximum *** also show that validating the imputation methods with other time series different to the target time series,leads to wrong imputation methods *** is noteworthy that these methods and also the validation framework are mainly suited to time series with non-random distribution of missing data,this is,missing data produced systematically in chunks or clusters with predictable frequency,which are common in marine sciences.

关键词： Data gaps fish populations Artisanal fishing Time series imputation

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The influence of abiotic and spatial variables on woody and herbaceous species abundances in a woodland-grassland system in the Eastern Terai of India

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Journal of Plant Ecology 2022年第1期15卷 155-167页

作者： Dhritiman Das Subham Banerjee john Lehmkuhl Jagdish Krishnaswamy Robert john Academy of Conservation Science and Sustainability Studies Ashoka Trust for Research in Ecology and the Environment(ATREE)Royal EnclaveSriramapuraJakkur PostBangalore 560064India Manipal Academy of Higher Education Manipal 576104KarnatakaIndia Pygmy Hog Conservation Programme Durrell Wildlife Conservation TrustLes Augres ManorLa Profonde RueTrinityJersey JE35BPChannel Islands Department of Biological Sciences Indian Institute of Science Education and ResearchKolkataRoom 214Research ComplexMohanpur 741246West BengalIndia USDA forest Service Pacific Northwest Research StationWenatcheeWA 98801USA

The environmental factors that influence tree-grass abundances in tropical savanna and grasslands are not well understood,particularly for woodland-grassland mosaics in humid *** studied the effects of abiotic and spatial variables on woody and herbaceous species distributions in a Terai ecosystem of northeastern *** evaluated the importance of climatic and non-climatic factors that maintain variable tree-grass ratios across the landscape,and also accounted for spatial connectivity and *** measured species abundances of woody and herbaceous plant species in 134 plots with each 30 m×30 m in a 519 km^(2)protected Terai habitat,and derived several climatic and non-climatic environmental *** constructed variables based on different models of spatial connectivity among sites,to test their influence on species *** then used redundancy analyses and variation partitioning to quantify the importance of environmental variables and spatial structure on variation in tree-grass *** found that environmental variables including rainfall,fire,water stress,topography and soil nutrients had statistically significant effects on species abundance and tree-grass *** structure was significant,and the best spatial model was an inverse distance-weighted model with linkage extending to 23.5 km,indicating weak dispersal *** 21%of the variation in species abundance was explained by the selected environmental and spatial *** results indicate that dynamic plant communities in which spatial-temporal variation in environmental factors may drive stochasticity in species distribution and abundance,thus dominantly influencing on the vegetation mosaic.

关键词： woodland-grassland Eastern Terai Manas National Park variation partitioning ground fires spatial connectivity

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Iwasawa Theory of Quadratic Twists of X0（49）

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Acta Mathematica Sinica,English Series 2018年第1期34卷 19-28页

作者： Junhwa CHOI john COATES Department of Mathematics POSTECH Emmanuel College Cambridge University

The field K ---- Q（x/-AT） is the only imaginary quadratic field with class number 1, in which the prime 2 splits, and we fix one of the primes p of K lying above 2. The modular elliptic curve X0 （49） has complex multiplication by the maximal order O of K, and we let E be the twist of Xo （49） by the quadratic extension K（v/M）/K, where M is any square free element of O with M -- i mod 4 and （M, 7） = 1. In the present note, we use surprisingly simple algebraic arguments to prove a sharp estimate for the rank of the MordeII-Weil group modulo torsion of E over the field f∞=k（Ep∞ ）, where Epic denotes the group of p∞-division points on E. Moreover, writing B for the twist of X0（49） by K（C/ET）/K, our Iwasawa-theoretic arguments also show that the weak form of the conjecture of Birch and Swinnerton-Dyer implies the non-vanishing at s =1 of the complex L-series of B over every finite layer of the unique Z2-extension of K unramified outside p. We hope to give a proof of this last non-vanishing assertion in a subsequent paper.

关键词： Birch-Swinnerton-Dyer conjecture elliptic curves Iwasawa theory

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Computational fluid dynamics simulation on the longwall gob breathing

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International Journal of Mining Science and Technology 2017年第2期27卷 185-189页

作者： Samuel A.Lolon Jürgen f.Brune Gregory E.Bogin Jr. john W.Grubb Saqib A.Saki Aditya Juganda Department of Mining Engineering Colorado School of MinesCO 80401USA Department of Mechanical Engineering Colorado School of Mines CO 80401USA

In longwall mines, atmospheric pressure fluctuations can disturb the pressure balance between the gob and the ventilated working area, resulting in a phenomenon known as ‘‘gob breathing". Gob breathing triggers gas flows across the gob and the working areas and may result in a condition where an oxygen deficient mixture or a methane accumulation in the gob flows into the face area. Computational fluid Dynamics(CfDs) modeling was carried out to analyze this phenomenon and its impact on the development of an explosive mixture in a bleeder-ventilated panel scheme. Simulation results indicate that the outgassing and ingassing across the gob and the formation of Explosive Gas Zones(EGZs) are directly affected by atmospheric pressure changes. In the location where methane zones interface with mine air, EGZ fringes may form along the face and in the bleeder entries. These findings help assess the methane ignition and explosion risks associated with fluctuating atmospheric pressures.

关键词： CfDs Gob breathing barometric pressure Explosive gas zone Longwall mine Methane explosion

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Re-evaluating monazite as a record of metamorphic reactions

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Geoscience frontiers 2022年第2期13卷 237-254页

作者： Kyle P.Larson Sudip Shrestha john M.Cottle Carl Guilmette T.Alex johnson H.Daniel Gibson félix Gervais Department of Earth Environmental and Geographic SciencesUniversity of British Columbia Okanagan3247 University WayKelownaBC V1V 1V7Canada fipke Laboratory for Trace Element Research University of British Columbia Okanagan3247 University WayKelownaBC V1V 1V7Canada Department of Earth Science University of CaliforniaSanta BarbaraSanta BarbaraCA 93106-9630USA Géologie et Génie Géologique UniversitéLavalQuébec CityQuebecCanada Department of Earth Sciences Simon Fraser University8888 University DriveBurnabyBC V5A 1S6Canada Départment des Génies Civil Géologique et des MinesPolytechnique MontréalMontréalQC H3T 1J4Canada

This study presents a re-examination of historical specimens(DG136 and DG167)from the Monashee complex in the southeastern Canadian Cordillera that are critical to the current understanding of rare earth element(REE)distribution between garnet and monazite(and other accessory minerals)during ***-hundred and fifty-one new monazite petrochronology spot analyses on 29 different grains across two specimens outline detailed(re)crystallization *** element data collected from the same ablated volume,interpreted in the context of new phase equilibria modelling that includes monazite,xenotime and apatite,link ages to specific portions of the pressure-temperature(P-T)paths followed by the *** linkages are further informed by garnet Lu-Hf geochronology and xenotime *** clockwise P-T paths indicate prograde metamorphism was ongoing by ca.80 Ma in both *** structurally deeper specimen,DG136,records peak P-T conditions of~755-770℃and 8.8-10.4 kbar,interpreted to coincide with(re-)crystallization of low Y monazite at~75-70 ***-rim garnet isopleths from DG167 cross in the observed peak assemblage field at~680℃ and 9.3 *** conditions are interpreted to correspond with low Y monazite(re-)crystallisation at~65 *** specimens record decompression along their retrograde path coincident with high Y 70-55 Ma and 65-55 Ma monazite populations in DG136 and DG167,*** findings broadly agree with those initially reported~20 years ago and confirm early interpretations using trace elements in monazite as generally reliable markers of metamorphic *** phase equilibria modelling and in situ petrochronological analysis,however,provide additional insight into monazite behaviour during anatexis and the effects of potential trace element buffering by REE-bearing phases such as apatite.

关键词： Monazite petrochronology Phase equilibria modelling Geochronology P-T-t paths

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Multi-scale magnetic resonance measurements and validation of Discrete Element Model simulations

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Particuology 2011年第4期9卷 330-341页

作者： Christoph R. Müller Daniel J. Holland James R. Third Andrew J. Sederman john S. Dennis Lynn f. Gladden Institute of Energy Technology Department of Mechanical and Process Engineering Department of Chemical Engineering and Biotechnology University of Cambridge

This short review describes the capabilities of magnetic resonance （MR） to image opaque single- and two-phase granular systems, such as rotating cylinders and gas-fluidized beds operated in different fluidization regimes. The unique capability of MR to not only image the solids＇ distribution （voidage） but also the velocity of the particulate phase is clearly shown. It is demonstrated that MR can provide measurements over different length and time scales. With the MR equipment used for the studies summarized here, temporal and spatial scales range from sub-millisecond to hours and from a few hundred micrometres to a few centimetres, respectively. Besides providing crucial data required for an improved understanding of the underlying physics of granular flows, multi-scale MR measurements were also used to validate numerical simulations of granular systems. It is shown that predictions of time-averaged properties, such as voidage and velocity of the particulate phase, made using the Discrete Element Model agree very well with MR measurements.

关键词： Discrete Element Modelling Magnetic resonance imaging MultiscaleGas-fluidized beds Rotating cylinders

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Do male and female beetles (Tenebrio molitor) respond differently to rat feces containing eggs from the tapeworm, Hymenolepis diminuta?

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Natural Science 2010年第8期2卷 855-859页

作者： john f. Shea 不详

Males and females often differ in their susceptibility and exposure to infection. Thus, they may also differ in their ability to avoid infection. The beetle, Tenebrio molitor, risks infection with cysticercoids when ingesting rat feces containing eggs of the tapeworm, Hymenolepis diminuta. Previous studies demonstrated that beetles sometimes prefer infective feces suggesting that the tapeworm influences the foraging behavior of beetles. After recording beetle movement in an arena containing infective and uninfective feces for one hour, sex main effects were not significant, but the effect of sex asked in trials was significant for males. Specifically, more male beetles occurred on the uninfective bait than on the infective bait. This observation suggests that male beetles avoid infective feces, which decreases their probability of infection with H. diminuta. If the cost of infection is higher in males, then selection to avoid infective feces may act more strongly on males.

关键词： Hymenolepis diminuta Cysticercoid Tenebrio molitor Behavior Coprophagy Parasite Manipulation

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