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Plant growth in a fragmented forest is a consequence of top-down and bottom-up processes, but not their interaction

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Journal of Plant Ecology 2017年第4期10卷 601-609页

作者： Brad J.Farmilo john W.morgan Dale g.Nimmo Department of Ecology Environment and EvolutionLa Trobe University1 Kingsbury DriveBundooraVictoria 3086Australia Department of Environment LandWater and PlanningArthur Rylah Institute for Environmental Research123 Brown StreetHeidelbergVictoria 3084Australia Centre for Integrative Ecology School of Life and Environmental SciencesDeakin University221 Burwood HighwayBurwoodVictoria 3125Australia Institute for Land Water and SocietySchool of Environmental ScienceCharles Sturt University1 Elizabeth Mitchell DriveAlburyNew South Wales 2640Australia

Aims Habitat loss and fragmentation are the leading causes of global biodiversity *** fragmentation(leading to edge effects,increased isolation and declining habitat size)interacts with top-down processes like vertebrate herbivory,an important driver of vegetation structure and composition in many ecosystems,is poorly *** between fragmentation and changes in her-bivory may exacerbate their individual influences on plant growth,with implications for management of native plant communities within fragmented *** examined the effects of habitat fragmentation on herbivore activity,and also how both fragmen-tation and mammalian herbivory influence growth of understorey plant *** This study was conducted at the Wog Wog habitat fragmentation experiment,located in south-eastern New South Wales,*** use herbivore exclusion plots across an experimentally frag-mented landscape to assess the interactive effects of fragmenta-tion and herbivory on the growth of four plant species that vary in growth form and rarity in the *** Findings We observed species-specific responses to both herbivory and fragmentation,but no additive or interactive effects between these *** show that a reduction in herbivore activity within frag-ments does not correspond with an increase in plant growth,even for the most palatable ***,top-down processes continue to operate across the fragmented *** changes in habitat conditions within fragments appear to negatively influence both plant growth and mammalian herbivore activity,it is likely that alterations to bottom-up effects(***)may be more important than top-down effects(***)for the spe-cies under *** species-specific response of plants to herbivory or fragmentation may have implications for temporal and spatial population persistence in fragmented landscapes and ulti-mately fragment vegetation structure.

关键词： Wog Wog habitat fragmentation experiment Pinus radiata herbivory understorey plants plantation eucalypt

Spontaneous passage of common bile duct stones in jaundiced patients

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Hepatobiliary & Pancreatic Diseases International 2011年第2期10卷 209-213页

作者： Valentina Lefemine Richard john morgan Department of general Surgery Glan Clwyd Hospital

BACKgROUND:Common bile duct(CBD)stones are known to pass spontaneously in a significant number of patients. This study investigated the rate of spontaneous CBD stones passage in a series of patients presenting with jaundice due to *** patients were managed surgically,allowing CBD intervention to be avoided in the event of spontaneous passage of CBD stones. METHOD:Retrospective analysis of patients presenting with jaundice due to CBD stones,and managed surgically with laparoscopic cholecystectomy and intra-operative cholangiogram with or without CBD exploration. RESULTS:The jaundice settled pre-operatively in 76/108 patients, and in 60/108 the CBD stones had passed spontaneously by the time of *** 60 patients avoided any intervention to their CBD. CONCLUSIONS:CBD stones pass spontaneously in more than half of jaundiced *** management(laparoscopic cholecystectomy and intra-operative cholangiogram,with willingness to perform CBD exploration if positive)allows the avoidance of CBD intervention in these patients.

关键词： cholecystectomy cholangiogram common bile duct stones

Coal rib response during bench mining: A case study

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International Journal of Mining Science and Technology 2018年第1期28卷 107-113页

作者： morgan M.Sears john Rusnak Mark Van Dyke gamal Rashed Khaled Mohamed Michael Sloan ground Control Branch NIOSH Pittsburgh Mining Research Division

In 2016, room-and-pillar mining provided nearly 40% of underground coal production in the United *** the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in *** coal *** of these 12 fatalities(75%) have occurred in room-andpillar *** objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 *** paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated numerical model of the observed rib response, and application of this calibrated model to a second site.

关键词： Deep cover Bench mining Thick seam Retreat mining Rib response Rib support

LIQUID CRYSTAL BASED ROTATINg ORTHOgONAL POLARIZATION IMAgINg SYSTEM

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Journal of Innovative Optical Health Sciences 2009年第3期2卷 245-251页

作者： QUN ZHU IAN M.STOCKFORD john A.CROWE STEPHEN P.morgan School of Electrical and Electronic Engineering University of Nottingham University Park NottinghamUK NG72RD

Rotating orthogonal polarization imaging provides images of the polarization properties of scattering media which are free from surface *** the technique has been demonstrated using manually rotated glan–Thompson polarizers to control and analyze the polarization state of the light entering and emerging from the *** paper describes a system that performs these functions using liquid crystal *** system is tested using a polarizing target embedded within a scattering medium and is compared with Monte Carlo *** results compare well with those obtained with manual rotation of *** liquid crystal based approach has advantages over the previous system in terms of ease of use,speed,and repeatability and is therefore an important step towards taking the technique into routine clinical use.

关键词： Liquid crystal polarization orthogonal surface reflection scattering tissue.

Seasonal exports of phosphorus from intensively fertilised nested grassland catchments

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Journal of Environmental Sciences 2013年第9期25卷 1847-1857页

作者： Ciaran Lewis Rashad Rafique Nelius Foley Paul Leahy gerard morgan john Albertson Sandeep Kumar gerard Kiely Department of Civil and Environmental Engineering University College Cork Department of Microbiology and Plant Biology University of Oklahoma Environmental Research Institute University College Cork Aquatic Services Unit Environmental Research Institute University College Cork Department of Civil and Environmental Engineering Duke University Department of Plant Science South Dakota State University

We carried out a one year （2002） study of phosphorus （P） loss from soil to water in three nested grassland catchments with known P input in chemical fertilizer and animal liquid slurry applications. Chemical fertilizer was applied to the grasslands between March and September and animal slurry was applied over the twelve months. The annual chemical P fertilizer applications for the 17 and 211 ha catchments were 16.4 and 23.7 kg P/ha respectively and the annual slurry applications were 10.7 and 14.0 kg P/ha, respectively. The annual total phosphorus （TP） export in stream-flow was 2.61, 2.48 and 1.61 kg P/ha for the 17, 211 and 1524 ha catchments, respectively, compared with a maximum permissible （by regulation） annual export of ca. 0.35 kg P/ha. The export rate （ratio of P export to P in land applications） was 9.6% and 6.6% from the 17 and 211 ha catchments, respectively. On average, 70% of stream flow and 85% of the P export occurred during the five wet months （October to February） indicating that when precipitation is much greater than evaporation, the hydrological conditions are most favourable for P export. However the soil quality and land use history may vary the results. Particulate P made up 22%, 43% and 37% of the TP export at the 17, 211 and 1524 ha catchment areas, respectively. As the chemical fertilizer was spread during the grass growth months （March to September）, it has less immediate impact on stream water quality than the slurry applications. We also show that as the catchment scale increases, the P concentrations and P export decrease, confirming dilution due to increasing rural catchment size. In the longer term, the excess P from fertilizer maintains high soil P levels, an antecedent condition favourable to P loss from soil to water. This study confirms the significant negative water quality impact of excess P applications, particularly liquid animal slurry applications in wet winter months. The findings suggest that restricted P application in w

关键词： phosphorus fertilizer slurry exports grassland land management water quality eutrophication

Upper range limit establishment after wildfire of an obligateseeding montane forest tree fails to keep pace with 20th century warming

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Journal of Plant Ecology 2018年第2期11卷 200-207页

作者： john W.morgan James D.Vincent James S.Camac Research Centre for Applied Alpine Ecology Department of EcologyEnvironment and EvolutionLa Trobe UniversityKingsbury DriveBundooraVIC 3086Australia Department of Biological Sciences Macquarie UniversityBalaclava RoadNorth RydeNew South Wales 2109Australia

Aims How species respond to climate change at local scales will depend on how edaphic and biological characteristics interact with species physiological limits and traits such as *** seeders,those species that depend on fire for recruitment,have few and epi-sodic opportunities to track a changing climate *** such cases,long-distance seed dispersal will be necessary to take advan-tage of rare recruitment *** examine recruitment patterns and seedling growth below,at and above the timberline of an obligate-seeding Australian montane forest tree(Eucalyptus delegatensis)after stand-replacing fire,and place these changes in the context of regional *** We use two methods to detect whether *** can estab-lish and persist above the timberline after stand-replacing wildfire in montane forests in south-east ***,we examine estab-lishment patterns by using belt transects at six sites to quantify how changes in post-fire recruit density with increasing distance above the timberline seven years ***,to determine whether dispersal or physiological constraints determine post-fire establish-ment patterns,we transplanted seedlings and saplings into bare ground above(100 m elevation),at,and below(50 m elevation)timberline 18-months after *** monitored seedling growth and survival for one growing *** Findings There was minimal upslope migration of the species after fire with most saplings observed near seed-bearing timberline trees,with only occasional outpost *** seedlings and saplings sur-vived equally well across one growing season when planted above existing timberlines,relative to saplings at or below the *** and sapling growth rates also did not differ across these location,although seedlings grew at much faster rates than *** findings suggest that upslope growing season conditions are unlikely to limit initial range expansion of trees aft

关键词： climate change dispersal limitation growth rates regeneration niche timberline

Two-way communication: Volatile emission and uptake occur through the same barriers

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Molecular Plant 2023年第1期16卷 1-3页

作者： Joshua R.Widhalm Meng-Ling Shih john A.morgan Natalia Dudareva Department of Horticulture and Landscape Architecture Purdue UniversityWest LafayetteIN 47907USA Center for Plant Biology Purdue UniversityWest LafayetteIN 47907USA avidson School of Chemical Engineering Purdue UniversityWest LafayetteIN 47907USA Department of Biochemistry Purdue UniversityWest LafayetteIN 47907USA

Volatile organic compounds(VOCs)are released from aboveground organs into the atmosphere and/or from roots into the soil,allowing plants to communicate and interact with their environment,including with each ***-plant communication via VOCs includes intra-and inter-species signaling as well as within-plant *** some recipient tissues,for example,VOC perception encompasses storing the modified VOC for direct defense against herbivores(Sugimoto et al.,2014)or increasing tolerance to abiotic stresses(Zhao et al.,2020).In addition,or alternatively,perceived VOCs may initiate signaling cascades that prime plant defenses(Brosset and Blande,2022).In all cases,plant VOCs are first released into the environment before being taken up and perceived by the same or neighboring *** significant progress has been made over the last several years to elucidate how VOCs are released from plant cells,these studies have also revealed new questions about how communicated VOCs are imported across cellular *** reviews(Loreto and D’Auria,2022;Wang and Erb,2022)and a special issue(Vlot and Rosenkranz,2022)have proposed mechanisms for VOC perception and *** this Opinion piece,we shed light on the gaps in knowledge about VOC import and offer perspectives for future research aiming at understanding the molecular mechanisms underlying VOC-mediated communication in plants.

关键词： communicate soil barriers

When Students Become“Prisoners”:A game Theory Analysis of Internship by Beijing College Students

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ECNU Review of Education 2018年第2期1卷 44-73页

作者： Xiaohao Ding Wei Ha Le Kang W.john morgan graduate School of Education Peking University Cardiff University

Purpose-The oversupply of college graduates and increasing competition in the Chinese urban labor market have forced college students to undertake internships much earlier and to a greater intensity in the hope of boosting their employment *** may be argued that the considerable time and energy thus spent on internships is deleterious to their university *** paper considers the factors that determine the intensity of an internship ***/Approach/Methods-Building on a Cobb-Douglas utility function,the paper constructs a Prisoners’Dilemma game to model the internship behavior of Chinese college students,and then examines the determinants of internship using data from a 2011 survey of approximately 10,000 Chinese college students from 47 higher education institutions in the Beijing metropolitan area and multivariate regression ***-Empirical results confirm three key hypotheses derived from our model:first,students’perceptions of higher differentials across available jobs in the labor market entice them to intern excessively;second,the improving quality of college teaching and the consequent benefit for knowledge acquisition mitigates the need for excessive internship;third,student preferences for fundamental knowledge acquisition also tilts the balance towards more study and less ***/Value-These findings suggest that in the context of a tight graduate labor market,improving the quality of college teaching provides a viable alternative to excessive internship by students.

关键词： Prisoners’dilemma game theory Cobb-Douglas utility function college student internship

China Scholars issue Personal Invitation to British Youth

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海外华文教育动态 2011年第12期 135-136页

作者： By john morgan