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Origins of the supercontinent cycle

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Geoscience Frontiers 2013年第4期4卷 439-448页

作者： R.Damian Nance j.brendan murphy Department of Geological Sciences.316 Clippinger Laboratories.Ohio University.Athens.OH 45701.USA Department of Earth Sciences st.Francis Xavier UniversityAntigonishNova Scotia B2G 2W5.Canada

The supercontinent cycle, by which Earth history is seen as having been punctuated by the episodic assembly and breakup of supercontinents, has influenced the rock record more than any other geologic phenomena, and its recognition is arguably the most important advance in Earth Science since plate tectonics. It documents fundamental aspects of the planet＇s interior dynamics and has charted the course of Earth＇s tectonic, climatic and biogeochemical evolution for billions of years. But while the widespread realization of the importance of supercontinents in Earth history is a relatively recent development, the supercontinent cycle was first proposed thirty years ago and episodicity in tectonic processes was recognized long before plate tectonics provided a potential explanation for its occurrence. With interest in the supercontinent cycle gaining momentum and the literature expanding rapidly, it is instructive to recall the historical context from which the concept developed. Here we examine the supercontinent cycle from this perspective by tracing its development from the early recognition of long-term epi- sodicity in tectonic processes, through the identification of tectonic cycles following the advent of plate tectonics, to the first realization that these phenomena were the manifestation of episodic superconti- nent assembly and breakup.

关键词： Supercontinent cyclePlate tectonicsTectonic episodicitySecular trends

Trial by fire:Testing the paleolongitude of Pangea of competing reference frames with the African LLSVP

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Geoscience Frontiers 2020年第4期11卷 1253-1256页

作者： Ross N.Mitchell Lei Wu j.brendan murphy Zheng-Xiang Li State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina Earth Dynamics Research Group The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin UniversityGPO Box U1987PerthWAAustralia Department of Earth Sciences St.Francis Xavier UniversityAntigonishNova ScotiaCanada

Paleogeography can be reconstructed using various crust-or mantle-based reference frames that make fundamentally different *** various reconstruction models differ significantly in continental paleolongitude,but it has been difficult to assess which models are more *** suggest here a "LLSVP test",where an assumed correlation between present-day large low velocity shear-wave provinces and the paleogeography of supercontinent Pangea at breakup ca.200 million years ago can be used to assess the relative accuracy of published *** correlations between continental paleolongitude and the African LLSVP are achieved with mantle-based reference frames(moving hotspots and true polar wander),whereas shallower crustbased reference frames are shown to be *** relative success of mantle-based frames,and thus the importance of the depth of reference frame,supports the notion that mantle convection is largely vertical compared to the horizontal plate motion of tectonics.

关键词： Palaeogeography Plate tectonics LLSVPs Reference frames

A brief history of the Rheic Ocean

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Geoscience Frontiers 2012年第2期3卷 125-135页

作者： R.Damian Nance Gabriel Gutirrez-Alonso j.Duncan Keppie Ulf Linnemann j.brendan murphy Cecilio Quesada Rob A.Strachan Nigel H.Woodcock Department of Geological Sciences 316 Clippinger Laboratories Ohio University Departamento de Geología Universidad de Salamanca 33708 Salamanca Departamento de Geología Regional Instituto de Geología Universidad Nacional Autónoma de Mxico Senckenberg Naturhistorische Sammlungen Dresden Museum fur Mineralogie und Geologie Konigsbrucker Landstra βe 159D-01109 DresdenGermany Department of Earth Sciences St.Francis Xavier University Instituto Geolóogico y Minero de Espaa Ríos Rosas 2328003 MadridSpain School of Earth & Environmental Sciences University of Portsmouth Department of Earth Sciences University of Cambridge Downing StreetCambridge CB2 3EQUK

The Rheic Ocean was one of the most important oceans of the Paleozoic Era. It lay between Laurentia and Gondwana from the Early Ordovician and closed to produce the vast Ouachita- Alleghanian-Variscan orogen during the assembly of Pangea. Rifting began in the Cambrian as a continua- tion of Neoproterozoic orogenic activity and the ocean opened in the Early Ordovician with the separation of several Neoproterozoic arc terranes from the continental margin of northern Gondwana along the line of a former suture. The rapid rate of ocean opening suggests it was driven by slab pull in the outboard Iapetus Ocean. The ocean reached its greatest width with the closure of Iapetus and the accretion of the peri- Gondwanan arc terranes to Laurentia in the Silurian. Ocean closure began in the Devonian and continued through the Mississippian as Gondwana sutured to Laurussia to form Pangea. The ocean consequently plays a dominant role in the Appalachian-Ouachita orogeny of North America, in the basement geology of southern Europe, and in the Paleozoic sedimentary, structural and tectonothermal record from Middle America to the Middle East. Its closure brought the Paleozoic Era to an end.

关键词： Rheic Ocean Variscan-Alleghanian-Ouachita orogen Pangea North America Europe

Considerations for exerkine research focusing on the response to exercise training

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journal of Sport and Health Science 2024年第2期13卷 130-132页

作者： Ian A.j.Darragh brendan Egan School of Health and Human Performance Dublin City UniversityGlasnevinDublin D09 V209Ireland Florida Institute for Human and Machine Cognition PensacolaFL 32502USA

García-Hermoso and colleagues1 recently published a systematic literature review and meta-analysis on exercise training-induced changes in exerkine concentrations in type 2diabetes mellitus patients,providing a contemporary view on how exerkines respond to exercise *** review prompted us to highlight 2 additional considerations that should be taken into account when studying the response of exerkines to exercise ***,whether exerkines can exhibit discordant responses to acute exercise compared to exercise training,and secondly,the need to consider the residual effects of the most recent exercise bout.

关键词： acute exercise prompt

Testosterone treatment in older men： glass half empty or half full？

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Asian journal of Andrology 2017年第5期19卷 512-514页

作者： brendan j Nolan Mathis Grossmann Department of Endocrinology Austin HealthHeidelberg Victoria 3084 Australia Department of Medicine University of Melbourne Austin HealthHeidelberg Victoria 3084 Australia

In a series of randomized controlled trials published in jAMA and jAMA Intern Med,US researchers have examined the effect of testosterone treatment in older men with testosterone levels 〈275 ng dl^-1 on coronary arte... 详细信息

关键词： ELDERLY-MEN HYPOGONADISM

Understanding Performance for Two 802.11 Competing Flows

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journal of Computer Science & Technology 2008年第3期23卷 365-376页

作者： Michael j.Feeley brendan Cully Sharath j.George Department of Computer Science University of British ColumbiaVanconverCanada

It is well known that 802.11 suffers from both inefficiency and unfairness in the face of competition and interference. This paper provides a detailed analysis of the impact of topology and traffic type on network performance when two flows compete with each other for airspace. We consider both TCP and UDP flows and a comprehensive set of node topologies. We vary these topologies to consider all combinations of the following four node-to-node interactions：（1） nodes unable to read or sense each other, （2） nodes able to sense each other but not able to read each other＇s packets and nodes able to communicate with （3） weak and with （4） strong signal. We evaluate all possible cases through simulation and show that the cases can be reduced to 9 UDP and 10 TCP 802.11g models with similar efficiency/fairness characteristics. We also validate our simulation results with extensive experiments conducted in a laboratory testbed. These more detailed models improve on previous work such as hidden-/exposed-terminal categorization and are thus better suited as a basis for adaptive techniques to improve performance in 802.11 multi-hop WLAN or Mesh Networks.

关键词： 802.11 wireless unfairness two-flow competition network topology

Olfaction and reaction: The role of olfactory and hypothalamic investment in the antipredator responses to chemical alarm cues by northern redbelly dace

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Current Zoology 2023年第6期69卷 738-746页

作者： brendan j.joyce Grant E.Brown Department of Biology Concordia UniversityMontrealQuebecCanada

Neuroplasticity enables teleosts to promote or downregulate the growth of their brains *** compensate for the effects of predation pressure,teleosts may alter their brain morphology and behavioral responses to mitigate its impact on individual ***-predation environ-ments often promote specific patterns of brain growth and produce bolder and more proactive *** to the expense of maintaining neural tissue,relative size indicates the regions most relied *** northern redbelly dace Chrosomus eos,as little as 2 weeks of elevated predation pressure,resulted in increased investment in their olfactory bulbs and optic tecta,while the imposition of captivity produced smaller,less symmetric *** together,these results suggest that an individual could potentially become better able to detect a threat,and simultaneously less inclined to react to it,making the impact of either change in isolation is difficult to ***,we compared interindividual variation in gross brain morphology,risk-taking tactics in a novel arena(shy-bold personality),and responding to olfactory cues(proactive/reac-tive stress-coping style).We hypothesized that olfactory investment would positively correlate with response intensity to predator cue concen-tration and respond across a wider range of cue concentrations,while hypothalamus size would correlate with shyness and *** to heightened risk produced more bold/proactive individuals,with larger olfactory bulbs and smaller ***,the direction of the correlation between hypothalamus size and behavior varied by treatment,and olfactory investment only corresponded with response intensity amongst proactive *** findings illustrate the potential pitfalls of relating gross brain morphology to complex behavior and suggest that stress-coping style is a relevant consideration in future studies.

关键词： boldness brainmorphology neuroplasticity predation proactivity stress-coping style

Overhead shoulder press - In-front of the head or behind the head？

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journal of Sport and Health Science 2015年第3期4卷 250-257页

作者： Mark R. McKean brendan j. Burkett Faculty of Science Health and Education School of Health and Sport Sciences University of the Sunshine Coast Sippy Downs Queensland 4556 A ustralia

Background： Using a cross-sectional design comparison, two overhead press techniques （in-front of the head or behind the head） were compared. The purpose of this study was to determine the impact of behind the head or in-front of the head overhead pressing technique on shoulder range of movement （ROM） and spine posture. The overhead press is commonly prescribed exercise. The two techniques （in-front of the head or behind the head） may influence joint mechanics and therefore require an objective analysis. Methods： Passive shoulder ROM quantified using goniometric measures, dynamic ROM utilised three-dimensional （3D） biomechanical mea- sures （120 Hz） of 33 participants performing overhead pressing in a seated position. The timing and synchronisation of the upper limb shoulder and spine segments were quantified and influence of each technique was investigated. Results： The in-front technique commenced in lordotic position, whilst behind the head technique commenced in kyphotic position. Behind the head technique started with less thoracic extension than in-front condition. The thoracic spine remained extended and moved between 12~ and 15~ regardless of gender or technique. The techniques resulted in a significant difference between genders. Males were able to maintain a flat or normal lumbar lordosis, whereas females tended to kyphotic. Conclusion： Shoulder ROM was within passive ROM for all measures except external rotation for males with the behind the head technique. To avoid possible injury passive ROM should be increased prior to behind the head protocol. Females showed greater spine movements, suggesting trunk strengthening may assist overhead pressing techniques. For participants with normal trunk stability and ideal shoulder ROM, overhead pressing is a safe exercise （for the shoulder and spine） when performed either in-front of or behind the head.

关键词： 3RM Head ROM Shoulder flexibility Shoulder press Spine flexion

Increased β-Cyanoalanine Nitrilase Activity Improves Cyanide Tolerance and Assimilation in Arabidopsis

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Molecular Plant 2014年第1期7卷 231-243页

作者： brendan O'Leary GaU M. Preston Lee j. Sweetlove Department of Plant Sciences University of Oxford Oxford UK

Plants naturally produce cyanide （CN） which is maintained at low levels in their cells by a process of rapid assimilation. However, high concentrations of environmental CN associated with activities such as industrial pollution are toxic to plants. There is thus an interest in increasing the CN detoxification capacity of plants as a potential route to phytoremediation. Here, Arabidopsis seedlings overexpressing the Pseudomonas fluorescens β-cyanoalanine nitrilase pinA were compared with wild-type and a β-cyanoalanine nitrilase knockout line （△Atnit4） for growth in the presence of exogenous CN. After incubation with CN, ＋PfpinA seedlings had increased root length, increased fresh weight, and decreased leaf bleaching compared with wild-type, indicating increased CN tolerance. The increased tolerance was achieved without an increase in β-cyanoalanine synthase activity, the other enzyme in the cyanide assimilation pathway, suggesting that nitrilase activity is the limiting factor for cyanide detoxification. Labeling experiments with [^13C] KCN demonstrated that the altered CN tolerance could be explained by differences in flux from CN to Asn caused by altered β-cyanoalanine nitrilase activity. Metabolite profiling after CN treatment provided new insight into downstream metabolism, revealing onward metabolism of Asn by the photorespiratory nitrogen cycle and accumulation of aromatic amino acids.

关键词： cyanide β-cyanoalanine cyanide detoxification asparagine metabolism nitrilase