The Experts below are selected from a list of 135054 Experts worldwide ranked by ideXlab platform
M Haddon - One of the best experts on this subject based on the ideXlab platform.
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climate driven Range Extension of a sea urchin inferring future trends by analysis of recent population dynamics
Global Change Biology, 2009Co-Authors: S D Ling, K R Ridgway, Alistair J. Hobday, C R Johnson, M HaddonAbstract:Patterns of climate-forced Range shift in the marine environment are informed by investigating the population dynamics of an ecologically important sea urchin (Centrostephanus rodgersii– Diadematidae) across its newly extended Range in Tasmania (southeastern Australia). A growth model of C. rodgersii is developed allowing estimation of a sea urchin age profile and, in combination with abundance data, we correlate the sea urchin population dynamic with respect to environmental signals across the Range Extension region. Growth patterns did not vary across the Extension region; however, there was a strong pattern of decreasing sea urchin age with increasing distance from the historic Range. The sequential poleward discovery of the sea urchin, a pattern of declining age and a general poleward reduction in abundance along the eastern Tasmanian coastline are consistent with a model of Range Extension driven by recent change in patterns of larval dispersal. We explore this hypothesis by correlating C. rodgersii population characteristics with respect to the East Australian Current (EAC), i.e. the chief vector for poleward larval dispersal, and reveal patterns of declining sea urchin age and abundance with increasing distance from this oceanic feature. Furthermore, C. rodgersii is generally limited to sites where average winter temperatures are warmer than the cold threshold for its larval development. Potential dispersal and physiological mechanisms defining the Range Extension appear to be strongly coupled to the EAC which has undergone recent poleward advance and resulted in coastal warming in eastern Tasmania. Predicted climate change conditions for this region will favour continued population expansion of C. rodgersii not only via atmospheric-forced ocean warming, but also via ongoing intensification of the EAC driving continued poleward supply of larvae and heat.
Hayato Sumiya - One of the best experts on this subject based on the ideXlab platform.
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advanced safety Range Extension control system for electric vehicle with front and rear active steering and left and right force distribution
International Conference on Advanced Intelligent Mechatronics, 2012Co-Authors: Hiroshi Fujimoto, Hayato SumiyaAbstract:Mileage per charge is a critical issue for electric vehicles. To solve this issue, we have proposed a Range-Extension control system. Although it is effective for increasing the mileage per charge, it can potentially decrease vehicle stability because a driving force difference between the left and right motors is generated. In this paper, we introduce an advanced safety Range-Extension control system. The proposed method improves not only the cruise Range but also the vehicle stability on a curved road. The effectiveness of the proposed method is verified via experimental results.
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Range Extension control system of electric vehicle based on optimal torque distribution and cornering resistance minimization
IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society, 2011Co-Authors: Hiroshi Fujimoto, Hayato SumiyaAbstract:Recently, electric vehicles (EVs) have received substantial attention. However, EVs have several problems that prevent their widespread use. In particular, the cruising distance per charge is the most important parameter. In order to solve the problem of a short cruising Range, there have been many efforts to improve battery capacity. In contrast, in this paper, Range Extension control systems (RECSs) are proposed to enhance the efficiency based only on control technologies. Two types of Range Extension control systems are introduced, and their effectiveness is confirmed by experiments.
S D Ling - One of the best experts on this subject based on the ideXlab platform.
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climate driven Range Extension of a sea urchin inferring future trends by analysis of recent population dynamics
Global Change Biology, 2009Co-Authors: S D Ling, K R Ridgway, Alistair J. Hobday, C R Johnson, M HaddonAbstract:Patterns of climate-forced Range shift in the marine environment are informed by investigating the population dynamics of an ecologically important sea urchin (Centrostephanus rodgersii– Diadematidae) across its newly extended Range in Tasmania (southeastern Australia). A growth model of C. rodgersii is developed allowing estimation of a sea urchin age profile and, in combination with abundance data, we correlate the sea urchin population dynamic with respect to environmental signals across the Range Extension region. Growth patterns did not vary across the Extension region; however, there was a strong pattern of decreasing sea urchin age with increasing distance from the historic Range. The sequential poleward discovery of the sea urchin, a pattern of declining age and a general poleward reduction in abundance along the eastern Tasmanian coastline are consistent with a model of Range Extension driven by recent change in patterns of larval dispersal. We explore this hypothesis by correlating C. rodgersii population characteristics with respect to the East Australian Current (EAC), i.e. the chief vector for poleward larval dispersal, and reveal patterns of declining sea urchin age and abundance with increasing distance from this oceanic feature. Furthermore, C. rodgersii is generally limited to sites where average winter temperatures are warmer than the cold threshold for its larval development. Potential dispersal and physiological mechanisms defining the Range Extension appear to be strongly coupled to the EAC which has undergone recent poleward advance and resulted in coastal warming in eastern Tasmania. Predicted climate change conditions for this region will favour continued population expansion of C. rodgersii not only via atmospheric-forced ocean warming, but also via ongoing intensification of the EAC driving continued poleward supply of larvae and heat.
Scott D. Ling - One of the best experts on this subject based on the ideXlab platform.
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Exceeding the tipping point of Range-Extension meltdown
2016Co-Authors: Scott D. LingAbstract:Coincident with recent ocean warming there has been a dramatic and ongoing increase in the occurrence of warmer-water marine species in eastern Tasmania. While the ecological impact of these ‘Range-extending’ species remains largely ambiguous, the Extension of the sea urchin Centrostephanus rodgersii is leading to dramatic and persistent ecological change as urchin abundance exceeds the critical tipping-point of kelp bed overgrazing. Here I show how this collapsed urchin ‘barren’ reef state is subsequently triggering wholesale ‘tropicalization’ of reef fish communities in north eastern Tasmania; as revealed by comparing standardised underwater visual census of reef fishes in kelp beds and barrens sampled during the winters of 2002 and 2014. Over this period, overwhelming establishment of ‘warm-affinity’ reef fishes has occurred with the presence of only a single such species in 2002 increasing to a total of 13 in 2014, with 12 fishes establishing on barrens yet only 2 within kelp beds. Increases in the abundance of warm-affinity fishes also show similar trends and the overall consequences for ecological function are explored. Derived from the timing of standardised ‘first-sightings’ across eastern Tasmania over the past 17 years, rates of Range-Extension for reef fishes also match that of the urchin itself. In combination with prior research demonstrating the impact of ecological overfishing of sea urchin predators, the current findings redouble the importance of rebuilding local resilience to not only reduce risk of collapse for kelp beds and associated native biodiversity, but also to resist a Range-Extension ‘meltdown’ under a rapidly warming ocean.
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Pushing boundaries of Range and resilience: a review of Range-Extension by a barrens-forming sea urchin
2012Co-Authors: Scott D. LingAbstract:Pushing boundaries of Range and resilience: a review of Range-‐Extension by a barrens-‐forming sea urchin Scott D. Ling, Institute for Marine & Antarctic Studies, University of Tasmania, Hobart. Tas. 7001, Australia; email: Scott.Ling@utas.edu.au The barrens-‐forming sea urchin Centrostephanus rodgersii (Diadematidae) has undergone recent poleward Range-‐Extension to the Tasmanian coastline (SE Australia). By compiling field observations (including SST spanning >60yrs), broad-‐scale surveys and manipulative experiments conducted during the past decade, this review details knowledge on the response of this key sea urchin species to climate change and dually explores multiple processes influencing the ultimate ecological consequence of catastrophic-‐shift from productive kelp beds to urchin barrens, as now observed within the Range-‐Extension region. As a result of changing regional climate, eastern Tasmania has become increasingly suitable for Centrostephanus larval development with the timing of the sea urchins’ arrival, age-‐structure and spatial distribution across the Extension-‐region consistent with patterns in warming sea temperatures and current-‐driven dispersal potential. Furthermore, consistency in temperature dependency of larval development plus lack of genetic differentiation of the species across its entire Range, confirm the critical role of changing climate in driving the Range-‐Extension. Continued warming predicted for this region will favour increased larval survival, promoting ongoing population expansion and ultimately increased likelihood of populations reaching sufficient density to affect widespread overgrazing. As such, knowledge of patterns and mechanisms promoting overgrazing are also reviewed for the purpose of identifying kelp beds at greatest risk given climate trends, reef substratum types and predator abundance (chiefly spiny lobsters) as influenced by intense fishing pressure. Finally, this review shows how management of non-‐climatic local scale stressors can be used to increase resilience of kelp beds against overgrazing given large-‐scale climate-‐driven increases in key sea urchin populations.
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Genetic structure of a recent climate change-driven Range Extension.
Molecular ecology, 2010Co-Authors: Sam C. Banks, Scott D. Ling, Craig R. Johnson, Maxine P. Piggott, Jane E. Williamson, Luciano B. BeheregarayAbstract:The life-history strategies of some species make them strong candidates for rapid exploitation of novel habitat under new climate regimes. Some early-responding species may be considered invasive, and negatively impact on �na�ve� ecosystems. The barrensforming sea urchin Centrostephanus rodgersii is one such species, having a high dispersal capability and a high-latitude Range margin limited only by a developmental temperature threshold. Within this species� Range in eastern Australian waters, sea temperatures have increased at greater than double the global average rate. The coinciding poleward Range Extension of C. rodgersii has caused major ecological changes, threatening reef biodiversity and fisheries productivity. We investigated microsatellite diversity and population structure associated with Range expansion by this species. Generalized linear model analyses revealed no reduction in genetic diversity in the newly colonized region. A �seascape genetics� analysis of genetic distances found no spatial genetic structure associated with the Range Extension. The distinctive genetic characteristic of the Extension zone populations was reduced population-specific FST, consistent with very rapid population expansion. Demographic and genetic simulations support our inference of high connectivity between pre- and post-Extension zones. Thus, the Range shift appears to be a poleward Extension of the highly-connected Rangewide population of C. rodgersii. This is consistent with advection of larvae by the intensified warm water East Australian current, which has also increased Tasmanian Sea temperatures above the species� lower developmental threshold. Thus, ocean circulation changes have improved the climatic suitability of novel habitat for C. rodgersii and provided the supply of recruits necessary for colonization.
Hiroshi Fujimoto - One of the best experts on this subject based on the ideXlab platform.
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advanced safety Range Extension control system for electric vehicle with front and rear active steering and left and right force distribution
International Conference on Advanced Intelligent Mechatronics, 2012Co-Authors: Hiroshi Fujimoto, Hayato SumiyaAbstract:Mileage per charge is a critical issue for electric vehicles. To solve this issue, we have proposed a Range-Extension control system. Although it is effective for increasing the mileage per charge, it can potentially decrease vehicle stability because a driving force difference between the left and right motors is generated. In this paper, we introduce an advanced safety Range-Extension control system. The proposed method improves not only the cruise Range but also the vehicle stability on a curved road. The effectiveness of the proposed method is verified via experimental results.
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Range Extension control system of electric vehicle based on optimal torque distribution and cornering resistance minimization
IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society, 2011Co-Authors: Hiroshi Fujimoto, Hayato SumiyaAbstract:Recently, electric vehicles (EVs) have received substantial attention. However, EVs have several problems that prevent their widespread use. In particular, the cruising distance per charge is the most important parameter. In order to solve the problem of a short cruising Range, there have been many efforts to improve battery capacity. In contrast, in this paper, Range Extension control systems (RECSs) are proposed to enhance the efficiency based only on control technologies. Two types of Range Extension control systems are introduced, and their effectiveness is confirmed by experiments.
