229 research outputs found

    Tracking pupil mobility over the pre-school and primary school period: evidence from EPPE 3-11

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    This report describes the ‘tracking’ of the EPPE 3-11 sample and then goes on to examine the possible influence of mobility on EPPE 3-11 children’s cognitive progress and social/behavioural development over both the pre-school and primary school period. In the present research ‘mobility’ is defined as having changed pre-school or school centre at least once. The aims of the research are: ‱ To determine possible means of reducing attrition in a longitudinal sample - tracking ‱ To identify any likely predictors of mobility, that is, whether mobile individuals share any defining characteristics; ‱ To investigate the effects of mobility when predicting children’s cognitive and social/behavioural outcomes, controlling for other background factors; ‱ To investigate the effects of children’s mobility in terms of the academic effectiveness of the schools attended and to which children moved

    Do fish go with the flow? The effects of periodic and episodic flow pulses on 0+ fish biomass in a constrained lowland river

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    The hydrological regime is a significant driver of fish population dynamics in rivers, but there is a dearth of information regarding the mechanisms behind its effects on temperate species, especially non-salmonids. This study investigated the effects of periodic and episodic flow pulses on 0+ fish biomass in a constrained lowland river. De-seasonalized cross-correlation analysis was used to examine time-lagged correlations in episodic signals, in isolation of seasonal periodicity, to identify the responses and response timings of 0+ fish production to abiotic variables, and whether apparent “pulse-depletions” in biomass occur instantaneously (e.g., due to fish displacement during high pulses) or after a time lag. As anticipated, 0+ fish biomass was highest during periods of low discharge and high temperatures in summer, but cross-correlation analysis revealed a negative impact of high pulses on 0+ fish biomass with a lag of 7 months. There was no evidence for an instantaneous pulse-depletion effect of discharge on 0+ fish biomass, suggesting that the indirect effects of high pulses, such as habitat or food-web modifications, are more influential

    Commercial fisheries in a mega unregulated floodplain river: assessment of the most favourable hydrological conditions for its preservation

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    This paper deals with the hydrological variability effects on the primary commercial fish species inhabiting the main channel and the floodplain of the large ParanĂĄ River in its middle reaches in Argentina. Analysing more than eight decades (1935–2016) of information on the most frequent and abundant commercial species in conjunction with hydrological levels and temperature, our results show that spring–summer floods of a certain magnitude (c. 6 m) and durations (> 80 days) are crucial for sustaining commercial fisheries. Moreover, the frequency of these floods was modulated by the decadal climatic fluctuations that have occurred over the past 100 years in the ParanĂĄ Basin. An insight into the probable incidence of some anthropogenic influences is also provided.Fil: Rabuffetti, Ana Pia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; ArgentinaFil: EspĂ­nola, Luis Alberto. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; ArgentinaFil: Abrial, Elie. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; ArgentinaFil: Amsler, Mario Luis. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; ArgentinaFil: Blettler, Martin Cesar Maria. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; ArgentinaFil: Eurich, MarĂ­a Florencia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; ArgentinaFil: Eberle Folmer, Eliana Gisel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂ­a. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂ­a; Argentin

    Effects of climate and land-use changes on fish catches across lakes at a global scale

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    Globally, our knowledge on lake fisheries is still limited despite their importance to food security and livelihoods. Here we show that fish catches can respond either positively or negatively to climate and land-use changes, by analyzing time-series data (1970–2014) for 31 lakes across five continents. We find that effects of a climate or land-use driver (e.g., air temperature) on lake environment could be relatively consistent in directions, but consequential changes in a lake-environmental factor (e.g., water temperature) could result in either increases or decreases in fish catch in a given lake. A subsequent correlation analysis indicates that reductions in fish catch was less likely to occur in response to potential climate and land-use changes if a lake is located in a region with greater access to clean water. This finding suggests that adequate investments for water-quality protection and water-use efficiency can provide additional benefits to lake fisheries and food security

    Mimicking human neuronal pathways in silico: an emergent model on the effective connectivity

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    International audienceWe present a novel computational model that detects temporal configurations of a given human neuronal pathway and constructs its artificial replication. This poses a great challenge since direct recordings from individual neurons are impossible in the human central nervous system and therefore the underlying neuronal pathway has to be considered as a black box. For tackling this challenge, we used a branch of complex systems modeling called artificial self-organization in which large sets of software entities interacting locally give rise to bottom-up collective behaviors. The result is an emergent model where each software entity represents an integrate-and-fire neuron. We then applied the model to the reflex responses of single motor units obtained from conscious human subjects. Experimental results show that the model recovers functionality of real human neuronal pathways by comparing it to appropriate surrogate data. What makes the model promising is the fact that, to the best of our knowledge, it is the first realistic model to self-wire an artificial neuronal network by efficiently combining neuroscience with artificial self-organization. Although there is no evidence yet of the model's connectivity mapping onto the human connectivity, we anticipate this model will help neuroscientists to learn much more about human neuronal networks, and could also be used for predicting hypotheses to lead future experiments
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