5 resultados para Diamond, Jared: Collapse. How Societies Choose to Fail or Succeed
Resumo:
This expert review provides a detailed review of the academic evidence on how EU membership has influenced UK policies, systems of decision making and environmental quality. Containing 14 chapters and over 60,000 words, it documents how the EU has affected UK environmental policy and how, in turn, the UK has worked through the EU to shape wider, international thinking. It has been authored by 14 international experts, who have drawn on the findings of over 700 publications to offer an impartial and authoritative assessment of the evidence.
Resumo:
Displays are a feature of animal contest behaviour and have been interpreted as a means of gathering information on opponent fighting ability, as well as signalling aggressive motivation. In fish, contest displays often include frontal and lateral elements, which in the latter involves contestants showing their flanks to an opponent. Previous work in a range of fish species has demonstrated population-level lateralization of these displays, preferentially showing one side to their opponent. Mirrors are commonly used in place of a real opponent to study aggression in fish, yet they may disrupt the normal pattern of display behaviour. Here, using Siamese fighting fish, Betta splendens, we compare the aggressive behaviour of males to a mirror image and real opponent behind a transparent barrier. As this species is a facultative air-breather, we also quantify surface breathing, providing insights into underlying fight motivation. Consistent with previous work, we found evidence of population-level
lateralization, with a bias to present the left side and use the left eye when facing a real opponent. Contrary to expectations, there were no differences in the aggressive displays to a mirror and real opponent, with positive correlations between the behaviour in the two scenarios. However, there were important differences in surface breathing, which was more frequent and of longer duration in the mirror treatment. The reasons for these differences are discussed in relation to the repertoire of contest behaviour and motivation when facing a real opponent.
Resumo:
Displays are a feature of animal contest behaviour and have been interpreted as a means of gathering information on opponent fighting ability, as well as signalling aggressive motivation. In fish, contest displays often include frontal and lateral elements, which in the latter involves contestants showing their flanks to an opponent. Previous work in a range of fish species has demonstrated population-level lateralization of these displays, preferentially showing one side to their opponent. Mirrors are commonly used in place of a real opponent to study aggression in fish, yet they may disrupt the normal pattern of display behaviour. Here, using Siamese fighting fish, Betta splendens, we compare the aggressive behaviour of males to a mirror image and real opponent behind a transparent barrier. As this species is a facultative air-breather, we also quantify surface breathing, providing insights into underlying fight motivation. Consistent with previous work, we found evidence of population-level lateralization, with a bias to present the left side and use the left eye when facing a real opponent. Contrary to expectations, there were no differences in the aggressive displays to a mirror and real opponent, with positive correlations between the behaviour in the two scenarios. However, there were important differences in surface breathing, which was more frequent and of longer duration in the mirror treatment. The reasons for these differences are discussed in relation to the repertoire of contest behaviour and motivation when facing a real opponent.
Resumo:
We present a new approach to understand the landscape of supernova explosion energies, ejected nickel masses, and neutron star birth masses. In contrast to other recent parametric approaches, our model predicts the properties of neutrino-driven explosions based on the pre-collapse stellar structure without the need for hydrodynamic simulations. The model is based on physically motivated scaling laws and simple differential equations describing the shock propagation, the contraction of the neutron star, the neutrino emission, the heating conditions, and the explosion energetics. Using model parameters compatible with multi-D simulations and a fine grid of thousands of supernova progenitors, we obtain a variegated landscape of neutron star and black hole formation similar to other parametrized approaches and find good agreement with semi-empirical measures for the ‘explodability’ of massive stars. Our predicted explosion properties largely conform to observed correlations between the nickel mass and explosion energy. Accounting for the coexistence of outflows and downflows during the explosion phase, we naturally obtain a positive correlation between explosion energy and ejecta mass. These correlations are relatively robust against parameter variations, but our results suggest that there is considerable leeway in parametric models to widen or narrow the mass ranges for black hole and neutron star formation and to scale explosion energies up or down. Our model is currently limited to an all-or-nothing treatment of fallback and there remain some minor discrepancies between model predictions and observational constraints.
Resumo:
Background
Temper outbursts are prevalent in individuals with PWS and are often triggered by unexpected changes to routines or plans. However, such outbursts are also common in individuals with several other neurodevelopmental disorders, including those with a diagnosis of autism spectrum disorder (ASD). We compared the profile of temper outbursts in children with PWS to that in children with ASD. We examined whether differences in the temper outburst profile predicted differences in the outcomes of two caregiver led intervention strategies aiming to reduce change triggered outbursts.
Methods and results
Thirteen 7-15 year olds with PWS – taking part in a larger study involving 60 children evidencing temper outbursts following changes – were individually matched for age to children with ASD (mean ages: 10.70; 10.76 yrs). Caregivers participated in a structured/semi-structured interview on children's outbursts; completed a web-based outburst diary over a 6 month baseline; and are currently using either a change signalling intervention to reliably warn children of forthcoming changes; or a planning ahead intervention to reduce children's exposure to unexpected changes.
As reported at interview, on average, children with PWS showed more frequent temper outbursts than those with ASD (closer to daily vs. weekly). For seven children with PWS and six with ASD, 60% or more of their temper outbursts were reported to be triggered by changes. Whilst outbursts had similar durations when triggered by changes or by other events in children with PWS; change triggered outbursts in children with ASD were generally shorter. The most commonly reported outburst components in children with PWS included indicators of heightened emotional arousal but this was not the case for children with ASD. Data on behavioural change associated with each of the intervention strategies will be discussed.
Conclusions
Change triggered temper outbursts can be a problem for children PWS and ASD, however subtle differences appear to exist in the profile of these outbursts. Some of these differences may be relevant for the expected efficacy of different behavioural intervention strategies that target outbursts.
Summary
Temper outbursts (tantrums) were compared in children with PWS or autism spectrum disorder before and during use of one of two helping strategies. Helping strategies were led by caregivers and aimed to reduce outbursts that follow changes to routines or plans by making such changes more predictable, or by reducing the quantity of changes. Characteristics of outbursts may be important to help us predict which helping strategies may be most effective.