663 research outputs found
The energy benefits of the pantograph wing mechanism in flapping flight:Case study of a gull
Bird wings generally contain a 4-bar pantograph mechanism in the forearm that enables the wrist joint to be actuated from the elbow joint thus reducing the number of wing muscles and hence reducing the wing inertia and inertial drag. In this paper we develop a theoretical model of inertial power for flapping flight to estimate the advantage of the 4-bar pantograph mechanism by comparing the inertial power required for the case where wrist muscles are present in the forearm with the case where wrist muscles are not present in the forearm. It is difficult to predict how wrist muscles would look when there is no pantograph mechanism. Therefore a lower bound and upper bound case are defined. The lower bound case involves redistributing the elbow muscles with no increase in wing mass. The upper bound case involves replicating the biceps-triceps muscles near the wrist joint. At minimum power speed the model estimates that the 4-bar pantograph mechanism reduces the inertial power for the gull from between 6.1%–12.3% and reduces the overall power by 0.6%–1.2%. When account is taken of the tight margins involved in the design of a flying vehicle, the energy savings produced by the pantograph mechanism are significant. A ring-billed gull was chosen for the case study and an adult specimen was obtained to gather morphometric data. Lessons for the design of flapping micro air vehicles are discussed. </jats:p
Towards understanding interactions between Sustainable Development Goals: the role of environment–human linkages
Only 10 years remain to achieve all Sustainable Development Goals (SDGs) globally, so there is a growing need to increase the effectiveness and efficiency of action by targeting multiple SDGs. The SDGs were conceived as an ‘indivisible whole’, but interactions between SDGs need to be better understood. Several previous assessments have begun to explore interactions including synergies and possible conflicts between the SDGs, and differ widely in their conclusions. Although some highlight the role of the more environmentally-focused SDGs in underpinning sustainable development, none specifically focuses on environment-human linkages. Assessing interactions between SDGs, and the influence of environment on them, can make an important contribution to informing decisions in 2020 and beyond.
Here, we review previous assessments of interactions among SDGs, apply an influence matrix to assess pairwise interactions between all SDGs, and show how viewing these from the perspective of environment-human linkages can influence the outcome.
Environment, and environment-human linkages, influence most interactions between SDGs. Our action-focused assessment enables decision makers to focus environmental management to have the greatest impacts, and to identify opportunities to build on synergies and reduce trade-offs between particular SDGs. It may enable sectoral decision makers to seek support from environment managers for achieving their goals.
We explore cross-cutting issues and the relevance and potential application of our approach in supporting decision making for progress to achieve the SDGs
'The heart of what we do': policies on teaching, learning and assessment in the learning and skills sector
One of the stated aims of government policy in England is to put teaching, training,and learning at the heart of the learning and skills system. This paper provides a critical review of policies on teaching, learning and assessment in the learning and skills sector over the past five years. It draws upon data collected and analysed in the early stages of an ESRC-funded Teaching and Learning Research Programme project. Using evidence from policy sources, we argue that despite policy rhetoric about devolution of responsibility to the 'front line', the dominant 'images' that government has of putting teaching, learning and assessment at the heart of the Learning and Skills Sector involves a narrow concept of learning and skills; an idealisation of learner agency lacking an appreciation of the pivotal role of the learner/tutor relationship and a top-down view of change in which central government agencies are relied on to secure education standards
Inhibition and young children's performance on the Tower of London task
Young children, when performing problem solving tasks, show a tendency to break task rules and produce incomplete solutions. We propose that this tendency can be explained by understanding problem solving within the context of the development of “executive functions” – general cognitive control functions, which serve to regulate the operation of the cognitive system. This proposal is supported by the construction of two computational models that simulate separately the performance of 3–4 year old and 5–6 year old children on the Tower of London planning task. We seek in particular to capture the emerging role of inhibition in the older group. The basic framework within which the models are developed is derived from Fox and Das’ Domino model [Fox, J., & Das, S. (2000). Safe and sound: Artificial intelligence in hazardous applications. Cambridge, MA: MIT Press] and Norman and Shallice’s [Norman, D.A., & Shallice, T. (1986). Attention to action: Willed and automatic control of behaviour. In R. Davidson, G. Schwartz, & D. Shapiro (Eds.), Consciousness and Self Regulation (Vol. 4). New York: Plenum] theory of willed and automatic action. Two strategies and a simple perceptual bias are implemented within the models and comparisons between model and child performance reveal a good fit for the key dependent measures (number of rule breaks and percentage of incomplete solutions) of the two groups
The Lyth Bound and the End of Inflation
We derive an extended version of the well-known Lyth Bound on the total
variation of the inflaton field, incorporating higher order corrections in slow
roll. We connect the field variation to both the spectral index of
scalar perturbations and the amplitude of tensor modes. We then investigate the
implications of this bound for ``small field'' potentials, where the field
rolls off a local maximum of the potential. The total field variation during
inflation is {\em generically} of order , even for potentials with
a suppressed tensor/scalar ratio. Much of the total field excursion arises in
the last e-fold of inflation and in single field models this problem can only
be avoided via fine-tuning or the imposition of a symmetry. Finally, we discuss
the implications of this result for inflationary model building in string
theory and supergravity.Comment: 10 pages, RevTeX, 2 figures (V3: version accepted for publication by
JCAP
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Global goals mapping: the environment-human landscape
The UK Natural Environment Research Council (NERC), The Rockefeller Foundation (RF), and the UK Economic and Social Research Council (ESRC) recognise that the development challenges of the 21st century require both a shift in thinking and actions that prepare us for the future, while enabling more effective development interventions today. These organisations are establishing a new initiative: 'Towards a Sustainable Earth: Environment-human Systems and the UN Global Goals' (TaSE) as part of their commitment to seeing the 17 Sustainable Development Goals (also known as Global Goals) become a reality. The core premise of the TaSE initiative is that environment-human interactions must be central to all development.
The TaSE initiative is convening a meeting at The Rockefeller Foundation Bellagio Centre (7-11 November 2016) to identify the major research and innovation questions relevant to the achievement of the overarching ambition of this initiative. To help focus discussions during this meeting, NERC commissioned the Sussex Sustainability Research Programme (SSRP) at the University of Sussex and the UN Environment World Conservation Monitoring Centre (UNEP-WCMC) to produce a “synthesis of past and current research and innovation relating to the policy landscape surrounding the environment-human relationships and systems that interact across the UN Global Goals”.
The commissioned work is encapsulated in this report, Global Goals mapping: the environment-human landscape. For each Goal, the first part of this report summarises the role of environment-human interactions and synthesises relevant research evidence, key innovations and policies, and knowledge and research gaps.
The syntheses of research evidence, key innovations and policies presented for individual Global Goals show that environment-human interactions are important for the achievement of all of the Goals. However, the number of environment-human interactions, and the extent to which these interactions need to be considered for achieving each Goal, varies among Global Goals. Although research, innovation and policy have advanced substantially since the Millennium Ecosystem Assessment, knowledge and research gaps related to environment-human interactions remain for all Goals.
The Global Goals were conceived as an 'indivisible whole'. The Goals relate to and depend on each other, but relationships between Goals need to be better understood. Previous analyses have begun to explore relationships including synergies and possible conflicts between the Goals from a number of different perspectives and differ widely in their conclusions. While many highlight the role of the more environmentally-focused Goals in underpinning sustainable development, none specifically focuses on environment-human interactions, which are the focus of the TaSE initiative and crucial to the achievement of the Goals.
This report uses a new analysis to suggest which relationships between Global Goals may be most influenced by environment-human interactions. It is based on a pairwise view of relationships between Goals, assessing the influence that action (research, policy, innovation and/or management) towards one Goal may have on the potential for achieving others. It highlights 20 pairwise relationships between Goals where these influences may be especially strong, and illustrates for some of these how the knowledge and research gaps identified in Part 1 are relevant to the relationships between the Goals. In reality relationships among Goals are more complex and multidimensional than a pairwise analysis can illustrate, but visualising all connections among them is challenging. Further knowledge gaps and challenges related to the trade-offs, synergies and unintended consequences of the relationships among Goals will need to be addressed to achieve all 17 Goals.
In order to understand relationships among Global Goals and prioritize action, including research, it is essential to consider multiple cross-cutting factors, including: temporal and spatial scales of action and impact; context for the action, whether local or other; the (multi) directionality of the relationships among Goals; thresholds and tipping points; number and types of people affected; human behaviour; governance, institutions and power; existence and accessibility of different types of knowledge; and the feasibility of obtaining and scaling-up research results and innovations by 2030. Several approaches have attempted to tackle interconnected challenges, including nexus thinking, pathways, leverage points, indigenous and local knowledge, integrated environmental assessments and integrated modelling. However, there is a need for more work and holistic approaches to achieve all 17 Goals.
The syntheses of research evidence, innovations and policies regarding environment-human interactions relevant to each Global Goal and the analysis of the relationships among Goals provide a basis for identifying priority areas for new research, innovation and policy. The Bellagio Group has a vital role to play in building on this to help the TaSE initiative identify a research, innovation and research translation agenda in support of the Global Goals
Density functional theory studies of MTSL nitroxide side chain conformations attached to an activation loop
A quantum-mechanical (QM) method rooted on density functional theory (DFT) linked to the Stochastic Liouville equation (SLE) in the Fokker Planck (FP) form has been employed for the first time to sample the methane-thiosulfonate spin label (MTSL) conformational space attached to the Aurora-A kinase activation loop and to calculate the EPR spectrum. The features of the calculated energy surface allowed us to describe the system in a limited number of rotamers stabilized by interactions of the MTSL side chain and neighbouring residues. The relevant magnetic parameters and the electron paramagnetic resonance (EPR) spectrum were subsequently calculated from the trajectories of the spin probe in the protein environment. The comparison between theoretical and experimental continuous wave (CW) EPR spectra revealed some small differences in the EPR line shape which arises from the combinations of g- and A-values obtained from the conformations selected. The theoretical approach adopted in this work can be used to recognise the contribution of MTSL rotamers to the EPR spectrum in order to help extract structural/dynamics properties of protein from the experimental data
Genome wide screens in yeast to identify potential binding sites and target genes of DNA-binding
Cosmology From Random Multifield Potentials
We consider the statistical properties of vacua and inflationary trajectories
associated with a random multifield potential. Our underlying motivation is the
string landscape, but our calculations apply to general potentials. Using
random matrix theory, we analyze the Hessian matrices associated with the
extrema of this potential. These potentials generically have a vast number of
extrema. If the cross-couplings (off-diagonal terms) are of the same order as
the self-couplings (diagonal terms) we show that essentially all extrema are
saddles, and the number of minima is effectively zero. Avoiding this requires
the same separation of scales needed to ensure that Newton's constant is stable
against radiative corrections in a string landscape. Using the central limit
theorem we find that even if the number of extrema is enormous, the typical
distance between extrema is still substantial -- with challenging implications
for inflationary models that depend on the existence of a complicated path
inside the landscape.Comment: revtex, 3 figures, 10 pages v2 refs adde
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