595 research outputs found

    ParticleTracker: a gui based particle tracking software

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    Tracking the motion of objects in a video is an important part of the analysis in a diverse range of subject disciplines (Meijering, 2012; Rahman, 2019; Rose, 2020). It enables one to automate the extraction of quantitative information about size, shape, motion etc. A number of tracking softwares exist (Bradski, 2000; D. B. Allan, 2020; J. Tineveza, 2016) to help with this process but the code can be an entry barrier. Even for researchers with the necessary skills, developing the code and optimising the parameters requires a significant investment for each new project. Open source tools that can simplify and expedite this process, whilst remaining flexible and easy to extend by the end user, would help to make particle tracking accessible to a broader range of researchers

    Place matters: but does local leadership?

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    The arrival of New Labour into Government witnessed the prominent re-emergence of place onto the policy agenda. This heralded a range of area-based-initiatives designed to both tackle neighbourhood forms of deprivation and to re-establish a sense of identity and connection between individuals and their local community. In terms of place-making, effective and inclusive participation, representation and leadership were all identified as prerequisites for the creation of sustainable communities . But how important is local leadership and strategic vision within local public service organisations in achieving the desired place-making outcomes? This paper examines the extent to which local leadership and strategic vision represents a significant factor in promoting higher levels of satisfaction, belonging, cohesion and participation across single tier councils in England. The ensuing empirical evidence raises significant questions not only about the importance of local leadership in place-making, but also the environmental and organizational factors that shape local places

    On the short term stability and tilting motion of a well-observed low-latitude solar coronal hole

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    The understanding of the solar magnetic coronal structure is tightly linked to the shape of open field regions, specifically coronal holes. A dynamically evolving coronal hole coincides with the local restructuring of open to closed magnetic field, which leads to changes in the interplanetary solar wind structure. By investigating the dynamic evolution of a fast-tilting coronal hole, we strive to uncover clues about what processes may drive its morphological changes, which are clearly visible in EUV filtergrams. Using combined 193A and 195A EUV observations by AIA/SDO and EUVI/STEREO_A, in conjunction with line-of-sight magnetograms taken by HMI/SDO, we track and analyze a coronal hole over 12 days to derive changes in morphology, area and magnetic field. We complement this analysis by potential field source surface modeling to compute the open field structure of the coronal hole. We find that the coronal hole exhibits an apparent tilting motion over time that cannot solely be explained by solar differential rotation. It tilts at a mean rate of ~3.2{\deg}/day that accelerates up to ~5.4{\deg}/day. At the beginning of May, the area of the coronal hole decreases by more than a factor of three over four days (from ~13 * 10^9 km^2 to ~4 * 10^9 km^2), but its open flux remains constant (~2 * 10^20 Mx). Further, the observed evolution is not reproduced by modeling that assumes the coronal magnetic field to be potential. In this study, we present a solar coronal hole that tilts at a rate that has yet to be reported in literature. The rate exceeds the effect of the coronal hole being advected by either photospheric or coronal differential rotation. Based on the analysis we find it likely that this is due to morphological changes in the coronal hole boundary caused by ongoing interchange reconnection and the interaction with a newly emerging ephemeral region in its vicinity.Comment: Accepted in A&A September 15, 2023; 10 pages, 8 figure

    Self-interest And Public Interest: The Motivations Of Political Actors

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    Self-Interest and Public Interest in Western Politics showed that the public, politicians, and bureaucrats are often public spirited. But this does not invalidate public-choice theory. Public-choice theory is an ideal type, not a claim that self-interest explains all political behavior. Instead, public-choice theory is useful in creating rules and institutions that guard against the worst case, which would be universal self-interestedness in politics. In contrast, the public-interest hypothesis is neither a comprehensive explanation of political behavior nor a sound basis for institutional design

    Pulsar Constraints on Neutron Star Structure and Equation of State

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    With the aim of constraining the structural properties of neutron stars and the equation of state of dense matter, we study sudden spin-ups, glitches, occurring in the Vela pulsar and in six other pulsars. We present evidence that glitches represent a self-regulating instability for which the star prepares over a waiting time. The angular momentum requirements of glitches in Vela indicate that at least 1.4% of the star's moment of inertia drives these events. If glitches originate in the liquid of the inner crust, Vela's `radiation radius' must exceed ~12 km for a mass of 1.4 solar masses. Observational tests of whether other neutron stars obey this constraint will be possible in the near future.Comment: 5 pages, including figures. To appear in Physical Review Letter

    The geomorphology of the Anthropocene:emergence, status and implications

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    This is the peer reviewed version of the following article: BROWN, A.G. ... et al, 2017. The geomorphology of the Anthropocene: emergence, status and implications. Earth Surface Processes and Landforms, 42(1), pp.71-90., which has been published in final form at http://dx.doi.org/10.1002/esp.3943. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The Anthropocene is proposed as a new interval of geological time in which human influence on Earth and its geological record dominates over natural processes. A major challenge in demarcating the Anthropocene is that the balance between human-influenced and natural processes varies over spatial and temporal scales owing to the inherent variability of both human activities (as associated with culture and modes of development) and natural drivers (e.g. tectonic activity and sea level variation). Against this backdrop, we consider how geomorphology might contribute towards the Anthropocene debate focussing on human impact on aeolian, fluvial, cryospheric and coastal process domains, and how evidence of this impact is preserved in landforms and sedimentary records. We also consider the evidence for an explicitly anthropogenic geomorphology that includes artificial slopes and other human-created landforms. This provides the basis for discussing the theoretical and practical contributions that geomorphology can make to defining an Anthropocene stratigraphy. It is clear that the relevance of the Anthropocene concept varies considerably amongst different branches of geomorphology, depending on the history of human actions in different process domains. For example, evidence of human dominance is more widespread in fluvial and coastal records than in aeolian and cryospheric records, so geomorphologically the Anthropocene would inevitably comprise a highly diachronous lower boundary. Even to identify this lower boundary, research would need to focus on the disambiguation of human effects on geomorphological and sedimentological signatures. This would require robust data, derived from a combination of modelling and new empirical work rather than an arbitrary ‘war of possible boundaries’ associated with convenient, but disputed, `golden spikes’. Rather than being drawn into stratigraphical debates, the primary concern of geomorphology should be with the investigation of processes and landform development, so providing the underpinning science for the study of this time of critical geological transition

    Absence of lattice strain anomalies at the electronic topological transition in zinc at high pressure

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    High pressure structural distortions of the hexagonal close packed (hcp) element zinc have been a subject of controversy. Earlier experimental results and theory showed a large anomaly in lattice strain with compression in zinc at about 10 GPa which was explained theoretically by a change in Fermi surface topology. Later hydrostatic experiments showed no such anomaly, resulting in a discrepancy between theory and experiment. We have computed the compression and lattice strain of hcp zinc over a wide range of compressions using the linearized augmented plane wave (LAPW) method paying special attention to k-point convergence. We find that the behavior of the lattice strain is strongly dependent on k-point sampling, and with large k-point sets the previously computed anomaly in lattice parameters under compression disappears, in agreement with recent experiments.Comment: 9 pages, 6 figures, Phys. Rev. B (in press

    Science and Ideology in Economic, Political, and Social Thought

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    This paper has two sources: One is my own research in three broad areas: business cycles, economic measurement and social choice. In all of these fields I attempted to apply the basic precepts of the scientific method as it is understood in the natural sciences. I found that my effort at using natural science methods in economics was met with little understanding and often considerable hostility. I found economics to be driven less by common sense and empirical evidence, then by various ideologies that exhibited either a political or a methodological bias, or both. This brings me to the second source: Several books have appeared recently that describe in historical terms the ideological forces that have shaped either the direct areas in which I worked, or a broader background. These books taught me that the ideological forces in the social sciences are even stronger than I imagined on the basis of my own experiences. The scientific method is the antipode to ideology. I feel that the scientific work that I have done on specific, long standing and fundamental problems in economics and political science have given me additional insights into the destructive role of ideology beyond the history of thought orientation of the works I will be discussing

    Planning for Sustainability in Small Municipalities: The Influence of Interest Groups, Growth Patterns, and Institutional Characteristics

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    How and why small municipalities promote sustainability through planning efforts is poorly understood. We analyzed ordinances in 451 Maine municipalities and tested theories of policy adoption using regression analysis.We found that smaller communities do adopt programs that contribute to sustainability relevant to their scale and context. In line with the political market theory, we found that municipalities with strong environmental interests, higher growth, and more formal governments were more likely to adopt these policies. Consideration of context and capacity in planning for sustainability will help planners better identify and benefit from collaboration, training, and outreach opportunities
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