The rationales of resilience in English and Dutch flood risk policies

We compared the governance of flood risk in England and the Netherlands, focusing on the general policies, instruments used and underlying principles. Both physical and political environments are important in explaining how countries evolved towards very different rationales of resilience. Answering questions as ‘who decides’, ‘who should act’ and ‘who is responsible and liable for flood damage’ systematically, results in a quite fundamental difference in what resilience means, and how this affects the governance regime. In the Netherlands, there is nationwide collective regime with a technocracy based on the merit of water expertise, legitimated by a social contract of government being responsible and the general public accepting and supporting this. In England there also is a technocracy, but this is part of a general-political and economic-rational decision-making process, with responsibilities spread over state, insurance companies, individuals and communities. The rationales are connected to specific conceptions of the public interest, leading to specific governance principles. In both countries, flood risk strategies are discussed in the light of climate change effects, but resilience strategies show more persistence, although combined with gradual adaptation of practices on lower scales, than great transformations

Geometric changes allow normal ejection fraction despite depressed myocardial shortening in hypertensive left ventricular hypertrophy

Objectives.This study of hypertensive left ventricular hypertrophy 1) assessed myocardial shortening in both the circumferential and long-axis planes, and 2) investigated the relation between geometry and systolic function.Background.In hypertensive left ventricular hypertrophy, whole-heart studies have suggested normal systolic function on the basis of ejection fraction-systolic stress relations. By contrast, isolated muscle data show that contractility is depressed. It occurred to us that this discrepancy could be related to geometric factors (relative wall thickness).Methods.We studied 43 patients with hypertensive left ventricular hypertrophy and normal ejection fraction (mean ± SD 69 ± 13%) and 50 clinically normal subjects. By echocardiography, percent myocardial shortening was measured in two orthogonal planes; circumferential shortening was measured at the endocardium and at the midwall, and long-axis shortening was derived from mitral annular motion (apical four-chamber view). Circumferential shortening was related to end-systolic circumferential stress and long-axis shortening to meridional stress.Results.Endocardial circumferential shortening was higher than normal (42 ± 10% vs. 37 ± 5%, p < 0.01) and midwall circumferential shortening lower than normal in the left ventricular hypertrophy group (18 ± 3% vs. 21 ± 3%, p < 0.01). Differences between endocardial and midwall circumferential shortening are directly related to differences in relative wall thickness. Long-axis shortening was also depressed in the left ventricular hypertrophy group (18 ± 6% in the left ventricular hypertrophy group, 21 ± 5% in control subjects, p < 0.05). Midwall circumferential shortening and end-systolic circumferential stress relations in the normal group showed the expected inverse relation; those for ∼33% of the left ventricular hypertrophy group were >2 SD of normal relations, indicating depressed myocardial function. There was no significant relation between long-axis shortening and meridional stress, indicating that factors other than afterload influence shortening in this plane.Conclusions.High relative wall thickness allows preserved ejection fraction and normal circumferential shortening at the endocardium despite depressed myocardial shortening in two orthogonal planes

Needed: a systems approach to improve flood risk mitigation through private precautionary measures

Private precautionary measures play an increasingly important role in flood risk management. The degree to which private precautionary measures mitigate flood risk depends mainly on the type of measure (and how effective it is) and how frequently and successfully it is implemented. These aspects are influenced by a complex interaction of physical and socio-economic processes, which makes the assessment and the prediction of the mitigation of flood risk via private precautionary measures a challenge. This paper provides an overview of factors and processes that influence the implementation and effectiveness of private precaution in mitigating flood risk, underpinning it with highlights from international examples. We recommend private precautionary measures for further use to improve flood risk mitigation, but stress that they need to be considered and implemented through a holistic systems approach to maximize their effectiveness

Paraphrases and summaries: A means of clarification or a vehicle for articulating a preferred version of student accounts?

The use of group discussions as a means to facilitate learning from experiences is well documented in adventure education literature. Priest and Naismith (1993) assert that the use of the circular discussion method, where the leader poses questions to the participants, is the most common form of facilitation in adventure education. This paper draws on transcripts of facilitation sessions to argue that the widely advocated practice of leader summaries or paraphrases of student responses in these sessions functions as a potential mechanism to control and sponsor particular knowledge(s). Using transcripts from recorded facilitation sessions the analysis focuses on how the leader paraphrases the students’ responses and how these paraphrases or ‘formulations’ function to modify or exclude particular aspects of the students’ responses. I assert that paraphrasing is not simply a neutral activity that merely functions to clarify a student response, it is a subtle means by which the leader of the session can, often inadvertently or unknowingly, alter the student’s reply with the consequence of favouring particular knowledge(s). Revealing the subtle work that leader paraphrases perform is of importance for educators who claim to provide genuine opportunities for students to learn from their experience

‘Younger People Have Like More of an Imagination, No Offence’: Participant Perspectives on Public Engagement

© 2012, Copyright Taylor & Francis Group, LLC. A wide range of work has reported on the outcomes of public engagement activities and the views expressed by public participants towards specific areas of science and technology. Such work has rarely gone on to explore with public participants their attitudes to the engagement experienced itself, often focusing instead on more practical or quantifiable aspects. This article draws on public participants’ reactions to 11 ‘engagement’ events, occurring across the UK in 2007–2008. Reporting on 33 semi-structured interviews, we focus on their views of participation and engagement in terms of motivations, expectations and expertise. The results suggest that participants have considerable expectations in terms of information and interaction, operate with critical but respectful notions of other ‘publics’ and expertise, and may develop habitual tendencies regarding engagement

Solar Physics - Plasma Physics Workshop

A summary of the proceedings of a conference whose purpose was to explore plasma physics problems which arise in the study of solar physics is provided. Sessions were concerned with specific questions including the following: (1) whether the solar plasma is thermal or non-themal; (2) what spectroscopic data is required; (3) what types of magnetic field structures exist; (4) whether magnetohydrodynamic instabilities occur; (5) whether resistive or non-magnetohydrodynamic instabilities occur; (6) what mechanisms of particle acceleration have been proposed; and (7) what information is available concerning shock waves. Very few questions were answered categorically but, for each question, there was discussion concerning the observational evidence, theoretical analyses, and existing or potential laboratory and numerical experiments

Heating of the Solar Corona by Dissipative Alfven Solitons

Solar photospheric convection drives myriads of dissipative Alfven solitons (hereinafter called alfvenons) capable of accelerating electrons and ions to energies of hundreds of keV and producing the X-ray corona. Alfvenons are exact solutions of two-fluid equations for a collisionless plasma and represent natural accelerators for conversion of the electromagnetic energy flux driven by convective flows into kinetic energy of charged particles in space and astrophysical plasmas. Their properties have been experimentally verified in the magnetosphere, where they accelerate auroral electrons to tens of keV.Comment: 4 pages, 4 color figures, accepted for publication in Phys. Rev. Let

Magnetic Reynolds number dependence of reconnection rate and flow structure of the self-similar evolution model of fast magnetic reconnection

This paper investigates Magnetic Reynolds number dependence of the ``self-similar evolution model'' (Nitta et al. 2001) of fast magnetic reconnection. I focused my attention on the flow structure inside and around the reconnection outflow, which is essential to determine the entire reconnection system (Nitta et al. 2002). The outflow is consist of several regions divided by discontinuities, e.g., shocks, and it can be treated by a shock-tube approximation (Nitta 2004). By solving the junction conditions (e.g., Rankine-Hugoniot condition), the structure of the reconnection outflow is obtained. Magnetic reconnection in most astrophysical problems is characterized by a huge dynamic range of its expansion ($sim 10^7$ for typical solar flares) in a free space which is free from any influence of external circumstances. Such evolution results in a spontaneous self-similar expansion which is controlled by two intrinsic parameters: the plasma-$beta$ and the magnetic Reynolds number. The plasma-$beta$ dependence had been investigated in our previous paper. This paper newly clarifies the relation between the reconnection rate and the inflow structure just outside the Petschek-like slow shock: As the magnetic Reynolds number increases, strongly converging inflow toward the Petschek-like slow shock forms, and it significantly reduces the reconnection rate.Comment: 16 pages. to appear in ApJ (2006 Jan. 20 issue

Rapid dissipation of magnetic fields due to Hall current

We propose a mechanism for the fast dissipation of magnetic fields which is effective in a stratified medium where ion motions can be neglected. In such a medium, the field is frozen into the electrons and Hall currents prevail. Although Hall currents conserve magnetic energy, in the presence of density gradients, they are able to create current sheets which can be the sites for efficient dissipation of magnetic fields. We recover the frequency, $\omega_{MH}$, for Hall oscillations modified by the presence of density gradients. We show that these oscillations can lead to the exchange of energy between different components of the field. We calculate the time evolution and show that magnetic fields can dissipate on a timescale of order $1/\omega_{MH}$. This mechanism can play an important role for magnetic dissipation in systems with very steep density gradients where the ions are static such as those found in the solid crust of neutron stars.Comment: 9 pages, changed fig.

Patchy Reconnection in a Y-Type Current Sheet

We study the evolution of the magnetic field in a Y-type current sheet subject to a brief, localized magnetic reconnection event. The reconnection produces up- and down-flowing reconnected flux tubes which rapidly decelerate when they hit the Y-lines and underlying magnetic arcade loops at the ends of the current sheet. This localized reconnection outflow followed by a rapid deceleration reproduces the observed behavior of post-CME downflowing coronal voids. These simulations support the hypothesis that these observed coronal downflows are the retraction of magnetic fields reconnected in localized patches in the high corona.Comment: 4 pages, 3 figure