Environmental study of ERTS-1 imagery: Lake Champlain and Vermont

Environmental concerns of the State of Vermont currently being stressed include water quality in Lake Champlain and a state-wide land use and capability plan. Significant results obtained from ERTS-1 relate directly to the above concerns. Industrial water pollution and turbidity in Lake Champlain have been identified and mapped and the ERTS pollution data will be used in the developing court suit which Vermont has initiated against the polluters. ERTS imagery has also provided a foundation for updating and revising land use inventories. Major classes of land use have been identified and mapped, and substantial progress has been made toward the mapping of such land use divisions as crop and forest type, and wetlands

Directed percolation in aerodynamics: resolving laminar separation bubble on airfoils

In nature, phase transitions prevail amongst inherently different systems, while frequently showing a universal behavior at their critical point. As a fundamental phenomenon of fluid mechanics, recent studies suggested laminar-turbulent transition belonging to the universality class of directed percolation. Beyond, no indication was yet found that directed percolation is encountered in technical relevant fluid mechanics. Here, we present first evidence that the onset of a laminar separation bubble on an airfoil can be well characterized employing the directed percolation model on high fidelity particle image velocimetry data. In an extensive analysis, we show that the obtained critical exponents are robust against parameter fluctuations, namely threshold of turbulence intensity that distinguishes between ambient flow and laminar separation bubble. Our findings indicate a comprehensive significance of percolation models in fluid mechanics beyond fundamental flow phenomena, in particular, it enables the precise determination of the transition point of the laminar separation bubble. This opens a broad variety of new fields of application, ranging from experimental airfoil aerodynamics to computational fluid dynamics.Comment: 8 pages, 11 figure

Reducing Violence in a Time of Global Uncertainty: Insights from the Institute of Development Studies Addressing and Mitigating Violence Programme

This Evidence Report details key insights from the Institute of Development Studies Addressing and Mitigating Violence programme, which involved detailed political analysis of dynamics of violence as well as efforts to reduce and prevent violent conflict across a number of countries and areas in sub-Saharan Africa, the Middle East and South Asia. In particular, the evidence highlighted here is from violent settings that do not neatly fit categories of ‘war’ or ‘peace’. The findings of these studies, published as a series of open-access reports, Policy Briefings and blogs, were discussed by conflict and security experts as well as thinkers from aid and advocacy organisations at a consultative session in London in November 2015. This report uses evidence from the programme to critically reflect on policy and programming policy approaches for reducing violence. Specifically, it provides a synthesis of findings around these themes: (1) the nature of violence and how it might be changing; (2) the connectivity of actors across levels and space; and (3) the significance of identities and vulnerabilities for understanding and responding to violence. The report concludes by examining the implications of the research for the violence reduction paradigm.UK Department for International Developmen

Reducing Violence in a Time of Global Uncertainty

The new Sustainable Development Goal to reduce armed violence is a welcome commitment but the prescriptive nature of its approach is problematic – there is ‘no one size fits all’. Rather, focus needs to be on how violence operates in particular settings. Evidence from IDS’ Addressing and Mitigating Violence programme highlights the need to pursue bespoke approaches to tackling violence. We must recognise how different types of violence interlink and reinforce each other; how transnational and local-level actors involved with violence connect and operate; and how democratic spaces, and agency, need support and consideration for the pursuit of peaceful outcomes.UK Department for International Developmen

The role of sensory parameters in predicting clinical outcome after lumbar discectomy

Background: Lumbar discectomy is considered a safe, efficacious and cost-effective treatment for selected cases of patients with leg pain associated with the presence of a disc protrusion. But despite technically successful surgery, 30 % of patients complain of persistent pain on long-term follow up. Identification of possible predictors for a negative outcome is important, in the search for appropriate pre- and/or post-operative care and prevention of persistent disability. There is some evidence in the literature that quantitative sensory testing (QST) measures may play a role in prediction of patients’ pain persistency, however, this has never been investigated in patients undergoing lumbar discectomy. Objective: The aim of this study is to determine the predictive value of QST parameters, in combination with previously documented predictor variables such as medical/psychological/cognitive behavioural factors, in patients with lumbar radiculopathy and/or radicular pain, for predicting patients’ clinical outcome after lumbar discectomy. Method: Participants with radiculopathy and/or radicular pain and confirmed imaging diagnosis of nerve root compression will be recruited from the elective surgery waitlist at one hospital. All participants will undergo lumbar discectomy performed by one neurosurgeon. A standardized QST protocol comprising all of the somatosensory sub-modalities that are mediated by different primary afferents (C-, Aδ-, Aβ-) will be performed prior to surgery. QST will be conducted in the patients’ main pain area and contralateral side, in the affected dermatome and at a remote control site. The presence of other predictor variables will be captured by questionnaires. Follow-up at 3 months will include QST and measurements of pain intensity, pain descriptors, functional status, health related quality of life, return to work and health care utilisation. A further 1-year follow-up will include the same measurements except QST. Results/Conclusions: Identification of new predictor variables may assist in the development of pre-surgical screening methods and in targeted pre- and/or post-operative patient care, with the potential to improve patients’ functional status, quality of life, work capacity whilst also reducing health care costs associated with persistent disability

Electrodynamic Radiation Reaction and General Relativity

We argue that the well-known problem of the instabilities associated with the self-forces (radiation reaction forces) in classical electrodynamics are possibly stabilized by the introduction of gravitational forces via general relativity

Superdiffusion of massive particles induced by multi-scale velocity fields

We study drag-induced diffusion of massive particles in scale-free velocity fields, where superdiffusive behavior emerges due to the scale-free size distribution of the vortices of the underlying velocity field. The results show qualitative resemblance to what is observed in fluid systems, namely the diffusive exponent for the mean square separation of pairs of particles and the preferential concentration of the particles, both as a function of the response time.Comment: 5 pages, 5 figures. Accepted for publication in EP

Spectral Simplicity of Apparent Complexity, Part II: Exact Complexities and Complexity Spectra

The meromorphic functional calculus developed in Part I overcomes the nondiagonalizability of linear operators that arises often in the temporal evolution of complex systems and is generic to the metadynamics of predicting their behavior. Using the resulting spectral decomposition, we derive closed-form expressions for correlation functions, finite-length Shannon entropy-rate approximates, asymptotic entropy rate, excess entropy, transient information, transient and asymptotic state uncertainty, and synchronization information of stochastic processes generated by finite-state hidden Markov models. This introduces analytical tractability to investigating information processing in discrete-event stochastic processes, symbolic dynamics, and chaotic dynamical systems. Comparisons reveal mathematical similarities between complexity measures originally thought to capture distinct informational and computational properties. We also introduce a new kind of spectral analysis via coronal spectrograms and the frequency-dependent spectra of past-future mutual information. We analyze a number of examples to illustrate the methods, emphasizing processes with multivariate dependencies beyond pairwise correlation. An appendix presents spectral decomposition calculations for one example in full detail.Comment: 27 pages, 12 figures, 2 tables; most recent version at http://csc.ucdavis.edu/~cmg/compmech/pubs/sdscpt2.ht