Piecewise Constant Policy Approximations to Hamilton-Jacobi-Bellman Equations

An advantageous feature of piecewise constant policy timestepping for Hamilton-Jacobi-Bellman (HJB) equations is that different linear approximation schemes, and indeed different meshes, can be used for the resulting linear equations for different control parameters. Standard convergence analysis suggests that monotone (i.e., linear) interpolation must be used to transfer data between meshes. Using the equivalence to a switching system and an adaptation of the usual arguments based on consistency, stability and monotonicity, we show that if limited, potentially higher order interpolation is used for the mesh transfer, convergence is guaranteed. We provide numerical tests for the mean-variance optimal investment problem and the uncertain volatility option pricing model, and compare the results to published test cases

Precision weed control in sunflower and maize - experiences from Hungary

In recent years, a Hungarian private farm in Zimany (Southern Hungary) systematically built-up and developed its spatial information infrastructure and enabled us to carry out research on and development of site-specific weed management methods. Over the past four years, our goals were to improve weed control efficacy and to reduce the amount of herbicides applied. We a) developed an off-line, map-based method for pre-emergent precision herbicide treatments to control weeds in maize and sunflower (our application algorithm is based on the humus content and an empirical plasticity index of the soil), and b) in on-line precision post-emergent inrow treatments in maize we used a novel approach to mount mechanically shielded WeedSeeker (NTech Industries) sensor-sprayers on a precision cultivator (Garford Farm Machinery) in order to apply a non-selective (total) herbicide (glyphosate) safely under the leaf canopy. Keywords: GPS, herbicides, precision agriculture, sensor-sprayers, site-specific weed management Präzise Unkrautkontrolle in Sonnenblume und Mais - Erfahrungen aus UngarnIn den letzten Jahren hat ein privater landwirtschaftlicher Betrieb in Zimány (Südungarn) seine räumliche Geoinformations-Infrastruktur deutlich verbessert und die Durchführung der Forschung und Entwicklung von Methoden zur teilflächenspezifischen Unkrautmanagement ermöglicht. In den letzten vier Jahren entwickelten wir eine kartenbasierte Methode (Off-line) für a) Vorauflauf- Präzisionsherbizidbehandlungen in Mais und Sonnenblumen (der angewendete Algorithmus basiert auf dem Humus- und Sandgehalt des Bodens) und für b) Nachauflauf- Präzisionsherbizidanwendungen in Reihen-Kulturen, die eine zwei-Komponenten- Herbizidkombination mit variabler Zusammensetzung verwendet (die Dosis und der Anteil der Herbizide ist dichtebasiert). In Online-Präzisionsbehandlungen für Nachauflauf-Unkraut in Mais haben wir WeedSeeker (NTech Industries, USA) Sprühgeräte verwendet, um die Herbizide unter dem Blätterdach anzuwenden. Stichwörter: GPS, ortsspezifische Unkrautbekämpfung, teilflächenspezifische Landwirtschaf

Results of the study of cross-resistance and effect of herbicide on crops in the production of cycloxydim-tolerant maize (Zea mays L)

In Hungary, monocot weed species are present as a signiἀcant yield limiting factor. In practice there is a great demand for efἀciently applying agrochemicals against monocot weeds at a later period and without causing phy totoxicity. Field trials were carried out in 2010 and 2011. The trials aimed to understand whether the cycloxydim-tolerant (CT) maize have cross-resistance to herbicides expressing different graminicide action (quizalofop-p-tefuril, haloxyfop-r-methyl ester, propaquizalofop, Ḁuazifop-p-butyl). The obtained results conἀrm that CT maize has signiἀcant tolerance to cycloxydim active substance. Lower rates of other types of graminicides neither damage maize plants nor reduce the yield, while application of higher rates used to control perennial weeds do. According to the authors’ conclusions, no other types of graminicides can be used to perform chemical weed control in CT maize. Post-emergent use of cycloxydim showed excellent efἀcacy against monocot weeds: Echinochloa crusgalli, Setaria verticillata, Panicum miliaceum. It is well-known that growing genetically modiἀed maize is greatly restricted in Europe, therefore the published scientiἀc results provide good option for the control of monocot weeds in the maize growing areas

Basic comparison of particle size distribution measurements of pigments and fillers using commonly available industrial methods

The Nanobiosciences Unit of the Joint Research Centre’s Institute for Health and Consumer Protection and Eurocolour, the association of European pigments, dyes and fillers industry, have carried out a program of work to evaluate a number of instrumental methods of measuring particle size distributions as required for assessing compliance versus the EU Recommendation for the definition on nanomaterials. The study has examined the use of five instrumental methods applied to a range of eight widely different but industrially relevant powder pigments. The techniques examined were Laser Diffraction (LD), Dynamic Light Scattering (DLS), Centrifugal Liquid Sedimentation (CLS), Volume Specific Surface Area (VSSA) and Electron Microscopy (EM). This report describes the materials studied and the preparative and analytical methods used. Individual chapters provide an overview of the single analytical methods used together with a summary of the results obtained using each particular method. In considering the results of this study it is important to note that the aim was not to determine the optimum conditions for every individual sample but rather to produce and evaluate data which could be considered representative of that obtainable in industrial laboratories using existing instrumental facilities operated by experienced but not specialised operators. The report discusses the challenges of using these instrumental methods to obtain a simple unambiguous classification of the test materials according to the EC definition.JRC.I.4-Nanobioscience

Recovery and resilience of urban stream metabolism following Superstorm Sandy and other floods

Urban streams are exposed to multiple different stressors on a regular basis, with increased hydrological flashiness representing a common urban stream stressor. Stream metabolism, the coupled ecosystem functions of gross primary production (GPP) and ecosystem respiration (ER), controls numerous other ecosystem functions and integrates multiple processes occurring within streams. We examined the effect of one large (Superstorm Sandy) and multiple small and moderately sized flood events in Baltimore, Maryland, to quantify the response and recovery of urban stream GPP and ER before and after floods of different magnitudes. We also compared GPP and ER before and after Superstorm Sandy to literature values. We found that both GPP and ER decreased dramatically immediately following floods of varying magnitudes, but on average GPP was more reduced than ER (80% and 66% average reduction in GPP and ER, respectively). Both GPP and ER recovered rapidly following floods within 4–18 d, and recovery intervals did not differ significantly between GPP and ER. During the two-week recovery following Superstorm Sandy, two urban streams exhibited a range of metabolic activity equivalent to ~15% of the entire range of GPP and ER reported in a recent meta-analysis of stream metabolism. Urban streams exhibit a substantial proportion of the natural variation in metabolism found across stream ecosystems over relatively short time scales. Not only does urbanization cause increased hydrological flashiness, it appears that metabolic activity in urban streams may be less resistant, but also more resilient to floods than in other streams draining undeveloped watersheds, which have been more studied. Our results show that antecedent conditions must be accounted for when drawing conclusions about stream metabolism measurements, and the rapid recovery and resilience of urban streams should be considered in watershed management and stream restoration strategies targeting ecosystem functions and services

Terrestrial mammal three-dimensional photogrammetry : multispecies mass estimation

Assessing body mass in mammals is of importance as it influences virtually all aspects of mammal physiology, behavior and ecological parameters. However, the assessment of body mass of large mammals is potentially dangerous and logistically challenging. Photogrammetry (measurements through the use of photographs) is a well-established science. In zoology it has been used with varying success to estimate the size and mass of some marine and terrestrial mammal species. However, photogrammetric body mass estimation of terrestrial mammals has received comparatively little attention. This is largely due to species’ variable morphological attributes which complicates measurement especially if, for 3D orientation, photogrammetric models are dependent on identifiable features on the animals themselves. Ninety-two individuals belonging to 16 terrestrial mammalian species were weighed and photographed for body mass estimation using a volumetric photogrammetry method, purposely applied with commercially available software. This method is not dependent on identifiable body features for 3D orientation. Measured body mass ranged from 25 kg to 4060 kg. Photogrammetric mass estimates versus physically weighed mass was plotted and the goodness of fit assessed for each species. Body size, shape and physiological attributes influence the accuracy of body mass estimation between species (although consistent within species), largely attributed to morphological features (e.g., hair length and posture). This photogrammetric method accurately estimated the body mass of several terrestrial mammal species. It represents innovative use of photographs to create calibrated three-dimensional imagery for accurate quantification of mammalian metrics, specifically body volume and mass. Advances of a method that is not subject to species, sex or age is advantageous and suitable for wide application in our effort to model population demography.The Department of Science and Technology via the National Research Foundation (NRF) and the University of Pretoria.http://www.esajournals.orgam2016Mammal Research Institut

Rethinking Measures of Democracy and Welfare State Universalism: Lessons from Subnational Research

Democracy and the welfare state are two of the most extensively studied concepts and themes in the field of comparative politics. Debate about how to best measure the two concepts has failed to contemplate the extent to which political and social rights are uniformly present across distinct regions of the national territory, despite the presence of substantial subnational research that underscores wide variation inside countries. We argue that this omission hampers our understanding of the two phenomena and we propose a new measure of democracy and healthcare unversalism, which we call the Adjusted Measures of Democracy and Welfare Universalism. The new measures integrate territorial inequality into existing national-level indicators, providing a more accurate picture of country performance and opening the door to new, multi-level theory building

Marine ecosystem assessment for the Southern Ocean: birds and marine mammals in a changing climate

The massive number of seabirds (penguins and procellariiformes) and marine mammals (cetaceans and pinnipeds) – referred to here as top predators – is one of the most iconic components of the Antarctic and Southern Ocean. They play an important role as highly mobile consumers, structuring and connecting pelagic marine food webs and are widely studied relative to other taxa. Many birds and mammals establish dense breeding colonies or use haul-out sites, making them relatively easy to study. Cetaceans, however, spend their lives at sea and thus aspects of their life cycle are more complicated to monitor and study. Nevertheless, they all feed at sea and their reproductive success depends on the food availability in the marine environment, hence they are considered useful indicators of the state of the marine resources. In general, top predators have large body sizes that allow for instrumentation with miniature data-recording or transmitting devices to monitor their activities at sea. Development of scientific techniques to study reproduction and foraging of top predators has led to substantial scientific literature on their population trends, key biological parameters, migratory patterns, foraging and feeding ecology, and linkages with atmospheric or oceanographic dynamics, for a number of species and regions. We briefly summarize the vast literature on Southern Ocean top predators, focusing on the most recent syntheses. We also provide an overview on the key current and emerging pressures faced by these animals as a result of both natural and human causes. We recognize the overarching impact that environmental changes driven by climate change have on the ecology of these species. We also evaluate direct and indirect interactions between marine predators and other factors such as disease, pollution, land disturbance and the increasing pressure from global fisheries in the Southern Ocean. Where possible we consider the data availability for assessing the status and trends for each of these components, their capacity for resilience or recovery, effectiveness of management responses, risk likelihood of key impacts and future outlook