Learning form Nature to improve the heat generation of iron-oxide nanoparticles for magnetic hyperthermia applications.

The performance of magnetic nanoparticles is intimately entwined with their structure, mean size and magnetic anisotropy. Besides, ensembles offer a unique way of engineering the magnetic response by modifying the strength of the dipolar interactions between particles. Here we report on an experimental and theoretical analysis of magnetic hyperthermia, a rapidly developing technique in medical research and oncology. Experimentally, we demonstrate that single-domain cubic iron oxide particles resembling bacterial magnetosomes have superior magnetic heating efficiency compared to spherical particles of similar sizes. Monte Carlo simulations at the atomic level corroborate the larger anisotropy of the cubic particles in comparison with the spherical ones, thus evidencing the beneficial role of surface anisotropy in the improved heating power. Moreover we establish a quantitative link between the particle assembling, the interactions and the heating properties. This knowledge opens new perspectives for improved hyperthermia, an alternative to conventional cancer therapies.

A Literature Review of Urban Bypass Studies, 1992

Urban places attract most highway travel because more people are to be per acre in urban places than elsewhere. In the beginning of highway development the objective was to provide an all-weather road for the rural people to get to town and back to their farms, but there was no consideration of getting motor vehicles through the town to the opposite side. With the development of intercity travel, it soon became apparent that travel through the urban areas would have to be given consideration along with the travel to and from the urban areas. This consideration led to the urban bypass, a provision in highway location whereby the traveler may get to the opposite side of the urban area without going through it, or at least not through the central business district. Bypasses, although highly desired by the through travelers, were not welcomed by local business interests on the basis that the community would suffer a reduction in retail trade. Some discussion of the pros and cons of bypasses and their consequences as observed from experience will shed light upon this type of local highway. The bypass report summaries in this document were based on interviews with businessmen and community leaders of cities that have actually experienced firsthand the impacts of a highway bypass. Several of the studies were conducted by newspaper reporters, city council members and residents of Iowa cities.

An Assessment of Traffic Safety in Urban Deer Herd Management Zones in Iowa, 2010

Many states are striving to keep their deer population to a sustainable and controllable level while maximizing public safety. In Iowa, measures to control the deer population include annual deer hunts and special deer herd management plans in urban areas. While these plans may reduce the deer population, traffic safety in these areas has not been fully assessed. Using deer population data from the Iowa Department of Natural Resources and data on deer-vehicle crashes and deer carcass removals from the Iowa Department of Transportation, the authors examined the relationship between deer-vehicle collisions, deer density, and land use in three urban areas in Iowa that have deer management plans in place (Cedar Rapids, Dubuque, and Iowa City) over the period 2002 to 2007. First, a comparison of deer-vehicle crash counts and deer carcass removal counts was conducted at the county level. Further, the authors estimated econometric models to investigate the factors that influence the frequency and severity of deer-vehicle crashes in these zones. Overall, the number of deer carcasses removed on the primary roads in these counties was greater than the number of reported deervehicle crashes on those roads. These differences can be attributed to a number of reasons, including variability in data reporting and data collection practices. In addition, high rates of underreporting of crashes were found on major routes that carry high volumes of traffic. This study also showed that multiple factors affect deer-vehicle crashes and corresponding injury outcomes in urban management zones. The identified roadway and non-roadway factors could be useful for identifying locations on the transportation system that significantly impact deer species and safety and for determining appropriate countermeasures for mitigation. Efforts to reduce deer density adjacent to roads and developed land and to provide wider shoulders on undivided roads are recommended. Improving the consistency and accuracy of deer carcass and deer-vehicle collision data collection methods and practices is also desirable.

Emergence of Swiss metropole and scaling properties of urban clusters

Defining the limits of an urban agglomeration is essential both for fundamental and applied studies in quantitative and theoretical geography. A simple and consistent way for defining such urban clusters is important for performing different statistical analysis and comparisons. Traditionally, agglomerations are defined using a rather qualitative approach based on various statistical measures. This definition varies generally from one country to another, and the data taken into account are different. In this paper, we explore the use of the City Clustering Algorithm (CCA) for the agglomeration definition in Switzerland. This algorithm provides a systemic and easy way to define an urban area based only on population data. The CCA allows the specification of the spatial resolution for defining the urban clusters. The results from different resolutions are compared and analysed, and the effect of filtering the data investigated. Different scales and parameters allow highlighting different phenomena. The study of Zipf's law using the visual rank-size rule shows that it is valid only for some specific urban clusters, inside a narrow range of the spatial resolution of the CCA. The scale where emergence of one main cluster occurs can also be found in the analysis using Zipf's law. The study of the urban clusters at different scales using the lacunarity measure - a complementary measure to the fractal dimension - allows to highlight the change of scale at a given range.

Vers une gestion de la nature en termes d'action publique : analyse d'une dynamique d'appropriation des ressources végétales à Tobré, Nord Bénin

Cette étude se fonde sur des recherches ethnographiques menées autour de la mise en oeuvre d'une politique publique de gestion de la nature à Tobré, une région baatonu au Bénin. L'étude se place dans une dynamique d'appropriation des ressources naturelles en rapport avec l'entrée en jeu de multiples acteurs publics et privés dans l'arène locale de gestion de la nature. En effet, ces acteurs ont acquis ces dernières années de l'expérience et de l'efficacité à la faveur des changements institutionnels et politiques et s'incluent davantage dans le processus de décision au point de suppléer l'Etat dans les actions qui étaient ses prérogatives. L'étude met en lumière les rapports de conflits, de compétitions, de concurrence ou de compromis autour des enjeux sociaux, politiques et économiques de protection de la nature. Elle décrit et analyse les formes d'interactions entre les différents acteurs individuels, collectifs et institutionnels, afin de voir en quoi ces interactions participent du processus de mobilisation d'acteurs locaux et de confrontation de vision, qui finalement définit et oriente les politiques locales de protection de la nature. Pour atteindre cet objectif, l'étude mobilise des apports théoriques de plusieurs disciplines, notamment de la socio- anthropologie du développement, de l'histoire et de la sociologie politique. Elle repose également sur des données empiriques collectées à partir d'une combinaison d'outils techniques, des entretiens et des observations jusqu'au dépouillement de presse et des études de cas. Les principaux résultats montrent que les acteurs locaux, particulièrement les comités de gestion sont parvenus à inscrire la gestion des ressources naturelles dans l'espace public à travers les débats dans les médias, les forums, les marches de protestation, etc. De fait, ils ont été capables d'influer sur le processus de définition et de mise en oeuvre des politiques locales de protection de la nature et donc de reconfigurer l'arène locale de gestion des ressources naturelles. Ce qui amène l'Etat et ses services déconcentrés, en premier lieu les services des Eaux et Forêts et la mairie à pactiser avec ces différents comités, sans pour autant perdre de leur notoriété. Au contraire, ils participent de la gouvernance de l'ensemble des actions et permettent de mettre en place des formes de gestion négociée. - This is an ethnographic research on the implementation of a public policy for the management of natural resources in Tobre, a baatonu village in Benin. The study focuses on the dynamic of natural resources ownership in a context of multiple stakeholders in the public and private sectors. In recent years, these stakeholders have become more experienced and efficient as a result of several institutional and policy changes. The stakeholders are more involved in the decision making process to the point that they can complement the role of the State in natural resources management. This study highlights the conflicts, competition, or compromise associated with the social, political and economic constraints of nature conservation. The interactions between individual, collective and institutional stakeholders were analyzed, to understand their role in the process of mobilizing local stakeholders and confronting their visions. This process ultimately defines and guides local policies on the management of nature. To achieve this goal, this study combined theoretical approaches from developmental socio-anthropology, history and political sociology with empirical data collected using interviews, observations, newspapers analysis and case studies. The results show that local stakeholders, particularly the management committees, were successful at introducing the need for sustainable natural resource management in the mainstream public discourse through the media, forums, and demonstrations. They were able to influence the process of identifying and implementing local policies on nature conservancy. This has encouraged the State, through its forestry services, and the district mayors to collaborate with these committees in the shared governance of natural resources.

Fate of the herbicide glyphosate and its metabolite AMPA in soils and their transfer to surface waters: A multi-scale approach in the Lavaux vineyards, western Switzerland

The use of herbicides in agriculture may lead to environmental problems, such as surface water pollution, with a potential risk for aquatic organisms. The herbicide glyphosate is the most used active ingredient in the world and in Switzerland. In the Lavaux vineyards it is nearly the only molecule applied. This work aimed at studying its fate in soils and its transfer to surface waters, using a multi-scale approach: from molecular (10-9 m) and microscopic scales (10-6 m), to macroscopic (m) and landscape ones (103 m). First of all, an analytical method was developed for the trace level quantification of this widely used herbicide and its main by-product, aminomethylphosphonic acid (AMPA). Due to their polar nature, their derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) was done prior to their concentration and purification by solid phase extraction. They were then analyzed by ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The method was tested in different aqueous matrices with spiking tests and validated for the matrix effect correction in relevant environmental samples. Calibration curves established between 10 and 1000ng/l showed r2 values above 0.989, mean recoveries varied between 86 and 133% and limits of detection and quantification of the method were as low as 5 and 10ng/l respectively. At the parcel scale, two parcels of the Lavaux vineyard area, located near the Lutrive River at 6km to the east of Lausanne, were monitored to assess to which extent glyphosate and AMPA were retained in the soil or exported to surface waters. They were equipped at their bottom with porous ceramic cups and runoff collectors, which allowed retrieving water samples for the growing seasons 2010 and 2011. Results revealed that the mobility of glyphosate and AMPA in the unsaturated zone was likely driven by the precipitation regime and the soil characteristics, such as slope, porosity structure and layer permeability discrepancy. Elevated glyphosate and AMPA concentrations were measured at 60 and 80 cm depth at parcel bottoms, suggesting their infiltration in the upper parts of the parcels and the presence of preferential flow in the studied parcels. Indeed, the succession of rainy days induced the gradual saturation of the soil porosity, leading to rapid infiltration through macropores, as well as surface runoff formation. Furthermore, the presence of more impervious weathered marls at 100 cm depth induced throughflows, the importance of which for the lateral transport of the herbicide molecules was determined by the slope steepness. Important rainfall events (>10 mm/day) were clearly exporting molecules from the soil top layer, as indicated by important concentrations in runoff samples. A mass balance showed that total loss (10-20%) mainly occurred through surface runoff (96%) and, to a minor extent, by throughflows in soils (4%), with subsequent exfiltration to surface waters. Observations made in the Lutrive River revealed interesting details of glyphosate and AMPA dynamics in urbanized landscapes, such as the Lavaux vineyards. Indeed, besides their physical and chemical properties, herbicide dynamics at the catchment level strongly depend on application rates, precipitation regime, land use and also on the presence of drains or constructed channels. Elevated concentrations, up to 4970 ng/l, observed just after the application, confirmed the diffuse export of these compounds from the vineyard area by surface runoff during main rain events. From April to September 2011, a total load of 7.1 kg was calculated, with 85% coming from vineyards and minor urban sources and 15% from arable crops. Small vineyard surfaces could generate high concentrations of herbicides and contribute considerably to the total load calculated at the outlet, due to their steep slopes (~10%). The extrapolated total amount transferred yearly from the Lavaux vineyards to the Lake of Geneva was of 190kg. At the molecular scale, the possible involvement of dissolved organic matter (DOM) in glyphosate and copper transport was studied using UV/Vis fluorescence spectroscopy. Combined with parallel factor (PARAFAC) analysis, this technique allowed characterizing DOM of soil and surface water samples from the studied vineyard area. Glyphosate concentrations were linked to the fulvic-like spectroscopic signature of DOM in soil water samples, as well as to copper, suggesting the formation of ternary complexes. In surface water samples, its concentrations were also correlated to copper ones, but not in a significant way to the fulvic-like signature. Quenching experiments with standards confirmed field tendencies in the laboratory, with a stronger decrease in fluorescence intensity for fulvic-like fluorophore than for more aromatic ones. Lastly, based on maximum concentrations measured in the river, an environmental risk for these compounds was assessed, using laboratory tests and ecotoxicity data from the literature. In our case and with the methodology applied, the risk towards aquatic species was found negligible (RF<1).

Education on Urban Corridor Issues Through Computer Animation, TR-419, 2003

This project was undertaken in coordination with the Environmental Assessment process on the Mt. Vernon Road Improvements project in Cedar Rapids, Iowa. The goal of the research was to determine the cost effectiveness of combined photo-imaging and computer animation as a presentation tool describing public road improvements. The Public Hearing, in combination with the involvement of a Citizen's Resource Group, afforded an opportunity to have an evaluation of the processes by interested citizens who were not familiar with engineering drawings or the construction industry. After the initial viewing of a draft version of the video, the Resource Group made recommendations to the staff developing the video. Discussion of these recommendations led to the development of an animated composite section that showed a combination of situations typically encountered throughout the project corridor, as well as critical considerations. The composite section did not show specific locations and therefore, individuals were not distracted by looking for the details pertaining to their properties. Concentration on the concepts involved rather than specifics provided the opportunity for a more thorough understanding by the citizens. The development of the composite concept was the primary discovery of the research.