When the agroecological and respected childbirth paradigms do not find the expected appeal

Luego de desarrollar un extenso trabajo etnográfico en un distrito rural de la pampa húmeda argentina, en este trabajo se analizan los encuentros y, sobre todo, desencuentros producidos entre promotoras y destinatarias de dos políticas públicas. La primera promueve paradigmas de producción agraria agroecológica en un contexto de intenso riesgo ambiental por el uso de pesticidas. La segunda impulsa que las personas participantes busquen un parto "respetado” en el marco de campañas nacionales contra la violencia obstétrica. En ambos casos las ideas de "naturaleza” se asocian de forma émica con universos con intensos niveles de espiritualización e "ideologización” por parte de quienes las impulsan. Una parte importante de quienes reciben o "deberían” recibir dichas políticas innovadoras y alternativas, las ignoran, las rechazan o selas apropian de manera diferencial. Propongo entonces pensar la dimensión política de estos procesos en 3 niveles: viendo qué pasa con las destinatarias de dichas políticas públicas, qué sucede con las técnicas que las "ejecutan” y finalmente con quienes las estudiamos. En este sentido se critican miradas sociocéntricas provenientes del estado, de la academia y de algunos feminismos.After conducting an extensive ethnographic study in a rural district of the Argentine Pampas, I analyze the encounters and, above all, the misunderstandings between promoters and recipients of two public policies. The first one promotes agroecological agricultural production paradigms in a context of intense environmental risk due to the use of pesticides. The second encourages participants to seek a "respected" childbirth within the framework of national campaigns against obstetric violence. In both cases, the ideas of "nature" are associated in an emic way with universes with intense levels of spiritualization and "ideologization" on the part of those who promote the policies. Many of the recipients or intended recipients of such innovative and alternative policies, ignore them, reject them or appropriate them. I propose then to think about the political dimension of these processes at three levels: looking at what happens with the recipients of these public policies, what happens with the policies’ promoters and finally, with those of us who study them. In this sense, sociocentric views from the state, academia and some feminisms are criticized.Fil: Kunin, Johana R. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentin

Landscape impacts on pollinator communities in temperate systems: evidence and knowledge gaps

Summary 1. This review assesses current knowledge about the interplay between landscape and pollinator communities. Our primary aim is to provide an evidence base, identify key gaps in knowledge and highlight initiatives that will help develop and improve strategies for pollinator conservation. 2. Human-dominated landscapes (such as arable land and urban environments) can have detrimental impacts on pollinator communities but these negative effects can be ameliorated by proximity to semi-natural habitat and habitat corridors. There is also evidence to suggest that increased landscape heterogeneity and landscape configuration can play an important role in the maintenance of diverse pollinator communities. 3. Landscape characteristics have direct impacts on pollinator communities but can also influence abundance and richness through interaction with other drivers such as changing climate or increased chemical inputs in land management. 4. The majority of existing literature focuses on specific hymenopteran groups but there is a lack of information on the impact of landscape changes on non-bee taxa. Research is also needed on the effectiveness of management interventions for pollinators and multiple year observations are required for both urban and rural initiatives. 5. Current policies and monitoring schemes could contribute data that will plug gaps in knowledge, thus enabling greater understanding of relationships between landscapes and pollinator populations. This would in turn help design mitigation and adaptation strategies for pollinator conservation

The Cauchy problem for a class of two-dimensional nonlocal nonlinear wave equations governing anti-plane shear motions in elastic materials

This paper is concerned with the analysis of the Cauchy problem of a general class of two-dimensional nonlinear nonlocal wave equations governing anti-plane shear motions in nonlocal elasticity. The nonlocal nature of the problem is reflected by a convolution integral in the space variables. The Fourier transform of the convolution kernel is nonnegative and satisfies a certain growth condition at infinity. For initial data in $L^{2}$ Sobolev spaces, conditions for global existence or finite time blow-up of the solutions of the Cauchy problem are established.Comment: 15 pages. "Section 6 The Anisotropic Case" added and minor changes. Accepted for publication in Nonlinearit

Using exclusion rate to unify niche and neutral perspectives on coexistence

The competitive exclusion principle is one of the most influential concepts in ecology. The classical formulation suggests a correlation between competitor species similarity and competition severity, leading to rapid competitive exclusion where species are very similar; yet neutral models show that identical species can persist in competition for long periods. Here, we resolve the conflict by examining two components of similarity – niche overlap and competitive similarity – and modeling the effects of each on exclusion rate (defined as the inverse of time to exclusion). Studying exclusion rate, rather than the traditional focus on binary outcomes (coexistence vs exclusion), allows us to examine classical niche and neutral perspectives using the same currency. High niche overlap speeds exclusion, but high similarity in competitive ability slows it. These predictions are confirmed by a well-known model of two species competing for two resources. Under ecologically plausible scenarios of correlation between these two factors, the strongest exclusion rates may be among moderately similar species, while very similar and highly dissimilar competitors have very low exclusion rates. Adding even small amounts of demographic stochasticity to the model blurs the line between deterministic and probabilistic coexistence still further. Thus, focusing on exclusion rate, instead of on the binary outcome of coexistence versus exclusion, allows a variety of outcomes to result from competitive interactions. This approach may help explain species coexistence in diverse competitive communities and raises novel issues for future work

The Circumcision Issue

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68100/2/10.1177_000992289903800407.pd

Aerodynamical and Structural Analysis of Operationally Used Turbine Blades

This paper presents an integrated methodology for the analysis of operationally-used turbine blades, incorporating aerodynamic and multiple structural simulations. In jet engines, blade rubbing and erosion lead to deviations of the blade geometry. The presented functional simulations are conducted in order to predict the influence of wear on the performance of turbine blades based on these geometric variations. A numerical simulation of the investigated turbine blades using CFD show the change of aerodynamic performance and the flow field due to wear. Additionally, the deviations of the blade geometry lead to a different pressure and temperature distribution on the blade surface, which is used as input for the structural simulations. The change in geometry, surface pressure and temperature lead to a change in vibration behavior of the blade. Particularly the eigenfrequencies and excitation are affected. This is incorporated into the analysis by performing a structural vibration simulation of a complete bladed disk, using component mode synthesis and wave base substructuring. The mistuning effects are analyzed statistically using the Monte Carlo method. The change in vibration amplitudes influences crack opening and closing for a single blade under thermo-mechanical load. These processes, including thermal expansion, are investigated using the extended finite element method. Two real turbine blades are used to compare the characteristics of a new and a used blade.DFG/SFB/87

Conventional farming, education and children and youth: AACREA and Aapresid perspectives

El presente artículo analiza propuestas de carácter educativo y divulgativo dirigidas a poblaciones en edad escolar –incluyendo en particular aquellas radicadas en entornos rurales–, vinculadas con cuestiones productivas, ambientales y las llamadas "buenas prácticas agrícolas". Indagamos una selección de dispositivos generados por la Asociación Argentina de Consorcios Regionales de Experimentación Agrícola (AACREA) y por la Asociación Argentina de Productores en Siembra Directa (Aapresid), puestos a disposición a través de diversas plataformas en la última década, con énfasis en dos propuestas específicas. A través del análisis de contenido y la descripción densa, se aborda cómo se dan a conocer aspectos relativos a la agricultura convencional que se consideran poco o erróneamente difundidos. Es llamativo que la tecnología actualmente es tratada como potencial generadora de daños de suelos por “mal uso” y se reconoce públicamente, como mínimo, que en el pasado hubo cierta ingenuidad a la hora de evaluar las potencialidades que ofrecía. La mistificación del poder de la tecnología como estrategia se ve cotidianamente matizada, aunque su uso continúe siendo recomendado con fervor. Asimismo, los estudiantes no son impulsados a identificar que haya problemas sistémicos o estructurales para explicar estos temas.This article analyzes educational and communityoutreach proposals aimed at school-age populations -includingparticularly those living in rural areas-, related to productiveand environmental issues and the so-called "good agriculturalpractices". We studied a selection of initiatives created by theArgentine Association of Regional Consortiums of AgriculturalExperimentation (AACREA) and by the Argentine Associationof No Till Farmers (Aapresid), in the last decade. Throughcontent analysis and thick description, we addressed how aspectsrelated to conventional agriculture that are considered little orerroneously disseminated are made public. It is striking thatthe technology is currently treated as a potential generator ofsoil damage due to "misuse" and it is publicly acknowledged, atleast, that in the past there was a certain naivety in assessingthe potential it offered. The mystification of the power oftechnology as a strategy is daily nuanced, although its use continues to be recommended with fervor. Likewise, studentsare not encouraged to identify systemic or structural problemsto explain these issues.Fil: de Marco, Rosa María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Kunin, Johana R. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentin

The Mating System of the Wild-to-Domesticated Complex of Gossypium hirsutum L. Is Mixed

The domestication syndrome of many plants includes changes in their mating systems. The evolution of the latter is shaped by ecological and genetic factors that are particular to an area. Thus, the reproductive biology of wild relatives must be studied in their natural distribution to understand the mating system of a crop species as a whole. Gossypium hirsutum (upland cotton) includes both domesticated varieties and wild populations of the same species. Most studies on mating systems describe cultivated cotton as self-pollinated, while studies on pollen dispersal report outcrossing; however, the mating system of upland cotton has not been described as mixed and little is known about its wild relatives. In this study we selected two wild metapopulations for comparison with domesticated plants and one metapopulation with evidence of recent gene flow between wild relatives and the crop to evaluate the mating system of cotton’s wild-to-domesticated complex. Using classic reproductive biology methods, our data demonstrate that upland cotton presents a mixed mating system throughout the complex. Given cotton’s capacity for outcrossing, differences caused by the domestication process in cultivated individuals can have consequences for its wild relatives. This characterization of the diversity of the wild relatives in their natural distribution, as well as their interactions with the crop, will be useful to design and implement adequate strategies for conservation and biosecurity

Close Packing of Atoms, Geometric Frustration and the Formation of Heterogeneous States in Crystals

To describe structural peculiarities in inhomogeneous media caused by the tendency to the close packing of atoms a formalism based on the using of the Riemann geometry methods (which were successfully applied lately to the description of structures of quasicrystals and glasses) is developed. Basing on this formalism we find in particular the criterion of stability of precipitates of the Frank-Kasper phases in metallic systems. The nature of the ''rhenium effect'' in W-Re alloys is discussed.Comment: 14 pages, RevTex, 2 PostScript figure