Overview of the Worldwide Spread of Conservation Agriculture

The global empirical evidence shows that farmer-led transformation of agricultural production systems based on Conservation Agriculture (CA) principles is already occurring and gathering momentum globally as a new paradigm for the 21st century. The data presented in this paper has been collected by the Food and Agriculture Organization of the United Nations from several sources including estimates made by ministries of agriculture, by farmer organizations, and well-informed individuals in research or development organizations; they provide an overview of CA adoption and spread by country, as well as the extent of CA adoption by continent. CA systems, comprising no or minimum mechanical soil disturbance, organic mulch soil cover, and crop species diversification, in conjunction with other good practices of crop and production management, are now (in 2013) practiced globally on about 157 M ha, corresponding to about 11% of field cropland, in all continents and most land-based agricultural ecologies, including in the various temperate environments. This change constitutes a difference of some 47% globally since 2008/09 when the spread was recorded as 106 M ha. The current total of 157 M ha represents an increase in adoption of CA by more countries but the estimate is on the conservative side as the updated database does not capture all the CA cropland. While in 1973/74 CA systems covered only 2.8 M ha worldwide, the area had grown in 1999, to 45 M ha, and by 2003 the area had grown to 72 M ha. In the last 10 years CA cropland has expanded at an average rate of more than 8.3 M ha per year and since 2008/2009 at the rate of some 10 M ha per year, showing the increased interest of farmers and national governments in this alternate production concept and method. Adoption has been intense mainly in North and South America as well as in Australia and Asia, and more recently in Europe and Africa where the awareness of and support for CA is on the increase. The paper presents an update of the adoption of CA since 2008/09.Au vu des données empiriques mondiales, la transformation des systèmes de production agricole, qui s’appuient sur les principes de l’Agriculture de Conservation (AC), conduite par les agriculteurs eux-mêmes, est déjà engagée et s’impose peu à peu comme un nouveau modèle mondial pour le 21ème siècle. Les données de cet article ont été recueillies par l'Organisation des Nations Unies pour l’Alimentation et l’Agriculture (FAO) auprès de plusieurs sources et sont notamment issues d'études réalisées par des ministères de l'agriculture, des organisations d'agriculteurs et des experts d'organismes de recherche et développement ; elles donnent un aperçu par pays et par continent du niveau d’adoption et de progression de l’AC. Les pratiques de l’AC, qui englobent la perturbation mécanique minimale, voire aucune perturbation mécanique du sol, l’utilisation des paillis organiques et la diversification des espèces cultivées, associées à d’autres bonnes pratiques de gestion des cultures et de la production, sont aujourd’hui (en 2013) mises en œuvre sur près de 157 millions d’hectares, soit près de 11 % des terres cultivées, sur tous les continents et dans la plupart des écologies agricoles, notamment dans les divers environnements tempérés. Cette évolution représente un écart de près de 47 % au niveau mondial par rapport aux années 2008/09, où l'AC était pratiquée sur 106 millions d’hectares. Le chiffre actuel de 157 millions d’hectares reflète une adoption plus large de l'AC dans un nombre croissant de pays mais il s'agit là d'une estimation prudente, la base de données actualisée ne prenant pas en compte la totalité des terres cultivées en AC. Alors que l'AC couvrait seulement 2,8 M ha dans le monde en 1973/74, elle s'est étendue à 45 M ha en 1999 et 72 M ha en 2003. Au cours des dix dernières années, la surface de terres cultivées en AC s’est développée à un rythme moyen de plus de 8,3 M ha par an et d'environ 10 M ha par an depuis 2008/2009, illustrant l’intérêt croissant des agriculteurs et des gouvernements pour ce concept et ces méthodes de production alternatifs. L'adoption de l'AC a été particulièrement soutenue en Amérique du Nord et en Amérique du Sud, ainsi qu'en Australie et en Asie, et, plus récemment, en Europe et en Afrique, où la sensibilisation aux principes de l'AC et l’encouragement de leur adoption ne cessent d'augmenter. Cet article présente un état des lieux de l'adoption de l'AC depuis 2008/09.Las pruebas empíricas a nivel mundial muestran que la transformación de los sistemas de producción agrícola guiada por los agricultores y basada en los principios de la agricultura de conservación ya se está produciendo y está cobrando impulso en todo el mundo como un nuevo paradigma para el siglo XXI. Los datos presentados en este trabajo han sido obtenidos por la Organización de las Naciones Unidas para la Agricultura y la Alimentación de varias fuentes, entre las que se incluyen las estimaciones realizadas por ministerios de agricultura, organizaciones de agricultores y otros entendidos en la materia de organizaciones de investigación o desarrollo, y proporcionan una perspectiva general de la adopción y la propagación de la agricultura de conservación por país, así como el alcance de la adopción de la agricultura de conservación en los distintos continentes. Los sistemas de agricultura de conservación, que incluyen una perturbación mecánica mínima o nula de la tierra, el uso de una capa de mantillo natural y la diversificación de las especies de cultivo, en combinación con otras prácticas positivas de gestión de cultivos y de la producción, se utilizan actualmente (en 2013) a nivel mundial en unos 157 millones de hectáreas, lo que corresponde aproximadamente al 11 % de las tierras de cultivo, en todos los continentes y la mayoría de las agroecologías basadas en el suelo, incluidos los ambientes templados. Este cambio constituye una diferencia de aproximadamente el 47 % en todo el mundo desde los años 2008-2009 cuando la propagación era de 106 millones de hectáreas. La cifra total actual de 157 millones de hectáreas representa un aumento en la adopción de la agricultura de conservación por parte de más países si bien esta estimación es conservadora ya que la base de datos actualizada no abarca todas las tierras de cultivo en las que se practica la agricultura de conservación. Mientras en los años 1973-1974 los sistemas de agricultura de conservación ocupaban solo 2,8 millones de hectáreas en el mundo, esta extensión fue creciendo hasta alcanzar los 45 millones de hectáreas en 1999 y los 72 millones de hectáreas en 2003. En los últimos 10 años las tierras de cultivo en las que se practica la agricultura de conservación se han extendido a un ritmo medio de más de 8,3 millones de hectáreas por año y desde los años 2008-2009 a un ritmo de unos 10 millones de hectáreas por año, lo que demuestra el creciente interés de los agricultores y los gobiernos nacionales en este concepto y método de producción alternativa. La adopción ha sido especialmente importante en América del Norte y del Sur, así como en Australia y Asia, y más recientemente en Europa y África, donde la concienciación y el apoyo a la agricultura de conservación son cada vez mayores. Este trabajo presenta información actualizada sobre la adopción de la agricultura de conservación desde los años 2008-2009

Success of English Language Learners: Barriers and Strategies

For this report, the researchers sought to gather more information on the success of mainstreamed ELL students from both exited students and their content teachers. The researchers\u27 aim was to see how teachers assessed these students’ academic needs, how these students felt about the accommodations executed by their teachers, and where these mainstreamed students were finding success. Furthermore, researchers wanted to gain information on the perceptions of the teachers working with these students. Information was gathered at two different high schools within the same district by interviewing and surveying both mainstreamed ELLs and their content teachers. Student transcripts were also utilized to gain more information about mainstreamed ELLs’ academic success. Results indicated that some classes, specifically those that required frequent memorization of content, were cited by students as more challenging and were classes in which more students were struggling to demonstrate proficiency, as indicated by their grades. Furthermore, results of teacher surveys and interviews highlighted a lack of comfort in understanding how to communicate with families of these students and how best to meet the academic needs of this population of learners. From these results, researchers drew the need for additional classroom-based and school-wide research. Keywords: ELL, sheltered instruction, mainstream, exite

Spectroscopy of a fractional Josephson vortex molecule

In long Josephson junctions with multiple discontinuities of the Josephson phase, fractional vortex molecules are spontaneously formed. At each discontinuity point a fractional Josephson vortex carrying a magnetic flux $|\Phi|<\Phi_0$, $\Phi_0\approx 2.07\times 10^{-15}$ Wb being the magnetic flux quantum, is pinned. Each vortex has an oscillatory eigenmode with a frequency that depends on $\Phi/\Phi_0$ and lies inside the plasma gap. We experimentally investigate the dependence of the eigenfrequencies of a two-vortex molecule on the distance between the vortices, on their topological charge $\wp=2\pi\Phi/\Phi_0$ and on the bias current $\gamma$ applied to the Josephson junction. We find that with decreasing distance between vortices, a splitting of the eigenfrequencies occurs, that corresponds to the emergence of collective oscillatory modes of both vortices. We use a resonant microwave spectroscopy technique and find good agreement between experimental results and theoretical predictions.Comment: submitted to Phys. Rev.

Generic Model Refactorings

Many modeling languages share some common concepts and principles. For example, Java, MOF, and UML share some aspects of the concepts\ud of classes, methods, attributes, and inheritance. However, model\ud transformations such as refactorings specified for a given language\ud cannot be readily reused for another language because their related\ud metamodels may be structurally different. Our aim is to enable a\ud flexible reuse of model transformations across various metamodels.\ud Thus, in this paper, we present an approach allowing the specification\ud of generic model transformations, in particular refactorings, so\ud that they can be applied to different metamodels. Our approach relies\ud on two mechanisms: (1) an adaptation based mainly on the weaving\ud of aspects; (2) the notion of model typing, an extension of object\ud typing in the model-oriented context. We validated our approach by\ud performing some experiments that consisted of specifying three well\ud known refactorings (Encapsulate Field, Move Method, and Pull Up Method)\ud and applying each of them onto three different metamodels (Java,\ud MOF, and UML)

Thermal escape of fractional vortices in long Josephson junctions

We consider a fractional Josephson vortex in a long 0-kappa Josephson junction. A uniformly applied bias current exerts a Lorentz force on the vortex. If the bias current exceeds the critical current, an integer fluxon is torn off the kappa-vortex and the junction switches to the voltage state. In the presence of thermal fluctuations the escape process takes place with finite probability already at subcritical values of the bias current. We experimentally investigate the thermally induced escape of a fractional vortex by high resolution measurements of the critical current as a function of the topological charge kappa of the vortex and compare the results to numerical simulations for finite junction lengths and to theoretical predictions for infinite junction lengths. To study the effect caused by the junction geometry we compare the vortex escape in annular and linear junctions.Comment: submitted to PR

High Mass Triple Systems: The Classical Cepheid Y Car

We have obtained an HST STIS ultraviolet high dispersion Echelle mode spectrum the binary companion of the double mode classical Cepheid Y Car. The velocity measured for the hot companion from this spectrum is very different from reasonable predictions for binary motion, implying that the companion is itself a short period binary. The measured velocity changed by 7 km/ s during the 4 days between two segments of the observation confirming this interpretation. We summarize "binary" Cepheids which are in fact members of triple system and find at least 44% are triples. The summary of information on Cepheids with orbits makes it likely that the fraction is under-estimated.Comment: accepted by A

Candida spondylodiscitis:a systematic review and meta-analysis of seventy two studies

Objectives: Knowledge of Candida spondylodiscitis is limited to case reports and smaller case series. Controversy remains on the most effective diagnostical and therapeutical steps once Candida is suspected. This systematic review summarized all cases of Candida spondylodiscitis reported to date concerning baseline demographics, symptoms, treatment, and prognostic factors.Methods: A PRISMA-based search of PubMed, Web of Science, Embase, Scopus, and OVID Medline was performed from database inception to November 30, 2022. Reported cases of Candida spondylodiscitis were included regardless of Candida strain or spinal levels involved. Based on these criteria, 656 studies were analyzed and 72 included for analysis. Kaplan-Meier curves, Fisher’s exact, and Wilcoxon’s rank sum tests were performed.Results: In total, 89 patients (67% males) treated for Candida spondylodiscitis were included. Median age was 61 years, 23% were immunocompromised, and 15% IV drug users. Median length of antifungal treatment was six months, and fluconazole (68%) most commonly used. Thirteen percent underwent debridement, 34% discectomy with and 21% without additional instrumentation. Median follow-up was 12 months. The two year survivorship free of death was 80%. The two year survivorship free of revision was 94%. Younger age (p = 0.042) and longer length of antifungal treatment (p = 0.061) were predictive of survival.Conclusion: Most patients affected by Candida spondylodiscitis were males in their sixties, with one in four being immunocompromised. While one in five patients died within two years of diagnosis, younger age and prolonged antifungal treatment might play a protective role.</p

Classical Cepheid Pulsation Models: IX. New Input Physics

We constructed several sequences of classical Cepheid envelope models at solar chemical composition ($Y=0.28, Z=0.02$) to investigate the dependence of the pulsation properties predicted by linear and nonlinear hydrodynamical models on input physics. To study the dependence on the equation of state (EOS) we performed several numerical experiments by using the simplified analytical EOS originally developed by Stellingwerf and the recent analytical EOS developed by Irwin. Current findings suggest that the pulsation amplitudes as well as the topology of the instability strip marginally depend on the adopted EOS. We also investigated the dependence of observables predicted by theoretical models on the mass-luminosity (ML) relation and on the spatial resolution across the Hydrogen and the Helium partial ionization regions. We found that nonlinear models are marginally affected by these physical and numerical assumptions. In particular, the difference between new and old models in the location as well as in the temperature width of the instability strip is on average smaller than 200 K. However, the spatial resolution somehow affects the pulsation properties. The new fine models predict a period at the center of the Hertzsprung Progression ($P_{HP}=9.65$$-$9.84 days) that reasonably agree with empirical data based on light curves ($P_{HP}=10.0\pm 0.5$ days; \citealt{mbm92}) and on radial velocity curves ($P_{HP}=9.95\pm 0.05$ days; \citealt{mall00}), and improve previous predictions by Bono, Castellani, and Marconi (2000, hereinafter BCM00).Comment: 35 pages, 7 figures. Accepted for publication in the Astrophysical Journa

Hydrodynamical Survey of First Overtone Cepheids

A hydrodynamical survey of the pulsational properties of first overtone Galactic Cepheids is presented. The goal of this study is to reproduce their observed light- and radial velocity curves. The comparison between the models and the observations is made in a quantitative manner on the level of the Fourier coefficients. Purely radiative models fail to reproduce the observed features, but convective models give good agreement. It is found that the sharp features in the Fourier coefficients are indeed caused by the P1/P4 = 2 resonance, despite the very large damping of the 4th overtone. For the adopted mass-luminosity relation the resonance center lies near a period of 4.2d +/- 0.2 as indicated by the observed radial velocity data, rather than near 3.2d as the light-curves suggest.Comment: ApJ, 12 pages, (slightly) revise