2,073 research outputs found

    Chemical studies of nutrient requirements of corn and milo

    Get PDF
    Call number: LD2668 .T4 1953 K6Master of Scienc

    Maize Endosperm Tissue Grown In Vitro I. Culture Requirements

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141953/1/ajb214396.pd

    Looking for the order of a system of arbitrary ordinary differential equations. De investigando ordine systematis aequationum differentialium vulgarium cujuscunque

    No full text
    English translation of a posthumous paper in Latin of C.G.J. Jacobi: Journal fĂŒr die reine und angewandte Mathematik, 64 , 4, 297-320, Berlin, Georg Reimer, 1865.International audienceThis paper was edited by S. Cohn and C.W. Borchardt from posthumous manuscripts of C.G.J. Jacobi. The various canonical forms that a given system ordinary differential equations may take are considered. Looking for the order of the system, without using a normal form, is reduced to a problem of inequalities: the affectation problem. A new type of formulas, the truncated determinants, is introduced. The non vanishing of this quantity means that the order will be equal to the value H , solution of this in- equalities problem, which is obtained by an algorithm similar to Harold Kuhn's Hungarian metho

    The reduction to normal form of a non-normal system of differential equations. De aequationum differentialium systemate non normali ad formam normalem revocando

    No full text
    English translation of a posthumous manuscript in Latin first published in Vorlesungen ĂŒber Dynamik von C.G.J. Jacobi nebstes fĂŒnf hinterlassenen Abhandlungen desselben, A. Clesch ed., Berlin, Georg Reimer, 1866.International audienceThis paper was edited by Sigismund Cohn, C.W. Borchardt and A. Clebsch from posthumous manuscripts of C.G.J. Jacobi. The solution of the following problem: "to transform a square table of m^2 numbers by adding minimal numbers l_i to each horizontal row, in such a way that it possess m transversal maxima", determines the order and the shortest normal form reduction of he system: the equations u_i = 0 must be respectively diff erentiated l_i times. One also determines the number of di fferentiations of each equation of the given system needed to produce the differential equations necessary to reduce the proposed system to a single equation

    Systema Emmanuelis Kantii

    Get PDF

    Regional Organisations and International Mediation: The Effectiveness of Insider Mediators

    Get PDF
    During the last two decades of the twentieth century, the world witnessed an increasing number of regional conflict management efforts undertaken by regional inter-governmental organisations. There are therefore strong reasons to study the advantages and disadvantages of mediation efforts by regionalorganisations, and compare these with initiatives taken by the United Nations (UN). In this article, we argue that regional organisations have certain characteristics that in principle make them effective mediators. They are ‘insiders’, closely connected to the conflict at hand, with an intimate knowledge about local conditions, and a stake in the outcome. This article builds on experience from ECOWAS (the Economic Community of West African States) interventions in West Africa to analyse the pros and cons of regional mediation. We find that the interventions did indeed produce beneficial results, but that ECOWAS mediation efforts were disturbed by the fact that its activities were seen as highly partial. We recommend regional mediators to be ‘impartial insiders’, paying special attention to creating relations of trust with all actors involved

    Infrastructure catalogue and criteria for a PBS approach of European heavy commercial vehicles regulation and smart access programme

    Get PDF
    26th PIARC World Road Congress, ABU DHABI, EMIRATS ARABES UNIS, 06-/10/2019 - 10/10/2019In Europe, regulation on weights and dimensions of trucks are prescriptive, rather than performance based, as it is introduced in some other countries (Australia, Canada, South Africa). The performance based standards (PBS) allow more flexibility in the vehicle design and optimize their performances with respect to the infrastructure constraints. Thus, PBS facilitate innovation and industrial progresses, while mitigating adverse effects on infrastructure and road safety. Therefore, the European project FALCON (2016-2018), supported by CEDR proposed a methodology for the development of performance-based criteria and future PBS in Europe. This paper presents the approach developed for bridges and pavements criteria assessment and implementation. For bridges, an exhaustive catalogue of structures has been developed, made of a pool of influence lines representative of the European bridge stock. Then, several design traffic load models used in the EU Member States, including the load models proposed in the Eurocode EN1991-2 Traffic loads on road bridges have been applied and compared on these structures. The governing load models and structures for the current traffic loads have been determined. This enabled proposing a performance-based standard approach, using either a bridge formula or a well-chosen upper limit of the load effects induced by the authorized heavy vehicles. For pavements, a catalogue representing the standard, bituminous and rigid, European pavement structures was developed. The various wears have been reviewed, and design criteria have been listed. The individual impacts of the vehicles of a reference fleet have been calculated, making possible to rank them in terms of aggressiveness for the pavement. That paves the way for a future PBS approach of heavy vehicle type approval, or a revision of the European Directive 2015/719 on commercial vehicles weights and dimensions. It also opens new perspectives to develop a SIAP (Smart Infrastructure Access Programme) to be implemented on the Trans-European road Network, as a tool to enhance the durability of the existing infrastructure with the lowest restrictions on the road freight movements

    Recours à l'apprentissage expérientiel dans la transformation de la pratique médicale de six professionnels dans le contexte de la pandémie du VIH-SIDA

    Get PDF
    La pandĂ©mie qu'a provoquĂ©e le VIH a connu des moments forts ayant affectĂ© les mĂ©decins gais (professionnels) et leurs patients gais ayant contractĂ© le VIH (sujets). Ces moments forts ont dĂ©clenchĂ© chez ces professionnels la rĂ©alisation d'importants apprentissages et transformations. En s'appuyant sur le cadre thĂ©orique de l'apprentissage expĂ©rientiel, cette Ă©tude vise Ă  identifier ces apprentissages et la transformation chez six professionnels lors de moments forts grĂące Ă  leurs sujets, Ă  identifier les processus par lesquels ils ont Ă©tĂ© amenĂ©s Ă  les rĂ©aliser, et Ă  dĂ©couvrir les moteurs qui les ont amenĂ©s Ă  les rĂ©aliser. Une approche qualitative aux visĂ©es interprĂ©tatives a Ă©tĂ© adoptĂ©e afin de circonscrire, du point de vue de six professionnels, leurs apprentissages expĂ©rientiels et la transformation de certains de leurs rapports et de certains de leurs schĂšmes de rĂ©fĂ©rences. La mĂ©thodologie de l'Ă©tude de cas a Ă©tĂ© privilĂ©giĂ©e afin de parvenir Ă  identifier le « quoi », le « comment » et le « pourquoi » (Merriam, 1988) de leurs apprentissages expĂ©rientiels, de la transformation de certains de leurs rapports et de certains de leurs schĂšmes de rĂ©fĂ©rences. L'entretien semi-dirigĂ© a permis de les faire parler de leurs apprentissages et transformations selon des moments forts de leur pratique. Les rĂ©sultats suggĂšrent que les professionnels de l'Ă©tude ont eu recours Ă  des apprentissages surtout informels, par ex. : ils ont appris un nouveau rapport Ă  la maladie elle-mĂȘme et Ă  composer avec le secteur communautaire. Toutefois, ils ont Ă©galement eu recours Ă  des apprentissages plus structurĂ©s, par ex. : ils ont appris lors de rĂ©unions ou rencontres avec les autres professionnels de la clinique afin de discuter de certains dossiers, mais toujours en dehors de la formation mĂ©dicale continue institutionnalisĂ©e. Les apprentissages informels et structurĂ©s leur ont permis d'acquĂ©rir de nouveaux savoirs et de nouvelles façons de se voir, et de voir et de pratiquer la mĂ©decine. Ces apprentissages les ont conduits Ă  transformer, dĂ©velopper et consolider leurs identitĂ©s personnelle et professionnelle, Ă  revoir les rapports avec leurs sujets et Ă  repenser leurs rapports avec les divers rĂ©seaux professionnels et para-professionnels et avec ceux de la sociĂ©tĂ© civile organisĂ©e, sans oublier l'Ă©mergence d'Ă©lĂ©ments de modes alternatifs de dĂ©veloppement professionnel continu. Bien que chaque professionnel n'ait pu ĂȘtre suivi afin d'observer son processus d'apprentissage et de transformation, les rĂ©sultats de l'Ă©tude soutiennent les processus consignĂ©s dans la littĂ©rature thĂ©orique, empirique et autobiographique, bien qu'il s'agisse, dans notre Ă©tude, d'abord de parcours plus complexes, sporadiques et plus longs, et puis de recours complĂ©mentaires Ă  des sources structurĂ©es d'apprentissage sĂ©lectionnĂ©es en consĂ©quence. De plus, les rĂ©sultats suggĂšrent que les professionnels de l'Ă©tude ont beaucoup appris informellement Ă  travers l'expĂ©rience rĂ©flĂ©chie de leurs rapports avec des sujets actifs et informĂ©s. De plus, ces professionnels ont mentionnĂ© que c'Ă©tait l'accumulation de ces annĂ©es et des dissonances cognitives crĂ©Ă©es par la pandĂ©mie qui les avait amenĂ©s Ă  transformer leur façon de se voir, de voir et de pratiquer la mĂ©decine. Dans ce contexte de pandĂ©mie, les moteurs, facteurs ou conditions des apprentissages et des transformations observĂ©es ont Ă©tĂ© nombreux. Il a Ă©tĂ© possible de noter : l'intensitĂ© Ă©motionnelle ressentie par les professionnels, la multiplication des dĂ©couvertes scientifico-mĂ©dicales, la rĂ©alisation que les cas de VIH et de sida ne cessaient d'Ă©voluer, les incertitudes scientifico-mĂ©dicales et professionnelles, la place grandissante de la sexualitĂ© et de l'homosexualitĂ© Ă  l'intĂ©rieur de la conversation professionnel-sujets ainsi que l'accroissement de l'autonomisation des sujets. Cette Ă©tude a contribuĂ© Ă  la fois aux domaines de l'Ă©ducation, de la sexologie et de la mĂ©decine. D'abord, cette Ă©tude a fait avancer l'Ă©tat des connaissances en ce qui concerne l'impact de la prise en charge des sujets, de leurs traitements sur la relation thĂ©rapeutique professionnel-sujets. Elle permet aux professionnels d'accepter davantage la valeur du sujet informateur et formateur, et des apprentissages expĂ©rientiels rĂ©alisĂ©s grĂące Ă  eux, dans la transformation de leur pratique. De plus, elle a apportĂ© un bagage important de faits et de connaissances pouvant ĂȘtre intĂ©grĂ©s Ă  la formation initiale et ultĂ©rieure informelle des professionnels. Du point de vue de la thĂ©orie, cette Ă©tude permettra de constater dans quelle mesure les approches proposĂ©es sont utiles pour comprendre la transformation des savoirs vue sous l'angle professionnel-sujets et d'apporter un regard critique et constructif sur les concepts thĂ©oriques relatifs aux processus d'apprentissage expĂ©rientiel. Mais plus encore, l'apport de cette Ă©tude est intĂ©ressant pour ce qui est de l'approche constructiviste tout en tenant compte du savoir constituĂ© et institutionnalisĂ©, et donc de l'approche cognitive. Finalement, la question est posĂ©e sur les limites du constructiviste de pouvoir Ă©tudier et rendre compte d'un processus socioconstructiviste puisqu'il y a un Ă©lĂ©ment social rattachĂ© aux apprentissages rĂ©alisĂ©s par les professionnels de cette Ă©tude ainsi qu'aux processus d'apprentissage expĂ©rientiel par lesquels ils ont Ă©tĂ© amenĂ©s Ă  effectuer de tels apprentissages. Ils ont Ă©tĂ© rĂ©alisĂ©s via les sujets informateurs et formateurs ainsi que les rĂ©seaux que les professionnels ont su dĂ©velopper, enrichir et maintenir. \ud Cette Ă©tude a Ă©galement gĂ©nĂ©rĂ© de nombreuses hypothĂšses qui ouvrent d'autres avenues de recherche. De mĂȘme, les limites de la recherche ont Ă©tĂ© identifiĂ©es et la façon de les aborder a Ă©tĂ© discutĂ©e. \ud ______________________________________________________________________________ \ud MOTS-CLÉS DE L’AUTEUR : VIH/SIDA, Ă©ducation, mĂ©decine, homosexualitĂ©, apprentissage expĂ©rientiel, Ă©tude de cas

    Gamma-Ray Astrophysics: New Insight Into the Universe

    Get PDF
    During the 15 years that have passed since the first edition of this book was published, there has been a major increase in our knowledge of gamma-ray astronomy. Much of this advance arises from the extensive results that have been forthcoming from the Compton Gamma-Ray Observatory. There has been the discovery of a new class of gamma-ray objects, namely high-energy gamma- ray-emitting blazars, a special class of Active Galactic Nuclei, whose basic high-energy properties now seem to be understood. A much improved picture of our galaxy now exists in the frequency range of gamma rays. The question of whether cosmic rays are galactic or metagalactic now seems settled with certainty. Significant new information exists on the gamma-ray properties of neutron star pulsars, Seyfert galaxies, and gamma-ray bursts. Substantial new insight has been obtained on solar phenomena through gamma-ray observations. Hence, this seemed to be an appropriate time to write a new edition of this book to add the important scientific implications of these many new findings. The special importance of gamma-ray astrophysics had long been recognized by many physicists and astronomers, and theorists had pursued many aspects of the subject well before the experimental results began to become available. The slower development of the experimental side was not because of a lack of incentive, but due to the substantial experimental difficulties that had to be overcome. Thus, as the gamma-ray results became available in much greater number and detail, it was possible to build upon the theoretical work that already existed and to make substantial progress in the study of many of the phenomena involved. Consequently, a much better understanding of many of the astrophysical phenomena mentioned here and others is now possible. Our principal aims in writing this book are the same as they were for the first edition: to provide a text which describes the significance of gamma-ray astrophysics and to assemble in one place a treatment of gamma rays emitted from bodies in the solar i system, from objects in our galaxy, as well as from interactions between cosmic rays and the interstellar medium, and from beyond our galaxy. Thus, this book is intended for those in astrophysics who wish to have the opportunity to learn more about the evolving field of gamma-ray astronomy and its relationship to the high-energy, evolutionary processes occurring in the universe. The last three chapters of the book provide a general discussion of the experimental aspects of the field that seemed best treated together, separately from the astrophysical aspects of gamma-ray astronomy that are discussed in the first ten chapters
    • 

    corecore