The Extended Fock Basis of Clifford Algebra

We investigate the properties of the Extended Fock Basis (EFB) of Clifford algebras introduced in [1]. We show that a Clifford algebra can be seen as a direct sum of multiple spinor subspaces that are characterized as being left eigenvectors of \Gamma. We also show that a simple spinor, expressed in Fock basis, can have a maximum number of non zero coordinates that equals the size of the maximal totally null plane (with the notable exception of vectorial spaces with 6 dimensions).Comment: Minimal corrections to the published versio

The Tannakian Formalism and the Langlands Conjectures

Let H be a connected reductive group over an algebraically closed field of characteristic zero, and let G be an abstract group. In this note we show that every homomorphism from the Grothendieck semiring of H to that of G which maps irreducible representations to irreducibles, comes from a group homomorphism from G to H. We also connect this result with the Langlands conjectures.Comment: 15 page

TBFM IDAC Procedure to Disable NASA Connection with CLT STBO Electronic Requests for Release Times

This document defines the procedure to disconnect TBFM IDAC's connection with ATD-2's STBO System at the Washington Air Route Traffic Center. This is part of the ATD-2 ZDC training package that was presented in September 2017

Física cuántica y filosofía.

Sin resume

Complex structures and the Elie Cartan approach to the theory of spinors

Each isometric complex structure on a 2$\ell$-dimensional euclidean space $E$ corresponds to an identification of the Clifford algebra of $E$ with the canonical anticommutation relation algebra for $\ell$ ( fermionic) degrees of freedom. The simple spinors in the terminology of E.~Cartan or the pure spinors in the one of C. Chevalley are the associated vacua. The corresponding states are the Fock states (i.e. pure free states), therefore, none of the above terminologies is very good.Comment: 10

Late Recognized Vascular Injury after High-energy Fracture of the Proximal Tibia: a Pitfall to Know in Current Practice

Failure to recognize associated soft-tissue injuries after high-energy proximal tibia fractures is not uncommon. Despite the progress in managing these complex injuries, a prompt diagnosis of associated arterial injuries still remains difficult. A high index of suspicion for arterial damages is nevertheless mandatory in these severe fractures. Treatment protocols have been developed to reduce the previously reported high rates of amputation and permit an optimal management of soft-tissue and an acceptable functional outcome. We report here a well-documented case of a severely displaced proximal tibia fracture that illustrates the problem of diagnosing and managing the associated vascular injurie

Réinventer la sexualité: Remarques sur les derniers écrits de Michel Foucault

In this paper I wish to comment on the way we conceive of sexual life today, in connection with Michel Foucault’s characterization of “Sex” as something that is part of a “device for sexuality”. The paper is divided into three parts. In the first part, I attempt to analyze and criticize some major components of our conceptions of sex, namely (a) our belief that sex is a private matter, (b) the view that erotism succeeds to be a philosophical clue to the Subject-Object predicament (G. Bataille), and (c) the thesis that a new civilization based on Eros might be born (H. Marcuse). In the second part, I focus on Foucault’s position, which has been widely misunderstood. Foucault’s general argument was that the mechanics of power in our contemporary societies required a well organized device for sexual practice, theory, medical care and so on, since power required close control over the private life of individuals and the disciplinary training of bodies. He opposed the (c) thesis, which he called the “repressive hypothesis”. He also opposed the (b) view, substituting a “genealogy of the man of desire” for Bataille’s conception of erotism. Finally he opposed the (a) belief, by bringing in debate the spectacular counter-example of Ancient Greek and Latin conceptions of sexuality, to the understanding of which he devoted the last years of his life. The third part of this paper then develops Foucault’s basic assumption that in our present time, to resist power will be possible only if we become able to constitute ourselves as individuals in a new way. I argue that the enigma of sex in our lives essentially exhibits our political, philosophical and ethical weakness. With respect to politics we are deprived of the “power to act”, since every confrontation between individuals and the City has become delu- sive, thus making the art of Greek tragedy barely impossible. With respect to philosophy, we meet the major challenge of a new characterization of the Subject. With respect to ethics, we face the reality of violence everywhere. Our “private tragedies” demonstrate that we recoil into private life mainly because we feel that we have lost the world.L’objet de l’article est d’analyser notre conception contemporaine de la sexualité, en liaison avec la caractérisation qu’en proposait Foucault et qui fait du “Sexe” l’élément central d’un “dispositif de sexualité”. Dans la première partie de l’article, je propose d’abord une description critique de certaines des composantes principales de notre conception de la sexualité, qui sont (a) la conviction que le sexe est une affaire privée; (b) l’idée que l’érotisme pourrait être une solution philosophique providentielle à l’opposition du Sujet et de l’Objet (G. Bataille); et (c) la thèse qu’une civilisation nonrépressive est possible (H. Marcuse). Dans la seconde partie je commente les positions de Foucault, qui ont été souvent mal comprises. La thèse générale de Foucault était que les mécanismes du pouvoir, dans les sociétés contemporaines, exigent un contrôle étroit de la vie privée des individus et par là même la mise en oeuvre d’un “dispositif” bien organisé susceptible de régir la pratique sexuelle, de même que sa théorisation et sa médicalisation. Foucault s’opposait à la thèse (c), qu’il appelait “l’hypothèse répressive”. Il s’opposait également à (b), en proposant à la place de l’érotisme de Bataille une “généalogie de l’homme de désir”. Enfin, il s’opposait à la conviction (a) en arguant du spectaculaire contre-exemple des conceptions gréco-latines de la sexualité dans l’Antiquité, auxquelles il avait consacré les dernières années de sa vie. La troisième partie de l’article développe à partir de là la présupposition fondamentale de Foucault selon laquelle la résistance au pouvoir n’est possible à notre époque que si nous parvenons à nous constituir nousmêmes en tant qu’individus d’une manière nouvelle. En accord avec cette présupposition, je propose de dire que l’énigme du sexe dans nos vies exhibe avant tout notre faiblesse politique, philosophique et éthique. En politique nous sommes privés de la “puissance d’agir” parce que toute confrontation effective entre l’individu et la Cité est devenue illusoire, ce qui scelle l’im- possibilité de la tragédie grecque. En philosophie nous rencontrons le défi majeur de savoir comment définir aujourd’hui le concept de Sujet. Du point de vue éthique, nous avons affaire partout à la réalité de la violence. Nos “tragédies privées” démontrent que nous ne nous réfugions dans la vie privée que parce que nous avons le sentiment d’avoir perdu le monde

Prevalence of vertebral fracture in oldest old nursing home residents

Summary: We evaluated vertebral fracture prevalence using DXA-based vertebral fracture assessment and its influence on the Fracture Risk Assessment (FRAX) tool-determined 10-year fracture probability in a cohort of oldest old nursing home residents. More than one third of the subjects had prevalent vertebral fracture and 50% osteoporosis. Probably in relation with the prevailing influence of age and medical history of fracture, adding these information into FRAX did not markedly modify fracture probability. Introduction: Oldest old nursing home residents are at very high risk of fracture. The prevalence of vertebral fracture in this specific population and its influence on fracture probability using the FRAX tool are not known. Methods: Using a mobile DXA osteodensitometer, we studied the prevalence of vertebral fracture, as assessed by vertebral fracture assessment program, of osteoporosis and of sarcopenia in 151 nursing home residents. Ten-year fracture probability was calculated using appropriately calibrated FRAX tool. Results: Vertebral fractures were detected in 36% of oldest old nursing home residents (mean age, 85.9 ± 0.6years). The prevalence of osteoporosis and sarcopenia was 52% and 22%, respectively. Ten-year fracture probability as assessed by FRAX tool was 27% and 15% for major fracture and hip fracture, respectively. Adding BMD or VFA values did not significantly modify it. Conclusion: In oldest old nursing home residents, osteoporosis and vertebral fracture were frequently detected. Ten-year fracture probability appeared to be mainly determined by age and clinical risk factors obtained by medical history, rather than by BMD or vertebral fractur