Oscillations of neutral B mesons systems

The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the \bd meson oscillation frequency is \dmd = 0.471 \pm 0.016 \ps and the lower limit on the \bs oscillation frequency is \dms > 12.4 \ps at 95% CL.Comment: 9 page

Customs Unions And Foreign Investment: Theory And Evidence From Mercosur’s Auto Industry

This paper demonstrates how regional trade agreements (RTAs) can lead to both foreign direct investment expansion and relocation effects. These two effects, in return, impact the endogenous formation of RTAs. The investment expansion effect results from foreign firms’ ability to serve a larger market from a single facility. The relocation effect occurs due to the firms’ desire to move their initial plants from high-cost member countries to low-cost ones. The relocation effect can overwhelm the expansion effect for the high-cost members and lead to the collapse of socially efficient RTAs. The auto industry in Mercosur is a great example to study these phenomena. Argentina was worried that low-cost Brazil would attract all of the foreign investment and dominate both markets. To convince Argentina to agree to free trade in automobiles (and to Mercosur), the auto sectoral agreement included the Compensated Trade Clause (CTC) which requires each firm to balance its trade between these countries. This mitigates the relocation problem by forcing firms to produce some models in Argentina and entices the governments to sign the RTA..

Algunas notas sobre arqueología y colonialismo : la zona española del protectorado marroquí, 1912-1945

A lo largo de la primera mitad del siglo XX se desarrollaron en el Norte de Marruecos y en el seno de la administración conjunta hispano-marroquí del Protectorado ejercido por España sobre dichos territorios las estructuras de gestión del Patrimonio Arqueológico de dicha Zona. En los párrafos de este artículo abordaremos el paulatino proceso de construcción de dichas estructuras, que marchó en paralelo al desarrollo de los trabajos de investigación de campo y, en buena medida, de forma subsiguiente a los mismos.Through the several decades belonging to the first half of the XXth Century, the territories of North Marocco, placed under the Spanish Protectorate since the Conference of Algeciras in 1906, experienced the development of real public structures devoted to the management of that area’s Archaeological Heritage. We shall focus on this phenomenon, which is closely related to the development of archaeological research in itself as well

Superconducting cavity transducer for resonant gravitational radiation antennas

Parametric transducers, such as superconducting rf cavities, can boost the bandwidth and sensitivity of the next generation resonant antennas, thanks to a readily available technology. We have developed a fully coupled dynamic model of the system "antenna--transducer" and worked out some estimates of signal--to--noise ratio and the stability conditions in various experimental configurations. We also show the design and the prototype of a rf cavity which, together with a suitable read--out electronic, will be used as a test bench for the parametric transducer.Comment: 7 pages, 3 eps figures. Presented at the 6th Amaldi Conference on Gravitational Waves (2005). Accepted for publication in Journal of Physics: Conference Serie

Acute Stress Eliminates Female Advantage in Detection of Ambiguous Negative Affect

The human stress response evolved to maximize an individual's probability of survival when threatened. The present study addressed whether physical danger modulates perception of an unrelated ambiguous threat and, if so, to what extent this response is sex-specific. The authors utilized a first-time tandem skydive as a stressor, which had been previously validated as producing a highly-controlled, genuinely stressful environment. In a counter-balanced within-subjects design, participants wore a virtual reality helmet to complete an emotion-identification task during the plane's ascent (stress condition) and in the laboratory (control condition). Participants were presented static male faces morphed between 20–80% aggression, which gradually emerged from degraded images. Using a binary forced-choice design, participants identified each ambiguous face as aggressive or neutral. Results showed that participants characterized emotion more rapidly under stress versus control conditions. Unexpectedly, the results also show that while women were more sensitive to affect ambiguity than men under control conditions, they exhibited a marked decrease in sensitivity equivalent to men while under stress

Structure Elucidation of Natural Products From Asteraceae by Modern NMR Techniques and Biomimetic Transformations of 11,13-Dihydroparthenolide.

Chemical analysis of root cultures of Tagetes patula (Asteraceae) provided the knowns 5-acetyl-4-hydroxy-2-isopropenyl-benzofuran, 5-(but-3-en-1-ynyl)-2,2\sp\prime-bithiophene and 5-(4-acetoxy-1 butynyl)-2,2\sp\prime-bithiophene. Their structures were elucidated by spectroscopic methods. Chemical analysis by capillary gas-liquid chromatography-mass spectrocscopy (GC/MS) of Parthenium argentatum (Guayule) provided the known sesquiterpene hydrocarbons 9,10-dihydroguajene, $\alpha$-copaene, alloaromandrene, isolongifolene, germacrene A or $\beta$-elemene and $\alpha$-humulene. The known sesquiterpene esters guayulin A and B and the triterpenes argentatin A and B as well as two new cycloartenol-type triterpenes, 3$\alpha$- and 3$\beta$-hydroargentatin B, were also isolated. The relative configuration, the conformation as well as the \sp1H and \sp{13}C NMR resonance assignments of the two new triterpenes were established by 2D and multipulse NMR techniques. Hydrolysis of guayulin A yielded desacylguayulin A, a stereochemical study of which was performed using modern NMR techniques. Chemical analysis of Baccharis salicina (Asteraceae) yielded the known antitumor flavone centaureidin and two new guaianolides, bacchariolides A and B. Their structures were elucidated by spectroscopic methods. Biomimetic-type reactions of the sesquiterpene lactone 11,13-dihydroparthenolide involved the following transformations: (1) BF\sb3-mediated rearrangement of the germacrolide 4(5)-epoxide to produce a xanthanolide and three cis-guaianolides. (2) m-Chloroperoxybenzoic acid mediated oxidation-rearrangements of a guaianolide 1(10)-ene to produce a xanthanolide, a trans-epoxy-guaianolide, two cis-epoxy-guaianolides and a cyclobutane-type sesquiterpene lactone. (3) BF\sb3-catalyzed rearrangement of a guaianolide 1(10)-$\beta$-epoxide to give a cis-eudesmanolide, a trans-guaianolide, and two cis-guaianolides. The results and proposed mechanisms of these reaction sequences as well as the detailed structure elucidation of the transformation products are described

El Camino de Leloir

originalFil: Parodi, Armando J..3 páginas en papelLFL-CD-OTROS. Escritos de OtrosUnidad documental simpl

Los Trabajos de Leloir

Contiene: I. Trabajos Publicados: listado bibliográfico de la Producción Científica del Dr. Leloir. II. Obra Selecta: análisis realizado por el Dr. Armando J. Parodi con 31 trabajos considerados los más relevantes de Leloir.originalFil: Parodi, Armando J..15 páginas en papelLFL-CD-OTROS. Escritos de OtrosUnidad documental simpl

La Fundación Instituto Leloir -Instituto de Investigaciones Bioquímicas Fundación Campomar (FIL-IIB-FC)- como motor del desarrollo de la investigación en bioquímica en Argentina

El propósito de este escrito es mostrar como tanto del núcleo inicial de investigadores en el Instituto de Investigaciones Bioquímicas Fundación Campomar como de investigadores que se incorporaron posteriormente a él se originaron varios centros de investigación en la misma disciplina en nuestro país.originalFil: Parodi, Armando J.. Fundación Instituto Leloir; Argentina5 páginas en papelLFL-CD-OTROS. Escritos de OtrosUnidad documental simpl