The versatility and utilization of phosphorus based compounds in classic carbon-carbon bond forming and esterification reactions

The phosphonium salt room temperature ionic liquid tetradecyltrihexylphosphonium chloride (THPC) has been employed as an efficient reusable media for the palladium catalyzed Suzuki cross-coupling reaction of aryl halides, including aryl chlorides, under mild conditions. The cross-coupling reactions were found to proceed in THPC containing small amounts ofwater and toluene (single phase) using potassium phosphate and 1% Pd2(dba)3'CHCI3. Variously substituted iodobenzenes, including electron rich derivatives, reacted efficiently in THPC with a variety of arylboronic acids and were all complete within 1 hour at 50°C. The corresponding aryl bromides also reacted under these conditions with the addition of a catalytic amount of triphenylphosphine that allowed for complete conversion and high isolated yields. The reactions involving aryl chlorides were considerably slower, although the addition of triphenylphosphine and heating at 70°C allowed high conversion of electron deficient derivatives. Addition of water and hexane to the reaction products results in a triphasic system, from which the catalyst was then recycled by removing the top (hexanes) and bottom (aqueous) layers and adding the reagents to the ionic liquid which was heated again at 50°C; resulting in complete turnover of iodobenzene. Repetition of this procedure gave the biphenyl product in 82-97% yield (repeated five times) for both the initial and recycled reaction sequences. IL ESTERIFICATIONREACTION A new class oftrialkylphosphorane has been prepared through reaction of a trialkylphosphine with 2-chlorodimethylmalonate in the presence oftriethylamine. These new reagents promote the condensation reaction of carboxylic acids with alcohols to provide esters along with trialkylphosphine oxide and dimethylmalonate. The condensation reaction of chiral secondary alcohols can be controlled to give either high levels of inversion or retention through a subtle interplay involving basicity of the reaction media, solvent, and tuning the electronic and steric nature of the carboxylic acid and stenc nature of the phosphorane employed. A coherent mechanism is postulated to explain these observations involving reaction via an initial acyloxyphosphonium ion.

The classic french reader, for advanced students: or, beauties of the french writers, ancient and modern

UANL

The career of the missed encounter in classic american literature

Cette dissertation explore la carrière de la rencontre manquée Lacanienne dans la littérature canonique américaine du dix-neuvième siècle à travers le prisme de la psychanalyse, la déconstruction, le postmodernisme et le postcolonialisme. Je me concentre particulièrement sur La Lettre Écarlate de Hawthorne et Moby-Dick de Melville, en montrant comment ils sont investis dans l'économie narrative de la rencontre manquée, l'économie de ce qui est au-delà de la symbolisation et l'assimilation. L’introduction examine les contours et les détours historiques, philosophiques et théoriques du concept de la rencontre manquée. Cette dissertation a donc deux objectifs: d'une part, elle tente d'examiner le statut et la fonction de la rencontre manquée dans la littérature américaine du dix-neuvième siècle, et d’autre part, elle explore comment la théorisation de la rencontre manquée pourrait nous aider à aller au-delà de la théorisation binaire qui caractérise les scènes géopolitiques actuelles. Mon premier chapitre sur La Lettre Écarlate de Hawthorne, tente de tracer la carrière du signifiant comme une navette entre l'archive et l'avenir, entre le sujet et l'objet, entre le signifiant et le signifié. Le but de ce chapitre est de rendre compte de la temporalité du signifiant et la temporalité de la subjectivité et d’expliquer comment ils répondent à la temporalité du tuché. En explorant la dimension crypto-temporelle de la rencontre manquée, ce chapitre étudie l'excès de cryptes par la poétique (principalement prosopopée, anasémie, et les tropes d'exhumation). Le deuxième chapitre élabore sur les contours de la rencontre manquée. En adoptant des approches psychanalytiques et déconstructives, ce chapitre négocie la temporalité de la rencontre manquée (la temporalité de l'automaton et de la répétition). En explorant la temporalité narrative (prolepse et analepse) conjointement à la psycho-poétique du double, ce chapitre essaie de dévoiler les vicissitudes de la mélancolie et la “dépression narcissique” dans Moby-Dick (en particulier la répétition d'Achab lors de sa rencontre originelle dénarrée ou jamais racontée avec le cachalot blanc et sa position mélancolique par rapport à l'objet qu'il a perdu). En exposant la nature du trauma comme une rencontre manquée, dont les résidus se manifestent symptomatiquement par la répétition (et le doublement), ce chapitre explique le glissement de la lettre (par l'entremise du supplément et de la différance). Le troisième chapitre élargit la portée de la rencontre manquée pour inclure les Autres de l'Amérique. Le but principal de ce chapitre est d'évaluer les investitures politiques, culturelles, imaginaires et libidinales de la rencontre manquée dans le Réel, le Symbolique nationale des États-Unis et la réalité géopolitique actuelle. Il traite également de la relation ambiguë entre la jouissance et le Symbolique: la manière dont la jouissance anime et régit le Symbolique tout en confondant la distinction entre le Réel et la réalité et en protégeant ses manœuvres excessives.

The Snail Darter, The Tellico Dam, and Sustainable Democracy — Lessons for the Next President From a Classic Environmental Law Controversy.

This presentation was the product of an invitation to speak at a symposium for students and faculty from a variety of different non-law departments at the University of Tennessee, where in 1973 I had started what became a six-year legal campaign to divert the Tennessee Valley Authority from impounding the last flowing 33 miles of the Little Tennessee River behind TVA’s Tellico Dam.

Laser Safety in higher education - Classic video!

Vintage video (1986) on laser safety, presented by Dr. Gillian Rice. This is a 37 minute video, explaining the hazards which are likely to be encountered and ways to reduce those hazards in teaching and research laboratories in higher education. Presented in 5 parts: Part 1 (1:49) Laser radiation and the body Part 2 (8:49) Classes of laser Part 3 (13:32) Safety measures Part 4 (21:32) Other risks: precautions Part 5 (31:49) Summary

Beginning to read : the new phonics in context : a precis of the classic text.

Trata de conciliar el debate que ha dividido durante décadas a los teóricos sobre el 'correcto' modo de ayudar a los niños a aprender a leer, y pone de manifiesto que los educadores no deben verse atrapados en el dilema de fonética versus lectura con significado. Se propone un tratamiento integral, incluida la fonética, de los conocimientos y los procesos involucrados en el desarrollo de la habilidad para la lectura.

The adult learner : the definitive classic in adult education and human resource development.

Es una lectura esencial para los profesionales del aprendizaje de adultos, estudiantes y profesionales de los recursos humanos, pues proporciona un marco teórico para la comprensión de los problemas del aprendizaje de adultos, tanto en los entornos docentes como en los lugares de trabajo. Se divide en tres partes: la primera parte estudia 'Las raíces de la andragogía', se traza el desarrollo de esta teoría y las características de los estudiantes adultos; en la segunda parte 'Los avances en el aprendizaje de adultos', se explican sus perspectivas de futuro en la investigación y la práctica y, en la última parte, 'Practica en el aprendizaje de adultos', se presentan lecturas seleccionadas que desarrollan los aspectos específicos de la andragogía en la práctica y que incluye estrategias para implementar los supuestos básicos, para adaptar el aprendizaje a las diferencias individuales, y para implementar la educación de adultos en las organizaciones. De especial interés son dos instrumentos de autoevaluación, 'the Core Competency Diagnostic and Planning Guide' y 'the Personal Adult Learning Style Inventory' que permiten al lector ponerse en camino del desarrollo personal en el aprendizaje de adultos.

Originals : classic and modern fiction and non-fiction in English with key.

Libro para estudiantes de inglés como lengua extranjera de nivel intermedio que quieran mejorar mediante la lectura, y para la preparación del examen Cambridge Preliminary English Test (PET). Contiene 28 fragmentos de obras clásicas y modernas de ficción o basadas en hechos reales, escritas en inglés por autores de distintos países, en orden ascendente de dificultad. Incluye una breve biografía de cada autor, preguntas previas a la lectura para estimular el interés, ejercicios de compresión y debate para trabajar con el texto, y ejercicios de vocabulario y gramática. Hay una sección con todas las soluciones al final del libro.

The classic stories

Se describe una experiencia llevada a cabo en la CEPA de Miajadas (C??ceres), que consisti?? en dramatizar algunos cuentos cl??sicos en ingl??s en centros educativos de la zona. La actividad conllev?? la lectura de los textos, su memorizaci??n, la adaptaci??n del vocabulario al p??blico y por ??ltimo, la dramatizaci??n

Rapid radiation in spiny lobsters (Palinurus spp) as revealed by classic and ABC methods using mtDNA and microsatellite data

Background: Molecular tools may help to uncover closely related and still diverging species from a wide variety of taxa and provide insight into the mechanisms, pace and geography of marine speciation. There is a certain controversy on the phylogeography and speciation modes of species-groups with an Eastern Atlantic-Western Indian Ocean distribution, with previous studies suggesting that older events (Miocene) and/or more recent (Pleistocene) oceanographic processes could have influenced the phylogeny of marine taxa. The spiny lobster genus Palinurus allows for testing among speciation hypotheses, since it has a particular distribution with two groups of three species each in the Northeastern Atlantic (P. elephas, P. mauritanicus and P. charlestoni) and Southeastern Atlantic and Southwestern Indian Oceans (P. gilchristi, P. delagoae and P. barbarae). In the present study, we obtain a more complete understanding of the phylogenetic relationships among these species through a combined dataset with both nuclear and mitochondrial markers, by testing alternative hypotheses on both the mutation rate and tree topology under the recently developed approximate Bayesian computation (ABC) methods. Results: Our analyses support a North-to-South speciation pattern in Palinurus with all the South-African species forming a monophyletic clade nested within the Northern Hemisphere species. Coalescent-based ABC methods allowed us to reject the previously proposed hypothesis of a Middle Miocene speciation event related with the closure of the Tethyan Seaway. Instead, divergence times obtained for Palinurus species using the combined mtDNA-microsatellite dataset and standard mutation rates for mtDNA agree with known glaciation-related processes occurring during the last 2 my. Conclusion: The Palinurus speciation pattern is a typical example of a series of rapid speciation events occurring within a group, with very short branches separating different species. Our results support the hypothesis that recent climate change-related oceanographic processes have influenced the phylogeny of marine taxa, with most Palinurus species originating during the last two million years. The present study highlights the value of new coalescent-based statistical methods such as ABC for testing different speciation hypotheses using molecular data.

Selective biodegradation of keratin matrix in feather rachis reveals classic bioengineering

Flight necessitates that the feather rachis is extremely tough and light. Yet, the crucial filamentous hierarchy of the rachis is unknown—study hindered by the tight chemical bonding between the filaments and matrix. We used novel microbial biodegradation to delineate the fibres of the rachidial cortex in situ. It revealed the thickest keratin filaments known to date (factor >10), approximately 6 µm thick, extending predominantly axially but with a small outer circumferential component. Near-periodic thickened nodes of the fibres are staggered with those in adjacent fibres in two- and three-dimensional planes, creating a fibre–matrix texture with high attributes for crack stopping and resistance to transverse cutting. Close association of the fibre layer with the underlying ‘spongy’ medulloid pith indicates the potential for higher buckling loads and greater elastic recoil. Strikingly, the fibres are similar in dimensions and form to the free filaments of the feather vane and plumulaceous and embryonic down, the syncitial barbules, but, identified for the first time in 140+ years of study in a new location—as a major structural component of the rachis. Early in feather evolution, syncitial barbules were consolidated in a robust central rachis, definitively characterizing the avian lineage of keratin.

Classic and molecular study of Giardia duodenalis in children from a daycare center in the region of Presidente Prudente, São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)