Light‐Driven gem‐Hydrogenation: An Orthogonal Entry into “Second Generation” Ruthenium Carbene Catalysts for Olefin Metathesis

The newly discovered light‐driven gem‐hydrogenation of alkynes opens an unconventional yet efficient entry into five‐coordinate Grubbs‐type ruthenium carbene complexes with cis‐disposed chloride ligands. Representatives of this class featuring a chelate substructure formed by an iodo‐substituted benzylidene unit react with (substituted) 2‐isopropoxystyrene to give prototypical “second generation” Grubbs‐Hoveyda complexes for olefin metathesis. The new approach to this venerable catalyst family is safe and versatile for it uses a triple bond rather than phenyldiazomethane as the ultimate carbene source and does not require any sacrificial phosphines

Light-Driven Alkyne gem-Hydrogenation: An Intramolecular Approach to Hoveyda–Grubbs Catalysts

The light-driven gem-hydrogenation of internal alkynes in the presence of [(NHC)(η6-cymene)RuCl2] generates discrete ruthenium carbene complexes. When applied to appropriately designed enyne substrates, the reactive intermediates thus formed will engage the tethered olefin in metathetic ring closure while splitting off a Hoveyda–Grubbs-type complex as secondary carbene. This unconventional approach to these classical catalysts for olefin metathesis rivals existing methodology in that it is safe, short, phosphine-free, and uses readily available starting materials

A long-term optical and X-ray ephemeris of the polar EK Ursae Majoris

We searched for long-term period changes in the polar EK UMa using new optical data and archival X-ray/EUV data. An optical ephemeris was derived from data taken remotely with the MONET/N telescope and compared with the X-ray ephemeris based on Einstein, Rosat, and EUVE data. A three-parameter fit to the combined data sets yields the epoch, the period, and the phase offset between the optical minima and the X-ray absorption dips. An added quadratic term is insignificant and sets a limit to the period change. The derived linear ephemeris is valid over 30 years and the common optical and X-ray period is P=0.0795440225(24) days. There is no evidence of long-term O-C variations or a period change over the past 17 years Delta P = -0.14+-0.50 ms. We suggest that the observed period is the orbital period and that the system is tightly synchronized. The limit on Delta P and the phase constancy of the bright part of the light curve indicate that O-C variations of the type seen in the polars DP Leo and HU Aqr or the pre-CV NN Ser do not seem to occur in EK UMa. The X-ray dips lag the optical minima by 9.5+-0.7 deg in azimuth, providing some insight into the accretion geometry.Comment: 4 pages, 2 Postscript figures, accepted for publication in Astronomy & Astrophysic

Treatment with human growth hormone in patients with Prader-Labhart-Willi syndrome reduces body fat and increases muscle mass and physical performance

Twelve children with documented Prader-Labhart-Willi syndrome were treated with human growth hormone (24 U/m2/week) during 1 year. The children were divided into three groups: group 1: overweight and prepubertal (n = 6, age 3.8-7.0 years); group 2: underweight and prepubertal (n = 3, age 0.6-4.1 years); group 3: pubertal (n = 3, age 9.2-14.6 years). In group 1, height increased from -1.7 SD to -0.6 SD, while weight decreased from 1.1 SD to 0.4 SD, with a dramatic drop in weight for height from 3.8 SD to 1.2 SD. Hand length increased from -1.5 SD to -0.4 SD and foot length from -2.5 SD to -1.4 SD. Body fat, measured by dual X-ray energy absorptiometry, dropped by a third, whereas muscle mass increased by a fourth. Physical capability (Wingate test) improved considerably. The children were reported to be much more active and capable. In group 2, similar changes were seen, but weight for height increased, probably because muscle mass increase exceeded fat mass decrease. Changes in group 3 were similar as in group 1, even though far less distinct. Conclusion: Growth hormone treatment in Prader-Labhart-Willi syndrome led to dramatic changes: distinct increase in growth velocity, height and muscle mass, as well as an improvement in physical performance. Fat mass and weight for height decreased in the initially overweight children, and weight for height increased in underweight childre

Preliminary comparison of magmatic manifestations, calc-alkaline affinity and stephanian-permian age, in the Iberian Chain

[Resumen] En este trabajo se estudian, de forma sintética y actualizada, las manifestaciones (hipovolcánicas y volcanoclásticas) calco-alcalinas que, con carácter epizonal, pluriepisódico y edad Stephaniense-Pérmico, afloran en la Cadena Ibérica. El estudio del magmatismo en la cuenca de Sauquillo de Alcázar (Soria) permite identificar la geometría y la modalidad de este magmatismo con mayor precisi6n, respecto a lo obtenido en los cuatro afloramientos volcano-clásticos seleccionados. Los resultados obtenidos facilitan realizar consideraciones sobre el estudio espacio-temporal de este magmatismo..[Abstract] A synthetic and actualized study of several magmatic calc-alkaline manifestations of Stephanian-Permian age, of the Iberian Chain, is proposed in this papero The Sauquillo de Alcázar (Soria) outcrop allows a more complete study (with drilling logs and a surface profile) giving improved spacetime information on the geometry and evolution of this magmatism. Four pyroclastic outcrops are integrated in this compariso

New first trimester crown-rump length's equations optimized by structured data collection from a French general population

--- Objectives --- Prior to foetal karyotyping, the likelihood of Down's syndrome is often determined combining maternal age, serum free beta-HCG, PAPP-A levels and embryonic measurements of crown-rump length and nuchal translucency for gestational ages between 11 and 13 weeks. It appeared important to get a precise knowledge of these scan parameters' normal values during the first trimester. This paper focused on crown-rump length. --- METHODS --- 402 pregnancies from in-vitro fertilization allowing a precise estimation of foetal ages (FA) were used to determine the best model that describes crown-rump length (CRL) as a function of FA. Scan measures by a single operator from 3846 spontaneous pregnancies representative of the general population from Northern France were used to build a mathematical model linking FA and CRL in a context as close as possible to normal scan screening used in Down's syndrome likelihood determination. We modeled both CRL as a function of FA and FA as a function of CRL. For this, we used a clear methodology and performed regressions with heteroskedastic corrections and robust regressions. The results were compared by cross-validation to retain the equations with the best predictive power. We also studied the errors between observed and predicted values. --- Results --- Data from 513 spontaneous pregnancies allowed to model CRL as a function of age of foetal age. The best model was a polynomial of degree 2. Datation with our equation that models spontaneous pregnancies from a general population was in quite agreement with objective datations obtained from 402 IVF pregnancies and thus support the validity of our model. The most precise measure of CRL was when the SD was minimal (1.83mm), for a CRL of 23.6 mm where our model predicted a 49.4 days of foetal age. Our study allowed to model the SD from 30 to 90 days of foetal age and offers the opportunity of using Zscores in the future to detect growth abnormalities. --- Conclusion --- With powerful statistical tools we report a good modeling of the first trimester embryonic growth in the general population allowing a better knowledge of the date of fertilization useful in the ultrasound screening of Down's syndrome. The optimal period to measure CRL and predict foetal age was 49.4 days (9 weeks of gestational age). Our results open the way to the detection of foetal growth abnormalities using CRL Zscores throughout the first trimester

Quantifying ecological variation across jurisdictional boundaries in a management mosaic landscape

Context Large landscapes exhibit natural heterogeneity. Land management can impose additional variation, altering ecosystem patterns. Habitat characteristics may reflect these management factors, potentially resulting in habitat differences that manifest along jurisdictional boundaries. Objectives We characterized the patchwork of habitats across a case study landscape, the Grand Canyon Protected Area-Centered Ecosystem. We asked: how do ecological conditions vary across different types of jurisdictional boundaries on public lands? We hypothesized that differences in fire and grazing, because they respond to differences in management over time, contribute to ecological differences by jurisdiction. Methods We collected plot-scale vegetation and soils data along boundaries between public lands units surrounding the Grand Canyon. We compared locations across boundaries of units managed differently, accounting for vegetation type and elevation differences that pre-date management unit designations. We used generalized mixed effects models to evaluate differences in disturbance and ecology across boundaries. Results Jurisdictions varied in evidence of grazing and fire. After accounting for these differences, some measured vegetation and soil properties also differed among jurisdictions. The greatest differences were between US Forest Service wilderness and Bureau of Land Management units. For most measured variables, US Forest Service non-wilderness units and National Park Service units were intermediate. Conclusions In this study, several ecological properties tracked jurisdictional boundaries, forming a predictable patchwork of habitats. These patterns likely reflect site differences that pre-date jurisdictions as well as those resulting from different management histories. Understanding how ecosystem differences manifest at jurisdictional boundaries can inform resource management, conservation, and cross-boundary collaborations

Bibliografía

Heinz-Rolf Lückert: Konfliktpsychologie. Einfiihrung und Grudlegung. Ernst Reinhardt Verlag. München-Basel 1957, 592 pags / Roberto Zavalloni: La Liberia Personale nel quadro della psicologia della condotta umana. Societa Editrice "Vita e Pensiero". Milano 1956, 310 pags / R. Pauli - W. Arnold: Psychologisches Praktikum, Leitfaden fiir psychologische Ubungen, VI. Wesentlich erweiterte und veranderte Auflage. Gustav Fischer Verlag. Stuttgart 1957, 325 pags. / R. E. Brennan: Historia de la Psicología, según la visión tomista. Prólogo de Jacques Maritain. Versión española de Efren. Villacorta. Revisión y apéndice de Marcos F. Manzanedo. Javier Morata, Editor. Barcelona 1957, 327 pags. / Emilio Mira Y López: Guía de la Salud Mental. Normas practicas de higiene psíquica. Editorial Oberón. Buenos Aires 1957, 164 pags. / Jean Chazal: Etudes de Criminologie Juvenil. Presses Universitaires de France. Paris 1957, 132 pags / Frances Lloyd: Educating the Sub-normal Child. London 1957, Methuen. / Anne Roe: The Psychology of Occupations. John Wiley and amp; Sons, Inc. New York 1956, 340 pags / Stanley S. Marzolf: Psychological Duagnosis and Counseling in the Schools. Henry Holt and amp; Company. New York 1956. 401 pags. / Friedrich Schneider: La educación de sí mismo. Traducción del alemán por Constantino Ruiz Garrido. Editorial Herder. Barcelona 1957, 334 pags. (De venta: Librería Herder, Bogotá). / Anton Wallenstein: La educación del niño y del adolescente. Traducción del alemán por Constantino Ruiz Garrido. Editorial Herder. Barcelona 1957, 4).3 pags. (De venta: Librería Herder, Bogotá). / Gessel, Arnold; Ilg, F. L., y Ames, L. B.: El adolescente de 10 a 16 años. Buenos Aires, Paidos, 1956

Bibliografía

Heinz-Rolf Lückert: Konfliktpsychologie. Einfiihrung und Grudlegung. Ernst Reinhardt Verlag. München-Basel 1957, 592 pags / Roberto Zavalloni: La Liberia Personale nel quadro della psicologia della condotta umana. Societa Editrice "Vita e Pensiero". Milano 1956, 310 pags / R. Pauli - W. Arnold: Psychologisches Praktikum, Leitfaden fiir psychologische Ubungen, VI. Wesentlich erweiterte und veranderte Auflage. Gustav Fischer Verlag. Stuttgart 1957, 325 pags. / R. E. Brennan: Historia de la Psicología, según la visión tomista. Prólogo de Jacques Maritain. Versión española de Efren. Villacorta. Revisión y apéndice de Marcos F. Manzanedo. Javier Morata, Editor. Barcelona 1957, 327 pags. / Emilio Mira Y López: Guía de la Salud Mental. Normas practicas de higiene psíquica. Editorial Oberón. Buenos Aires 1957, 164 pags. / Jean Chazal: Etudes de Criminologie Juvenil. Presses Universitaires de France. Paris 1957, 132 pags / Frances Lloyd: Educating the Sub-normal Child. London 1957, Methuen. / Anne Roe: The Psychology of Occupations. John Wiley and amp; Sons, Inc. New York 1956, 340 pags / Stanley S. Marzolf: Psychological Duagnosis and Counseling in the Schools. Henry Holt and amp; Company. New York 1956. 401 pags. / Friedrich Schneider: La educación de sí mismo. Traducción del alemán por Constantino Ruiz Garrido. Editorial Herder. Barcelona 1957, 334 pags. (De venta: Librería Herder, Bogotá). / Anton Wallenstein: La educación del niño y del adolescente. Traducción del alemán por Constantino Ruiz Garrido. Editorial Herder. Barcelona 1957, 4).3 pags. (De venta: Librería Herder, Bogotá). / Gessel, Arnold; Ilg, F. L., y Ames, L. B.: El adolescente de 10 a 16 años. Buenos Aires, Paidos, 1956