Facile catalyst separation without water: fluorous biphase hydroformylation of olefins

A novel concept for performing stoichiometric and catalytic chemical transformations has been developed that is based on the limited miscibility of partially or fully fluorinated compounds with nonfluorinated compounds. A fluorous biphase system (FBS) consists of a fluorous phase containing a dissolved reagent or catalyst and another phase, which could be any common organic or nonorganic solvent with limited or no solubility in the fluorous phase. The fluorous phase is defined as the fluorocarbon (mostly perfluorinated alkanes, ethers, and tertiary amines)-rich phase of a biphase system. An FBS compatible reagent or catalyst contains enough fluorous moieties that it will be soluble only or preferentially in the fluorous phase. The most effective fluorous moieties are linear or branched perfluoroalkyl chains with high carbon number; they may also contain heteroatoms. The chemical transformation may occur either in the fluorous phase or at the interface of the two phases. The application of FBS has been demonstrated for the extraction of rhodium from toluene and for the hydroformylation of olefins. The ability to separate a catalyst or a reagent from the products completely at mild conditions could lead to industrial application of homogeneous catalysts or reagents and to the development of more environmentally benign processes.     

Simulating the adsorption of alkanes in zeolites

The configurational-bias Monte Carlo technique is applied to simulate the adsorption of long chain alkanes in zeolites. This simulation technique is several orders of magnitude more efficient than conventional methods that can be used to simulate the adsorption of long chain alkanes. The calculated heats of adsorption are found to be in excellent agreement with experimental data. The results show a surprising chain length dependence of the heats of adsorption. This dependence has a simple molecular explanation in terms of preferential siting of the long chain alkanes.     

Rickets in alpacas (Lama pacos) in New Zealand

Rickets was diagnosed in two weaner alpacas from a flock showing ill thrift and lameness during the winter of 1992. Both animals had abnormally shaped ribs with occasional healing fractures, irregular thickening of growth plates and metaphyseal haemorrhages. The mean serum phosphorus concentrations of the alpacas fell during June and July, even though lambs grazing the same pasture had normal serum phosphorus concentrations and the phosphorus concentration of the pasture was considered adequate. Vitamin D deficiency may also have contributed to the osteodystrophy. The alpacas had a thick fleece during the winter, and diurnal Vitamin D, synthesis resulting from solar irradiation is likely to have been minimal, especially considering the reduced sunshine hours recorded during the 1992 winter. Surviving alpacas recovered after treatment with monosodium phosphate and an oral Vitamin D supplement. It is possible alpacas are more susceptible to deficiencies of phosphorus and Vitamin D than other grazing animals in New Zealand.     

Biochemical polymorphisms in Spanish Avileña-Negra Iberica cattle

SUMMARY: Thirteen biochemical blood polymorphisms were analysed in a population of 149 Spanish Avile?a-Negra Ibérica cattle. The study revealed variation at the following nine loci: HBB, CA, NP, CP, AMY1, ALB, GC, TF and PTF2. The following systems were monomorphic: CAT, DIA1, MDH1 and ME1. Using polyacrylamide-gel electrophoresis, a slow, migrating pair of bands was found in the GC protein system. This pattern is probably controlled by the GC(C) allele, described in only a few cases in cattle. Furthermore, starch-gel electrophoresis allowed the detection of a variant with intermediate mobility between the ALB(A) and the ALB(B) alleles at the albumin locus. A variant with a similar electrophoretic pattern has occasionally been reported in cattle. However, utilizing IEF under denaturing conditions, such a variant could not be differentiated from the ALB(A) allele and thus its significance is not clear. ZUSAMMENFASSUNG: Biochemischer Polymorphismus in spanischen Avile?a-Negra Iberica Rindern Insgesamt 13 biochemische Systeme wurden in einer Population von 149 spanischen Avilena-Negra-Iberika-Rindern hinsichtlich Polymorphismus analysiert. Es zeigten sich Varianten bei folgenden Loci: HBB, CA, NP, CP, AMY1, ANB, GC, TF und BTF2, w?hrend CAT, DEA, MDH1 und ME1 monomorph sind. Bei st?rke Gel-Elektrophorese wurde im Albumin-Locus eine Variante mit intermedi?rer Mobilit?t zwischen ALB(A) und ?LB(B) Allel entdeckt. Eine solche Variante wurde bisher nur sehr selten bei Rindern beobachtet. Darüber hinaus wurde bei Polyacrylamid-Gel-Elektrophorese ein langsam wanderndes Paar von B?ndern im GC-Proteinsystem gefunden. Dieses Muster ist wahrscheinlich von dem selten vorkommenden GC(C) -Allel verursacht. RESUMEN: Se analizaron trece polimorfismos bioquímicos sanguíneos en una población de 149 animales de la raza Avile?a-Negra Ibérica de ganado vacuno. El estudio reveló la existencia de variación en los nueve loci siguientes: HBB, CA, NP, CP, AMY1, ALB, GC, TF y PTF2. Fueron monomórficos los sistemas siguientes: CAT, DIA1, MDH1 y ME1. Utilizando eletroforesis en gel de poliacrilamida se encontró un par de bandas de migración lenta en el sistema de la proteína GC. Este patrón probablemente está controlado por el infrecuente alelo GC(C) , descrito en unos pocos casos en el ganado vacuno. Además, la electroforesis en gel de almidón permitió detectar en el locus de la albúmina una banda con movilidad intermedia entre los alelos ALB(A) y ALB(B) . Una variante con un patrón electroforético similar ha sido descrita en muy pocas ocasiones en el ganado vacuno. Sin embargo, la utilización de IEF en condiciones desnaturalizantes no permitió diferenciar esta variante del alelo ALB(A) y, por lo tanto, el significado de la misma no está claro.     

Additive genetic and maternal effects on postweaning growth and carcass traits in rabbits

SUMMARY: Additive genetic and maternal effects were estimated for postweaning growth traits and carcass traits using a derivate-free REML procedure under animal model. The traits studied were weight at 84 days of age, age at slaughter, postweaning ADG, dressing percentage, weight of kidney and pelvic fat, and muscle pH value and electrical conductivity in the semimembranosus muscle. Heritability estimates from a total of 728 rabbits in a reciprocal crossbreeding experiment ranged from 0.15 to 0.26 for postweaning growth traits, 0.21 for dressing percentage, 0.38 for weight of kidney and pelvic fat, 0.02 for pH value, and 0.51 for electrical conductivity. Considerable maternal effects were present in postweaning growth traits and in weight of kidney and pelvic fat. Genetic correlation estimates indicated that genetic selection for postweaning daily gain would lead to lower dressing percentages (- 0.51) and leaner carcasses (- 0.34). The genetic relationships between ADG after weaning and pH value (- 0.90), and between ADG and electrical conductivity (0.58) illustrated a shifting towards a glycolytic energy metabolism of the muscle due to increased growth. Litter size at birth was found to be a significant source of variation for all postweaning growth traits (p < 0.001) and for electrical conductivity (p < 0.05). Genetic selection for litter size at birth would result in decreased growth rates, lower dressing percentage and enhanced adiposis. ZUSAMMENFASSUNG: Die Sch?tzung additiv-genetischer und maternaler Effekte auf Mastleistungs- und Schlachtk?rpermerkmale beim Kaninchen Additiv-genetische und maternale Effekte wurden für Mastleistungsmerkmale nach dem Absetzen und für Schlachtk?rpermerkmale anhand eines Tiermodells (DFREML-Methode) gesch?tzt. Bei den untersuchten Merkmalen handelt es sich um das 84-Tage-Gewicht, das Schlachtalter, Zunahmen nach dem Absetzen, Ausschlachtungsprozente, Nieren- und Beckenfettgewicht und um den pH-Wert und die elektrische Leitf?higkeit im M. semimembranosus. Die Heritabilit?tssch?tzungen an insgesamt 728 Tieren, die aus einem reziproken Kreuzungsversuch stammten, lagen bei den Wachstumsmerkmalen zwischen h(2) = 0,15 und h(2) = 0,26. Sie betrugen h(2) = 0,21 für die Ausschlachtungsprozente, h(2) = 0,38 für das Nieren- und Beckenfettgewicht, h(2) = 0,02 für den pH-Wert und h(2) = 0,51 für die Leitf?higkeitsmessung. Die Sch?tzung genetischer Korrelationen deutet an, da? eine genetische Selektion auf t?gliche Zunahmen nach dem Absetzen zu einer verringerten Ausschlachtung (- 0,51) und zu magereren Schlachtk?rpern führen würde. Die genetischen Beziehungen zwischen den Zunahmen und dem pH-Wert (- 0,90) und zwischen den Zunahmen und der elektrischen Leitf?higkeit (0,58) lassen eine Verschiebung in Richtung eines glykolytischen Muskelenergiestoffwechsels bei verst?rktem Wachstum erwarten. Die Wurfgr??e bei der Geburt stellt eine signifikante Variationsursache für die Mastleistungsmerkmale nach dem Absetzen (p < 0,001) una für die elektrische Leitf?higkeit (p < 0,05) dar. Bei einer Erh?hung der Wurfgr??e durch Selektion sind verminderte Wachstumsraten, geringere Ausschlachtungsprozente und verst?rkte Verfettung zu befürchten.     

Correct equations for comparing models in diallel analysis

SUMMARY: Correct equations are given to express the parameter estimates of four models for complete diallels as a function of the parameter estimates in the model of Eisen et al. (1983). In recent literature these equations have been partly incorrect. ZUSAMMENFASSUNG: Korrekte Gleichungen für den Vergleich von Modellen in der Diallelanalyse Für die Darstellung der Parametersch?tzwerte von vier Modellen für vollst?ndige Diallele als Funktion der Parametersch?tzwerte des Modells von Eisen et al. (1983), die in der Literatur teilweise fehlerhaft erfolgte, werden korrekte Formeln angegeben.