Secular variations of magma source compositions in the North Patagonian batholith from the Jurassic to Tertiary: Was mélange melting involved?

This study of Sr-Nd initial isotopic ratios of plutons from the North Patago nian batholith (Argentina and Chile) revealed that a secular evolution spanning 180 m.y., from the Jurassic to Neogene, can be established in terms of magma sources, which in turn are correlated with changes in the tectonic regime. The provenance and composition of end-member components in the source of mag mas are represented by the Sr-Nd initial isotopic ratios (87Sr/86Sr and 143Nd/144Nd) of the plutonic rocks. Our results support the interpretation that source compo sition was determined by incorporation of varied crustal materials and trench sediments via subduction erosion and sediment subduction into a subduction channel mélange. Subsequent melting of subducted mélanges at mantle depths and eventual reaction with the ultramafic mantle are proposed as the main causes of batholith magma generation, which was favored during periods of fast conver gence and high obliquity between the involved plates. We propose that a parental diorite (= andesite) precursor arrived at the lower arc crust, where it underwent fractionation to yield the silicic melts (granodiorites and granites) that formed the batholiths. The diorite precursor could have been in turn fractionated from a more mafic melt of basaltic andesite composition, which was formed within the mantle by complete reaction of the bulk mélanges and the peridotite. Our proposal follows model predictions on the formation of mélange diapirs that carry fertile subducted materials into hot regions of the suprasubduction mantle wedge, where mafic parental magmas of batholiths originate. This model not only accounts for the secular geochemical variations of Andean batholiths, but it also avoids a fundamental paradox of the classical basalt model: the absence of ultramafic cumulates in the lower arc crust and in the continental crust in general

Antibrowning and antimicrobial effects of onion essential oil to preserve the quality of cut potatoes

This study evaluated the effect of onion essential oil (OEO) (0, 0.5, 2.5, and 5 mg ml−1) on microbial growth, browning decay, and sensorial appealing of cut potatoes stored for 15 days at 4 °C. Dipropyl disulphide and dipropyl trisulphide were the main constituents identified in OEO, and its application at a dose of 0.5 mg mlt-1 was the most effective to prevent browning (38.5% inhibition respect to control) during storage, inhibiting PPO activity (39% respect to control) after the treatment. The higher the added OEO concentration the lower microbial growth of the treated product was, achieving a reduction of 1.27 log CFU g−1 for the 5 mg ml−1 treatment. The odour and flavour appealing of cut potatoes were well received by the panelists after 10 days of storage. Therefore, the use of OEO in cut potatoes has a potential as antimicrobial and antibrowning agent

Spectral fluctuation properties of spherical nuclei

The spectral fluctuation properties of spherical nuclei are considered by use of NNSD statistic. With employing a generalized Brody distribution included Poisson, GOE and GUE limits and also MLE technique, the chaoticity parameters are estimated for sequences prepared by all the available empirical data. The ML-based estimated values and also KLD measures propose a non regular dynamic. Also, spherical odd-mass nuclei in the mass region, exhibit a slight deviation to the GUE spectral statistics rather than the GOE.Comment: 10 pages, 2 figure

AXA: a computer program for the management of the Canary Goat Group milking control programs

A computer program, developed in Clipper, for the management of the genealogical and productive information from the Canary Goat Group, is described. The two first sections of this program are planned for the males and females genealogical data arrangement. Third section is devised for the productive data storage. Fourth section is constructed for the emission of reports and finally, fifth section is a miscellaneous of utilities, where the connection with other programs must be highlighted. Also an exit control is enclosed. The basic purposes of this program aim the emission of official production reports for the Administration and farmers, and the information processing for its analysis in programs of genetic selection.Se describe un programa de ordenador, desarrollado en Clipper, para la gestión de la información genealógica y productiva de la Agrupación Caprina Canaria. Sus dos primeras secciones se ocupan de la organización de la información genealógica de machos y de hembras; la tercera de la información productiva; la cuarta de la elaboración de informes y la quinta es una miscelánea de utilidades y un control de salida, con conexión con otros programas. Las misiones básicas del programa se centran en la emisión de informes productivos oficiales, destinados a la administración y a los ganaderos, y la preparación de la información para su análisis en programas de selección genética

Globally-Linked Vortex Clusters in Trapped Wave Fields

We put forward the existence of a rich variety of fully stationary vortex structures, termed H-clusters, made of an increasing number of vortices nested in paraxial wave fields confined by trapping potentials. However, we show that the constituent vortices are globally linked, rather than products of independent vortices. Also, they always feature a monopolar global wave front and exist in nonlinear systems, such as Bose-Einstein condensates. Clusters with multipolar global wave fronts are non-stationary or at best flipping.Comment: 4 pages, 5 PostScript figure

Post-field grinding evaluation of different rail grades in full-scale wheel/rail laboratory tests

Rail grinding is a maintenance task performed in the field to return it to profile and/or remove damage, however, it can affect the surface integrity of the rail. In this paper, the damage resistance of three different ground rails (R260, R350HT and R400HT) was evaluated. Rail samples were ground using the same parameters in a low-traffic line in the field. The rail metallurgy was then examined, and white etching layer (WEL) formation was evaluated. The resistance to wear and rolling contact fatigue (RCF) was studied in a Full-Scale Rig (FSR). Cracking was detected and, in some cases, WEL was found pressed into the pearlitic microstructure whereas in others the bonding between the WEL and the pearlite failed leading to delamination

Planarian regeneration: achievements and future directions after 20 years of research.

Planarians can undergo dramatic changes in body size and regenerate their entire body plan from small pieces after cutting. This remarkable morphological plasticity has made them an excellent model in which to analyze phenomena such as morphogenesis, restoration of pattern and polarity, control of tissue proportions and tissue homeostasis. They have a unique population of pluripotent stem cells in the adult that can give rise to all differentiated cell types, including the germ cells. These cellular characteristics provide an excellent opportunity to study the mechanisms involved in the maintenance and differentiation of cell populations in intact and regenerating animals. Until recently, the planarian model system lacked opportunities for genetic analysis; however, this handicap was overcome in the last decade through the development of new molecular methods which have been successfully applied to planarians. These techniques have allowed analysis of the temporal and spatial expression of genes, as well as interference with gene function, generating the first phenotypes by loss or gain of function. Finally, the sequencing of the planarian genome has provided the essential tools for an in-depth analysis of the genomic regulation of this model system. In this review, we provide an overview of planarians as a model system for research into development and regeneration and describe new lines of investigation in this area

Mixed Methods Use in Project Management Research

Mixed methods research is increasingly being used in business and management disciplines, in spite of positivist traditions. The aim of the study is twofold: (1) to examine the types of mixed methods approaches being used, and (2) to determine the quality of the reporting of mixed methods studies published in the field of project management. A retrospective content analysis of articles from three ranked project management journals was undertaken for a sample period of 2004 to 2010. Our findings suggest the field of project management is in need of capacity building in relation to the good reporting of mixed methods studies