Metrics with four conic singularities and spherical quadrilaterals

A spherical quadrilateral is a bordered surface homeomorphic to a closed disk, with four distinguished boundary points called corners, equipped with a Riemannian metric of constant curvature 1, except at the corners, and such that the boundary arcs between the corners are geodesic. We discuss the problem of classification of these quadrilaterals and perform the classification up to isometry in the case that two angles at the corners are multiples of pi. The problem is equivalent to classification of Heun's equations with real parameters and unitary monodromy.Comment: 68 pges, 25 figure

National Space Science Data Center (NSSDC) Data Listing

Satellite and nonsatellite data available from the National Space Science Data Center are listed. The Satellite Data listing includes the spacecraft name, launch date, and an alphabetical list of experiments. The Non-Satellite Data listing contains ground based data, models, computer routines, and composite spacecraft data. The data set name, data form code, quantity of data, and the time space covered are included in the data sets of both listings where appropriate. Geodetic tracking data sets are also included

A Game-Theoretic Approach for Runtime Capacity Allocation in MapReduce

Nowadays many companies have available large amounts of raw, unstructured data. Among Big Data enabling technologies, a central place is held by the MapReduce framework and, in particular, by its open source implementation, Apache Hadoop. For cost effectiveness considerations, a common approach entails sharing server clusters among multiple users. The underlying infrastructure should provide every user with a fair share of computational resources, ensuring that Service Level Agreements (SLAs) are met and avoiding wastes. In this paper we consider two mathematical programming problems that model the optimal allocation of computational resources in a Hadoop 2.x cluster with the aim to develop new capacity allocation techniques that guarantee better performance in shared data centers. Our goal is to get a substantial reduction of power consumption while respecting the deadlines stated in the SLAs and avoiding penalties associated with job rejections. The core of this approach is a distributed algorithm for runtime capacity allocation, based on Game Theory models and techniques, that mimics the MapReduce dynamics by means of interacting players, namely the central Resource Manager and Class Managers

NSSDC data listing

In a highly summarized way, data available from the National Space Science Data Center (NSSDC) is identified. Most data are offline data sets (on magnetic tape or as film/print products of various sizes) from individual instruments carried on spacecraft; these compose the Satellite Data Listing. Descriptive names, time spans, data form, and quantity of these data sets are identified in the listing, which is sorted alphabetically-first by spacecraft name and then by the principal investigator's or team leader's last name. Several data sets held at NSSDC, not associated with individual spaceflight instruments, are identified in separate listings following the Satellite Data Listing. These data sets make up the Supplementary Data Listings and include composite spacecraft data sets, ground-based data, models, and computer routines. The identifiers used in the Supplementary Data Listings were created by NSSDC and are explained in the pages preceding the listings. Data set form codes are listed. NSSDC offers primarily archival, retrieval, replication, and dissemination services associated with the data sets discussed in the two major listings identified above. NSSDC also provides documentation which enables the data recipient to use the data received. NSSDC is working toward expanding presently limited capabilities for data subsetting and for promotion of data files to online residence for user downloading. NSSDC data holdings span the range of scientific disciplines in which NASA is involved, and include astrophysics, lunar and planetary science, solar physics, space plasma physics, and Earth science. In addition to the functions mentioned above, NSSDC offers data via special services and systems in a number of areas, including Astronomical Data Center (ADC), Coordinated Data Analysis Workshops (CDAWs), NASA Climate Data System (NCDS), Pilot Land Data System (PLDS), and Crustal Dynamics Data Information System (CDDIS). Furthermore, NSSDC has a no-password account on its SPAN/Telenet-accessible VAX through which the NASA Master Directory and selected online data bases are accessible and through which any data described here may be ordered. Astrophysics data support by NSSDC is not limited to the ADC. Each of these special services/systems is described briefly

Diagnostic Methodologies of Laser-Initiated 11B(p,α)2α Fusion Reactions

The detection of the ionic products of low-rate fusion reactions, and in particular of the 11B(p,α)2α, is one of the recognized main problems in experiments where these reactions are initiated by tailored interaction of intense and high-energy lasers with matter. A thorough description of this important issue, with a critical comparison of the diagnostic opportunities, is indeed so far. In this work, we describe the common diagnostic methodologies used for the detection of the alpha particles generated by the 11B(p,α)2α reaction and, for each, we outline advantages and limitations, with considerations that can also be applied to other low-rate fusion reactions. We show here that, in general, the univocal characterization of the α products coming from this reaction can be achieved by the simultaneous use of several diagnostic tools placed in close proximity

Synthetic Studies on Gibberellins

A stereospecific synthesis of 3-methoxy-6,16-dioxo-9betaH-gibb-A-triene has been achieved in good yield, starting from a Diels-Alder reaction of itaconic acid with methyl 5-(p-methoxyphenyl)-trans, trans-penta-2,4-dienoate, the major products from which violate the cis addition principle. An efficient stereospecific synthesis of the multifunctional gibberellin synthon 3-methoxy-16,16-ethylenedioxy-9betaH-gibb-A-triene-4,6beta-dicarboxylic acid from 3-methoxy-6,16-dioxo-9betaH-gibb-A-triene is described. Attempted elaboration of 3-methoxy-16,16-ethylenedioxy-9betaH-gibb-A-triene-4,6beta-dicarboxylic acid to methyl 4alpha-carboxyl-10alpha-hydroxy-4beta-methyl-3,16-dioxo-9betaH-gibbane-6beta-carboxylate 4alpha →10alpha lactone, prepared from a mixture of gibberellin A4 and A7 as a relay compound to gibberellin A4, has resulted in this synthesis of methyl 3-methoxy-4-methyl-16,16-ethylenedioxy-9betaH-gibb-A-triene-6beta-carboxylate. A partial solution, by spectroscopic methods, of the problem of assignment of C-9 stereochemistry in gibbanes has been devised

Skeletal Morphology of Opius dissitus and Biosteres carbonarius (Hymenoptera: Braconidae), with a Discussion of Terminology

The Braconidae, a family of parasitic wasps, constitute a major taxonomic challenge with an estimated diversity of 40,000 to 120,000 species worldwide, only 18,000 of which have been described to date. The skeletal morphology of braconids is still not adequately understood and the terminology is partly idiosyncratic, despite the fact that anatomical features form the basis for most taxonomic work on the group. To help address this problem, we describe the external skeletal morphology of Opius dissitus Muesebeck 1963 and Biosteres carbonarius Nees 1834, two diverse representatives of one of the least known and most diverse braconid subfamilies, the Opiinae. We review the terminology used to describe skeletal features in the Ichneumonoidea in general and the Opiinae in particular, and identify a list of recommend terms, which are linked to the online Hymenoptera Anatomy Ontology. The morphology of the studied species is illustrated with SEM-micrographs, photos and line drawings. Based on the examined species, we discuss intraspecific and interspecific morphological variation in the Opiinae and point out character complexes that merit further study

Typo-technological approach of the lithic industry of level 2 of Abric dels Colls (Margalef de Montsant, Priorat, Tarragona)

Aquest treball presenta els resultats de l’estudi tipotecnològic de la indústria lítica de l’estrat 2 de l’Abric dels Colls (Margalef de Montsant, Tarragona). L’objectiu d’aquest estudi és donar a conèixer aquest jaciment, fins ara escassament publicat, i, de manera més concreta, les característiques de la seva indústria lítica. L’estudi ens ha permès concloure que malgrat el seu mòdul més gran, aquesta indústria concorda tecnològicament amb les de la transició Paleolític superior final-Epipaleolític que es situen al XI mil·lenni BP. Així mateix podem apuntar que l’abundància i la qualitat de la matèria primera de la zona esdevenen factors determinants en la seva producció.This paper presents a typo-technological study of the lithic industry corresponding to level 2 of Abric dels Colls site (Margalef de Montsant, Priorat, Tarragona). The purpose of this paper is to present this barely known site, and more specifically to discuss the specificities of the lithic assemblage. We conclude that despite the larger size of the industry recovered at this site, the technology is consistent with the industries characteristic of the Final Upper Palaeolithic-Epipalaeolithic transition, dated on the 11th millennium BP. In addition, it is suggest that both the abundance and quality of raw material in the area become determining factors in the production of this lithic assembly