Priority-Driven Differentiated Performance for NoSQL Database-As-a-Service

Designing data stores for native Cloud Computing services brings a number of challenges, especially if the Cloud Provider wants to offer database services capable of controlling the response time for specific customers. These requests may come from heterogeneous data-driven applications with conflicting responsiveness requirements. For instance, a batch processing workload does not require the same level of responsiveness as a time-sensitive one. Their coexistence may interfere with the responsiveness of the time-sensitive workload, such as online video gaming, virtual reality, and cloud-based machine learning. This paper presents a modification to the popular MongoDB NoSQL database to enable differentiated per-user/request performance on a priority basis by leveraging CPU scheduling and synchronization mechanisms available within the Operating System. This is achieved with minimally invasive changes to the source code and without affecting the performance and behavior of the database when the new feature is not in use. The proposed extension has been integrated with the access-control model of MongoDB for secure and controlled access to the new capability. Extensive experimentation with realistic workloads demonstrates how the proposed solution is able to reduce the response times for high-priority users/requests, with respect to lower-priority ones, in scenarios with mixed-priority clients accessing the data store

Genetic control of seed dormancy and pre-harvest sprouting in wheat.

Pre-harvest sprouting (PHS) damage leads to occasional massive losses in all wheat producing areas, causing downgrading of grain quality, that severely limits' end-use applications and results in ;substantial financial losses to farmers and food processors. Red grain color is a traditional marker for,:resistance to sprouting in wheat breeding programs, however red-grained genotype alone does not always guarantee effective resistance. The objective of this work was to find genes for resistance to PHS and investigate its inheritance in Brazilian wheat cultivars. Genetic variation for dormancy was investigated in :the parents, F 1 and 300 F 2 lines derived from the cross Frontana x OR1 and its reciprocal. The germination/ dormancy sprouted grains was evaluated ,on fifty seeds per replication, germinated in paper towel rolls at woC for 5 days. A bimodal distribution for dormancy occurred in the Frontana/OR1 and OR1/Frontana ierived F 2 populations. The mean ratio of dormant and non-dormant seeds of the cross and its reciprocal was 85: 1115, fitting a digeAi~ model of 1: 15 (P < 0.05). In fact, all non after-ripened F 1 seeds germinated. The F2 distribution indicates that two major genes, here calledA,a andB,b, control seed dormancy, which ,It appears to be recessive to dormancy. Only the homozygous aabb is dormant. As expected, there was no . 'effect of maternal tIssues

Ecumenical modal logic

The discussion about how to put together Gentzen's systems for classical and intuitionistic logic in a single unified system is back in fashion. Indeed, recently Prawitz and others have been discussing the so called Ecumenical Systems, where connectives from these logics can co-exist in peace. In Prawitz' system, the classical logician and the intuitionistic logician would share the universal quantifier, conjunction, negation, and the constant for the absurd, but they would each have their own existential quantifier, disjunction, and implication, with different meanings. Prawitz' main idea is that these different meanings are given by a semantical framework that can be accepted by both parties. In a recent work, Ecumenical sequent calculi and a nested system were presented, and some very interesting proof theoretical properties of the systems were established. In this work we extend Prawitz' Ecumenical idea to alethic K-modalities

Efeito do tamanho e da forma da semente na produtividade do milho.

bitstream/item/37495/1/bol-03.pd

Petrogenesis of Cu-Ni sulphide ores from O’okiep and kliprand, Namaqualand, South Africa : constraints from chalcophile metal contents

The petrogenesis of sulphide ores in the O’okiep district has remained controversial. Based mainly on the concentration of chalcophile metals (PGE, Cu, Ni), it is proposed that the sulphides segregated from a basaltic magma generated during melting of sub-continental lithospheric mantle. Sulphide saturation of the magma was delayed due to relatively high fO2 until crustal contamination occurred during the advanced stages of differentiation. The immiscible sulphide melt was entrained and fractionated in dynamic magma conduits. Sulphides enriched in monosulphide solid solution (mss) component precipitated at depth in the Kliprand area of southern Namaqualand to form the Hondekloof deposits, whereas the O’okiep ores crystallised at shallower levels from highly fractionated residual sulphide liquids enriched in intermediate solid solution (iss). Sulphides of intermediate composition occur at Ezelsfontein. In the context of this model, the O’okiep intrusions could represent the proximal magmatic members of an IOCG suite of deposits, raising the prospect for additional IOCG deposits elsewhere in southern Africa. The model also predicts an enhanced potential at O’okiep for undiscovered Ni sulphide ores at depth

A comprehensive study of noble gases and nitrogen in Hypatia, a diamond-rich pebble from SW Egypt

This is a follow-up study of a work by Kramers et al. (2013) on an unusual diamond-rich rock found in the SW side of the Libyan Desert Glass strewn field. This pebble, called Hypatia, is composed of almost pure carbon. Transmission Electron Microscopy and X-ray diffraction results reveal that Hypatia is made of defect-rich diamond containing lonsdaleite and deformation bands. These characteristics are compatible with an impact origin on Earth and/or in space. We analyzed concentrations and isotopic compositions of all five noble gases and nitrogen in several mg sized Hypatia samples. These data confirm that Hypatia is extra-terrestrial. The sample is rich in trapped noble gases with an isotopic composition close to the meteoritic Q component. 40Ar/36Ar ratios in individual steps are as low as 0.4. Concentrations of cosmic-ray produced 21Ne correspond to a nominal cosmic-ray exposure age of ca. 0.1 Myr if produced in a typical m-sized meteoroid. Such an atypically low nominal exposure age suggests high shielding in a considerably larger body. In addition to the Xe-Q composition, an excess of radiogenic 129Xe (from the decay of extinct 129I) is observed (129Xe/132Xe = 1.18 +/- 0.03). Two N components are present, an isotopically heavy component ({\delta}15N = +20 permil) released at low temp. and a major light component ({\delta}15N = -110 permil) at higher temp. This disequilibrium in N suggests that the diamonds in Hypatia were formed in space. Our data are broadly consistent with concentrations and isotopic compositions of noble gases in at least three different types of carbon-rich meteoritic materials. However, Hypatia does not seem to be related to any of these materials, but may have sampled a similar cosmochemical reservoir. Our study does not confirm the presence of exotic noble gases that led Kramers et al. to propose that Hypatia is a remnant of a comet that impacted the Earth

Lista de los peces de la provincia de Santiago del Estero

…los censos de la fauna de un país o región cualquiera, constituyen una suerte de codificación de la Naturaleza, como paso previo e indispensable para un ensayo racional de aprovechamiento de las riquezas naturales y de su adecuada conservación. Desde fines del siglo XVIII se ha dicho, y lo han repetido en nuestro medio, Cosme Argerich, Alberto Palcos y otros estudiosos y cientistas, que un Código de la Naturaleza es indispensable para la libertad de una nación. [R. A. Ringuelet & R. H. Arámburu. Enumeración sistemática de los vertebrados de la Provincia de Buenos Aires. La Plata, MAA, Publ. 119, 1957].Fil: Fernandez, Luis Alfredo. Fundación Miguel Lillo; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nadalin, D.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Lopez, H. L.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Andreoli Bize, M. J.. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; Argentin