Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by detecting the τ leptons produced in charged current ντ interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the νµ → ντ appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ντ candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of νµ → ντ oscillations in appearance mode with a significance larger than 5 σ.

A recursive algorithm to compute a basis of a similarity

Se definen conceptos y se aplica el teorema de Valverde para escribir un algoritmo que computa bases de similaridades. This paper studies sorne theory and methods to build a representation theorem basis of a similarity from the basis of its subsimilarities, providing an alternative recursive method to compute the basis of a similarity.

First steps in the discovery of patterns in the academic results of telecommunication engineering students in the subjects Analysis of Circuits and Mathematics

In this paper, the results of six years of research in engineering education, in the application of the European Higher Education Area (EHEA) to improve the performance of the students in the subject Analysis of Circuits of Telecommunication Engineering, are analysed taking into consideration the fact that there would be hidden variables that both separate students into subgroups and show the connection among several basic subjects such as Analysis of Circuits (AC) and Mathematics (Math). The discovery of these variables would help us to explain the characteristics of the students through the teaching and learning methodology, and would show that there are some characteristics that instructors do not take into account but that are of paramount importance

Discovery of ferromanganese hydrocarbon-related nodules associated with the Meknes mud volcano (Western Moroccan margin)

A suite of ferromanganese nodules were sampled during the MVSEIS-2008 cruise aboard of the R/V Hespérides in the flanks of Meknes mud volcano (Moroccan margin, NE Central Atlantic). The nodules were collected at water depths between 750-850 m within a seabed area characterized by high acoustic backscatter values. Debris of cold water corals and hydrocarbon-derived authigenic carbonate crusts were sampled at same time. The nodules show tabular morphology, up to 20 cm in maximum diameter and 2 kg of weight, brown-reddish external color and they are internally composed by a concentric to complex arrangement of laminae. The results of X-ray diffraction analysis show that these ferromanganese nodules are essentially composed of goethite and lepidocrocite, being Mn-oxides, silicates (quartz and clay minerals) and carbonates (calcite, dolomite and siderite) accessory to occasional minerals. All the samples display micritic to micro-sparitic mosaic under the petrographic microscope which forms massive, laminated or dendritic-mottled textures. The nodules show a high abundance of Fe, minor Mn and low contents of trace metals and REEs. Mature hydrocarbons, as n-alkanes derived from marine bacterial activity, and phenanthrene have been detected in all the ferromanganese nodules analyzed. These nodules display analogous characteristics (textural, mineralogical and geochemical) to the nodules studied by González et al (2009) in the carbonate mud-mounds in the Gulf of Cadiz, offshore Iberian margin. In this way, the same preliminary genetic model proposed for these nodules might be applicable to those find in the Meknes mud volcano. Therefore, the anaerobic oxidation of hydrocarbon-rich fluids within the mud-breccia sediments in the flanks of Meknes mud volcano would induce the formation of early diagenetic Fe-(Mn) carbonate nodules. Thus, the nodules were later exhumed by the erosive action of sea bottom currents generating the replacement of ferromanganese carbonates by Fe-Mn oxy-hydroxides. Thus, the hydrocarbon-rich fluid venting from deep seated reservoirs and erosive action of bottom currents must have been essential actors, as mineralization controls, for ferromanganese nodules generation and evolution. These findings imply that this type of nodules must be considered as new product as derived from the anaerobic/aerobic oxidation of hydrocarbons in areas of active seepages.

Discovery of a low-mass brown dwarf companion of the young nearby star G196-3.

A substellar-mass object in orbit at about 300 astronomical units from the young low-mass star G 196-3 was detected by direct imaging. Optical and infrared photometry and low- and intermediate-resolution spectroscopy of the faint companion, hereafter referred to as G 196-3B, confirm its cool atmosphere ?15 Jupiter masses. The separation and allow its mass to be estimated at 25?10 between the objects and their mass ratio suggest the fragmentation of a collapsing cloud as the most likely origin for G 196-3B, but alternatively it could have originated from a protoplanetary disc that has been dissipated. Whatever the formation process was, the young age of the primary star (about 100 million years) demonstrates that substellar companions can form on short time scales.

A framework for goal-oriented discovery of resources in the RESTful architecture

One of the challenges facing the current web is the efficient use of all the available information. The Web 2.0 phenomenon has favored the creation of contents by average users, and thus the amount of information that can be found for diverse topics has grown exponentially in the last years. Initiatives such as linked data are helping to build the Semantic Web, in which a set of standards are proposed for the exchange of data among heterogeneous systems. However, these standards are sometimes not used, and there are still plenty of websites that require naive techniques to discover their contents and services. This paper proposes an integrated framework for content and service discovery and extraction. The framework is divided into several layers where the discovery of contents and services is made in a representational stateless transfer system such as the web. It employs several web mining techniques as well as feature-oriented modeling for the discovery of cross-cutting features in web resources. The framework is used in a scenario of electronic newspapers. An intelligent agent crawls the web for related news, and uses services and visits links automatically according to its goal. This scenario illustrates how the discovery is made at different levels and how the use of semantics helps implement an agent that performs high-level tasks.

Phylogenomic analysis of natural products biosynthetic gene clusters allows discovery of arseno-organic metabolites in model streptomycetes

We are indebted with Marnix Medema, Paul Straight and Sean Rovito, for useful discussions and critical reading of the manuscript, as well as with Alicia Chagolla and Yolanda Rodriguez of the MS Service of Unidad Irapuato, Cinvestav, and Araceli Fernandez for technical support in high-performance computing. This work was funded by Conacyt Mexico (grants No. 179290 and 177568) and FINNOVA Mexico (grant No. 214716) to FBG. PCM was funded by Conacyt scholarship (No. 28830) and a Cinvestav posdoctoral fellowship. JF and JFK acknowledge funding from the College of Physical Sciences, University of Aberdeen, UK.

Metabolism of d-Glycero-d-Manno-Heptitol, Volemitol, in Polyanthus. Discovery of a Novel Ketose Reductase1

Volemitol (d-glycero-d-manno-heptitol, α-sedoheptitol) is an unusual seven-carbon sugar alcohol that fulfills several important physiological functions in certain species of the genus Primula. Using the horticultural hybrid polyanthus (Primula × polyantha) as our model plant, we found that volemitol is the major nonstructural carbohydrate in leaves of all stages of development, with concentrations of up to 50 mg/g fresh weight in source leaves (about 25% of the dry weight), followed by sedoheptulose (d-altro-2-heptulose, 36 mg/g fresh weight), and sucrose (4 mg/g fresh weight). Volemitol was shown by the ethylenediaminetetraacetate-exudation technique to be a prominent phloem-mobile carbohydrate. It accounted for about 24% (mol/mol) of the phloem sap carbohydrates, surpassed only by sucrose (63%). Preliminary 14CO2 pulse-chase radiolabeling experiments showed that volemitol was a major photosynthetic product, preceded by the structurally related ketose sedoheptulose. Finally, we present evidence for a novel NADPH-dependent ketose reductase, tentatively called sedoheptulose reductase, in volemitol-containing Primula species, and propose it as responsible for the biosynthesis of volemitol in planta. Using enzyme extracts from polyanthus leaves, we determined that sedoheptulose reductase has a pH optimum between 7.0 and 8.0, a very high substrate specificity, and displays saturable concentration dependence for both sedoheptulose (apparent Km = 21 mm) and NADPH (apparent Km = 0.4 mm). Our results suggest that volemitol is important in certain Primula species as a photosynthetic product, phloem translocate, and storage carbohydrate.

Discovery of genes involved with learning and memory: An experimental synthesis of Hirschian and Benzerian perspectives

The biological bases of learning and memory are being revealed today with a wide array of molecular approaches, most of which entail the analysis of dysfunction produced by gene disruptions. This perspective derives both from early “genetic dissections” of learning in mutant Drosophila by Seymour Benzer and colleagues and from earlier behavior-genetic analyses of learning and in Diptera by Jerry Hirsch and coworkers. Three quantitative-genetic insights derived from these latter studies serve as guiding principles for the former. First, interacting polygenes underlie complex traits. Consequently, learning/memory defects associated with single-gene mutants can be quantified accurately only in equilibrated, heterogeneous genetic backgrounds. Second, complex behavioral responses will be composed of genetically distinct functional components. Thus, genetic dissection of complex traits into specific biobehavioral properties is likely. Finally, disruptions of genes involved with learning/memory are likely to have pleiotropic effects. As a result, task-relevant sensorimotor responses required for normal learning must be assessed carefully to interpret performance in learning/memory experiments. In addition, more specific conclusions will be obtained from reverse-genetic experiments, in which gene disruptions are restricted in time and/or space.

Solution to Darwin's dilemma: Discovery of the missing Precambrian record of life

In 1859, in On the Origin of Species, Darwin broached what he regarded to be the most vexing problem facing his theory of evolution—the lack of a rich fossil record predating the rise of shelly invertebrates that marks the beginning of the Cambrian Period of geologic time (≈550 million years ago), an “inexplicable” absence that could be “truly urged as a valid argument” against his all embracing synthesis. For more than 100 years, the “missing Precambrian history of life” stood out as one of the greatest unsolved mysteries in natural science. But in recent decades, understanding of life's history has changed markedly as the documented fossil record has been extended seven-fold to some 3,500 million years ago, an age more than three-quarters that of the planet itself. This long-sought solution to Darwin's dilemma was set in motion by a small vanguard of workers who blazed the trail in the 1950s and 1960s, just as their course was charted by a few pioneering pathfinders of the previous century, a history of bold pronouncements, dashed dreams, search, and final discovery.

Discovery of a brain promoter from the human transferrin gene and its utilization for development of transgenic mice that express human apolipoprotein E alleles.

Transgenic mice carrying heterologous genes directed by a 670-bp segment of the regulatory sequence from the human transferrin (TF) gene demonstrated high expression in brain. Mice carrying the chimeric 0.67kbTF-CAT gene expressed TF-CAT in neurons and glial cells of the nucleus basalis, the cerebrum, corpus callosum, cerebellum, and hippocampus. In brains from two independent TF-CAT transgenic founder lines, copy number of TF-CAT mRNA exceeded the number of mRNA transcripts encoding either mouse endogenous transferrin or mouse endogenous amyloid precursor protein. In two transgenic founder lines, the chloramphenicol acetyltransferase (CAT) protein synthesized from the TF-CAT mRNA was estimated to be 0.10-0.15% of the total soluble proteins of the brain. High expression observed in brain indicates that the 0.67kbTF promoter is a promising director of brain expression of heterologous genes. Therefore, the promoter has been used to express the three common human apolipoprotein E (apoE) alleles in transgenic mouse brains. The apoE alleles have been implicated in the expression of Alzheimer disease, and the human apoE isoforms are reported to interact with different affinities to the brain beta-amyloid and tau protein in vitro. Results of this study demonstrate high expression and production of human apoE proteins in transgenic mouse brains. The model may be used to characterize the interaction of human apoE isoforms with other brain proteins and provide information helpful in designing therapeutic strategies for Alzheimer disease.

Discovery of adrenomedullin in rat ischemic cortex and evidence for its role in exacerbating focal brain ischemic damage.

Focal brain ischemia is the most common event leading to stroke in humans. To understand the molecular mechanisms associated with brain ischemia, we applied the technique of mRNA differential display and isolated a gene that encodes a recently discovered peptide, adrenomedullin (AM), which is a member of the calcitonin gene-related peptide (CGRP) family. Using the rat focal stroke model of middle cerebral artery occlusion (MCAO), we determined that AM mRNA expression was significantly increased in the ischemic cortex up to 17.4-fold at 3 h post-MCAO (P < 0.05) and 21.7-fold at 6 h post-MCAO (P < 0.05) and remained elevated for up to 15 days (9.6-fold increase; P < 0.05). Immunohistochemical studies localized AM to ischemic neuronal processes, and radioligand (125I-labeled CGRP) displacement revealed high-affinity (IC50 = 80.3 nmol) binding of AM to CGRP receptors in brain cortex. The cerebrovascular function of AM was studied using synthetic AM microinjected onto rat pial vessels using a cranial window or applied to canine basilar arteries in vitro. AM, applied abluminally, produced dose-dependent relaxation of preconstricted pial vessels (P < 0.05). Intracerebroventricular (but not systemic) AM administration at a high dose (8 nmol), prior to and after MCAO, increased the degree of focal ischemic injury (P < 0.05). The ischemia-induced expression of both AM mRNA and peptide in ischemic cortical neurons, the demonstration of the direct vasodilating effects of the peptide on cerebral vessels, and the ability of AM to exacerbate ischemic brain damage suggests that AM plays a significant role in focal ischemic brain injury.

In Vivo screening and discovery of novel candidate thalidomide analogs in the zebrafish embryo and chicken embryo model systems

This study was supported by a Wellcome Trust-NIH PhD Studentship to SB, WDF and NV. Grant number 098252/Z/12/Z. SB, CHC and WDF are supported by the Intramural Research Program, NCI, NIH. NHG and WL are supported by the Intramural Research Program, NIA, NIH.