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News Article | April 17, 2017
Site: cerncourier.com

Fluorescence is rare in land animals, being largely limited to parrots and marine turtles. Now, for the first time, it has been found in a frog. Carlos Taboada of CONICET in Buenos Aires and colleagues studied South American polka-dot tree frogs (Hypsiboas punctuatus) collected near Santa Fe in Argentina. The colours of these frogs are normally a combination of muted greens, yellows and reds, but in dim light and UV illumination they glow bright blue and green. This is genuine fluorescence, not the more common bioluminescence in which organisms make their own light. The fluorescent molecules are unlike those in any other animals, being derived from dihydroisoquinoline. In twilight or night-time conditions, the fluorescence contributes 18–29% of the total emerging light, enhancing a creature’s visibility, particularly for amphibians, but the reasons for the fluorescence are still not known.

French National Center for Scientific Research and Conicet | Date: 2017-07-26

The present invention concerns a composition comprising at least three peptides derived from Mycobacterium tuberculosis antigen Rv2626c, its use in the diagnostic of latently infected Mycobacterium tuberculosis (LTBI) subjects, corresponding methods of use and kits.

Conicet, National University of Costa Rica and Plant Bioscience Ltd | Date: 2015-04-30

A polynucleotide having at least 80% sequence identity with the fill-length nucleotide sequence of SEQ ID NO: 1 and substantially identical polynucleotides; an isolated polypeptide having at least 80% sequence identity with the full-length amino acid sequence of SEQ ID NO: 2 and substantially identical polypeptides; and polynucleotides encoding the Ha WRKY76 polypeptide and substantially identical polypeptides are described. Also described are vectors and recombinant expression cassettes containing the c DNA polynucleotide, a polynucleotide encoding the Ha WRKY76 polypeptide, or substantially identical polynucleotides. Transgenic plants containing such expression cassettes, related methods and uses are also provided.

Recently there has been great interest in sparse representations of signals under the assumption that signals (data sets) can be well approximated by a linear combination of few elements of a known basis (dictionary). Many algorithms have been developed to find such representations for one-dimensional signals (vectors), which requires finding the sparsest solution of an underdetermined linear system of algebraic equations. In this letter, we generalize the theory of sparse representations of vectors to multiway arrays (tensors)--signals with a multidimensional structure--by using the Tucker model. Thus, the problem is reduced to solving a large-scale underdetermined linear system of equations possessing a Kronecker structure, for which we have developed a greedy algorithm, Kronecker-OMP, as a generalization of the classical orthogonal matching pursuit (OMP) algorithm for vectors. We also introduce the concept of multiway block-sparse representation of N-way arrays and develop a new greedy algorithm that exploits not only the Kronecker structure but also block sparsity. This allows us to derive a very fast and memory-efficient algorithm called N-BOMP (N-way block OMP). We theoretically demonstrate that under the block-sparsity assumption, our N-BOMP algorithm not only has a considerably lower complexity but is also more precise than the classic OMP algorithm. Moreover, our algorithms can be used for very large-scale problems, which are intractable using standard approaches. We provide several simulations illustrating our results and comparing our algorithms to classical algorithms such as OMP and BP (basis pursuit) algorithms. We also apply the N-BOMP algorithm as a fast solution for the compressed sensing (CS) problem with large-scale data sets, in particular, for 2D compressive imaging (CI) and 3D hyperspectral CI, and we show examples with real-world multidimensional signals.

The auditory system processes time and intensity through separate brainstem pathways to derive spatial location as well as other salient features of sound. The independent coding of time and intensity begins in the cochlea, where afferent neurons can fire action potentials at constant phase throughout a wide range of stimulus intensities. We have investigated time and intensity coding by simultaneous presynaptic and postsynaptic recording at the hair cell-afferent synapse from rats. Trains of depolarizing steps to the hair cell were used to elicit postsynaptic currents that occurred at constant phase for a range of membrane potentials over which release probability varied significantly. To probe the underlying mechanisms, release was examined using single steps to various command voltages. As expected for vesicular release, first synaptic events occurred earlier as presynaptic calcium influx grew larger. However, synaptic depression produced smaller responses with longer first latencies. Thus, during repetitive hair cell stimulation, as the hair cell is more strongly depolarized, increased calcium channel gating hurries transmitter release, but the resulting vesicular depletion produces a compensatory slowing. Quantitative simulation of ribbon function shows that these two factors varied reciprocally with hair cell depolarization (stimulus intensity) to produce constant synaptic phase. Finally, we propose that the observed rapid vesicle replenishment would help maintain the vesicle pool, which in turn would equilibrate with the stimulus intensity (and therefore the number of open Ca 2+ channels), so that for trains of different levels the average phase will be conserved. © 2012 the authors.

Unsain N.,CONICET | Barker P.A.,University of British Columbia
Neuron | Year: 2015

Initially characterized for their roles in apoptosis, executioner caspases have emerged as important regulators of an array of cellular activities. This is especially true in the nervous system, where sublethal caspase activity has been implicated in axonal pathfinding and branching, axonal degeneration, dendrite pruning, regeneration, long-term depression, and metaplasticity. Here we examine the roles of sublethal executioner caspase activity in nervous system development and maintenance, consider the mechanisms that locally activate and restrain these potential killers, and discuss how their activity be subverted in neurodegenerative disease. © 2015 Elsevier Inc.

Agency: European Commission | Branch: H2020 | Program: RIA | Phase: SFS-14a-2014 | Award Amount: 5.35M | Year: 2016

The OLEUM project will generate innovative, more effective and harmonized analytical solutions to detect and fight the most common and emerging frauds and to verify the overall quality of olive oils (OOs). By a core group of 20 partners from 15 countries OLEUM will undertake RESEARCH ACTIVITIES based on the development of IMPROVED and NEW ANALYTICAL METHODS by targeted and omics approaches with the aim: i) to detect new markers of the soft deodorization process; ii) to discover illegal blends between OOs and other vegetable oils; iii) to control OO quality (e.g. freshness); iv) to improve the organoleptic assessment with a Quantitative Panel Test, based on current official methods, and supported by tailored reference materials for better calibration of the sensory panels coupled with rapid screening tools to facilitate the work of the panelists. The most promising OLEUM solutions will be subjected to VALIDATION in conformity with internationally agreed standards by peer laboratories. OLEUM will recreate a realistic deodorization scenario by producing tailored, soft deodorized OOs by lab-scale and up-scaled pilot plants to apply analytical solutions to known samples. Substantial KNOWLEDGE and TECHNOLOGY TRANSFER activities will be envisaged to aid in implementation of: a) a web-based easily-accessible, scalable and constantly updated OLEUM DATABANK, containing all the information from OLEUM research and other reliable international sources, will be available for download data and spectra and to help achieve satisfactory harmonization of analytical approaches among control laboratories; b) the OLEUM NETWORK of relevant OOs stakeholders to maximize the impact of proposed analytical solutions. Finally, a robust dissemination strategy by the OLEUM project aimed at effectively sharing results with all stakeholders in the OO supply chain has the potential to improve consumer and market confidence, and preserve the image of OOs on a global scale.

Ballare C.L.,CONICET
Annual Review of Plant Biology | Year: 2014

Precise allocation of limited resources between growth and defense is critical for plant survival. In shade-intolerant species, perception of competition signals by informational photoreceptors activates shade-avoidance responses and reduces the expression of defenses against pathogens and insects. The main mechanism underlying defense suppression is the simultaneous downregulation of jasmonate and salicylic acid signaling by low ratios of red:far-red radiation. Inactivation of phytochrome B by low red:far-red ratios appears to suppress jasmonate responses by altering the balance between DELLA and JASMONATE ZIM DOMAIN (JAZ) proteins in favor of the latter. Solar UVB radiation is a positive modulator of plant defense, signaling through jasmonate-dependent and jasmonate-independent pathways. Light, perceived by phytochrome B and presumably other photoreceptors, helps plants concentrate their defensive arsenals in photosynthetically valuable leaves. The discovery of connections between photoreceptors and defense signaling is revealing novel mechanisms that control key resource allocation decisions in plant canopies. Copyright © 2014 by Annual Reviews.

Ballare C.L.,CONICET
Trends in Plant Science | Year: 2011

Plants have sophisticated defense systems to protect their tissues against the attack of herbivorous organisms. Many of these defenses are orchestrated by the oxylipin jasmonate. A growing body of evidence indicates that the expression of jasmonate-induced responses is tightly regulated by the ecological context of the plant. Ecological information is provided by molecular signals that indicate the nature of the attacker, the value of the attacked organs, phytochrome status and thereby proximity of competing plants, association with beneficial organisms and history of plant interactions with pathogens and herbivores. This review discusses recent advances in this field and highlights the need to map the activities of informational modulators to specific control points within our emerging model of jasmonate signaling. © 2010 Elsevier Ltd.

Ramirez M.J.,CONICET
Bulletin of the American Museum of Natural History | Year: 2014

A phylogenetic analysis of the two-clawed spiders grouped in Dionycha is presented, with 166 representative species of 49 araneomorph families, scored for 393 characters documented through standardized imaging protocols. The study includes 44 outgroup representatives of the main clades of Araneomorphae, and a revision of the main morphological character systems. Novel terminology is proposed for stereotyped structures on the chelicerae, and the main types of setae and silk spigots are reviewed, summarizing their characteristics. Clear homologs of posterior book lungs are described for early instars of Filistatidae, and a novel type of respiratory structure, the epigastric median tracheae, is described for some terminals probably related with Anyphaenidae or Eutichuridae. A new type of crypsis mechanism is described for a clade of thomisids, which in addition to retaining soil particles, grow fungi on their cuticle. Generalized patterns of cheliceral setae and macrosetae are proposed as synapomorphies of the Divided Cribellum and RTA clades. Dionycha is here proposed as a member of the Oval Calamistrum clade among the lycosoid lineages, and Liocranoides, with three claws and claw tufts, is obtained as a plausible sister group of the dionychan lineage. The morphology of the claw tuft and scopula is examined in detail and scored for 14 characters highly informative for relationships. A kind of seta intermediate between tenent and plumose setae (the pseudotenent type) is found in several spider families, more often reconstructed as a derivation from true tenent setae rather than as a phylogenetic intermediate. Corinnidae is retrieved in a restricted sense, including only the subfamilies Corinninae and Castianeirinae, while the "corinnid" genera retaining the median apophysis in the copulatory bulb are not clearly affiliated to any of the established families. Miturgidae is redefined, including Zoridae as a junior synonym. The Eutichuridae is raised to family status, as well as the Trachelidae and Phrurolithidae. New synapomorphies are provided for Sparassidae, Philodromidae, and Trachelidae. Philodromidae is presented as a plausible sister group of Salticidae, and these sister to Thomisidae; an alternative resolution placing thomisids in Lycosoidea is also examined. The Oblique Median Tapetum (OMT) clade is proposed for a large group of families including gnaphosoids, trachelids, liocranids, and phrurolithids, all having the posterior median eye tapeta forming a 90° angle, used for navigation by means of the polarized light in the sky as an optical compass; prodidomines seem to have further enhanced the mechanism by incorporating the posterior lateral eyes to the system. The Teutamus group is recognized for members of the OMT clade that are usually included in Liocranidae, but not closely related to Liocranum or phrurolithids. The Claw Tuft Clasper (CTC) clade is proposed for a group of families within the OMT clade, all having a peculiar mechanism grasping the folded base of the claw tuft setae with a hook on the superior claws. The CTC clade includes Trachelidae, Phrurolithidae, and several gnaphosoids such as Ammoxenidae, Cithaeronidae, Gnaphosidae, and Prodidomidae. A remarkable syndrome involving the expansion of the anterior lateral spinnerets, often sexually dimorphic, is here reported for some Miturgidae and several members of the CTC clade, in addition to the known cases in Clubionidae and "Liocranidae." The following genera are transferred from Miturgidae to Eutichuridae: Calamoneta, Calamopus, Cheiracanthium, Cheiramiona, Ericaella, Eutichurus, Macerio, Radulphius, Strotarchus, Summacanthium, and Tecution; Lessertina is transferred from Corinnidae to Eutichuridae. The following genera are transferred to Miturgidae: Argoctenus, Elassoctenus, Hestimodema, Hoedillus, Israzorides, Odomasta, Simonus, Thasyraea, Tuxoctenus, Voraptus, Xenoctenus, Zora, and Zoroides, from Zoridae; Odo and Paravulsor, from Ctenidae; Pseudoceto from Corinnidae. The following genera are transferred from Corinnidae to Trachelidae: Afroceto, Cetonana, Fuchiba, Fuchibotulus, Meriola, Metatrachelas, Paccius, Paratrachelas, Patelloceto, Planochelas, Poachelas, Spinotrachelas, Thysanina, Trachelas, Trachelopachys, and Utivarachna. The following genera are transferred from Corinnidae to Phrurolithidae: Abdosetae, Drassinella, Liophrurillus, Plynnon, Orthobula, Otacilia, Phonotimpus, Phrurolinillus, Phrurolithus, Phruronellus, Phrurotimpus, Piabuna, and Scotinella. Dorymetaecus is transferred from Clubionidae to Phrurolithidae. Oedignatha and Koppe are transferred from Corinnidae to Liocranidae. Ciniflella is transferred from Amaurobiidae to Tengellidae. ©2014 American Museum of Natural History.

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