525 research outputs found

    Los peces (Chondrichthyes, Osteichthyes) del Plioceno inferior de Gran Canaria y Fuerteventura (Islas Canarias, España)

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    Fossil fish teeth are contained in marine deposits dated at ca 4.8 Ma found on the islands of Gran Canaria and Fuerteventura (Canary Islands, Spain). These islands, situated in the North Atlantic Subtropical Gyre, can be considered a mid-way stopover point between the Caribbean Sea, with the Central American Seaway about to close in this epoch, and the Mediterranean, in the first stage of its post-Messinian Gibraltar Seaway period. Accordingly, there existed extensive pantropical communication, particularly for nektonic animals capable of travelling large distances. In this paper, we present a number of fossil fishes, most of which are identified for the first time on the basis of their teeth: the Chondrichthyes species Carcharocles megalodon, Parotodus benedeni, Cosmopolitodus hastalis, Isurus oxyrinchus, Carcharias cf. acutissima, Carcharhinus cf. leucas, Carcharhinus cf. priscus, Galeocerdo cf. aduncus, and the Osteichthyes species Archosargus cinctus, Labrodon pavimentatum, and Diodon scillae. Coincidences are observed between these ichthyofauna and specimens found in the Azores Islands, the Pacific coast of America and the Mediterranean Sea.Los dientes fósiles de peces están contenidos en depósitos marinos datados en ca 4.8 Ma de las Islas de Gran Canaria y Fuerteventura (Islas Canarias, España). Estas islas, situadas en el Giro subtropical del Atlántico Norte, pueden considerarse una estación intermedia entre un Mar Caribe que estaba cercano al cierre del Paso de América Central, y el Mediterráneo en su primera etapa tras la apertura post-Mesiniense de Gibraltar. Ello permitía una comunicación pantropical para los animales del necton que eran capaces de desplazarse a grandes distancias. Se identifican por primera vez los peces Chondrichthyes Carcharocles megalodon, Parotodus benedeni, Cosmopolitodus hastalis, Isurus oxyrinchus, Carcharias cf. acutissima, Carcharhinus cf. leucas, Carcharhinus cf. priscus, Galeocerdo cf. aduncus y las species de Osteichthyes Archosargus cinctus, Labrodon pavimentatum y Diodon scillae. Se ha observado coincidencia entre los ejemplares canarios y los encontrados en las Islas Azores, las costas pacíficas de América y el mar Mediterráneo

    Los fósiles del Pleistoceno marino de Las Palmas (Gran Canaria) y de La Guirra (Fuerteventura)

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    Obras de construcción en San Cristóbal (Las Palmas de Gran Canaria) han proporcionado una nueva sección de los depósitos marines pleistocenos que se extienden bajo la ciudad a lo largo de una decena de km. El contenido fosilífero en especies senegalesas permite relacionarlos con el máximo de temperaturas alcanzado durante el último interglacial (MIS 5.5). Con la misma fauna el yacimiento de La Guirra en Fuerteventura, de singular interés por conservar intacto el máximo transgresivo, permite contrastar las alturas máximas (+ 12 m y +8 m asl respectivamente) en ambas islas. Cifras notablemente diferentes a lo publicado. Un centenar de especies han sido catalogadas y más de una veintena son citas nuevas. Los fósiles de carácter ecuatorial contenidos en los depósitos marinos de La Guirra, sobre un paleosuelo y bajo una costra calcárea, permiten la reconstrucción paleoclimática del último interglacial que se inicia con un periodo húmedo y cálido al que le sigue el máximo térmico y finaliza con un periodo árido y cálido.Obres de construcció a San Cristóbal (Las Palmas de Gran Canària) han proporcionat una nova secció dels dipósits marins pleistocens que s'estenien sota la ciutat al llarg d'una desena de quilòmetres. El contingut fossilífer en espècies senegaleses permet relacionar-los amb el màxim de temperatures aconseguit durant l'últim interglacial (MIS 5.5). Amb la mateixa fauna del jaciment de Las Palmas, el jaciment de La Guirra a Fuerteventura, de singular interès per conservar intacte el màxim transgressiu, permet contrastar les altures màximes on es troben els dipòsits a l'actualitat (+12 m i +8 m respectivament) a ambdues illes. Xifres notablement diferents a lo publicat. Un centenar d'espècies han estat observades pels autors i una vintena són cites noves. Els fòssils de caràcter equatorial continguts als dipòsits marins de La Guirra, sobre un paleosòl i sota una crosta calcària permeten la reconstrucció paleoclimàtica de I 'últim interglacial iniciada amb un període humit i càlid, seguida del màxim tèrmic i finalitzada amb un període càlid

    Requirement for pectin methyl esterase and preference for fragmented over native pectins for wall-associated kinase-activated, EDS1/PAD4-dependent stress response in arabidopsis

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    Background: The wall-associated kinases (WAKs) serve as pectin receptors. Results: A pectin methyl esterase and two transcription factor mutants suppress a dominant WAK allele. Conclusion: De-esterification of pectin is required for WAK activation though EDS1 and PAD4. Significance: The results provide a mechanism for the state of pectins to activate two different pathways. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc

    FaRIF Transcription Factor Plays a Key Role in the Regulation of Fruit Ripening in the Cultivated Strawberry Fragaria x ananassa

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    Strawberry is becoming a model for studying the molecular mechanism of ripening in non-climacteric fruits. However, a limited number of transcriptional regulators of this process have been identified so far. In this study, we have identified and characterized a gene encoding for a NAC transcription factor (TF), named as FaRIF (Ripening Inducing Factor). FaRIF expression presents a fruit-specific pattern, which is upregulated during ripening. In order to functionally characterize this TF, we have generated silencing (35S::RIF-RNAi) and overexpressing (35S::RIF-GFP) stable transgenic lines. While the RNAi lines showed an apparent delay of fruit ripening, the overexpressing lines displayed an acceleration of this process. Transcriptomic analysis, by RNA-seq, of the silenced lines showed a significantly altered expression of genes involved in the flavonoids pathway, as well as genes of the metabolism of the main sugars of the fruit. Metabolomics analysis confirmed these changes in the transgenic fruits. Both, transcriptomic and metabolomics data, were in agreement with the general phenotype observed in the fruits of the FaRIF-silenced lines. All together, our results support a main role of FaRIF in the control of relevant ripening-associated processes in strawberry fruit.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Selection of processing parameters in laser microwelding. Part 1: Continuous wave (CW) mode

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    A phenomenological model which specifies the penetration depth and width of the fusion zone in laser microjoining can be a very useful tool in achieving the required welding parameters for a desired application. In this study the power factor model, previously established and validated in macrowelding, has been tested in fibre laser microwelding, enabling achievement of a particular weld independently of a laser system. Differ-ent weld profiles in aluminium and stainless steel were correlated with various combinations of parameters for a wide range of beam diameters. It has been shown that the same penetration depth can be achieved with different weld profiles. A similar trend, as previously found in macrow-elding, has been confirmed in microwelding. It was demonstrated that the depth of penetration can be kept constant independently of the laser sys-tem until certain limit of beam size

    The NAC transcription factor FaRIF is a key regulator of fruit ripening in strawberry

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    In contrast to climacteric fruits such as tomato, the knowledge on key regulatory genes controlling the ripening of strawberry, a non-climacteric fruit, is still limited. NAC transcription factors are proteins that mediate different developmental processes in plants. In this work, we have identified and characterized FaRIF (Ripening Inducing Factor), a novel NAC transcription factor which is highly expressed and induced in strawberry receptacles during ripening. Functional analysis establishing stable transgenic lines with RNAi, driven by either the constitutive 35S or the ripe receptacle-specific EXP2 promoters, and overexpression constructs showed that FaRIF controls critical ripening-related processes such as fruit softening and pigment and sugars accumulation. Physiological, metabolomic and transcriptomic analyses of receptacles of FaRIFsilenced and overexpression lines point to FaRIF as a key regulator of strawberry fruit ripening from early developmental stages, controlling ABA biosynthesis and signaling, cell wall degradation and modification, the phenylpropanoid pathway, and the balance of the aerobic/anaerobic metabolism, being therefore a target to be modified/edited to control the quality of strawberry fruits.ERC Starting Grant ERC-2014-StG 63813

    Identification and characterization of the NAC transcription factor FaRIF, a key regulator of strawberry fruit ripening

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    Strawberry is becoming a model for studying the molecular mechanism of ripening in non-climacteric fruits. However, a limited number of transcriptional regulators of this process have been identified so far. In this study, we have identified and characterized a gene encoding for a NAC transcription factor (TF), named as FaRIF (Ripening Inducing Factor). FaRIF expression presents a fruit-specific pattern, which is upregulated during ripening. In order to functionally characterize this TF, we have generated silencing and overexpressing stable transgenic lines. While the RNAi lines showed an apparent delay of fruit ripening, the overexpressing lines displayed an acceleration of this process. Transcriptomic analysis of the silenced lines showed a significantly altered expression of genes involved in development, hormone metabolism, flavonoid pathway, and cell-wall disassembly, being many of these confirmed by phenotypical and metabolomics analysis. Our results support a main role of FaRIF in the control of relevant ripening-associated processes in strawberry fruit

    Extralimital Senegalese species during Marine Isotope Stages 5.5 and 11 in the Canary Islands (29° N): Sea surface temperature estimates

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    The presence of Harpa doris Röding, 1798 in marine deposits of the last interglacial period, ~130-120 ka (marine isotope stage or MIS 5.5) in the Canary Islands (Gran Canaria, Lanzarote and Fuerteventura) enabled us to compare this occurrence with its present habitat in the Gulf of Guinea and the Cape Verde Islands, well to the south. This comparison leads to the conclusion that sea surface temperatures (SSTs) in the waters around the Canary Islands during the last interglacial period were at least 3.3 °C higher than today. H. doris is found in association with the large gastropod Persististrombus latus (Gmelin, 1791) as well as the coral Siderastrea radians (Pallas, 1766). The presence of these extralimital southern,warm-water species in the Canary Islands during the last interglacial period also implies a northward expansion of plankton-feeding larvae in seawater with a high chlorophyll-a content. Such conditionswould require a shortening of the southern arm of the cool Canary Current that dominates the waters around the Canary Islands at present. Marine deposits dating to ~400 ka (MIS 11) are also found on the Canary Islands. In these deposits, the presence of Saccostrea cucullata (Born, 1778) allows a comparison with its present habitat in the Gulf of Guinea. In this analysis, we conclude that SSTs in waters around the Canary Islands during this major interglacial period were at least 4.2 °C higher than today. Middle Pleistocene fossils of S. cucullata have also been found in the western Mediterranean Sea and Morocco, as well as the Cape Verde Islands. If these deposits also date to MIS 11, SST warming could have been a regional phenomenon, including much of the eastern Atlantic Ocean and Mediterranean Sea

    A phase II study of Yondelis® (trabectedin, ET-743) as a 24-h continuous intravenous infusion in pretreated advanced breast cancer

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    Yondelis® (trabectedin, ET-743) is a novel marine-derived anticancer compound found in the ascidian Ecteinascidia turbinata. It is currently under phase II/III development in breast cancer, hormone refractory prostate cancer, sarcomas and ovarian cancer. Activity in breast cancer experimental models has been reported, and preliminary evidence of activity in this setting during the phase I programme has also been observed. The present study assessed the activity and feasibility of trabectedin in women with advanced breast cancer previously treated with conventional therapies. Patients with advanced disease previously treated with at least one but not more than two regimens that included taxanes or anthracyclines as palliative therapy were eligible. Trabectedin 1.5 mg m−2 was administered as a 24-h continuous infusion every 3 weeks. Patients were kept on therapy until disease progression, unacceptable toxicity or patient refusal. Twenty-seven patients were included between April 1999 and September 2000. Their median age was 54 years (range: 36–67) and 63% of them had two metastatic sites. Twenty-two patients were performance status 1. All patients had previously received anthracyclines, and 23 out of 27 patients had received taxanes. Of 21 patients with measurable disease, three confirmed partial responses, one unconfirmed partial response and two minor responses (49 and 32% tumour shrinkage) were observed; six patients had stable disease. Median survival was 10 months (95% confidence interval: 4.88–15.18). Transient and noncumulative transaminitis was observed in most of the patients. The pharmacokinetic profile of trabectedin in this patient's population is in line with the overall data available with this schedule. The policy of dose adjustments based on the intercycle peaks of bilirubin and alkaline phosphatase appears to have a positive impact in the therapeutic index of trabectedin. Trabectedin can induce response and tumour control in previously treated advanced breast cancer, with manageable toxicity, thus warranting further development as a single agent or in combination regimens
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