18 results on '"Lucas Bustamante"'
Search Results
2. Two new glassfrogs (Centrolenidae: Hyalinobatrachium) from Ecuador, with comments on the endangered biodiversity of the Andes
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Juan M. Guayasamin, Rebecca M. Brunner, Anyelet Valencia-Aguilar, Daniela Franco-Mena, Eva Ringler, Anderson Medina Armijos, Carlos Morochz, Lucas Bustamante, Ross J. Maynard, and Jaime Culebras
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Andes ,Amphibia ,Conservation ,Cryptic diversity ,Mining ,Ecuador ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background The Tropical Andes is the world’s most biodiverse hotspot. This region contains >1,000 amphibian species, more than half of which are endemic. Herein we describe two new glassfrog species (Centrolenidae: Hyalinobatrachium) that we discovered within relatively unexplored and isolated localities of the Ecuadorian Andes. Methods We employed morphological, acoustic, and molecular methods to test the hypothesis that Hyalinobatrachium mashpi sp. nov and H. nouns sp. nov. are species new to science. Following standard methods, we generated mitochondrial sequences (16S) of 37 individuals in the genus Hyalinobatrachium. We inferred the phylogenetic relationships of the two new species in comparison to all other glassfrogs using Maximum Likelihood. In addition to describing the call of H. mashpi sp. nov., we performed a discriminant analysis of principal components (DAPC) with the advertisement call characteristics of several congeners. Results Based on an integrative taxonomy approach, we describe two new species. Morphological traits and the inferred phylogeny unambiguously place the new taxa in the genus Hyalinobatrachium. Both species are distinguished from other glassfrogs mainly by their dorsal coloration (i.e., dorsum lime green with small light yellow spots, head usually with interorbital bar) and transparent pericardium (i.e., the heart is visible through the ventral skin). The new species exhibit a high morphological similarity (i.e., cryptic) and occur within relatively close geographical proximity (closest aerial distance = 18.9 km); however, their uncorrected p distance for the mitochondrial gene 16S is 4.6–4.7%, a value that greatly exceeds the genetic distance between closely related species of centrolenid frogs. The DAPC revealed that the advertisement call of H. mashpi sp. nov. is acoustically distinct. Discussion Our findings are congruent with several previous studies that report a high degree of endemism in the Toisán mountain range, which appears to be isolated from the main Andean cordillera for some amphibian groups. We recommend that both H. mashpi sp. nov. and H. nouns sp. nov. be listed as Endangered, following IUCN criteria. These new species provide another example of cryptic diversity in the Andes—further evidence that the region fosters much more biodiversity than we have the resources to catalog. Threatened by mining and other exploitative industries, these glassfrogs and many other yet-to-be-discovered Andean species highlight the dire need for effective conservation measures—especially in northwestern Ecuador.
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- 2022
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3. Comparative Phylogeography Reveals Cryptic Diversity and Repeated Patterns of Cladogenesis for Amphibians and Reptiles in Northwestern Ecuador.
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Alejandro Arteaga, R Alexander Pyron, Nicolás Peñafiel, Paulina Romero-Barreto, Jaime Culebras, Lucas Bustamante, Mario H Yánez-Muñoz, and Juan M Guayasamin
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Medicine ,Science - Abstract
Comparative phylogeography allow us to understand how shared historical circumstances have shaped the formation of lineages, by examining a broad spectrum of co-distributed populations of different taxa. However, these types of studies are scarce in the Neotropics, a region that is characterized by high diversity, complex geology, and poorly understood biogeography. Here, we investigate the diversification patterns of five lineages of amphibians and reptiles, co-distributed across the Choco and Andes ecoregions in northwestern Ecuador. Mitochondrial DNA and occurrence records were used to determine the degree of geographic genetic divergence within species. Our results highlight congruent patterns of parapatric speciation and common geographical barriers for distantly related taxa. These comparisons indicate similar biological and demographic characteristics for the included clades, and reveal the existence of two new species of Pristimantis previously subsumed under P. walkeri, which we describe herein. Our data supports the hypothesis that widely distributed Chocoan taxa may generally experience their greatest opportunities for isolation and parapatric speciation across thermal elevational gradients. Finally, our study provides critical information to predict which unstudied lineages may harbor cryptic diversity, and how geology and climate are likely to have shaped their evolutionary history.
- Published
- 2016
- Full Text
- View/download PDF
4. Reptiles of Ecuador: life in the middle of the world
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Alejandro Arteaga, Lucas Bustamante, Jose Vieira, and Juan M. Guayasamin
- Abstract
We present the book “Reptiles of Ecuador,” a comprehensive monographic catalogue about every single one of Ecuador’s 494 non-avian reptiles. This updated field guide is designed to be used primarily as a tool to identify species in the field and is written so that it can be easily understood by any reader. It includes photographs, illustrations, and distribution maps covering all reptiles in the country. It also summarizes novel as well as historical information about each species and presents it in the form of individual accounts. Each account includes the following sections: names, recognition, natural history, distribution, conservation, etymology, see it in the wild, and references.
- Published
- 2022
5. Reptiles of the Galápagos: Life on the Enchanted Islands
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Washington Tapia, Alejandro Arteaga, Jose Vieira, Juan M. Guayasamin, and Lucas Bustamante
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Geography - Published
- 2019
6. Real-time DNA barcoding in a rainforest using nanopore sequencing: opportunities for rapid biodiversity assessments and local capacity building
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César L. Barrio-Amorós, David Salazar-Valenzuela, Stefan Prost, Luis A. Coloma, Nicolás Peñafiel, Alejandro Arteaga, Aaron Pomerantz, Lucas Bustamante, and Frank Pichardo
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0301 basic medicine ,Rainforest ,Computer science ,portable ,Biodiversity ,Endangered species ,field-based ,real-time ,Health Informatics ,Pomerantz [BRII recipient] ,DNA barcoding ,03 medical and health sciences ,symbols.namesake ,Nanopores ,Animals ,Sanger sequencing ,Research ,Life Sciences ,Reptiles ,Sequence Analysis, DNA ,Data science ,Biodiversity hotspot ,Computer Science Applications ,Nanopore ,030104 developmental biology ,Minion ,nanopore sequencing ,symbols ,Nanopore sequencing ,Ecuador - Abstract
Background Advancements in portable scientific instruments provide promising avenues to expedite field work in order to understand the diverse array of organisms that inhabit our planet. Here, we tested the feasibility for in situ molecular analyses of endemic fauna using a portable laboratory fitting within a single backpack in one of the world's most imperiled biodiversity hotspots, the Ecuadorian Chocó rainforest. We used portable equipment, including the MinION nanopore sequencer (Oxford Nanopore Technologies) and the miniPCR (miniPCR), to perform DNA extraction, polymerase chain reaction amplification, and real-time DNA barcoding of reptile specimens in the field. Findings We demonstrate that nanopore sequencing can be implemented in a remote tropical forest to quickly and accurately identify species using DNA barcoding, as we generated consensus sequences for species resolution with an accuracy of >99% in less than 24 hours after collecting specimens. The flexibility of our mobile laboratory further allowed us to generate sequence information at the Universidad Tecnológica Indoamérica in Quito for rare, endangered, and undescribed species. This includes the recently rediscovered Jambato toad, which was thought to be extinct for 28 years. Sequences generated on the MinION required as few as 30 reads to achieve high accuracy relative to Sanger sequencing, and with further multiplexing of samples, nanopore sequencing can become a cost-effective approach for rapid and portable DNA barcoding. Conclusions Overall, we establish how mobile laboratories and nanopore sequencing can help to accelerate species identification in remote areas to aid in conservation efforts and be applied to research facilities in developing countries. This opens up possibilities for biodiversity studies by promoting local research capacity building, teaching nonspecialists and students about the environment, tackling wildlife crime, and promoting conservation via research-focused ecotourism.
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- 2018
7. Molecular phylogeny of stream treefrogs (Hylidae:Hyloscirtus bogotensisGroup), with a new species from the Andes of Ecuador
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Jaime Culebras, Carl R. Hutter, Nicolás Peñafiel, Carlos Morochz, Mauricio Rivera-Correa, R. Alexander Pyron, Alejandro Arteaga, Juan M. Guayasamin, and Lucas Bustamante
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Global and Planetary Change ,Ecology ,biology ,Zoology ,biology.organism_classification ,Hyloscirtus armatus ,Hylidae ,Hyloscirtus ,Hyloscirtus bogotensis ,Phylogenetics ,Molecular phylogenetics ,Taxonomy (biology) ,Clade ,Ecology, Evolution, Behavior and Systematics - Abstract
We present a new molecular phylogeny of the stream treefrog genus Hyloscirtus, with an improved taxon sampling in the Hyloscirtus bogotensis group. The tree supports the existence of three clades within the genus (Hyloscirtus armatus group, H. bogotensis group and Hyloscirtus larinopygion group) in congruence with previous studies, and suggests the presence of at least three new species in the H. bogotensis group. Herein, we describe one of these species, Hyloscirtus mashpi n. sp. from the Pacific slope of the Ecuadorian Andes. The validity of the latter is supported by molecular, morphological and acoustic data. We also tested individuals of the new species for the chytrid fungus Batrachochytrium dendrobatidis, finding a prevalence of 17.6% (6 positives and 28 negatives). However, at sampled streams, frog densities were high, suggesting that H. mashpi n. sp. may be tolerant to the infection.
- Published
- 2015
8. Real-time DNA barcoding in a remote rainforest using nanopore sequencing
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César L. Barrio-Amorós, Stefan Prost, Aaron Pomerantz, Luis A. Coloma, Nicolás Peñafiel, Frank Pichardo, Lucas Bustamante, Alejandro Arteaga, and David Salazar-Valenzuela
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DNA sequencer ,Evolutionary biology ,Ecology ,Minion ,Rare species ,Atelopus ignescens ,Endangered species ,Nanopore sequencing ,Biology ,biology.organism_classification ,DNA extraction ,DNA barcoding - Abstract
Advancements in portable scientific instruments provide promising avenues to expedite field work in order to understand the diverse array of organisms that inhabit our planet. Here we tested the feasibility for in situ molecular analyses of endemic fauna using a portable laboratory fitting within a single backpack, in one of the world’s most imperiled biodiversity hotspots: the Ecuadorian Chocó rainforest. We utilized portable equipment, including the MinION DNA sequencer (Oxford Nanopore Technologies) and miniPCR (miniPCR), to perform DNA extraction, PCR amplification and real-time DNA barcode sequencing of reptile specimens in the field. We demonstrate that nanopore sequencing can be implemented in a remote tropical forest to quickly and accurately identify species using DNA barcoding, as we generated consensus sequences for species resolution with an accuracy of >99% in less than 24 hours after collecting specimens. In addition, we generated sequence information at Universidad Tecnológica Indoamérica in Quito for the recently re-discovered Jambato toad Atelopus ignescens, which was thought to be extinct for 28 years, a rare species of blind snake Trilepida guayaquilensis, and two undescribed species of Dipsas snakes. In this study we establish how mobile laboratories and nanopore sequencing can help to accelerate species identification in remote areas (especially for species that are difficult to diagnose based on characters of external morphology), be applied to local research facilities in developing countries, and rapidly generate information for species that are rare, endangered and undescribed, which can potentially aid in conservation efforts.
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- 2017
- Full Text
- View/download PDF
9. Comparative Phylogeography Reveals Cryptic Diversity and Repeated Patterns of Cladogenesis for Amphibians and Reptiles in Northwestern Ecuador
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Juan M. Guayasamin, Nicolás Peñafiel, Alejandro Arteaga, R. Alexander Pyron, Mario H. Yánez-Muñoz, Paulina Romero-Barreto, Lucas Bustamante, and Jaime Culebras
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0106 biological sciences ,Biodiversity ,lcsh:Medicine ,Parapatric speciation ,Forests ,01 natural sciences ,Biochemistry ,Geographical locations ,Medicine and Health Sciences ,lcsh:Science ,Musculoskeletal System ,Energy-Producing Organelles ,Phylogeny ,Data Management ,Skin ,Multidisciplinary ,Geography ,Ecology ,New Species Reports ,Terrestrial Environments ,Biological Evolution ,Mitochondria ,Phylogeography ,Biogeography ,Vertebrates ,Legs ,Ecuador ,Anatomy ,Integumentary System ,Cellular Structures and Organelles ,Research Article ,Computer and Information Sciences ,Genetic Speciation ,010607 zoology ,Biology ,Bioenergetics ,010603 evolutionary biology ,DNA, Mitochondrial ,Ecosystems ,Amphibians ,Genetics ,Pristimantis ,Animals ,Taxonomy ,Evolutionary Biology ,Population Biology ,lcsh:R ,Ecology and Environmental Sciences ,Limbs (Anatomy) ,Organisms ,Biology and Life Sciences ,Eyelids ,Reptiles ,Genetic Variation ,Cell Biology ,15. Life on land ,Toes ,South America ,biology.organism_classification ,Genetic divergence ,Cladogenesis ,Genetics, Population ,Amniotes ,Earth Sciences ,lcsh:Q ,Feet (Anatomy) ,People and places ,Population Genetics - Abstract
Comparative phylogeography allow us to understand how shared historical circumstances have shaped the formation of lineages, by examining a broad spectrum of co-distributed populations of different taxa. However, these types of studies are scarce in the Neotropics, a region that is characterized by high diversity, complex geology, and poorly understood biogeography. Here, we investigate the diversification patterns of five lineages of amphibians and reptiles, co-distributed across the Choco and Andes ecoregions in northwestern Ecuador. Mitochondrial DNA and occurrence records were used to determine the degree of geographic genetic divergence within species. Our results highlight congruent patterns of parapatric speciation and common geographical barriers for distantly related taxa. These comparisons indicate similar biological and demographic characteristics for the included clades, and reveal the existence of two new species of Pristimantis previously subsumed under P. walkeri, which we describe herein. Our data supports the hypothesis that widely distributed Chocoan taxa may generally experience their greatest opportunities for isolation and parapatric speciation across thermal elevational gradients. Finally, our study provides critical information to predict which unstudied lineages may harbor cryptic diversity, and how geology and climate are likely to have shaped their evolutionary history.
- Published
- 2016
10. Quantification of fire gases by FTIR: Experimental characterisation of calibration systems
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Peter Fardell, Anna A. Stec, Eric Guillaume, Per Blomqvist, Lucas Bustamante-Valencia, and Laurent Saragoza
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Hydrogen ,business.industry ,Sample (material) ,General Physics and Astronomy ,chemistry.chemical_element ,Infrared spectroscopy ,General Chemistry ,Combustion ,medicine.disease ,chemistry ,Forensic engineering ,medicine ,Calibration ,General Materials Science ,Fourier transform infrared spectroscopy ,Safety, Risk, Reliability and Quality ,Process engineering ,business ,Vapours ,Water vapor - Abstract
Gaseous fire effluents contain a mixture of components, some of which are present in toxicologically significant proportions, together with water vapour and particulate matter, representing a significant challenge to the analyst. The most useful information is obtained from fire gases at about 180 °C where water and most organic species are volatile. Despite this, it is often necessary to sample and measure fire effluents for prediction of fire toxicity, estimation of the environmental impact of fires, and to understand their behaviour. Gas phase Fourier Transform Infrared (FTIR) spectroscopy has the potential to measure almost all volatiles on a continuous basis during fire. This paper considers the key parameters, which must be carefully measured and controlled in order to obtain reliable calibration data. It evaluates a number of techniques designed for calibrating an FTIR spectrometer for use in fire gas analysis with conclusions on the best system for use for each species and for specific fire tests or experimental scenarios. As few molecules in the gas phase infrared spectrum obey the Beer-Lambert law, a full set of infrared spectra at different concentrations must be obtained for each target analyte, for the actual spectrophotometer—gas cell configuration in use. In some cases, stable standard mixtures are available, and these only have to be quantitatively diluted. In other cases reactive gases such as hydrogen halides must be generated quantitatively in situ, or vapours must be generated from volatile liquids under controlled conditions, in order to obtain calibration spectra. In each case, care must be taken in the design of the sampling line and calibration system, paying particular attention to the temperature, pressure and gas flow. Gas phase FTIR is a powerful analytical tool, but requires a significant investment in time and equipment before quantitative analysis can be undertaken. Unless care is taken to ensure constant temperature and pressure in the sample lines and gas cell, significant errors will result.
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- 2011
11. Development of the Thermal Decomposition Mechanism of Polyether Polyurethane Foam Using Both Condensed and Gas-Phase Release Data
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Lucas Bustamante Valencia, Jocelyn Luche, Eric Guillaume, Franck Richard, Jose L. Torero, Guillermo Rein, and Thomas Rogaume
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Thermogravimetric analysis ,Reaction mechanism ,Chemistry ,General Chemical Engineering ,Thermal decomposition ,Analytical chemistry ,General Physics and Astronomy ,Energy Engineering and Power Technology ,General Chemistry ,Combustion ,Decomposition ,Thermogravimetry ,chemistry.chemical_compound ,Fuel Technology ,Chemical engineering ,Pyrolysis ,Polyurethane - Abstract
The thermal decomposition mechanism of solids is a main input data of codes in fire research. In this research, the evolution of thermal properties versus temperature is used together with the measurement of gas effluents to understand the decomposition of polyether polyurethane foam (PPUF). A wide characterization of the virgin fuel and the intermediary species that enter into the thermal process showed that a 5-step reaction mechanism is sufficient to describe the decomposition of the foam. The mechanism found is supposed chemically correct by the coupling study of the gaseous emissions. The kinetic constants of each of the 5 reactions are determined with the genetic algorithm method. The mechanism is used in a mathematical model in order to predict the mass loss rate at 4 heating rates and 2 atmospheres observed in thermogravimetric analysis. A good fitting between the experiments and the calculation results was found.
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- 2011
12. Carbonitriding: kinetic modeling of ammonia and acetylene decomposition at high temperature and low pressure
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Jie Sheng, Frédéric Richard, Lucas Bustamante-Valencia, Simon Jallais, Elena Vyazmina, and Pierre Bruchet
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Carbonitriding ,Materials science ,020209 energy ,Diffusion ,chemistry.chemical_element ,02 engineering and technology ,medicine.disease_cause ,Decomposition ,Soot ,Carburizing ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Acetylene ,Chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,General Materials Science ,0204 chemical engineering ,Carbon ,Pyrolysis - Abstract
The process of carbonitriding is similar to the process of carburization yet with additional ammonia to increase the hardness of the metal surface. Carbonitriding is performed at approximately 850 °C–880 °C, which is lower compare to carburizing and low pressure (10–50 mbar). The process consists of two stages: decomposition of ammonia and diffusion of “activated nitrogen”, and decomposition of acetylene and diffusion of carbon. The decomposition of acetylene is a very complex phenomenon, depending on the temperature, pressure and residence time (the time of presence of acetylene in a furnace). Different reaction products form: small molecules (H2, CH4, C2H4, C6H6, etc.), fine-crystalline graphite (the one that diffuses into the metal surface), polycyclic aromatic hydrocarbons (PAHs), soot etc. The current investigation is based on detailed kinetic modeling (using Chemkin 17.1) of the acetylene decomposition in the atmosphere of a reactor. For this modeling three different comprehensive mechanisms from the literature are considered: the mechanism of K. Norinaga (including 227 species, 827 reactions), the mechanism of T. Bensabath (including 364 species, 1245 reactions) and the mechanism of C. Saggese (including 350 species, more than 10,000 reactions). Comparison of simulation results with experimental data from the literature showed good agreement, demonstrating their applicability for modeling of industrial process. A parametric study suggests the best parameters for acetylene decomposition in a furnace.
- Published
- 2018
13. Modélisation du comportement au feu d'un composite par calcul de pyrolyse : approche combinée expérience-simulation à petite échelle
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Lucas Bustamante Valencia, Eric Guillaume, Michel Pavageau, Damien Marquis, and Carine Chivas
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Mechanical Engineering ,General Materials Science ,Industrial and Manufacturing Engineering - Abstract
Le travail presente dans ce document s'inscrit dans le cadre d'un projet de recherche francais de 3 ans dedie a l'utilisation de materiaux composites dans la construction navale. Dans ce projet, il est prevu d'utiliser le code CFD FDS-5 avec un modele de pyrolyse pour tenir compte de la contribution de cloisons en materiau composite sur le developpement du feu, dans le cadre de la simulation de scenarios incendies a bord d'un navire. Pour garantir la qualite de ces simulations, une methode de validation progressive des modeles utilises a ete suivie. Cette methode est basee sur une approche combinee experience-simulation a echelle croissante. Pour illustrer la demarche, on presente ici les resultats d'une etude experimentale du comportement au feu d'un echantillon de materiau composite, sur un banc d'essais a petite echelle, puis la simulation des essais correspondants.
- Published
- 2009
14. TESTING FIRE PROTECTIVE PERFORMANCE OF INTUMESCENT FLEXIBLE FOAM AND CORK MATERIAL USED FOR HIGH PRESSURE COMPOSITE CYLINDERS
- Author
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Dao, Duy Quang, Tran, Thu Hien, Rogaume, Thomas, Luche, Jocelyn, Richard, Franck, Batiot, Benjamin, and Valencia, Lucas Bustamante
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- 2015
- Full Text
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15. Systematics of Nothopsini (Serpentes, Dipsadidae), with a new species of Synophis from the Pacific Andean slopes of southwestern Ecuador
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Nicolás Peñafiel, Robert Alexander Pyron, Alejandro Arteaga, Juan M. Guayasamin, and Lucas Bustamante
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0106 biological sciences ,Systematics ,Species complex ,Reptilia ,Lialis ,Zoology ,Amniota ,Biology ,Tribe (biology) ,010603 evolutionary biology ,01 natural sciences ,Dipsadidae ,03 medical and health sciences ,Monophyly ,Gnathostomata ,Genus ,Squamata ,Branchiostoma capense ,Animalia ,Chordata ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Vertebrata ,Synapomorphy ,Craniata ,0303 health sciences ,Serpentes ,Ymeria ,Reptiliomorpha ,Dipsadinae ,Colubridae ,Cephalornis ,SerpentesAnimalia ,15. Life on land ,Incertae sedis ,Nothopsini ,Diaphorolepis ,Synophis ,Animal Science and Zoology ,Research Article - Abstract
Within Dipsadinae, some recent authors have recognized a tribe Nothopsini containing the genera Diaphorolepis, Emmochliophis, Nothopsis, Synophis, and Xenopholis, on the basis of a number of putative morphological synapomorphies. However, molecular results suggest that Nothopsis, Synophis, and Xenopholis do not form a monophyletic group, while the remaining taxa are unsampled in recent molecular phylogenies. Here, DNA-sequence data for some Diaphorolepis and Synophis species are provided for the first time, as well as additional new sequences for Nothopsis and some Synophis species. Including these and other existing data for nothopsine species, previous studies showing that Nothopsini is not a natural group are corroborated. Nothopsini Cope, 1871 is restricted to Nothopsis. Diaphorolepidini Jenner, 1981 is resurrected and re-delimited to include only Diaphorolepis, Emmochliophis, and Synophis. Finally, Xenopholis remains Dipsadinae incertae sedis. Known material of Diaphorolepidini is reviewed to generate revised and expanded descriptions and diagnoses at the tribe, genus, and species level. Numerous cryptic species are likely present in Synophis bicolor and Synophis lasallei. Finally, a new population from the low-elevation cloud forests of SW Ecuador is reported upon, which is genetically and morphologically distinct from all other species, that is here named Synophis zaheri sp. n.
- Published
- 2015
16. Thermal degradation of epoxy resin/carbon fiber composites: Influence of carbon fiber fraction on the fire reaction properties and on the gaseous species release
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Jocelyn Luche, Frank Richard, Sindonie Ruban, Thomas Rogaume, Duy Quang Dao, and Lucas Bustamante Valencia
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Materials science ,Polymers and Plastics ,Thermal resistance ,Metals and Alloys ,General Chemistry ,Calorimetry ,Gas analyzer ,Electronic, Optical and Magnetic Materials ,Combustibility ,Volume (thermodynamics) ,Cone calorimeter ,Volume fraction ,Ceramics and Composites ,Heat of combustion ,Composite material - Abstract
Summary The thermal degradation of epoxy resin/carbon fiber composites has been performed in ISO 5660 standard cone calorimeter using a piloted ignition. Two kinds of composites that differ by their volume fractions in carbon fiber (56 and 59 vol.%) were tested in this study. The cone calorimeter irradiance level was increased up to 75 kW m−2 to characterize the carbon fiber volume fraction influence on the composite thermal degradation. Thus, main flammability and combustibility parameters were determined and calculated such as mass loss, mass loss rate, ignition time, thermal response parameter, ignition temperature, thermal inertia, and heat of gasification. As a result, all the characteristic parameters for the thermal resistance of composites were decreased when the carbon fiber volume fraction increased. Moreover, the main gaseous products (such as NO, CO, CO2, HCN, H2O, and lightweight hydrocarbons) emitted as well as the oxygen consumption during the composite thermal decomposition were also quantified simultaneously with a portable gas analyzer and a Fourier transform infrared spectrometer. The main species emission yields calculated from the gas analysis results increased slightly when the carbon fiber volume fraction was increased in the initial sample. The epoxy composite was represented as a sooty material with a significant production of soot particles during the combustion process. Furthermore, heat release rate, total heat release, and effective heat of combustion were calculated by using the oxygen consumption calorimetry technique. The results obtained showed that a small increasing of composite carbon fiber amount induced a sharp decrease of heat release rate and total heat release. Copyright © 2014 John Wiley & Sons, Ltd.
- Published
- 2014
17. Analysis of Principal Gas Products During Combustion of Polyether Polyurethane Foam at Different Irradiance Levels
- Author
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Lucas Bustamante Valencia, Eric Guillaume, Jose L. Torero, Thomas Rogaume, Guillermo Rein, Laboratoire de combustion et de détonique (LCD), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
- Subjects
flame retardant ,Irradiance ,General Physics and Astronomy ,020101 civil engineering ,02 engineering and technology ,Combustion ,0201 civil engineering ,chemistry.chemical_compound ,Cone calorimeter ,calorimeter ,General Materials Science ,Safety, Risk, Reliability and Quality ,FID ,Valencia ,ComputingMilieux_MISCELLANEOUS ,Polyurethane ,[PHYS]Physics [physics] ,decomposition ,biology ,General Chemistry ,Polyether polyurethane ,021001 nanoscience & nanotechnology ,biology.organism_classification ,pyrolysis ,PPUF ,chemistry ,Chemical engineering ,FTIR ,13. Climate action ,Environmental science ,0210 nano-technology - Abstract
This paper is part of the PhD thesis of Dr Lucas Bustamante Valencia, accessible at http://www.era.lib.ed.ac.uk/handle/1842/3209. This paper studies the release of the principal gas species produced during the combustion of a non-flame-retarded Polyether Polyurethane Foam (PPUF) of density of 20.9 kg/m^3 in the cone calorimeter. Five irradiance levels are studied: 10, 20, 30, 40, and 50 kW/m^2. Heat release rate, mass loss rate and bulk gas mass flow are measured. The mass flow and yields of gas species are measured as well. The analysis of release of gas species relative to time allowed to study the different stages of PPUF kinetics and to quantify the gas composition. Of the twenty two different gas species that were monitored simultaneously, the principal species found were CO2, CO, H2O, NO and total hydrocarbons. According to species release, two decomposition stages for PPUF are identified. In the first stage, the solid structure breaks down carrying the decomposition of isocyanate, and in the second stage the polyol decomposes. These two stages are in agreement with the decomposition mechanism proposed in literature. However, the data presented here is the first experimental study of burning behavior of PPUF taking into account the release of gas species too. An elemental analysis was performed and the chemical formula of the virgin material was determined. This allows the mass balance of the elements in the virgin foam content with the gaseous product content. The effective heat of combustion and the ratio between heat release rate and CO2 mass flow are calculated at each of the irradiance levels.
- Published
- 2009
18. Development of the Thermal Decomposition Mechanism of Polyether Polyurethane Foam Using Both Condensed and Gas-Phase Release Data
- Author
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Rogaume, Thomas, primary, Valencia, Lucas Bustamante, additional, Guillaume, Eric, additional, Richard, Franck, additional, Luche, Jocelyn, additional, Rein, Guillermo, additional, and Torero, Jose Luis, additional
- Published
- 2011
- Full Text
- View/download PDF
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