2,973 research outputs found
3D MODELLING OF THE NEGRO TOWER FOR ITS COMPREHENSIVE ANALYSIS AND A CONSERVATION PROPOSAL
Abstract. The Negro Tower, in El Algar, Cartagena (Region of Murcia, Spain), is a building which dates to 1585. It is a tower built in a rural environment, inland from the coast, to alert and protect the population from pirate attacks. It was part of the network of watchtowers and defense posts along the coast of Murcia built between the sixteenth and seventeenth centuries. The tower is protected as a historical monument, but its state of conservation is very poor. For this reason, a comprehensive study has been carried out to ensure its correct restoration and future conservation. Historical and constructive analysis has allowed us to discover the social, cultural and architectural characteristics of the tower. Digital photogrammetry and 3D laser scanning compatible with classic topography have been used for the graphic survey of the tower. All this information has permitted the elaboration of thorough three-dimensional modelling and the proposal of a volumetric recomposition of the tower. The presentation will set out the working methodology followed as well as the important results achieved. This research work aims to contribute to the recognition and correct conservation of the Tower. The graphic survey and the three-dimensional model obtained will allow the recovery of the tower and its integration into the natural environment
Biomagnification of metals and organic pollutants in sea snail (Murex trunculus) from cockle (Cerastoderma glaucum) in the Mar Menor lagoon (SE Spain)
Predicting global geographical distribution of "Lolium rigidum" under climate change
“Lolium rigidum Gaud.” (vallico) es una de las malezas más extendidas y perjudiciales en los cultivos de cereales de invierno. Un modelo bioclimático para esta especie fue desarrollado utilizando CLIMEX. El modelo fue validado con los registros de esta especie en Estados Unidos y Oceanía y utilizado para predecir la distribución potencial global de “L. rigidum” bajo el clima actual y dos escenarios de cambio climático. Las proyección en virtud de las condiciones climáticas actuales indican que “L. rigidum” no ocupa todo el área disponible para su expansión. Considerando los escenarios climáticos futuros, el área potencial de expansión aumentará 3,79% y 5,06% bajo los escenarios moderado y extremo, respectivamente. La proyección del modelo mostró un avance gradual de “L. rigidum” en Norteamérica, Europa, Sudamérica y Asia, mientras que en África y Oceanía se prevé una regresión. Estos resultados proporcionan Los conocimientos necesarios para identificar y poner de relieve las posibles zonas de riesgo de invasión.“Lolium rigidum” Gaud. (rigid ryegrass) is one of the most extended and harmful weeds in winter cereal crops. A bioclimatic model for this species was developed using CLIMEX. The model was validated with records from North America and Oceania and used to assess the global potential distribution of “L. rigidum” under the current climate and under two climate change scenarios. The projection under current climate conditions indicated that “L. rigidum” does not occupy the full extent of the climatically suitable area available to it. Under future climate scenarios, the infested potential area will increase 3.79% in the low-emission CO2 scenario and 5.06% under the most extreme scenario. The model projection showed a gradual advance of rigid ryegrass in North America, Europe, South America and Asia, whilst in Africa and Oceania it indicated regression. These results provide the necessary knowledge for identifying and highlighting the potential invasion risk areas
Dynamic characterisation of interlaminar fracture toughness in carbon fibre epoxy composite laminates
In this work, the rate dependence of mode I interlaminar fracture toughness for two different materials systems,
IM7/8552 and IM7/M91, both unidirectional UD carbon-fibre epoxy composite laminates have been examined
over a wide range of loading rates from 0.5 mm/min up to 2000 mm/s at room temperature. Quasi-static fracture
tests were performed using a DCB (double-cantilever beam) method with a screw-driven testing machine, while
the dynamic tests were carried out using a WIF (wedge-insert fracture) specimen loaded dynamically in a hydraulic
system. For performing the tests at high displacement rates, a special setup was designed and manufactured
which allowed the insertion of the wedge within the DCB specimens at different cross-head displacement
rates. The experimental technique used a pair of strain gauges attached to the bending surface of one of the
arms of the cantilever beams and far from the initial crack tip. The peak values of the recorded strain were used
to determine the fracture toughness under dynamic conditions through use of the compliance calibration
method. A finite element model was developed to check the consistency of the measurements and validate the
data reduction method used. The results exhibited rate insensitive behaviour in the case of the IM7/8552 laminates
while IM7/M91 showed the contrary behaviour with maximum peak at 500 mm/s of displacement rate,
with a toughness increase of 95% with respect to the quasi-static conditions.The research leading to these results has received funding from the European Union as Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 722096, DYNACOMP project
Identification and functional analysis of novel phosphorylation sites in the RNA surveillance protein Upf1.
One third of inherited genetic diseases are caused by mRNAs harboring premature termination codons as a result of nonsense mutations. These aberrant mRNAs are degraded by the Nonsense-Mediated mRNA Decay (NMD) pathway. A central component of the NMD pathway is Upf1, an RNA-dependent ATPase and helicase. Upf1 is a known phosphorylated protein, but only portions of this large protein have been examined for phosphorylation sites and the functional relevance of its phosphorylation has not been elucidated in Saccharomyces cerevisiae. Using tandem mass spectrometry analyses, we report the identification of 11 putative phosphorylated sites in S. cerevisiae Upf1. Five of these phosphorylated residues are located within the ATPase and helicase domains and are conserved in higher eukaryotes, suggesting a biological significance for their phosphorylation. Indeed, functional analysis demonstrated that a small carboxy-terminal motif harboring at least three phosphorylated amino acids is important for three Upf1 functions: ATPase activity, NMD activity and the ability to promote translation termination efficiency. We provide evidence that two tyrosines within this phospho-motif (Y-738 and Y-742) act redundantly to promote ATP hydrolysis, NMD efficiency and translation termination fidelity
A new species of Websterinereis from the Gulf of California and redescription of Websterinereis foli (Fauvel, 1930) (Annelida, Nereididae)
A new species of Websterinereis Pettibone, 1971, W. pettiboneae sp. n. is described from La Paz Bay, Gulf
of California, Mexico. This species is similar to W. foli (Fauvel, 1930) in the neuropodial falcigers shape,
but can be separated by the tentacular cirri length, notopodial prechaetal lobe shape, and the size of the
notopodial dorsal and ventral ligules on posterior parapodia. Websterinereis foli is redescribed based upon
type material. Additional observations on the inter-annual density variation of W. pettiboneae sp. n. during
a four-year study are also provided. A key to all species of Websterinereis is included
tempo and mode of allopatric divergence in the weakly electric fish Sternopygus dariensis in the Isthmus of Panama
Spatial isolation is one of the main drivers of allopatric speciation, but the extent to which spatiallysegregated populations accumulate genetic differences relevant to speciation is not always clear. We used data from ultraconserved elements (UCEs) and whole mitochondrial genomes (i.e., mitogenomes) to explore genetic variation among allopatric populations of the weakly electric fish Sternopygus dariensis across the Isthmus of Panama. We found strong genetic divergence between eastern and western populations of S. dariensis. Over 77% of the UCE loci examined were differentially fixed between populations, and these loci appear to be distributed across the species’ genome. Population divergence occurred within the last 1.1 million years, perhaps due to global glaciation oscillations during the Pleistocene. Our results are consistent with a pattern of genetic differentiation under strict geographic isolation, and suggest the presence of incipient allopatric species within S. dariensis. Genetic divergence in S. dariensis likely occurred in situ, long after the closure of the Isthmus of Panama. Our study highlights the contribution of spatial isolation and vicariance to promoting rapid diversification in Neotropical freshwater fishes. The study of spatially-segregated populations within the Isthmus of Panama could reveal how genetic differences accumulate as allopatric speciation proceeds.Spatial isolation is one of the main drivers of allopatric speciation, but the extent to which spatiallysegregated populations accumulate genetic differences relevant to speciation is not always clear. We used data from ultraconserved elements (UCEs) and whole mitochondrial genomes (i.e., mitogenomes) to explore genetic variation among allopatric populations of the weakly electric fish Sternopygus dariensis across the Isthmus of Panama. We found strong genetic divergence between eastern and western populations of S. dariensis. Over 77% of the UCE loci examined were differentially fixed between populations, and these loci appear to be distributed across the species’ genome. Population divergence occurred within the last 1.1 million years, perhaps due to global glaciation oscillations during the Pleistocene. Our results are consistent with a pattern of genetic differentiation under strict geographic isolation, and suggest the presence of incipient allopatric species within S. dariensis. Genetic divergence in S. dariensis likely occurred in situ, long after the closure of the Isthmus of Panama. Our study highlights the contribution of spatial isolation and vicariance to promoting rapid diversification in Neotropical freshwater fishes. The study of spatially-segregated populations within the Isthmus of Panama could reveal how genetic differences accumulate as allopatric speciation proceeds
Levels and spatial distribution of organochlorinated compounds and polycyclic aromatic hydrocarbons in fishes from a Mediterranean coastal lagoon
The seasonal input and distribution of organic contaminants in the Mar Menor lagoon have been recently characterized in seawater and sediments, showing the significant impact of flash flood events. Mar Menor is a hypersaline (42-47 psu) coastal lagoon located in the Cartagena Field area at the South East of Spain subjected mainly to intensive agriculture, seasonal tourism and recreational activities. The bioaccumulation of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs) has been also determined in bivalves, but no information was available about their accumulation in fishes. In this study the concentrations of PAHs, PCBs and OCPs in golden grey mullet (Liza aurata) and red mullet (Mullus barbatus) muscle were determined. Their spatial distribution throughout the Mar Menor lagoon was characterized considering 9 sampling areas and two different sampling periods, spring and autumn in 2010 for golden grey mullet and only one (autumn) for red mullet. PAHs and organochlorinated pollutants were extracted using specific Soxhlet procedures. After cleanup and purification steps the final extracts were analyzed by HPLC for PAHs, and by GC-MS for PCBs and OCPs. The higher concentrations of all pollutants were found close to main urban and port areas of this lagoon and in the influence area of El Albujón watercourse. PAHs concentrations (sum of 14 congeners) in both species varied between 1 and 20.7 g/kg w.w. being pyrene and phenanthrene the most abundant ones. p,p’DDE showed higher concentrations than PAHs in golden grey mullet (concentration range: 0.2-32.7 g/kg w.w.), specially close to the main navigation channel between this lagoon and the Mediterranean Sea.This work has been supported by the Spanish Inter-Ministerial Science and Technology Commission through ‘DECOMAR’ project (CICYT, CTM2008-01832) and by Seneca Foundation (Region of Murcia, Spain) through ‘BIOMARO’ project (15398/PI/10). Rubén Moreno-González wishes to thank the Spanish Ministry of Science and Innovation for the FPI grant (BES 2009-014713)
Coutaportla helgae (Rubiaceae), una especie nueva de Sinaloa, México
Background and Aims: During explorations in the outer limits of the Natural Protected Area Sierra de Tacuichamona, an endemic-rich area of Sinaloa, Mexico, a new species of Coutaportla (Rubiaceae) was discovered. This paper describes and illustrates Coutaportla helgae, provides an identification key, a distribution map, and discusses the morphological and geographic relationships with the rest of the species of the genus.
Methods: Botanical collections were made during 2021 and 2022, and 15 herbariums and digital databases were reviewed to compare with other species of the genus and to locate possible additional localities. A distribution map was prepared using the polygon of the Sierra Madre Occidental as a base.
Key results: Coutaportla helgae stands out from the rest of the species of the genus by having the smallest flowers of the group. It is morphologically related to C. lorenceana as they are the only species of the genus with subapical placentation and calyx lobes less than half the length of the fruit, but it differs in having smaller flowers, a shrubby habit and distribution in tropical deciduous forest.
Conclusions: With the present discovery, Coutaportla reaches four endemic species to Mexico and five overall, considering C. guatemalensis. Coutaportla helgae contributes new characteristics to the genus by having smaller flowers and growing at lower altitudes than the rest. Additionally, elements are provided to support the conservation of sites with high biodiversity and endemism such as the Sierra Tacuichamona.Antecedentes y Objetivos: Durante exploraciones en los límites exteriores del Área Natural Protegida Sierra de Tacuichamona, zona rica en endemismos de Sinaloa, México, se descubrió una especie nueva de Coutaportla (Rubiaceae). El objetivo del presente trabajo es describir e ilustrar a Coutaportla helgae, proveer una clave de identificación y un mapa de distribución, y discutir las relaciones morfológicas y geográficas con el resto de las especies del género.
Métodos: Se realizaron colectas botánicas durante 2021 y 2022, y se revisaron 15 herbarios y bases digitales para comparar con otras especies del género y localizar posibles localidades adicionales. Empleando el polígono de la Sierra Madre Occidental se elaboró un mapa de distribución.
Resultados clave: Coutaportla helgae se destaca del resto de especies del género al poseer las flores más pequeñas del grupo. Se relaciona morfológicamente con C. lorenceana al ser las únicas especies del género con placentación subapical y lóbulos del cáliz menor a la mitad del largo del fruto, pero se diferencia de esta por tener flores de menor tamaño, corolas blanco-púrpuras, hábito arbustivo y distribución en selva baja caducifolia.
Conclusiones: Con el presente descubrimiento, el género Coutaportla llega a cuatro especies endémicas de México y cinco en total, considerando a C. guatemalensis. Coutaportla helgae aporta nuevas características al género, pues posee las flores más pequeñas y crece a menores altitudes que el resto. Adicionalmente, se aportan elementos para apoyar la conservación de sitios altos en biodiversidad y endemismos como la Sierra Tacuichamona
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