Myocardial trabeculation in embryos of Scyliorhinus canicula (Elasmobranchii, Chondrichthyans)

Currently, three types of ventricular myoarchitecture are recognized in vertebrates, namely compact, spongy (trabeculated) and mixed myocardium. Mixed myocardium, which has been recently proposed as the primitive condition in gnathostomes, is composed of two myocardial layers: an inner trabeculated and an outer compact one. The trabeculation process has been studied in teleosts, showing exclusively spongy myocardium, and mammals and birds, characterized by a compact myocardial ventricular wall. In zebrafish, mouse and chicken embryos, the trabeculae develop as luminal myocardial ridges protruding into the lumen. In mammals and birds, further compactation of trabeculae leads to the formation of a compact layer. The potential mechanisms that may contribute to the formation of the ridges are under discussion and include myocardial proliferation, endocardial invagination, and bending of the entire myocardial layer. However, no description of the development of the mixed myocardium is available. To shed some light on this issue, we have studied the heart development of an elasmobranch species with mixed myocardium, the lesser spotted dogfish (Scyliorhinus canicula; Chondrichthyes), by means of histological and immunohistochemical techniques for light microscopy, semithin sections, scanning electron microscopy and transmission electron microscopy. Our results suggest that in the dogfish the intertrabecular spaces develop by connections between early intramyocardial spaces and the lumen of the ventricle through invaginations of the endocardial line. Chondrichthyans are the earliest diverged lineage of gnathostomes and, consequently, they have the most primitive cardiac design. Although chicken, mouse, and recently zebrafish have been considered powerful vertebrate models to study heart development, we propose that the trabeculation process in the dogfish is representative of the early steps of the ventricular morphogenesis in vertebrates.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Study supported by grant CGL2017-85090-P and CGL2014-52356-P (Ministerio de Economía y Competitividad), FPU15/03209 (Ministerio de Educación, Cultura y Deporte), FEDER, and Universidad de Málaga

Chamber specific expression of Myosin heavy chain 7b in the heart of vertebrates

In extant vertebrates, myosin heavy chain (MyHC) 6 and 7 are the main isoforms of atrial and ventricular myocardium respectively, whereas MyHC7b has been proposed to be an ancient cardiac isoform only expressed during embryonic development in modern species. In preliminary immunohistochemical studies of the heart of the lesser spotted dogfish (Scyliorhinus canicula; Chondrichthyes), we have observed that while MF20 labels homogeneously all the myocardium, A4.1025 labels the inflow cardiac segments (sinus venosus and atrium) but not the outflow segments (ventricle and conus arteriosus). In order to interpret these results, we have performed western and slot blots from samples of dogfish and hamster (Mesocricetus auratus) hearts, HPLC-ESI-MS/MS from dogfish samples, and immunohistochemistry in hearts of representative species of vertebrates, namely elasmobranchs, polypteriforms, acipenseriforms, teleosts and mammals, using MF20 and A4.1025 antibodies. Western and slot blot results confirmed the specificity of MF20 and A4.1025 for MyHC in dogfish, as well as their differential reactivity against different myocardial segments. HPLC-ESI-MS/MS using protein databases from Callorhinchus milii (Chondrichthyes) and Chordata revealed the presence of MyHC6 and 7 in all the dogfish myocardial segments, and of MyHC7b only in the outflow segments. Immunohistochemistry showed that while MF20 signals were homogeneous in all the myocardial segments of all the species studied, A4.1025 signals were restricted to the inflow myocardial segments in elasmobranchs, homogeneous in teleosts and acipenseriforms, and low in the ventricle of polypteriforms. It can be inferred that the A4.1025 antibody, as opposed to MF20, has a low affinity for MyHC7b, at least in the dogfish. In addition, we show that MyHC distribution in the cardiac chambers has changed during the evolution of gnathostomes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.Study supported by grants CGL2017-85090-P and CGL2014-52356-P (Ministerio de Economía y Competitividad), FPU15/03209 (Ministerio de Educación, Cultura y Deporte), contract UMAJI75 (Junta de Andalucía, European Social Found), FEDER and Universidad de Málaga

Los primeros humanos en América

Jornadas de Jóvenes en Investigación Arqueológica, JIA (3as : 5-7 de mayo 2010 : Universitat Autònoma de Barcelona). Sesión 4. Cultura material y transdisciplinariedad en la investigación arqueológica de Latinoamérica.La Prehistoria de America consta de 5 periodos, los tres primeros afectan propiamente a la Prehistoria, los restantes al desarrollo de las civilizaciones americanas. La etapa que ocupan el Paleolitico, Mesolitico, Neolitico y la Edad de los Metales en la Prehistoria universal, en America solo ocupa los periodos Paleoindios y un discutido periodo anterior, Pre-clovis. Los estudios actuales acerca del poblamiento se cimientan en los siguientes interrogantes: Como y por donde tuvo lugar?, Cuando tuvo lugar? y Quienes fueron los primeros colonizadores?. Desde finales del S.XX se ha creado una nueva corriente de investigacion, La Poblacion Temprana, que echa por tierra El Consenso Clovis, defendiendo un poblamiento anterior. Hay investigadores que consideran que la poblacion tuvo lugar hace 16.000-20.000 anos, para otros hace mas de 30.000 anos. En su explicacion exponemos los yacimientos mas distintivos y los argumentos que respaldan dicha teoria (arqueologicos, geneticos, linguisticos). Asi sostienen rutas alternativas para el ingreso de las poblaciones. En el caso de una poblacion independiente para America del sur, destacan las teorias que defienden una entrada desde el noroeste de Asia-Beringia-noroeste de America hacia el sur a traves de la costa. Y la que aboga por un trayecto Oceania-Polinesia-America del Sur. Aunque las teorias geneticas y linguisticas aun no habitan convenientemente con las tecnicas de investigacion arqueologicas, se han convertido en un importante elemento a la hora de discutir los temas que aqui tratamos.The America's prehistory is divided in five periods. Three affect, properly, to the prehistory, the others to the development of American Civilizations. The stages of universal prehistory (Paleolithic, Mesolithic, Neolithic and the Metal Age), for America corresponding to the paleoindian period, and a problematic precious period called Pre-Clovis. At the moment, the great subject of scientific interest makes reference to the occupation of the continent: How?, When?, Who?, and Where? At the end of XXth century, it appears a new current of work that puts in doubt the Clovis Consensus, proposing a previous occupation of continent. In this article are exposed the deposits and arguments that endorse this new theory. In the case of an independent population for South America, There are theories that defend an entry from the northwest of Asia-America-northwest Beringia southward along the coast. And advocating a path Oceania-Polynesia, South America.La Prehistoria d'America consta de 5 periodes, els tres primers afecten propiament a la Prehistoria, la resta al desenvolupament de les civilitzacions americanes. La etapa que ocupa el paleolitic, mesolitic, neolitic i l'edat dels metalls, a la Prehistoria universal, a America nomes ocupa els periodes paleoindis, i un discutit periode anterior anomenat Pre-Clovis. Els actuals estudis es basen en donar resposta els seguents interrogants al voltant de l'arribada dels primers pobladors del continent: com i per on va succeir?, quan va tenir lloc? I quins van ser els primers grups de poblament?. Des de finals de segle XX s'ha creat una nova corrent d'investigacio que deixa sense validesa el Consens Clovis, defensant un poblament previ. Hi ha investigadors que considerant que el poblament va tenir lloc fa 16.000 - 20.000 anys i altres fa mes de 30.000 anys. A aquesta explicacio s'exposaran els jaciments mes caracteristics i els arguments procedents de diferents arees d'investigacio que donen suport a aquesta nova corrent (arqueologia, genetica i linguistica). Sustentant d'aquesta manera vies alternatives per l'entrada de les poblacions. En el cas d'una poblacio independent per a l'area d'America del Sud, destaquen les teories que defensen una arribada des del nord-oest d'Asia - Beringia - nord-est d'America per la costa. I una altra que treballa amb la idea d'una arribada per Oceania - Polinesia - America del Sud. Malgrat que les teories genetiques i linguistiques a les que fan referencia moltes de les tesis esposades encara no habiten convenientment amb les tecniques d'investigacio arqueologica, s'han convertit en un important element alhora de discutir els temes aqui tractats

MYOCARDIAL STRUCTURE AND VASCULARIZATION OF THE HEART VENTRICLE IN HOLOCEPHALI: IMPLICATIONS FOR HEART EVOLUTION

El resumen aparece en el Program & Abstracts of the 10th International Congress of Vertebrate Morphology, Barcelona 2013. Anatomical Record, Volume 296, Special Feature — 1: P-075.It has been classically assumed that the ventricle of the primitive vertebrate heart is composed of spongy myocardium, supplied exclusively by oxygen-poor, luminal blood. This idea is on two facts: (1) extant agnathans have a spongy ventricular myocardium, and (2) in avian and mammalian embryos, the formation of trabeculated myocardium precedes the appearance of compact myocardium. Recently, it has been proposed that, like elasmobranchs, the early gnathostomes possess a fully vascularised ventricle composed of mixed myocardium. We tested this idea by studying the structure and vascularisation of the ventricular myocardium in four holocephalan species of the families Chimaeridae and Rhinochimaeridae. Chimaera monstrosa, Hidrolagus affinis and Harriotta raleighana have a spongy myocardium covered by a thin layer of cardiac muscle. In H. raleighana, the compacta is reduced to an extremely fine rim. In all three species there is a well-developed coronary artery system consisting of subepicardial vessels which give off branches that penetrate the myocardial trabeculae. Rhinochimaera atlantica has no compacta and its ventricular coronary artery system is reduced to subepicardial vessels that do not enter the spongy layer. This report is the first to show that in wild living vertebrates, a coronary artery system supplying the whole myocardium exists in the absence of a well-developed compacta, which supports experimental work that shows that myocardial cell proliferation and coronary vascular growth rely on genetically separated programs. We conclude that the mixed ventricular myocardium is primitive for chondrichthyans, and that the lack of compacta in some holocephalans is a derived character. Moreover our results support the hypotheses that the mixed myocardium is the primitive condition in gnathostomes, and that the absence of a compacta in different actinopterygian taxa is the result of its repeated loss during evolution.Proyecto CGL2010-16417/BOS; Fondos FEDE

Regional assessment of the Jenkinson-Collison weather types classification and observational uncertainty based on different reanalyses over the Mediterranean region

Ponencia presentada en: XII Congreso de la Asociación Española de Climatología celebrado en Santiago de Compostela entre el 19 y el 21 de octubre de 2022.[ES]El algoritmo de clasificación en tipos de tiempo de Jenkinson y Collison (JC-WT, Jenkinson and Collison 1977) es una técnica de agrupamiento usada para clasificar la circulación atmosférica en un número reducido de patrones de presión a nivel del mar. Esta metodología se basa en el cálculo de 6 parámetros intermedios relacionados con las características del flujo del viento. Este método ha tenido numerosas aplicaciones, siendo una de ellas la caracterización objetiva de la circulación atmosférica tanto a nivel global como regional, esencial para la evaluación de modelos climáticos y para su aplicabilidad en regionalización dinámica y estadística. La primera definición del método JC-WT centraba el estudio sobre las Islas Británicas pero puede ser, en principio, aplicado en latitudes medias-altas (Jones et al., 2013). El presente estudio examina la aplicabilidad la metodología JC-WT sobre la región Mediterránea y explora las diferencias entre cinco reanálisis a la hora de representar las características de los 27 JC-WT (sus frecuencias relativas y las probabilidades de transición entre tipos). Los resultados muestran diferencias importantes entre los distintos catálogos, sobre todo en verano. Además, se analizan estas diferencias entre reanálisis a nivel de los 6 parámetros intermedios de JC-WT con el fin de arrojar luz sobre la naturaleza sinóptica de las mismas. Estas discrepancias pueden comprometer la robustez de los estudios relacionados con la evaluación de modelos basada en procesos para esta región y desaconsejan el uso de un único reanálisis como referencia.[EN]The Jenkinson-Collison Weather Type (JC-WT; Jenkinson and Collison, 1977) classification is a clustering method used to classify the regional atmospheric circulation into a reduced number of typical recurrent sea-level pressure patterns. This methodology is a function of six parameters related to wind-flow characteristics. Originally developed for the British Isles, the method since then has seen many applications. One of its applications is serving for an objective characterization of either global or regional atmospheric circulation, a key feature for the assessment of climate models and their suitability for driving dynamical and statistical modeling experiments. Encouraged by the estimate that the JC-WT approach can in principle be applied to any mid-to-high latitude region (Jones et al, 2013), this study assesses the general application of JC-WT over the Mediterranean region, extending from the Iberian Peninsula in the west to the Levant in the east. We also explore to what extent the JC-WT features (such as frequencies of the 27 weather types and transition probabilities between pairs of types) obtained from five distinct reanalysis products agree with each other. Our results unveil important discrepancies among reanalyses, accentuated in summer. We furtherly explore these discrepancies deepening on the JC-WT base parameters in order to shed some light on the synoptic nature of these inconsistencies, that may compromise the robustness of circulation-based model assessments relying on a single reanalysis in these regions.The authors acknowledge funding from the R+D+i projects CORDyS (PID2020- 116595RB-I00) and ATLAS (PID2019-111481RB-I00), funded by MCIN/AEI/10.13039/501100011033. J.A.F. acknowledge funding from grant PRE2020-094728 funded by MCIN/AEI/10.13039/501100011033

Interannual variability of zooplankton biomass and structure in Ría de Vigo ( Galiza, NW Spain) and adjacent shelfwaters between 1994 and 2000.

Changes in zooplankton biomass and structure in relation to hidroclimatological indexes in Ría de Vigo and adjacent shelf waters are presented for the period 1994-2000. Zooplankton biomass showed an inverse relation with NAO, the Gulf Current and upwelling indexes. The interannual variations in zooplankton composition showed a gook correlation to changes in the hidroclimatological indexes. The presence of warm water species of Copepoda (i.e., Temora stylifera) and Cladocera (i.e., Evadne spinifera, Penilia avirostris) between 1996 and 1998 is reported. In the same years a high abundance of oceanic copepods, such as: Paraeuchaeta hebes, Centropages chierchiae, Oithona plumifera and copepodits of Calanus helgolandicus have been observed inside Ría de Vig

The Myosin Heavy Chain specific A4.1025 antibody discriminates different cardiac segments in ancient groups of gnathostomes: Morphological and evolutionary implications

El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 263.The pan-Myosin Heavy Chain (pan-MyHC) marker MF20 have been reported to show similar, homogeneous signal in the myocardial segments of the heart of teleosts and tetrapods. However, in an ongoing study of the myocardial structure of the dogfish (Scyliorhinus canicula; Chondrichthyes), we observed differential immunostaining of the cardiac segments using another pan-MyHC, the A4.1025 antibody. In order to investigate the relevance of this finding for better understanding of the morphology and evolution of the vertebrate heart, we performed immunohistochemistry, slot blot and western blot in several species of chondrichthyans, actinopterygians and mammals using the above mentioned antibodies. In the dogfish heart, A4.1025 and MF20 specifically recognized MyHC isoforms, although with different degree of affinity. MF20 reactivity was homogeneous and high in all the myocardial segments. However, A4.1025 reactivity was heterogeneous. It was high in the sinus venosus (external layer), atrium and atrioventricular region, low in the ventricle and conus arteriosus, and null in the internal layer of the sinus venosus. A heterogeneous pattern of A4.1025 immunoreactivity was also detected in two other elasmobranchs, a holocephalan, a polypteryform and an acipenseriform. In all of these species, MF20 immunoreactivity was homogeneous. In addition, both markers showed a homogeneous immunoreactivity pattern in teleosts and mammals. Our results indicate that in the hearts of ancient gnathostomes, in all of which a conspicuous conus arteriosus exists, one or more MyHC isoforms with low affinity for A4.1025 show segment-specific distributions. Thus, A4.1025 appears to be an appropriated marker to identify the cardiac segments and their boundaries. We propose that the segmentspecific distribution of MyHC isoforms may generate a particular type of myocardial contractility associated with the presence of a conus arteriosus.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

Anatomical, histochemical and immunohistochemical characterization of the outflow tract of ray hearts (Rajiformes; Chondrichthyes)

El resumen aparece en el Program & Abstracts of the 11th International Congress of Vertebrate Morphology, Washington DC 2016. Anatomical Record, Volume 299, Special Feature: 264.Recent work has shown that the cardiac outflow tract of sharks and chimaeras does not consist of a single myocardial component, the conus arteriosus, as classically accepted, but two, namely, the myocardial conus arteriosus and the non-myocardial bulbus arteriosus. However, the anatomical composition of the outflow tract of the batoid hearts remains unknown. The present study was designed to fill this gap. The material examined consisted of hearts of two species of rays, namely, the Mediterranean starry ray (Raja asterias) and sandy ray (Leucoraja circularis). They were studied using scanning electron microscopy, and histochemical and inmunohistochemical techniques. In both species, the outflow tract consists of two components, proximal and distal with regard to the ventricle. The proximal component is the conus arteriosus; it is characterized by the presence of compact myocardium in its wall and several transverse rows of pocket-shaped valves at its luminal side. Each valve consists of a leaflet and its supporting sinus. Histologically, the leaflet has two fibrosas, inner and outer, and a middle coat, the spongiosa. The distal component lacks myocardium. Its wall consists of smooth muscle cells, elastic fibers and collagen. Thus, it shows an arterial-like structure. However, it differs from the aorta because it is covered by the epicardium and crossed by coronary arteries. These findings indicate that the distal component is morphologically equivalent to the bulbus arteriosus of sharks and chimaeras. In contrast to foregoing descriptions, the valves of the first transverse row are distally anchored to the bulbus arteriosus and not to the ventral aorta. Our findings give added support to the notion that presence of a bulbus arteriosus at the arterial pole of the heart is common to all chondrichtyans, and not an apomorphy of actinopterygians as classically thought.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. CGL2014-52356-P, CEIMAR, BIO 203, FEDE

Sustainable alkali binders: Waste activating wastes

Alkaline binders usually requires two main components, namely the solid precursor, rich in alumina and silica (preferably in an amorphous state); and the activator solution, based on an alkali metal (usually sodium or potassium). The role of the precursor is commonly assumed by a residue, usually fly ash or blast furnace slag with significant economic and environmental benefits. However the activator is frequently prepared with first grade commercial reagents (usually sodium or potassium hydroxide and sodium or potassium silicate), which significantly increases the financial costs and severely dilutes the environmental initial advantages, due to the high CO2-eq released during the production of the reagents. These drawbacks associated with the activator severely hinder the wide spreading of this technology severely making the development of low cost activators a major research target. Therefore, a strong expectation regarding the application of industrial residues as the main (or even the sole) constituent of the activators – and not just as the precursor – is rapidly growing. The aim of the present paper is thus to analyse the potential application of some by-products, in this case from the aluminium foundry industry, as the alkali activator of two different precursors: fly ash type F (FA) and blast furnace slag (BFS)

Mesozooplankton from Ría de Vigo (NW Spain) and its adjacent shelf between 1995 and 2003

The mesozooplankton (200 μm to 2 mm) community from monthly samples collected at two stations in Ría de Vigo (39 m) and its adjacent shelf (97 m) between 1995-2003 is described. The mesozooplankton was dominated by copepods. Inside the Ría, meroplankton (larvae of gasteropods, lamelibranchiae, echinodermate and cirripids nauplii) and other holoplanktonic organisms, such as apendicularia, cladocera, siphonophora and medusae, were also well represented. The copepod group inside the Ría was dominated by Acartia clausi, juveniles of Calanus helgolandicus, Paracalanus parvus, Pseudocalanus elongatus, Temora longicornis, Oithona plumifera, Oncaea media, Euterpina acutifrons and copepodites of Centropages spp. In the offshore station, dominant copepods species were the same than inshore together with other oceanic species, such as Paraeuchaeta hebes, Calanoides carinatus and Aetideus armatus. Biomass values within Ría de Vigo ranged between 2 and 151 mg dry weight /m3 and between 2 and 314 mg dry weight /m3 in the offshore station. Abundance ranged between 149 ind/m in January 1995 and 41814 ind/m3 in August of 2003 in the inner station, and between 22 ind/m3 in January 1996 and 93410 ind/m3 in May 1999 in the outer station. The most outstanding events were the high levels of the Mediterranean copepod Temora stylifera, usually rare in Galician waters recorded in the area in 1997 and 1998, and the increased levels of cirripid larvae observed inside the Ría