Is the bulbus arteriosus of fish homologous to the mamalian intrapericardial thoracic arteries?

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-089.Two major findings have significantly improved our understanding of the embryology and evolution of the arterial pole of the vertebrate heart (APVH): 1) a new embryonic presumptive cardiac tissue, named second heart field (SHF), forms the myocardium of the outflow tract, and the walls of the ascending aorta (AA) and the pulmonary trunk (PT) in mammals and birds; 2) the bulbus arteriosus (BA), previously thought to be an actinopterygian apomorphy, is present in all basal Vertebrates, and probably derives from the SHF. We hypothesized that the intrapericardial portions of the AA and the PT of mammals are homologous to the BA of basal vertebrates. To test this, we performed 1) a literature review of the anatomy and embryology of the APVH; 2) novel anatomical, histomorphological, and embryological analyses of the APVH, comparing basal (Galeus atlanticus), with apical (Mus musculus and Mesocricetus auratus) vertrebrates. Evidence obtained: 1) Anatomically, BA, AA, and PT are muscular tubes into the pericardial cavity, which connect the distal myocardial outflow tracts with the aortic arch system. Coronary arteries run through or originate at these anatomical structures; 2) Histologically, BA, AA, and PT show an inner layer of endothelium covered by circumferentially oriented smooth muscle cells, collagen fibers, and lamellar elastin. The histomorphological differences between the BA and the ventral aorta parallel those between intrapericardial and extrapericardial great arteries; 3) Embryologically, BA, AA, and PT are composed of smooth muscle cells derived from the SHF. They show a similar mechanism of development: incorporation of SHF‐derived cells into the pericardial cavity, and distal‐to‐proximal differentiation into an elastogenic cell linage. In conclusion, anatomical, histological and embryological evidence supports the hypothesis that SHF is a developmental unit responsible for the formation of the APVH. The BA and the intrapericardial portions of the great arteries must be considered homologous structures.Proyecto P10-CTS-6068 (Junta de Andalucía); proyecto CGL-16417 (Ministerio de Ciencia e Innovación); Fondos FEDER

Performance optimization in switched reluctance motor drives

In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. A prototype machine has been developed as very attractive design for a steering electric motor, both from a cost and size perspective. A fourphase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design

Incidence and type of bicuspid aortic valve in two model species

Incidence and type of bicuspid aortic valve in two model species. MC Fernández 1,2, A López-García 1,2, MT Soto 1, AC Durán 1,2 and B Fernández 1,2. 1 Department of Animal Biology, Faculty of Science, University of Málaga, Spain. 2 Biomedical Research Institute of Málaga (IBIMA), University of Málaga, Spain. Bicuspid aortic valve (BAV) is the most frequent human congenital cardiac malformation, with an incidence of 1–2% worldwide. Two morphological types exist: type A (incidence 0.75–1.25%) and type B (incidence 0.25–0.5%), each with a distinct aetiology and natural history. Currently, ten animal models of BAV have been described in two different rodent species: one spontaneous Syrian hamster (Mesocricetus auratus) model of BAV type A and nine mutant laboratory mouse (Mus musculus) models of BAV type B. It remains to be elucidated whether the mutations leading to BAV in these models are typespecific or whether there are inter-specific differences regarding the type of BAV that hamsters, mice and humans may develop. To solve this issue, we have characterized the incidence and types of BAVs in four inbred, two outbred and two hybrid lines of Syrian hamsters (n=4,340) and in three inbred, three outbred and one hybrid lines of laboratory mice (n=1,661) by means of stereomicroscopy and scanning electron microscopy. In addition, we have reviewed and calculated the incidence and type of BAVs in the published papers dealing with this anomaly in mice. Our results indicate that the Syrian hamster develops BAVs type A and B including a variety of morphologies comparable to those of humans, whereas the mouse develops only BAVs type B with a short spectrum of valve morphologies. Thus, inter-specific differences between human and mouse aortic valves must be taken into consideration when studying valve disease in murine models. This work was supported by P10-CTS-6068.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. P10-CTS-6068

Risk tasking behaviour and ownership in the banking industry: the Spanish evidence

This paper analyses the determinant of risk_taking in the Spanish financial intermediaries with special emphasis on the ownership structure and size of the different entities. On the one hand, the soecific legal configuration of Spanish Savings banks may lead them to differ from Commercial banks in their risk behaviour. In particular, they may make riskier investments. Nevertheless,other theories indicate that greater stockholder control in Commercial banks may induce them towards greater risk_taking in certain situations. In this paper we test these hypotheses with a dynamic pañel data model (1993_2000) for Spanish Commercial banks and Savings banks. We analyse whether differences in risk behaviour are related to different ownership structures or to other factors such as the size of the entity.Commercial banks, Savings banks, Corporate control, Ownership structure, Bank risk_taking

On the generating function of weight multiplicities for the representations of the Lie algebra C2C_2

We use the generating function of the characters of $C_2$ to obtain a generating function for the multiplicities of the weights entering in the irreducible representations of that simple Lie algebra. From this generating function we derive some recurrence relations among the multiplicities and a simple graphical recipe to compute them.Comment: arXiv admin note: text overlap with arXiv:1304.720

Paleoecología y biocronología mediante el estudio de los roedores del Pleistoceno Superior-Holoceno de la cueva del Toll (Moià, Cataluña, NE de la península Ibérica)

El presente trabajo muestra los resultados del análisis paleoecológico, paleoambiental y bioestratigráfico del estudio de los restos de roedores obtenidos mediante lavado y tamizado de los sedimentos pertenecientes a los niveles 2-4 del Sector Entrada de la cueva del Toll (Moià, Cataluña, NE de la península Ibérica), integrada dentro del complejo kárstico de las Coves del Toll. Hasta la fecha se han recuperado un total de 216 restos de roedores, todos ellos identificados a nivel de especie, distinguiéndose 10 taxones. De los resultados biocronológicos se deduce una cronología de Pleistoceno Superior final e inicios del Holoceno (13 ka BP) y el Nivel 2, posiblemente holoceno (Palaeoecology and biochoronology through the analyzed Late Pleistocene-Holocene rodents of the Toll cave (Moià, Catalonia, NE of the Iberian Peninsula) This paper presents the chronological, environmental and climatic data obtained when analyzing the rodent remains collected from the water-screened sediments from levels 2-4 of the “Sector Entrada” in the Toll cave (Moià, Catalonia, NE Iberian Peninsula), one of the cavities belonging to the karstic system called “Coves del Toll” (Toll Caves). From these levels, a total of 216 rodent remains corresponding to 10 rodent species has been recovered. The biochronological results show a latest Pleistocene-Holocene chronology ( 13 ky BP), and Level 2 probably holocene (< 13 ky BP). The palaeoclimatic and palaeoenvironmental data indicate an open wet forest with lower temperatures and higher precipitation than nowadays for this region. Level 3 could be correlated with the Last Glacial Maximum, while Level 2 may belong to the Preboreal period. From the comparison with data obtained in other sites with a similar chronology in the northeast of the Iberian Peninsula, two transitional phases can be inferred for this period. The comparison with the Teixoneres cave studies allows obtaining the climatic and environmental evolution of the surroundings of the Toll Caves between the Middle Paleolithic and the Upper Paleolithic/Neolithic. It can be asserted that both neanderthals and anatomically modern humans lived under similar climatic and environmental conditions.El presente trabajo muestra los resultados del análisis paleoecológico, paleoambiental y bioestratigráfico del estudio de los restos de roedores obtenidos mediante lavado y tamizado de los sedimentos pertenecientes a los niveles 2-4 del Sector Entrada de la cueva del Toll (Moià, Cataluña, NE de la península Ibérica), integrada dentro del complejo kárstico de las Coves del Toll. Hasta la fecha se han recuperado un total de 216 restos de roedores, todos ellos identificados a nivel de especie, distinguiéndose 10 taxones. De los resultados biocronológicos se deduce una cronología de Pleistoceno Superior final e inicios del Holoceno (13 ka BP) y el Nivel 2, posiblemente holoceno