Inferring muscle functional roles of the ostrich pelvic limb during walking and running using computer optimization

Owing to their cursorial background, ostriches (Struthio camelus) walk and run with high metabolic economy, can reach very fast running speeds and quickly execute cutting manoeuvres. These capabilities are believed to be a result of their ability to coordinate muscles to take advantage of specialized passive limb structures. This study aimed to infer the functional roles of ostrich pelvic limb muscles during gait. Existing gait data were combined with a newly developed musculoskeletal model to generate simulations of ostrich walking and running that predict muscle excitations, force and mechanical work. Consistent with previous avian electromyography studies, predicted excitation patterns showed that individual muscles tended to be excited primarily during only stance or swing. Work and force estimates show that ostrich gaits are partially hip-driven with the bi-articular hip–knee muscles driving stance mechanics. Conversely, the knee extensors acted as brakes, absorbing energy. The digital extensors generated large amounts of both negative and positive mechanical work, with increased magnitudes during running, providing further evidence that ostriches make extensive use of tendinous elastic energy storage to improve economy. The simulations also highlight the need to carefully consider non-muscular soft tissues that may play a role in ostrich gait

An overview of education and religious content teaching within the Slovenian education system

Šolstvo je eden izmed ključnih elementov, na katerem stoji naša družba. V preteklosti se je sistem šolanja oblikoval in urejal postopoma, skladno z razvojem posameznih držav. Poseben pomen je šolstvo pridobilo, ko ga je pod svoje okrilje vzela državna oblast in začela urejati njegovo organizacijo in vsebino. Avtor nam predstavi ključne mejnike, ki so, gledano z vidika zakonodaje, vplivali na razvoj šolstva pri nas. Pod drobnogled vzame verski pouk in opredeljuje, na podlagi katerih zakonov in odlokov sta se v preteklosti njegov pomen in vsebina spreminjala. Prvoten namen verskega pouka je bil v vzgoji državljanov, vendar se je poudarek skozi zgodovino spreminjal. Veliko je bilo odvisno od zahtev zakonodajalca, ki je sčasoma vedno odločneje posegal v ureditev in vsebino celotnega šolstva, tudi na področje verske vzgoje in izobraževanja. Posebnost naših krajev je, da smo bili Slovenci skoraj 50 let pod močnim vplivom komunizma, ki je radikalno umaknil vsakršno versko vzgojo iz šolskega sistema, kar se pozna še danes. Izgradnja pluralne družbe, ki bo enako obravnavala verne in neverne, je izziv, ki si ga moramo postaviti visoko na prioritetno mesto, da nam bo v času migracij in trkov različnih kultur uspelo ohraniti svojo identiteto ter hkrati v polnosti spoštovati druge.Education is one of the key elements on which our society stands. In the past, the school system has been designed and regulated gradually, in line with the development of individual countries. Education gained special significance when the state authorities took it under their wing and began to regulate its organization and content. The author presents the key milestones that, from the point of view of legislation, have influenced the development of education in Slovenia. It takes a closer look at religious studies and identifies which laws and ordinances have changed its meaning and content in the past. The original purpose of religious studies was in upbringing citizens, but the emphasis has changed throughout history. Much depended on the requirements of the legislator, who over time increasingly resolutely intervened in the regulation and content of the entire school system, including the field of religious education. The peculiarity of our places is that we, Slovenes, have been under the strong influence of communism for almost 50 years, which radically removed any religious education from the school system, which is still seen today. Building a plural society that treats believers and non-believers alike is a challenge that we must prioritize in order to maintain our identity during migrations and clashes of different cultures, while fully respecting others

The Vascularization of the Digestive Tract Studied by Scanning Electron Microscopy with Special Emphasis on the Teeth, Esophagus, Stomach, Small and Large Intestine, Pancreas, and Liver

The periodontal vessels in adult rats show a ladder-like pattern; in guinea pigs molars, by contrast, they present a honey-comb pattern. The vascular architecture in human teeth seems to be similar to that of rabbits. In guinea pigs, rats, rabbits and humans esophagus circumferential vessels give off perforating vessels. In human esophagus the number and diameter of the vessels in the submucous venous plexus decrease from proximal to distal. In the stomach the subepithelial capillary network shows a honey-comb pattern reflecting the arrangement of the gastric pits. A local portal system between the gastric glands and the surface mucosal cells for the transport of HCO3- ions has been suggested. In the small intestine of humans and rabbits the existence of a dual blood supply of the villus has meanwhile been established. It consists of pericryptal capillaries for the lower portion of the villus (tuft pattern) and a direct arterial supply up to the villus tip (fountain pattern). The colonic microvasculature closely resembles that of the stomach. In the pancreas the insulo-acinar portal system is physiologically significant in that it connects the venules draining the islets with the acini. Venous sphincters in the vascular system of the exocrine pancreas of the rat are of particular functional importance. The hepatic sinusoids are supplied both by the hepatic artery and the branches of the portal vein. The peribiliary plexus is supplied by the afferent vessels of the hepatic artery, the efferent vessels drain the plexus either into the sinusoids or into the lobular vein

The Microvasculature of the Guinea Pig Ureter. A Scanning Electron Microscopic Investigation

In 24 albinotic guinea pigs (Cavia porcellus) the gross vasculature and the microvascular architecture of the ureter were studied by light microscopy of tissue blocks and by scanning electron microscopy of vascular casts. The guinea pig ureter is supplied by the renal artery proximally, by the aorta and the internal iliac artery in its mid-segment, and by the uterine and prostatic as well as by the vesical arteries distally. The main arterial trunks run alongside the ureter before they branch to send perforating arterioles to the muscular coat and the mucosal lining. The draining venules are found on both sides of the ureter and form transverse anastomoses. Communications between the arterioles are also located on both sides, but longitudinally arranged. The capillary network of the mucosal lining shows an undulating pattern with tortuous vessels and lies just below the epithelium. The muscular coat and the adventitia have no prominent capillaries of their own. Large arteries are embedded in the adventitia, large veins in the lamina propria. In analogy to human anatomy the vascular arrangement found suggests that, if the ureters are excised in transplant surgery, a lateral incision should be used for the abdominal portion, while the pelvic portion is best approached by a medial incision

Esophageal Vasculature in the Guinea Pig: A Scanning Electron Microscope Study of Vascular Corrosion Casts

The esophageal vascularization of adult male and female albinotic Guinea pigs (Cavia porcellus) is studied by means of light microscopically evaluated serial sections and by scanning electron microscopy (SEM) of vascular corrosion casts. Bronchoesophageal artery (cervical portion), direct branches of tha aorta, recurrent branches of the intercostal arteries (thoracic portion) as well as of the left gastric artery (abdominal portion) supply the esophagus; internal jugular vein, inferior thyroid vein (cervical portion), azygos vein, intercostal veins (thoracic portion) and portal vein, gastroepiploic vein and cranial pancreatoduodenal vein (abdominal portion) drain it. Longitudinally arranged arterioles, venules and capillaries lying at the level of the lamina propria of the esophageal mucosa around the whole circumference of the organ are the most striking vascular features, whereby the venules are considered as those vessels from which esophageal varices arise under pathological conditions

Comparative functional genomics and artificial neural networks for the study of the evolution of cis-regulation

Programa de Doctorado en Biotecnología, Ingeniería y Tecnología QuímicaLínea de Investigación: Biología del DesarrolloClave Programa: DBICódigo Línea: 9La regulación transcripcional es el primer y quizás más importante paso de la regulación génica, una compleja serie de dinámicas que, en última instancia, controla qué cantidad de producto génico se expresará en una célula en cada momento. Los distintos niveles de actividad transcripcional y la acumulación diferencial de tránscritos resultante conducen a la diferenciación celular, la piedra angular de la vida multicelular. La transcripción se regula mediante la interacción de distintas proteínas (factores en trans) que se unen al ADN en sitios específicos del genoma (elementos cis). Las primeras llamadas Factores de Trancripción y a los segundos Elementos Reguladores en Cis (TFs y CREs respectivamente, por sus siglas en inglés). Estudiada desde la perspectiva de la evolución genómica, la regulación transcripcional es excepcionalmente interesante. Los CREs pueden evolucionar con relativa rapidez y se considera que sus cambios son el motor principal de la evolución morfológica en animales. Así, una pequeña modificación que afecte a un sitio de unión de un TF durante el desarrollo embrionario podría dar lugar a efectos en cascada y alterar profundamente la forma del organismo. En este trabajo, nos enfrentamos a dos aspectos de este amplio campo de investigación. Para la primera parte del trabajo, investigaremos la evolución de la regulación en cis en el origen de los vertebrados. Para ello, empleamos el exhaustivo conjunto de datos genómicos, transcriptómicos y epigenómicos que generamos para el anfioxo mediterráneo (Branchiostoma lanceolatum). El anfioxo es un organismo ideal para tales investigaciones ya que, por varias razones tanto genómicas como morfológicas, se puede considerar que es el linaje existente que guarda una mayor similitud con el ancestro común de todos los cordados. Contrapondremos los datos de anfioxo con la igualmente extensa colección de datos que hemos generado para el pez cebra, así como con datos adicionales de peces medaka y de ratón. Para la segunda parte, nos centramos en el problema de identificar sitios de unión de TFs en el genoma. Aplicamos un enfoque matemático de vanguardia, una red de convolución o red neuronal (NN) que integra al mismo tiempo información de secuencia genómica con información de señal de ATACseq, para predecir con precisión sitios reales de unión de TFs usando únicamente experimentos de ATACseq. En este trabajo presentaremos nuestra NN y los resultados obtenidos al compararla con otras técnicas actuales. Estos resultados muestran que nuestro método puede resultar muy valioso en análisis genómicos actuales, ya que permite reemplazar con un solo experimento de ATACseq múltiples experimentos de ChIPseq, reduciendo de manera muy significativa los costes y el tiempo de los experimentos de secuenciación. Además, nuestra NN puede ser entrenada primero en una especie con datos de ChIPseq previamente disponibles y usarse después en otras especies diferentes, un enfoque que es particularmente atractivo para realizar comparaciones evolutivas, especialmente en el caso de nuevos organismos modelo.Universidad Pablo de Olavide de Sevilla. Centro de Estudios de PosgradoPostprin

Sphincters in the Rat Pulmonary Veins. Comparison of Scanning Electron and Transmission Electron Microscopic Studies

The microvasculature of the rat lung was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of vascular corrosion casts and tissue sections. Particular emphasis was placed on postcapillary venules, pulmonary venules and small pulmonary veins (small interlobular veins). Casts of lung capillaries appeared inconspicuous with smooth surface. On the casts of pulmonary venules and small pulmonary veins, by contrast, series of narrow annular constrictions, present at regular distances of 20-25 μm, were seen. These constrictions may be drastic, narrowing down the caliber of the vessel up to 50%. In the constrictions the marks of circularly running tubular structures were seen and were interpreted as being caused by circular bands of smooth muscle cells. Tissue sections of the corresponding vascular wall showed the presence of single or grouped smooth muscle cells which regularly formed myoendothelial junctions. These smooth muscle cells are interpreted as sphincters, responsible for the constrictions seen on cast preparations. Axon terminals were not found in spatial relationship to these sphincters. It is suggested that the described venous sphincters are governed by blood-borne and/or endothelium-derived substances and may significantly influence the blood flow

The Complexity of Cluster Vertex Splitting and Company

Clustering a graph when the clusters can overlap can be seen from three different angles: We may look for cliques that cover the edges of the graph, we may look to add or delete few edges to uncover the cluster structure, or we may split vertices to separate the clusters from each other. Splitting a vertex $v$ means to remove it and to add two new copies of $v$ and to make each previous neighbor of $v$ adjacent with at least one of the copies. In this work, we study the underlying computational problems regarding the three angles to overlapping clusterings, in particular when the overlap is small. We show that the above-mentioned covering problem, which also has been independently studied in different contexts,is NP-complete. Based on a previous so-called critical-clique lemma, we leverage our hardness result to show that Cluster Editing with Vertex Splitting is also NP-complete, resolving an open question by Abu-Khzam et al. [ISCO 2018]. We notice, however, that the proof of the critical-clique lemma is flawed and we give a counterexample. Our hardness result also holds under a version of the critical-clique lemma to which we currently do not have a counterexample. On the positive side, we show that Cluster Vertex Splitting admits a vertex-linear problem kernel with respect to the number of splits.Comment: 30 pages, 9 figure

Diario de noticias sobresalientes en Lima y noticias de Europa (1700-1711), Volumen 2 (1706-1711)

En este segundo volumen ofrecemos la edición de los años finales del Diario de noticias sobresalientes en Lima y Noticias de Europa (1700-1711), periódico impreso por Joseph de Contreras y Alvarado. El período aquí cubierto va de enero de 1706 a diciembre de 1711, y corresponde a los años más críticos de la Guerra de Sucesión española y, en el virreinato del Perú, a los gobiernos del marqués de Castell dos Rius y, parcialmente, del arzobispo Diego Ladrón de Guevara. Esta serie única de pliegos sueltos muestra la historia de las élites del virreinato del Perú, con sus poderosos comerciantes, y la vida cotidiana de la ciudad, con sus jerarquías y devociones populares, y revela la importancia del taller editorial e imprenta de Lima como un centro difusor de las noticias en la Monarquía Hispánica. La edición se complementa con un nuevo estudio preliminar y notas al texto sobre léxico, referentes culturales y fuentes noticiosas