Search results for " Stasis"
showing 10 items of 16 documents
Agenesis of the renal segment of inferior vena cava associated with venous stasis.
2010
Congenital anomalies of the inferior vena cava is an extremely rare vascular anomaly with controversial pathogenesis. Anomalies of the inferior vena cava (IVC) are present in 0.3% to 0.5% of otherwise healthy individual and in 0.6% to 2% of patients with other cardiovascular defects. The phenomenon of absence of the IVC has been described in a variety of ways such as absence, agenesis, anomalous, and interruption of a particular segment ([infra] hepatic, pre-renal, renal, or infrarenal) of the IVC. We describe a 42-year-old man with chronic venous insufficiency, without DVT, caused by congenital absence of renal segment of the IVC
Taxonomic flux as a measure of evolutionary turnover
2021
We introduce a new metric, "taxonomic flux", to quantify evolutionary trends both within and across taxonomic boundaries. This metric is normalized, which reduces the effect of sample size disparity between biologic groups and time intervals. Furthermore, this methodology considers stratigraphic range data as a whole, and measures relative growth or decline of diversity values as they deviate from system stability. Such trends may yield key information relating to evolutionary processes and forcing functions, especially if these trends are correlative within particular taxa or niche occupancy. Thus far, scientists and researchers have been stymied by absolute values derived from unequal dat…
The force interpretation of evolutionary theory: scope and limits
2016
La teoría evolutiva suele entenderse como una teoría causal donde las causas principales del cambio evolutivo son identificadas con la selección natural, la deriva genética, la mutación y la migración. Siguiendo este razonamiento, muchos biólogos y filósofos de la biología han estructurado la teoría evolutiva de forma análoga a la mecánica newtoniana, entendiendo la teoría evolutiva como una teoría de fuerzas. El punto clave en el que se sustenta la analogía, es que la estructura de la mecánica newtoniana permite identificar los elementos causales del sistema de interés. De esta manera, la teoría evolutiva encuentra una útil imagen explicativa del fenómeno evolutivo, estructurándose como un…
Endosymbiont communities in Bemisia tabaci: a metagenomic approach
2014
Este trabajo es parte de un programa de investigación que tiene como objetivo dilucidar la evolución de las bacterias endosimbiontes utilizando los consorcios insecto-bacteria como modelo. Los diferentes estudios realizados sobre los insectos y sus bacterias endosimbiontes han arrojado luz sobre los cambios ocurridos tras la adquisición de una forma de vida intracelular, así cómo la interacción entre diferentes endosimbiontes formando comunidades endosimbioticas. Dos son los objetivos principales de este trabajo. El primera (capítulos “Portiera y su socio Hamiltonella” y “El tercer pasajero: Cardinium cBtQ1)” trata de analizar y describir las relaciones de la comunidad endosimbiótica en B. …
A geographical note about the journey
2022
This paper summarizes the contents of the in print monographic volume entitled About the journey. Stasis, chiasmus and interruptions. A geography essay. It aims at being part of the epistemological debate on the role of the journey intended as a complex action through which relationships between man and space are strengthened and the fundamental cognitive processes are activated. In the first chapter, we want to foster a consideration on the tripartite scan that has the journey as the terminal outcome: stasis, trigger, experience. The paper has its roots in the international and national debates of New Cultural Geography, an essential theoretical prerequisite for setting up a theoretically …
About the journey. Stasis, chiasmus and interruptions A geography essay
2022
The journey is a very stimulating function to read the congeries of relationships that intersect and signify the bonds of men with places. A device that activates, in Geography, different heuristic perspectives. The first chapter then aims at being part of the epistemological debate on the function of journey intended as a complex action through which relationships between man and space are strengthened and the fundamental cognitive processes are activated. In particular, in the first chapter, we want to foster a consideration on the tripartite scan that has the terminal outcome in the journey: stasis, trigger, experience. The second chapter then follows some literary suggestions to try to …
Retroauricular skin: a flaps bank for ear reconstruction.
2006
Retroauricular skin: a flaps bank for ear reconstruction. Cordova A, D'Arpa S, Pirrello R, Giambona C, Moschella F. Source Cattedra di Chirurgia Plastica e Ricostruttiva, Dipartimento di Discipline Chirurgiche ed Oncologiche, Università degli Studi di Palermo, Via del Vespro 129, 90127 - Palermo, Italy. adriana.cordova@excite.com Abstract BACKGROUND: The retroauricular skin has always been given much attention by the reconstructive surgeon for ear and face reconstruction because it is richly vascularised, as many anatomical investigations show, it is hidden behind the ear, its skin is very similar to that of ear and face. All these reasons make it an ideal donor site for ear reconstruction.…
Genome Evolution in the Primary Endosymbiont of Whiteflies Sheds Light on Their Divergence
2015
International audience; Hemipteran insects are well-known in their ability to establish symbiotic relationships with bacteria. Among them, heteropteran insects present an array of symbiotic systems, ranging from the most common gut crypt symbiosis to the more restricted bacteriome-associated endosymbiosis, which have only been detected in members of the superfamily Lygaeoidea and the family Cimicidae so far. Genomic data of heteropteran endosymbionts are scarce and have merely been analyzed from the Wolbachia endosymbiont in bed bug and a few gut crypt-associated symbionts in pentatomoid bugs. In this study, we present the first detailed genomic analysis of a bacteriome-associated endosymbi…
Intracapillary HbO2 Saturation in Tumor Tissue of DS-Carcinosarcoma During Normoxia
1978
Investigations on solid tumor tissue have shown that O2 uptake by cancer cells depends largely on the supply conditions. The absence of sufficient neovascularization and a general rarefaction of the terminal vascular bed during tumor growth as well as reduced and inhcmogeneous blood flew due to vascular stasis in neoplastic tissue prevent normal functions of the terminal vascular bed. In some areas of the tumor circulating blood is not visible despite the intactness of vessels. Stasis occurs since lacuna-like, sinusoidal and cystiform blood vessels cannot be drained completely because ‘tissue-pressure’ due to continuous cell proliferation can prevent efficient circulation. Thrombosis follow…
Der Einflu� einer ven�sen Stauung im Kopfbereich auf die Wasser- und Elektrolytausscheidung von Ratten
1960
1. Salt and water retention can be produced in rats by compression in the neck region or by ligature of the jugular veins.