Ernst Haeckel's Embryological Illustrations
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Sahel Journal of Veterinary Sciences
Original Article Sahel Journal of Veterinary Sciences Article History Received: 4th March, 2020 Sahel J. Vet. Sci. Vol. 17, No. 2, pp. 19-25 (2020) Revised: 3rd June, 2020 Copyright © 2020 Faculty of Veterinary Medicine, University of Maiduguri Accepted: 7th June, 2020 All rights reserved Published: 30th June, 2020 Structure of the Leydig Cell in the African Sideneck Turtle (Pelusios castaneus) Olukole, S. G. and Oke, B. O. Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria. * Author for Correspondence: [email protected]; +2348033574752 Abstract The African sideneck turtle (Pelusios castaneus) is a freshwater turtle of West African origin used in traditional medicine with little consumption as meat. There have been documentations on the reproductive biology of the turtle with no report on the structure of the Leydig cell of the animal. We described the structure of the Leydig cell of the adult African sideneck turtle using histology, microstereology and transmission electron microscopy. The Leydig cell of the African sideneck turtle were elliptical in shape when found proximal to blood vessels and elongated at other points within the testicular interstitium. Leydig cells occurred in cords or clusters of varying sizes and numbers (3-5 cells) that appear to be random in distribution possessing round to ovoid nuclei containing small amount of peripherally disposed heterochromatin with prominent nucleoli. The seminiferous tubules of the turtle occupied about 85% of the total testicular parenchyma while the interstitium occupied 15% of it. Of this 15%, the Leydig cell occupied about 10% while the stromal elements, inclusive of blood vessels occupied the remaining 5%. -
Proceedings of the Seventh European Conference on Echinoderms, Göttingen, Germany, 2–9 October 2010
Zoosymposia 7: vii–ix (2012) ISSN 1178-9905 (print edition) www.mapress.com/zoosymposia/ ZOOSYMPOSIA Copyright © 2012 · Magnolia Press ISSN 1178-9913 (online edition) Preface—7th European Conference on Echinoderms MIKE REICH1,2 & JOACHIM REITNER1,2,3 1 Georg-August University of Göttingen, Geoscience Museum & Geopark, Göttingen, Germany; E-mail: [email protected] 2 Georg-August University of Göttingen, Geoscience Centre, Department of Geobiology, Göttingen, Germany 3 Georg-August University of Göttingen, Courant Research Centre Geobiology, Göttingen, Germany *In: Kroh, A. & Reich, M. (Eds.) Echinoderm Research 2010: Proceedings of the Seventh European Conference on Echinoderms, Göttingen, Germany, 2–9 October 2010. Zoosymposia, 7, xii + 316 pp. Since the pioneering meeting in 1979 in Brussels, the European echinoderm community has cele- brated advances in echinoderm science, biology and palaeontology in what has now become a regular conference series (see Ziegler & Kroh 2012, p. 1–24 of this volume). This reflects the interest of the scientific community in the multidisciplinary field of echinoderm research between biology, palae- ontology, physiology, fisheries, aquaculture, medicine and others. The 7th European Conference on Echinoderms (ECE) was held on October 2–9, 2010 (Fig. 1) in Germany, and was hosted by the Georg-August University of Göttingen. The Göttingen University has a long tradition in echinoderm research. A vast number of naturalists, zoologists, palaeontologists, and collectors, like Pehr Forsskål (1732–1769), Peter Simon -
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Manuscript version: Author’s Accepted Manuscript The version presented in WRAP is the author’s accepted manuscript and may differ from the published version or Version of Record. Persistent WRAP URL: http://wrap.warwick.ac.uk/113725 How to cite: Please refer to published version for the most recent bibliographic citation information. If a published version is known of, the repository item page linked to above, will contain details on accessing it. Copyright and reuse: The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available. Copies of full items can be used for personal research or study, educational, or not-for-profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher’s statement: Please refer to the repository item page, publisher’s statement section, for further information. For more information, please contact the WRAP Team at: [email protected]. warwick.ac.uk/lib-publications Systematicity in Kant’s third Critique Andrew Cooper – [email protected] Penultimate draft – please refer to published version: https://www.pdcnet.org/idstudies/content/idstudies_2019_0999_1_14_83 Idealistic Studies 47(3), 2019 Abstract: Kant’s Critique of the Power of Judgment is often interpreted in light of its initial reception. -
The Physiology and Immunology of the Endocrine Testis
tì/ jì;:llilul s\ t: 1.q_ 81 LI Àt{Y THE PHYSIOLOGY AND IMMUNOLOGY OF THE ENDOCRINE TESTIS by Simon MADDOCKS, B.Ag.Scl. (Hons) A thesls submltted to the Unlversfty of Adelalde ln fulfl'lment of the requlrements for the degree of Doctor of PhllosoPhY Department of Anlmal Scfences Walte Agrlcultural Research Instltute The UnlversitY of Adelalde March 1987 lì,.,ì,r(,:,td r/ riÈ"1 Know'ledge and wlsdom far f rom belng oner. Have ofl tlmes no connexion. Knorledge dwells In heads replete with thoughts of other men; Wlsdom ln minds attentlve to thelr otvn' Know'ledger a rude unprof ltab'le massr The meré materials with whlch wlsdom bul'ldsr Tfl.|smoothldandsquarldandflttedtoftsplacer Does but encumber whom lt seems trenrlch' Knowledge ls proud that he has learnrd so much; Wisdom ls humb'le that he knows no more' I{il'l lam CowPer ( 1731-1800) '_ .å Cowper Poetical Works TABLE OF CONTENTS f CONTENTS vii ABSTRACT x DECLARATION xl ACKNOt{LEDGEMENTS PREFACE xlff PART I: T CTIAPTER I: INTRODUCTION 2 1. 1. INTRODUCTION 2 L.2, THE PHYSIOLOGY OF THE ENDOCRINE TESTIS L.2,L. Introducti on 2 L.2.2. The Leydfg cells 7 r.2,2. I, Anatomy 7 L.2.2. 2. Relatiónship to blood vessels, lymph vessels and seminiferous tubul es L2 .2.2 3, Re]atfonshlp to other ce]ls in fnterstlt'lal tissue I5 I 18 ,212 4. Hormones produced by the Leydfg ce1ìs I 22 L .2.3 The Sertoll cells 24 T .2,3 I. AnatomY I .2.3 2. -
Konturen VI (2014) 1
Konturen VI (2014) 1 Introduction: Defining the Human and the Animal Alexander Mathäs University of Oregon Foreword: First, I would like to thank the contributors to this special volume of Konturen: Defining the Human and the Animal. All the authors presented drafts of their manuscripts at a conference on this topic, which took place on May 2 and 3, 2013 at the University of Oregon. I am grateful to the German Academic Exchange Service (DAAD), the Oregon Humanities Center, the Journal of Comparative Literature, the Univeristy of Oregon’s College of Arts and Sciences, Department of Philosophy, Department of Comparative Literature, the German Studies Committee, and the Department of German and Scandinavian for their generous support. Without them both the conference and the ensuing publication would not have been possible. Special thanks go to my departmental colleagues, and foremost to my Department Head and Chair of the German Studies Committee, Jeffrey Librett, who gave me the opportunity to publish this volume. I am grateful for the support of Alexis Smith, Eva Hofmann, Stephanie Chapman, and Judith Lechner, who assisted me at various stages of the project. I am also indebted to the graduate students who participated in a class on Human-Animal borders that I taught in Winter 2013. Sarah Grew’s assistance with the web design is greatly appreciated. And I would like to thank our office staff, above all Barbara Ver West and Joshua Heath, who were of great help in organizing and advertising the conference. Introduction: In recent years the fairly new field of Animal Studies has received considerable attention (see bibliography). -
Deutsche Nationalbibliografie 2013 a 19
Deutsche Nationalbibliografie Reihe A Monografien und Periodika des Verlagsbuchhandels Wöchentliches Verzeichnis Jahrgang: 2013 A 19 Stand: 08. Mai 2013 Deutsche Nationalbibliothek (Leipzig, Frankfurt am Main) 2013 ISSN 1869-3946 urn:nbn:de:101-ReiheA19_2013-3 2 Hinweise Die Deutsche Nationalbibliografie erfasst eingesandte Pflichtexemplare in Deutschland veröffentlichter Medienwerke, aber auch im Ausland veröffentlichte deutschsprachige Medienwerke, Übersetzungen deutschsprachiger Medienwerke in andere Sprachen und fremdsprachige Medienwerke über Deutschland im Original. Grundlage für die Anzeige ist das Gesetz über die Deutsche Nationalbibliothek (DNBG) vom 22. Juni 2006 (BGBl. I, S. 1338). Monografien und Periodika (Zeitschriften, zeitschriftenartige Reihen und Loseblattausgaben) werden in ihren unterschiedlichen Erscheinungsformen (z.B. Papierausgabe, Mikroform, Diaserie, AV-Medium, elektronische Offline-Publikationen, Arbeitstransparentsammlung oder Tonträger) angezeigt. Alle verzeichneten Titel enthalten einen Link zur Anzeige im Portalkatalog der Deutschen Nationalbibliothek und alle vorhandenen URLs z.B. von Inhaltsverzeichnissen sind als Link hinterlegt. In Reihe A werden Medienwerke, die im Verlagsbuch- chende Menüfunktion möglich. Die Bände eines mehrbän- handel erscheinen, angezeigt. Auch außerhalb des Ver- digen Werkes werden, sofern sie eine eigene Sachgrup- lagsbuchhandels erschienene Medienwerke werden an- pe haben, innerhalb der eigenen Sachgruppe aufgeführt, gezeigt, wenn sie von gewerbsmäßigen Verlagen vertrie- ansonsten -
Review Effects of Thyroid Hormones on Leydig Cells in the Postnatal Testis
Histol Histopathol (2004) 19: 985-997 Histology and http://www.hh.um.es Histopathology Cellular and Molecular Biology Review Effects of thyroid hormones on Leydig cells in the postnatal testis S.M.L.C. Mendis-Handagama and H.B.S. Ariyaratne* Department of Comparative Medicine, The University of Tennessee College of Veterinary Medicine, Knoxville, TN, USA *Present address: Department of Veterinary Basic Sciences, Faculty of Veterinary Medicine & Animal Science, University of Peradeniya, Sri Lanka Summary. Thyroid hormones (TH) stimulate oxidative Key words: Thyroid hormone, Leydig cells, Stem cell metabolism in many tissues in the body, but testis is not differentiation, Leydig progenitor cells, Steroidogenesis, one of them. Therefore, in this sense, testis is not Aging considered as a target organ for TH. However, recent findings clearly show that TH have significant functions on the testis in general, and Leydig cells in particular; Introduction this begins from the onset of their differentiation through aging. Some of these functions include triggering the Leydig cells are the main source of androgens in the Leydig stem cells to differentiate, producing increased mammalian male. In this paper, efforts have been made numbers of Leydig cells during differentiation by to review the available literature on TH on Leydig cells causing proliferation of Leydig stem cells and in the postnatal testis. progenitors, stimulation of the Leydig cell steroidogenic function and cellular maintenance. The mechanism of Leydig Cells action of TH on Leydig cell differentiation is still not clear and needs to be determined in future studies. Franz Leydig, a scientist from Germany, first However, some information on the mechanisms of TH described the Leydig cells in the testis interstitium in action on Leydig cell steroidogenesis is available. -
The Philosophical and Historical Roots of Evolutionary Tree Diagrams
Evo Edu Outreach (2011) 4:515–538 DOI 10.1007/s12052-011-0355-0 HISTORYAND PHILOSOPHY Depicting the Tree of Life: the Philosophical and Historical Roots of Evolutionary Tree Diagrams Nathalie Gontier Published online: 19 August 2011 # Springer Science+Business Media, LLC 2011 Abstract It is a popularly held view that Darwin was the were the result of this blend would, from the nineteenth first author to draw a phylogenetic tree diagram. However, century onward, also include the element of time. The as is the case with most popular beliefs, this one also does recognition of time would eventually lead to the recognition not hold true. Firstly, Darwin never called his diagram of of evolution as a fact of nature, and subsequently, tree common descent a tree. Secondly, even before Darwin, tree iconographies would come to represent exclusively the diagrams were used by a variety of philosophical, religious, evolutionary descent of species. and secular scholars to depict phenomena such as “logical relationships,”“affiliations,”“genealogical descent,”“af- Keywords Species classification . Evolutionary finity,” and “historical relatedness” between the elements iconography. Tree of life . Networks . Diagram . Phylogeny. portrayed on the tree. Moreover, historically, tree diagrams Genealogy. Pedigree . Stammbaum . Affinity. Natural themselves can be grouped into a larger class of diagrams selection that were drawn to depict natural and/or divine order in the world. In this paper, we trace the historical roots and cultural meanings of these tree diagrams. It will be Introduction demonstrated that tree diagrams as we know them are the outgrowth of ancient philosophical attempts to find the In this paper, we focus on the “why” of tree iconography. -
Copyrighted Material
Chapter 1 History Systematics has its origins in two threads of biological science: classification and evolution. The organization of natural variation into sets, groups, and hierarchies traces its roots to Aristotle and evolution to Darwin. Put simply, systematization of nature can and has progressed in absence of causative theories relying on ideas of “plan of nature,” divine or otherwise. Evolutionists (Darwin, Wallace, and others) proposed a rationale for these patterns. This mixture is the foundation of modern systematics. Originally, systematics was natural history. Today we think of systematics as being a more inclusive term, encompassing field collection, empirical compar- ative biology, and theory. To begin with, however, taxonomy, now known as the process of naming species and higher taxa in a coherent, hypothesis-based, and regular way, and systematics were equivalent. Roman bust of Aristotle (384–322 BCE) 1.1 Aristotle Systematics as classification (or taxonomy) draws its Western origins from Aris- totle1. A student of Plato at the Academy and reputed teacher of Alexander the Great, Aristotle founded the Lyceum in Athens, writing on a broad variety of topics including what we now call biology. To Aristotle, living things (species) came from nature as did other physical classes (e.g. gold or lead). Today, we refer to his classification of living things (Aristotle, 350 BCE) that show simi- larities with the sorts of classifications we create now. In short, there are three featuresCOPYRIGHTED of his methodology that weMATERIAL recognize immediately: it was functional, binary, and empirical. Aristotle’s classification divided animals (his work on plants is lost) using Ibn Rushd (Averroes) functional features as opposed to those of habitat or anatomical differences: “Of (1126–1198) land animals some are furnished with wings, such as birds and bees.” Although he recognized these features as different in aspect, they are identical in use. -
Anatomy and Physiology of Male Gametogenesis
1 Anatomy and Physiology of Male Gametogenesis Alex Varghese, Fnu Deepinder, Angali Chandra, Ang Wen Jeat, Furquan Pathan, Ashok Agarwal ABSTRACT Basic understanding of the male reproductive system is fundamental in effective evaluation and treatment of male infertility. This chapter is a concise introduction to the male reproductive anatomy and the intricately designed process of spermatogenesis along with its hormonal control. INTRODUCTION Understanding the fundamentals of anatomy and physiology of male reproductive system is a key to effective evaluation and treatment of male infertility. It comprises of the hypothalamic-pituitary-testis axis, epididymis, vas deferens, seminal vesicles, prostate and urethra. ANATOMY OF MALE REPRODUCTIVE SYSTEM Development The male urinary and reproductive systems share a common developmental origin. The testes and extra-testicular ducts arise from three different tissues: intermediate mesoderm, mesodermal epithelium and primordial germ cells. • The intermediate mesoderm forms a urogenital ridge that gives rise to testicular stroma and the mesonephric (Wolffian) duct. • The mesodermal (coelomic) epithelium gives rise to Sertoli cells and the paramesonephric duct. • The primordial germ cells migrate from yolk sac and give rise to the spermatagonia. Sexual differentiation occurs in the seventh week of gestation in embryos carrying the Y-chromosome. 4 ANDROLOGY LABORATORY MANUAL Transcription of the SRY gene present on the Y-chromosome leads to synthesis of testis-determining factor (TDF) protein. Secretion of TDF protein stimulates the nascent Leydig cells to produce testosterone, causing development of the mesonephric duct. It also stimulates Sertoli cells to secrete Mullerian-inhibiting factor (MIF), which leads to the regression of the paramesonephric duct. This cascade of events leads to the formation of male internal genital organs. -
Karl Von Den Steinen's Ethnography in the Context of the Brazilian Empire
http://dx.doi.org/10.1590/2238-38752017v828 1 Campinas State University (UNICAMP), Campinas, SP, Brazil [email protected] Erik PetscheliesI KARL VON DEN STEINEN’S ETHNOGRAPHY IN THE CONTEXT OF THE BRAZILIAN EMPIRE aug, 2018 aug, 569, may.– 569, – 1 Karl von den Steinen sociol. antropol. | rio de janeiro, v.08.02: 543 | rio de janeiro, antropol. sociol. karl von den steinen’s ethnography in the context of the brazilian empire 544 INTRODUCTION The Swedish ethnologist Erland Nordenskiöld (1877-1932) described his friend and professional colleague Karl von den Steinen (1855-1929) as the “doyen of ethnographic explorers of South America” in an obituary published in the Jour- nal de la Société des Américanistes (Nordenskiöld, 1930: 221).1 Von den Steinen undertook the first two exploratory trips to the Xingu River basin (in the Brazil- ian Amazon), formerly considered terra incognita: the first in 1884, the second between 1887 and 1888. In addition to this “extremely remarkable journey from a geographical point of view,” Karl von den Steinen, Nordenskiöld proceeded, was able to “discover a region of America, where the Indians had not yet abso- lutely suffered the influence of the civilization of the white men, and he was able to take full advantage of this discovery from a scientific point of view.” In short, “for his profound studies of the civilization of the Xingu tribes, Karl von den Steinen’s travels have been extraordinarily useful to exploration. If one flicks through any book on ethnography, history, religion, psychology or the history of cultivated plants, one always finds his name and often a few lines of this genius who inspired whole treatises about the other” (Nordenskiöld, 1930: 222). -
Ernst Haeckel and the Morphology of Ethics Nolan Hele
Document généré le 26 sept. 2021 19:41 Journal of the Canadian Historical Association Revue de la Société historique du Canada Ernst Haeckel and the Morphology of Ethics Nolan Hele Volume 15, numéro 1, 2004 URI : https://id.erudit.org/iderudit/012066ar DOI : https://doi.org/10.7202/012066ar Aller au sommaire du numéro Éditeur(s) The Canadian Historical Association/La Société historique du Canada ISSN 0847-4478 (imprimé) 1712-6274 (numérique) Découvrir la revue Citer cet article Hele, N. (2004). Ernst Haeckel and the Morphology of Ethics. Journal of the Canadian Historical Association / Revue de la Société historique du Canada, 15(1), 1–27. https://doi.org/10.7202/012066ar Tous droits réservés © The Canadian Historical Association/La Société Ce document est protégé par la loi sur le droit d’auteur. L’utilisation des historique du Canada, 2004 services d’Érudit (y compris la reproduction) est assujettie à sa politique d’utilisation que vous pouvez consulter en ligne. https://apropos.erudit.org/fr/usagers/politique-dutilisation/ Cet article est diffusé et préservé par Érudit. Érudit est un consortium interuniversitaire sans but lucratif composé de l’Université de Montréal, l’Université Laval et l’Université du Québec à Montréal. Il a pour mission la promotion et la valorisation de la recherche. https://www.erudit.org/fr/ chajournal2004.qxd 12/01/06 14:11 Page 1 Ernst Haeckel and the Morphology of Ethics NOLAN HEIE n 10 May 1907, Johannes Reinke,1 a Professor of botany at the University Oof Kiel and member of the Prussian upper chamber, the