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From their largely descriptive beginnings about a half century ago, studies on the ecology of small mammals have mushroomed in number, scope, content and complexity. Yet strangely, or perhaps not so strangely if one considers the extent and complexity of ecological interactions, the main problems for which the early workers sought answers still defy complete analysis, and basic hypotheses remain untested if not even untestable. The same holds true for so many branches of animal ecology that it seems to be the complexity of the concepts that frustrates efforts rather than the subject species. Like all branches of science, small mammal ecology has been subject to a series of fashionable approaches, one following another as tech nology penetrates previously impregnable regions. Doubtless the future development of our science will be punctuated by wave upon wave of new endeavour in whole fields that are perhaps even yet unidentified. Answers to the complex questions which ecologists ask do not come easily. Increasingly though, they arise in direct proportion to the efforts expended upon their elucidation. Many studies have achieved such a high level of elegance, in terms of manpower and apparatus, that there is a feeling that questions asked when such resources are unavailable are not worth asking. Nothing could be further from the truth. Many a complex model has failed fully to explain the phenomenon for which it was construc ted because of a lack of basic field data on the species' natural h~story.
It is two years since a general meeting of the Gesellschaft fur Biologische Chemie first requested us to organize the 21 st Mosbach Colloquium on mammalian reproduction, and one year since we received final authorization to do so. The present volume contains the papers read at the Colloquium, but the discussions have been omitted because writing and proof reading them would have delayed the appearance of this volume for an unjustifiable long time. Besides, in most cases the discussion was of a relatively specific nature and we did not consider it essential, bearing in mind that the purpose of the Mosbach Col loquia is to provide advanced further education for the non specialist. One of us has referred to this and to the topical structure of the 21 st Colloquium in the introductory and final remarks. Helpful suggestions for organizing the program were made by some of the invited speakers, but the first important impulses VON BERSWORDT-WALLRABE, Dr. ELGER, Dr. came from Dr. GERHARDS, Dr. NEUMANN, and Dr. UFER to whom we here wish express our thanks. Thanks are also due to those whose donations, some of which were very generous, made it financially possible to organize the Colloquium. HEINZ GIBIAN July 1970 ERNST JURGEN PLOTZ Contents Introduction. H. GIBIAN (Berlin) 1 General Outline about Reproductive Physiology and its Developmental Background. A. JOST (Paris) .. 4 The Significance of Hormones in Mammalian Sex Differentia tion as Evidenced by Experiments with Synthetic Andro gens and Antiandrogens. W. ELGER, F. NEUMANN, H.
Understanding the innervation of the esophagus is a prerequisite for successful treatment of a variety of disorders, e.g., dysphagia, achalasia, gastroesophageal reflux disease (GERD) and non-cardiac chest pain. Although, at first glance, functions of the esophagus are relatively simple, their neuronal control is considerably complex. Vagal motor neurons of the nucleus ambiguus and preganglionic neurons of the dorsal motor nucleus innervate striated and smooth muscle, respectively. Myenteric neurons represent the interface between the dorsal motor nucleus and smooth muscle but are also involved in striated muscle innervation. Intraganglionic laminar endings (IGLEs) represent mechanosensory vagal afferent terminals. They also establish intricate connections with enteric neurons. Afferent information is implemented by the swallowing central pattern generator in the brainstem, which generates and coordinates deglutitive activity in both striated and smooth esophageal muscle and orchestrates esophageal sphincters as well as gastric adaptive relaxation. Disturbed excitation/inhibition balance in the lower esophageal sphincter results in motility disorders, e.g., achalasia and gastroesophageal reflux disease. Loss of mechanosensory afferents disrupts adaptation of deglutitive motor programs to bolus variables, eventually leading to megaesophagus. Both spinal and vagal afferents appear to contribute to painful sensations, e.g., non-cardiac chest pain. Extrinsic and intrinsic neurons may be involved in intramural reflexes using acetylcholine, nitric oxide, substance P, CGRP and glutamate as main transmitters. In addition, other molecules, e.g., ATP, GABA and probably also inflammatory cytokines may modulate these neuronal functions.
The Springer Handbook of Auditory Research presents a series of comprehen sive and synthetic reviews of the fundamental topics in modern auditory research. The volumes are aimed at all individuals with interests in hearing research including advanced graduate students, postdoctoral researchers, and clinical investigators. The volumes are intended to introduce new investi gators to important aspects of hearing science and to help established inves tigators to better understand the fundamental theories and data in fields of hearing that they may not normally follow closely. Each volume is intended to present a particular topic comprehensively, and each chapter will serve as a synthetic overview and guide to the lit erature. As such, the chapters present neither exhaustive data reviews nor original research that has not yet appeared in peer-reviewed journals. The volumes focus on topics that have developed a solid data and conceptual foundation rather than on those for which a literature is only beginning to develop. New research areas will be covered on a timely basis in the series as they begin to mature. Each volume in the series consists of five to eight substantial chapters on a particular topic. In some cases, the topics will be ones of traditional interest for which there is a substantial body of data and theory, such as auditory neuroanatomy (Vol. 1) and neurophysiology (Vol. 2). Other volumes in the series will deal with topics which have begun to mature more recently, such as development, plasticity, and computational models of neural processing.
Martens and Fishers (Martes) in Human-Altered Environments: An International Perspective examines the conditions where humans and martens are compatible and incompatible, and promotes land use practices that allow Martes to be representatively distributed and viable.

All Martes have been documented to use forested habitats and 6 species (excluding the stone marten) are generally considered to require complex mid- to late-successional forests throughout much of their geographic ranges. All species in the genus require complex horizontal and vertical structure to provide escape cover protection from predators, habitat for their prey, access to food resources, and protection from the elements. Martens and the fisher have high metabolic rates, have large spatial requirements, have high surface area to volume ratios for animals that often inhabit high latitudes, and often require among the largest home range areas per unit body weight of any group of mammals. Resulting from these unique life history characteristics, this genus is particularly sensitive to human influences on their habitats, including habitat loss, stand-scale simplification of forest structure via some forms of logging, and landscape-scale effects of habitat fragmentation. Given their strong associations with structural complexity in forests, martens and the fisher are often considered as useful barometers of forest health and have been used as ecological indicators, flagship, and umbrella species in different parts of the world. Thus, efforts to successfully conserve and manage martens and fishers are associated with the ecological fates of other forest dependent species and can greatly influence ecosystem integrity within forests that are increasingly shared among wildlife and humans.

We have made great strides in our fundamental understanding of how animals with these unique life history traits perceive and utilize habitats, respond to habitat change, and how their populations function and perform under different forms of human management and mismanagement. This knowledge enhances our basic understanding of all species of Martes and will help us to achieve the goal of conserving viable populations and representative distributions of the world's Martes, their habitats, and associated ecological communities in our new millennium.

The studies described here were carried out in the Neuroregul ation Group, Department of Physiology, University of Leiden, the Netherlands. Over the last decade, this group, in close collaboration with the Department of Neurosurgery of the Academic Hospital of Leiden, has studied the development of the central nervous system from a neuroanatomical as well as a clinical perspective. During this period, the expression of several morphore gulators in the developing rat spinal cord was extensively investigated. Parallel studies focused on the development of the spinal cord fiber systems, which was studied by means of the intrauterine use of neuronal tracers. The main goal of these studies was to extend our knowledge about the (normal) generation of the spinal cord and to contribute to the under standing of clinical problems related to regeneration and degeneration in the mammalian central nervous system. The studies on morphoregulators, in particular, appeared to benefit two different scientific areas. Firstly, the correlation between morphoregulator expression patterns and known anatomy contributed to our knowledge about spinal cord development. Secondly, the correlation between morpho regulator expression patterns and known developmental processes may help to understand their precise function(s). This volume of Advances in Anatomy, Embryology and Cell Biology presents these particular studies on the development of the rat spinal cord performed over the last decade. As well as integrating the results of the tracer studies, this volume also provides an update on the development of the rat spinal cord.
Tree shrews are small-bodied, scansorial, squirrel-like mammals that occupy a wide range of arboreal, semi-arboreal, and forest floor niches in Southeast Asia and adjacent islands. Comparative aspects of tree shrew biology have been the subject of extensive investigations during the past two decades. These studies were initiated in part because of the widely accepted belief that tupaiids are primitive primates, and, as such, might provide valuable insight into the evolutionary origin of complex patterns of primate behavior, locomotion, neurobiology, and reproduction. During the same period, there has been a renewed interest in the methodology of phylogenetic reconstruction and in the use of data from a variety of biological disciplines to test or formulate hypotheses of evolutionary relationships. In particular, interest in the com parative and systematic biology of mammals has focused on analysis of phy logenetic relationships among Primates and a search for their closest relatives. Assessment of the possible primate affinities of tree shrews has comprised an important part of these studies, and a considerable amount of dental, cranio skeletal, neuroanatomical, reproductive, developmental, and molecular evi dence has been marshalled to either corroborate or refute hypotheses of a special tupaiid-primate relationship. These contrasting viewpoints have re sulted from differing interpretations of the basic data, as well as alternative approaches to the evolutionary analysis of data.
The past decade has witnessed a tremendous surge of interest in varied aspects of primate biology, encompassing virtually all disciplines of the biological sciences. Regardless of whether these studies have been approached from a paleontological, morphological, developmental, biochemical, neuroanatomical, or behavioral point of view, one under lying theme has been a common interest in the possible phylogenetic relationships suggested by the results of such studies. In some cases, sound taxonomic principles have not been followed in the interpretation of these data, and this has led to skepticism among many taxonomists with regard to the validity of some of the genealogical relationships and conclusions suggested by comparative studies of living primates. It is generally agreed that the fossil record alone provides the essential time dimension for directly observing changes in characteristics, but unfortunately this record is limited both in the number of genera represented and particularly in the incomplete nature of the available preserved material. On the other hand, extensive comparative analyses of numerous characteristics in living primates have provided additional insight into possible phylogenetic relationships, despite the lack of a time dimension. Such studies of both fossil and living primates are enhanced considerably by a cladistic analysis of the probable primitive (ancestral) or advanced (derived) condition of each character state discussed, based upon their distribution (and ontogeny, wherever possible) in a wide variety of primate and nonprimate taxa, including other eutherian mammals, marsupials, mono tremes, and reptiles.
As indicated in the Preface, the contributions to this volume are based upon the papers presented at the symposium on Thermoreceptors and Temperature Regula tion held in July 1988 at the Institute of Physiology of the University of Marburg (Federal Republic of Germany) to celebrate and commemorate the life and achievements of HERBERT HENSEL, who directed that Institute from 1955 until his death in 1983, and whose most notable and significant contributions to thermo physiology were in the areas of the properties and characteristics of thermo sensors, mammalian thermoregulation more generally, and the psychophysiology of ther mal sensation. All the papers in this volume deal, to a greater or lesser extent, with these discernibly different but closely allied aspects of mammalian physiology. The editors have sought to achieve cohesion, flow, and balance both in the contributed articles and in their order of presentation, without either large gaps or redundancies in the coverage of the recent advances in the understanding of thermoreceptors and thermoregulation. At the same time we have sought to avoid such a degree of editorial control as to destroy the individuality of the contributions, and the judgements upon which they were based. We have also sought to look both backwards and forwards, and to include some legitimate extension of the con sideration of thermosensitivity and thermoregulation into such areas as climatic adaptation and fever. Hence the "greater or lesser" of the closeness of this series of papers to HERBERT HENSEL'S scientific interests.
Mammalian cell lines command an effective monopoly for the production of therapeutic proteins that require post-translational modifications. This unique advantage outweighs the costs associated with mammalian cell culture, which are far grater in terms of development time and manufacturing when compared to microbial culture. The development of cell lines has undergone several advances over the years, essentially to meet the requirement to cut the time and costs associated with using such a complex hosts as production platforms.

This book provides a comprehensive guide to the methodology involved in the development of cell lines and the cell engineering approach that can be employed to enhance productivity, improve cell function, glycosylation and secretion and control apoptosis. It presents an overall picture of the current topics central to expression engineering including such topics as epigenetics and the use of technologies to overcome positional dependent inactivation, the use of promoter and enhancer sequences for expression of various transgenes, site directed engineering of defined chromosomal sites, and examination of the role of eukaryotic nucleus as the controller of expression of genes that are introduced for production of a desired product. It includes a review of selection methods for high producers and an application developed by a major biopharmaceutical industry to expedite the cell line development process. The potential of cell engineering approch to enhance cell lines through the manipulation of single genes that play important roles in key metabolic and regulatory pathways is also explored throughout.

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