Sociolinguistics provides a powerful instrument by which we can interpret the contemporary and near-contemporary use of language in relation to the society in which speakers live. Almost since the ...beginning of the discipline, however, attempts have been made to extrapolate backwards and interpret past linguistic change sociolinguistically. Some of these findings have influenced the discussion of the history of the English language as portrayed in the many textbooks for undergraduate courses. A consistent application of sociolinguistic theory and findings has rarely been attempted, however, despite the specialist literature which demonstrates this connection at specific points in the language's development.
This textbook provides students with a means by which a previously existing knowledge of a linear, narrative, history of English can be deepened by a more profound understanding of the sociolinguistic forces which initiate or encourage language change. Uniquely, it discusses not only the central variationist tendencies present in language change and their analysis but also the macrosociolinguistic forces which act upon all speakers and their language. Chapters investigate the political, cultural and economic forces which affect a society's use of and views on language; language contact, language standardisation and linguistic attrition are also covered. Discussion is illustrated throughout by apposite examples from the history of English. The volume enables students to develop a deeper understanding of both sociolinguistics and historical linguistics; it is also be useful as a primer for postgraduate study in the subjects covered.
Procreation is essential for survival of species. Not surprisingly, complex neuronal networks have evolved to mediate the diverse internal and external environmental inputs that regulate reproduction ...in vertebrates. Ultimately, these regulatory factors impinge, directly or indirectly, on a final common pathway, the neurons producing the gonadotropin-releasing hormone (GnRH), which stimulates pituitary gonadotropin secretion and thereby gonadal function. Compelling evidence, accumulated in the last few years, has revealed that kisspeptins, a family of neuropeptides encoded by the Kiss1 gene and produced mainly by neuronal clusters at discrete hypothalamic nuclei, are pivotal upstream regulators of GnRH neurons. As such, kisspeptins have emerged as important gatekeepers of key aspects of reproductive maturation and function, from sexual differentiation of the brain and puberty onset to adult regulation of gonadotropin secretion and the metabolic control of fertility. This review aims to provide a comprehensive account of the state-of-the-art in the field of kisspeptin physiology by covering in-depth the consensus knowledge on the major molecular features, biological effects, and mechanisms of action of kisspeptins in mammals and, to a lesser extent, in nonmammalian vertebrates. This review will also address unsolved and contentious issues to set the scene for future research challenges in the area. By doing so, we aim to endow the reader with a critical and updated view of the physiological roles and potential translational relevance of kisspeptins in the integral control of reproductive function.
Abstract The type II gonadotropin‐releasing hormone (GnRH‐II) was first discovered in chicken ( Gallus gallus ) brain and then shown to be present in many vertebrates. Indeed, its structure is ...conserved unchanged throughout vertebrate evolution from teleost fish through to mammals suggesting a crucial function. Yet the functional significance has been largely unexplored. Studies in comparative endocrinology show that the GnRH‐II system is differentially functional in mammalian species. Intact GnRH‐II neuropeptide and receptor genes ( GnRH2 and GnRH receptor 2 GnRHR2 ) occur in marmoset monkeys ( Callithrix jacchus ), musk shrews ( Suncus murinus ) and pigs ( Sus scrofa ). However, one or other or both of these genes are inactivated in other species, where mutations or remnants affecting GnRH 2 neuropeptide and/or type II GnRHR exons are retained in conserved genomic loci. New data from DNA sequencing projects facilitate extensive analysis of species‐specific variation in these genes. Here, we describe GnRH2 and GnRHR2 genes spanning a collection of 21 taxonomic orders, encompassing around 140 species from Primates, Scandentia, Eulipotyphla, Rodentia, Lagomorpha, Artiodactyla, Carnivora, Perissodactyls, Pholidota, Chiroptera, Afrotheria, Xenarthra and Marsupialia. Intact coding exons for both GnRH2 and GnRHR2 occur in monkeys, tree shrews, shrews, moles, hedgehogs, several rodents (degu, kangaroo‐rat, pocket mouse), pig, pecarry and warthog, camels and alpaca, bears, Weddell seal, hyena, elephant, aardvark and marsupials. Inactivating mutations affecting GnRH2 and GnRHR2 , some located at conserved sites within exons, occur in species of primates, most rodents, lagomorphs, bovidae, cetaceans, felidae, canidae and other carnivora, pangolins, most bats, armadillo, brushtail and echidna. A functional GnRH‐II system appears retained within several taxonomic families of mammals, but intact retention does not extend to whole taxonomic orders. Defining how endogenous GnRH‐II neuropeptide operates in different mammals may afford functional insight into its actions in the brain, especially as, unlike the type I GnRH system, it is expressed in the mid brain and not the hypothalamus.
Much has been written on dialect formation through contact between dialects of the same language, but the question of what happens when closely related but linguistically discrete varieties come into ...contact with each other has largely been neglected. Here Robert McColl Millar sets out to redress this imbalance.
The existence of a hypothalamic gonadotropin-inhibiting system has been elusive. A neuropeptide named gonadotropin-inhibitory hormone (GnIH, SIKPSAYLPLRF-NH(2)) which directly inhibits gonadotropin ...synthesis and release from the pituitary was recently identified in quail hypothalamus. Here we identify GnIH homologs in the human hypothalamus and characterize their distribution and biological activity. GnIH homologs were isolated from the human hypothalamus by immunoaffinity purification, and then identified as MPHSFANLPLRF-NH(2) (human RFRP-1) and VPNLPQRF-NH(2) (human RFRP-3) by mass spectrometry. Immunocytochemistry revealed GnIH-immunoreactive neuronal cell bodies in the dorsomedial region of the hypothalamus with axonal projections to GnRH neurons in the preoptic area as well as to the median eminence. RT-PCR and subsequent DNA sequencing of the PCR products identified human GnIH receptor (GPR147) mRNA expression in the hypothalamus as well as in the pituitary. In situ hybridization further identified the expression of GPR147 mRNA in luteinizing hormone producing cells (gonadotropes). Human RFRP-3 has recently been shown to be a potent inhibitor of gonadotropin secretion in cultured sheep pituitary cells by inhibiting Ca(2+) mobilization. It also directly modulates GnRH neuron firing. The identification of two forms of GnIH (RFRP-1 and RFRP-3) in the human hypothalamus which targets human GnRH neurons and gonadotropes and potently inhibit gonadotropin in sheep models provides a new paradigm for the regulation of hypothalamic-pituitary-gonadal axis in man and a novel means for manipulating reproductive functions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Modern Scots Millar, Robert McColl
2018, 2018-03-07
eBook
This textbook overview of Modern Scots provides a description and analysis of the language covering lexical, phonological and structural patterns. It presents evidence for the diversity of the ...language through illustrations from newly collected fieldwork material. Frequent, detailed analysis of local variation is combined with a central focus is on the overall patterning of Scots. McColl Millar also examines the present and future of Scots, considering both its use in literature and other media and ongoing language policy and planning. A dedicated chapter introduces the reader to the various research methods and available resources – including corpora, atlases and dictionaries – and provides guidance on how to use them effectively. Each chapter concludes with a series of exercises to complete and issues to discuss, encouraging active engagement and development of skill and knowledge in relation to the subject matter. This textbook offers a practical and engaging survey of Modern Scots making this an essential resource, aptly structured for use on Modern Scots and modern varieties of English modules.
This book considers various theoretical and methodological issues in relation to a representative sample of fishing communities along Scotland's east coast. Can the lexical variation and change found ...in these communities be perceived as primary evidence fordialect death?
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