The developmental history of Mutela bourguignati (Ancey) Bourguignat (Mollusca: Bivalvia)

1961 ◽  
Vol 244 (711) ◽  
pp. 259-298 ◽  
Keyword(s):  
Ventral Surface ◽  
Main Body ◽  
South American ◽  
Freshwater Bivalve ◽  
Byssus Thread ◽  
Larval Stages ◽  
Large Numbers ◽  
History Of ◽  
And Function ◽  
First Time

An account is given for the first time of the development of Mutela bourguignati (Ancey) Bourguignat, an African freshwater bivalve of the family Mutelidae. Eggs are shed in large numbers into the inner demibranchs. There they develop into minute larvae similar in some respects to the lasidium larvae of certain South American freshwater mussels, but differing in several ways. Each larva consists of a rounded body covered dorsally and laterally by a thin pellicle and provided anteriorly with two lobes clothed with cilia. Posteriorly, and on the ventral surface, are two sets of minute hooks. Anteriorly is a remarkable elongate, flaccid and colourless tentacle more than seventy times as long as the larva itself. There is no gut, nor can endodermal or mesodermal tissues be recognized as such at this stage. After liberation via the exhalant siphon these larvae settle on the cyprinid fish Barbus altianalis radcliffi and there metamorphose and begin a parasitic phase of development. The larval pellicle folds, and its opposed edges fuse so as completely to enclose the larva. Two tubular outgrowths grow from its anterior end into the superficial tissues of the fish and serve both as organs of attachment and nutrition. In their vicinity skeletal tissues of the host are broken down. The main body of the larva, now designated the haustorial larva, elongates and becomes differentiated into a stalk and a bud. The stalk protrudes from the fish and bears the bud clear of the host. Within the bud the adult bivalve eventually develops. The stalk is traversed by long prolongations of the mantle which run into the haustorial tubes and function as absorptive tissues. The cuticle is not calcified nor is it composed of conchiolin. As differentiation proceeds the definitive mantle, which is the lineal descendant of the larval mantle, begins to secrete first periostracum then calcareous matter to form the rudiments of the valves, and a rudiment of the ligament is also formed. As adult features gradually appear the bud is burst and a young bivalve, little more than 1 mm in length, attached to a long stalk emerges. Independent, particulate feeding commences at this stage. Rupture of both cuticular and mantle elements eventually takes place at the point of juncture of stalk and young bivalve and the latter falls away to begin an independent existence. At the time of release it is capable of active locomotion and is able to produce a slender byssus thread. A detailed, illustrated account of these changes, both external and internal, is given, and the development of certain individual organs is traced. The nature of the cuticle of the haustorial larva, the effect of this larva on its host, and the affinities and probable evolution of the larval stages are discussed, and the importance of taking larval development into account in classification is emphasized.

"Itzt kommen die Soldaten"

2019 ◽  
Author(s):  
Tilman Venzl
Keyword(s):  
Literary History ◽  
18Th Century ◽  
Military History ◽  
Form And Function ◽  
Social Structural ◽  
History Of ◽  
The Subject ◽  
And Function ◽  
The Military ◽  
First Time

In the 18th century, as many as 300 German-language plays were produced with the military and its contact and friction with civil society serving as focus of the dramatic events. The immense public interest these plays attracted feeds not least on the fundamental social structural change that was brought about by the establishment of standing armies. In his historico-cultural literary study, Tilman Venzl shows how these military dramas literarily depict complex social processes and discuss the new problems in an affirmative or critical manner. For the first time, the findings of the New Military History are comprehensively included in the literary history of the 18th century. Thus, the example of selected military dramas – including Lessing's Minna von Barnhelm and Lenz's Die Soldaten – reveals the entire range of variety characterizing the history of both form and function of the subject.

scholarly journals The biology of Limacina retroversa

1954 ◽  
Vol 33 (2) ◽  
pp. 297-312 ◽  
Author(s):  
J. E. Morton
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Detailed Account ◽  
Larval Stages ◽  
Large Numbers ◽  
History Of ◽  
Clione Limacina

The Plymouth Fauna List contains records of two genera of pteropods, Limacina and Clione. Of the first, Limacina retroversa (Flem.) is by far the better-known species, apparently occurring regularly at Plymouth in large numbers in townettings from outside, and sometimes inside, the Sound. It breeds at Plymouth from June to August, and Lebour (1932) has given a detailed account of its breeding and larval stages and has discussed its role in the plankton. The second species of Limacina at Plymouth is lesueuri (d'Orbigny), which has been observed from time to time since 1906, when it was very common. The last record in the Fauna is off the Breakwater in 1920. Of the gymnosomatous pteropods, Clione limacina Phipps is the only species regularly occurring. Lebour (1931) has described the life history of this form, and mentions February to August as its months of greatest abundance. Its breeding season is June to August. Another gymnosome, tentatively referred to as Clionina longicauda, is reported by Russell (1936), and from the specimen department at Plymouth Laboratory the writer obtained some preserved specimens, not easily identifiable, of a Pneumodermopsis taken locally; its species is perhaps ciliata, recorded by Massy (1917) from the Irish Coast.

LABORATORY STUDIES ON THE TOXICITY OF INSECTICIDES TO THE BERTHA ARMYWORM (MAMESTRA CONFIGURATA) (LEPIDOPTERA: NOCTUIDAE)

1975 ◽  
Vol 107 (8) ◽  
pp. 865-872 ◽  
Author(s):  
C. R. Harris ◽  
S.A. Turnbull
Keyword(s):  
Direct Contact ◽  
Developmental Stages ◽  
Contact Toxicity ◽  
Mamestra Configurata ◽  
Larval Stages ◽  
Large Numbers ◽  
Third Stage ◽  
History Of ◽  
Dual Objectives ◽  
Bertha Armyworm

AbstractThis study had dual objectives: to select a series of insecticides toxic to the bertha armyworm, Mamestra configurata (Walk.), and to determine susceptibility of the various developmental stages to insecticides. Pupae were collected from infested rapeseed fields in Alberta and a laboratory rearing procedure suitable for production of large numbers of insects was devised. The direct contact toxicity of 50 insecticides to third-stage larvae was assessed. Methomyl and DDT were included as standard insecticides. None of the experimental insecticides was as toxic as methomyl but about one half were more toxic than DDT. Tests with representative organochlorine, organophosphorus, and carbamate insecticides indicated that all caused rapid knockdown of third-stage larvae. There was no evidence of subsequent recovery. After the life history of the bertha armyworm under controlled environmental conditions was determined, tests were conducted to ascertain the susceptibility of the various developmental stages to methomyl, chlorpyrifos, leptophos, and methidathion. Eggs and first and second stage larvae were more susceptible to direct contact applications of the insecticides than were the later larval stages, pupae, and adults.

The Underground Route to Mining: Afrikaners and the Witwatersrand Gold Mining Industry from 1902 to the 1907 Miners' Strike

1995 ◽  
Vol 36 (3) ◽  
pp. 467-489 ◽  
Author(s):  
Elaine N. Katz
Keyword(s):  
Gold Mining ◽  
Mining Industry ◽  
Work Force ◽  
Pipe Fitting ◽  
Conventional View ◽  
Wage Rates ◽  
Large Numbers ◽  
History Of ◽  
Discrete Category ◽  
First Time

This paper challenges the conventional view that the 1907 miners' strike constituted a landmark in the history of Afrikaner employment in the Witwatersrand gold mining industry. According to this view, the participation of Afrikaners during the dispute, as first-time miners and strike-breakers, gained them a permanent and proportionally large niche in the industry, for the first time. In sharp contrast, this paper demonstrates that Afrikaners already constituted a substantial percentage of white underground workers, particularly as a discrete category of workmen, the miners, well before the strike had even begunThe Afrikaner miners lacked training and mining skills. Yet, like the overseas professional miners, most of whom were British-born, they were classed as skilled workmen, eligible for skilled wages. This anomaly occurred because the so-called skills of the overseas professional miners were fragmented by the labour practices peculiar to the Rand. The expertise of the foreign miner derived from his all-round capabilities and experience. These were exclusively defined to constitute his so-called skill, and hence his skilled wage. But on the Witwatersrand, the overseas professional miners were required to draw on only one of their numerous accomplishments in a ‘specialized’, but only semi-skilled, capacity. They were employed either as supervisors of Africans, who performed drilling tasks, or as specialist pit men doing a single pit task among many: pump minding, pipe fitting, timbering or plate laying. Such fragmentation of the foreign miners' a11-round skills facilitated the entry of lesser trained men as miners, notably the Afrikaners.To become a miner, more specifically a supervisor, the Afrikaner needed only a brief period of specific instruction, which he acquired in one of several ways: through mine-sponsored experiments with unskilled white labour, rather than black; through the informal assistance of qualified miners; and through management-sponsored learner schemes intended to provide a core of compliant Afrikaner miners who would break the monopoly of skills and collective strength of the overseas professional miners. Such training enabled the Afrikaner to earn the compulsory, but readily available, blasting certificate, the award of which was confined to whites. Although most Afrikaners possessed this certificate, the hallmark of a skilled miner, they could not earn the customary white skilled wage because they were obliged to work under a System of contracts and not on day's pay.The incompetent Afrikaner miners nevertheless obtained billets easily, partly because of the industry's growth, but mainly because the overseas pioneer miners were decimated by the preventable occupational mining disease, silicosis: the locally born simply filled their places. The Afrikaners, of course, were also vulnerable to silicosis; but it was only from 1911 onwards that this gradually developing disease claimed them in significant numbers too.The overseas miners shunned the Afrikaners not only for ethnic reasons but also for material ones: they feared that the local miners, who were inefficient and had not been trained in the lengthy apprenticeships traditional in the industry, would undercut skilled wage rates. Management also scorned them because of their incompetence. Despite their relatively large numbers – they comprised at least one-third of the miners – the Afrikaners, who were unsuccessful, isolated and spurned, made little impact on the socio-economic and cultural fabric of the industry's work-force, either at the time of the 1907 strike or during its immediate aftermath.

The plankton and the benthos: origins and early history of an evolving relationship

Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 297-319 ◽  
Author(s):  
Philip W. Signor ◽  
Geerat J. Vermeij
Keyword(s):  
Benthic Communities ◽  
Marine Species ◽  
Suspension Feeding ◽  
Marine Animals ◽  
Suspension Feeders ◽  
Larval Stages ◽  
Large Numbers ◽  
Ultimate Cause ◽  
Marine Realm ◽  
History Of

Modern marine plankton communities include a broad diversity of metazoans that are suspension-feeding or micropredatory as adults. Many benthic marine species have larval stages that reside, and often feed, in the plankton for brief to very long periods of time, and most marine benthic communities include large numbers of suspension-feeders. This has not always been the case. Cambrian benthic communities included relatively few suspension-feeders. Similarly, there were few metazoan clades represented in the plankton, either as adult suspension-feeders or as larvae. Review of the fossil record suggests that the diversification of the plankton and suspension-feeding marine animals began in the Late Cambrian and continued into the Ordovician. These changes were accompanied by, and probably influenced, concurrent major changes in the marine realm, including an increase in tiering within benthic communities, the replacement of the Cambrian fauna by the Paleozoic fauna, and a general taxonomic diversification. The ultimate cause of these changes is uncertain, but it appears likely that the plankton was and is a refuge from predation and bioturbation for adults and larvae alike. The expansion in plankton biomass thus provided increased ecological opportunities for suspension-feeders in the plankton and benthos.

The oldest sigmodontine rodent revisited and the age of the first South American cricetids

2018 ◽  
Vol 93 (2) ◽  
pp. 368-384 ◽  
Author(s):  
Franck Barbière ◽  
Pablo E. Ortiz ◽  
Ulyses F.J. Pardiñas
Keyword(s):  
Phylogenetic Analysis ◽  
New Genus ◽  
Cranial Morphology ◽  
South American ◽  
Early Pliocene ◽  
Molecular Approaches ◽  
Fossil Material ◽  
History Of ◽  
New Interpretation ◽  
First Time

AbstractNew fossil material ofAuliscomys formosusReig 1978 allows restudy of the oldest known South American representative of the subfamily Sigmodontinae. Description ofAuliscomys formosuswas based on a fragmentary dentary exhumed from the Monte Hermoso Formation of central Argentina. Previous studies allocatedA. formosusto the early Pliocene. A reevaluation of dental and cranial morphology, including for the first time the upper dentition, and the inclusion ofA. formosusin a phylogenetic analysis of the tribe Phyllotini indicate thatA. formosusrepresents a new genus,Kraglievichimys.Kraglievichimysshares a mosaic of characters with the livingAuliscomysOsgood, 1915 andLoxodontomysOsgood, 1947. The taxonomic reassignment ofA. formosusand the possibility that the Monte Hermoso Formation may be younger than early Pliocene in age provide a new understanding of cricetid diversification in South America. Estimates of sigmodontine ancestry by molecular approaches are biased toward older ages, whereas this new interpretation of the history ofK. formosussuggests that the South American history of sigmodontines spans less than 4 million years.UUID:http://zoobank.org/49dd8f60-56b1-4e8a-a044-6cea3a1bd52b

scholarly journals Τοιχογραφίες ρωμαϊκών χρόνων στην Ελλάδα

2013 ◽  
Author(s):  
Νικόλαος Βαβλέκας
Keyword(s):  
Wall Paintings ◽  
Construction Technique ◽  
Imperial Period ◽  
Starting Point ◽  
History Of ◽  
And Function ◽  
Relationship Of ◽  
First Time ◽  
Wall Decoration

The thesis "Roman wall paintings in Greece. From the time of Augustus until the era of Constantine the Great"presents for the first time in an overall scale the wall paintings of Roman imperial era that have come to light in the areas of modern Greek territory.The thesis focuses on the nature and function of the material in question, as well as on the construction technique and its iconography. Specifically, the present study examines for the first time the relationship of iconography with the decorated interiors, the frequency of wall paintings within a building as well as the relations of wall decorations with the types of buildings. Moreover it focuses on a number of other issues, such as whether and to what extent the material in question had any meaning for the ancient owners who ordered it, to what extent the agenda of projects was dictated by personal preferences, economic or social status, the current dominant artistic trends of the time, the existence of a single common art for mural decorations throughout the empire, as well as the detection and further developments of certain Italian styles in the provinces of Greece. Also it tries to decipher to what extent we are able today with the limited resources, sources and data that we have to understand this material. This study includes six chapters each of which determines the material in question in a different light. The first chapter is an introduction to Roman wall paintings in general, while the second examines the technique of wall decoration during the imperial period. The third chapter presents briefly the history of wall paintings in the Greek area until the late Hellenistic era. In this chapter, having as a starting point the early Greek times, an effort has been made to determine the nature and function of the mural decoration in the Greek world before the advent of the Romans, as well as the dominant artistic trends of wall decoration until the late Hellenistic era. The fourth chapter examines in general the wall decorations during the imperial period in the area of modern Greece, having as a basis, locations that present more frequently mural decorations. The fifth chapter deals with the iconography of the Roman wall paintings in Greece. Despite the fragmentary state of preservation of the material in question it can be detected the common iconographic trends between the Greek and Italian wall decoration, although it can not be expressed any definite conclusion as far as the prevalence of the new artistic trends in mural decorations is concerned. The last chapter examines through statistics and comparative conclusions the nature and the function of the material in question, as well as in what kind of buildings (private / public) and spaces (character and function of the rooms) the mural decoration is appeared.

Basaglia's International Legacy: From Asylum to Community

2020 ◽  
Keyword(s):  
Mental Health ◽  
Transnational History ◽  
South American ◽  
Developed Country ◽  
Italian Law ◽  
Outright Rejection ◽  
History Of ◽  
The Uk ◽  
Psychiatric Beds ◽  
First Time

Italian Law 180 of 1978 is probably the most radical Mental Health Act ever passed. It forbade the admission of any new patients to mental hospitals forthwith and called for the rapid closure of such institutions. The Law crowned the work of the charismatic Italian psychiatrist Franco Basaglia and his ‘Democratic Psychiatry’ movement. The Italian reforms resulted in arguably the lowest number of psychiatric beds in any developed country, and have been widely debated and emulated. They have been adopted enthusiastically by several Mediterranean and South American countries. However, the implementation of Law 180 was patchy, with critics both internally and internationally. This book brings together historians and clinicians, including Basaglia’s colleagues and followers, for the first time. These authors report on the responses to the reforms from over 15 countries. These range from exuberant implementation in Brazil and Italy, through partial and localized initiatives in several countries, through to outright rejection in the UK and USA. These responses reflect differences in clinical and practical realities, but also professional rivalries and often profound conceptual differences. This is a transnational history of psychiatric debates, reform, and psychiatric practice. The excitement of Basaglia’s thinking and the Italian reforms is captured, as are the inconsistencies in both his thinking and practice. Basaglia and the Italian movement did not arrive from nowhere, and its global influences are also examined. Basaglia’s radical human rights agenda was expressed through psychiatric reforms. His ambivalences engaged artists and thinkers as well as clinicians, and his legacy, as this book vividly demonstrates, is far from straightforward.

The Earliest Motets: Music and Words

1989 ◽  
Vol 114 (2) ◽  
pp. 141-163 ◽  
Author(s):  
Norman E. Smith
Keyword(s):  
Central Importance ◽  
Musical Identity ◽  
Modern Times ◽  
General Acceptance ◽  
Medieval Music ◽  
Large Numbers ◽  
History Of ◽  
First Time

The birth of a genre surely is one of the most fascinating occurrences in the history of music, and no genre of medieval music had a more interesting birth than the motet. Study of the motet in modern times found special impetus and direction in 1898 when Wilhelm Meyer announced his discovery of the origin of the motet in the discant clausulae of the Notre Dame organa. Demonstrating the musical identity of certain Latin motets and discant clausulae, he concluded that the motet arose through the addition of Latin texts to the melismatic upper voices of the two-voice clausulae and was thereby able to explain for the first time the previously baffling and unprecedented verse structures of many motet texts. In doing so, he at the same time made it clear that he understood the French motet to be of later origin than the Latin and brushed aside special questions concerning the French type, such as, for example, its most provocative feature: its characteristic use of refrains. How was one to understand the presence of refrains in a French motet supposedly derived from a sacred, liturgical model? This and other difficult questions refused to disappear, and they continued to be raised from time to time, but Meyer's explanation of the origin of the motet gained general acceptance, most decisively and influentially from Friedrich Ludwig. All of Ludwig's writings on the motet bespeak his endorsement of Meyer's position, but nowhere more explicitly than in the Repertorium:These compositions [discant clausulae] were still more important by virtue of the fact that they served in rather large numbers as musical sources of motets, at first for Latin motets and later, although in more limited numbers, also for French motets - a fact, first recognized for the Latin motets by Wilhelm Meyer in 1898 (Der Ursprung des Motetts), claiming central importance for the history of music about 1200.

scholarly journals Rudolf Schlechter's South-American orchids IV. Schlechter's "network": Venezuela and Colombia

Lankesteriana ◽  
2021 ◽  
Author(s):  
Carlos Ossenbach ◽  
Rudolf Jenny
Keyword(s):  
South America ◽  
Pacific Coast ◽  
South American ◽  
History Of Botany ◽  
Palabras Clave ◽  
The Pacific ◽  
History Of ◽  
Formed Part ◽  
First Time

The fourth chapter of the series about Rudolf Schlechter’s South-American orchids again presents abridged biographical information about the botanists and orchid collectors that formed part of Schlechter’s South-American network and who traveled and worked in those countries on the continent’s northern and Caribbean coasts, through Venezuela and Colombia. In the case of Colombia, we cross the isthmus of Darien and arrive for the first time on the Pacific coast of South America. As in other chapters, brief geographical and historical introductory outlines are presented for each of these countries, followed by a narrative on those orchidologists who visited the area, chronologically by the dates of their botanical collections. Keywords/Palabras clave: biography, biografía, history of botany, historia de la botánica, Orchidaceae

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