Aspects of the washout of salmonid eggs. 4. Effects of a standard mechanical shock, applied at different stage of development, upon survival and development of eggs of brown trout (Salmo trutta L.)

It is generally accepted by fish culturists that salmonid eggs are sensitive to mechanical shock and that the sensitivity varies with the stage of development of the eggs. In general, the period of greatest sensitivity is thought to occur between fertilization and ”eyeing”. However, it is reasonable to expect that, during a period (perhaps of several hours) following fertilization, sensitivity will be low because in nature during this period the eggs may be subject to some mechanical shock caused by the parent fish covering them with gravel. In 1983-4 and 1984-5 experiments were performed on brown trout (Salmo trutta L.) eggs to examine the effect of a standard mechanical shock (c. 2,500 eggs in 1983-4 and c. 8,400 eggs in 1984-5) at various stages of development upon survival to hatching and time of hatching.The results of these experiments are reported in this study.

Effects of flow regime on the young stages of salmonid fishes. Summary and conclusions based on results for 1981-1985

The main British salmonid species spawn in clean gravel in streams and rivers, many of them in the upland areas of Britain. The earliest stages of the life cycle (eggs and alevins) spend some months within the gravel of the river bed. During this period their survival rate can be strongly influenced by flow regime and by related phenomena such as movement of coarse river bed material, changes in water level and the deposition of silt. In recent years human influence upon the flow regimes of upland water courses and upon the sediment inputs to them has increased. In order to conserve and, if possible, enhance the populations of salmonid fishes a deeper understanding of the interrelationships between survival of young salmonids and flow-related phenomena is needed. The acquisition of appropriate information is the main aim of the present project, which included: Studies on silt movement and the infilling of gravel voids by fine sediments, together with initial studies on the relationship between intragravel oxygen supply rate and the survival of intragravel stages of salmonids; studies in the general field of egg washout. The latter investigated the physical background to gravel bed disruption, the examination of the physical characteristics of sites chosen for redds, dimensions of redds and burial depth of eggs relative to the size of the fish constructing the redd and a series of smaller studies on other aspects of egg washout.

Experiments on downstream movement of recently emerged trout and salmon parr in Grassholme channels, 1983-1985

A number of authors have described the manner in which young salmonids, soon after emergence from the gravel, set up and defend territories. This leads to mortality or downstream displacement of the individuals which are unable to acquire territories and is widely accepted as the main method of population regulation amongst young salmonids. In some field experiments the fish were constrained in screened reaches and the option of downstream dispersal for the surplus fry was thus excluded. In order to explore some aspects of downstream dispersal more closely under conditions which gave more control than is obtained in a natural stream, four experimental channels were set up at Grassholme reservoir in Teesdale. The report describes the results of investigations on the timing and rate of downstream movement of young brown trout (Salmo trutta L.) and Atlantic salmon (Salmo salar L.) out of experimental channels, with special reference to the effect of water velocity on the rate of ”emigration”.

Discharge and turbidity of the regulated River Tees. Variance spectrum analysis

High suspended sediment loads may be deleterious to adult salmonids and invertebrates in gravel-bedded streams. Further, the accumulation of fine material in the interstices of the gravel may have an adverse impact on the recruitment of the young stages of salmonids. It is important therefore not only to quantify the rates and degrees of silting but also to identify sediment sources and to determine both, the frequency of sediment inputs to the system and the duration of high sediment concentrations. This report explores the application of variance spectrum analysis to the isolation of sediment periodicities. For the particular river chosen for examination the method demonstrated the essentially undisturbed nature of the catchment. The regulated river chosen for examination is the River Tees in Northern England. Variance spectrum analysis was applied to a series of over 4000 paired daily turbidity and discharge readings.

Water temperature studies on the R. North Tyne after impoundment by Kielder dam. 1. General introduction and background data

This report describes the general background to the project, defines the stations from which data sets have been obtained and lists the available data. The project had the following aims: To develop a more accurate and less labour-intensive system for the collection and processing of water temperature data from a number of stations within a stream/river system, and to use the River North Tyne downstream of the Kielder impoundment as a test bed for the system. This should yield useful information on the effects of impoundment upon downstream water temperatures.

Do humor da crônica à crônica de humor

Com base no pressuposto de que o humor é um fenômeno regularmente presente em crônicas, esta tese pretende investigar as origens dessa relação. Por que motivo leitores diversos, estudiosos das Letras e do Jornalismo são categóricos nessa associação? Além disso, se o humor constitui traço marcante do gênero, como se caracterizam as estratégias que o possibilitam? Para que essas questões sejam respondidas, apresentamos a trajetória do fenômeno humorístico nas crônicas anteriores e posteriores à chegada da imprensa no Brasil. Ademais, com corpus oriundo do jornal O Globo, trabalhamos com a teoria semiolinguística do discurso, especificamente com o contrato de comunicação e com os modos de organização do texto. Nosso objetivo geral, em suma, é verificar até que ponto procedimentos discursivos vários podem explicar o funcionamento do humor em crônicas jornalísticas contemporâneas, contribuindo para que elas se tornem um ícone de sedução dos cadernos dos jornais, transmutando-se em colunas de entretenimento

Humor e ironia em João Melo

Esta dissertação pretende desenvolver um estudo sobre o humor nos contos do escritor angolano João Melo, a partir dos livros Filhos da Pátria (2001), O dia em que o Pato Donaldo comeu pela primeira vez a Margarida (2006) e O homem que não tira o palito da boca (2009). Fundamentada nas perspectivas freudiana e lacaniana a respeito dos paradoxos do humor, pretende-se, ainda, apontar o aspecto tragicômico de seus textos e o modo como a ironia, estratégia discursiva contundente em seus contos, mostra-se como a principal estratégia discursiva do humor. Intenta-se, ainda, apontar a relação entre a literatura de João Melo e o processo criativo da sublimação, identificando-a, assim, como obra de arte, por excelência. Pelo discurso poético de João Melo, revive-se a história angolana, produzindo novas metáforas, incluindo novos significados e abrindo, assim, novos caminhos. A partir da máxima Seria trágico, se não fosse cômico, a Angola de João Melo seria traumática, se não fosse desconstruída por sua literatura