Investigations on saprolegniosis. II. Study on the process of penetrations showing evidence of a proteolytic enzyme and histopathological aspects [Translation from: Riv.ital.Piscicolt.Ittiopatol. 11(4), 109-117, 1976]

The study of enzymatic activity is of great importance in the immunology of fungi. Indeed, knowledge of biological activity of antigenic structures is important for the elucidation of host-parasite relations as well as in the search for a taxonomic factor permitting differential diagnoses. The authors used Saprolegnia cultures to analyse soluble antigenic fractions arising from the mycelium of cultures of 4 species of Saprolegnia, which are found most frequently in the parasitic state on fish: S. parasitica, S. ferax, S. delica, S. diclina. The authors conclude that in the study of saprolegniasis, the enzymatic approach affords new elements for the examination of the etiology of fungi as well as an element of gravity concerning the biochemical modifications necessary to the change of saprophytism to parasitism.

Aspects of the washout of salmonid eggs. 1. Observations on the physical characteristics of real and artificial eggs, their rate of fall in a water column and their pattern of settlement in an experimental channel

When salmonid redds are disrupted by spates, the displaced eggs will drift downstream. The mean distance of travel, the types of locations in which the eggs resettle and the depth of reburial of displaced eggs are not known. Investigation of these topics under field conditions presents considerable practical problems, though the use of artificial eggs might help to overcome some of them. Attempts to assess the similarities and/or differences in performance between real and artificial eggs are essential before artificial eggs can validly be used to simulate real eggs. The present report first compares the two types of egg in terms of their measurable physical characteristics (e.g. dimensions and density). The rate at which eggs fall in still water will relate to the rate at which they are likely to resettle in flowing water in the field. As the rate of fall will be influenced by a number of additional factors (e.g. shape and surface texture) which are not easily measured directly, the rates of fall of the two types of egg have been compared directly under controlled conditions. Finally, comparisons of the pattern of settlement of the two types of egg in flowing water in an experimental channel have been made. Although the work was primarily aimed at testing the value of artificial eggs as a simulation of real eggs, several side issues more directly concerned with the properties of real eggs and the likely distance of drift in natural streams have also been explored. This is the first of three reports made on this topic by the author in 1984.

Aspects of the washout of salmonid eggs. 2. Effects of drifting on development and survival of eggs of brown trout (Salmo trutta L.)

At high stream discharges salmonid eggs can he displaced from the gravel and may drift downstream. It has been suggested that developing salmonid eggs may be killed by ”physical shock”, especially during the period before ”eyeing”. Similarly, a progress report by the International Pacific Salmon Fisheries Commission (1966) states that salmonid eggs are most sensitive during the period between fertilisation and blastopore closure. However, it would seem unlikely that this sensitivity actually begins at the time of fertilisation because, in nature, a period, perhaps measured in hours, must occur during which the newly-fertilised eggs are exposed to physical shock during the deposition of gravel over them as a result of the cutting activity of the female fish. The present report describes simple channel experiments designed to answer the two questions: 1. After release of eggs from the gravel, does the process of drifting downstream, which implies some physical shock through movement and impact, decrease the survival of salmonid eggs? 2. Is the survival rate-influenced by the stage of development of the eggs?

Aspects of the washout of salmonid eggs. 3. Observations on the settlement of artifical eggs in a section of natural stream channel at several different discharges

It is of value to know the approximate distance of travel at different stream discharges and/or water velocities, of salmonid eggs which have been displaced from redds by spates. This report describes studies in 20 m of stream channel upstream of the fish trap in Dubby Sike. Observations were made on the relation- ships between discharge and water depth and velocity and also on the relationships between water velocity and the settlement of artificial trout eggs. The main aim was to test the hypothesis that, at any given water velocity, eggs would drift smaller distances in a natural stream than in the experimental channels.

Crenças e conhecimento de pais e profissionais de saúde sobre desenvolvimento de crianças com síndrome de Down até dois anos de idade

Este estudo apoia-se na abordagem sociocultural, em uma perspectiva interacionista da relação biologia cultura, beneficiando-se também do olhar da psicologia evolucionista para os fenômenos humanos. Estas abordagens, a partir de uma visão do homem como biologicamente cultural fazem-se relevantes para o estudo de crenças e conhecimento sobre o desenvolvimento de crianças com síndrome de Down (SD). Esta síndrome tem prevalência de um a cada 700 nascimentos, não importando classe social, racial ou local de nascimento dos pais, ou seja, é universal. A revisão da literatura revelou uma carência de estudos psicológicos sobre o contexto de desenvolvimento dessas crianças, inclusive as crenças de seus cuidadores e de profissionais de saúde. Sendo assim, o objetivo desse trabalho foi investigar crenças e conhecimento de dois grupos (pais e profissionais de saúde) sobre o desenvolvimento de crianças com síndrome de Down até dois anos de idade no Estado do Rio de Janeiro. Participaram da pesquisa 101 pessoas sendo 60 pais com filhos de até oito anos com síndrome de Down e 41 profissionais de saúde, médicos ou residentes do Instituto Fernandes Figueira, IFF/Fiocruz. Foram utilizados os seguintes instrumentos: Questionário com duas perguntas abertas sobre crenças sobre síndrome de Down que foram respondidas livremente pelos participantes; inventário sobre concepção de desenvolvimento infantil (ICDI); inventário sobre conhecimento de desenvolvimento infantil (KIDI) modificado, adaptado para crianças com síndrome de Down. Os dados foram analisados em aspectos qualitativos e quantitativos. A aplicação dos instrumentos foi realizada individualmente, em local conveniente para o participante ou no IFF/Fiocruz e após a assinatura do termo de consentimento. Os dados dos três instrumentos foram tratados e reduzidos. As respostas ao instrumento de crenças foram organizadas em categorias e comparadas. Escores nas diferentes subescalas do ICDI foram calculados e, em cada grupo (pais e profissionais) analisaram-se as concepções sobre desenvolvimento predominantes, estabelecendo-se comparações entre eles. Escores nas diferentes partes do KIDI foram ainda calculados (porcentagem de acertos). Foram feitas comparações intra e entre grupos. Os resultados foram tratados em cada um dos aspectos: crenças sobre SD, concepções e conhecimento sobre desenvolvimento. Os resultados obtidos mostram que as crenças dos pais estão distribuídas em oito categorias com três focos distintos (na criança, nos pais ou nos dois) e a dos profissionais em nove categorias, também, com três focos distintos (na SD, no médico e na criança e família). O resultado obtido no ICDI indica que os participantes valorizam mais as concepções de aprendizagem e interacionismo do que de maturação e que não há diferença significativa entre os grupos. Para o KIDI observou-se diferença significativa entre os grupos tanto no resultado geral de percentual de acertos como nos resultados em cada subescala. Espera-se que os resultados obtidos possam contribuir para a literatura sobre psicologia do desenvolvimento e síndrome de Down.

Physiological aspects of the life cycle of the river lamprey, Lampetra fluviatilis L

The life cycle of the river lamprey, L. fluviatilis, is reviewed. The larval lamprey, or ammocoete, is a blind, filter-feeding animal, which normally lies concealed in the silt deposits of streams and rivers. After a period of 3-5 years in fresh water the ammocoete undergoes a metamorphosis in the summer months into a sexually immature, non-feeding stage known as the macrophthalia, which is active. This stage migrates downstream in late winter. It adopts a parasitic existence, in intertidal areas. After 18 months it returns to spawn in fresh water, after a final freshwater stage lasting up to 9 months. The river lamprey dies within a few days after the spawning period of 3-4 weeks, and none survive to spawn the following year.

Aspects of the biology of coarse fish in the Dorset Stour

Some of the results from an investigation of five species of coarse fish, in the Stour River, carried out from 1968-1978 are presented in this article. The species involved were: Rutilus rutilis, Leuciscus leuciscus, L. cephalus, Esox lucius and Perca fluviatilis : which are of particular interest to anglers. Although these species show some similarities, as in the shape of the annual and seasonal growth curves, in most other respects each species occupies a distinct niche in the ecosystem and has a life-history strategy peculiar to itself. In this study only 5 species were investigated. When all the species present are considered the relationships or diversities suggested here will therefore be made far more complex.

Aspects of the washout of salmonid eggs. 6. Information on gravel composition , redd sites, the dimensions of redds and the depth of egg burial

Sampling was concentrated on the North Moor region and the series of ditches which drained this area to the Bristol Channel. Although most ditches were not deep the mud substratum precluded sampling from within the habitat. All samples were taken with a pond net from the banks. Efforts were made to sample each part of the habitat although in some ditches the macrophyte growth was so intense as to make sampling difficult particularly of the sediments. Organisms were identified on the 10 sampling sites.

Aspects of the washout of salmonid eggs. 5. Attempts to assess the importance of washout as a cause of mortailty

The paper reviews the methodology of attempts to assess the importance of washout as a cause of loss of salmonid eggs and alevins. The results of this study are presented of various small-scale field trials using buried artificial salmonid eggs and tethered table tennis balls. The results suggested that, even when few eggs were actually lost by washout, some downstream movement of the upper layers of gravel and of artificial eggs might have taken place.

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.