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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Studies on the Effects of Phenothiazine, In Vitro, on Heterakis Gallinae.

Oliver, W.T. January 1953 (has links)
Phenothiazine has been known to the dye industry since 1883, when Bernthsen (5, 6) first synthesized it and subsequently investigated its chemistry. The realization that the drug may have biological applications came with the publication by Campbell et al (8) in 1934 of its lethal action on culicine larvae. Knipling (59), in 1938, reported that by feeding it to cattle, the development of horn fly larvae in the faeces was completely inhibited for three days. [...]
22

Life history, non-specificity and revision of the genus Chorioptes, a parasitic mite of herbivores.

Sweatman, Gordon. K. January 1957 (has links)
Mange, scabies or acariasis is a dermatitis associated with various species of mites on domestic herbivores and other animals. One species on cattle is Chorioptes bovis (Héring, 1845) Gervais and Van Beneden, 1859. This mite has been incriminated as the cause of most clinical cases of mange reported in Canada during the past 20 years, although a few outbreaks of psoroptic, sarcoptic and demodectic acariasis were noted also. The last three kinds of mange are often severe and sometimes generalized, but chorioptic mange is generally mild and frequently restricted to small patches on the hind quarters.
23

The effects of some halogen compounds on the viability of the eggs of sclerostomes found in horses.

Cohen, Harry. January 1949 (has links)
The Sclerostomes, also known as Redworms and Palisade Worms, belong to the large group of parasitic bursate nematodes provided with a terminal buccal capsule and armed with one or more fringes of cuticle called “leaf -crowns”. They are found universally in horses and other equines, where they may cause serious diseases. The most important genera, from the standpoint of their prevalence in horses, are Strongylus, Triodontophorus, and Trichonema, the latter being generally known as the Cylicostomes. Other genera of the Family Strongylidae which comprise part of the Sclerostome grouping are Craterostomum, Oesophagodontus, and Gyalocephalus. There are approximately fifty different species of Sclerostomes known to be found in horses and other equines, but up to the present time it has been impossible to distinguish between them from the examination of the eggs alone, Theiler (1923), Taylor (1933), Cornils (1935), Kopirin (1941), and Hummelinck (1946a). Some degree of differentiation has been accomplished by means of the freeliving larvae, Albrecht (1933), Lucker (1936) and (1938), and Hummelinck (1947). The general description that Taylor (1933) gave for the life cycle of Strongylus edentatus may be applied to all of the Sclerostomes and their related groups. “The life cycle in general outline is the same for all species but is identical for none”, Cameron and Parnell (1939). The adult females, found in the colon of the host, lay eggs which reach the ground [...]
24

Studies of Heterakis Gallinae (Gmelin, 1790) Freeborn, 1923, a nematode vector of enterohepatitis of turkeys.

Connell, R. W. January 1949 (has links)
The story of blackhead, insofar as scientists have deciphered its perplexing problems, is that of a unique relationship existing between a number of avian hosts, a protozoan parasite and a parasitic nematode vector. Blackhead is acknowledged to be economically the most important disease of turkeys, having forced the abandonment of turkey rearing in many parts. Fortunately, in other susceptible species of birds, the disease seldom causes serious losses. In the caeca of the chicken, and perhaps,too, in the caeca of other susceptible birds, the blackhead organism, Histomonas meleagrldis, lives and multiplies without producing clinical disease except on rare occasions. Another inhabitant of the caeca is the worm, Heterakis gallinae, which picks up Histomonas, serving as vector host of blackhead by virtue of the fact that Histomonas becomes incorporated in its eggs. It is not known how Histomonas gets into the caecal worm egg or what form the egg-borne stage of the parasite takes. There is overwhelming evidence to show that it is there, however, because when the eggs of the worms from birds carrying blackhead are embryonated and fed to susceptible turkeys, the latter develop clinical blackhead. The work leading to the discovery of the above facts, and of others relating to the subject are considered in the historical review. H. gallinae does not always carry the organism that initiates blackhead.[...]
25

Morphological and life history studies on Entamoeba terrapinae and its comparative morphology with E. histolytica and E. invadens.

McMorran, Arlene Rae. January 1952 (has links)
The genus Entamoeba, Casagrandi and Barbagallo 1895, includes a number of species parasitic on a wide range of animals from ciliates to man. Many of these are morphologically similar but differ in growth requirements and hosts. Entamoeba histobtica, Sohaudinn 1903, in man, and Entamoeba invadens, Rodhain 1934, in snakes, are the only two species known to invade host tissue. In 1930 Sanders and Cleveland described a new species, Entamoeba terrapinae, from the terrapin, Chrysemys elegans. Since then no further work has been pablished on this amoeba, and much information regarding it is still wanting. According to Sanders and Cleveland the life-cycle of E. terrapinae differs from any other life history of a parasitic amoeba heretofore described. As their observations have not been confirmed it was deemed advisable to reinvestigate the life-cycle of this parasite. A number of species of parasitic amoebae have been described in turtles by various workers. In many of these the specific identity, which was established on inadequate morphological study, is still in doubt. In some cases size alone was the characteristic used for differentiating a species. In the present investigation a detailed study of the morphology of Entamoeba terrapinae has been made. In an attempt to evaluate morphological characteristics and size as taxonomic characters a comparison of the morphology of Entamoeba terrapinae with that of two morphologically similar species [...]
26

Studies on parasites and diseases of marine and anadromous fish from the Canadian Pacific coast.

Margolis, L. January 1952 (has links)
The parasites of marine and anadromous fish occurring in Canada’s Pacific waters, their economic importance, pathological significance and host and geographical distribution have not been studied intensively. This becomes more apparent when one considers the number of species of fish inhabiting this area (245 listed in Clemens and Wilby’s “Fishes of the Pacifie Coast of Canada” 1949) and the relatively few species (thirty-one) and individuals of the species, and restricted areas which have been investigated for parasites. The only area in which fish have been subjected to parasitological studies is the Strait of Georgia. Again when the extensive investigations of parasites of fish found in European waters, in the North American Atlantic, in Japan and other localities are brought to one’s attention, it is evident that we must know little concerning the parasitic fauna of Canadian Pacific fish and the distribution of these parasites. Parasitological investigations of fish in the neighbouring United States and Alaskan Pacific no doubt contribute to our knowledge of what we might expect in the way of parasites in fish from the coastal waters of British Columbia, as most of the species of fish occurring in Canadian waters have a distribution range from Alaska to California. Studies of this nature have been more frequent in the United States than in Canada, but the parasitic fauna can still be considered as largely unknown. [...]
27

Serological Tests in Canadian Hydatid Disease.

Nommik, Salme. January 1957 (has links)
Hydatid disease has been known since the early days of medicine and is widely distributed throughout the world. It is prevalent in South America, Iceland, Australia, New Zealand and is frequently encountered in regions along the Mediterranean Sea, in Central Europe, Russia and South Africa. Infection in the native-born population of North America has been considered to occur rarely.
28

Studies on the genus strongyloides in lower primates.

Premvati, * January 1958 (has links)
The genus Strongyloides is a common genus of nematodes parasitic in numerous animals, including man. It is unusual in its life cycle in that it is parthenogenetic in its parasitic phase and normally has a bisexual generation outside of the host, thereby increasing the number of potential infective larvae. In addition, however, the bisexual generation may be omitted when the larvae developing from the eggs of the parthenogenetic female develop directly into infective larvae instead of free living adults. The conditions causing these changes, in spite of extensive investigations by various workers are still largely unknown, and many problems still exist.
29

the Effects of Physical Stimuli on the Larval Stage of Terranova Decipiens (Krabbe, 1878).

Ronald, Keith. January 1958 (has links)
In eastern Canada, the marine fishing industry is based upon the capture, processing, and distribution of groundfish stocks. The areas fished are ideal for the reproduction of the economically important species such as the gadids and the pleuronectids. The presence of a partially enclosed body of water, such as the Gulf of St. Lawrence is also ideal for the capture of the mature fish. The ice factor encountered in a climate of such extremes forms an interesting, enforced, natural means of conserving the younger stock by limiting the duration of the fishing season. [...]
30

A taxonomic study of eye worms (Thelaziidae) from Brazilian birds.

Strachan, Alison. A. January 1954 (has links)
This study embodies the taxonomic aspects of the Thelaziidae (Eye worms) from a collection of Brazilian birds. These small threadlike worms approximately half an inch long, inhabit various sites of the eye. Some were found in the orbit of the eye, under the nictitating membrane, in the conjunctional sac or free in the eye. The pathogenic effect of these nematodes in game birds has not yet been studied; the number of worms vary from few to many in each eye, and apparently their presence in the host's eyes cause no inconvenience. However, it seems that considerable irritation of the ocular membranes would be produced by the movements of these worms.

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