Newly hatched Aedes aegypti larvae were experimentally infected with controlled levels of Reesimermis nielseni and the development of the parasite was recorded. The nematode increased in length by 18-fold and in width by 16-fold during a relatively short 6 to 8-day parasitic phase. Most of the nemat...

Mermithids of three genera and species are known to parasitise North American Simuliids, and a more varied Mermithid fauna probably exists [cf. RAE/B 51, 135]. The host specificity of Mermithid parasites of Simuliids is variable, but the nematodes do not appear to infect other stream fauna. The spor...

A method of collecting postparasitic Neomesomermis flumenalis from larval Prosimulium mixtum/fuscum and Simulium venustum is described. The larval blackflies were collected by sweeping them with paint brushes from rocks into buckets of stream water. The larvae were obtained free of debris by placing...

Histochemical studies in the laboratory in Canada on field-collected larvae of Prosimulium fuscum Syme & Davies (mixtum fuscum) revealed no significant differences in the endocrine activity of larvae infected with mermithid nematodes and healthy larvae (of similar body dimensions). In the case o...

The leaves initiated at successive nodes in the heteroblastic series in Leea guineensis seedlings become progressively more complex in construction. Leaves at the first four nodes are simple and are followed by transitional forms between nodes 5 and 7. These transitional leaf forms are compound in n...

The organogenesis of floral development in the dioecious clonal tree species Rhus hirta offers an excellent model system to study gender expression in dioecious plants. Pistillate and staminate flowers from developing inflorescences were collected from Grover Island, located off the northern shore o...

We surveyed 11 forest remnants and their adjacent ponds to assess the species richness of amphibians on Prince Edward Island, Canada. By combining aquatic and terrestrial sampling methods, we detected the presence of four urodeles and five anurans in our study sites. No significant difference in spe...

Anthropogenic activities in Prince Edward Island (Canada) have created a mosaic of fragmented uneven-aged forests and agricultural and pasture lands, as well as large amounts of edge habitat. Although the mammalian fauna of the province is largely composed of small mammals, no previous study has inv...

Small mammal communities were studied in eight vegetation types of the Prince Edward Island National Park. Ten species were trapped. Shannon-Weiner index of diversity was high in Red Pine[Pinus resinosa] plantations (1.33 and 1.55) and a bog (1.47), and low for opened habitats such as a dune (0.19),...

We exposed Japanese medaka (Oryzias latipes) to environmentally relevant concentrations of azinphos-methyl, chlorothalonil, endosulfan, and mixtures of all three to determine if combinations of these pesticides result in additive, less-than-additive, or more-than-additive effects. Medaka were expose...

The developmental morphology of shoots of Thuja occidentalis L. (eastern white cedar) was investigated using scanning electron microscopy to determine the pattern of initiation of two types of leaves characteristic of higher (third and above) order branches. The shoots of eastern white cedar are bil...

Explores aspects of floral development in Philodendron grandifolium and Philodendron megalophyllum. Initiation of pistillate and staminate flowers; Morphology of the mature flowers; Function of the presence of calcium oxalate crystals; Observations of the homeotic shift between carpels and staminode...

Analyzes predictions made by previous allometric analyses of the relationship between population density and body mass. Ecological density of terrestrial mammal populations; Effect of trophic groups and body sizes of community members and the range of sizes; Energy use of herbivores, carnivores, and...

Regulation of the matrix metalloproteinases (MMPs) is crucial to regulate extracellular matrix (ECM) proteolysis which is important in metastasis. This study investigated the mechanism(s) by which three flavonoid-enriched fractions from lowbush blueberry (Vaccinium angustifolium) down-regulate MMP a...

The objective of this study was to compare the neurotoxic effects of acute malathion exposure with the potential blood coagulation effects. We administered various doses of malathion to Wistar rats by i.p. injection, and then we assessed the effects on blood coagulation screening tests and activity ...

Administration of adenosine A1 receptor agonists in vivo is neuroprotective in various stroke models. Experiments using either mixed cultures of neurons and astrocytes or brain slices, in which several cell types are present, have demonstrated that activation of A1 receptors also id protective again...

The inhibitory neuromodulator adenosine is neuroprotective against damage induced by cerebral ischemia. Its vasodilator effects add to its suitability as a possible anti-stroke agent, but also account for unwanted side effects following systemic administration of adenosine receptor agonists. ATP bre...

The destructive mechanisms associated with stroke are initiated by activation of glutamate receptors resulting in elevated intracellular Ca2+ and reactive oxygen species (ROS) formation. Three major approaches have been investigated to ameliorate ischemia-induced brain damage: (i) interfering with t...

These is debate about the mechanisms mediating adenosine release from neurons. In this study, the release of adenosine evoked by depolarizing cultured cerebellar granule neurons with 50 mM K+ was inhibited by 49 +/- 7% in Ca2+-free medium. The remaining release was blocked by dipyridamole (IC50 = 6....

Cellular mechanisms, both destructive and protective, that are associated with cerebral ischemia are reviewed in this paper. Central to understanding the evolution of stroke are the concepts of ischemic core and surrounding penumbral region damage, delayed neuronal death, and neuronal rescue. The ro...

We have investigated the potential role of a bi-directional nucleoside carrier in the release of endogenous adenosine from spinal cord synaptosomes by examining the effects of dipyridamole and nitrobenzylthioinosine (NBI) on evoked release of adenosine. When 40 pmol adenosine were added to synaptoso...