Toxin Mediated Diarrhea in the 21st Century: The Pathophysiology of Intestinal Ion Transport in the Course of ETEC, V. cholerae and Rotavirus Infection

An estimated 4 billion episodes of diarrhea occur each year. As a result, 2–3 million children and 0.5–1 million adults succumb to the consequences of this major healthcare concern. The majority of these deaths can be attributed to toxin mediated diarrhea by infectious agents, such as E. coli, V. cholerae or Rotavirus. Our understanding of the pathophysiological processes underlying these infectious diseases has notably improved over the last years. This review will focus on the cellular mechanism of action of the most common enterotoxins and the latest specific therapeutic approaches that have been developed to contain their lethal effects

The molecular organization of nerve membranes. II. Glycolytic enzymes and ATP synthesis by plasma membranes of squid retinal axons

The following glycolytic enzyme activities were demonstrated in membrane fractions isolated from squid retinal nerve: phosphoglyceric kinase, pyruvic kinase, glyceraldehyde-3-phosphate dehydrogenase, aldolase, glucose-6-phosphate dehydrogenase, and hexokinase. After two additional washings with a hypotonic solution, only two of them, glucose-6-phosphate dehydrogenase and pyruvic kinase, were solubilized. The incubation of these membranes with ADP or GDP and Pi resulted in the incorporation of Pi into the diphosphate. The reaction product was identified as ATP or GTP. No esterification was obtained with CDP or UDP as Pi acceptor. The enzyme system responsible for the synthesis of the nucleotide triphosphate was demonstrated to be membrane bound, and not due to soluble or mitochondrial contamination of the membrane fraction. The possible role of this system is discussed. © 1971

Sodium transport inhibition by selective mitochondrial inhibitors in the urinary bladder of the toad

The effects of selective mitochondrial inhibitors on the short‐circuit current and oxygen consumption displayed by the isolated urinary bladder of the toad was studied. Three types of compounds were used: (a) electron transfer inhibitors, Amytal, Cyanide and Antimycin A; (b) energy transfer inhibitors Guanidine, Oligomycin and Rutamycin; and (c) uncoupling agents, Carbonyl cyanide m‐chlorophenylhydrazone and 2–4 dinitrophenol. The kinetics of inhibition of oxygen consumption indicated that the inhibitors tested were effectively reaching the mitochondria of the bladder cells. Different kinetics of inhibition of short‐circuit current were obtained with the various inhibitors tested. Uncouplers and electron transfer inhibitors rapidly blocked the short‐circuit current; energy transfer inhibitors only produced a slow and partial inhibition. A site of energy‐coupling, tentatively identified with the intermediate formed in the energy transfer reactions closest to the electron transfer chain

Modeling Both the Space and Place of Coastal Environments: Exploring an Approach for Developing Realistic Geovisualizations of Coastal Places

Effective coastal planning incorporates the variety of user needs, values, and interests associated with coastal environments. This requires understanding how people relate to coastal environments as "places," imbued with values and meanings, and accordingly, tools that can capture place and connect with people's "sense of place" have the potential for supporting effective coastal management strategies. Realistic, immersive geographical visualizations, i.e., geovisualizations, theoretically hold potential to serve such a role in coastal planning; however, significant research gaps exist around this application context. Firstly, place theory and geovisualizations are rarely explicitly linked in the same studies, leaving questions around how to model "coastal place," as well as coastal space. Secondly, geovisualization work has focused on terrestrial environments, and research on how to realistically model coastal places is currently in its infancy. The current study addresses the research gaps by developing a coastal geovisualization under place-based considerations, and then examining its capacity as a tool for connecting with people's sense of place. The research uses Sidney Spit in the Gulf Islands National Park Reserve (BC, Canada) as a study site, and a geovisualization was developed using a combination of ArcGIS, Adobe Photoshop, Trimble SketchUp, and Unity3D. Focus groups were assembled involving Parks Canada staff and Greater Victoria Area residents, and the geovisualization was assessed in terms of its representation of a real-world coastal place and ability for connecting with sense of place. Findings from the study indicate that the presence of certain elements in coastal geovisualizations can contribute to realism and sense of place, such as people, dogs, birds, marine life, vegetation, and boats; however, simultaneously, deficiencies in numbers and varieties of these elements can detract from realism and sense of place. In addition, incorporation of soundscape and viewshed elements both demonstrated as significant to the tool's ability to connect with sense of place, with the latter potentially being more significant among those with higher familiarity with the real-world place. Beach textures were also found to be important for the geovisualization's ability to connect with sense of place; however, this ability can be compromised when running versions of the tool with lower graphical resolution