1,036 research outputs found
Domoic Acid
No full texteditors, R.H. Waring, G.B. Steventon, S.C. Mitchell.; Includes bibliographical references and index.; Chapter 4. written by R. Andrew R. Tasker - Domoic acid - UPEI professor, Dept. of Biomedical Sciences.Source type: Print(0
Cytochrome oxidase subunit VI of Trypanosoma brucei is imported without a cleaved presequence and is developmentally regulated at both RNA and protein levels
No full textMitochondrial respiration in the African trypanosome undergoes dramatic developmental stage regulation. This requires co-ordinated control of components encoded by both the nuclear genome and the kinetoplast, the unusual mitochondrial genome of these parasites. As a model for understanding the co-ordination of these genomes, we have examined the regulation and mitochondrial import of a nuclear-encoded component of the cytochrome oxidase complex, cytochrome oxidase subunit VI (COXVI). By generating transgenic trypanosomes expressing intact or mutant forms of this protein, we demonstrate that COXVI is not imported using a conventional cleaved presequence and show that sequences at the N-terminus of the protein are necessary for correct mitochondrial sorting. Analyses of endogenous and transgenic COXVI mRNA and protein expression in parasites undergoing developmental stage differentiation demonstrates a temporal order of control involving regulation in the abundance of, first, mRNA and then protein. This represents the first dissection of the regulation and import of a nuclear-encoded protein into the cytochrome oxidase complex in these organisms, which were among the earliest eukaryotes to possess a mitochondrion
Fracture toughness and compressive properties of cancellous bone at the head of the femur and relationships to non-invasive skeletal assessment measurements
No full textOsteoporosis defines a causal relationship between reduced bone density, reduced mechanical competence of the bone tissue of the sufferers and concomitantly an increased risk of fracture in life. The aims of the present study is: (1) to provide further evidence to support the use of Quantitative Ultrasound (QUS) results from peripheral sites to provide a prediction of the density of the proximal femur; and (2) to provide rational evidence for the well-proven ability of QUS to predict directly ‘risk of fracture’. 20 femoral heads were obtained from 15 Caucasian females and 5 Caucasian males undergoing emergency surgery for a fractured neck of femur. QUS investigations of the calcaneus, proximal phalanx, distal radius and mid-shaft tibia were undertaken on the donors with 72 h of surgery. 128 fracture toughness samples and 20 compression cores were manufactured and tested. Significant relationships were found between QUS parameters determined in vivo and the apparent density (g/cm3) of the tissue at the proximal femur and both the fracture toughness and strength determined in vitro from the same donor individual. In this study we relate QUS results obtained in vivo to the actual apparent density of bone tissue from the proximal femur, donated by the same individual, and the fracture toughness and compressive strength. The study demonstrates the ability of QUS investigations at peripheral sites to accurately predict the density of bone from the proximal femur and provides evidence to support the use of QUS to predict the ‘risk of fracture’ directly.<br/
Using peripheral quantitative ultrasound to predict fracture mechanics and compressive properties at the head of the femur
No full textDiets of seabirds and consequences of changes in food supply
No full textResearch conducted by members of the Working Group on Seabird Ecology, on issues most likely to be raised within the ICES community concerning the foraging ecology of seabirds and waders, and the potential interactions between these groups of birds and fisheries.
A review of issues related to seabird consumption of fish and shellfish stocks, discards and mariculture as well as the trophic role and ecology of seabirds and waders: G. L. Hunt, W. A. Montevecchi, and M. F. Leopold.
Consumption of pre-recruit fish by seabirds and the possible use of this as an indicator of fish stock recruitment: S. P. R. Greenstreet, P. H. Becker, R. T. Barrett, P. Fossum, and M. F. Leopold.
Variation in prey taken by seabirds: M. L. Tasker, C. J. Camphuysen, and P.Fossum.
Evaluation of the role of discards in supporting bird populations and their effects on the species composition of seabirds in the North Sea: S. Garthe, U. Walter, M. L. Tasker, P. H. Becker, G. Chapdelaine, and R. W. Furness.
Exploration of the short-and medium-term consequences of a reduction in the amounts of fish discarded: M. L. Tasker, P. H. Becker, and G. Chapdelaine
Evidence for decadal scale variations in seabird population ecology and links with the North Atlantic oscillation: J. B. Reid, P. H. Becker, and R. W. Furness.
A review of the causes, and consequences at the population level, of mass mortalities of seabirds : C. J. Camphuysen, P. J. Wright, M. Leopold, O. Hüppop, and J. B. Reid.
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Cyclopentyl-adenosine decreases caspase-3 activity and LDH release following simulated ischemia in cerebellar granule neurons
No full textActivation of adenosine A1 receptors in vivo or in vitro, prior to simulated ischemic insults have been demonstrated to be neuroprotective. Preconditioning with A1 receptor agonists, both in vivo and in vitro, has been shown to induce neuroprotective effects against necrosis even when administered 24–72 hours before ischemic insult. This thesis examined the neuroprotective effects of the selective A1 receptor agonist, N6-cyclopentyl-adenosine (CPA), against both apoptotic and necrotic cell death following simulated ischemia in cultured rat cerebellar granule neurons. Using antibodies directed towards neuronal nuclear protein and glial fibrillary acid protein, the purity of cerebellar granule cell cultures was found to be 98.6 ± 0.4%. This indicates that the results from these experiments were likely mediated by effects of the drugs and simulated ischemia on neurons and not astrocytes. To determine if the neuroprotection induced by CPA treatment was mediated by activation of A1 receptors, a concentration response curve for DPCPX was generated in the presence and absence of 1μM CPA. (Abstract shortened by UMI.).Source: Masters Abstracts International, Volume: 42-02, page: 0538.Advisers: Marva I. Sweeney-Nixon; Andrew Tasker
Resolution of paraneoplastic alopecia following surgical removal of a pancreatic carcinoma in a cat
No full textA 13-year-old female neutered domestic longhaired cat was presented with a five-month history of progressive weight loss and bilaterally symmetrical alopecia of the ventrum, limbs and perineum. The alopecic skin had a shiny appearance and hair in the non-alopecic areas was easily epilated. Fine needle aspirate cytology of a palpable cranial abdominal mass revealed it to be of epithelial or glandular origin. A pancreatic mass was excised by left pancreatectomy during exploratory laparotomy, and histopathology and skin biopsies confirmed a diagnosis of pancreatic carcinoma with concurrent paraneoplastic alopecia. No evidence of metastases was found on liver and lymph node biopsies. At re-examination 10 weeks after surgery, the hair had fully regrown. Skin signs recurred after 18 weeks and metastatic spread of the tumour was confirmed on postmortem examination. This case confirms that paraneoplastic alopecia associated with internal malignancies is a potentially reversible process if the internal neoplasm is excised
METAL NON-METAL AND OTHER INTERFACES - THE ROLE OF IMAGE INTERACTIONS
No full textThe authors argue that many phenomena associated with metal/nonmetal interfaces and similar situations with a large dielectric constant mismatch can be understood in terms of the image interactions due to charges in the nonmetal. The effects are additional to the traditional interactions, and are especially significant when no reactions between the phases occur. The image-charge concept allows one to rationalise much apparently unrelated information concerning: (a) the systematics of wetting and nonwetting of oxides by liquid metals; (b) the systematics of strong metal-support interaction in catalysis; (c) the spatial variation of stoichiometry in oxides grown on metals; (d) the dependence on thickness of the observed changes in the wetting by water of oxide grown on silicon; (e) some features of radiation-enhanced adhesion; and (f) a number of correlations of behaviour with nonmetal properties in which the precise choice of metal is not critical
English translation (part 3) of Zheng M and Min T, Buxaceae, (1980) in Flora Reipublicae Popularis Sinicae: Tomus 45(1). Beijing: Science Press
No full textIn the January 1991 issue of 'The Boxwood Bulletin', the ABS presented Part I of a reproduction of an important addition to the taxonomic literature on 'Buxus', entitled 'Flora: Reipublicae Popularis Sinicae'. Part II appeared in the April issue. The following pages present the third and final installment. The 'Buxus' species of East Asia and the neotropical, Central American species have long been in need of review and examination. The publication documents the work of M. Cheng, who in 1980 published a flora of the East Asian 'Buxus' species and varieties. It contains taxonomic descriptions of many species and varieties of boxwood found in China, and was translated from the Chinese by two British-born women, Isabel Tasker and Robyn Carter. They have constructed an accurate Chinese-to-English translation which has allowed the English-speaking community to review this major Asian 'Buxus' flora. The work has resulted in documenting new varieties and reclassification of other species and varieties. To laymen, reclassifications result in the most confusion. The binomial change of Korean boxwood from 'B. microphylla' var. 'insularis' to 'B. sinica' var. 'insularis' is particularly significant because it is a well-known temperate species
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