Browsing by Author "Rolfe, Vivien E."
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Item Metadata only Academic staff attitudes towards electronic learning in arts and sciences(2008) Rolfe, Vivien E.; Alcocer, M.; Bentley, E.; Milne, D.; Meyer-Sahling, J.Item Open Access Are multimedia resources effective in life science education? A meta-analysis.(UK Centre for Bioscience, 2011-11) Rolfe, Vivien E.; Gray, Douglas T.Multimedia learning is widely used in life science education where the use of pictures and text can bring complex structures and processes to life. However the impact on academic performance and deeper understanding is not well documented. We therefore carried out a systematic review to evaluate the effectiveness of multimedia resources in tertiary level life science education. Comprehensive literature searches were conducted; studies were selected based on stringent pre-set criteria, and data were extracted for meta-analysis. In total, 17 studies were used in the meta-analyses with a total population of 2,290 students. The results show that, when used as a substitute for laboratory practicals, multimedia improved student learning gains assessed with an end-of-year examination, (mean difference 7.06, ±4.61). Although it did not improve short-term learning gains in this scenario, multimedia improved learning gains in 10 of the 16 sub-group comparisons made across all the studies. Overall, multimedia learning was more effective than many traditional educational methods although the numbers of studies included in the analysis were ultimately considered to be small due to many exclusions from the studies included in the analysis. Therefore, more good quality trials are required to evaluate a broader range of scenarios relevant to modern practices. Studies would benefit from being rigorous in design with good quality reporting of all aspects of methodology and study results.Item Open Access Building External Partnerships to Enhance STEM Education Opportunities(HEA, 2012-04-11) Rolfe, Vivien E.; Fowler, Mark R.Item Metadata only Can Turnitin be used to provide instant formative feedback?(Wiley, 2011) Rolfe, Vivien E.Item Metadata only Colonic fluid and electrolyte transport in health and disease.(Veterinary Clinics of North America., 1999) Rolfe, Vivien E.major function of the mammalian colon is the absorption of water and electrolytes from the luminal contents that enter through the ileocecal valve. The absorptive capacity of the colon is influenced by the rate of passage of the luminal contents. To maximize the efficiency of these processes, there is close coordination between motility and absorptive functions. A balance between the benefits of prolonged time of contact between the colonic mucosa and the luminal contents and the adverse effects of accumulated toxic and carcinogenic metabolites is essential.Item Metadata only Engaging; Employers, Porfessional Bodies and OER(2012) Fowler, Mark R.; Rolfe, Vivien E.Item Metadata only Enterotoxin Escherichia coli STa activates a nitric oxide-dependent myenteric plexus secretory reflex in the rat ileum.(Journal of Physiology, 1994) Rolfe, Vivien E.; Levin, Roy J.Mucosally added enterotoxin Escherichia coli STa increased the electrogenic Cl- secretion measured as the short-circuit current (Isc) across isolated muscle-stripped and muscle-unstripped rat mid-ilea incubated in vitro. 2. Pretreatment with serosal L-NAME (N omega-nitro-L-arginine methyl ester) or tetrodotoxin (TTX) significantly reduced the maximum Isc and the duration of action of STa in the unstripped but not stripped ilea. D-NAME (serosal), indomethacin or 5-hydroxy-tryptamine-desensitization was ineffective on STa-induced Isc in either stripped or unstripped ilea. 3. Serosal capsaicin reduced the maximum Isc of STa and its duration of action in unstripped ilea. 4. L-Arginine induced a significantly larger increase in the Isc across unstripped ilea than across stripped ilea; this could be significantly reduced by serosal L-NAME or TTX, although these were ineffective in stripped ilea. 5. Pretreatment of anaesthetized rats with I.P. L-NAME suppressed the fluid secretion induced by luminal STa in ilea in vivo but had no effect on that induced by luminal carbachol. 6. Mucosal STa increased electrogenic Cl- secretion across intact rat ileum in vitro by activating a capsaicin-sensitive, nitric oxide-dependent myenteric plexus-mediated secretory reflex. The suppression by L-NAME of STa induced ileal fluid secretion in vivo probably involves the inhibition of this reflex.Item Open Access HEA/JISC Open Educational Resources; How institutional culture can change to adopt open practices(JISC/HEA, 2012) Rolfe, Vivien E.; Fowler, Mark R.Item Metadata only Host-bacterial interactions in inflammatory bowel disease.(2004) Mahida, Y. R.; Rolfe, Vivien E.Item Metadata only Morphology and immunopathology of the small and large intestine in dogs with nonspecific dietary sensitivity.(The American Society for Nutritional Sciences, 2002) Zentek, J.; Hall, E. J.; German, A.; Haverson, K.; Bailry, M.; Rolfe, Vivien E.; Butterwick, R. F.; Day, M. J.Item Metadata only Neural and non-neural activation of electrogenic secretion by 5-hydroxytryptamine in the rat ileum in vitro.(Acta Physiologica Scandinavica., 1998) Rolfe, Vivien E.; Levin, Roy J.5-hydroxytryptamine (5-HT) stimulates electrogenic Cl−secretion in rat ileum stripped of its outer smooth musculature and myenteric plexus. The myenteric plexus, however, is a site of 5-HT synthesis in the gut, and the plexus mediates electrogenic ion secretion activated by luminal enterotoxin STa and taurocholate. Thus, we investigated the role of the myenteric plexus in 5-HT-induced electrogenic secretion in vitro by measuring short-circuit current (Isc, microamps) with voltage-clamp apparatus as an index of electrogenic Cl−secretion in rat ileum which was either stripped of the myenteric plexus or was left intact. Serosally added 5-HT stimulated electrogenic Cl−secretion in muscle-stripped and intact ileum in a concentration-dependent manner. Pre-treatment of stripped ileum with atropine (1 μm), hexamethonium (100 μm), tetrodotoxin (1.25 μm) and capsaicin (1 μm) for 15 min did not effect the maximum Isc induced by 5-HT which would implicate a direct action on the enterocyte. In intact ilea, however, tetrodotoxin (TTX) and capsaicin reduced significantly the maximum values of Isc stimulated by 5-HT, and the nitric oxide synthase inhibitor Nω-nitro- L-arginine methyl ester ( L-NAME) caused a significant decrease in the maximum response to 5-HT. These results suggest that electrogenic secretion induced by 5-HT in rat ileum in vitro occurs partly by activation of a non-neural pathway probably involving a direct interaction with the enterocyte, and partly via a nitrinergic-myenteric secretory reflex activated by sensory afferent fibres. These data highlight the danger of characterising intestinal secretory activity from in vitro experiments by using muscle-stripped tissue only.Item Metadata only Nitric oxide stimulates cyclic guanosine monophosphate production and electrogenic secretion in Caco-2 colonocytes.(Clinical Science, 1999) Rolfe, Vivien E.; Milla, Peter J.Nitric oxide stimulates intestinal ion transport via the activation of enteric nerves, but it is not known whether it regulates intestinal transport function by acting on the epithelium directly. The aim of this study was to determine the influence of nitric oxide on epithelial electrogenic ion secretion, measured as the short-circuit current (Isc), using the human colonic carcinoma cell line Caco-2. The cellular mechanisms were examined by measuring epithelial cGMP production, and nitrite release was monitored as an index of nitric oxide synthesized. The nitric oxide substrate L-arginine methyl ester increased nitrite release, electrogenic secretion and cell cGMP production. Pretreatment with L-NAME (Nw-nitro-L-arginine methyl ester, 1 mM), but not the D-isomer, significantly reduced the electrogenic secretion and cGMP production evoked by L-arginine methyl ester, implicating nitric oxide synthase involvement. Pretreatment with cystamine, but not Methylene Blue, significantly reduced the maximum Isc and the cGMP release induced by L-arginine methyl ester and the nitric oxide donor sodium nitroprusside, implicating the involvement of particulate guanylate cyclase. In conclusion, nitric oxide stimulates electrogenic ion secretion and cGMP production in intestinal epithelial cells by activating particulate guanylate cyclase. The direct action of nitric oxide on the intestinal epithelium may be important in the regulation of intestinal transport function in health and in inflammatory bowel disease.Item Metadata only Open educational resources: staff attitudes and awareness(Research in Learning Technology, 2012-02-03) Rolfe, Vivien E.Attitudes are changing in education globally to promote the open sharing of educational courses and resources. The aim of this study was to explore staff awareness and attitudes towards ‘‘open educational resources’’ (OER) as a benchmark for monitoring future progress. Faculty staff (n6) were invited to participate in semi-structured interviews that facilitated the development of a questionnaire. Staff respondents (n50) were not familiar with the term OER but had a clear notion of what it meant. They were familiar with open content repositories within the university but not externally. A culture of borrowing and sharing of resources exists between close colleagues, but not further a field, and whilst staff would obtain resources from the Internet, they were reticent to place materials there. Drivers for mobilising resources included a strong belief in open education, the ability of OER to enhance individual and institutional reputations and economic factors. Barriers to OER included confusion over copyright and lack of IT support. To conclude, there is a positive collegiate culture within the faculty, and overcoming the lack of awareness and dismantling the barriers to sharing will help advance the open educational practices, benefitting both faculty staff and the global community.Item Metadata only Probiotics for maintenance of remission in Crohn’s disease(2006) Rolfe, Vivien E.; Fortun, P. J.; Hawkey, C. J.; Bath-Hextall, F.Item Metadata only Relationship between faecal character and intestinal transit time in normal dogs and diet-sensitive dogs(British Small Animal Veterinary Association, 2006) Rolfe, Vivien E.; Batt, R. M.; Butterwick, R. F.; Adams, C. A.Item Metadata only Relationships between fecal consistency and colonic microstructure and absorptive function in dogs with and without nonspecific dietary sensitivity(American Veterinary Medical Association, 2002) Rolfe, Vivien E.; Adams, C. A.; Butterwick, R. F.; Batt, R. M.Item Metadata only Sickle cell in the university curriculum: a survey assessing demand for open access educational materials in a constructed community of interest .(Radcliffe Publishing, 2011-03) Rolfe, Vivien E.; Fowler, Mark R.; Dyson, SimonSuccessive UK governments have sought to support expanded teaching of science, technology, engineering and mathematics (STEM) subjects within university curricula. There is an increased expectation that the education of health professionals will enhance their knowledge of genetics. Sickle-cell disease is both a genetic condition and a major public health issue globally that is neglected in university curricula. An Internet survey involving 226 respondents from sickle-cell communities of interest (science educators, health professionals and voluntary groups for sickle cell) found greater awareness of educational resources on popular Internet sites than on formally constituted academic repositories for open education resources. Sickle cell was widely seen as an important topic for open education resources. These began in the USA in the 1990s but have only more recently received attention in the UK. A project developing such sickle-cell resources within a repository of open education resources has been proposed to and funded by the UK's Higher Education Academy (HEA) and Joint Information Systems Committee (JISC). From 2011, 'Sickle Cell Open: Online Topics and Education Resources (SCOOTER)' will develop sickle-cell open education resources, which can be found on its website (www.sicklecellanaemia.org).Item Metadata only Tetrahydrobiopterin regulates cyclic GMP-dependent electrogenic chloride secretion in mouse ileum in vitro.(Physiological Society, 1997) Rolfe, Vivien E.; Brand, Michael P.; Heales, Simon J. R.; Lindley, K. J.; Milla, Peter J.Basal electrogenic Cl- secretion, measured as the short-circuit current (I-SC), was variable in ileum removed from tetrahydrobiopterin (BH4)-deficient hph-1 mice and wild-type controls in vitro, although values were not significantly different.2. The basal nitrite release and mucosal cyclic guanosine 3',5'-monophosphate (cyclic GMP) production were similar in control and BH4-deficient ileum.3. Mucosally added Escherichia coli heat-stable toxin (STa, 55 ng ml(-1)) increased the nitrite release, cyclic GMP levels and the I-SC in control ileum, but its secretory actions were reduced in BH4-deficient ileum.4. L-Arginine (1 mM) increased the nitrite release, cyclic GMP production and the I-SC in control ileum, but the actions were reduced in BH4-deficient ileum.5. Serosal carbachol (1 mM) stimulated maximum short-circuit currents of similar magnitude in both control and BH4-deficient ileum, whilst nitrite release and cyclic GMP production were minimal.6. E. coli STa and L-arginine increased electrogenic Cl- secretion across intact mouse ileum in vitro by releasing nitric oxide and elevating mucosal cyclic GMP. The inhibition of these processes in the hph-1 mouse ileum suggests that BH4 may be a target for the modulation of electrogenic transport, and highlight the complexity of the interactions between nitric oxide and cyclic GMP in the gut.Item Metadata only Vagotomy inhibits the jejunal fluid secretion activated by luminal ileal Escherichia coli STa in the rat in vivo.(BMJ Publishing, 1999) Rolfe, Vivien E.; Levin, Roy J.BACKGROUND Escherichia coli heat stable enterotoxin (STa) is a major cause of secretory diarrhoea in humans. AIMS To assess the effects of instilling STa into the ileum on remote fluid secretion in the jejunum and colon in rats in vivo by a gravimetric technique. METHODS AND RESULTS Ileal STa (55 ng/ml) stimulated fluid secretion in both ileal and jejunal loops but not in the colon. The fluid secretion induced by ileal STa was inhibited by l-NAME (Nω -nitro-l-arginine methyl ester, 40 mg/kg intraperitoneally) but not by d-NAME (Nω -nitro-d-arginine methyl ester). Ileal carbachol (183 mg/ml) instilled into the lumen stimulated ileal secretion but not jejunal secretion, and was unaffected by l-NAME. Capsaicin (10 μM), instilled luminally with STa in the ileum, blocked both the ileal and jejunal fluid secretion. Acute bilateral vagotomy prevented luminal ileal STa from inducing jejunal fluid secretion but not from activating ileal fluid secretion. CONCLUSION IlealE coli STa stimulates remote secretion in the rat jejunum but not in the colon, probably by a nitrinergic, vagal reflex mediated by C fibres. This neural pathway will amplify the action of the toxin in its generation of secretory diarrhoea.Item Metadata only Why Bother with Open Education?(SCORE The Open University, 2013-03) Rolfe, Vivien E.; Fowler, Mark R.