155 research outputs found

    Is there a 'growth trap'?: a preliminary analysis of profit and revenue data for Canadian companies

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    Michael Porter (1996) has argued that managers frequently fall into a ‘growth trap’, focusing on growing revenues at the expense of a weakened strategy and reduced profits. Research by others offers mixed support for Porter’s argument. This study reports preliminary results from analyzing data on revenue and profits for two years from 1,000 large Canadian companies. It shows that the relationship between revenue and profits is weaker than one might expect, but it is a positive relationship. Thus Porter’s conclusion may be valid but only to a limited extent

    Person-Context Influences on Educational Involvement in Rural Cambodian Schools

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    Based on Bronfenbrenner’s Process-Person-Context-Time model, this study explored the attitudes and potential factors affecting children’s educational participation in two non-governmental organization-sponsored rural schools in Siem Reap, Cambodia. Focus groups and individual interviews were conducted with students (female and male), teachers, principals, and parents. A discovery-oriented qualitative analytical approach revealed that at the individual level, truancy and student respect for school regulations impacted school participation. At the family level, parental support and family difficulties influenced school participation. At the school level, teacher ability, teacher-parent interactions, and adequate resources either facilitated or hindered student success. At the socio-cultural level, socioeconomic conditions, communal supports, and traditional gendered expectations created gender disparities in school involvement. Policy implications include a nation-wide comprehensive professional development program targeting teacher training (structural level), a strong teacher-counselor partnership to facilitate the development of literacy campaigns (community level), and increasing female mentors and counselors to increase gender parity (cultural level)

    Investing in Maine Research Infrastructure: Sustainable Forest Bioproducts

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    The University of Maine, the University of Southern Maine, several baccalaureate institutions in the state, along with other federal, state and local public, private, and non-profit institutions will collaborate to create the Forest Bioproducts Research Institute (FBRI) at the University of Maine. The vision of the FBRI is to advance understanding about the scientific underpinnings, system behavior, and policy implications for the production of forest-based bioproducts that meet societal needs for materials, chemicals, and fuels in an economically and ecologically sustainable manner.The research plans Integrate three themes. They are (1) forest sustainability modeling of life cycle assessment, (2) integrated biopolymer separations and residual solids modifications, and (3) biological and chemical platform conversion technologies.The research capitalizes upon Maine\u27s unique position of having a large natural resource base, existing research capacities in pulp and paper, forestry, and wood products, along with a strong industrial presence. State, national, and global collaborations, including those with Rensselaer Polytechnic Institute and the University of Tennessee-Knoxville, will contribute broader benefits to society as a result of this investment in forestry research.The FBRI will serve as the forest-based carbohydrate economy center of excellence for the region, with a primary goal of transitioning developed science and technology to the state\u27s industrial arena. State, national, and global impacts will be realized as a result of the investment in this research. In addition, a cadre of future engineers and scientists in multidisciplinary disciplines as well as policy-makers will result from the expected collaborations. Support is provided through the NSF Experimental Program To Stimulate Competitive Research (EPSCoR)

    Assessment of the effect of phenytoin on cutaneous healing from excision of melanocytic nevi on the face and on the back

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    <p>Abstract</p> <p>Background</p> <p>Topical phenytoin is a powerful skin wounds healing and it may be useful in clinical practice. The purpose of this study was to evaluate the effect of topical phenytoin 0.5%, by comparing it with cream (control) in wounds resulting from excision of two melanocytic nevi in the same patient. Our purpose was also to assess if phenytoin had better therapeutic and cosmetic outcomes when compared with cream (control).</p> <p>Methods</p> <p>This study evaluated 100 patients with skin wounds from excision of melanocytic nevi. 50 patients with lesions on the face and 50 patients with lesions on the back, totalizing 200 lesions excised with modified punch. The resulting superficial skin wounds had the same diameter and depth, and second intention healing followed.</p> <p>Patients were followed for 60 days. Student's t-test, Mann Whitney nonparametric test, analysis of variance, LSD test, Shapiro-Wilks test and Fisher test were used to analyze the results, depending on the nature of the variables being studied.</p> <p>Results</p> <p>Phenytoin showed better therapeutic and cosmetic results, by healing faster, with more intense epithelization in wounds in comparison with cream (control). Phenytoin showed a statistically significant difference regarding the following parameters (p < 0.05): wounded area and healing time. Phenytoin application resulted in a smaller area and a shorter healing time. Also the intensity of exudates, bleeding, and the epithelization were more intense in phenytoin-treated wounds. Regarding the shape and thickness of the scar, injuries treated with phenytoin had round and flat shaped scars in most of the cases. Considering patient's gender and phototype, female patients presented smaller wounds and scar areas; and phototype I had the largest scar areas. Contact eczema was an adverse reaction in 7 injuries located on the back caused by cream (control) and hypoallergenic tape.</p> <p>Conclusions</p> <p>Phenytoin showed better therapeutic and cosmetic results compared with cream (control). Phenytoin is a low cost drug, which accelerates skin wounds healing in human patients. Trial registration: ISRCTN96539803</p

    Migraine attacks the Basal Ganglia

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    <p>Abstract</p> <p>Background</p> <p>With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month). The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human) brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF) to a matched (gender, age, age of onset and type of medication) group of patients whose migraine episodes progressed (HF).</p> <p>Results</p> <p>In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain.</p> <p>Conclusions</p> <p>Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine.</p

    Apolipoprotein E4 Exaggerates Diabetic Dyslipidemia and Atherosclerosis in Mice Lacking the LDL Receptor

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    OBJECTIVEWe investigated the differential roles of apolipoprotein E (apoE) isoforms in modulating diabetic dyslipidemia—a potential cause of the increased cardiovascular disease risk of patients with diabetes.RESEARCH DESIGN AND METHODSDiabetes was induced using streptozotocin (STZ) in human apoE3 (E3) or human apoE4 (E4) mice deficient in the LDL receptor (LDLR−/−).RESULTSDiabetic E3LDLR−/− and E4LDLR−/− mice have indistinguishable levels of plasma glucose and insulin. Despite this, diabetes increased VLDL triglycerides and LDL cholesterol in E4LDLR−/− mice twice as much as in E3LDLR−/− mice. Diabetic E4LDLR−/− mice had similar lipoprotein fractional catabolic rates compared with diabetic E3LDLR−/− mice but had larger hepatic fat stores and increased VLDL secretion. Diabetic E4LDLR−/− mice demonstrated a decreased reliance on lipid as an energy source based on indirect calorimetry. Lower phosphorylated acetyl-CoA carboxylase content and higher gene expression of fatty acid synthase in the liver indicated reduced fatty acid oxidation and increased fatty acid synthesis. E4LDLR−/− primary hepatocytes cultured in high glucose accumulated more intracellular lipid than E3LDLR−/− hepatocytes concomitant with a 60% reduction in fatty acid oxidation. Finally, the exaggerated dyslipidemia in diabetic E4LDLR−/− mice was accompanied by a dramatic increase in atherosclerosis.CONCLUSIONSApoE4 causes severe dyslipidemia and atherosclerosis independent of its interaction with LDLR in a model of STZ-induced diabetes. ApoE4-expressing livers have reduced fatty acid oxidation, which contributes to the accumulation of tissue and plasma lipids

    Arterial spin labelling MRI to measure renal perfusion: a systematic review and statement paper

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    Renal perfusion provides the driving pressure for glomerular filtration and delivers the oxygen and nutrients to fuel solute reabsorption. Renal ischaemia is a major mechanism in acute kidney injury and may promote the progression of chronic kidney disease. Thus, quantifying renal tissue perfusion is critically important for both clinicians and physiologists. Current reference techniques for assessing renal tissue perfusion have significant limitations. Arterial spin labelling (ASL) is a magnetic resonance imaging (MRI) technique that uses magnetic labelling of water in arterial blood as an endogenous tracer to generate maps of absolute regional perfusion without requiring exogenous contrast. The technique holds enormous potential for clinical use but remains restricted to research settings. This statement paper from the PARENCHIMA network briefly outlines the ASL technique and reviews renal perfusion data in 53 studies published in English through January 2018. Renal perfusion by ASL has been validated against reference methods and has good reproducibility. Renal perfusion by ASL reduces with age and excretory function. Technical advancements mean that a renal ASL study can acquire a whole kidney perfusion measurement in less than 5–10min. The short acquisition time permits combination with other MRI techniques that might inform drug mechanisms and renal physiology. The flexibility of renal ASL has yielded several variants of the technique, but there are limited data comparing these approaches. We make recommendations for acquiring and reporting renal ASL data and outline the knowledge gaps that future research should address

    Use of molecular modelling to probe the mechanism of the nucleoside transporter NupG.

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    Nucleosides play key roles in biology as precursors for salvage pathways of nucleotide synthesis. Prokaryotes import nucleosides across the cytoplasmic membrane by proton- or sodium-driven transporters belonging to the Concentrative Nucleoside Transporter (CNT) family or the Nucleoside:H(+) Symporter (NHS) family of the Major Facilitator Superfamily. The high resolution structure of a CNT from Vibrio cholerae has recently been determined, but no similar structural information is available for the NHS family. To gain a better understanding of the molecular mechanism of nucleoside transport, in the present study the structures of two conformations of the archetypical NHS transporter NupG from Escherichia coli were modelled on the inward- and outward-facing conformations of the lactose transporter LacY from E. coli, a member of the Oligosaccharide:H(+) Symporter (OHS) family. Sequence alignment of these distantly related proteins (∼ 10% sequence identity), was facilitated by comparison of the patterns of residue conservation within the NHS and OHS families. Despite the low sequence similarity, the accessibilities of endogenous and introduced cysteine residues to thiol reagents were found to be consistent with the predictions of the models, supporting their validity. For example C358, located within the predicted nucleoside binding site, was shown to be responsible for the sensitivity of NupG to inhibition by p-chloromercuribenzene sulphonate. Functional analysis of mutants in residues predicted by the models to be involved in the translocation mechanism, including Q261, E264 and N228, supported the hypothesis that they play important roles, and suggested that the transport mechanisms of NupG and LacY, while different, share common features
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