30 research outputs found
The Long Night
From The Sea Birds Are Still Alive (New York: Random House, 1977)
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The Writers\u27 Forum: Toni Cade Bambara
Brief statement by Toni Cade Bambara for the Writers\u27 Forum
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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Portion size estimation in dietary assessment: a systematic review of existing tools, their strengths and limitations.
CONTEXT: Overestimation or underestimation of portion size leads to measurement error during dietary assessment. OBJECTIVE: To identify portion size estimation elements (PSEEs) and evaluate their relative efficacy in relation to dietary assessment, and assess the quality of studies validating PSEEs. DATA SELECTION AND EXTRACTION: Electronic databases, internet sites, and cross-references of published records were searched, generating 16Â 801 initial records, from which 334 records were reviewed and 542 PSEEs were identified, comprising 5% 1-dimensional tools (eg, food guides), 46% 2-dimensional tools (eg, photographic atlases), and 49% 3-dimensional tools (eg, household utensils). Out of 334 studies, 21 validated a PSEE (compared PSEE to actual food amounts) and 13 compared PSEEs with other PSEEs. CONCLUSION: Quality assessment showed that only a few validation studies were of high quality. According to the findings of validation and comparison studies, food image-based PSEEs were more accurate than food models and household utensils. Key factors to consider when selecting a PSEE include efficiency of the PSEE and its applicability to targeted settings and populations.B.A., EAR, P.P. and C.R. were supported by the Medical Research Council programme number U10596038
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Portion size estimation in dietary assessment: a systematic review of existing tools, their strengths and limitations.
Context: Over or under estimation of portion size leads to measurement error during dietary assessment. Objective: To identify portion size estimation elements (PSEEs) and evaluate their relative efficacy in relation to dietary assessment; and assess the quality of studies validating PSEEs. Data selection and extraction: Electronic databases, internet sites and cross-references of published records were searched, generating 16,801 initial records, from which 334 records were reviewed and 542 PSEEs were identified comprising: 5% one- dimensional (e.g. food guides), 46% two- dimensional (e.g. photographic atlases) and 49% three- dimensional tools (e.g. household utensils). Out of 334 studies, 21 validated a PSEE (compared PSEE to actual food amounts) and 13 compared PSEEs against other PSEEs. Conclusion: Quality assessment showed that only a few validation studies were of high quality. According to the findings of validation and comparison studies, food image-based PSEEs were more accurate compared to food models and household utensils. Key factors to consider when selecting a PSEE include efficiency of the PSEE and its applicability to targeted settings and populations.B.A., EAR, P.P. and C.R. were supported by the Medical Research Council programme number U10596038