975 research outputs found
âNew wine in old bottlesâ: replicating alchemical experiments
An influential strand of English alchemy was the pursuit of the âvegetable stone,â a medicinal elixir popularized by George Ripley (d. ca. 1490), made from a metallic substance, âsericon.â Yet the identity of sericon was not fixed, undergoing radical reinterpretation between the fifteenth and seventeenth centuries as Ripleyâs lead-based practice was eclipsed by new methods, notably the antimonial approach of George Starkey (1628â65). Tracing âsericonianâ alchemy over 250 years, I show how alchemists fed their practical findings back into textual accounts, creating a âfeedback loopâ in which the authority of past adepts was maintained by exegetical manipulationsâa process that I term âpractical exegesis.
The flexibility of the erythrocyte and the rate of sickling of cells containing haemoglobin
Imperial Users onl
Imported malaria: key messages in an era of elimination.
Despite concerted efforts to eliminate malaria, it remains a major global cause of morbidity and mortality with over 200 million annual cases. Significant gains have been made, with the annual global malaria incidence and mortality halving over the past twenty years, using tools such as long-lasting insecticide-treated bed nets and artemisinin-based therapies. Malaria is also a significant cause of life-threatening imported infection in the UK. It is vital for front line clinical staff involved in the assessment of acutely ill patients to be aware of the need for early diagnostic testing, malaria epidemiology, markers of severe infection and developments in antimalarial treatments to optimise patient management. The difference between a good and poor outcome is early diagnosis and treatment. Many of the challenges faced in the quest for global eradication, such as availability of appropriate diagnostic tests, and drug and insecticide resistance could also have future implications for imported malaria
Contemporary sediment dynamics and Holocene evolution of Hamford Water, Essex, England.
Contemporary sediment transport, suspended sediment flux, rates of intertidal
sedimentation, and Holocene sedimentation history are assessed for Hamford Water, a
small meso-tidal inlet and saltmarsh embayment in Essex, UK. Sediment transport rates
are calculated using semi-empirical equations; suspended sediment flux is computed by
integration of suspended sediment concentration and velocity across the inlet throat;
intertidal sedimentation rates are assessed from monitoring of discrete markers on
saltmarsh and mudflat; and Holocene sedimentation is estimated from radiocarbon
dating of buried organic layers, sampled using a vibrocorer.
Results show a tidal regime typical of ebb-dominated inlets: moderate, ebb-dominant
flow (==1 m S¡l) in the central ebb channel is matched by similar flood-dominant
marginal channel flows. The sediment dynamics are not influenced by any fluvial
input; there is negligible fresh water input. The net direction of sediment transport is
predominantly ebb-orientated. Coarse sand transport pathways are circulatory and
dependent on longshore drift. Sand (D = 0.25 mm) enters at the margins and is expelled
in the central ebb channel. Negligible sand is transported further landward than the
mouth; intertidal sedimentation relies mainly on levels of suspended sediment. Rates of
intertidal sedimentation are spatially variable: tidal creek sedimentation is greater than
saltmarsh, with a mean rate of 4.2mm yr"l. Buried organic horizons. radiocarbon dated
to 600 years BP, are attributed to reclaimed land levels. Holocene sedimentation rates
since 4300 years BP, estimated from 14C dating of shell bands. accord with current
estimates of sea-level rise of approximately 1 mm i 1
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The role and evolution of the inlet entrance and ebb tidal delta are seen as critical to the
evolution of the embayment as a whole. The interaction of the embayment with the
adjacent coastal zone considered essential when fonnulating shoreline management
plans. Hamford Water is considered an integral part of the Stour/OrwelllNaze coastal
system
The Influence of Institutional Shareholders on the Corporate Governance Practices and Financial Performance of Australian Public Listed Companies
Corporate governance has evolved out of the need for regulation of corporations. The prime motivation of this dissertation is to evaluate the current levels of voluntary disclosure compliance and financial performance of selected Australian Stock Exchange listed public companies in Australia, in terms of control by predominately non-institutional or institutional dominated organisations. The research source data for the above mentioned objective is drawn randomly from the ASX list of public companies as at May 5 2005. This dissertation draws together data which highlights entities that are controlled by an institutionally dominated shareholder base directs the board of directors to adopt a transparent approach to disclosure compliance under the current ASX CGC Principles and Guidelines regime which is predominately voluntary, with the exception of the establishment of an audit committee for those reporting entities as per ASX listing rule 12.7. Data collated is sorted and analysed to summarise the position of the data as against the stated hypotheses. The data is tempered in part and reinforced in other areas by not only domestic but also global influences and considerations. Corporate governance compliance is viewed as a window to not only shareholders of an entity but also the wider stakeholder base and the community at large. The wider base is encompassed by a theory termed enterprise governance, which is becoming increasingly recognised as a more relevant theoretical and practical strand of governance to accommodate and deal with the complexities of modem business. The collated data is presented in tables and graphical depictions that statistically test stated hypotheses and draw conclusions, and finally there is reference to possible areas of further study that can be potentially undertaken to expand the breadth of already accumulated knowledge in this area. The area being a relatively recent inclusion in Australian corporate history largely has its beginnings from international sources but is constantly being influenced and as by domestic as well international forces and considerations
The presence of Y674/Y675 phosphorylated NTRK1 via TP53 repression of PTPN6 expression as a potential prognostic marker in neuroblastoma
The tumor suppressor TP53 promotes nerve growth factor receptor (NTRK1) -Y674/Y675 phosphorylation (NTRK1-pY674/pY675) via repression of the NTRK1 phosphatase PTPN6 in a ligand-independent manner, resulting in suppression of breast cancer cell proliferation. Moreover, NTRK1-pY674/pY675 together with low levels of PTPN6 and TP53 expression is associated with favorable disease-free survival of breast cancer patients. We determined whether in neuroblastoma this protein expression pattern impacts relapse-free survival (RFS). NTRK1-pY674/pY675, PTPN6, and TP53 expression was assessed in 98 neuroblastoma samples by immunohistochemistry. Association between expression levels and RFS was investigated by multivariate and Kaplan-Meier analysis. Mutant or wild-type TP53 was identified by sequencing tumor DNA. Tumors expressing NTRK1-pY674/pY675 and low or undetectable levels of PTPN6 and TP53 were significantly associated with 5-year RFS (P = .014) when the dataset was stratified by MYCN amplification, segmental chromosomal abnormalities and histology. Similar results were observed with tumors expressing wild-type TP53, NTRK1-pY674/pY675 and low or undetectable levels of PTPN6. Kaplan-Meier analysis demonstrated a significant correlation (P = .004), with a 50% probability of RFS (median survival 4.73 years) when present compared with 19.51% (median survival 11.63 months) when absent. Similar results were seen with non-amplified MYCN or unfavorable/undifferentiating samples and tumors from patients aged 18 months or less. Importantly, NTRK1-pY674/pY675 is an independent predictor of improved RFS. These results strongly suggest that NTRK1-pY674/pY675 together with wild-type TP53 and undetectable or low levels of PTPN6 expression is a potential biomarker of improved RFS of neuroblastoma patients. The predictive value of NTRK1-pY674/pY675 together with wild-type TP53 and low PTPN6 expression could contribute to neuroblastoma patient prognosis
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