958 research outputs found

    Investigation of electrometric methods for the estimation of copper

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    The previous work on this subject, is considered, showing that no satisfactory methods have so far been produced. The application of monometallic electrode systems to precipitation and oxidation and reduction reactions and the method of conducting titrations are discussed. Bimetallic electrode systems are considered with special reference to a new method due to Foulk and Bawden. The following methods have been Investigated: (1) The precipitation of cuprous thiocyanate from a copper sulphate solution reduced by bisulphite (Muller and Rudolph's method) was found to be too easily influenced by the bisulphite concentration, time of titration and temperature to be practicable. (2) The precipitation of cuprous thiocyanate by excess standard potassium thiocyanate solution and back-titration with silver nitrate was found to give excellent results with copper sulphate concentrations greater than N/25 and in the presence of zinc and iron. (3) The reduction of copper sulphate in hydrochloric acid solution by stannous chloride gives a sharp end-point if the acid concentration is high but the results vary with this concentration and are always too high. (4) The titration of copper sulphate with sodium thiosulphate, potassium cyanide and iodide respectively. These methods are not satisfactory, no distinct end point being obtained. (5) The titration of the iodine liberated by the action of copper sulphate and potassium iodide with thiosulphate gives satisfactory end-points in acetic acid solution using a mono-metallic system of electrodes. Foulk and Bawden's method however gives far sharper end-points and is applicable to copper concentrations greater than N/250 and in the presence of many metals. Adaptations in the presence of ferric salts are discussed. Replacing thiosulphate with arsenlte solution is satisfactory with copper sulphate solutions more concentrated than N/50. Methods 3L and 5 are recommended as satisfactory. <p

    Melody and pitch processing in five musical savants with congenital blindness

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    Abstract. We examined absolute-pitch (AP) and short-term musical memory abilities of five musical savants with congenital blindness, seven musicians, and seven non-musicians with good vision and normal intelligence in two experiments. In the first, short-term memory for musical phrases was tested and the savants and musicians performed statistically indistinguishably, both signifi- cantly outperforming the non-musicians and remembering more material from the C major scale sequences than random trials. In the second experiment, participants learnt associations between four pitches and four objects using a non-verbal paradigm. This experiment approximates to testing AP ability. Low statistical power meant the savants were not statistically better than the musicians, although only the savants scored statistically higher than the non-musicians. The results are evidence for a musical module, separate from general intelligence; they also support the anecdotal reporting of AP in musical savants, which is thought to be necessary for the development of musical-savant skill

    Connecting does not necessarily mean learning: Course handbooks as mediating tools in school-university partnerships

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    This is the author's accepted manuscript (titled "Course handbooks as mediating tools in learning to teach"). The final published article is available from the link below. Copyright @ 2011 American Association of Colleges for Teacher Education.Partnerships between schools and universities in England use course handbooks to guide student teacher learning during long field experiences. Using data from a yearlong ethnographic study of a postgraduate certificate of education programme in one English university, the function of course handbooks in mediating learning in two high school subject departments (history and modern foreign languages) is analyzed. Informed by Cultural Historical Activity Theory, the analysis focuses on the handbooks as mediating tools in the school-based teacher education activity systems. Qualitative differences in the mediating functions of the handbooks-in-use are examined and this leads to a consideration of the potential of such tools for teacher learning in school–university partnerships. Following Zeichner’s call for rethinking the relationships between schools and universities, the article argues that strong structural connections between different institutional sites do not necessarily enhance student teacher learning

    Squamous cell carcinoma of the nasal cavity:A descriptive analysis of cases from the Head and Neck 5000 study

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    OBJECTIVES: This paper aims to provide contemporary epidemiological data on squamous cell carcinoma (SCC) of the nasal cavity, which represents a rare type of head and neck cancer.DESIGN, SETTING &amp; PARTICIPANTS: A descriptive analysis of people with nasal cavity SCC treated with curative intent from the Head and Neck 5000 study; a multicentre clinical cohort study of people from the UK with head and neck cancer. People with tumours of the nasopharynx, paranasal sinuses and other sub-sites of the head and neck were excluded.MAIN OUTCOME MEASURES: Demographic data and treatment details are presented for all participants. The main outcomes were overall survival and survival according to categories of characteristics (e.g. smoker vs non-smoker); these were explored using Kaplan-Meier plots.RESULTS: Thirty people with nasal cavity SCC were included in the study, of which most were male (67%) and current or ex-smokers (70%). The majority (70%) presented with early stage (T1/2, N0) tumours. Cervical lymph node metastases at presentation were rare, occurring in only one person. Nine people died during the follow up period (30%). Worse survival outcomes were seen in people with moderate or severe co-morbidities.CONCLUSIONS: This paper provides epidemiological data on nasal cavity SCC in the UK. Patterns of disease and survival outcomes are described, identifying high-risk groups. Further studies should explore whether primary treatment modality alters survival. This article is protected by copyright. All rights reserved.</p

    Disease trajectories, place and mode of death in people with head and neck cancer: findings from the ‘Head and Neck 5000’ population-based prospective clinical cohort study

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    Background: Few large studies describe initial disease trajectories and subsequent mortality in people with head and neck cancer. This is a necessary first step to identify the need for palliative care and associated services. Aim: To analyse data from the Head and Neck 5000 study to present mortality, place and mode of death within 12 months of diagnosis. Design: Prospective cohort study. Participants: In total, 5402 people with a new diagnosis of head and neck cancer were recruited from 76 cancer centres in the United Kingdom between April 2011 and December 2014. Results: Initially, 161/5402 (3%) and 5241/5402 (97%) of participants were treated with ‘non-curative’ and ‘curative’ intent respectively. Within 12 months, 109/161 (68%) in the ‘non-curative’ group died compared with 482/5241 (9%) in the ‘curative’ group. Catastrophic bleed was the terminal event for 10.4% and 9.8% of people in ‘non-curative’ and ‘curative’ groups respectively; terminal airway obstruction was recorded for 7.5% and 6.3% of people in the same corresponding groups. Similar proportions of people in both groups died in a hospice (22.9% ‘non-curative’; 23.5% ‘curative’) and 45.7% of the ‘curative’ group died in hospital. Conclusions: In addition to those with incurable head and neck cancer, there is a small but significant ‘curative’ subgroup of people who may have palliative needs shortly following diagnosis. Given the high mortality, risk of acute catastrophic event and frequent hospital death, clarifying the level and timing of palliative care services engagement would help provide assurance as to whether palliative care needs are being met
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