269 research outputs found
Mental Maths: Just About What We Do In Our Heads?
No full textThis is an Accepted Manuscript of a book chapter published by Routledge/CRC Press in Debates in Mathematics Education on July 7, 2020, available online: https://www.routledge.com/Debates-in-Mathematics-Education/Ineson-Povey/p/book/978036707498
COMBINED USE OF OPEN-AIR AND INDOOR FUMIGATION SYSTEMS TO STUDY EFFECTS OF SO-2 ON LEACHING PROCESSES IN SCOTS PINE LITTER
No full textBoth an open-air fumigation system and a laboratory-based system were used to expose decomposing Scots pine (Pinus sylvestris L.) needles to controlled concentrations of SO2 (arithmetric mean less-than-or-equal-to 48 nl litre-1) during a period, in total, of 301 days. The experimental design involved reciprocal litter transplants from 'clean' to 'polluted' air and vice versa, using the two fumigation systems. The objectives were (1) to observe the effects of SO2 on leachate and litter chemistry, (2) to assess whether pollution-induced changes are reversible in clean air, and (3) to test the suitability of small-scale fumigation chambers (litter microcosms) compared with open-air systems in soil studies.Through the formation of SO4(2-) ions, dry-deposited SO2 exhibited a marked capacity to remove 'base' cations (Ca2+, Mg2+ and K+) from decomposing pine needles, and also to acidify litter leachates (as indicated by proton fluxes from the litter). When litter was transferred from polluted air (48 nl litre-1 SO2, in the open-air system) to either clean or polluted air in the laboratory, the effects of prior exposure to SO2 on leachate composition were still evident even after 86 days: the role of base cation depletion within the litter, caused by SO42- -induced leaching, is discussed.Data for SO42- fluxes in leachates collected from the small-scale chambers indicated that dry deposition velocities for SO2 were not anomalously high within this fumigation system. It is therefore concluded that microcosm studies can provide information complementary to the open-air fumigation approach in soils research.</p
Incidence, location and reasons for avoidable in-hospital cardiac arrest in a district general hospital
No full textAims: To determine the incidence of avoidable cardiac arrest among patients who had received resuscitation in a district general hospital. To establish how location and individual or system factors influence avoidable cardiac arrest in order to develop an evidence-based preventive strategy. Methods: Expert panel review of case-notes from 139 consecutive adult in-hospital cardiac arrests over 1 year. Results: There were 32348 adult admissions in 1999 with 1023 deaths. The cardiac arrest team was activated 139 times: 118 were for primary in-hospital cardiac arrest. The cardiac arrest rate excluding ‘do not attempt resuscitation’ (DNAR) cases was 3.8/1000 admissions. In 88.5% of deaths there was a DNAR policy. Survival to hospital discharge following resuscitation was 14%. Among the 118 cases, the panel unanimously agreed that 61.9% of arrests were potentially avoidable, rising to 68% when emergency department arrests were excluded (66 and 73% for majority opinion). Cardiac arrests were more likely at the weekend than during the week (P=0.02). The odds of potentially avoidable cardiac arrest was 5.1 times greater for patients in general wards than critical care areas (P<0.001); patients in critical care areas were more likely to survive (P<0.001). The odds of potentially avoidable cardiac arrest was 12.6 times greater for patients nursed in a clinical area judged ‘inappropriate’ for their main complaint (P<0.002, Fisher's exact test) compared to those nursed in ‘appropriate’ areas. The panel agreed that 100% of potentially avoidable arrests were judged to have received inadequate prior treatment. Clinical signs of deterioration in the preceding 24 h were not acted upon in 48%, and review was confined to a house officer in 45%. Conclusion: The majority of treated in-hospital cardiac arrests are potentially avoidable. Multiple system failures include delays and errors in diagnosis, inadequate interpretation of investigations, incomplete treatment, inexperienced doctors and management in inappropriate clinical areas.Objectivo: Determinar a incidência de paragens cardíacas evitáveis entre as vítimas de PCR que foram alvo de manobras de reanimação cardio-respiratória (RCR) num hospital distrital. Estabelecer a eventual relação entre o local da PCR e factores individuais e do sistema que possam relacionar-se com as PCR evitáveis, desenvolvendo desta forma uma estratégia preventiva com base na evidência. Métodos: Um painel de peritos reviu as notas de 139 PCR intra-hospitalares consecutivas em adultos durante um ano. Resultados: Houve 32348 admissões de adultos em 1999 com 1023 mortes. A equipa de paragem cardíaca foi activada 139 vezes: 118 por PCR intra-hospitalar primária. A taxa de paragem cardíaca excluindo os casos ‘do not attempt resuscitation’ (DNAR) foi de 3.8/1000 admissões. Em 88.5% das mortes existia uma política de DNAR. A sobrevivência à alta hospitalar após reanimação foi de 14%. Entre os 118 casos, os peritos do painel concordaram unanimemente que 61.9% das paragens eram potencialmente evitáveis, aumentando para 68% quando foram excluídas as paragens cardíacas no departamento de Emergência (66 e 73% por opinião da maioria). As paragens cardíacas eram mais prováveis ao fim de semana do que durante a semana (P=0.02). A taxa de paragem cardíaca potencialmente evitável foi 5.1 vezes superior para os pacientes em enfermarias gerais do que para os pacientes em áreas de cuidados críticos (P<0.001); os pacientes em áreas de cuidados críticos tinham maior probabilidade de sobreviver (P<0.001). A taxa de paragens cardíacas potencialmente evitáveis foi 12.6 vezes superior para vítimas a quem eram prestados cuidados em áreas clínicas julgadas como ‘inapropriadas’ para a sua queixa principal (P<0.002, teste exacto de Fisher) comparativamente com aqueles a quem foram prestados cuidados em áreas consideradas ‘apropriadas’. O painel de peritos concordou que em 100% das paragens potencialmente evitáveis o tratamento prévio foi inadequado. Sinais clínicos de deterioração nas 24 horas precedentes não foram detectados em 48% dos casos, e a revisão esteve confinada a um interno geral em 45%. Conclusão: A maioria das paragens cardíacas intra-hospitalares tratadas eram potencialmente evitáveis. Falências de multiplos sistemas incluiam atrasos e erros no diagnóstico, interpretação inadequada das investigações realizadas, tratamento incompleto, médicos inexperientes e abordagem em áreas clínicas inapropriadas.Resumen
Objetivos: Determinar la incidencia de paro cardíaco prevenible entre los pacientes que han recibido reanimación cardiopulmonar en un hospital general distrital. Establecer de que manera influyen en el paro cardíaco evitable, la localización y factores individuales o del sistema, para desarrollar una estrategia de prevención basada en evidencia. Métodos: Revisión, por un panel de expertos, de las notas de 139 paros cardíacos de adultos intrahospitalarios consecutivos ocurridos en un año. Resultados: hubo 32348 admisiones de adultos en 1999 con 1023 muertes. El equipo de paro cardíaco fue activado 139 veces: 118 de ellas por paro cardíaco primario intrahospitalario. La tasa de paro cardíaco, excluyendo los casos con ‘orden de no intentar reanimación’(DNAR) fue 3.8/1000 admisiones. En el 88.5% de las muertes había política de DNAR. La sobrevida al alta hospitalaria después de reanimación fue 14%. Entre los 118 casos, el panel acordó unánimemente que 61,9% de los paros eran potencialmente prevenibles, elevándose a 68% cuando se excluyen los paros de la unidad de emergencia (66 y 73% por opinión mayoritaria). Los paros eran mas probables durante los fines de semana que durante la semana (P=0.02). La probabilidad de paro cardíaco potencialmente evitable fue 5.1 veces mayor para pacientes en salas comunes que en áreas de cuidados críticos (P<0.001); los pacientes en áreas de cuidados críticos tenían mas probabilidades de sobrevivir (P<0.001).La probabilidad de paro cardíaco potencialmente evitable fue 12.6 veces mayor para pacientes cuidados en áreas clínicas juzgadas ‘inapropiadas’ para su problema principal (P<0.002, test exacto de Fisher) comparando aquellos cuidados en áreas juzgadas como ‘apropiadas’. El panel acordó que en el 100% de los paros cardíacos potencialmente evitables fueron juzgados como habiendo recibido tratamiento previo inadecuado. Los signos clínicos de deterioro en la 24 horas previas no recibieron acciones consecuentes en 48%, y la revisión fue confinada a un auxiliar en 45%. Conclusiones: La mayoría de los paros cardíacos intrahospitalarios tratados son potencialmente evitables. Las fallas en múltiples sistemas incluyen demora y errores en el diagnóstico, interpretación inadecuada de investigaciones, tratamiento incompleto, doctores inexpertos y manejo en áreas clínicas inadecuadas
Author Correction: El Niño–Southern Oscillation complexity (Nature, (2018), 559, 7715, (535-545), 10.1038/s41586-018-0252-6)
No full textIn this Review, the middle initial of author Kim M. Cobb was omitted. The original Review Article has been corrected online. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.11Nsciescopu
Digital game-based learning for formative assessment in mathematics education
No full textThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThis research explored how primary school teachers in England utilise digital game-based
learning (DGBL) in mathematics education and how formative assessment frameworks
such as Black and William’s (2009) five key strategies for effective formative assessment
and Burkhardt and Schoenfeld’s (2018, 2019) five dimensions of effective mathematics
lessons, can be applied to their DGBL approaches. Based on a pragmatist worldview, a
quasi-mixed method design consisting of quantitative surveys and qualitative interviews
was developed and conducted. 60 primary school teachers participated in the survey
whilst 10 teachers participated in the interviews. The quantitative data was scrutinised by
descriptive statistical analysis methods while reflexive thematic analysis was conducted
on the qualitative data. Findings revealed that primary school teachers in England consider
these digital games to be effective in increasing students’ motivation, enjoyment,
engagement, and academic achievement, however, they only utilise simple, practicebased
digital games that aim to increase students’ procedural fluency rather than higherorder
abilities such as conceptual understanding, strategic competence, or adaptive
reasoning. Furthermore, they strongly believe that both game characteristics and student
characteristics have a significant influence on digital educational games’ effectiveness in
primary school mathematics education. In terms of DGBL’s potential to be productively
used for formative assessment, it was found that how primary school teachers view and
utilise digital educational games in mathematics education does not satisfy either Black
and William’s (2009) all five key strategies for effective formative assessment or Burkhardt
and Schoenfeld’s (2018, 2019) all five dimensions of effective mathematics lessons.
Findings indicated that teachers do not find digital games suitable for, particularly,
clarifying and sharing learning intentions, engineering effective classroom discussions to
generate evidence of students’ understandings, providing effective feedback, and
providing equitable access to the maths learning environment. The study contributed to
existing knowledge by demonstrating the difference between teachers’ views on DGBL in
primary school mathematics education and what the literature has suggested so far,
highlighting DGBL’s potential to be used for formative assessment from the perspectives
of two different frameworks, suggesting a quasi-mixed method procedure rather than
conducting a short experiment, demonstrating a new approach to thematic analysis, and
informing the future decisions of educational executives. Finally, this study indicated the
necessity for further research comparing DGBL with non-digital game-based learning in
terms of efficacy, investigating the links between academic achievement in mathematics and concepts such as motivation, engagement, and enjoyment in a DGBL environment,
exploring DGBL’s efficacy when used as homework, inquiring into head teachers and local
educational authorities’ views on DGBL, and testing how DGBL helps low-achievers and
high-achievers differently more thoroughly.Ministry of Education of the Republic of Türkiy
Instrumental and relational understanding: What influences secondary student teachers’ teaching approaches?
No full textThis small-scale study of secondary maths PGCE student teachers used a range of calculation problems to explore their preferred method for solving problems for themselves, and for supporting pupils. Data gathered included written jottings of their calculations, identified strategies used in the classroom, and follow-up interviews to explore their approaches. Analysis used the I and S-Rationale framework (Herheim, 2023) to explore how they came to decisions about their proposed teaching approach in their classrooms. Results show that although they could identify a range of approaches to support long division and multiplication of decimals, a narrow procedural approach dominated responses to a division of fractions problem, both for themselves and for their teaching. Further time and space is needed to explore what might be possible for student teachers on a one-year postgraduate programme, to build their confidence and understanding, to encourage their pupils to have an S-Rationale approach to learning
Terrestrial organic carbon storage in a British moorland
No full textAccurate estimates for the size of terrestrial organic carbon (C) stores are needed to determine their importance in regulating atmospheric CO2 concentrations. The C stored in vegetation and soil components of a British moorland was evaluated in order to: (i) investigate the importance of these ecosystems for C storage and (ii) test the accuracy of the United Kingdom's terrestrial C inventory. The area of vegetation and soil types was determined using existing digitized maps and a Geographical Information System (GIS). The importance of evaluating C storage using 2D area projections, as opposed to true surface areas, was investigated and found to be largely insignificant. Vegetation C storage was estimated from published results of productivity studies at the site supplemented by field sampling to evaluate soil C storage. Vegetation was found to be much less important for C storage than soil, with peat soils, particularly Blanket bog, containing the greatest amounts of C. Whilst the total amount of C in vegetation was similar to the UK national C inventory's estimate for the same area, the national inventory estimate for soil C was over three times higher than the value derived in the current study. Because the UK's C inventory can be considered relatively accurate compared to many others, the results imply that current estimates for soil C storage, at national and global scales, should be treated with caution
The effects of acid nitrogen and acid sulphur deposition on CH4 oxidation in a forest soil: a laboratory study
No full textSieved soil and soil core experiments were performed to determine the potential sensitivity of forest soil CH4 oxidation to oxidised N, reduced N and oxidised S atmospheric deposition. Ammonium sulphate was used to simulate reduced N deposition, HNO3 oxidised N deposition and H2SO4 oxidised S deposition. The effects of NH4+, NO3-, SO42- and H+ on soil CH4 flux were shown to be governed by the associated counter-anion or cation of the investigated ions. Ammonium sulphate, at concentrations greater than those that would be experienced in polluted throughfall, showed a low potential to cause inhibition of CH4 oxidation. In contrast, HNO3 Strongly inhibited net CH4 oxidation in sieved soils and also in soil cores. In addition, soil CO2 production was inhibited and the organic and mineral soil horizons acidified in HNO3 treated soil cores. This suggested that the HNO3 effect on CH4 flux might be indirectly mediated through aluminium toxicity. Sulphuric acid only inhibited CH4 oxidation when added at pH 1. At concentrations more representative of heavily polluted throughfall, H2SO4 had no effect on soil CH4 flux or CO2 production from soil cores, even after 210 days of repeated addition. In contrast to HNO3 additions, acidification of the soil was not marked and was only significant for the mineral soil. The findings suggest that the response of forest soil CH4 oxidation to atmospheric acid deposition is strongly dependent on the form of acid deposition. (C) 2001 Elsevier Science Ltd. All rights reserved.</p
Exploring the "overflow tap" theory: linking forest soil CO2 fluxes and individual mycorrhizosphere components to photosynthesis
No full text"Quantifying soil organic carbon stocks (SOC) and their dynamics accurately is crucial for better predictions of climate change feedbacks within the atmosphere-vegetation soil system. However, the components, environmental responses and controls of the soil CO2 efflux (Rs) are still unclear and limited by field data availability. The objectives of this study were (1) to quantify the contribution of the various Rs components, specifically its mycorrhizal component, (2) to determine their temporal variability, and (3) to establish their environmental responses and dependence on gross primary productivity (GPP). In a temperate deciduous oak forest in south east England hourly soil and ecosystem CO2 fluxes over four years were measured using automated soil chambers and eddy covariance techniques. Mesh-bag and steel collar soil chamber treatments prevented root or both root and mycorrhizal hyphal in-growth, respectively, to allow separation of heterotrophic (Rh) and autotrophic (Ra) soil CO2 fluxes and the Ra components, roots (Rr) and mycorrhizal hyphae (Rm). Annual cumulative Rs values were very similar between years (740 ± 43 g C m-2 yr-1 ) with an average flux of 2.0 ± 0.3 µmol CO2 m-2 s-1 , but Rs components varied. On average, annual Rr , Rm and Rh fluxes contributed 38, 18 and 44 %, respectively, showing a large Ra contribution (56 %) with a considerable Rm component varying seasonally. Soil temperature largely explained the daily variation of Rs (R2 = 0.81), mostly because of strong responses by Rh (R2 = 0.65) and less so for Rr (R2 = 0.41) and Rm (R2 = 0.18). Time series analysis revealed strong daily periodicities for Rs and Rr , whilst Rm was dominated by seasonal (~150 days), and Rh by annual periodicities. Wavelet coherence analysis revealed that Rr and Rm were related to short-term (daily) GPP changes, but for Rm there was a strong relationship with GPP over much longer (weekly to monthly) periods and notably during periods of low Rr . The need to include individual Rs components in C flux models is discussed, in particular, the need to represent the linkage between GPP and Ra components, in addition to temperature responses for each component. The potential consequences of these findings for understanding the limitations for long-term forest C sequestration are highlighted, as GPP via root-derived C including Rm seems to function as a C “overflow tap”, with implications on the turnover of SOC.
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