1,032 research outputs found
The metagenomics of biosilicification: causes and effects
In order to determine the links between geochemical parameters controlling the formation of silica sinter in hot springs and their associated microbial diversity, a detailed characterisation of the waters and of in situ-grown silica sinters was combined with molecular phylogenetic analyses of the bacterial communities in Icelandic geothermal environments. At all but one site, the microorganisms clearly affected, and in part controlled, the formation of the macroscopic textures and structures of silica sinter edifices. In addition, the class and genera level phylogenetic diversity and distribution appeared to be closely linked to variations in temperature, salinity and pH regimes
The size and polydispersity of silica nanoparticles under simulated hot spring conditions
The nucleation and growth of silica nanoparticles in supersaturated geothermal waters was simulated using a flow-through geothermal simulator system. The effect of silica concentration ([SiO2]), ionic strength (IS), temperature (T) and organic additives on the size and polydispersity of the forming silica nanoparticles was quantified. A decrease in temperature (58 to 33°C) and the addition of glucose restricted particle growth to sizes <20 nm, while varying [SiO2] or ISdid not affect the size (30-35 nm) and polydispersity (±9 nm) observed at 58°C. Conversely, the addition of xanthan gum induced the development of thin films that enhanced silica aggregation
Anomalous pressure effect on the magnetic ordering in multiferroic BiMnO3
We report the magnetic field dependent dc magnetization and the
pressure-dependent (pmax ~ 16 kbar) ac susceptibilities Xp(T) on both powder
and bulk multiferroic BiMnO3 samples, synthesized in different batches under
high pressure. A clear ferromagnetic (FM) transition is observed at TC ~ 100 K,
and increases with magnetic field. The magnetic hysteresis behavior is similar
to that of a soft ferromagnet. Ac susceptibility data indicate that both the FM
peak and its temperature (TC) decrease simultaneously with increasing pressure.
Interestingly, above a certain pressure (9 ~ 11 kbar), another peak appears at
Tp ~ 93 K, which also decreases with increasing pressure, with both these peaks
persisting over some intermediate pressure range (9 ~ 13 kbar). The FM peak
disappears with further application of pressure; however, the second peak
survives until present pressure limit (pmax ~ 16 kbar). These features are
considered to originate from the complex interplay of the magnetic and orbital
structure of BiMnO3 being affected by pressure.Comment: 4 pages,4 figures, publised in Physical Review B 78, 092404/200
Gifted and talented education: The English policy highway at a crossroads?
Copyright © 2013 by Sage Publications. This is the author's accepted manuscript. The final published article is available from the link below.In 1999, the British government launched an education program for gifted and talented pupils as part of its Excellence in Cities initiative (EiC) that was initially designed to raise the educational achievement of very able pupils in state-maintained secondary schools in inner-city areas. Although some activities targeting gifted children had already been initiated by various voluntary organizations over several previous decades, this was the first time that the topic of improved provision for these pupils had been placed firmly within the national agenda. This article provides the background to the English gifted and talented policy “highway” and an overview of what was expected of schools. How practitioners responded to the policy, their beliefs and attitudes toward identifying gifted and talented pupils, and the opportunities and challenges that arose along the way to the current crossroads are explored. The need to empower teachers to feel more confident in classroom provisions for gifted and talented pupils is identified along with the potentially pivotal role of action research and “pupil voice” in the process of continued professional development and support
Parenting ‘gifted and talented’ children in urban areas: Parents' voices
This is the author's accepted manuscript. The final published article is available from the link below. Copyright © 2014 by SAGE Publications.International evidence demonstrates the importance of engaging parents in the education of their ‘high-potential’ children, yet limited research has focused on the involvement of parents from differing economic strata/backgrounds. The current study explored the dilemmas of parenting academically high-ability children from economically deprived urban areas in the UK. Data were gathered from a sample of parents whose children attended a university-based sustained intervention programme for designated ‘gifted’ pupils aged 12–16. Parental perceptions were sought in relation to (a) the usefulness/impact of the intervention programme, (b) parents’ aspirations for their children growing up in economically deprived urban areas and (c) parents’ views on the support provided by the extended family, peer groups and the wider community. The findings have significant implications for both policy and practice and, more specifically, for engaging parents in intervention programmes offered by universities and schools to children in order to increase their access to higher education and for enhancing their life chances
Colossal Electroresistance and Colossal Magnetoresistance in Spinel Multiferroic CdCr2S4
Colossal magnetoresistance (CMR) and electroresistance (CER) induced by the
electric field in spinel multiferroic CdCr2S4 are reported. It is found that a
metal-insulator transition (MIT) in CdCr2S4 is triggered by the electrical
field. In magnetic fields, the resistivity of CdCr2S4 responds similarly to
that of CMR manganites. Combing previous reports, these findings make CdCr2S4
the unique compound to possess all four properties of the colossal
magnetocapacitive (CMC), colossal electrocapacitive (CEC), CER, and CMR. The
present results open a new venue for searching new materials to show CMR by
tuning electric and magnetic fields.Comment: 3 pages, 4 figures, accepted by Applied Physics Letter
‘Can You Spot a Terrorist in Your Classroom?’ Problematising the Recruitment of Schools to the ‘War on Terror’ in the United Kingdom
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Complaints of rape and the criminal justice system: Fresh evidence on the attrition problem in England and Wales
The UK has one of the lowest conviction rates for rape in Europe. This article presents unique evidence on the factors that influence the attrition of rape allegations in the English criminal justice system. The study is based on a large, representative sample of rape allegations reported to the London Metropolitan Police, the UK’s biggest police force. The dataset contains unprecedented detail on the incident, victim, suspect and police investigation. The results lend support to the influence of some rape myths and stereotypes on attrition. These findings suggest that further central factors include the ethnicity of the suspect as well as what police officers and prosecutors perceive as evidence against the truthfulness of the allegation: the police record noting a previous false allegation by the victim, inconsistencies in the victim’s account of the alleged rape, and evidence or police opinion casting doubt on the allegation
Case management and Think First completion
“The final, definitive version of this article has been published in the Journal, Probation Journal, Vol 53 Issue 3, 2006, Copyright The Trade Union and Professional Association for Family Court and Probation Staff, by SAGE Publications Ltd at: http://prb.sagepub.com/ " DOI: 10.1177/0264550506066771This article considers the findings of a small-scale study of the practice of case managers supervising offenders required to attend the Think First Group. It explores the interface between one-to-one and group-based work within multi-modal programmes of supervision and seeks to identify those practices that support individuals in completing a group.Peer reviewe
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