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Imagining inclusive teachers: contesting policy assumptions in relation to the development of inclusive practice in schools
In this paper we reflect on data from two research projects in which inclusive practice in schools is at issue, in the light of wider field experience (our own and others’) of school and teacher development. We question what we understand to be relatively common, implicit policy assumptions about how teachers develop, by examining the way in which teachers are portrayed and located in these projects. The examples discussed in this paper draw on experience in Lao PDR and Bangladesh, critically exploring teachers’ roles, position and agency in practice. Similarities and differences rooted in cultural, political and institutional contexts highlight in a very productive way the significance and potential dangers of policy assumptions about teachers within the process of development.
In Bangladesh, a success story is presented: the case of a group of schools in which an institutional context for learning appears to sustain teachers’ commitment and motivation, with the effect of creating meaningful outcomes for young people who were previously outside the education system. These data raise questions about the significance of institutional context to teachers’ practices, and questions about approaches to teacher development which omit consideration of that context by, for example, focusing inadvertently on features of individual teachers.
We then consider teachers’ responses to the movement for inclusive education in a school in the Lao PDR since 2004. Inclusion here was understood to require a significant shift in teacher identity and a movement away from authoritative pedagogy towards the facilitation of a pedagogy which aimed to encourage the active participation of all students. Through a longitudinal study of teachers in one school, the conditions for such change were identified and again cast doubt on some of the assumptions behind large-scale attempts at teacher development. Reflecting on these experiences and the evidence they provide, we suggest that teacher development programmes are more likely to be effective where teachers are considered not as individuals subject to training but as agents located in an influential institutional context
A review of Laser Powder Bed Fusion Additive Manufacturing of aluminium alloys: Microstructure and properties
Additive manufacturing (AM) of metallic alloys for structural and functional applications has attracted significant interest in the last two decades as it brings a step change in the philosophy of design and manufacturing. The ability to design and fabricate complex geometries not amenable to conventional manufacturing, and the potential to reduce component weight without compromising performance, is particularly attractive for aerospace and automotive applications. This has culminated in rapid progress in AM with Ti- and Ni-based alloys. In contrast, the development of AM with Al-alloys has been slow, despite their widespread adoption in industry owing to an excellent combination of low density and high strength-to-weight ratio. Research to date has focused on castable and weldable AlSiMg-based alloys (which are less desirable for demanding structural applications), as well as on the development of new AM-specific AlMgSc alloys (based on 5xxx series). However, high strength wrought Al-alloys have typically been unsuitable for AM due to their unfavourable microstructural characteristics under rapid directional solidification conditions. Nevertheless, recent research has shown that there is promise in overcoming the associated challenges. Herein, we present a review of the current status of AM with Al-alloys. We primarily focus on the microstructural characteristics, and on exploring how these influence mechanical properties. The current metallurgical understanding of microstructure and defect formation in Al-alloys during AM is discussed, along with recent promising research exploring various microstructural modification methodologies. Finally, the remaining challenges in the development of AM with high-strength Al-alloys are discussed
An amplification-free ultra-sensitive electrochemical CRISPR/Cas biosensor for drug-resistant bacteria detection.
Continued development of high-performance and cost-effective diagnostic tools is vital for improving infectious disease treatment and transmission control. For nucleic acid diagnostics, moving beyond enzyme-mediated amplification assays will be critical in reducing the time and complexity of diagnostic technologies. Further, an emerging area of threat, in which diagnostics will play an increasingly important role, is antimicrobial resistance (AMR) in bacterial infections. Herein, we present an amplification-free electrochemical CRISPR/Cas biosensor utilizing silver metallization (termed E-Si-CRISPR) to detect methicillin-resistant (MRSA). Using a custom-designed guide RNA (gRNA) targeting the gene of MRSA, the Cas12a enzyme allows highly sensitive and specific detection when employed with silver metallization and square wave voltammetry (SWV). Our biosensor exhibits excellent analytical performance, with detection and quantitation limits of 3.5 and 10 fM, respectively, and linearity over five orders of magnitude (from 10 fM to 0.1 nM). Importantly, we observe no degradation in performance when moving from buffer to human serum samples, and achieve excellent selectivity for MRSA in human serum in the presence of other common bacteria. The E-Si-CRISPR method shows significant promise as an ultrasensitive field-deployable device for nucleic acid-based diagnostics, without requiring nucleic acid amplification. Finally, adjustment to a different disease target can be achieved by simple modification of the gRNA protospacer. [Abstract copyright: This journal is © The Royal Society of Chemistry.
Damping of Electron Density Structures and Implications for Interstellar Scintillation
The forms of electron density structures in kinetic Alfven wave turbulence
are studied in connection with scintillation. The focus is on small scales cm where the Kinetic Alfv\'en wave (KAW) regime is active in
the interstellar medium. MHD turbulence converts to a KAW cascade, starting at
10 times the ion gyroradius and continuing to smaller scales. These scales are
inferred to dominate scintillation in the theory of Boldyrev et al. From
numerical solutions of a decaying kinetic Alfv\'en wave turbulence model,
structure morphology reveals two types of localized structures, filaments and
sheets, and shows that they arise in different regimes of resistive and
diffusive damping. Minimal resistive damping yields localized current filaments
that form out of Gaussian-distributed initial conditions. When resistive
damping is large relative to diffusive damping, sheet-like structures form. In
the filamentary regime, each filament is associated with a non-localized
magnetic and density structure, circularly symmetric in cross section. Density
and magnetic fields have Gaussian statistics (as inferred from Gaussian-valued
kurtosis) while density gradients are strongly non-Gaussian, more so than
current. This enhancement of non-Gaussian statistics in a derivative field is
expected since gradient operations enhance small-scale fluctuations. The
enhancement of density gradient kurtosis over current kurtosis is not obvious,
yet it suggests that modest fluctuation levels in electron density may yield
large scintillation events during pulsar signal propagation in the interstellar
medium. In the sheet regime the same statistical observations hold, despite the
absence of localized filamentary structures. Probability density functions are
constructed from statistical ensembles in both regimes, showing clear formation
of long, highly non-Gaussian tails
Towards machines that understand people
The ability to estimate the state of a human partner is an insufficient basis on which to build cooperative agents. Also needed is an ability to predict how people adapt their behavior in response to an agent's actions. We propose a new approach based on computational rationality, which models humans based on the idea that predictions can be derived by calculating policies that are approximately optimal given human‐like bounds. Computational rationality brings together reinforcement learning and cognitive modeling in pursuit of this goal, facilitating machine understanding of humans
Transforming Nanomaterial Synthesis with Flow Chemistry
Microfluidic methods for the synthesis of nanomaterials allow the generation of high-quality products with outstanding structural, electronic and optical properties. At a fundamental level, this is engendered by the ability to control both heat and mass transfer in a rapid and precise manner, but also by the facile integration of in-line characterization tools and machine learning algorithms. Such integrated platforms provide for exquisite control over material properties during synthesis, accelerate the optimization of electronic and optical properties and bestow new insights into the optoelectronic properties of nanomaterials. Herein, we present a brief perspec-tive on the role that microfluidic technologies can play in nanomaterial synthesis, with a particular focus on recent studies that incorporate in-line optical characterization and machine learning. We also consider the importance and challenges associated with integrating additional functional components within experimental workflows and the upscaling of microfluidic platforms for production of industrial-scale quantities of nanomaterials
Kinetic Turbulence
The weak collisionality typical of turbulence in many diffuse astrophysical
plasmas invalidates an MHD description of the turbulent dynamics, motivating
the development of a more comprehensive theory of kinetic turbulence. In
particular, a kinetic approach is essential for the investigation of the
physical mechanisms responsible for the dissipation of astrophysical turbulence
and the resulting heating of the plasma. This chapter reviews the limitations
of MHD turbulence theory and explains how kinetic considerations may be
incorporated to obtain a kinetic theory for astrophysical plasma turbulence.
Key questions about the nature of kinetic turbulence that drive current
research efforts are identified. A comprehensive model of the kinetic turbulent
cascade is presented, with a detailed discussion of each component of the model
and a review of supporting and conflicting theoretical, numerical, and
observational evidence.Comment: 31 pages, 3 figures, 99 references, Chapter 6 in A. Lazarian et al.
(eds.), Magnetic Fields in Diffuse Media, Astrophysics and Space Science
Library 407, Springer-Verlag Berlin Heidelberg (2015
Farmer and veterinary practices and opinions related to fertility testing and pregnancy diagnosis of UK dairy cows
Environmental sustainability: A case of policy implementation failure?
© 2017 by the author. For a generation, governments around the world have been committed to sustainable development as a policy goal. This has been supported by an array of new policies ranging from international agreements, to national strategies, environmental laws at many levels of government, regional programs, and local plans. Despite these efforts, decades of scientific monitoring indicate that the world is no closer to environmental sustainability and in many respects the situation is getting worse. This paper argues that a significant contributing factor to this situation is policy implementation failure. A systematic review of the literature reveals that the failure to achieve the intended outcomes of environmental policies is due to economic, political and communication factors. Conflict between the objectives of environmental policies and those focused on economic development, a lack of incentives to implement environmental policies, and a failure to communicate objectives to key stakeholders are all key factors that contribute to the inability to attain environmental sustainability
Kinetics of CH₂OO reactions with SO₂, NO₂, NO, H₂O and CH₃CHO as a function of pressure
Kinetics of CH₂OO Criegee intermediate reactions with SO₂, NO₂, NO, H₂O and CH₃CHO and CH₂I radical reactions with NO₂ are reported as a function of pressure at 295 K. Measurements were made under pseudo-first-order conditions using flash photolysis of CH₂I₂–O₂–N₂ gas mixtures in the presence of excess co-reagent combined with monitoring of HCHO reaction products by laser-induced fluorescence (LIF) spectroscopy and, for the reaction with SO₂, direct detection of CH₂OO by photoionisation mass spectrometry (PIMS). Rate coefficients for CH₂OO + SO₂ and CH₂OO + NO₂ are independent of pressure in the ranges studied and are (3.42 ± 0.42) × 10‾¹¹ cm³ s‾¹ (measured between 1.5 and 450 Torr) and (1.5 ± 0.5) × 10‾¹² cm³ s‾¹ (measured between 25 and 300 Torr), respectively. The rate coefficient for CH₂OO + CH₃CHO is pressure dependent, with the yield of HCHO decreasing with increasing pressure. Upper limits of 2 × 10−13 cm³ s‾¹ and 9 × 10−17 cm³ s‾¹ are placed on the rate coefficients for CH₂OO + NO and CH₂OO + H₂O, respectively. The upper limit for the rate coefficient for CH₂OO + H₂O is significantly lower than has been reported previously, with consequences for modelling of atmospheric impacts of CH₂OO chemistry
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