298 research outputs found

    Effect of relative humidity on SOA formation from isoprene/NO photooxidation: enhancement of 2-methylglyceric acid and its corresponding oligoesters under dry conditions

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    The effect of relative humidity (RH) on secondary organic aerosol (SOA) formation from the photooxidation of isoprene under initially high nitric oxide (NO) conditions (i.e., isoprene/NO ~3) was investigated in a dual outdoor smog chamber. Based upon particle volume concentration measurements and the detailed chemical characterization of isoprene SOA using gas chromatography/mass spectrometry (GC/MS) and ultra performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS), enhanced SOA formation was observed under lower RH conditions (15-40 %) compared to higher RH conditions (40-90 %). 2-methylglyceric acid (2-MG) and its corresponding oligoesters, which have been previously shown to form from further oxidation of methacryloylperoxynitrate (MPAN), were enhanced in the particle-phase under lower RH conditions. In addition, an abundant unknown SOA tracer likely derived from the further oxidation of MPAN was detected and enhanced under lower RH conditions. In contrast, the 2-methyltetrols, which are known to mainly form from the reactive uptake of isoprene epoxydiols (IEPOX) under low-NO conditions in the presence of acidified aerosol, did not substantially vary under different RH conditions; however, isoprene-derived organosulfates were found to be enhanced under high-RH conditions, indicating the likely importance of the aqueous aerosol phase in their formation. Based upon the detailed chemical characterization results, particle-phase organic esterification is tentatively proposed to explain the observed enhancements of isoprene SOA mass under lower RH conditions. Alternative mechanisms explaining the enhancement of 2-MG and its corresponding oligoesters cannot be completely ruled out. This is one of only a few chamber studies that have examined the effect of RH on isoprene SOA formation. In comparison to our recent results obtained from aromatic SOA formation, the effect of RH on isoprene SOA formation is reversed. The results of this study highlight the importance of elucidating the key reactive intermediates that lead to SOA formation, especially since RH likely affects their ability in forming SOA. Furthermore, ignoring the effects of RH may significantly affect the accuracy of both regional and global SOA models

    Empowerment or Engagement? Digital Health Technologies for Mental Healthcare

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    We argue that while digital health technologies (e.g. artificial intelligence, smartphones, and virtual reality) present significant opportunities for improving the delivery of healthcare, key concepts that are used to evaluate and understand their impact can obscure significant ethical issues related to patient engagement and experience. Specifically, we focus on the concept of empowerment and ask whether it is adequate for addressing some significant ethical concerns that relate to digital health technologies for mental healthcare. We frame these concerns using five key ethical principles for AI ethics (i.e. autonomy, beneficence, non-maleficence, justice, and explicability), which have their roots in the bioethical literature, in order to critically evaluate the role that digital health technologies will have in the future of digital healthcare

    Performance over professional learning and the complexity puzzle: lesson observation in England’s further education sector

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    Attempts to measure the quality of teaching and learning have resulted in an overreliance on quantitative performance data and the normalisation of a set of reductionist practices in England’s further education sector in recent years. Focusing on lesson observation as an illustrative example and drawing on data from a national study, this article examines the application of observation and its impact on further education teachers’ practice. In viewing lesson observation through a complexity theory lens and contextualising it against the wider neoliberal backdrop of the marketisation of education, we seek to critique the inadequacies of current reductionist approaches to teacher evaluation, whilst simultaneously opening up a debate regarding the consequences of seeing classrooms as complex adaptive systems. In focusing on performative models of lesson observation in particular, the article exposes what we perceive as some of the epistemological and methodological shortcomings of neoliberalism in practice, but also offers an alternative way forward in dealing with the contested practice of evaluating the quality of teaching and learning

    Adeno-Associated Virus Technologies and Methods for Targeted Neuronal Manipulation

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    Cell-type-specific expression of molecular tools and sensors is critical to construct circuit diagrams and to investigate the activity and function of neurons within the nervous system. Strategies for targeted manipulation include combinations of classical genetic tools such as Cre/loxP and Flp/FRT, use of cis-regulatory elements, targeted knock-in transgenic mice, and gene delivery by AAV and other viral vectors. The combination of these complex technologies with the goal of precise neuronal targeting is a challenge in the lab. This report will discuss the theoretical and practical aspects of combining current technologies and establish best practices for achieving targeted manipulation of specific cell types. Novel applications and tools, as well as areas for development, will be envisioned and discussed

    The state of professional practice and policy in the English further education system: a view from below

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    This paper addresses a recurring theme regarding the UK’s Vocational Education and Training (VET) policy in which Further Education (FE) and training are primarily driven by employer demand. It explores the tensions associated with this process on the everyday working practices of FE practitioners and institutions and its impact on FE’s contribution to the wider processes of social and economic inclusion. At a time when Ofsted and employer-led organisations have cast doubt on the contribution of FE, we explore pedagogies of practice that are often unacknowledged by the current audit demands of officialdom. We argue that such practice provides a more enlightened view of the sector and the challenges it faces in addressing wider issues of social justice, employability and civic regeneration. At the same time, the irony of introducing laissez-faire initiatives designed to remove statutory qualifications for FE teachers ignores the progress made over the past decade in raising the professional profile and status of teachers and trainers in the sector. In addressing such issues, the paper explores the limits and possibilities of constructing professional and vocational knowledge from networks and communities of practice, schools, universities, business, employers and local authorities, in which FE already operates

    What should educational institutions be for?

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    In this article, I respond to the work of Gert Biesta regarding the question of what education should be for. He maintains education ought to be oriented towards the ‘good’ rather than measurement, accountability and efficiency. While sympathetic to such claims, I nonetheless question his avowal that discussion of the purposes of education needs to entail reflection upon tripartite processes of qualification, socialisation and subjectification. I also argue that the concept of subjectification presented by Biesta is elusive. He says educators cannot plan to produce it in students. He also suggests there is an unhelpful surplus of reason in education that constrains possibilities for subjectification. According to Biesta, education partly reproduces ‘rational communities’ that stifle the emergence of human uniqueness and inhibit persons from challenging accepted social orders. In response to this, I argue there is currently a deficit rather than a surplus of reason in education concerning the common good. Following MacIntyre, I claim that educational institutions should support students to learn how to think for themselves and act for the common good. I conclude that such utopian thinking about the purposes of education may be needed, now, more than ever

    Role of the IL-1 Pathway in Dopaminergic Neurodegeneration and Decreased Voluntary Movement

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    Interleukin-1 (IL-1), a proinflammatory cytokine synthesized and released by activated microglia, can cause dopaminergic neurodegeneration leading to Parkinsons disease (PD). However, it is uncertain whether IL-1 can act directly, or by exacerbating the harmful actions of other brain insults. To ascertain the role of the IL-1 pathway on dopaminergic neurodegeneration and motor skills during aging, we compared mice with impaired [caspase-1 knockout (casp1(-/-))] or overactivated IL-1 activity [IL-1 receptor antagonist knockout (IL-1ra(-/-))] to wild-type (wt) mice at young and middle age. Their motor skills were evaluated by the open-field and rotarod tests, and quantification of their dopamine neurons and activated microglia within the substantia nigra were performed by immunohistochemistry. IL-1ra(-/-) mice showed an age-related decline in motor skills, a reduced number of dopamine neurons, and an increase in activated microglia when compared to wt or casp1(-/-) mice. Casp1(-/-) mice had similar changes in motor skills and dopamine neurons, but fewer activated microglia cells than wt mice. Our results suggest that the overactivated IL-1 pathway occurring in IL-1ra(-/-) mice in the absence of inflammatory interventions (e.g., intracerebral injections performed in animal models of PD) increased activated microglia, decreased the number of dopaminergic neurons, and reduced their motor skills. Decreased IL-1 activity in casp1(-/-) mice did not yield clear protective effects when compared with wt mice. In summary, in the absence of overt brain insults, chronic activation of the IL-1 pathway may promote pathological aspects of PD per se, but its impairment does not appear to yield advantages over wt mice.Funding Agencies|John Curtin School of Medical Research, The Australian National University</p
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