227 research outputs found
Formation of Alkanes by Aerobic Carbon–Carbon Bond Coupling Reactions Catalyzed by a Phosphovanadomolybdic Acid
The valorization of alkanes is possible via carbon–carbon coupling reactions. A series of dialkyl cobalt complexes [(RCH_2)_2Co^(III)(bpy)_2]ClO_4 (R = H, Me, Et, and Ph) were reacted with the H_5PV_2Mo_(10)O_(40) polyoxometalate as a catalyst, leading to a selective oxidative carbon–carbon bond coupling reaction. The reaction is initiated by electron transfer from [(RCH_2)_2Co^(III)(bpy)_2]^+ to H_5PV^V_2Mo_(10)O_(40) to yield an intermediate [(RCH_2)_2Co^(IV)(bpy)_2]^(2+)–H_5PV^(IV)V^VMo_(10)O_(40), as identified by a combination of EPR and X-ray photoelectron spectroscopy experiments. The reaction is catalytic with O_2 as terminal oxidant representing an aerobic C–C bond coupling reaction
Spatial Modulation Microscopy for Real-Time Imaging of Plasmonic Nanoparticles and Cells
Spatial modulation microscopy is a technique originally developed for
quantitative spectroscopy of individual nano-objects. Here, a parallel
implementation of the spatial modulation microscopy technique is demonstrated
based on a line detector capable of demodulation at kHz frequencies. The
capabilities of the imaging system are shown using an array of plasmonic
nanoantennas and dendritic cells incubated with gold nanoparticles.Comment: 3 pages, 4 figure
Pertussis infection in fully vaccinated children in day-care centers, Israel.
We tested 46 fully vaccinated children in two day-care centers in Israel who were exposed to a fatal case of pertussis infection. Only two of five children who tested positive for Bordetella pertussis met the World Health Organization's case definition for pertussis. Vaccinated children may be asymptomatic reservoirs for infection
Ethics of Engagement and Insider-Outsider Perspectives: Issues and Dilemmas in Cross-Cultural Interpretation
This article offers insights into the ethics of engagement and methodological issues and dilemmas in cross-cultural interpretation for researchers who are positioned at different points of the insider-outsider spectrum. The discussion uses examples from qualitative research with Sikh families in Britain and focuses on the design of the methodology and co-interpretation of data from in-depth interviews, both during the interactive data gathering phase and the post-interview analysis and interpretation phase. The researchers represent differing degrees of insider-outsiderness in relation to the British Sikh community; one is a cultural insider (a Sikh) whilst the other is an outsider (non-Sikh). In other respects they share a number of characteristics, including gender, a history of migration, bilingualism and living and teaching in superdiverse communities which all impact on the nature of their engagement with the research participants and with each other as co-researchers. Our reflexive analysis shows that established binary distinctions and polarities in research practice, such as insider/outsider, are inadequate for conceptualising the fluidity and complexity of the ethics of engagement in co-researching. We argue that both theoretically and empirically a more nuanced conceptualisation reflects the realities of multiple researcher positionalities, interpretations and power relations
Rapid wide-field heterodyne interferometry with custom 2D CMOS camera
© The Institution of Engineering and Technology 2015. A wide-field pseudo-heterodyne interference contrast microscope is described, which employs a complementary metal-oxide semiconductor (CMOS) phase-sensitive camera. The use of multiple wells in the camera enables extremely rapid measurement of a full phase field at high resolution and the modulation frequency is not limited by the camera frame rate. The high data acquisition frequency allows the effects of microphonics to be frozen to mitigate the effect of lowfrequency disturbance
Collaborative action research through technologically mediated agoras.
ABSTRACT: The study presented in this article forms part of a wider project promoting collaboration between junior researchers from different universities with the objective of rethinking and improving teaching practice in relation to the use of technology. The article describes research carried out during the 2012/13 academic year aimed at developing collaborative action research through technologically mediated agoras involving students from three Spanish universities. The main results of this study show that junior researchers improved their teaching practice through technologically mediated inside and outside agoras. In addition, the transformation of university classrooms into agoras enabled the negotiated reconstruction of knowledge for the analysis of good practice in the use of technology. Likewise, these agoras helped reduce limitations by breaking down the barriers of time, distance and resources for sharing findings and limitations between junior researchers. Furthermore, they pave the way for improvements and their implementation in learning processes during initial teacher training
Cidades em (trans)formação: impacto da verticalização e densificação na qualidade do espaço residencial
Critical reflections on the benefits of ICT in education
In both schools and homes, information and communication technologies (ICT) are widely seen as enhancing learning, this hope fuelling their rapid diffusion and adoption throughout developed societies. But they are not yet so embedded in the social practices of everyday life as to be taken for granted, with schools proving slower to change their lesson plans than they were to fit computers in the classroom. This article examines two possible explanations - first, that convincing evidence of improved learning outcomes remains surprisingly elusive, and second, the unresolved debate over whether ICT should be conceived of as supporting delivery of a traditional or a radically different vision of pedagogy based on soft skills and new digital literacies. The difficulty in establishing traditional benefits, and the uncertainty over pursuing alternative benefits, raises fundamental questions over whether society really desires a transformed, technologically-mediated relation between teacher and learner
Ion energy distribution functions behind the sheaths of magnetized and non magnetized radio frequency discharges
The effect of a magnetic field on the characteristics of capacitively coupled
radio frequency discharges is investigated and found to be substantial. A
one-dimensional particle-in-cell simulation shows that geometrically symmetric
discharges can be asymmetrized by applying a spatially inhomogeneous magnetic
field. This effect is similar to the recently discovered electrical asymmetry
effect. Both effects act independently, they can work in the same direction or
compensate each other. Also the ion energy distribution functions at the
electrodes are strongly affected by the magnetic field, although only
indirectly. The field influences not the dynamics of the sheath itself but
rather its operating conditions, i.e., the ion flux through it and voltage drop
across it. To support this interpretation, the particle-in-cell results are
compared with the outcome of the recently proposed ensemble-in-spacetime
algorithm. Although that scheme resolves only the sheath and neglects
magnetization, it is able to reproduce the ion energy distribution functions
with very good accuracy, regardless of whether the discharge is magnetized or
not
Vilnius Declaration on chronic respiratory diseases : multisectoral care pathways embedding guided self-management, mHealth and air pollution in chronic respiratory diseases
Correction: Volume: 10 Issue: 1 Article Number: 49 DOI: 10.1186/s13601-020-00357-4 Published: DEC 17 2020Background: Over 1 billion people suffer from chronic respiratory diseases such as asthma, COPD, rhinitis and rhinosinusitis. They cause an enormous burden and are considered as major non-communicable diseases. Many patients are still uncontrolled and the cost of inaction is unacceptable. A meeting was held in Vilnius, Lithuania (March 23, 2018) under the patronage of the Ministry of Health and several scientific societies to propose multisectoral care pathways embedding guided self-management, mHealth and air pollution in selected chronic respiratory diseases (rhinitis, chronic rhinosinusitis, asthma and COPD). The meeting resulted in the Vilnius Declaration that was developed by the participants of the EU Summit on chronic respiratory diseases under the leadership of Euforea. Conclusion: The Vilnius Declaration represents an important step for the fight against air pollution in chronic respiratory diseases globally and has a clear strategic relevance with regard to the EU Health Strategy as it will bring added value to the existing public health knowledge.Peer reviewe
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