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Lipid and Protein Transfer between Nanolipoprotein Particles and Supported Lipid Bilayers.
A nanolipoprotein particle (NLP) is a lipid bilayer disc stabilized by two amphipathic "scaffold" apolipoproteins. It has been most notably utilized as a tool for solubilizing a variety of membrane proteins while preserving structural and functional properties. Transfer of functional proteins from NLPs into model membrane systems such as supported lipid bilayers (SLBs) would enable new opportunities, for example, two-dimensional protein crystallization and studies on protein-protein interactions. This work used fluorescence microscopy and atomic force microscopy to investigate the interaction between NLPs and SLBs. When incubated with SLBs, NLPs were found to spontaneously deliver lipid and protein cargo. The impact of membrane composition on lipid exchange was explored, revealing a positive correlation between the magnitude of lipid transfer and concentration of defects in the target SLB. Incorporation of lipids capable of binding specifically to polyhistidine tags encoded into the apolipoproteins also boosted transfer of NLP cargo. Optimal conditions for lipid and protein delivery from NLPs to SLBs are proposed based on interaction mechanisms
Giving voice to equitable collaboration in participatory design
An AHRC funded research project titled Experimenting with the Co-experience Environment (June 2005 – June 2006) culminated in a physical environment designed in resonance with a small group of participants. The participants emerged from different disciplines coming together as a group to share their expertise and contribute their knowledge to design. They engaged in storytelling, individual and co-thinking, creating and co-creating, sharing ideas that did not require justification, proposed designs even though most were not designers …and played. The research questioned how a physical environment designed specifically for co-experiencing might contribute to new knowledge in design? Through play and by working in action together the participants demonstrated the potential of a physical co-experience environment to function as a scaffold for inter-disciplinary design thinking,saying, doing and making (Ivey & Sanders 2006). Ultimately the research questioned how this outcome might influence our approach to engaging participants in design research and experimentation
Virtual returns: Colonial postcards online and digital ‘nostalgérie’ among the former European settlers of Algeria
This article analyses how certain former European settlers of Algeria (pieds-noirs) have created a digital space of remembrance online using scans of colonial-era postcards. Tracing the role of colonial-era postcards in pied-noir memory narratives, from the phototexts of the 1980s to websites from the mid-2000s onwards, I suggest these digital sites of memory attempt to maintain a connection to an imagined Algerian homeland during the so-called ‘memory wars’. By collecting, scanning, and reproducing postcards and photographs of colonial landscapes, pieds-noirs websites aim to reconstruct a lost topography of houses, shops, streets, and towns that have been renamed and rebuilt since independence. These ‘virtual returns’ to Algerian urban topographies rely predominantly on affective responses to ‘nostalgérie’ or nostalgia for Algeria. However, in relying on colonial-era postcards they ultimately recreate the ‘visual economy’ (Welch and McGonagle) of French Algeria in the early 20th century. I argue that, despite the radical ‘connectivity’ presented by the internet, these websites remain primarily focused on creating a homogenous collective memory for an imagined audience of pieds-noirs online. Nonetheless, I conclude by suggesting that this online model of colonial nostalgia has permeated, in limited but influential ways, how other groups interpret visual ‘nostalgérie’
Brain neurons as quantum computers: {\it in vivo} support of background physics
The question: whether quantum coherent states can sustain decoherence,
heating and dissipation over time scales comparable to the dynamical timescales
of the brain neurons, is actively discussed in the last years. Positive answer
on this question is crucial, in particular, for consideration of brain neurons
as quantum computers. This discussion was mainly based on theoretical
arguments. In present paper nonlinear statistical properties of the Ventral
Tegmental Area (VTA) of genetically depressive limbic brain are studied {\it in
vivo} on the Flinders Sensitive Line of rats (FSL). VTA plays a key role in
generation of pleasure and in development of psychological drug addiction. We
found that the FSL VTA (dopaminergic) neuron signals exhibit multifractal
properties for interspike frequencies on the scales where healthy VTA
dopaminergic neurons exhibit bursting activity. For high moments the observed
multifractal (generalized dimensions) spectrum coincides with the generalized
dimensions spectrum calculated for a spectral measure of a {\it quantum} system
(so-called kicked Harper model, actively used as a model of quantum chaos).
This observation can be considered as a first experimental ({\it in vivo})
indication in the favour of the quantum (at least partially) nature of the
brain neurons activity
Impact of freight traffic on school walking decisions in urban environments
In light of the decline in social acceptance of walking and biking to school, there is a critical need to examine issues impacting school transportation decisions and to identify strategies to promote healthier behavior. In urban areas with high volume freight corridors, factors affecting school walking decisions can be complicated by increased truck and rail traffic. This paper presents findings from a study of urban neighborhoods in a major southeastern city, including those that are adjacent to freight corridors. Perceptions of neighborhood residents are compared in the context of existing infrastructure and network characteristics (urban vs. urban freight-centric). The results provide insight into factors influencing school transportation decisions in urban environments, and highlight discrepancies between perceptions and actual issues relevant to child pedestrian safety
Method for RNA extraction and transcriptomic analysis of single fungal spores
Transcriptomic analysis of single cells has been increasingly in demand in recent years, thanks to technological and methodological advances as well as growing recognition of the importance of individuals in biological systems. However, the majority of these studies have been performed in mammalian cells, due to their ease of lysis and high RNA content. No single cell transcriptomic analysis has yet been applied to microbial spores, even though it is known that heterogeneity at the phenotype level exists among individual spores. Transcriptomic analysis of single spores is challenging, in part due to the physically robust nature of the spore wall. This precludes the use of methods commonly used for mammalian cells. Here, we describe a simple method for extraction and amplification of transcripts from single fungal conidia (asexual spores), and its application in single-cell transcriptomics studies. The method can also be used for studies of small numbers of fungal conidia, which may be necessary in the case of limited sample availability, low-abundance transcripts or interest in small subpopulations of conidia.• The method allows detection of transcripts from single conidia of Aspergillus niger• The method allows detection of genomic DNA from single conidia of Aspergillus nige
NO PLIF Study of Hypersonic Transition Over a Discrete Hemispherical Roughness Element
Nitric oxide (NO) planar laser-induced fluorescence (PLIF) has been use to investigate the hypersonic flow over a flat plate with and without a 2-mm (0.08-in) radius hemispherical trip. In the absence of the trip, for all angles of attack and two different Reynolds numbers, the flow was observed to be laminar and mostly steady. Boundary layer thicknesses based on the observed PLIF intensity were measured and compared with a CFD computation, showing agreement. The PLIF boundary layer thickness remained constant while the NO flowrate was varied by a factor of 3, indicating non-perturbative seeding of NO. With the hemispherical trip in place, the flow was observed to be laminar but unsteady at the shallowest angle of attack and lowest Reynolds number and appeared vigorously turbulent at the steepest angle of attack and highest Reynolds number. Laminar corkscrew-shaped vortices oriented in the streamwise direction were frequently observed to transition the flow to more turbulent structures
Hamiltonian flows on null curves
The local motion of a null curve in Minkowski 3-space induces an evolution
equation for its Lorentz invariant curvature. Special motions are constructed
whose induced evolution equations are the members of the KdV hierarchy. The
null curves which move under the KdV flow without changing shape are proven to
be the trajectories of a certain particle model on null curves described by a
Lagrangian linear in the curvature. In addition, it is shown that the curvature
of a null curve which evolves by similarities can be computed in terms of the
solutions of the second Painlev\'e equation.Comment: 14 pages, v2: final version; minor changes in the expositio
Conservation laws for vacuum tetrad gravity
Ten conservation laws in useful polynomial form are derived from a Cartan
form and Exterior Differential System (EDS) for the tetrad equations of vacuum
relativity. The Noether construction of conservation laws for well posed EDS is
introduced first, and an illustration given, deriving 15 conservation laws of
the free field Maxwell Equations from symmetries of its EDS. The Maxwell EDS
and tetrad gravity EDS have parallel structures, with their numbers of
dependent variables, numbers of generating 2-forms and generating 3-forms, and
Cartan character tables all in the ratio of 1 to 4. They have 10 corresponding
symmetries with the same Lorentz algebra, and 10 corresponding conservation
laws.Comment: Final version with additional reference
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