2,154 research outputs found
Molecular cloning and functional expression of the human glycine transporter GlyT2 and chromosomal localisation of the gene in the human genome1The nucleotide sequence presented here has been submitted to the GenBank database under accession number AF085412.1
AbstractNeurotransmitter transport systems are major targets for therapeutic alterations in synaptic function. We have cloned and sequenced a cDNA encoding the human type 2 glycine transporter GlyT2 from human brain and spinal cord. An open reading frame of 2391 nucleotides encodes a 797 amino acid protein that transports glycine in a Na+/Clâ-dependent manner. When stably expressed in CHO cells, human GlyT2 displays a dose-dependent uptake of glycine with an apparent Km of 108 ÎŒM. This uptake is not affected by sarcosine at concentrations up to 1 mM. Radiation hybrid analysis mapped the GlyT2 gene to D11S1308 (LOD=8.988) on human chromosome 11p15.1â15.2
The Epitheliome: agent-based modelling of the social behaviour of cells
We have developed a new computational modelling paradigm for predicting the emergent behaviour
resulting from the interaction of cells in epithelial tissue. As proof-of-concept, an agent-based model,
in which there is a one-to-one correspondence between biological cells and software agents, has been
coupled to a simple physical model. Behaviour of the computational model is compared with the
growth characteristics of epithelial cells in monolayer culture, using growth media with low and
physiological calcium concentrations. Results show a qualitative fit between the growth characteristics
produced by the simulation and the in vitro cell models
Fractal Theory Space: Spacetime of Noninteger Dimensionality
We construct matter field theories in ``theory space'' that are fractal, and
invariant under geometrical renormalization group (RG) transformations. We
treat in detail complex scalars, and discuss issues related to fermions,
chirality, and Yang-Mills gauge fields. In the continuum limit these models
describe physics in a noninteger spatial dimension which appears above a RG
invariant ``compactification scale,'' M. The energy distribution of KK modes
above M is controlled by an exponent in a scaling relation of the vacuum energy
(Coleman-Weinberg potential), and corresponds to the dimensionality. For
truncated-s-simplex lattices with coordination number s the spacetime
dimensionality is 1+(3+2ln(s)/ln(s+2)). The computations in theory space
involve subtleties, owing to the 1+3 kinetic terms, yet the resulting
dimensionalites are equivalent to thermal spin systems. Physical implications
are discussed.Comment: 28 pages, 6 figures; Paper has been amplified with a more detailed
discussion of a number of technical issue
Assessment, evaluation and quality assurance: implications for integrity in reporting academic achievement in higher education
The terms assessment, evaluation and quality assurance have various interpretations in higher education. The first two, assessment and evaluation, share considerable conceptual ground and interconnected histories. Quality assurance, on the other hand, is a more recent development. The issue of academic achievement standards in particular has significant implications for quality assurance. The first half of this article provides a selective broad-brush outline of the topics just described. The second half is about an emerging concept, grade integrity, which is focused on the trustworthiness of course grades recorded on student academic transcripts. This focus serves as a platform to illustrate: how difficult issues can be analysed; why established conventions and assumptions need to be challenged; and how ways forward can be sought out and thought through. The context for the paper is higher education but the principles also apply to other educational sectors
Manganese(III) and its hydroxo- and chloro-complexes in aqueous perchloric acid: comparison with similar transition-metal(III) complexes
At 25°C the formation constant of MnCl2+ is found by spectrophotometry to be 13.2 ± 0.9 dm3 molâ1 at ionic strength 3.26 mol dmâ3; for MnCl+2 the value is 1.1 ± 0.7 dm3 molâ1. Increase in the number of chloride ions in complexes results in longer wavelengths for the corresponding absorption maxima. In the absence of chloride the hydrolysis constant of MnIII at ionic strength 5.6 mol dmâ3 is found from voltammetry and potentiometry to be 1.05± 0.26 mol dmâ3. Aged managanese(III) is found to be 15â25% polymeric, from both kinetic and e.m.f. measurements. Comparison of formation constants for halogeno- and hydroxo-complexes of M3+(first transition series) shows that a combination of charge-transfer, ligand-field and coulomb interactions underlies the observed sequences; the dipole moment of OHâ is also a factor
Primordial Black Holes: Observational Characteristics of The Final Evaporation
Many early universe theories predict the creation of Primordial Black Holes
(PBHs). PBHs could have masses ranging from the Planck mass to 10^5 solar
masses or higher depending on the size of the universe at formation. A Black
Hole (BH) has a Hawking temperature which is inversely proportional to its
mass. Hence a sufficiently small BH will quasi-thermally radiate particles at
an ever-increasing rate as emission lowers its mass and raises its temperature.
The final moments of this evaporation phase should be explosive and its
description is dependent on the particle physics model. In this work we
investigate the final few seconds of BH evaporation, using the Standard Model
and incorporating the most recent Large Hadron Collider (LHC) results, and
provide a new parameterization for the instantaneous emission spectrum. We
calculate for the first time energy-dependent PBH burst light curves in the
GeV/TeV energy range. Moreover, we explore PBH burst search methods and
potential observational PBH burst signatures. We have found a unique signature
in the PBH burst light curves that may be detectable by GeV/TeV gamma-ray
observatories such as the High Altitude Water Cerenkov (HAWC) observatory. The
implications of beyond the Standard Model theories on the PBH burst
observational characteristics are also discussed, including potential
sensitivity of the instantaneous photon detection rate to a squark threshold in
the 5 -10 TeV range.Comment: Accepted to Astroparticle Physics Journal (71 Pages, 22 Figures
The flip flop nozzle extended to supersonic flows
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76293/1/AIAA-1992-2724-750.pd
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Long-term changes to the frequency of occurrence of British moths are consistent with opposing and synergistic effects of climate and land-use changes
1. Speciesâ distributions are likely to be affected by a combination of environmental drivers. We used a data set of 11 million species occurrence records over the period 1970â2010 to assess changes in the frequency of occurrence of 673 macro-moth species in Great Britain. Groups of species with different predicted sensitivities showed divergent trends, which we interpret in the context of land-use and climatic changes.
2. A diversity of responses was revealed: 260 moth species declined significantly, whereas 160 increased significantly. Overall, frequencies of occurrence declined, mirroring trends in less species-rich, yet more intensively studied taxa.
3. Geographically widespread species, which were predicted to be more sensitive to land use than to climate change, declined significantly in southern Britain, where the cover of urban and arable land has increased.
4. Moths associated with low nitrogen and open environments (based on their larval host plant characteristics) declined most strongly, which is also consistent with a land-use change explanation.
5. Some moths that reach their northern (leading edge) range limit in southern Britain increased, whereas species restricted to northern Britain (trailing edge) declined significantly, consistent with a climate change explanation.
6. Not all species of a given type behaved similarly, suggesting that complex interactions between speciesâ attributes and different combinations of environmental drivers determine frequency of occurrence changes.
7. Synthesis and applications. Our findings are consistent with large-scale responses to climatic and land-use changes, with some species increasing and others decreasing. We suggest that land-use change (e.g. habitat loss, nitrogen deposition) and climate change are both major drivers of moth biodiversity change, acting independently and in combination. Importantly, the diverse responses revealed in this species-rich taxon show that multifaceted conservation strategies are needed to minimize negative biodiversity impacts of multiple environmental changes. We suggest that habitat protection, management and ecological restoration can mitigate combined impacts of land-use change and climate change by providing environments that are suitable for existing populations and also enable species to shift their ranges
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