77 research outputs found
Salivary gland-specific <i>P. berghei</i> reporter lines enable rapid evaluation of tissue-specific sporozoite loads in mosquitoes
Malaria is a life-threatening human infectious disease transmitted by mosquitoes. Levels of the salivary gland sporozoites (sgs), the only mosquito stage infectious to a mammalian host, represent an important cumulative index of <i>Plasmodium</i> development within a mosquito. However, current techniques of sgs quantification are laborious and imprecise. Here, transgenic <i>P. berghei</i> reporter lines that produce the green fluorescent protein fused to luciferase (GFP-LUC) specifically in sgs were generated, verified and characterised. Fluorescence microscopy confirmed the sgs stage specificity of expression of the reporter gene. The luciferase activity of the reporter lines was then exploited to establish a simple and fast biochemical assay to evaluate sgs loads in whole mosquitoes. Using this assay we successfully identified differences in sgs loads in mosquitoes silenced for genes that display opposing effects on <i>P. berghei</i> ookinete/oocyst development. It offers a new powerful tool to study infectivity of <i>P. berghei</i> to the mosquito, including analysis of vector-parasite interactions and evaluation of transmission-blocking vaccines
Magnetic Phases of Electron-Doped Manganites
We study the anisotropic magnetic structures exhibited by electron-doped
manganites using a model which incorporates the double-exchange between orbital
ly degenerate electrons and the super-exchange between
electrons with realistic values of the Hund's coupling(), the
super-exchange coupling(), and the bandwidth(). We look at the
relative stabilities of the G, C and A type antiferromagnetic ph ases. In
particular we find that the G-phase is stable for low electron doping as seen
in experiments. We find good agreement with the experimentally observed
magnetic phase diagrams of electron-doped manganites
() such as NdSrMnO, PrSrMnO,
and SmCaMnO. We can also explain the experimentally
observed orbital structures of the C a nd A phases.
We also extend our calculation for electron-doped bilayer manganites of the
form RAMnO and predict that the C-phase will be
absent in t hese systems due to their reduced dimensionality.Comment: 7 .ps files included. To appear in Phys. Rev. B (Feb 2001
Phase Behavior of Type-II Superconductors with Quenched Point Pinning Disorder: A Phenomenological Proposal
A general phenomenology for phase behaviour in the mixed phase of type-II
superconductors with weak point pinning disorder is outlined. We propose that
the ``Bragg glass'' phase generically transforms via two separate thermodynamic
phase transitions into a disordered liquid on increasing the temperature. The
first transition is into a glassy phase, topologically disordered at the
largest length scales; current evidence suggests that it lacks the long-ranged
phase correlations expected of a ``vortex glass''. This phase has a significant
degree of short-ranged translational order, unlike the disordered liquid, but
no quasi-long range order, in contrast to the Bragg glass. This glassy phase,
which we call a ``multi-domain glass'', is confined to a narrow sliver at
intermediate fields, but broadens out both for much larger and much smaller
field values. The multi-domain glass may be a ``hexatic glass''; alternatively,
its glassy properties may originate in the replica symmetry breaking envisaged
in recent theories of the structural glass transition. Estimates for
translational correlation lengths in the multi-domain glass indicate that they
can be far larger than the interline spacing for weak disorder, suggesting a
plausible mechanism by which signals of a two-step transition can be obscured.
Calculations of the Bragg glass-multi-domain glass and the multi-domain
glass-disordered liquid phase boundaries are presented and compared to
experimental data. We argue that these proposals provide a unified picture of
the available experimental data on both high-T and low-T materials,
simulations and current theoretical understanding.Comment: 70 pages, 9 postscript figures, modified title and minor changes in
published versio
Physical volcanology and geochemistry of Palaeoarchaean komatiite lava flows from the western Dharwar craton, southern India: implications for Archaean mantle evolution and crustal growth
The polarized image of a synchrotron-emitting ring of gas orbiting a black hole
High Energy Astrophysic
Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
InstrumentationLarge scale structure and cosmolog
First sagittarius A* Event Horizon Telescope results. VI. Testing the black hole metric
Galaxie
A universal power-law prescription for variability from synthetic images of black hole accretion flows
Instrumentatio
Millimeter light curves of sagittarius A* observed during the 2017 Event Horizon Telescope campaign
Galaxie
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