10 research outputs found
Tafenoquine treatment of Plasmodium vivax malaria: suggestive evidence that CYP2D6 reduced metabolism is not associated with relapse in the Phase 2b DETECTIVE trial
Black hole spin: theory and observation
In the standard paradigm, astrophysical black holes can be described solely
by their mass and angular momentum - commonly referred to as `spin' - resulting
from the process of their birth and subsequent growth via accretion. Whilst the
mass has a standard Newtonian interpretation, the spin does not, with the
effect of non-zero spin leaving an indelible imprint on the space-time closest
to the black hole. As a consequence of relativistic frame-dragging, particle
orbits are affected both in terms of stability and precession, which impacts on
the emission characteristics of accreting black holes both stellar mass in
black hole binaries (BHBs) and supermassive in active galactic nuclei (AGN).
Over the last 30 years, techniques have been developed that take into account
these changes to estimate the spin which can then be used to understand the
birth and growth of black holes and potentially the powering of powerful jets.
In this chapter we provide a broad overview of both the theoretical effects of
spin, the means by which it can be estimated and the results of ongoing
campaigns.Comment: 55 pages, 5 figures. Published in: "Astrophysics of Black Holes -
From fundamental aspects to latest developments", Ed. Cosimo Bambi, Springer:
Astrophysics and Space Science Library. Additional corrections mad
Molecular and immunological analyses of confirmed Plasmodium vivax relapse episodes
International audienceBackground: Relapse infections resulting from the activation hypnozoites produced by Plasmodium vivax and Plasmodium ovale represent an important obstacle to the successful control of these species. A single licensed drug, primaquine is available to eliminate these liver dormant forms. To date, investigations of vivax relapse infections have been few in number.Results: Genotyping, based on polymorphic regions of two genes (Pvmsp1F3 and Pvcsp) and four microsatellite markers (MS3.27, MS3.502, MS6 and MS8), of 12 paired admission and relapse samples from P. vivax-infected patients were treated with primaquine, revealed that in eight of the parasite populations in the admission and relapse samples were homologous, and heterologous in the remaining four patients. The patients’ CYP2D6 genotypes did not suggest that any were poor metabolisers of primaquine. Parasitaemia tended to be higher in the heterologous as compared to the homologous relapse episodes as was the IgG3 response. For the twelve pro- and anti-inflammatory cytokine levels measured for all samples, only those of IL-6 and IL-10 tended to be higher in patients with heterologous as compared to homologous relapses in both admission and relapse episodes.Conclusions: The data from this limited number of patients with confirmed relapse episodes mirror previous observations of a significant proportion of heterologous parasites in relapses of P. vivax infections in Thailand. Failure of the primaquine treatment that the patients received is unlikely to be due to poor drug metabolism, and could indicate the presence of P. vivax populations in Thailand with poor susceptibility to 8-aminoquinolines
Transfer of marine mercury to mountain lakes
International audienceStocking is a worldwide activity on geographical and historical scales. The rate of non-native fish introductions have more than doubled over the last decades yet the effect on natural ecosystems, in the scope of biologically mediated transport and biomagnification of Hg and Hg-isotopes, is unknown. Using geochemistry (THg) and stable isotopes (N, Sr and Hg), we evaluate natal origin and trophic position of brown trout (Salmo trutta fario), as well as mercury biomagnification trends and potential pollution sources to three high-altitude lakes. Farmed trout show Hg-isotope signatures similar to marine biota whereas wild trout shows Hg-isotope signatures typical of fresh water lakes. Stocked trout initially show Hg-isotope signatures similar to marine biota. As the stocked trout age and shifts diet to a higher trophic level, THg concentrations increase and the marine Hg isotope signatures, induced via farm fish feed, shift to locally produced MeHg with lower δ 202 Hg and higher Δ 199 Hg. We conclude that stocking acts a humanly induced biovector that transfers marine Hg to freshwater ecosystems, which is seen in the Hg-isotopic signature up to five years after stocking events occurred. This points to the need of further investigations of the role of stocking in MeHg exposure to freshwater ecosystems
Defining the next generation of Plasmodium vivax diagnostic tests for control and elimination: Target product profiles
Origins and implications of neglect of G6PD deficiency and primaquine toxicity in Plasmodium vivax
Transient Black Hole Binaries
The last two decades have seen a great improvement in our understand- ing of
the complex phenomenology observed in transient black-hole binary systems,
especially thanks to the activity of the Rossi X-Ray Timing Explorer satellite,
com- plemented by observations from many other X-ray observatories and
ground-based radio, optical and infrared facilities. Accretion alone cannot
describe accurately the intricate behavior associated with black-hole
transients and it is now clear that the role played by different kinds of
(often massive) outflows seen at different phases of the outburst evolution of
these systems is as fundamental as the one played by the accretion process
itself. The spectral-timing states originally identified in the X-rays and
fundamentally based on the observed effect of accretion, have acquired new
importance as they now allow to describe within a coherent picture the
phenomenology observed at other wave- length, where the effects of ejection
processes are most evident. With a particular focus on the phenomenology seen
in the X-ray band, we review the current state-of-the-art of our knowledge of
black hole transients, describing the accretion-ejection connection at play
during outbursts through the evolution of the observed spectral-timing
properties. Although we mainly concentrate on the ob- servational aspects of
the global X-ray transient picture, we also provide physical insight to it by
reviewing (when available) the theoretical explanations and models proposed to
explain the observed phenomenology.Comment: 37 pages, 7 figures, to be published in: "Astrophysics of Black Holes
- From fundamental aspects to latest developments", Ed. Cosimo Bambi,
Springer: Astrophysics and Space Science Library. arXiv admin note: text
overlap with arXiv:0708.0148 by other author