4,368 research outputs found
Case Report: Efavirenz as a cause of ataxia in children
Acute ataxia in childhood is often caused by toxin ingestion. With the increasing number of paediatric patients on antiretroviral medication, we observe more side-effects of these drugs. Acute ataxia is defined as unsteadiness of walking or fine motor movement of <72 hours. The most common causes are postinfectious acute cerebellar ataxia, toxin ingestion and Guillain-Barré syndrome. However, the possibility of a mass lesion must always be excluded. Reported neurological abnormalities in HIV-positive children range from 10% to 68%. A South African study found the prevalence of neurological complications to be 59%, the most common of which were HIV encephalopathy and long-tract motor signs; however, no cases of cerebellar dysfunction were documented. Ataxia rarely ocurs in an HIV-positive person, the chronic sequelae being neurocognitive impairment and polyneuropathy. Ataxia in the setting of HIV is generally secondary to an infectious, vascular or neoplastic cerebellar lesion. However, most infections are opportunistic and unlikely to occur when CD4 levels are adequate. The vascular or mass lesions are readily excluded with neuro-imaging. We report two cases of efavirenz toxicity that caused ataxia. We treated two children who presented in a 1-month period, which highlighted an important differential to consider in HIV-positive paediatric patients presenting with ataxia
Autosomal recessive myotonia congenita in sheep
International audienc
Astrometric effects of gravitational wave backgrounds with non-Einsteinian polarizations
The Gaia mission offers a new opportunity to search for the low-frequency gravitational wave background using astrometric measurements. In this paper, the astrometric effect of gravitational waves is reviewed, with a particular focus on the effect of non-Einsteinian gravitational wave polarizations. A stochastic gravitational wave background generates a correlated vector field of astrometric deflections on the sky. A convenient decomposition for the correlation matrix is introduced, enabling it to be calculated for all possible gravitational wave polarizations and compared to the redshift correlations from the pulsar-timing literature; in the case of a general relativity background of transverse traceless gravitational waves, this also allows us to identify an astrometric analog of the famous Hellings-Downs curve. Finally, the cross correlation between the redshift and astrometric signal is also calculated; this may form the basis for future joint pulsar-timing and astrometry searches for arbitrarily polarized gravitational wave backgrounds.D. M. is funded by the STFC. C. M. acknowledges financial support provided under the European Union’s H2020 ERC Consolidator Grant “Matter and strong-field gravity: New frontiers in Einsteins theory” grant agreement no. MaGRaTh646597. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 690904 and C. M. would like to acknowledge networking support by the COST Action CA16104
A live vaccine against Neospora caninum abortions in cattle
CommentaryMichael P. Reichel, Dadín P. Moore, Andrew Hemphill, Luis M. Ortega-Mora, J.P. Dubey, John T. Elli
A Candidate Sub-Parsec Supermassive Binary Black Hole System
We identify SDSS J153636.22+044127.0, a QSO discovered in the Sloan Digital
Sky Survey, as a promising candidate for a binary black hole system. This QSO
has two broad-line emission systems separated by 3500 km/sec. The redder system
at z=0.3889 also has a typical set of narrow forbidden lines. The bluer system
(z=0.3727) shows only broad Balmer lines and UV Fe II emission, making it
highly unusual in its lack of narrow lines. A third system, which includes only
unresolved absorption lines, is seen at a redshift, z=0.3878, intermediate
between the two emission-line systems. While the observational signatures of
binary nuclear black holes remain unclear, J1536+0441 is unique among all QSOs
known in having two broad-line regions, indicative of two separate black holes
presently accreting gas. The interpretation of this as a bound binary system of
two black holes having masses of 10^8.9 and 10^7.3 solar masses, yields a
separation of ~ 0.1 parsec and an orbital period of ~100 years. The separation
implies that the two black holes are orbiting within a single narrow-line
region, consistent with the characteristics of the spectrum. This object was
identified as an extreme outlier of a Karhunen-Loeve Transform of 17,500 z <
0.7 QSO spectra from the SDSS. The probability of the spectrum resulting from a
chance superposition of two QSOs with similar redshifts is estimated at
2X10^-7, leading to the expectation of 0.003 such objects in the sample
studied; however, even in this case, the spectrum of the lower redshift QSO
remains highly unusual.Comment: 8 pages, 2 figures, Nature in pres
High-quality draft genome sequence of the causal agent of the current Panama disease epidemic
This is the final version. Available from the American Society for Microbiology via the DOI in this record. We present a high-quality draft genome assembly for Fusarium oxysporum f. sp. cubense tropical race 4 (Fusarium odoratissimum), assembled from PacBio reads and consisting of 15 contigs with a total assembly size of 48.59 Mb. This strain appears to belong to vegetative compatibility group complex 01213/16.Medical Research CouncilWellcome TrustBBSR
Decreasing intensity of open-ocean convection in the Greenland and Iceland seas
The air–sea transfer of heat and fresh water plays a critical role in the global climate system. This is particularly true for the Greenland and Iceland seas, where these fluxes drive ocean convection that contributes to Denmark Strait overflow water, the densest component of the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). Here we show that the wintertime retreat of sea ice in the region, combined with different rates of warming for the atmosphere and sea surface of the Greenland and Iceland seas, has resulted in statistically significant reductions of approximately 20% in the magnitude of the winter air–sea heat fluxes since 1979. We also show that modes of climate variability other than the North Atlantic Oscillation (NAO) are required to fully characterize the regional air–sea interaction. Mixed-layer model simulations imply that further decreases in atmospheric forcing will exceed a threshold for the Greenland Sea whereby convection will become depth limited, reducing the ventilation of mid-depth waters in the Nordic seas. In the Iceland Sea, further reductions have the potential to decrease the supply of the densest overflow waters to the AMOC
Cutaneous metastases of breast carcinoma: a case report
© 2009 Vano-Galvan et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Re-structuring lentiviral vectors to express genomic RNA via cap-dependent translation
Lentiviral (LV) vectors based on human immunodeficiency virus type I (HIV-1) package two copies of their single-stranded RNA into vector particles. Normally, this RNA genome is reverse transcribed into a double-stranded DNA provirus that integrates into the cell genome, providing permanent gene transfer and long-term expression. Integration-deficient LV vectors have been developed to reduce the frequency of genomic integration and thereby limit their persistence in dividing cells. Here, we describe optimization of a reverse-transcriptase-deficient LV vector, which enables direct translation of LV RNA genomes upon cell entry, for transient expression of vector payloads as mRNA without a DNA intermediate. We have engineered a novel LV genome arrangement in which HIV-1 sequences are removed from the 5′ end, to enable ribosomal entry from the 5′ 7-methylguanylate cap for efficient translation of the vector payload. We have shown that this LV-mediated mRNA delivery platform provides transient transgene expression in vitro and in vivo. This has a potential application in gene and cell therapy scenarios requiring temporary payload expression in cells and tissues that can be targeted with pseudotyped LV vectors
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