Recurrent 15q13.3 microdeletions were recently identified with identical proximal (BP4) and distal (BP5) breakpoints and associated with mild to moderate mental retardation and epilepsy.
To assess ...further the clinical implications of this novel 15q13.3 microdeletion syndrome, 18 new probands with a deletion were molecularly and clinically characterised. In addition, we evaluated the characteristics of a family with a more proximal deletion between BP3 and BP4. Finally, four patients with a duplication in the BP3-BP4-BP5 region were included in this study to ascertain the clinical significance of duplications in this region.
The 15q13.3 microdeletion in our series was associated with a highly variable intra- and inter-familial phenotype. At least 11 of the 18 deletions identified were inherited. Moreover, 7 of 10 siblings from four different families also had this deletion: one had a mild developmental delay, four had only learning problems during childhood, but functioned well in daily life as adults, whereas the other two had no learning problems at all. In contrast to previous findings, seizures were not a common feature in our series (only 2 of 17 living probands). Three patients with deletions had cardiac defects and deletion of the KLF13 gene, located in the critical region, may contribute to these abnormalities. The limited data from the single family with the more proximal BP3-BP4 deletion suggest this deletion may have little clinical significance. Patients with duplications of the BP3-BP4-BP5 region did not share a recognisable phenotype, but psychiatric disease was noted in 2 of 4 patients.
Overall, our findings broaden the phenotypic spectrum associated with 15q13.3 deletions and suggest that, in some individuals, deletion of 15q13.3 is not sufficient to cause disease. The existence of microdeletion syndromes, associated with an unpredictable and variable phenotypic outcome, will pose the clinician with diagnostic difficulties and challenge the commonly used paradigm in the diagnostic setting that aberrations inherited from a phenotypically normal parent are usually without clinical consequences.
Borna disease virus (BDV) is a novel PNA virus that has only recently been characterised and classified in a new virus family, Bornaviridae. The virus was detected in buffy coat cells from four of ...five cats with neurological disease and in the brains of five of 15 cats with nervous signs and of one of three cats with non-neurological disease. In a serosurvey of 111 cats the incidence of antibody to BDV in cats with neurological disease was higher than in cats with other types of disease, suggesting that the virus may play a role in nervous diseases of cats in the UK.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Superconductivity in dense MgB2 wires Canfield, P C; Finnemore, D K; Bud'ko, S L ...
Physical review letters,
2001-Mar-12, 20010312, 2001-03-12, Volume:
86, Issue:
11
Journal Article
Peer reviewed
MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be ...prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.
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The upper critical field, H(c2), of Mg(B1-xCx)(2) has been measured in order to probe the maximum magnetic field range for superconductivity that can be attained by C doping. Carbon doped MgB2 ...filaments were prepared, and for carbon levels below 4% the transition temperatures are depressed by about 1 K/% C and H(c2)(T=0) rises by about 5 T/% C. This means that 3.8% C substitution will depress T(c) from 39.2 to 36.2 K and raise H(c2)(T=0) from 16.0 to 32.5 T. These rises in H(c2) are accompanied by a rise in resistivity at 40 K from about 0.5 to about 10 microOmega cm.
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The basic physical properties of MgB2 have been well established over the past two years of intensive research. At this point there is a general consensus about the values for the isotope shift, ...critical fields, most of the salient length scales, and general anisotropies. In this paper we will review the determination of these parameters and set the stage for further, more detailed discussions of specific aspects of the physics of MgB2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We have succeeded in increasing the upper critical field of polycrystalline MgB
2 wire segments to near 36
T by the substitution of 5.2% carbon for boron. We present fabrication details and physical ...properties of Mg(B
1−
x
C
x
)
2 for
x up to 0.052. Carbon doping was achieved using a two step reaction technique which involved an initial carbon doping of boron wire segments using chemical vapor deposition (CVD) followed by exposure of the carbon doped boron segments to magnesium vapor. The carbon content was determined by the relative contraction of the
a-lattice parameter. The superconducting transition temperature is suppressed by approximately 1
K/%C while
H
c
2
⊥
c
(
T
=
0
)
rises at a rate of nearly 4
T/%C.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Gas phase plasma synthesis methods have been used to prepare nano-scale particles of C doped boron powder that are well suited for powder-in-tube (PIT) fabrication of superconducting wire. Mixtures ...of H2, BCl3, and CH4 gas are injected into an induction plasma where doped boron powder is formed and collected on a stainless steel screen. The particles typically are ∼20nm in size and collect into lacy agglomerates in the 1–50μm size range. Pressed pellets of these powders heated in a Mg atmosphere are transformed to the MgB2 phase at temperatures ranging from 600°C to 1200°C. Critical current densities, Jc, at 5K run from about 106A/cm2 at self-field to 4×104A/cm2 at 7T. At 20K, Jc ranges from 5×105A/cm2 at self-field to about 104A/cm2 at 3T. Samples of pure B powder and B with 7.4%C powder were prepared as PIT wires having a combination Fe inner jacket and a cupro-nickel outer jacket. These PIT Jc values are lower than, but comparable to the pressed pellet values. The PIT samples can be reacted in times on the order of 10min and still exhibit greater than 105A/cm2 at 5K and 2T.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The view from the south is, more than ever, dominated by ominous signs of change. Antarctica and the Southern Ocean are intrinsic to the Earth system, and their evolution is intertwined with and ...influences the course of the Anthropocene. In turn, changes in the Antarctic affect and presage humanity's future. Growing understanding is countering popular beliefs that Antarctica is pristine, stable, isolated, and reliably frozen. An aspirational roadmap for Antarctic science has facilitated research since 2014. A renewed commitment to gathering further knowledge will quicken the pace of understanding of Earth systems and beyond. Progress is already evident, such as addressing uncertainties in the causes and pace of ice loss and global sea-level rise. However, much remains to be learned. As an iconic global “commons,” the rapidity of Antarctic change will provoke further political action. Antarctic research is more vital than ever to a sustainable future for this One Earth.
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Antarctica and the Southern Ocean are intrinsic to the Earth system, and their evolution is intertwined with, and influences, the course of the Anthropocene. In this review, Kennicutt et al. evaluate the progress made since the SCAR Horizon Scan charted the course for Antarctic science in 2014. They show that while much has been learned, open questions remain and that in the current climate of instability, Antarctic research is more vital than ever to a sustainable future for this one Earth.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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