CiteULike: Author Lashley

Formation of a New Dynamical Mode in alpha-Uranium Observed by Inelastic X-Ray and Neutron Scattering

ME Manley — 2008-05-05T16:32:03-00:00

Physical Review Letters, Vol. 96, No. 12. (2006)

Phonon dispersion curves were obtained from inelastic x-ray and neutron scattering measurements on -uranium single crystals at temperatures from 298 to 573 K. Both measurements showed a softening and an abrupt loss of intensity in the longitudinal optic branch along [00] above 450 K. Above the same temperature a new dynamical mode of comparable intensity emerges along the [01] zone boundary with energy near the top of the phonon spectrum. The new mode forms without a structural transition but coincides with an anomaly in the mechanical deformation behavior. We argue that the mode is an intrinsically localized vibration and formed as a result of a strong electron-phonon interaction.

A variant in CDKAL1 influences insulin response and risk of type 2 diabetes

Valgerdur Steinthorsdottir — 2007-05-30T12:46:40-00:00

Nature Genetics, Vol. 39, No. 6. (26 April 2007), pp. 770-775.

Pathological, clinical and genetic heterogeneity in progressive supranuclear palsy.

HR Morris — 2008-02-02T03:21:30-00:00

Brain, Vol. 125, No. Pt 5. (May 2002), pp. 969-975.

We have identified two groups of patients with clinically typical and atypical, pathologically diagnosed progressive supranuclear palsy (PSP), and investigated their genetic and molecular pathological characteristics. Those with clinically typical PSP are more likely to have the PSP susceptibility genotype and to have the deposition of PSP-type hyperphosphorylated tau protein. The clinically atypical PSP group contains a number of different clinical syndromes, including an L-dopa unresponsive bradykinetic syndrome and a clinical syndrome closely resembling idiopathic Parkinson's disease. The clinically atypical PSP group are less likely to have the PSP susceptibility genotype and often have the deposition of Alzheimer's disease paired helical filament type hyperphosphorylated tau. This study suggests that the tau PSP susceptibility genotype is most strongly associated with clinically typical PSP. Neurofibrillary tangle parkinsonian disorders, which pathologically resemble PSP but involve the deposition of Alzheimer's disease-type tau often without involvement of the tau susceptibility genotype, need to be distinguished for diagnostic and research purposes.

Electronic instabilities in shape-memory alloys: Thermodynamic and electronic structure studies of the martensitic transition

JC Lashley — 2008-01-16T10:45:13-00:00

Physical Review B (Condensed Matter and Materials Physics), Vol. 75, No. 20. (2007)

Using a variety of thermodynamic measurements made in magnetic fields, we show evidence that the diffusionless transition (DT) in many shape-memory alloys is related to significant changes in the electronic structure. We investigate three alloys that show the shape-memory effect (In-24 at. % Tl, AuZn, and U-26 at. % Nb). We observe that the DT is significantly altered in these alloys by the application of a magnetic field. Specifically, the DT in InTl-24 at. % shows a decrease in the DT temperature with increasing magnetic field. Further investigations of AuZn were performed using an ultrasonic pulse-echo technique in magnetic fields up to 45 T. Quantum oscillations in the speed of the longitudinal sound waves propagating in the [110] direction indicated a strong acoustic de Haas–van Alphen-type effect and give information about part of the Fermi surface.

A genome-wide search for linkage to renal function phenotypes in West Africans with type 2 diabetes.

G Chen — 2007-06-23T02:18:44-00:00

Am J Kidney Dis, Vol. 49, No. 3. (March 2007), pp. 394-400.

BACKGROUND: Reduced renal function often is a major consequence of diabetes and hypertension. Although several indices of renal function (eg, creatinine clearance) are clearly heritable and show linkage to several genomic regions, the specific underlying genetic determinants are still being sought. The purpose of this study is to conduct a genome-wide search for regions linked to 3 renal function phenotypes, serum creatinine, creatinine clearance, and glomerular filtration rate (GFR), in persons with type 2 diabetes. METHODS: A genome-wide panel of 372 autosomal short tandem repeat markers at an average spacing of 9 centimorgan were typed in 691 patients with type 2 diabetes (321 sib pairs and 36 half-sib pairs) in an affected sib pair study in West Africa. Linkage analysis was conducted with the 3 phenotypes by using a multipoint variance components linkage method. RESULTS: Creatinine clearance showed higher logarithm of odds (LOD) score than the other 2 phenotypes. Linkage to creatinine clearance was observed on chromosomes 16 (marker D16S539, LOD score of 3.56, empirical P = 0.0001), 17 (D17S1298, LOD score of 2.08, empirical P = 0.0018), and 7 (D7S1818, LOD score of 1.84, nominal P = 0.00181, empirical P = 0.0022). Maximum LOD scores for serum creatinine were observed on chromosomes 10 (D10S1432, LOD score of 2.53, empirical P = 0.0001) and 3 (D3S2418, LOD score of 2.21, empirical P = 0.0003) and for GFR on chromosomes 6 (D6S1040, LOD score of 2.08, empirical P = 0.0001) and 8 (D8S256, LOD score of 1.80, empirical P = 0.0001). Several of these results are replications of significant findings from other genome scans. CONCLUSION: A genome-wide scan for serum creatinine, creatinine clearance, and GFR in a West African sample showed linkage regions that may harbor genes influencing variation in these phenotypes. Potential candidate genes in these regions that have been implicated in diabetic nephropathy and/or renal damage in models of hypertension include CYBA (or P22PHOX) (16q24), NOX1 (10q22), and NOX3 (6q25.1-q26).

Clinical features of the DOK7 neuromuscular junction synaptopathy.

J Palace — 2007-06-25T12:37:00-00:00

Brain, Vol. 130, No. Pt 6. (June 2007), pp. 1507-1515.

Mutations in DOK7 have recently been shown to underlie a recessive congenital myasthenic syndrome (CMS) associated with small simplified neuromuscular junctions ('synaptopathy') but normal acetylcholine receptor and acetylcholinesterase function. We identified DOK7 mutations in 27 patients from 24 kinships. Mutation 1124_1127dupTGCC was common, present in 20 out of 24 kinships. All patients were found to have at least one allele with a frameshift mutation in DOK7 exon 7, suggesting that loss of function(s) associated with the C-terminal region of Dok-7 underlies this disorder. In 15 patients, we were able to study the clinical features in detail. Clinical onset was usually characterized by difficulty in walking developing after normal motor milestones. Proximal muscles were usually more affected than distal, leading to a 'limb-girdle' pattern of weakness; although ptosis was often present from an early age, eye movements were rarely involved. Patients did not show long-term benefit from anticholinesterase medication and sometimes worsened, and where tried responded to ephedrine. The phenotype can be distinguished from 'limb-girdle' myasthenia associated with tubular aggregates, where DOK7 mutations were not detected and patients respond to anticholinesterase treatments. CMS due to DOK7 mutations are common within our UK cohort and is likely to be under-diagnosed; recognition of the phenotype will help clinical diagnosis, targeted genetic screening and appropriate management.

In search of engram

KS Lashley — 2007-04-16T23:18:26-00:00

(1988), pp. 57-63.