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Ono, S.

Publications and source records attributed to Ono, S..

Dynamic electron correlations with charge order wavelength along all directions in the copper oxide plane

In strongly correlated systems the strength of Coulomb interactions between electrons, relative to their kinetic energy, plays a central role in determining their emergent quantum mechanical phases. We perform resonant x-ray scattering on Bi 2 Sr 2 CaCu 2 O 8+δ , a prototypical cuprate superconductor, to probe electronic correlations within the CuO 2 plane. We discover a dynamic quasi-circular pattern in the x-y scattering plane with a radius that matches the wave vector magnitude of the well-known static charge order. Along with doping- and temperature-dependent measurements, our experiments reveal a picture of charge order competing with superconductivity where short-range domains along x and y can dynamically rotate into any other in-plane direction. This quasi-circular spectrum, a hallmark of Brazovskii-type fluctuations, has immediate consequences to our understanding of rotational and translational symmetry breaking in the cuprates. We discuss how the combination of short- and long-range Coulomb interactions results in an effective non-monotonic potential that may determine the quasi-circular pattern.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

An Archean Biosphere Initiative

The search for life on extrasolar planets will necessarily focus on the imprints of biolgy on the composition of planetary atmospheres. The most notable biological imprint on the modern terrestrial atmosphere is the presence of 21 % O2, However, during most of the past 4 billion years, life and the surface environments on Earth were profoundly different than they are today. It is therefore a major goal of the astrobiology community to ascertain how the O2 content of the atmosphere has varied with time. and to understand the causes of these variations. The NAI and NASA Exobiology program have played critical roles in developing our current understanding of the ancient Earth's atmosphere, supporting diverse observational, analytical, and computational research in geoscience, life science, and related fields. In the present incarnation of the NAI, ongoing work is investigating (i) variations in atmospheric O2 in the Archean to the Cambrian, (ii) characterization of the redox state of the oceans shortly before, during and after the Great Oxidation Event (GOE), and (iii) unraveling the complex connections between environmental oxygenation, global climate, and the evolution of life.

Anbar, A. D.↗

Shallow Remineralization in the Sargasso Sea Estimated from Seasonal Variations in Oxygen and Dissolved Inorganic Carbon

A diagnostic model of the mean annual cycles of dissolved inorganic carbon (DIC) and oxygen below the mixed layer at the Bermuda Atlantic Time-series Study (BATS) site is presented and used to estimate organic carbon remineralization in the seasonal thermocline. The model includes lateral and vertical advection as well as vertical, diffusion. Very good agreement is found for the remineralization estimates based on oxygen and DIC. Net remineralization averaged from mid-spring to early fall is found to be a maximum between 120 and 140 in. Remineralization integrated between 100 (the compensation depth) and 250 m during this period is estimated to be about 1 mol C/sq m. This flux is consistent with independent estimates of the loss of particulate and dissolved organic carbon.

Ono, S.↗

Hyaluronic acid is increased in the skin and urine in patients with amyotrophic lateral sclerosis

We performed morphological studies of skin and measured glycosaminoglycans in the urine from patients with sporadic amyotrophic lateral sclerosis (ALS) and control subjects. The wide spaces separating collagen bundles reacted strongly with alcian blue stain in ALS patients and stained more markedly as ALS progressed. Staining with alcian blue was virtually eliminated by Streptomyces hyaluronidase. The urinary excretion of hyaluronic acid (HA) (mg/day) was significantly increased (P < 0.01) in ALS patients compared with that of control subjects, and there was a significant positive correlation between the excreted amount of HA and the duration of illness in advanced ALS patients with a duration of more than 2 years from clinical onset (r = 0.72, P < 0.02). We suggest that sporadic ALS includes a metabolic disorder of HA in which an accumulation of HA in the skin is linked to an increased urinary excretion of HA.

NASA Discipline Musculoskeletal↗

Amorphous material of the skin in amyotrophic lateral sclerosis: a morphologic and biochemical study

We performed morphologic studies on skin from seven patients with ALS and seven control subjects. By light microscopy, the wide spaces that separated collagen bundles reacted strongly with colloidal iron and alcian blue in ALS patients. Electron microscopy revealed markedly increased amorphous material that was positive for ruthenium red in the ground substance. These findings were not present in controls. Quantitative amino acid analysis showed that the amount of total amino acids (nmoles per mg dry weight) was significantly decreased (p < 0.01) in ALS patients compared with that of controls, and there was a significant negative correlation between skin amino acid content and duration of illness in ALS patients (r = -0.83, p < 0.001). These morphologic findings and biochemical data indicate that the amorphous material, which is markedly increased in ALS skin, includes glycosaminoglycans.

Non-NASA Center↗

Elastin cross-linking in the skin from patients with amyotrophic lateral sclerosis

Two cross-links unique to elastin, desmosine and isodesmosine were measured and compared in skin tissue (left upper arm) from 10 patients with amyotrophic lateral sclerosis (ALS) and from seven age-matched controls. The contents of desmosine and isodesmosine were significantly decreased (p < 0.01 and p < 0.01, respectively) in patients with ALS compared with those of controls, and were negatively and significantly associated with duration of illness in ALS patients (r = -0.77, p < 0.01 and r = -0.65, p < 0.05, respectively). The decline in skin desmosine and isodesmosine is more rapid in ALS than in normal ageing. Thus cross-linking of skin elastin is affected in ALS.

Non-NASA Center↗

Glutamate and aspartate are decreased in the skin in amyotrophic lateral sclerosis

We measured the levels of amino acids in biopsied skin from eight patients with amyotrophic lateral sclerosis (ALS) and seven controls. The most conspicuous changes in ALS patients were as follows. First, the contents of the acidic amino acids glutamate and aspartate were significantly decreased in ALS, and were negatively and significantly associated with the duration of illness. Second, the levels of the collagen-associated amino acids hydroxyproline, proline, glycine, alanine, and hydroxylysine were significantly decreased in ALS, and correlated inversely with the duration of illness. These results suggest that there are abnormalities of acidic amino acids and collagen-associated amino acids in the skin of patients with ALS. These changes may underlie the pathogenesis of ALS.

NASA Discipline Musculoskeletal↗

Amyotrophic lateral sclerosis: increased solubility of skin collagen

We studied the solubility of skin collagen from six patients with amyotrophic lateral sclerosis (ALS) and six controls. The amount of collagen extracted with neutral salt solution was significantly greater in patients with ALS than in controls. In addition, there was a statistically significant increase in the proportion of collagen extracted from ALS patients with increased duration of illness. The collagen solubilized by pepsin and cyanogen bromide treatments was significantly higher in ALS patients than in controls, and its proportion was positively and significantly associated with duration of illness in ALS patients. These results indicate that the metabolism of skin collagen may be affected in the disease process of ALS, causing an increase in immature soluble collagen in the tissue, which is the opposite to that which occurs in the normal aging process.

NASA Discipline Musculoskeletal↗

Collagen cross-linking of skin in patients with amyotrophic lateral sclerosis

Collagen cross-links of skin tissue (left upper arm) from 11 patients with amyotrophic lateral sclerosis (ALS) and 9 age-matched control subjects were quantified. It was found that patients with ALS had a significant reduction in the content of an age-related, stable cross-link, histidinohydroxylysinonorleucine, that was negatively correlated with the duration of illness. The contents of sodium borohydride-reducible labile cross-links, dehydro-hydroxylysinonorleucine and dehydro-histidinohydroxymerodesmosine, were significantly increased and were positively associated with the duration of illness (r = 0.703, p less than 0.05 and r = 0.684, p less than 0.05, respectively). The results clearly indicate that during the course of ALS, the cross-linking pathway of skin collagen runs counter to its normal aging, resulting in a "rejuvenation" phenomenon of skin collagen. Thus, cross-linking of skin collagen is affected in ALS.

Non-NASA Center↗