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Shewanella oneidensis MR-1 is a dissimilatory metal-reducing bacterium capable of reducing various metal and sulfur compounds and precipitating them in nanoparticulate form. Here, we report the synthesis of molybdenum disulfide nanomaterials at the site of S. oneidensis biofilms grown in the presence of molybdenum trioxide and sodium thiosulfate. Samples from the growth medium were imaged using scanning electron microscopy and characterized using transmission electron microscopy, energy-dispersive x-ray spectroscopy, absorbance spectroscopy, and x-ray diffraction. These methods revealed the presence of molybdenum disulfide nanoparticle aggregates 50-300 nm in diameter with both hexagonal and rhombohedral polytypes. As a biosynthesis method for molybdenum sulfide, the use of S. oneidensis offers the advantage of significantly reduced heat and chemical solvent input compared to conventional methods of synthesizing molybdenum disulfide nanoparticles.

As high-throughput genetic marker screening systems are essential for a range of genetics studies and plant breeding applications, the International RosBREED SNP Consortium (IRSC) has utilized the Illumina Infinium® II system to develop a medium- to high-throughput SNP screening tool for genome-wide evaluation of allelic variation in apple (Malus×domestica) breeding germplasm. For genome-wide SNP discovery, 27 apple cultivars were chosen to represent worldwide breeding germplasm and re-sequenced at low coverage with the Illumina Genome Analyzer II. Following alignment of these sequences to the whole genome sequence of 'Golden Delicious', SNPs were identified using SoapSNP. A total of 2,113,120 SNPs were detected, corresponding to one SNP to every 288 bp of the genome. The Illumina GoldenGate® assay was then used to validate a subset of 144 SNPs with a range of characteristics, using a set of 160 apple accessions. This validation assay enabled fine-tuning of the final subset of SNPs for the Illumina Infinium® II system. The set of stringent filtering criteria developed allowed choice of a set of SNPs that not only exhibited an even distribution across the apple genome and a range of minor allele frequencies to ensure utility across germplasm, but also were located in putative exonic regions to maximize genotyping success rate. A total of 7867 apple SNPs was established for the IRSC apple 8K SNP array v1, of which 5554 were polymorphic after evaluation in segregating families and a germplasm collection. This publicly available genomics resource will provide an unprecedented resolution of SNP haplotypes, which will enable marker-locus-trait association discovery, description of the genetic architecture of quantitative traits, investigation of genetic variation (neutral and functional), and genomic selection in apple.

Despite the functional importance of histidine (His) as an essential amino acid in proteins and as a metal-coordinating ligand, comparatively little is known about the regulation of its biosynthesis in plants and the potential for metabolic engineering of this pathway. To investigate the contribution of different steps in the pathway to overall control of His biosynthesis, nine His biosynthetic genes were individually over-expressed in Arabidopsis thaliana to determine their effects on free amino acid pools. Constitutive, CaMV 35S-driven over-expression of the cDNAs encoding either isoform of ATP-phosphoribosyltransferase (ATP-PRT), the first enzyme in the pathway, was sufficient to increase the pool of free His by up to 42-fold in shoot tissue of Arabidopsis, with negligible effect on any other amino acid. In contrast, over-expression of cDNAs for seven other enzymes in the biosynthetic pathway had no effect on His content, suggesting that control of the pool of free His resides largely with ATP-PRT activity. Over-expression of ATP-PRT and increased His content had a negative pleiotropic effect on plant biomass production in 35S:PRT1 lines, but this effect was not observed in 35S:PRT2 lines. In the presence of 100 microM Ni, which was inhibitory to wild-type plants, a strong positive correlation was observed between free His content and biomass production, indicating that the metabolic cost of His overproduction was outweighed by the benefit of increased tolerance to Ni. His-overproducing plants also displayed somewhat elevated tolerance to Co and Zn, but not to Cd or Cu, indicating chemical selectivity in intracellular metal binding by His.

Objective: Degenerative disorders of tendons present an enormous clinical challenge. They are extremely common, prone to recur and existing medical and surgical treatments are generally unsatisfactory. Recently eccentric, but not concentric, exercises have been shown to be highly effective in managing tendinopathy of the Achilles (and other) tendons. The mechanism for the efficacy of these exercises is unknown although it has been speculated that forces generated during eccentric loading are of a greater magnitude. Our objective was to determine the mechanism for the beneficial effect of eccentric exercise in Achilles tendinopathy., Methods: Seven healthy volunteers performed eccentric and concentric loading exercises for the Achilles tendon. Tendon force and length changes were determined using a combination of motion analysis, force plate data and real-time ultrasound., Results: There was no significant difference in peak tendon force or tendon length change when comparing eccentric with concentric exercises. However, high-frequency oscillations in tendon force occurred in all subjects during eccentric exercises but were rare in concentric exercises (P < 0.0001)., Conclusion: These oscillations provide a mechanism to explain the therapeutic benefit of eccentric loading in Achilles tendinopathy and parallels recent evidence from bone remodelling, where the frequency of the loading cycles is of more significance than the absolute magnitude of the force.

Objectives: Synovitis in rheumatoid arthritis (RA) is assessed clinically by the presence of joint tenderness and swelling. Synovial thickening and increased vascularity may also be detected by high-resolution ultrasonography (US) and power Doppler (PD). This study investigated the relationship between clinical and sonographic features of synovial disease utilizing US, PD and the contrast agent Sono-Vue., Methods: Forty RA patients were recruited. One proximal inter-phalangeal or metacarpophalangeal joint was selected per patient, as being unambiguously either: swollen and tender, just swollen, just tender or neither swollen nor tender (Nil). Ten joints were selected per clinical group. On US, the mean synovial thickness was measured and synovial hypertrophy and erosions were graded subjectively. Synovial vascularity demonstrated by PD was scored subjectively pre- and post-contrast., Results: All grades of synovial vascularity were found in each clinical group including the Nil group. There were significant differences between the four clinical groups for both synovial hypertrophy (P = 0.024) and PD scores pre- (P = 0.022) and post- (P = 0.039) contrast. Tender-only joints showed significantly less vascularity than other groups. Post-contrast, the median PD scores increased in all but the Nil group, in some cases from the normal to abnormal range., Conclusion: Synovitis demonstrated by US and PD is not predicted by patterns of disease as described by joint swelling and tenderness despite unambiguous selection of joints. Synovial vascularity was the least in tender-only joints and was heterogeneous in all other groups, including Nil joints. These findings question the reliability of traditional clinical signs in RA synovitis assessment.

Primary disorders of tendons are common and constitute a high proportion of referrals to rheumatologists. Certain tendons are particularly vulnerable to degenerative pathology; these include the Achilles, patella, elements of the rotator cuff, forearm extensors, biceps brachi and tibialis posterior tendons. Disorders of these tendons are often chronic and can be difficult to manage successfully in the long term. Significant advances have been made in understanding the pathophysiology of these conditions. Histopathological evidence, together with advances in imaging techniques, has made us more appreciative of the degenerative (rather that inflammatory) nature of these conditions. Additionally the presence of neovascularization is now well-recognized in long-standing tendinopathy. We review the mechanical, vascular and developing neural theories that attempt to explain the aetiology of degenerative tendinopathy. We also explore theories of why specific tendons (such as the Achilles and supraspinatus tendons) are particularly prone to degenerative pathology. Traditionally, treatments have placed a heavy emphasis on anti-inflammatory strategies, which are often inappropriate. Recently, however, significant advances in the practical management of tendon disorders have been made. In particular the advent of 'eccentric loading' training programmes has revolutionized the treatment of Achilles tendinopathy in some patients. This concept is currently being extended to include other commonly injured tendons. Other current treatments are reviewed, as are potential future treatments.

Background: The antiphospholipid (APS or Hughes') syndrome, anticardiolipin antibodies (aCL), and the lupus anticoagulant (LA) are associated with systemic lupus erythematosus, malignancy, infection, and drugs. It has been described in patients with primary systemic vasculitis (PSV)., Objective: To determine the prevalence of APS in patients with PSV attending a vasculitis clinic and the prevalence of patients with positive aCL and/or the LA who do not fulfil the classification criteria for APS., Methods: All case notes of patients attending the vasculitis clinic over a 12 month period were reviewed. Outpatients and inpatients were both included and were assessed for features of the APS and presence of aPL. Patients with positive aCL or LA tests were classified according to the significance of these results., Results: Of 144 patients with PSV, 25 had positive aCL or LA on at least one occasion, representing a point prevalence of 17%. Of these, nine had definite APS (classified by the Sapporo criteria) and a further four patients had clinical and serological features of APS, although insufficient to satisfy the Sapporo criteria. Twelve had only positive aPL., Conclusion: The antiphospholipid syndrome, aCL, and the LA may occur in association with PSV.

Plants that hyperaccumulate Ni exhibit an exceptional degree of Ni tolerance and the ability to translocate Ni in large amounts from root to shoot. In hyperaccumulator plants in the genus Alyssum, free His is an important Ni binding ligand that increases in the xylem proportionately to root Ni uptake. To determine the molecular basis of the His response and its contribution to Ni tolerance, transcripts representing seven of the eight enzymes involved in His biosynthesis were investigated in the hyperaccumulator species Alyssum lesbiacum by RNA gel blot analysis. None of the transcripts changed in abundance in either root or shoot tissue when plants were exposed to Ni, but transcript levels were constitutively higher in A. lesbiacum than in the congeneric nonaccumulator A. montanum, especially for the first enzyme in the biosynthetic pathway, ATP-phosphoribosyltransferase (ATP-PRT). Comparison with the weak hyperaccumulator A. serpyllifolium revealed a close correlation between Ni tolerance, root His concentration, and ATP-PRT transcript abundance. Overexpression of an A. lesbiacum ATP-PRT cDNA in transgenic Arabidopsis thaliana increased the pool of free His up to 15-fold in shoot tissue, without affecting the concentration of any other amino acid. His-overproducing lines also displayed elevated tolerance to Ni but did not exhibit increased Ni concentrations in either xylem sap or shoot tissue, suggesting that additional factors are necessary to recapitulate the complete hyperaccumulator phenotype. These results suggest that ATP-PRT expression plays a major role in regulating the pool of free His and contributes to the exceptional Ni tolerance of hyperaccumulator Alyssum species.

Some radiometric properties of gradient-index fiber lenses and lens arrays are explored. Consideration is restricted to the paraxial region of fibers that produce erect images at unit magnification. In two instances the radiometric properties of these lenses and lens arrays are considerably different from the properties of conventional (nongradient) lenses. First, the off-axis image plane irradiance for a single gradient-index fiber falls off far more rapidly than the familiar cos(4) law. Second, the exposure (integrated image irradiance) for a fiber array is independent of the object-to-image distance.

The best focus for a GRIN fiber array is shown to occur when the object and image plane vertex distances are equal, even when neither plane is the proper Gaussian unit magnification plane. This analytical result agrees with previous experimental data. With non-Gaussian imaging, the image plane of best focus for the GRIN array is not coincident with the plane of best focus for the individual gradient-index fibers.