The objective of this study was to examine the association between brain iron measurements of monoamine function and behavioural measurements of learning and memory. Male hybrid tilapias Oreochromis ...aureus × Oreochromis niloticus were fed either an iron‐deficient (ID) diet or an iron‐adequate (IA) diet for 8 weeks. The ID fishes showed significantly lower iron content in brain and decreasing learning and memory capacity. The fishes that showed increased learning and memory capacity had higher levels of iron and monoamine oxidase activity in brain. In addition, the results showed that learning and memory behaviours were related to monoamine (dopamine and noradrenaline) concentration in the brain. This suggests that iron can enhance learning and memory capacity in fishes and that the effect may have monoaminergic mediation in discrimination learning and memory tasks. The experimental data suggest that the properties and neural basis of learning and memory of teleosts are notably similar to those of land vertebrates.
The NOvA experiment has seen a 4.4σ signal of ν¯e appearance in a 2 GeV ν¯μ beam at a distance of 810 km. Using 12.33×1020 protons on target delivered to the Fermilab NuMI neutrino beamline, the ...experiment recorded 27 ν¯μ→ν¯e candidates with a background of 10.3 and 102 ν¯μ→ν¯μ candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm322|=2.48−0.06+0.11×10−3 eV2/c4 and sin2θ23 in the ranges from (0.53–0.60) and (0.45–0.48) in the normal neutrino mass hierarchy. The data exclude most values near δCP=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ23 values in the upper octant by 1.6σ.
Coherent X-Ray Diffraction Imaging Jianwei Miao; Sandberg, R. L.; Changyong Song
IEEE journal of selected topics in quantum electronics,
2012-Jan.-Feb., 2012-01-00, Letnik:
18, Številka:
1
Journal Article
Recenzirano
For centuries, lens-based microscopy, such as optical, phase-contrast, fluorescence, confocal, and electron microscopy, has played an important role in the evolution of modern science and technology. ...In 1999, a novel form of microscopy, i.e., coherent diffraction imaging (also termed coherent diffraction microscopy or lensless imaging), was developed and transformed our conventional view of microscopy, in which the diffraction pattern of a noncrystalline specimen or a nanocrystal was first measured and then directly phased to obtain a high-resolution image. The well-known phase problem was solved by combining the oversampling method with iterative algorithms. In this paper, we will briefly discuss the principle of coherent diffraction imaging, present various implementation schemes of this imaging modality, and illustrate its broad applications in materials science, nanoscience, and biology. As coherent X-ray sources such as high harmonic generation and X-ray free-electron lasers are presently under rapid development worldwide, coherent diffraction imaging can potentially be applied to perform high-resolution imaging of materials/nanoscience and biological specimens at the femtosecond time scale.
Heparanase is an endo-β-
d-glucuronidase involved in cleavage of heparan sulfate residues and hence participates in extracellular matrix degradation and remodeling. The heparanase cDNA encodes for a ...polypeptide of 543 amino acids that appears as a ∼65
kDa band in SDS–PAGE analysis. The protein undergoes a proteolytic cleavage that is likely to occur at two potential cleavage sites, Glu
109–Ser
110 and Gln
157–Lys
158, yielding an 8
kDa polypeptide at the N-terminus, a 50
kDa polypeptide at the C-terminus, and a 6
kDa linker polypeptide that resides in-between. The active form of heparanase has long been thought to be a 50
kDa polypeptide isolated from cells and tissues. However, attempts to obtain heparanase activity after expression of the 50
kDa polypeptide failed, suggesting that the N-terminal region is important for heparanase enzymatic activity. It has been hypothesized that heterodimer formation between the 8 and 50
kDa heparanase subunits is important for heparanase enzymatic activity. By individually or co-expressing the 8 and 50
kDa heparanase subunits in mammalian cells, we demonstrate specific association between the heparanase subunits by means of co-immunoprecipitation and pull-down experiments. Moreover, a region in the 50
kDa heparanase subunit that mediates interaction with the 8
kDa subunit was identified. Altogether, our results clearly indicate that heterodimer formation is necessary and sufficient for heparanase enzymatic activity in mammalian cells.
First-principles density functional calculations show that the high-pressure transitions of different semiconductors from zinc blende to rocksalt go through a transition state, which is universal in ...the sense that its position along the path and the corresponding geometry is independent of the chemical components of the semiconductor. This is explained using a Landau-like model expansion of the free energy in cosine functions of atomic position.
We present updated results from the NOvA experiment for νμ→νμ and νμ→νe oscillations from an exposure of 8.85×1020 protons on target, which represents an increase of 46% compared to our previous ...publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for νμ disappearance and νe appearance gives the best-fit point as normal mass hierarchy, Δm322=2.44×10−3 eV2/c4, sin2θ23=0.56, and δCP=1.21π. The 68.3% confidence intervals in the normal mass hierarchy are Δm322∈2.37,2.52×10−3 eV2/c4, sin2θ23∈0.43,0.51∪0.52,0.60, and δCP∈0,0.12π∪0.91π,2π. The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.
We report results from the first search for ν_{μ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we ...observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.
Summary
A family of nine Salmonella typhimurium type III secretion effectors with a conserved amino‐terminus have been defined. Three family members (SifA, SifB and SseJ) have previously been ...demonstrated to localize to the Salmonella‐containing vacuole and to Salmonella‐induced filaments. In contrast, we demonstrate that two other family members, SspH2 and SseI, co‐localized with the polymerizing actin cytoskeleton. These proteins also interacted with the mammalian actin cross‐linking protein filamin in the yeast two‐hybrid assay through their highly conserved amino‐terminal domains. This amino‐terminus was sufficient to direct localization to the polymerizing actin cytoskeleton, suggesting that the interaction with filamin is important for this subcellular localization. In addition, SspH2 co‐localized with vacuole‐associated actin polymerizations (VAP) induced by intracellular bacteria through the Salmonella pathogenicity island (SPI)‐2 type III secretion system (TTSS). SspH2 interacted with the actin‐binding protein profilin in the yeast two‐hybrid assay and by affinity chromatography. This interaction was highly specific to SspH2 and was mediated by its carboxy‐terminus. Furthermore, SspH2 inhibited the rate of actin polymerization in vitro, suggesting that it functions to reduce or remodel VAP. Strains with mutations in sspH2 and sseI retained the ability to form VAP. However, a third intracellular virulence factor, spvB, which ADP‐ribosylates actin, strongly inhibited VAP formation in HeLa cells, suggesting a more subtle effect for SspH2 and SseI on the actin cytoskeleton.
This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of $6.05\times10^{20}$ protons-on-target from the NuMI beam at the Fermi ...National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal mixing ($\theta_{23} = \pi/4$). Assuming the normal mass hierarchy, we find $\Delta m^2 = (2.67 \pm 0.11)\times 10^{-3}$ eV$^2$ and $\sin^2 \theta_{23}$ at the two statistically degenerate values $0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68% confidence level. Finally, our data disfavor the maximal mixing scenario with 2.6 $\sigma$ significance.
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