1,669 research outputs found
Asperisporium and Pantospora (Mycosphaerellaceae): epitypifications and phylogenetic placement
The species-rich family Mycosphaerellaceae contains considerable morphological diversity and includes numerous anamorphic genera, many of which are economically important plant pathogens. Recent revisions and phylogenetic research have resulted in taxonomic instability. Ameliorating this problem requires phylogenetic placement of type species of key genera. We present an examination of the type species of the anamorphic Asperisporium and Pantospora. Cultures isolated from recent port interceptions were studied and described, and morphological studies were made of historical and new herbarium specimens. DNA sequence data from the ITS region and nLSU were generated from these type species, analysed phylogenetically, placed into an evolutionary context within Mycosphaerellaceae, and compared to existing phylogenies. Epitype specimens associated with living cultures and DNA sequence data are designated herein. Asperisporium caricae, the type of Asperisporium and cause of a leaf and fruit spot disease of papaya, is closely related to several species of Passalora including P. brachycarpa. The status of Asperisporium as a potential generic synonym of Passalora remains unclear. The monotypic genus Pantospora, typified by the synnematous Pantospora guazumae, is not included in Pseudocercospora sensu stricto or sensu lato. Rather, it represents a distinct lineage in the Mycosphaerellaceae in an unresolved position near Mycosphaerella microsora
High fat diet attenuates the anticontractile activity of aortic PVAT via a mechanism involving AMPK and reduced adiponectin secretion
Background and aim: Perivascular adipose tissue (PVAT) positively regulates vascular function through production of factors such as adiponectin but this effect is attenuated in obesity. The enzyme AMP-activated protein kinase (AMPK) is present in PVAT and is implicated in mediating the vascular effects of adiponectin. In this study, we investigated the effect of an obesogenic high fat diet (HFD) on aortic PVAT and whether any changes involved AMPK.
Methods: Wild type Sv129 (WT) and AMPKα1 knockout (KO) mice aged 8 weeks were fed normal diet (ND) or HFD (42% kcal fat) for 12 weeks. Adiponectin production by PVAT was assessed by ELISA and AMPK expression studied using immunoblotting. Macrophages in PVAT were identified using immunohistochemistry and markers of M1 and M2 macrophage subtypes evaluated using real time-qPCR. Vascular responses were measured in endothelium-denuded aortic rings with or without attached PVAT. Carotid wire injury was performed and PVAT inflammation studied 7 days later.
Key results: Aortic PVAT from KO and WT mice was morphologically indistinct but KO PVAT had more infiltrating macrophages. HFD caused an increased infiltration of macrophages in WT mice with increased expression of the M1 macrophage markers Nos2 and Il1b and the M2 marker Chil3. In WT mice, HFD reduced the anticontractile effect of PVAT as well as reducing adiponectin secretion and AMPK phosphorylation. PVAT from KO mice on ND had significantly reduced adiponectin secretion and no anticontractile effect and feeding HFD did not alter this. Wire injury induced macrophage infiltration of PVAT but did not cause further infiltration in KO mice.
Conclusions: High-fat diet causes an inflammatory infiltrate, reduced AMPK phosphorylation and attenuates the anticontractile effect of murine aortic PVAT. Mice lacking AMPKα1 phenocopy many of the changes in wild-type aortic PVAT after HFD, suggesting that AMPK may protect the vessel against deleterious changes in response to HFD
Brain rhythms define distinct interaction networks with differential dependence on anatomy
Cognitive functions are subserved by rhythmic neuronal synchronization across widely distributed brain areas. In 105 area pairs, we investigated functional connectivity (FC) through coherence, power correlation, and Granger causality (GC) in the theta, beta, high-beta, and gamma rhythms. Between rhythms, spatial FC patterns were largely independent. Thus, the rhythms defined distinct interaction networks. Importantly, networks of coherence and GC were not explained by the spatial distributions of the strengths of the rhythms. Those networks, particularly the GC networks, contained clear modules, with typically one dominant rhythm per module. To understand how this distinctiveness and modularity arises on a common anatomical backbone, we correlated, across 91 area pairs, the metrics of functional interaction with those of anatomical projection strength. Anatomy was primarily related to coherence and GC, with the largest effect sizes for GC. The correlation differed markedly between rhythms, being less pronounced for the beta and strongest for the gamma rhythm
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Large superconducting dipole magnet for the heavy ion spectrometer system (HISS)
The magnet is the central element of the spectrometer system, where it will be used to momentum-analyze secondary heavy-ion fragments at relativistic energies. High bending power and large acceptance apertures are necessary for simultaneous multiple fragment measurements. Free access over large angles to the magnetic volume is necessary to accommodate a variety of experiments and particle detection systems. The magnet has pole tips two meters in diameter, a one meter gap, and a maximum central field of three tesla. The coils are designed to be cryostable, with a helical winding pattern. A window-frame steel yoke limits the stray field and augments the cental field. In terms of its magnetic energy of 55 MJ it will be one of the twelve or so largest magnets in the world. Unusual engineering features of the magnet are the large magnetic forces (one million kg) between the coils at liquid helium temperature and the yoke at room temperature, and the large diameter (7 m) hydraulic cylinder base to provide rotation for the magnet. The magnet will be installed at the BEVALAC heavy-ion facility at Lawrence Berkeley Laboratory
Individual differences in cognitive reappraisal use and emotion regulatory brain function in combat‐exposed veterans with and without PTSD
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135971/1/da22551.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135971/2/da22551_am.pd
Changes in IP3 receptor expression and function in aortic smooth muscle of atherosclerotic mice
Peroxynitrite is an endothelium - independent vasodilator which induces relaxation via membrane hyperpolarisation. A ctivation of IP3 receptors triggers opening of potassium channels and hyperpolarisation. Previously we found that relaxation to peroxynitrite was maintained during development of atherosclerosis due to changes in expression of calcium regulatory proteins. In this study we investigated 1) the mechanism of peroxynitrite - induced relaxation in mouse aorta 2) the effect of atherosclerosis on relaxation to peroxynitrite and other vasodilators 3) the effect of atherosclerosis on expression and function of the IP3 receptor. Aortic function was studied using wire myography and atherosclerosis was induced by fat - feeding ApoE - / - mice . Expression of IP3 receptors was studied using Western blotting and immunohistochemistry . Relaxation to peroxynitrite was attenuated by the IP3 antagonists 2 - APB and xestospongin C and also the Kv channel blocker 4 - AP. Atherosclerosis attenuated vasodilation to cromakalim and the AMPK activator A769662 but not peroxynitrite. Relaxation was attenuated to a greater extent by 2 - APB in atherosclerotic aortae despite reduced expression of IP3 receptors. 4 - AP was less effective in 4 month fat fed ApoE - / - mice. Peroxynitrite relaxation involves IP3 - induced calcium release and K V channel activation. This mechanism becomes less important as atherosclerosis develops and relaxation to peroxynitrite may be maintained by increased calcium extrusion
Heating and decoherence suppression using decoupling techniques
We study the application of decoupling techniques to the case of a damped
vibrational mode of a chain of trapped ions, which can be used as a quantum bus
in linear ion trap quantum computers. We show that vibrational heating could be
efficiently suppressed using appropriate ``parity kicks''. We also show that
vibrational decoherence can be suppressed by this decoupling procedure, even
though this is generally more difficult because the rate at which the parity
kicks have to applied increases with the effective bath temperature.Comment: 13 pages, 5 figures. Typos corrected, references adde
Observing Long Colour Flux Tubes in SU(2) Lattice Gauge Theory
We present results of a high statistics study of the chromo field
distribution between static quarks in SU(2) gauge theory on lattices of volumes
16^4, 32^4, and 48^3*64, with physical extent ranging from 1.3 fm up to 2.7 fm
at beta=2.5, beta=2.635, and beta=2.74. We establish string formation over
physical distances as large as 2 fm. The results are tested against Michael's
sum rules. A detailed investigation of the transverse action and energy flux
tube profiles is provided. As a by-product, we obtain the static lattice
potential in unpreceded accuracy.Comment: 66 pages, 29 figures, uuencoded latex file with epsfigures (450 K),
supplementary full colour figures are available via ftp, CERN-TH.7413/94
(extended version
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