287 research outputs found
Changes in Carbohydrates in Nursery-Grown Grapevine Rootstocks
The utilisation and accumulation of sugar, starch and hemicellulose were studied in nursery-grown grapevine rootstocks. For an initial period lasting about 12 weeks all three components were utilised to varying degrees by the cuttings. Subsequently, starch and hemicellulose increased in the stem (original cutting) of the plant, while sugar remained low until the onset of winter. In the shoots, hemicellulose accumulation was very marked, whereas in the roots starch was the dominant carbohydrate component
A clinical delineation of Tachyphemia (cluttering)
Cluttering constitutes one of the most important disorders of speech, language and communication in general. The majority of c1utterers are themselves unaware of the disorder. The problems of definition, symptomatology, aetiology and relationship to stuttering and hereditary aspects, are discussed. A preliminary case report of a family in which cluttering appears to follow a dominant mode of inheritance, is given. It is concluded that the major symptoms underlying the general cluttering syndrome in the family described, are related to some form of psychoneurological dysfunction with emphasis on a central language imbalance.S. Afr. Med. J., 48, 1624 (1974
Intra-osseous synovial sarcoma.
Intra-osseous synovial sarcoma is very rare and its mode of origin is conjectural. Our patient's tumour was situated within the lower femur. The sited of origin of the few intra-osseous synovial sarcomas so far documented may support the concept of intra-osseous synovial rests
Decoherence due to elastic Rayleigh scattering
We present theoretical and experimental studies of the decoherence of
hyperfine ground-state superpositions due to elastic Rayleigh scattering of
light off-resonant with higher lying excited states. We demonstrate that under
appropriate conditions, elastic Rayleigh scattering can be the dominant source
of decoherence, contrary to previous discussions in the literature. We show
that the elastic-scattering decoherence rate of a two-level system is given by
the square of the difference between the elastic-scattering \textit{amplitudes}
for the two levels, and that for certain detunings of the light, the amplitudes
can interfere constructively even when the elastic scattering \textit{rates}
from the two levels are equal. We confirm this prediction through calculations
and measurements of the total decoherence rate for a superposition of the
valence electron spin levels in the ground state of Be in a 4.5 T
magnetic field.Comment: 5 pages, 3 figure
Scalable ion traps for quantum information processing
We report on the design, fabrication, and preliminary testing of a 150 zone
array built in a `surface-electrode' geometry microfabricated on a single
substrate. We demonstrate transport of atomic ions between legs of a `Y'-type
junction and measure the in-situ heating rates for the ions. The trap design
demonstrates use of a basic component design library that can be quickly
assembled to form structures optimized for a particular experiment
Spectroscopy and Thermometry of Drumhead Modes in a Mesoscopic Trapped-Ion Crystal using Entanglement
We demonstrate spectroscopy and thermometry of individual motional modes in a
mesoscopic 2D ion array using entanglement-induced decoherence as a method of
transduction. Our system is a 400 m-diameter planar crystal of
several hundred Be ions exhibiting complex drumhead modes in the
confining potential of a Penning trap. Exploiting precise control over the
Be valence electron spins, we apply a homogeneous spin-dependent
optical dipole force to excite arbitrary transverse modes with an effective
wavelength approaching the interparticle spacing (20 \nolinebreakm).
Center-of-mass displacements below 1 nm are detected via entanglement of spin
and motional degrees of freedom.Comment: 12 pages, 7 figures (includes Supplementary Material
Myomegalin is a novel A-kinase anchoring protein involved in the phosphorylation of cardiac myosin binding protein C
<p>Abstract</p> <p>Background</p> <p>Cardiac contractility is regulated by dynamic phosphorylation of sarcomeric proteins by kinases such as cAMP-activated protein kinase A (PKA). Efficient phosphorylation requires that PKA be anchored close to its targets by A-kinase anchoring proteins (AKAPs). Cardiac Myosin Binding Protein-C (cMyBPC) and cardiac troponin I (cTNI) are hypertrophic cardiomyopathy (HCM)-causing sarcomeric proteins which regulate contractility in response to PKA phosphorylation.</p> <p>Results</p> <p>During a yeast 2-hybrid (Y2H) library screen using a trisphosphorylation mimic of the C1-C2 region of cMyBPC, we identified isoform 4 of myomegalin (MMGL) as an interactor of this N-terminal cMyBPC region. As MMGL has previously been shown to interact with phosphodiesterase 4D, we speculated that it may be a PKA-anchoring protein (AKAP).</p> <p>To investigate this possibility, we assessed the ability of MMGL isoform 4 to interact with PKA regulatory subunits R1A and R2A using Y2H-based direct protein-protein interaction assays. Additionally, to further elucidate the function of MMGL, we used it as bait to screen a cardiac cDNA library. Other PKA targets, viz. CARP, COMMD4, ENO1, ENO3 and cTNI were identified as putative interactors, with cTNI being the most frequent interactor.</p> <p>We further assessed and confirmed these interactions by fluorescent 3D-co-localization in differentiated H9C2 cells as well as by <it>in vivo </it>co-immunoprecipitation. We also showed that quantitatively more interaction occurs between MMGL and cTNI under β-adrenergic stress. Moreover, siRNA-mediated knockdown of MMGL leads to reduction of cMyBPC levels under conditions of adrenergic stress, indicating that MMGL-assisted phosphorylation is requisite for protection of cMyBPC against proteolytic cleavage.</p> <p>Conclusions</p> <p>This study ascribes a novel function to MMGL isoform 4: it meets all criteria for classification as an AKAP, and we show that is involved in the phosphorylation of cMyBPC as well as cTNI, hence MMGL is an important regulator of cardiac contractility. This has further implications for understanding the patho-aetiology of HCM-causing mutations in the genes encoding cMyBPC and cTNI, and raises the question of whether MMGL might itself be considered a candidate HCM-causing or modifying factor.</p
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