XTH acts at the microfibril-matrix interface during cell elongation

Sulphorhodamine-labelled oligosaccharides of xyloglucan are incorporated into the cell wall of Arabidopsis and tobacco roots, and of cultured Nicotiana tabacum cells by the transglucosylase (XET) action of XTHs. In the cell wall of diffusely growing cells, the subcellular pattern of XET action revealed a 'fibrillar' pattern, different from the xyloglucan localization. The fibrillar fluorescence pattern had no net orientation in spherical cultured cells. It changed to transverse to the long axis when the cells started to elongate, a feature mirroring the rearrangements of cortical microtubules and the accompanying cellulose deposition. Interference with the polymerization of microtubules and with cellulose deposition inhibited this strong and 'fibrillar'-organized XET-action, whereas interference with actin-polymerization only decreased the intensity of enzyme action. Epidermal cells of a mutant with reduced cellulose synthesis also had low XET action. Root hairs (tip-growing cells) exhibited high XET-action over all their length, but lacked the specific parallel pattern. In both diffuse- and tip-growing cell types extraction of the incorporated fluorescent xyloglucans by a xyloglucan-specific endoglucanase reduced the fluorescence, but the 'fibrillar' appearance in diffuse growing cells was not eliminated. These results show that XTHs act on the xyloglucans attached to cellulose microfibrils. After incorporation of the fluorescent oligosaccharides, the xyloglucans decorate the cellulose microfibrils and become inaccessible to hydrolytic enzymes

Overuse syndrome and the overuse concept

This is the third in a series of working papers designed to promote discussion about the pathological basis of work-related neck and upper limb disorders. The ultimate aim of the papers is to allow some resolution about pathology to be achieved, so that diagnoses can be more accurate and treatments more useful. The first two papers in this series "The neurogenic hypothesis of RSI" by John Quintner and Bob Elvey (I) and "The relevance of concepts of hyperalgesia to "RSI" by Milton Cohen, Jesus Arroyo and David Champion (2) concentrated on the nervous system. This paper "Overuse syndrome and the overuse concept" by Hunter Fry examines pathology in muscles. There are 12 commentaries which add supporting information and/or probe potential weaknesses and these are then responded to by Hunter Fry

QED in strong, finite-flux magnetic fields

Lower bounds are placed on the fermionic determinants of Euclidean quantum electrodynamics in two and four dimensions in the presence of a smooth, finite-flux, static, unidirectional magnetic field $B(r) =(0,0,B(r))$, where $B(r) \geq 0$ or $B(r) \leq 0$, and $r$ is a point in the xy-plane.Comment: 10 pages, postscript (in uuencoded compressed tar file

Farewell Daisy Bell

https://digitalcommons.library.umaine.edu/mmb-vp/5178/thumbnail.jp

Evolution of hierarchical clustering in the CFHTLS-Wide since z~1

We present measurements of higher order clustering of galaxies from the latest release of the Canada-France-Hawaii-Telescope Legacy Survey (CFHTLS) Wide. We construct a volume-limited sample of galaxies that contains more than one million galaxies in the redshift range 0.2<z<1 distributed over the four independent fields of the CFHTLS. We use a counts in cells technique to measure the variance and the hierarchical moments S_n = /^(n-1) (3<n<5) as a function of redshift and angular scale.The robustness of our measurements if thoroughly tested, and the field-to-field scatter is in very good agreement with analytical predictions. At small scales, corresponding to the highly non-linear regime, we find a suggestion that the hierarchical moments increase with redshift. At large scales, corresponding to the weakly non-linear regime, measurements are fully consistent with perturbation theory predictions for standard LambdaCDM cosmology with a simple linear bias.Comment: 17 pages, 11 figures, submitted to MNRA

Advanced study of coastal zone oceanographic requirements for ERTS E and F

Earth Resources Technology Satellites E and F orbits and remote sensor instruments for coastal oceanographic data collectio

Constraints on Galaxy Bias, Matter Density, and Primordial Non--Gausianity from the PSCz Galaxy Redshift Survey

We compute the bispectrum for the \IRAS PSCz catalog and find that the galaxy distribution displays the characteristic signature of gravity. Assuming Gaussian initial conditions, we obtain galaxy biasing parameters $1/b_1=1.20^{+0.18}_{-0.19}$ and $b_2/b_1^2=-0.42\pm0.19$, with no sign of scale-dependent bias for $k\leq 0.3$ h/Mpc. These results impose stringent constraints on non-Gaussian initial conditions. For dimensional scaling models with $\chi^2_N$ statistics, we find N>49, which implies a constraint on primordial skewness $B_3<0.35$.Comment: 4 pages, 3 embedded figures, uses revtex style file, minor changes to reflect published versio

Baryogenesis via lepton number violating scalar interactions

We study baryogenesis through lepton number violation in left-right symmetric models. In these models the lepton number and CP violating interactions of the triplet higgs scalars can give rise to lepton number asymmetry through non-equilibrium decays of the $SU(2)_L$ triplet higgs and the right handed neutrinos. This in turn generates baryon asymmetry during the electroweak anomalous processes.Comment: 14 pages, UTPT-93-1

Redshift-Space Distortions with the Halo Occupation Distribution I: Numerical Simulations

We show how redshift-space distortions of the galaxy correlation function or power spectrum can constrain the matter density parameter Omega_m and the linear matter fluctuation amplitude sigma_8. We improve on previous treatments by adopting a fully non-linear description of galaxy clustering and bias, which allows us to break parameter degeneracies by combining large-scale and small- scale distortions. We consider different combinations of Omega_m and sigma_8 and find parameters of the galaxy halo occupation distribution (HOD) that yield nearly identical galaxy correlation functions in real space. We use these HOD parameters to populate the dark matter halos of large N-body simulations, from which we measure redshift-space distortions on small and large scales. We include a velocity bias parameter alpha_v that allows the velocity dispersions of satellite galaxies in halos to be systematically higher or lower than those of dark matter. Large-scale distortions are determined by the parameter combination beta = Omega_m^{0.6}/b_g, where b_g is the galaxy bias, in agreement with linear theory. However, linear theory does not accurately describe the distortions themselves on scales accessible to our simulations. We provide fitting formulas to estimate beta from the redshift-space correlation function or power spectrum, and we show that these formulas are significantly more accurate than those in the existing literature. On small scales, the ``finger-of-god'' distortions at projected separations ~0.1 Mpc/h depend on Omega_m*alpha_v^2 but are independent of sigma_8, while at intermediate separations they depend on sigma_8 as well. One can thus use redshift-space distortions over a wide range of scales to separately determine Omega_m, sigma_8, and alpha_v. (Abridged)Comment: 25 pages, submitted to Monthly Notice