Morphological and Ultrastructural Studies of Plant Cuticular Membranes. I. Sun and Shade Leaves of Quercus velutina (Fagaceae)

This is the publisher's version, also available electronically from http://www.jstor.org.Sun and shade leaves of Quercus velutina Lam. were evaluated with respect to differences in gross anatomy, morphology, and cuticle (cuticular membrane (CM|) ultrastructure and micromorphology. Sun leaves are smaller, with more deeply lobed margins, and have more stomata, thicker mesophylls, and thicker CMs when compared with shade leaves. Cuticular membranes are thicker on both the adaxial and abaxial surfaces of sun leaves as a result of deposition of more cuticular components and scaly epicuticular wax. Both the adaxial and abaxial epidermises have the same basic fine structure in sun and shade leaves with respect to the outer periclinal cell wall and overlying CM. The cell wall is lamellate and the CM is composed of a two-zoned, reticulate cuticular layer and an amorphous cuticle proper. The outer periclinal wall and associated CM of the adaxial epidermis is thicker than that of the abaxial epidermis with both epidermal layers thicker in sun leaves compared with shade leaves. Difference in thickness of both epidermal layers, between sun and shade leaves, can be attributed to an increase in the inner reticulate region of the CM of sun leaves. Cells of the abaxial epidermis have ultrastructurally different CMs. Nonstomatal epidermal cells have a distinct amorphous cuticle proper whereas subsidiary cells have reticulations that traverse most of the outer CM. Guard cells have radially aligned reticulations through the entire outer CM and, therefore, lack an amorphous cuticle proper. Moreover, an internal CM, which is only sparsely reticulate, lines substomatal chambers. The internal CM of sun leaves is thicker and extends considerably deeper into substomatal chambers

Renormalization Group and Infinite Algebraic Structure in D-Dimensional Conformal Field Theory

We consider scalar field theory in the D-dimensional space with nontrivial metric and local action functional of most general form. It is possible to construct for this model a generalization of renormalization procedure and RG-equations. In the fixed point the diffeomorphism and Weyl transformations generate an infinite algebraic structure of D-Dimensional conformal field theory models. The Wilson expansion and crossing symmetry enable to obtain sum rules for dimensions of composite operators and Wilson coefficients.Comment: 16 page

Conformal anomaly of Wilson surface observables - a field theoretical computation

We make an exact field theoretical computation of the conformal anomaly for two-dimensional submanifold observables. By including a scalar field in the definition for the Wilson surface, as appropriate for a spontaneously broken A_1 theory, we get a conformal anomaly which is such that N times it is equal to the anomaly that was computed in hep-th/9901021 in the large N limit and which relied on the AdS-CFT correspondence. We also show how the spherical surface observable can be expressed as a conformal anomaly.Comment: 18 pages, V3: an `i' dropped in the Wilson surface, overall normalization and misprints corrected, V4: overall normalization factor corrected, references adde

Individual and area-level risk factors for suicidal ideation and attempt in people with severe depression

INTRODUCTION: Previous research has identified several risk factors that are strongly associated with suicidal behavior in patients with severe depression. However, the effects of area-level characteristics on suicidal ideation and attempt in this population remain unclear. METHODS: The Clinical Record Interactive Search (CRIS) database was used to identify 2587 patients with severe depression who received secondary mental health services from the Camden & Islington NHS Foundation Trust. Stepwise multivariable logistic regression models were used to examine associations between socio-demographic characteristics, clinical variables, area-level measures, and suicidal ideation and attempt as separate outcomes. RESULTS: Both suicidal ideation and attempts were common among this cohort of severely depressed individuals (70.5% and 37.7%, respectively). While several individual socio-demographic and clinical characteristics were associated with both outcomes, particularly past psychiatric admission (suicidal ideation: adjusted OR=2.86, 95% CI: 2.26-3.62; suicide attempt: adjusted OR=4.00, 95% CI: 3.30-4.89), neither social deprivation nor ethnic density (measured at the area-level) was associated with risk for either outcome. LIMITATIONS: Data were not collected specifically for research purposes and hence information on some potential confounders was not available. Additionally, information was restricted to individuals who accessed secondary mental health services in a defined catchment area and period. The study therefore does not take into account individuals who did not access mental health services. CONCLUSIONS: The variation in risk for suicidal ideation and attempt among severely depressed individuals is explained by differences in individual socio-demographic and clinical characteristics, most notably past psychiatric admission and substance misuse, and not by area-level measures

Palaeofibulus Gen. nov., a Clamp-Bearing Fungus from the Triassic of Antarctica

No abstract is available for this item

Calorons and localization of quark eigenvectors in lattice QCD

We analyze the localization properties for eigenvectors of the Dirac operator in quenched lattice QCD in the vicinity of the deconfinement phase transition. Studying the characteristic differences between the Z_3 sectors above the critical temperature T_c, we find indications for the presence of calorons.Comment: 4 pages, 4 figure

Preparation and ring-opening reactions of N-diphenylphosphinyl vinyl aziridines

Predominantly (E)-N-diphenylphosphinyl vinyl aziridines are prepared by a reaction of N-diphenylphosphinyl imines with α-bromoallyllithium in the presence of freshly fused ZnCl2. These aziridines undergo a ring-opening reaction with a variety of carbon and heteronucleophiles, in good yield, and generally with good regioselectivity

The QCD sign problem and dynamical simulations of random matrices

At nonzero quark chemical potential dynamical lattice simulations of QCD are hindered by the sign problem caused by the complex fermion determinant. The severity of the sign problem can be assessed by the average phase of the fermion determinant. In an earlier paper we derived a formula for the microscopic limit of the average phase for general topology using chiral random matrix theory. In the current paper we present an alternative derivation of the same quantity, leading to a simpler expression which is also calculable for finite-sized matrices, away from the microscopic limit. We explicitly prove the equivalence of the old and new results in the microscopic limit. The results for finite-sized matrices illustrate the convergence towards the microscopic limit. We compare the analytical results with dynamical random matrix simulations, where various reweighting methods are used to circumvent the sign problem. We discuss the pros and cons of these reweighting methods.Comment: 34 pages, 3 figures, references added, as published in JHE