Bordered pit and ray morphology involvement in elm resistance to Ophiostoma novo-ulmi

2009 ◽  
Vol 39 (2) ◽  
pp. 420-429 ◽  
Author(s):  
Juan A. Martín ◽  
Alejandro Solla ◽  
Luis G. Esteban ◽  
Paloma de Palacios ◽  
Luis Gil
Keyword(s):  
Vessel Wall ◽  
Fungal Growth ◽  
Principal Component ◽  
Dutch Elm Disease ◽  
Mean Values ◽  
Anatomical Features ◽  
Wall Area ◽  
Pit Membrane ◽  
Vessel Wall Area ◽  
Component Loadings

The main objective of this study was to identify differential anatomical features between Ulmus pumila L. and Ulmus minor Mill. clones resistant to Dutch elm disease and U. minor clones susceptible to Dutch elm disease, with a focus on the intervascular pits and medullary rays. Resistant elms showed lower mean values than susceptible elms for pit membrane diameter, pit aperture area, pit membrane abundance per vessel-wall area, ray width, and ray tangential area. A principal component analysis of the parameters measured revealed slight differentiation between species but clearly grouped U. minor clones according to their susceptibility group. In comparison with susceptible elms, the pit structure observed in resistant elms may limit passive fungal spread within the sapflow, lower the probability of fungal cells passively reaching pit membranes, and reduce the vulnerability of the xylem to cavitation. Similarly, the ray structure observed in the resistant elms is likely to reduce the amount of easily accessible nutrients available for fungal growth as well as the rate of radial colonization in comparison with susceptible elms. Examination of the principal component loadings suggested that susceptible U. minor clones were mainly characterized by enhanced values of pit membrane abundance per vessel-wall area relative to resistant U. minor trees.

Abstract 348: Serial MRI Differentiates the Natural History of Stable and Vulnerable Plaques in a Rabbit Aorta

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Tuan A Pham ◽  
Ning Hua ◽  
Alkystis Phinikaridou ◽  
Nick Giordano ◽  
James A Hamilton
Keyword(s):  
Vulnerable Plaque ◽  
Vessel Wall ◽  
Rabbit Aorta ◽  
Surrounding Tissue ◽  
Black Blood ◽  
Mr Images ◽  
Wall Area ◽  
Vulnerable Plaques ◽  
Vessel Wall Area ◽  
Stable Plaque

Non-invasive monitoring of human atherosclerotic plaque progression would be extremely valuable for determining the characteristics of vulnerable plaques before they rupture and for evaluating therapeutic interventions. We have shown that MRI is a reliable method for differentiating stable and vulnerable aortic atherosclerotic plaques in a rabbit model of atherothrombosis. In this study, we imaged rabbits at 4 time points (baseline, 1, 2 and 3 months) to monitor the progression of plaques and investigate when stable and vulnerable plaques can be differentiated. MR images and histology of two plaques in the same rabbit aorta are compared below. The top row of black blood (BB) T1 images (with fat suppression) show no significant changes in the lumen or the vessel wall area, and no thrombus in the stable plaque after triggering to induce plaque rupture. The histology showed an intact fibrous cap, overlying diffuse lipids. In comparison, there is a marked increase in vessel wall area in the vulnerable plaque (from 4.1 to 15 mm2 over 3 months). The second row (T1BB FS with Gd) shows some uptake of Gd into the stable plaque and surrounding tissue, but the vulnerable plaque showed rapidly increased Gd uptake between months 2 and 3. The vulnerable plaque also showed a large luminal thrombus in the MR images of the live rabbit and in the corresponding histology slice. In addition, the vulnerable plaque showed excessive outward remodeling at 2 months (data not shown). Our study shows a progression of vulnerable features, clearly evident at 2 months, in the plaque that disrupted. We are currently investigating whether therapies initiated at 2 months will reduce the progression of plaque vulnerability.

Ultrastructural cell wall modifications in secondary xylem of American elm surviving the acute stage of Dutch elm disease: vessel members

1981 ◽  
Vol 59 (12) ◽  
pp. 2411-2424 ◽  
Author(s):  
G. B. Ouellette
Keyword(s):  
Vessel Wall ◽  
Coating Layer ◽  
Acute Stage ◽  
Dutch Elm Disease ◽  
Disease Stage ◽  
Ulmus Americana ◽  
Tree Resistance ◽  
Pit Membrane ◽  
Dense Band ◽  
Ultrastructural Characteristics

Modified vessel wall layers and their ultrastructural characteristics in branches of artificially inoculated elm (Ulmus americana L.) trees surviving the acute disease stage and of naturally infected, chronically diseased trees are described. Walls of large early-wood vessels in zones where disease action was prevalent have a strong stain reaction and may be uniformly or locally three to four times thicker than normal.In smaller vessels (some including vessel tracheids), an extra lignified-like, often discontinuous layer may be present. This layer is generally demarcated from the normal by a dense band. Pit membranes and vessel end plates are likewise much thickened through the presence of an opaque material similar to that of the pit membrane. This material differs from that forming the coating layer which like tyloses is generally present inside the thickened or extra vessel wall layer.The possible significance of these observations, particularly in relation to disease development and tree resistance, is discussed.

Reproducibility of the carotid vessel wall area and dimensions at 3.0 T MRI

2006 ◽  
Vol 45 (3) ◽  
pp. e111
Author(s):  
Reza Alizadeh Dehnavi ◽  
Joost Doornbos ◽  
Jouke T. Tamsma ◽  
Matthias Stuber ◽  
Hein Putter ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Wall Area ◽  
Vessel Wall Area ◽  
3.0 T ◽  
Carotid Vessel Wall ◽  
3.0 T Mri ◽  
Carotid Vessel

Comparison of carotid vessel wall area measurements using three different contrast-weighted black blood MR imaging techniques

2001 ◽  
Vol 19 (6) ◽  
pp. 795-802 ◽  
Author(s):  
Shaoxiong Zhang ◽  
Thomas S Hatsukami ◽  
Nayak L Polissar ◽  
Chao Han ◽  
Chun Yuan
Keyword(s):  
Mr Imaging ◽  
Vessel Wall ◽  
Imaging Techniques ◽  
Black Blood ◽  
Wall Area ◽  
Vessel Wall Area ◽  
Carotid Vessel Wall ◽  
Carotid Vessel

Tu-P9:375 Reproducibility of the carotid vessel wall area and dimensions at 3.0T MRI

2006 ◽  
Vol 7 (3) ◽  
pp. 267
Author(s):  
R. Alizadeh Dehnavi ◽  
J. Doornbos ◽  
J.T. Tamsma ◽  
M. Stuber ◽  
H. Putter ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Wall Area ◽  
Vessel Wall Area ◽  
Carotid Vessel Wall ◽  
3.0T Mri ◽  
Carotid Vessel

Studies on the Fungal Pathogen of Dutch Elm Disease

1981 ◽  
Vol 39 ◽  
pp. 400-401
Author(s):  
H.M. Mazzone ◽  
G. Wray ◽  
R. Zerillo
Keyword(s):  
Fungal Pathogen ◽  
Fungal Growth ◽  
Polymyxin B ◽  
The United States ◽  
Dutch Elm Disease ◽  
Effective Control ◽  
Sabouraud Agar ◽  
Total Inhibition ◽  
Zones Of Inhibition ◽  
Control Plate

The fungal pathogen of the Dutch elm disease (DED), Ceratocystis ulmi (Buisman) C. Moreau, has eluded effective control since its introduction in the United States more than sixty years ago. Our studies on DED include establishing biological control agents against C. ulmi. In this report we describe the inhibitory action of the antibiotic polymyxin B on the causal agent of DED.In screening a number of antibiotics against C. ulmi, we observed that filter paper discs containing 300 units (U) of polymyxin B (Difco Laboratories) per disc, produced zones of inhibition to the fungus grown on potato dextrose agar or Sabouraud agar plates (100mm x 15mm), Fig. 1a. Total inhibition of fungal growth on a plate occurred when agar overlays containing fungus and antibiotic (polymyxin B sulfate, ICN Pharmaceuticals, Inc.) were poured on the underlying agar growth medium. The agar overlays consisted of the following: 4.5 ml of 0.7% agar, 0.5 ml of fungus (control plate); 4.0 ml of 0.7% agar, 0.5 ml of fungus, 0.5 ml of polymyxin B sulfate (77,700 U). Fig. 1, b and c, compares a control plate and polymyxin plate after seven days.

Comparison of Principal Component Solutions in Two Populations

Methodology ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gregor Sočan
Keyword(s):  
Simulation Study ◽  
Principal Components ◽  
Common Factor ◽  
Principal Component ◽  
Component Model ◽  
Bootstrap Procedure ◽  
Factor Loadings ◽  
Component Loadings ◽  
Principal Component Model ◽  
Two Populations

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.

Iterative Supervised Principal Component Analysis-Driven Ligand Design for Regioselective Ti-Catalyzed Pyrrole Synthesis

2020 ◽  
Author(s):  
Xin Yi See ◽  
Benjamin Reiner ◽  
Xuelan Wen ◽  
T. Alexander Wheeler ◽  
Channing Klein ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
De Novo ◽  
Principal Component ◽  
Component Analysis ◽  
Catalyst Design ◽  
Data Driven ◽  
Initial Reaction ◽  
Training Set ◽  
Reaction Conditions ◽  
Component Loadings

<div> <div> <div> <p>Herein, we describe the use of iterative supervised principal component analysis (ISPCA) in de novo catalyst design. The regioselective synthesis of 2,5-dimethyl-1,3,4-triphenyl-1H- pyrrole (C) via Ti- catalyzed formal [2+2+1] cycloaddition of phenyl propyne and azobenzene was targeted as a proof of principle. The initial reaction conditions led to an unselective mixture of all possible pyrrole regioisomers. ISPCA was conducted on a training set of catalysts, and their performance was regressed against the scores from the top three principal components. Component loadings from this PCA space along with k-means clustering were used to inform the design of new test catalysts. The selectivity of a prospective test set was predicted in silico using the ISPCA model, and only optimal candidates were synthesized and tested experimentally. This data-driven predictive-modeling workflow was iterated, and after only three generations the catalytic selectivity was improved from 0.5 (statistical mixture of products) to over 11 (> 90% C) by incorporating 2,6-dimethyl- 4-(pyrrolidin-1-yl)pyridine as a ligand. The successful development of a highly selective catalyst without resorting to long, stochastic screening processes demonstrates the inherent power of ISPCA in de novo catalyst design and should motivate the general use of ISPCA in reaction development. </p> </div> </div> </div>

scholarly journals Genetic diversity and phylogenetic behavior of some minor legumes

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
James Oludare Agbolade ◽  
Ronke Justina Komolafe
Keyword(s):  
Genetic Diversity ◽  
Principal Component ◽  
Calyx Lobe ◽  
Descriptive Statistics ◽  
International Institute ◽  
Mean Values ◽  
Phylogenetic Relatedness ◽  
Petal Length ◽  
Morphological Differences ◽  
Range Test

Twenty-four accessions of twelve species minor legumes collected from the germplasm unit of the International Institute of Tropical Agriculture Ibadan, Nigeria were evaluated for their genetic diversities and phylogenetic relatedness. The accessions were planted into plots of 5 ridges of 5 meters long, spaced 1 meter apart and replicated three times at the Federal University Oye-Ekiti Teaching and Research Farm. The diversity and the relative phylogeny of the accessions were assessed through their floral morphological differences and the mean values between two accessions were evaluated by descriptive statistics. Principal component analysis was employed to identify the most discriminatory floral morphological traits and the similarities among the 24 accessions were assessed by cluster analysis (CA). Descriptive statistics through Duncan multiple range test adopted revealed genetic diversity and phylogenetic relatedness among the accessions. The first two principal component axes explained 64.66% of the total floral morphological variation. Standard petal length, calyx lobe length and stipule length contributed most of the variations in the legume accession. CA grouped the 24 accessions into six clusters. The study revealed intra-specific similarities and inter-specific floral morphological differences among the studied accessions.

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