Characterization of Canadian and European Melanconium from some Alnus species by morphological, cultural, and biochemical studies

1991 ◽  
Vol 69 (10) ◽  
pp. 2170-2176 ◽  
Author(s):  
T. N. Sieber ◽  
F. Sieber-Canavesi ◽  
O. Petrini ◽  
A. K. M. Ekramoddoullah ◽  
C. E. Dorworth

Melanconium apiocarpum (anamorph of Melanconis alni), Melanconium marginale (anamorph of Melanconis marginalis), and other Melanconium species isolated from healthy and diseased tissues of Alnus species in Canada, England, and Switzerland were compared by means of morphological, cultural, and biochemical techniques, and the results were analyzed by numerical methods. No differences were recorded between symptomless endophytes and disease syndrome associated isolates of M. apiocarpum, although European and Canadian isolates could be consistently and clearly differentiated by protein profiles and cellulose utilization patterns. On the basis of cultural and biochemical characters as well as conidia morphology, M. apiocarpum and M. marginale are distinct species. Two intraspecific groups of M. marginale, particular to separate Alnus species, were identified. Melanconium isolates from Fagus sylvatica and Quercus robur are clearly distinct from those on Alnus. Key words: Melanconium, Melanconis, Alnus, numerical taxonomy.

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Antonino Laudani ◽  
Francesco Riganti Fulginei ◽  
Alessandro Salvini ◽  
Gabriele Maria Lozito ◽  
Salvatore Coco

In recent years several numerical methods have been proposed to identify the five-parameter model of photovoltaic panels from manufacturer datasheets also by introducing simplification or approximation techniques. In this paper we present a fast and accurate procedure for obtaining the parameters of the five-parameter model by starting from its reduced form. The procedure allows characterizing, in few seconds, thousands of photovoltaic panels present on the standard databases. It introduces and takes advantage of further important mathematical considerations without any model simplifications or data approximations. In particular the five parameters are divided in two groups, independent and dependent parameters, in order to reduce the dimensions of the search space. The partitioning of the parameters provides a strong advantage in terms of convergence, computational costs, and execution time of the present approach. Validations on thousands of photovoltaic panels are presented that show how it is possible to make easy and efficient the extraction process of the five parameters, without taking care of choosing a specific solver algorithm but simply by using any deterministic optimization/minimization technique.


2002 ◽  
Vol 80 (11) ◽  
pp. 1524-1529 ◽  
Author(s):  
Tianle Zhang ◽  
Warren E Piers ◽  
Masood Parvez

Reaction of McConville's chelating amido titanium complex [(Ar)NCH2CH2CH2N(Ar)]Ti(CH3)2 (Ar = 2,6-i-Pr2C6H3) with either elemental Se or the tellurium atom source Te=PBu3 resulted in the formation of bis-µ-chalcogenido dimers [(Ar)NCH2CH2CH2N(Ar)]2Ti(µ-E)2 (E = Se, 2; Te, 3) with concommitant loss of EMe2. The dimers 2 and 3 were characterized spectroscopically and via X-ray crystallography. The two compounds are isostructural in the solid state. The tellurido dimer 3 may also be synthesized by reduction of the diamido dichloride [(Ar)NCH2CH2CH2N(Ar)]2TiCl2 with Na–Hg amalgam followed by treatment with Te=PBu3. This dimer is unreactive toward further Te=PBu3 or stannanes such as HSnBu3. Unlike decamethyltitanocene derivatives, the diamido complex is not an effective catalyst precursor for the heterohydrodecoupling of Te=PBu3 and HSnBu3.Key words: diamido titanium complexes, selenides, tellurides.


Phytotaxa ◽  
2021 ◽  
Vol 527 (3) ◽  
pp. 161-176
Author(s):  
NATALY QUIROZ-GONZÁLEZ ◽  
MA. EDITH PONCE-MÁRQUEZ ◽  
NORMA LÓPEZ-GÓMEZ ◽  
DENÍ RODRÍGUEZ

Gelidium pusillum is a species reported from the northern Gulf of California to the tropical region of the Mexican Pacific, but there is wide morphological variation among populations. The objective of this research was to evaluate of the Mexican species using morphological and molecular approaches, with the markers rbcL and COI-5P. This study examined 12 samples from four sites in the Mexican tropical Pacific. Phylogenetic analyses resolved these specimens within two clades separated from the topotype material of G. pusillum. The main morphological differences with other Mexican and phylogenetic closely related species were size, branching pattern, branching order, distribution of internal rhizoidal filaments, and shape of the tetrasporangial sori. The sequence divergences between these clades and the morphological differences support their representing distinct species so that Gelidium nayaritense sp. nov. is proposed for tropical specimens of the Mexican Pacific, whose diagnostic characteristics are the little or absent branching, its small size, as well as the presence of internal rhizoidal filaments concentrated in the subcortex, further G. sanyaense is register for first time from Mexico and Eastern Pacific.


Sign in / Sign up

Export Citation Format

Share Document