Two-layered Walls Research Articles

Introducing the Rhamphoriaceae, fam. nov. (Sordariomycetes), two new genera, and new life histories for taxa with Phaeoisaria- and Idriella-like anamorphs

ABSTRACTTwo new genera, Rhamphoriopsis and Xylolentia, are described for lignicolous perithecial ascomycetes occurring in terrestrial habitats. Fresh material, living cultures, morphology, and DNA sequence data (nuc rDNA internal transcribed spacers [ITS1-5.8S-ITS2 = ITS], 18S and 28S genes, and second largest subunit of RNA polymerase II = RPB2) of these taxa and morphologically similar fungi were studied to determine their relationships. A monophyletic clade including Rhamphoria, Rhodoveronaea, a dematiaceous hyphomycete Linkosia multiseptum, and the two new genera was recovered in the Sordariomycetes based on the 18S-28S-RPB2 data set. It is introduced as the family Rhamphoriaceae and strongly supported by Bayesian and maximum likelihood methods. Its members are characterized by perithecial ascomata with a cylindrical or rostrate neck, the absence of stromatic tissue or clypeus, similar anatomy of two-layered ascomatal walls, cylindrical paraphyses, unitunicate asci with a distinct, nonamyloid apical annulus, and dictyoseptate or transversely septate, hyaline or brown ascospores. The mode of conidiogenesis is holoblastic, predominantly on polyblastic-denticulate conidiogenous cells. The Phaeoisaria-like anamorph has been linked to Rhamphoria and Rhamphoriopsis, whereas conidia and conidiophores of Idriella-like synanamorph were formed in vitro in two species of Rhamphoria. The Veronaea-like anamorph is associated with Rhodoveronaea. The anamorph of Xylolentia is a dematiaceous hyphomycete with conidiogenous cells with sympodially extending rachis. A key to members of the family is provided. The classification and nature of species boundaries in Rhamphoria are discussed, and diagnostic characters such as ascospore shape, number of transverse and longitudinal septa, a degree of constriction at the septa, and ability to produce ascoconidia are evaluated.

Optimum R-values of building walls under different climatic conditions in the Kingdom of Saudi Arabia

This paper deals with the determination of optimum R-values for building walls under different climatic conditions in the Kingdom of Saudi Arabia (KSA); namely, Riyadh, Jeddah, and Abha. One-layered and two-layered walls made of concrete and red clay blocks are considered. Molded polystyrene, polyurethane board, and rock wool are used as insulation materials. Thermal and economic analyses are carried out in order to determine the optimum insulation thickness (Lopt). The thermal analysis involves calculating temperature distribution and its variation with time across wall sections under steady periodic conditions. This is done by utilizing a previously validated computer model based on the finite-volume implicit method. Yearly transmission loads are calculated for different insulation thicknesses and used in an economic model, based on the present worth method, in order to optimize the insulation thickness and consequently determine the optimum R-values. Cooling and heating loads are separated and treated with different costs. For Riyadh and Jeddah, the optimum R-values are found in the range 2.00 to 2.90 m2.K/W, while those for Abha are found in the range 1.34 to 1.99 m2.K/W. Payback periods determined at Lopt, while considering effect of inflation and discount rates, are found in the range 3 to 10 years.

The identity of Entyloma anadelphiae: reclassification and redescription of leaf and stem smut infecting Anadelphia pumila in Guinea

The identity of a very rare smut fungus, Entyloma anadelphiae, described from infected leaves and stems of Anadelphia pumila (Poaceae, subfam. Panicoideae, tribe Andropogoneae) in Guinea is re-evaluated. Morphology indicates that this species is not identical with Jamesdicksonia dactylidis, with which it has been considered synonymous in recent smut monographs. It differs in having mostly dark brown spores with thicker, distinctly two-layered walls. Entyloma anadelphiae also differs from other smut species of the order Georgefischeriales described on hosts of the Andropogoneae. The species is redescribed, illustrated and reallocated to the genus Jamesdicksonia as a distinct species, Jamesdicksonia anadelphiae comb. nov.

Evidence for a Structural Role for Acid-Fast Lipids in Oocyst Walls of Cryptosporidium , Toxoplasma , and Eimeria

ABSTRACTCoccidia are protozoan parasites that cause significant human disease and are of major agricultural importance. Cryptosporidium spp. cause diarrhea in humans and animals, while Toxoplasma causes disseminated infections in fetuses and untreated AIDS patients. Eimeria is a major pathogen of commercial chickens. Oocysts, which are the infectious form of Cryptosporidium and Eimeria and one of two infectious forms of Toxoplasma (the other is tissue cysts in undercooked meat), have a multilayered wall. Recently we showed that the inner layer of the oocyst walls of Toxoplasma and Eimeria is a porous scaffold of fibers of β-1,3-glucan, which are also present in fungal walls but are absent from Cryptosporidium oocyst walls. Here we present evidence for a structural role for lipids in the oocyst walls of Cryptosporidium, Toxoplasma, and Eimeria. Briefly, oocyst walls of each organism label with acid-fast stains that bind to lipids in the walls of mycobacteria. Polyketide synthases similar to those that make mycobacterial wall lipids are abundant in oocysts of Toxoplasma and Eimeria and are predicted in Cryptosporidium. The outer layer of oocyst wall of Eimeria and the entire oocyst wall of Cryptosporidium are dissolved by organic solvents. Oocyst wall lipids are complex mixtures of triglycerides, some of which contain polyhydroxy fatty acyl chains like those present in plant cutin or elongated fatty acyl chains like mycolic acids. We propose a two-layered model of the oocyst wall (glucan and acid-fast lipids) that resembles the two-layered walls of mycobacteria (peptidoglycan and acid-fast lipids) and plants (cellulose and cutin).

Cryptadelphia (Trichosphaeriales), a new genus for holomorphs with Brachysporium anamorphs and clarification of the taxonomic status of Wallrothiella

The genus Cryptadelphia (Trichosphaeriales) is described for the presumed teleomorphs of six species of the dematiaceous hyphomycete genus Brachysporium. Cryptadelphia is characterized by the production of dark, leathery perithecia with two-layered walls, cylindrical, long-stipitate asci with eight hyaline, initially aseptate but ultimately 1-septate as-cospores. Zignoëlla groenendalensis is transferred to Cryptadelphia with Wallrothiella melanostigmoides as a synonym. Five new species, i.e., Cryptadelphia abietis, C. brevior, C. obovata, C. pendulispora and C. polyseptata, with their respective Brachysporium anamorphs, are described and illustrated. Phylogenetic analysis of partial large subunit rDNA sequences of two species supports the monophyly of Cryptadelphia and suggests a relationship with the Trichosphaeriales. The monophyly of the Trichosphaeriaceae and the relationships between the Trichosphaeriaceae, Annula-tascaceae and the Sordariales can be questioned, but a conclusive assessment requires phylogenetic analysis of more related taxa. The genus Wallrothiella is redescribed based on new collections of W. congregata and is characterized by the production of tiny, globose ascospores in cylindrical asci. The new collection is proposed as a neotype for the genus.

Cryptadelphia (Trichosphaeriales), a New Genus for Holomorphs with Brachysporium Anamorphs and Clarification of the Taxonomic Status of Wallrothiella

The genus Cryptadelphia (Trichosphaeriales) is described for the presumed teleomorphs of six species of the dematiaceous hyphomycete genus Brachysporium. Cryptadelphia is characterized by the production of dark, leathery perithecia with two-layered walls, cylindrical, long-stipitate asci with eight hyaline, initially aseptate but ultimately 1-septate as-cospores. Zignoëlla groenendalensis is transferred to Cryptadelphia with Wallrothiella melanostigmoides as a synonym. Five new species, i.e., Cryptadelphia abietis, C. brevior, C. obovata, C. pendulispora and C. polyseptata, with their respective Brachysporium anamorphs, are described and illustrated. Phylogenetic analysis of partial large subunit rDNA sequences of two species supports the monophyly of Cryptadelphia and suggests a relationship with the Trichosphaeriales. The monophyly of the Trichosphaeriaceae and the relationships between the Trichosphaeriaceae, Annula-tascaceae and the Sordariales can be questioned, but a conclusive assessment requires phylogenetic analysis of more related taxa. The genus Wallrothiella is redescribed based on new collections of W. congregata and is characterized by the production of tiny, globose ascospores in cylindrical asci. The new collection is proposed as a neotype for the genus.

The transient house heating condition—the building envelope response factor (BER)

In this paper influence of house walls on heating energy consumption and indoor thermal comfort was investigated. The simulations were carried out using an extended dynamical model of building-software ZID under transient conditions, like the first heating day after a long non-heating period. Four simulation cases were considered: two-layered thermal-insulation concrete house walls were used, where the thermal insulation was inserted in the inner, outer or middle positions according to the inside of the house, and one-layered concrete house walls. The influence of the house walls on internal thermal comfort and heating process is presented by two introduced factors: thermal comfort degree-hour and building envelope response factor (BER factor). This new BER factor could be a significant variable in considering house walls as a passive heating energy source. The conclusion is that under certain conditions the BER factor is at a maximum, at which point the influence of house walls on inside thermal comfort and heating energy consumption is also at a maximum.

Chlamydospores of Phytophthora cactorum: their production, structure, and infectivity

Chlamydospores of Phytophthora cactorum are described and compared with oogonia and sporangia. Chlamydospores (average diameter 39.7 μm) were generally larger than either oogonia or sporangia, were usually produced terminally on long supporting hyphae and had single, two-layered walls. They were readily formed in vitro in V8 juice broth supplemented with 2 g L−1 CaCO3 after incubation for 20 days at 4 °C. No chlamydospores were produced at 8, 12, 16, 20, or 32 °C, but chlamydospores sometimes developed at 24 and 28 °C. Chlamydospores also formed on mycelial mats buried in pasteurized potting mix after incubation for 20 days at 4 °C. Germination of chlamydospores after freezing at −23 °C for 24 h was 60–80%. Chlamydospores prepared in this way were infectious to American ginseng (Panax quinquefolium) seedlings. All 11 isolates of P. cactorum examined produced chlamydospores. Key words: Phytophthora cactorum, chlamydospores, temperature, ginseng, Panax quinquefolium.

Ultrastructure of Mycorrhizas of Dracophyllum secundum R. Br. (Ericales:Epacridaceae)

Dracophyllum secundum R. Br. (Epacridaceae) often possessed ericoid mycorrhizas; fungal endophytes formed coils within cells of the epidermis of hair-roots. The plant plasma membrane extended around the hyphae. In some epidermal cells of hair-roots, both plant and fungal cells retained their structural integrity, both partners showing mitochondrial, vacuolar and lipid droplet profiles, and with much of the plant cytoplasm associated with the hyphal coils. In other epidermal cells of hair-roots, fungal coils were present but cytoplasmic features of both symbionts appeared to have broken down. Some epidermal cells showed no evidence of fungal infection. These three arrangements could occur in root-cells of the same age, and are interpreted as resulting from different stages in the development and degeneration of the infection by the mycorrhizal fungus. Two structural types of fungal endophyte here found in ericoid mycorrhizas in D. secundum: one with simple septa, Woronin bodies and two-layered walls (presumed to be an Ascomycete), and another with dolipore septa with imperforate parenthesomes (presumed to be a Basidiomycete). The possibilities that the mycorrhizas may be seasonal, and that mycorrhizal status varies from place to place, are discussed.