Production of aqueous colloidal dispersions of carbon nanotubes.

The Layer Silicates

Preparation and properties of monodispersed colloidal particles of lanthanide compounds: I. Gadolinium, europium, terbium, samarium, and cerium(III)

Properties of Copper Chromite Catalysts in Hydrogenation Reactions

This paper is concerned with the cross-linking of poly(vinyl alcohol) (PVA) using maleic acid as the cross-linker. The curative (maleic acid) dose and the curing temperature and time were varied between 2.5 and 60% (w/w), 120 and 160 °C and 30 and 120 min, respectively. From a thorough swelling study in both hot and cold water (percentage swelling, gel content, swelling ratio, etc-) the optimum curative dose and curing conditions have been evaluated. The molecular weight between the cross-links exhibited a sharp fall up to a maleic acid dose of 20% (w/w). A comparative evaluation of maleic acid cross-linked and heat-treated PVA films has been done. Better heat stability for maleic acid cross-linked PVA was observed from thermogravimetric analysis. A shift in glass transition temperature was observed for both heat-treated and maleic acid treated PVA compared with the virgin one. IR spectroscopic study indicated the presence of an ester linkage and an olefinic double bond in maleic acid treated and heat-treated PVA films, respectively. Maleic acid cross-linked PVA is quite stable in different polar and nonpolar solvents. A definite structural pattern has been observed in maleic acid cross-linked PVA films through scanning electron microscopy.

Studies On The Crosslinking Of Poly (Vinyl Alcohol)

Infrared Absorption Spectroscopy

Analyses of cpDNA using maximum parsimony, maximum likelihood and Bayesian inference reveal that Metastelma is polyphyletic in its present circumscription. Two species are transferred to Tassadia as T. richardiana and T. stricta. One species, M. eggersii, is retrieved as a member of subtribe Gonolobinae rather than Metastelmatinae, and several South American species fall within the “Stelmation” clade together with species of Ditassa. In Metastelma sensu stricto, the South American species are not monophyletic, falling into a M. tubatum Clade and a South American-Caribbean M. parviflorum Clade. Most Caribbean species, except for M. anegadense, M. decipiens, M. lineare, and M. parviflorum, form a clade in which the Cuban species are sister to the remaining taxa. The Central American mainland species show a clear geographical structure with a center of diversity in central Mexico, two radiations along the Occidental portion of Sierra Madre, and one radiation along the Oriental portion of Sierra Madr...

https://bioone.org/journals/systematic-botany/volume-39/issue-2/036364414X680708/Phylogenetics-and-Biogeography-of-the-Genus-Metastelma-Apocynaceae-Asclepiadoideae-Asclepiadeae/10.1600/036364414X680708.pdf

Phylogenetics and Biogeography of the Genus Metastelma (Apocynaceae-Asclepiadoideae-Asclepiadeae: Metastelmatinae)

Combined molecular and morphological analyses demonstrate that a number of small-flowered Caribbean Asclepiadoideae of hitherto uncertain affiliation form two independent lineages in Asclepiadeae—Gonolobinae, and not, as previously assumed, in the Metastelmatinae. One lineage is described as the new genus Anemotrochus, which includes the widespread Caribbean A. eggersii, a species originally described under Metastelma; A. yamanigueyensis, a new species discovered by the authors in E Cuba; and A. viridivenius, a plant from Hispaniola formerly assigned to Matelea. The second lineage, Tylodontia, is a small genus restricted to Cuba. Besides its type species, T. cubensis, the genus comprises T. fuscula, a species formerly assigned to Metastelma; T. stipitata, a new species described here; and T. urceolata, a species formerly assigned to Astephanus. Anemotrochus and Tylodontia belong to the wider Matelea alliance, but they form endemic Antillean, mainly Cuban lineages independent from Matelea. All sp...

/pdf/phylogeny-and-circumscription-of-antillean-anemotrochus-gen-2n3undui2l.pdf

Phylogeny and circumscription of Antillean Anemotrochus, gen. nov., and Tylodontia (Apocynaceae: Asclepiadoideae: Gonolobinae)

Species of tropical tar spot fungi (Phyllachorales, Ascomycota) are obligate biotrophic plant parasitic fungi associated with living leaves of a wide range of families of host plants, mainly in tropical and subtropical regions. In this study, samples of tropical tar spot fungi were collected in forests in Costa Rica and Panama. To identify taxa, we used morphology and information on host plants and combined multigene phylogeny of four genes: the large subunit nuclear ribosomal DNA (28S rDNA), the small subunit nuclear ribosomal DNA (18S rDNA), the complete internal transcribed spacer region of ribosomal DNA (nuc rDNA ITS1-5.8S-ITS2; ITS), and the translation elongation factor 1-α (tef1). Here we propose one new species in the genus Camarotella and eight new species in Telimena with their morphological descriptions, illustrations, and sequence data. The newly described species are Camarotella licaniae on Licania arborea (Chrysobalanaceae) and in the genus Telimena: T. billiae on Billia rosea (Sapindaceae), T. drymoniae on Drymonia multiflora (Gesneriaceae), T. hydrangeae on Hydrangea sp. (Hydrangeaceae), T. miravallensis on Symplocos panamensis (Symplocaceae), T. protii on Protium sp. (Burseraceae), T. rinoreae on Rinorea sp. (Violaceae), T. semialarii on Semialarium mexicanum (Celastraceae), and T. triseptata on Tapirira mexicana (Anacardiaceae). The new name Telimena nitens on Schlegelia brachyanta (Schlegeliaceae) is presented and 10 species of Phyllachora are transferred to Telimena, leading to the new combinations T. canarii, T. galavisii, T. insueta, T. ruelliae, T. scutiformis, T. serjaniicola, T. spicatae, T. subrepens, T. symploci, and T. symplocicola. Additionally, revisions of tar spot fungi on host families Burseraceae, Sapindaceae, and Symplocaceae are provided, and four new synonyms are proposed.

New neotropical species of Phyllachorales based on molecular, morphological, and ecological data.

The occurrence of rust fungi (Basidiomycota) infecting vascular plants on 14 sites in western Panama differing in altitude, climate, and vegetation type was analyzed. Three vegetation-types are investigated: (1) Disturbed sites where Asteraceae, Fabaceae, and Poaceae are most speciose, (2) slightly disturbed high canopy forests with sparse herbaceous undergrowth and no dominant plant family, and (3) relatively undisturbed forests with rich herbaceous undergrowth where Orchidaceae and ferns are most speciose. The majority of species of Pucciniales were found in disturbed sites on Asteraceae, Cyperaceae, Fabaceae, and Poaceae, whereas high canopy forests with sparse herbaceous layers yielded only few species of Pucciniales that were not common on any specific plant family. In undisturbed forests, a higher number of Pucciniales was found infecting mostly pteridophytes and Orchidaceae. Generally, undisturbed sites yielded a lower number of Pucciniales in relation to the number of plant species of which several species have a wide host range within the same site, and a low percentage of samples containing teliospores. Disturbed sites yielded a high number of Pucciniales in relation to the number of plant species, many rusts having a wide geographical distribution and a wide host range outside the sites, and a higher percentage of samples containing teliospores.

Ralph D. Mangelsdorff

Papers

Infrared Absorption Spectroscopy

Phylogenetics and Biogeography of the Genus Metastelma (Apocynaceae-Asclepiadoideae-Asclepiadeae: Metastelmatinae)

Phylogeny and circumscription of Antillean Anemotrochus, gen. nov., and Tylodontia (Apocynaceae: Asclepiadoideae: Gonolobinae)

New neotropical species of Phyllachorales based on molecular, morphological, and ecological data.

Correlation of diversity of rust fungi and their host plants with disturbance and conservation of vegetation in western Panama