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Studies on the preservation of flowersElliott, Jennifer January 2002 (has links)
A known method for the preservation of green foliage was adapted in order to preserve floral tissues, retaining the colour and texture, thereby providing a method suitable for the preservation of whole flowers. Initially, the effects of the existing foliage preservation process on floral tissues were studied and the resulting problems of limp sticky petals and colour loss were identified. Subsequently, with a knowledge of basic plant anatomy and of the properties of the main floral pigments, the anthocyanins, a series of experiments on petals and whole flowers were carried out in an attempt to rectify these problems and to incorporate the remedies into a method for preserving whole flowers. The problem of improving the texture and firmness of flower heads was tackled by investigating the effects of adding bulking or setting ingredients to the process fluid and establishing their optimum concentrations. In the case of flower colour, the addition of acid was required in order to maintain the bright anthocyanin colours and a range of acids was investigated. Furthermore, since it is known that in nature the anthocyanin pigments are stabilised by metal ions and copigments, the use of these agents in the preservation process was also considered. This empirical work was then validated by confirming the identity of the main pigments involved and by studying various aspects of the new preservation process. Factors examined included acid concentration, temperature, solvent composition and the addition of metal ions and copigments to solutions of petal extracts containing anthocyanin pigments. Physical changes resulting from processing, including process fluid content and the moisture absorption properties of processed petals were also measured. Finally, the application of a selection of coating materials was assessed in an attempt to increase the life span of the processed flowers by providing extra protection against environmental stresses.
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A critical assessment of the dendrochirotid subfamilies, sclerodactylinae and thyoninae, with the taxonomic management of the "supergenus" thyone (echinodermata : holothuroidea)Arumugam, Preyan. 10 October 2013 (has links)
The key character separating the dendrochirotid families Sclerodactylidae (sensu
Pawson & Fell, 1965) and the Phyllophoridae (sensu Pawson & Fell, 1965), i.e. entire
or undivided radial processes to the calcareous ring in the former and sub-divided
processes in the latter, is unjustified since most sclerodactylid species also have subdivided
processes. It is here assumed that the basis of elevating the subfamily
Sclerodactylinae Panning to family level was established on a misinterpretation or
mistranslation of the original diagnosis of this subfamily or a lapsus calumni meaning
“plates” instead of “processes”. Panning (1949) categorically states that the processes in
the Sclerodactylinae are composed of 3–4 large pieces of calcite and only as an
exception they are unbroken. Since Pawson & Fell gave no other distinction between
the Sclerodactylidae and the Phyllophoridae, the former is here considered an invalid
taxon and its three current subfamilies (Sclerodactylinae, Sclerothyoninae Thandar and
Cladolabinae Heding & Panning) are re-assigned to the Phyllophoridae. This family
now includes six subfamilies: Cladolabinae, Phyllophorinae Östergren,
Sclerodactylinae, Sclerothyoninae, Semperiellinae Heding & Panning and Thyoninae
Panning. The diagnosis of the Sclerodactylinae, restricted by Thandar (1989), is now
modified to include also those forms whose radial and interradial plates may be slightly
sub-divided but still form a short tube. Of the eleven genera placed within this
subfamily subsequent to its erection, only ten of these remain. Neothyone Deichmann is
a preoccupied name for which Lisacucumis is here proposed as a replacement.
Thandar’s (1989) diagnosis of the Thyoninae is here accepted, however, the genus
Thorsonia Heding is transferred to the Sclerodactylinae. Of the 66 nominal species
which currently stand in the “supergenus” Thyone Jaeger, 10 are transferred to
Havelockia Pearson within the Sclerodactylinae, while one species is regarded as a
synonym of H. herdmani Pearson. In addition, six species are transferred to Stolus
Selenka within the Thyoninae. Finally, three species are transferred to Sclerothyoninae,
two within Sclerothyone Thandar and one within Temparena Thandar. Two species
show an uncertain affinity to Thyone and are temporally removed from the genus.
Furthermore, two species currently classified within Havelockia are transferred to
Thyone. The now remaining 46 species are separated into seven groups based on the
composition of their introvert deposits: tables only (8 spp.), rosettes only (5 spp.), tables
and rosettes (21 spp.), tables and plates/?reduced tables (2 spp.), rosettes and
plates/?reduced tables (3 spp.), plates only (2 spp.), or introvert deposits absent or
unknown (5 spp.). Regrettably, no other character could be used in conjunction with the
above to suggest at least sub-generic levels. Within the genus Havelockia, Cucumaria
redimita Sluiter indicates an affinity with Pentamera Ayres. It is here transferred to this
genus within the Thyoninae. Havelockia, now containing 17 species, is also revised.
Keys, diagnoses and figures are provided for all nominal species now included in
Thyone and Havelockia. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.
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