The genus Distephanus (Asteraceae: Vernonieae) in southern Africa

AbstractThe southern African species of Distephanus Cass. (Asteraceae: Vernonieae) are revised. Full descriptions, illustrations, distribution maps and a key are provided for the five species recognised in the region

Taxonomic studies in the Acanthaceae: A reappraisal of the genera Duvernoia and Adhatoda in southern Africa

A reappraisal of floral and vegetative characters of southern African species of Adhatoda Miller and Duvernoia E. Mey. ex Nees is made with reference to selected tropical species of Adhatoda and to species of the closely related genus Justicia L. The generic status of Duvernoia is confirmed and the generic characters expanded. The southern African species of Adhatoda are clearly distinct from Duvernoia. Their relationship to the tropical members cannot be assessed until a full revision of the genus is undertaken. S. Afr. J. Bot. 1985, 51: 475 – 484’n Herevaluering van die blom en vegetatiewe kenmerke van Suider-Afrikaanse spesies van Duvernoia E. Mey. ex Nees en Adhatoda Miller word gedoen met verwysing na geselekteerde tropiese spesies van Adhatoda en na spesies van die naverwante genus Justicia L. Die generiese status van Duvernoia word gehandhaaf en die generiese kenmerke uitgebrei. Die Suider-Afrikaanse spesies van Adhatoda is duidelik van Duvernoia afgebaken. Totdat ‘n volledige hersiening van die genus voltooi is, kan hulle verwantskap met tropiese lede nog nie ge-evalueer word nie. S.-Afr. Tydskr. PIantk. 1985, 51: 475 – 48

The systematic significance of testa anatomy in the Leguminosae — an illustrated survey

Seed from all three subfamilies of the Leguminosae was surveyed for anatomical features of the testa which could be used in the systematics of the family. An atlas of testa anatomy is presented, and the possible adaptive significance of certain seed structures is discussed. Seed of the Mimosoideae and Caesalpinioideae remain incompletely separated, but the shape of the micropyle constitutes a useful accessory character. In addition certain genera in these subfamilies have features which are anomalous in the family. Features of the micropyle, cuticle and light line typically characterize the papilionoid seed, but the only characters invariably restricted to this subfamily are hilar features traditionally recognized as such. However, testa anatomy is very useful within the Papilionoideae and certain tribes or groups of phylogenetically related tribes can be recognized by various features of the testa, particularly cuticle sculpturing and micropyle shape. Similarities between mimosoid and caesalpinioid seeds are plesiomorphous, and cannot necessarily imply greater phylogenetic relationship. The occurrence of a direct relationship between epidermal and hypodermal thickness in papilionoid seed suggests an early stabilization of this adaptive structure

Lycium strandveldense (Solanaceae), a new species from the western coast of South Africa

A new species, L. strandveldense, from the western coastal region of the Western and Northern Cape Provinces, is described and figured. L. strandveldense, which is functionally dioecious, resembles the bisexual L. afrum L., a species also found along the western coast. Because of the near similarity in leaf and floral characteristics, specimens of L. strandveldense have in the past been regarded as atypical forms of L. afrum. This new species is distinguished by its functionally dioecious habit, relatively short, narrowly oblong, bright green leaves instead of the long, linear, glaucous leaves of L. afrum, corolla dark purple instead of claret coloured, corolla tube shorter than in L. afrum, stamens of the male flowers slightly exserted from corolla mouth in contrast to the included stamens of L. afrum, and finally a smaller ellipsoid red berry instead of the large spherical black berry of L. afrum

A taxonomic review of Cephalaria (Dipsacaceae) in the Cape Floristic Region

AbstractSix species of Cephalaria are recorded from the Cape Floristic Region (CFR), with four rare and localised species endemic to the region in the extreme southwest, and two species widely distributed in the east of the country and just entering the CFR region in the extreme east. We review these species, with full descriptions, illustrations and notes on distribution, ecology, and conservation status

Daubenya alba (Hyacinthaceae, tribe Massonieae), a new species from the Roggeveld, Northern Cape Province

Daubenya alba A.M. van der Merwe, from the edge of the Roggeveld escarpment in the Northern Cape Province, is described as a new species. It resembles D. capensis (Schltr.) A.M. van der Merwe & J.C. Manning in leaf shape, floral structure and the presence of a staminal tube, but is distinguished by its delicate white to pale lilac flowers and lack of a staminal disc

Parametric uncertainty in complex environmental models: a cheap emulation approach for models with high-dimensional output

In order to understand underlying processes governing environmental and physical processes, and predict future outcomes, a complex computer model is frequently required to simulate these dynamics. However there is inevitably uncertainty related to the exact parametric form or the values of such parameters to be used when developing these simulators, with \emph{ranges} of plausible values prevalent in the literature. Systematic errors introduced by failing to account for these uncertainties have the potential to have a large effect on resulting estimates in unknown quantities of interest. Due to the complexity of these types of models, it is often unfeasible to run large numbers of training runs that are usually required for full statistical emulators of the environmental processes. We therefore present a method for accounting for uncertainties in complex environmental simulators without the need for very large numbers of training runs and illustrate the method through an application to the Met Office's atmospheric transport model NAME. We conclude that there are two principle parameters that are linked with variability in NAME outputs, namely the free tropospheric turbulence parameter and particle release height. Our results suggest the former should be significantly larger than is currently implemented as a default in NAME, whilst changes in the latter most likely stem from inconsistencies between the model specified ground height at the observation locations and the true height at this location. Estimated discrepancies from independent data are consistent with the discrepancy between modelled and true ground height

A new Devonian euthycarcinoid reveals the use of different respiratory strategies during the marine-to-terrestrial transition in the myriapod lineage.

Myriapods were, together with arachnids, the earliest animals to occupy terrestrial ecosystems, by at least the Silurian. The origin of myriapods and their land colonization have long remained puzzling until euthycarcinoids, an extinct group of aquatic arthropods considered amphibious, were shown to be stem-group myriapods, extending the lineage to the Cambrian and evidencing a marine-to-terrestrial transition. Although possible respiratory structures comparable to the air-breathing tracheal system of myriapods are visible in several euthycarcinoids, little is known about the mechanism by which they respired. Here, we describe a new euthycarcinoid from Upper Devonian alluvio-lagoonal deposits of Belgium. Synchrotron-based elemental X-ray analyses were used to extract all available information from the only known specimen. Sulfur X-ray fluorescence (XRF) mapping and spectroscopy unveil sulfate evaporation stains, spread over the entire slab, suggestive of a very shallow-water to the terrestrial environment prior to burial consistent with an amphibious lifestyle. Trace metal XRF mapping reveals a pair of ventral spherical cavities or chambers on the second post-abdominal segment that do not compare to any known feature in aquatic arthropods, but might well play a part in air-breathing. Our data provide additional support for amphibious lifestyle in euthycarcinoids and show that different respiratory strategies were used during the marine-to-terrestrial transition in the myriapod lineage

Reduction in the structural changes of experimental osteoarthritis by a nitric oxide inhibitor

AbstractObjectiveTo evaluate the in-vivo therapeutic efficacy ofN-iminoethyl-L-Lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase (iNOS) in a dose response study, on the progression of lesions in the experimental osteoarthritic (OA) dog model.DesignThe sectioning of the anterior cruciate ligament of the right stifle joint of mongrel dogs was done by a stab wound. Dogs were separated into experimental groups: Group 1 received no treatment, Groups 2, 3, and 4 received oral L-NIL (0.3, 1 or 10mg/kg/day, respectively) starting immediately after surgery. The OA dogs were killed at 12 weeks after surgery.ResultsMacroscopically, L-NIL decreased the size of the cartilage lesions on condyles and plateaus. The histologic severity of the cartilage lesions was decreased in the L-NIL-treated dogs. This effect was more pronounced at the highest dosage tested (3 and 10mg/kg/day).ConclusionsThis study confirms the effectiveness of L-NIL, a selective inhibitor of iNOS, in attenuating the progression of experimental OA. It also clearly shows that the effect is dose-dependent