Search

The possibility that the fossils attributed to Australopithecus africanus represent more than a single species is of significance because of the pivotal role that A. africanus has played in discussions about hominin evolution. The A. africanus hypodigm that is currently widely recognized evinces considerable variation in a number of craniodental characters, and this has led to speculation that more than one australopith taxon may be represented among the specimens from Sterkfontein. Although crania, mandibles and teeth have dominated these taxonomic discussions, the Sterkfontein postcranial remains also have been invoked. While several workers have proposed that some of the craniodental remains from Sterkfontein can be partitioned into two groups, there is a notable lack of agreement among them as to their actual sorting. Most of the craniodental observations that have been put forward in support of arguments for taxonomic heterogeneity of the Sterkfontein australopith assemblage have been subjective and anecdotal in nature. So too, the postcranial evidence that has been cited in support of more than one australopith species at Sterkfontein has been largely subjective, and limited to a small number of elements. The results of quantitative statistical analyses of the craniodental and postcranial fossils that have been undertaken to date are not necessarily consistent with the hypothesis of taxonomic heterogeneity. [ABSTRACT FROM AUTHOR]

This paper presents the summary of checklists, surveys and/or significant references for the ten Canadian provinces and three territories and the 50 American states. The data for this paper are based on the author's work covering over 50 years of collections and reported in 116 publications. This summary includes ten families, 43 genera and 193 species. Maps for the locations of the Canadian provinces and territories and the American states are included in the appendices. [ABSTRACT FROM AUTHOR]

Almost three-quarters of a century ago, Ernst Mayr (1950) shocked paleoanthropologists into an exceptionalist taxonomic minimalism that lingers today. As a result, a constant stream of new fossil discoveries has been shoehorned wherever possible into existing taxa, almost irrespective of morphology. This compression has been especially true at the level of the genus, where virtually all except very early hominins have over the last couple of decades been classified and named according to the unconscious algorithm, "if it isn't Australopithecus , it is Homo " (and vice versa). This has led to a vastly overstuffed genus Homo , which has lost any phylogenetic or morphological coherence. Genera are monophyletic clusters of species; and although their boundaries in terms of species content are arbitrary, they do contain phylogenetic structure that ultimately needs to be expressed. Homininae is a large and diverse taxon; and this essay is a plea to paleoanthropologists not only to reflect the phylogenetic structure within it by employing an adequate number of generic and species names, but at the same time to acknowledge the internationally agreed rules (especially of priority) that govern the naming of zoological taxa. [ABSTRACT FROM AUTHOR]

Quercetin has been shown to possess beneficial pharmacological properties in treatment of heart disease, but lack of stability and bioavailability limits its clinical use. In this study, we investigated for the first time the effect of a methylated form of quercetin, 3,3′,4′,5,7-pentamethylquercetin (PMQ), on myocardial protection in rats. Angiotensin II was delivered to Sprague-Dawley rats subcutaneously, while PMQ (5 mg/kg) was administered by oral gavage; blood pressure was monitored daily. The production of NADPH oxidase was measured, and cardiac hypertrophy and apoptosis were detected. The results revealed that PMQ could downregulate the expression of the NADPH oxidase gene and reduce angiotensin II- induced cardiac hypertrophy and apoptosis in rats. Therefore, we believe that PMQ showed beneficial effects on myocardium in angiotensin II-administered rats, and its potential to be used for treatment of cardiovascular disease deserves further attention. [ABSTRACT FROM AUTHOR]

Abstract: In living plant collections, vegetatively propagated accessions are outstanding material with respect to vulnerability and labour amount. This is also true for the main vegetative material, held in the IPK, Gatersleben. A survey of the preservation of potato, garlic and other alliums, mint and yam is given. More than 630 accessions are in slow growth conditions. Amongst them, 99 clones of garlic and 35 of shallot have been tested to be virus-free. Cryopreservation is routinely applied for potato using the droplet method. The cryo-collection contains more than 1000 accessions, a part of which has been integrated from another collection, formerly established at Braunschweig. Cryopreservation of garlic has been used to store the accessions of the European core collection. Cryopreservation is successful in three Dioscorea species using a combination of the original vitrification with the droplet method. Investigations about morphogenesis and ultrastructural cell parameters before, during and after cryopreservation were included in these activities. [Copyright &y& Elsevier]