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Aboriginal migration from South East Asia is the beginning of Australian economic history. Prehistorians have tended to focus on means to sea travel rather than opportunity and motive to migrate. American and Australian measures of sea depth contours throw new light on possible migration paths and the conditions that might have prompted Aboriginal ancestors to move through island SE Asia to Australia. Interpretation of the data depends on a reconsideration of palaeodemography and the introduction of some economic and historical analysis. Several scenarios suggest possible conditions influencing trends and fluctuations in Aboriginal migration over the past 60,000 years.
A consistent muscle activation strategy underlies crawling and swimming in Caenorhabditis elegans
(2014)
Although undulatory swimming is observed in many organisms, the neuromuscular basis for undulatory movement patterns is not well understood. To better understand the basis for the generation of these movement patterns, we studied muscle activity in the nematode Caenorhabditis elegans. Caenorhabditis elegans exhibits a range of locomotion patterns: in low viscosity fluids the undulation has a wavelength longer than the body and propagates rapidly, while in high viscosity fluids or on agar media the undulatory waves are shorter and slower. Theoretical treatment of observed behaviour has suggested a large change in force–posture relationships at different viscosities, but analysis of bend propagation suggests that short-range proprioceptive feedback is used to control and generate body bends. How muscles could be activated in a way consistent with both these results is unclear. We therefore combined automated worm tracking with calcium imaging to determine muscle activation strategy in a variety of external substrates. Remarkably, we observed that across locomotion patterns spanning a threefold change in wavelength, peak muscle activation occurs approximately 45° (1/8th of a cycle) ahead of peak midline curvature. Although the location of peak force is predicted to vary widely, the activation pattern is consistent with required force in a model incorporating putative length- and velocity-dependence of muscle strength. Furthermore, a linear combination of local curvature and velocity can match the pattern of activation. This suggests that proprioception can enable the worm to swim effectively while working within the limitations of muscle biomechanics and neural control.
The Peak Range (22˚ 28’ S; 147˚ 53’ E) is an archipelago of rocky peaks set in grassy basalt rolling-plains, east of Clermont in central Queensland. This report describes the flora and vegetation based on surveys of 26 peaks. The survey recorded all plant species encountered on traverses of distinct habitat zones, which included the ‘matrix’ adjacent to each peak. The method involved effort comparable to a general flora survey but provided sufficient information to also describe floristic association among peaks, broad habitat types, and contrast vegetation on the peaks with the surrounding landscape matrix. The flora of the Peak Range includes at least 507 native vascular plant species, representing 84 plant families. Exotic species are relatively few, with 36 species recorded, but can be quite prominent in some situations. The most abundant exotic plants are the grass Melinis repens and the forb Bidens bipinnata. Plant distribution patterns among peaks suggest three primary groups related to position within the range and geology. The Peak Range makes a substantial contribution to the botanical diversity of its region and harbours several endemic plants among a flora clearly distinct from that of the surrounding terrain. The distinctiveness of the range’s flora is due to two habitat components: dry rainforest patches reliant upon fire protection afforded by cliffs and scree, and; rocky summits and hillsides supporting xeric shrublands. Plants endemic to the Peak Range are mainly associated with the latter of these habitats.
Twenty-eight species of epiphyllous liverworts were identified from twenty-five sites in Kowloon Peninsula, Hong Kong. Twenty-four of these species are new records to Hong Kong, while four of them are new epiphyllous records to the Chinese mainland. The majority of the sites are located between 30-200 m above sea level, representing the lowest altitude of epiphyllous liverworts found in the Chinese mainland. Characteristics of the host plants bearing epiphyllous liverworts are briefly discussed. The following new combination is proposed: Cololejeunea pseudolatilobula (Chen & Wu) But & Gao comb. nov. (Pedinolejeunea pseudolatilobula Chen & Wu).
Four species of Ardisia (Myrsinaceae, Magnoliopsida) with rosette or low-lying leaves in China (including Hong Kong) have been found to be the hosts for 12 species of epiphyllous liverworts which belong to 4 families and 9 genera. However, no obvious species-specific hostepiphyte relationship could be recognized.
Scholars are coming to terms with the fact that something is rotten in the new democracies of Central Europe. The corrosion has multiple symptoms: declining trust in democratic institutions, emboldened uncivil society, the rise of oligarchs and populists as political leaders, assaults on an independent judiciary, the colonization of public administration by political proxies, increased political control over media, civic apathy, nationalistic contestation and Russian meddling. These processes signal that the liberal-democratic project in the so-called Visegrad Four (the Czech Republic, Hungary, Poland and Slovakia) has been either stalled, diverted or reversed. This article investigates the “illiberal turn” in the Visegrad Four (V4) countries. It develops an analytical distinction between illiberal “turns” and “swerves”, with the former representing more permanent political changes, and offers evidence that Hungary is the only country in the V4 at the brink of a decisive illiberal turn.
Wirkung von Glia-Maturationsfaktor (GMF) und Adhäsionsfaktor (ADF) auf Kulturen leukämischer Zellen
(1987)
GMF was isolated from the glia of different brain parts of calf. Its influence on the input of 3H-TdR was tested in leukaemic and non-malignant lymphocites. GMF isolated from the diencephalon proved to be the most effective one. The used substance of reference was DBcAMP. The cAMP contents of leukaemic cells were lower than those of non-malignant cells, whereas the level of cGMP was higher in the first ones. We found both in non-malignant cultures and in cultures of leukaemic cells that the impact of GMF and AdF elevated the cAMP value and reduced cGMP. The adhesion of cAMP to the nuclei of leukaemic was reduced in comparison with non-malignant cells. The nuclei of leukaemic cells showed increased adhesive capacity after pre-incubation with GMF and AdF. The adhesive capacity of non-malignant nuclei remained unchanged. The adenylcyclase activity (AC) was diminished in leukaemic cells. It could not be stimulated by means of catecholamines. GMF and AdF produced a slight increase of the basal Ac activity in cultures of leukaemic cells only. But isoproterenol led to a distinct increase of the Ac activity in leukaemic cells when incubation with those two factors preceded it.
Visible light is a better co-inducer of apoptosis for curcumin-treated human melanoma cells than UVA
(2013)
Curcumin attracts worldwide scientific interest due to its anti-proliferative and apoptosis inducing effects on different tumor cells at concentrations ranging from 10 to 150 µM (3.7–55 µg/ml). Unfortunately, because of a low oral bioavailability, only low and pharmacologically ineffective serum levels are achievable. In this study, an alternative treatment concept consisting of low concentration curcumin (0.2–5 µg/ml) and irradiation with UVA or visible light (VL) has been tested. The experimental results show clearly that this treatment decreases the proliferation and the viability of human melanoma cells while the cell membrane integrity remains intact. We identified the onset of apoptosis characterized by typical markers such as active caspases 8, 9 and 3 as well as DNA fragmentation accompanied by the loss of cell adhesion. The mitochondrial apoptosis signaling pathway is predominant due to an early activation of caspase-9. The present data indicate a higher efficacy of a combination of curcumin and VL than curcumin and UVA. Reduced effects as a result of light absorption by heavily pigmented skin are unlikely if VL is used. These results indicate that a combination of curcumin and light irradiation may be a useful additional therapy in the treatment of malignant disease.