8,140 research outputs found
A new notospiriferine genus (Spiriferida: Brachiopoda) from the Permian of Tasmania
Farmerella exoporosa gen. et sp.nov. is described from cold-water Permian (Bernacchian-Lymingtonian) rocks of Tasmania. The new taxon is essentially homeomorphic with Glendonia McClung & Armstrong, 1978. However, Glendonia possesses a micro-ornament of low, elongate microspines behind shallow, elongate grooves, whereas Farmerella gen.nov. (as in Notospirifir Harrington, 195 5) has deep, elongate and globose pits which penetrate the rhickened outer primary shell layer but not the inner shell layer. This feature suggests that Notospirifir and Farmerell.a gen.nov. are closely related and should be assigned to a separate subfamily, the Notospiriferinae Archbold & Thomas, 1986 (emended herein), and Glendonia, BirchsellaClarke, 1987 and KelsoviaClarke, 1990 to a separate subfamily, the Glendoniinae nov. The areal and stratigraphical distributions, and evolutionary relationships of the various genera are briefly discussed
The stratigraphy of a Late Palaeozoic borehole section at Douglas River, eastern Tasmania: a synthesis of marine macro-invertebrate and palynological data
A section 236.8 m in thickness of Late Palaeozoic (Late Carboniferous-Permian) rocks of the Lower Parmeener Super-Group was encountered in a borehole at Douglas River, eastern Tasmania. Lithological, marine macro-invertebrate and palynological data are documented and collated. The section displays many similarities with sequences elsewhere in eastern and northeastern Tasmania, but is unusual in the development of rocks (including Tasmanites shale) as old as Early Tamarian. This occurrence may indicate a narrow, but significant east-west breaching of the land barrier which persisted throughout the Tamarian over most of eastern and northeastern Tasmania. Acritarch swarms coeval with
sedimentation occur at intervals, whereas other acritarchs may be derived from earlier Palaeozoic rocks. The Tasmanian Late Permian palynofloras lack diversity and resemble those from the Transantarctic Mountains, Antarctica, rather than those from elsewhere in eastern Australia
Parmeener supergroup (Lower Part) Poatina
In Tasmania, the lower (Permo-Carboniferous) rocks of
the Parmeener Supergroup are almost everywhere subhorizontal,
and rest with pronounced landscape unconformity on a folded
basement sequence, which is variously composed of Precambrian
and early Palaeozoic strata. In order to appreciate the late
Palaeozoic history of the Central Plateau district, it is
necessary to understand the nature of this unconformity
A Late Permian fossil horseshoe crab (Paleolimulus: Xiphosura) from Poatina, Great Western Tiers, Tasmania
The xiphosuran Paleolimulus Dunbar, 1923 is recorded from the Late Permian (Chhidruan) Jackey Shale at Poatina, 41°48'05"S 146°53'06"E. This is the first record of the genus in both Tasmania and the Southern Hemisphere, and extends its distribution to rocks deposited in a high latitude, cold-water environment
âMind the Gapâ . . . Establishing Measurement Capability in the Terahertz Gap Region â from 0.1 THz to 1.1 THz
This paper reviews the current state-of-the-art of measurements made using vector network analysers operating in the 0.1 THz to 1.1 THz frequency range. The paper concentrates on the development of three types of measurement capability: (i) in rectangular metallic waveguides; (ii) on-wafer planar circuits; (iii) bulk material characterisations. The paper describes progress to date with establishing this measurement capability and reviews the remaining challenges facing this measurement community
Structure and superconductivity of LiFeAs
The lithium ions in Lithium iron arsenide phases with compositions close to
LiFeAs have been located using powder neutron diffraction. These phases exhibit
superconductivity at temperatures at least as high as 16 K demonstrating that
superconductivity in compounds with [FeAs]- anti-PbO-type anionic layers occurs
in compounds with at least three different structure types and occurs for a
wide range of As-Fe-As bond angles.Comment: 3 pages, 3 figures, 3 table
Some solutions to the multivariate Behrens-Fisher problem for dissimilarity-based analyses
The essence of the generalised multivariate BehrensâFisher problem (BFP) is how to test the null hypothesis of equality of mean vectors for two or more populations when their dispersion matrices differ. Solutions to the BFP usually assume variables are multivariate normal and do not handle highâdimensional data. In ecology, species' count data are often highâdimensional, nonânormal and heterogeneous. Also, interest lies in analysing compositional dissimilarities among whole communities in nonâEuclidean (semiâmetric or nonâmetric) multivariate space. Hence, dissimilarityâbased tests by permutation (e.g., PERMANOVA, ANOSIM) are used to detect differences among groups of multivariate samples. Such tests are not robust, however, to heterogeneity of dispersions in the space of the chosen dissimilarity measure, most conspicuously for unbalanced designs. Here, we propose a modification to the PERMANOVA test statistic, coupled with either permutation or bootstrap resampling methods, as a solution to the BFP for dissimilarityâbased tests. Empirical simulations demonstrate that the type I error remains close to nominal significance levels under classical scenarios known to cause problems for the unâmodified test. Furthermore, the permutation approach is found to be more powerful than the (more conservative) bootstrap for detecting changes in community structure for real ecological datasets. The utility of the approach is shown through analysis of 809 species of benthic softâsediment invertebrates from 101 sites in five areas spanning 1960 km along the Norwegian continental shelf, based on the Jaccard dissimilarity measure
Effects of movement velocity and training frequency of resistance exercise on functional performance in older adults: a randomised controlled trial
Objectives: To investigate the effects that high-velocity, low-load (HVLL) and low-velocity, high-load (LVHL) resistance exercise, performed once or twice-weekly, have on indices of functional performance (primary outcome), maximal strength, and body composition (secondary outcomes) in older adults. Methods: In a randomised, controlled, multi-armed, parallel design, 54 moderately-highly active, but resistance exercise naĂŻve older adults (aged 60â79 years), attended baseline and post-10-week intervention assessment sessions. Physical and functional assessments were completed, and predicted one-repetition maximums (1-RM) were obtained for eight exercises. Participants were then randomised into one of five conditions: HVLL once-weekly (HVLL1: n = 11) or twice-weekly (HVLL2: n = 11), LVHL once-weekly (LVHL1: n = 10) or twice-weekly (LVHL2: n = 11), no-exercise control condition (CON: n = 11). The HVLL conditions completed 3 sets of 14 repetitions at 40% 1-RM and the LVHL conditions, 3 sets of 7 repetitions at 80% 1-RM. In total, 50 participants completed all testing and were included in analyses. Results: Only LVHL2 improved 30-sec chair stand performance (p =.035; g = 0.89), arm curls (p =.011; g = 1.65) and grip-strength (p =.015; g = 0.34) compared to CON. LVHL2 improved maximal strength compared to CON for 7/8 exercises (p <.05). Whereas, LVHL1 and HVLL2 only improved seated row and chest press compared to CON (p <.05). Conclusion: Possibly due to the lower intensity nature of the HVLL conditions, LVHL, twice-weekly was most beneficial for improving functional performance and strength in moderately-highly active older adults. Therefore, we recommend that exercise professionals ensure resistance exercise sessions have sufficient intensity of effort and volume, in order to maximise functional performance and strength gains in older adults.Â
Redox linked flavin sites in extracellular decaheme proteins involved in microbe-mineral electron transfer
Extracellular microbe-mineral electron transfer is a major driving force for the oxidation of organic carbon in many subsurface environments. Extracellular multi-heme cytochromes of the Shewenella genus play a major role in this process but the mechanism of electron exchange at the interface between cytochrome and acceptor is widely debated. The 1.8 Ă
x-ray crystal structure of the decaheme MtrC revealed a highly conserved CX8C disulfide that, when substituted for AX8A, severely compromised the ability of S. oneidensis to grow under aerobic conditions. Reductive cleavage of the disulfide in the presence of flavin mononucleotide (FMN) resulted in the reversible formation of a stable flavocytochrome. Similar results were also observed with other decaheme cytochromes, OmcA, MtrF and UndA. The data suggest that these decaheme cytochromes can transition between highly reactive flavocytochromes or less reactive cytochromes, and that this transition is controlled by a redox active disulfide that responds to the presence of oxygen
Status and subdivision of the Parmeener Super-group
Late Palaeozoic and Early Mesozoic rocks of the Parmeener Super-Group
are subdivided on a strict lithostratigraphical basis, and not in the time terms
'Permian' and 'Triassic'
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