La Trobe University

About: La Trobe University is a education organization based out in Melbourne, Victoria, Australia. It is known for research contribution in the topics: Population & Health care. The organization has 13370 authors who have published 41291 publications receiving 1138269 citations. The organization is also known as: LaTrobe University & LTU.

Zircon and monazite response to prograde metamorphism in the Reynolds Range, central Australia

Abstract: We report an extensive field-based study of zircon and monazite in the metamorphic sequence of the Reynolds Range (central Australia), where greenschist- to granulite-facies metamorphism is recorded over a continuous crustal section. Detailed cathodoluminescence and back-scattered electron imaging, supported by SHRIMP U–Pb dating, has revealed the different behaviours of zircon and monazite during metamorphism. Monazite first recorded regional metamorphic ages (1576 ± 5 Ma), at amphibolite-facies grade, at ∼600 °C. Abundant monazite yielding similar ages (1557 ± 2 to 1585 ± 3 Ma) is found at granulite-facies conditions in both partial melt segregations and restites. New zircon growth occurred between 1562 ± 4 and 1587 ± 4 Ma, but, in contrast to monazite, is only recorded in granulite-facies rocks where melt was present (≥700 °C). New zircon appears to form at the expense of pre-existing detrital and inherited cores, which are partly resorbed. The amount of metamorphic growth in both accessory minerals increases with temperature and metamorphic grade. However, new zircon growth is influenced by rock composition and driven by partial melting, factors that appear to have little effect on the formation of metamorphic monazite. The growth of these accessory phases in response to metamorphism extends over the 30 Ma period of melt crystallisation (1557–1587 Ma) in a stable high geothermal regime. Rare earth element patterns of zircon overgrowths in leucosome and restite indicate that, during the protracted metamorphism, melt-restite equilibrium was reached. Even in the extreme conditions of long-lasting high temperature (750–800 °C) metamorphism, Pb inheritance is widely preserved in the detrital zircon cores. A trace of inheritance is found in monazite, indicating that the closure temperature of the U–Pb system in relatively large monazite crystals can exceed 750–800 °C.

Analysis of new and existing methods of reducing intercarrier interference due to carrier frequency offset in OFDM

Abstract: Orthogonal frequency division multiplexing (OFDM) is very sensitive to frequency errors caused by frequency differences between transmitter and receiver local oscillators. This sensitivity is analyzed in terms of the complex weighting coefficients which give the contribution of each transmitter subcarrier to each demodulated subcarrier. Previously described windowing and self intercarrier interference (ICI) cancellation methods are analyzed in terms of these weighting coefficients. New ICI cancellation schemes with very much improved performance are described. A condition for orthogonality of windowing schemes is derived in terms of the discrete Fourier transform (DFT) of the windowing function.

Reliability of Measurements Obtained With the Timed “Up & Go” Test in People With Parkinson Disease

Abstract: Background and Purpose. The Timed “Up & Go” Test (TUG) is used to measure the ability of patients to perform sequential locomotor tasks that incorporate walking and turning. This study investigated the retest reliability, interrater reliability, and sensitivity of TUG scores in detecting changes in mobility in subjects with idiopathic Parkinson disease (PD). Subjects. The performance of 12 people with PD was compared with that of 12 age-matched comparison subjects without PD. Methods. The subjects with PD completed 5 trials of the TUG after withdrawal of levodopa for 12 hours (“off” phase of the medication cycle) as well as an additional 5 trials 1 hour after levodopa was administered (“on” phase of the medication cycle). They were scored on the Modified Webster Scale at both sessions. The comparison subjects also performed 5 TUG trials. All trials were videotaped and timed by 2 experienced raters. The videotape was later rated by 3 experienced clinicians and 3 inexperienced clinicians. Results. For the subjects with PD, within-session performance was highly consistent, with correlations ( r ) ranging from .80 to .98 for the “off” phase and from .73 to .99 for the “on” phase. The performance of the comparison subjects across the 5 trials was also highly consistent ( r =.90–.97). Comparisons showed differences between trials 1 and 2 on the TUG for both groups. Removal of data for trial 1 (the practice trial) further enhanced retest reliability. There was close agreement in TUG scores among raters despite different levels of experience (intraclass correlation coefficient [3,1]=.87–.99). Mean TUG scores were different between the “on” and “off” phases of the levodopa cycle and between subjects with PD and comparison subjects during the “on” phase. Conclusion and Discussion. Retest reliability and interrater reliability of the TUG measurements were high, and the measurements reflected changes in performance according to levodopa use. The TUG can also be used to detect differences in performance between people with PD and elderly people without PD.

Rapid spread of an inherited incompatibility factor in California Drosophila.

Abstract: IN Drosophila simulans in California, an inherited cytoplasmic incompatibility factor reduces egg hatch when infected males mate with uninfected females1–7. The infection is spreading at a rate of more than 100km per year; populations in which the infection was rare have become almost completely infected within three years. Analyses of the spread using estimates of selection in the field suggest dispersal distances far higher than those found by direct observation of flies. Hence, occasional long-distance dispersal, possibly coupled with local extinction and recolonization, may be important to the dynamics. Incompatibility factors that can readily spread through natural populations may be useful for population manipulation and important as a post-mating isolating mechanism.