Internet Directory… 2002: International Year of ECOTOURISM

The following outlines internet resources useful to the practicing surveyor. It includes overview and internet linkages to International Year of Ecotourism (IYE); Eco-tourism in Australia and furthers the discussion with a brief overview of the Australian Year of the Outback

Entering the Real World

Priding itself on being a ‘University for the Real World', Queensland University of Technology (QUT) practises what it preaches. In a move to bring its surveying students in the School of Planning, Landscape Architecture & Surveying up to speed with the real-life work force environment, QUT has recently installed 30 licences of 4D Model

Book Review of "Longitude"

Book Review of "Longitude" A fascinating book about the solution of the "Longitude problem"

Students Benefit from GPS Deal

QUT students are now being trained in the latest technology following the acquisition of Geodetic surveying and mapping GPS hardware and software worth $125,000. After twelve months of negotiation between QUT surveying staff and US Satellite Navigation firm Trimble Navigation and their Brisbane agents, Herga Ultimate Positioning, the Global Positioning System equipment has been installed. Associate lecturer in the School of Planning, Landscape Architecture and Surveying Robert Webb said the leading edge GPS equipment could be worn like a back-pack and used in all weather conditions

DNA methylation associated with postpartum depressive symptoms overlaps findings from a genome-wide association meta-analysis of depression

Background Perinatal depressive symptoms have been linked to adverse maternal and infant health outcomes. The etiology associated with perinatal depressive psychopathology is poorly understood, but accumulating evidence suggests that understanding inter-individual differences in DNA methylation (DNAm) patterning may provide insight regarding the genomic regions salient to the risk liability of perinatal depressive psychopathology. Results Genome-wide DNAm was measured in maternal peripheral blood using the Infinium MethylationEPIC microarray. Ninety-two participants (46% African-American) had DNAm samples that passed all quality control metrics, and all participants were within 7 months of delivery. Linear models were constructed to identify differentially methylated sites and regions, and permutation testing was utilized to assess significance. Differentially methylated regions (DMRs) were defined as genomic regions of consistent DNAm change with at least two probes within 1 kb of each other. Maternal age, current smoking status, estimated cell-type proportions, ancestry-relevant principal components, days since delivery, and chip position served as covariates to adjust for technical and biological factors. Current postpartum depressive symptoms were measured using the Edinburgh Postnatal Depression Scale. Ninety-eight DMRs were significant (false discovery rate \u3c 5%) and overlapped 92 genes. Three of the regions overlap loci from the latest Psychiatric Genomics Consortium meta-analysis of depression. Conclusions Many of the genes identified in this analysis corroborate previous allelic, transcriptomic, and DNAm association results related to depressive phenotypes. Future work should integrate data from multi-omic platforms to understand the functional relevance of these DMRs and refine DNAm association results by limiting phenotypic heterogeneity and clarifying if DNAm differences relate to the timing of onset, severity, duration of perinatal mental health outcomes of the current pregnancy or to previous history of depressive psychopathology

Novel all-optical on-off-keyed to alternate-mark-inversion converter

We numerically investigate a novel 40 Gbps OOK to AMI all-optical modulation format converter employing an SOA-based Mach-Zehnder interferometer.  We demonstrate operation with a 27-1 PRBS and explain the phase modulation's relationship with patterning

All-optical technique for modulation format conversion from on-off-keying to alternate-mark-inversion

We propose and numerically investigate for the first time a novel all-optical on-off-keying to alternate-mark-inversion modulation format converter operating at 40 Gbps employing a semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI). Wedemonstrate that this SOA-MZI operates as a pulse subtractor, and in the absence of patterning will produce perfectly phase inverted pulses regardless of the individual SOA phase excursions. We use a comprehensive computer model to illustrate the impact of patterning on the output phase modulation which is quantified through the definition of the phase compression factor

Pattern compensation in SOA-based gates

We propose a novel scheme employing complementary data inputs to overcome the patterning normally associated with semiconductor optical amplifier based gates and demonstrate the scheme experimentally at 42.6Gb/s. The scheme not only avoids introducing patterning during switching, but also compensates for much of the patterning present on theinput data. A novel gate was developed for the experiment to provide the complementary signals required for the scheme