Determination of vertical hydraulic conductivity of aquitards in a multilayered leaky system using water-level signals in adjacent aquifers

This paper presents a methodology for determining the vertical hydraulic conductivity (Kv) of an aquitard, in a multilayered leaky system, based on the harmonic analysis of arbitrary water-level fluctuations in aquifers. As a result, Kv of the aquitard is expressed as a function of the phase-shift of water-level signals measured in the two adjacent aquifers. Based on this expression, we propose a robust method to calculate Kv by employing linear regression analysis of logarithm transformed frequencies and phases. The frequencies, where the Kv are calculated, are identified by coherence analysis. The proposed methods are validated by a synthetic case study and are then applied to the Westbourne and Birkhead aquitards, which form part of a five-layered leaky system in the Eromanga Basin, Australia.

Variation in leaf structure of the invasive Madeira vine (Anredera cordifolia, Basellaceae) at different light levels

Madeira vine (Anredera cordifolia (Ten.) Steenis) is a climber in the angiosperm family Basellaceae. It is native to South America and has naturalised in Australia. It is regarded as a serious environmental weed because of the structural damage it causes to native vegetation. The present study, for the first time, documents anatomical and morphological traits of the leaves of A. cordifolia and considers their implications for its ecology and physiology. Plants were grown under three different light levels, and anatomical and morphological leaf characters were compared among light levels, among cohorts, and with documented traits of the related species, Basella alba L. Stomata were present on both the adaxial and abaxial sides of the leaf, with significantly more stomata on the abaxial side and under high light. This may account for the ability of this species to fix large amounts of carbon and rapidly respond to light gaps. The leaves had very narrow veins and no sclerenchyma, suggesting a low construction cost that is associated with invasive plants. There was no significant difference in any of the traits among different cohorts, which agrees with the claim that A. cordifolia primarily propagates vegetatively. The anatomy and morphology of A. cordifolia was similar to that of B. alba.

Plant structure and systematics research at the Queensland University of Technology (QUT), Brisbane

This article provides a general overview of some of the plant research being conducted by a number of researchers at the Queensland University of Technology (QUT) Brisbane. Details about student projects and research facilities have been limited to those of relevance to plant structure and systematics. Academics, technicians and research students involved in plant research are in the Faculty of Science and Engineering, mainly in the School of Earth, Environment and Biological Sciences (EEBS), with a few exceptions. Our offices and laboratories are housed in a number of different buildings at the Gardens Point campus (e.g., P, Q, R, S, M Blocks) and we have strong collaborative links with Queensland Herbarium (BRI) and Mt Coot-tha Botanic Gardens.

Assessment of the molecular structure of natrodufrénite – NaFe2+Fe3+5(PO4)4(OH)6•2(H2O), a secondary pegmatite phosphate mineral from Minas Gerais, Brazil

The mineral natrodufrénite a secondary pegmatite phosphate mineral from Minas Gerais, Brazil, has been studied by a combination of scanning electron microscopy and vibrational spectroscopic techniques. Electron probe analysis shows the formula of the studied mineral as (Na0.88Ca0.12)∑1.00(Mn0.11Mg0.08Ca0.04Zr0.01Cu0.01)∑0.97(Al0.02)∑4.91(PO4)3.96(OH6.15F0.07)6.22⋅2.05(H2O). Raman spectroscopy identifies an intense peak at 1003 cm−1 assigned to the ν1 symmetric stretching mode. Raman bands are observed at 1059 and 1118 cm−1 and are attributed to the ν3 antisymmetric stretching vibrations. A comparison is made with the spectral data of other hydrate hydroxy phosphate minerals including cyrilovite and wardite. Raman bands at 560, 582, 619 and 668 cm−1 are assigned to the ν4 bending modes and Raman bands at 425, 444, 477 and 507 cm−1 are due to the ν2 bending modes. Raman bands in the 2600–3800 cm−1 spectral range are attributed to water and OH stretching vibrations. Vibrational spectroscopy enables aspects of the molecular structure of natrodufrénite to be assessed.

Population structure and patterns of genetic variation in a pearl oyster (Pinctada radiata) native to the Arabian Gulf

The study assessed natural levels and patterns of genetic variation in Arabian Gulf populations of a native pearl oyster to define wild population structure considering potential intrinsic and extrinsic factors that could influence any wild structure detected. The study was also the first attempt to develop microsatellite markers and to generate a genome survey sequence (GSS) dataset for the target species using next generation sequencing technology. The partial genome dataset generated has potential biotechnological applications and for pearl oyster farming in the future.

The Chinese state enterprise sector: Labour market reform and the impact on male–female wage structure

The paper examines the wage structure in the Chinese state enterprise sector between 1981 and 1987. This period is of particular interest given the introduction of major labour market reforms in China during the early 1980s. In essence the reforms represented a movement away from administratively determined prices towards a market–oriented system combined with a relatively flexible system of labour allocation. The Juhn, Murphy and Pierce (1991) decomposition is employed to shed light on the role of changing labour market institutions over the period.

Laboratory measurement of hydraulic conductivity functions of two unsaturated sandy soils during drying and wetting processes

The importance of applying unsaturated soil mechanics to geotechnical engineering design has been well understood. However, the consumption of time and the necessity for a specific laboratory testing apparatus when measuring unsaturated soil properties have limited the application of unsaturated soil mechanics theories in practice. Although methods for predicting unsaturated soil properties have been developed, the verification of these methods for a wide range of soil types is required in order to increase the confidence of practicing engineers in using these methods. In this study, a new permeameter was developed to measure the hydraulic conductivity of unsaturated soils using the steady-state method and directly measured suction (negative pore-water pressure) values. The apparatus is instrumented with two tensiometers for the direct measurement of suction during the tests. The apparatus can be used to obtain the hydraulic conductivity function of sandy soil over a low suction range (0-10 kPa). Firstly, the repeatability of the unsaturated hydraulic conductivity measurement, using the new permeameter, was verified by conducting tests on two identical sandy soil specimens and obtaining similar results. The hydraulic conductivity functions of the two sandy soils were then measured during the drying and wetting processes of the soils. A significant hysteresis was observed when the hydraulic conductivity was plotted against the suction. However, the hysteresis effects were not apparent when the conductivity was plotted against the volumetric water content. Furthermore, the measured unsaturated hydraulic conductivity functions were compared with predictions using three different predictive methods that are widely incorporated into numerical software. The results suggest that these predictive methods are capable of capturing the measured behavior with reasonable agreement.

Vibrational spectroscopic characterization of the phosphate mineral barbosalite Fe2+Fe3+2(PO4)2(OH)2 : implications for the molecular structure

Natural single-crystal specimens of barbosalite from Brazil, with general formula Fe2+Fe3+ 2 (PO4)2(OH)2 were investigated by Raman and infrared spectroscopy. The mineral occurs as secondary products in granitic pegmatites. The Raman spectrum of barbosalite is characterized by bands at 1020, 1033 and 1044 cm−1 cm−1, assigned to ν1 symmetric stretching mode of the HOPO3- 3 and PO3- 4 units. Raman bands at around 1067, 1083 and 1138 cm−1 are attributed to both the HOP and PO antisymmetric stretching vibrations. The set of Raman bands observed at 575, 589 and 606 cm−1 are assigned to the ν4 out of plane bending modes of the PO4 and H2PO4 units. Raman bands at 439, 461, 475 and 503 cm−1 are attributed to the ν2 PO4 and H2PO4 bending modes. Strong Raman bands observed at 312, 346 cm−1 with shoulder bands at 361, 381 and 398 cm−1 are assigned to FeO stretching vibrations. No bands which are attributable to water vibrations were found. Vibrational spectroscopy enables aspects of the molecular structure of barbosalite to be assessed.

The molecular structure of the borate mineral inderite Mg(H4B3O7)(OH)⋅5H2O – A vibrational spectroscopic study

We have undertaken a study of the mineral inderite Mg(H4B3O7)(OH)⋅5H2O a hydrated hydroxy borate mineral of magnesium using scanning electron microscopy, thermogravimetry and vibrational spectroscopic techniques. The structure consists of [B3O3(OH)5]2-[B3O3(OH)5]2- soroborate groups and Mg(OH)2(H2O)4 octahedra interconnected into discrete molecules by the sharing of two OH groups. Thermogravimetry shows a mass loss of 47.2% at 137.5 °C, proving the mineral is thermally unstable. Raman bands at 954, 1047 and 1116 cm−1 are assigned to the trigonal symmetric stretching mode. The two bands at 880 and 916 cm−1 are attributed to the symmetric stretching mode of the tetrahedral boron. Both the Raman and infrared spectra of inderite show complexity. Raman bands are observed at 3052, 3233, 3330, 3392 attributed to water stretching vibrations and 3459 cm−1 with sharper bands at 3459, 3530 and 3562 cm−1 assigned to OH stretching vibrations. Vibrational spectroscopy is used to assess the molecular structure of inderite.

Confirmation of the assignment of vibrations of goethite: An ATR and IES study of goethite structure

Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM/EDS) and X-ray diffraction (XRD) were used to characterize the morphology of synthetic goethite. The behavior of the hydroxyl/water molecular units of goethite and its thermally treated products were characterized using Fourier transform-infrared emission spectroscopy (FT-IES) and attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy. The results showed that all the expected vibrational bands between 4000 and 650 cm−1 including the resolved bands (3800–2200 cm−1) were confirmed. A band attributed to a new type of hydroxyl unit was found at 3708 cm−1 and assigned to the FeO–H stretching vibration without hydrogen bonding. This hydroxyl unit was retained up to the thermal treatment temperature of 500 °C. On the whole, seven kinds of hydroxyl units, involving three surface hydroxyls, a bulk hydroxyl, a FeO–H without hydrogen bonding, a nonstoichiometric hydroxyl and a reversed hydroxyl were observed, and three kinds of adsorbed water were found in/on goethite.

Role of hydraulic factors in constructed wetland and bioretention basin treatment performance

This research project contributed to the in-depth understanding of the influence of hydrologic and hydraulic factors on the stormwater treatment performance of constructed wetlands and bioretention basins in the "real world". The project was based on the comprehensive monitoring of a Water Sensitive Urban Design treatment train in the field and underpinned by complex multivariate statistical analysis. The project outcomes revealed that the reduction in pollutant concentrations were consistent in the constructed wetland, but was highly variable in the bioretention basin to a range of influential factors. However, due to the significant amount retention within the filter media, all pollutant loadings were reduced in the bioretention basin.

Aligned poly(L-lactic-co-ε-caprolactone) electrospun microfibers and knitted structure: a novel composite scaffold for ligament tissue engineering

We developed a novel technique involving knitting and electrospinning to fabricate a composite scaffold for ligament tissue engineering. Knitted structures were coated with poly(L-lactic-co-e-caprolactone) (PLCL) and then placed onto a rotating cylinder and a PLCL solution was electrospun onto the structure. Highly aligned 2-μm-diameter microfibers covered the space between the stitches and adhered to the knitted scaffolds. The stress–strain tensile curves exhibited an initial toe region similar to the tensile behavior of ligaments. Composite scaffolds had an elastic modulus (150 ± 14 MPa) similar to the modulus of human ligaments. Biological evaluation showed that cells proliferated on the composite scaffolds and they spontaneously orientated along the direction of microfiber alignment. The microfiber architecture also induced a high level of extracellular matrix secretion, which was characterized by immunostaining. We found that cells produced collagen type I and type III, two main components found in ligaments. After 14 days of culture, collagen type III started to form a fibrous network. We fabricated a composite scaffold having the mechanical properties of the knitted structure and the morphological properties of the aligned microfibers. It is difficult to seed a highly macroporous structure with cells, however the technique we developed enabled an easy cell seeding due to presence of the microfiber layer. Therefore, these scaffolds presented attractive properties for a future use in bioreactors for ligament tissue engineering.

Fluid-structure interaction analysis of full scale vehicle-barrier impact using coupled SPH-FEA

Portable water-filled barriers (PWFB) are roadside structures used to separate moving traffic from work-zones. Numerical PWFB modelling is preferred in the design stages prior to actual testing. This paper aims to study the fluid-structure interaction of PWFB under vehicular impact using several methods. The strategy to treat water as non-structural mass was proposed and the errors were investigated. It was found that water can be treated with the FEA-NSM model for velocities higher than 80kmh-1. However, full SPH/FEA model is still the best treatment for water and necessary for lower impact velocities. The findings in this paper can be used as guidelines for modelling and designing PWFB.

Validation of a new tool to measure responsiveness and structure in the feeding context : the Authoritative Feeding Practices Questionnaire

How mothers interact with their toddlers around food lays the foundations for healthy eating and healthy weight gain in later life. This research involving 467 Australian first-time mothers of 2-year-old children resulted in the development of a new self-report tool, the Authoritative Feeding Practices Questionnaire, assessing maternal responsive feeding and mealtime structure. Secondary analysis of the NOURISH randomised controlled trial included theory-driven item selection, confirmatory factor analysis, evaluation of psychometric properties and construct validation. The result is a brief, reliable and valid new tool for evaluating the maternal feeding practices that support children to become healthy, independent eaters.

The structure of Pavlovian fear conditioning in the amygdala

Do different brains forming a specific memory allocate the same groups of neurons to encode it? One way to test this question is to map neurons encoding the same memory and quantitatively compare their locations across individual brains. In a previous study, we used this strategy to uncover a common topography of neurons in the dorsolateral amygdala (LAd) that expressed a learning-induced and plasticity-related kinase (p42/44 mitogen-activated protein kinase; pMAPK), following auditory Pavlovian fear conditioning. In this series of experiments, we extend our initial findings to ask to what extent this functional topography depends upon intrinsic neuronal structure. We first showed that the majority (87 %) of pMAPK expression in the lateral amygdala was restricted to principal-type neurons. Next, we verified a neuroanatomical reference point for amygdala alignment using in vivo magnetic resonance imaging and in vitro morphometrics. We then determined that the topography of neurons encoding auditory fear conditioning was not exclusively governed by principal neuron cytoarchitecture. These data suggest that functional patterning of neurons undergoing plasticity in the amygdala following Pavlovian fear conditioning is specific to memory formation itself. Further, the spatial allocation of activated neurons in the LAd was specific to cued (auditory), but not contextual, fear conditioning. Spatial analyses conducted at another coronal plane revealed another spatial map unique to fear conditioning, providing additional evidence that the functional topography of fear memory storing cells in the LAd is non-random and stable. Overall, these data provide evidence for a spatial organizing principle governing the functional allocation of fear memory in the amygdala.