20000 research outputs found
Sort by
The impact of prematurity on postnatal growth of different renal compartments
No full textAim: In humans, nephrogenesis ceases before birth, but the renal medulla compartment continues to develop after birth. We aim to evaluate the relative growth of different renal compartments in preterm babies compared with age‐matched term babies, and explore the impact of premature birth on postnatal renal maturation, remodelling and possible long‐term implications. Methods: This retrospective study compared the renal ultrasonographic images between preterm babies and term infants. Ultrasound images were obtained at 32 weeks (preterm), 37 weeks and at 6 months of age. Kidney volume, length, renal cortex and medulla thickness were measured and compared between preterm and term babies. Results: Preterm babies were lighter in body weight and shorter for crown‐heel length at age‐matched 37 weeks. All kidney growth parameters were also smaller compared with term babies. However, by 6 months of age kidney volume and length measurements were no longer significantly different between the two groups though preterm babies were still significantly lighter and shorter. The catch‐up of the overall kidney growth in preterm babies was mainly attributed to the hypertrophic growth of the renal cortex while the postnatal renal medulla growth was disrupted. This trend continued as the renal cortical thickness became significantly larger while the medulla became smaller in preterm babies at 6 months of age, compared with age‐matched term baby. Conclusions: In preterm babies, the renal cortical region undergoes accelerated growth after birth while the renal medulla growth lags behind. Further investigations will be necessary to determine whether this has a negative impact on renal function later in life
Identification, characterisation and modelling of dynamic adhesion for optimised transfer system design
No full textThe depletion of favourable bulk material deposits in relation to their handleability is prompting the industry to consider mining material that may have comparatively less favourable flow properties. Typically found beneath the water-table, less favourable bulk materials frequently exhibit an increased clay and moisture content, leading to Wet and Sticky Material (WSM) and problematic behaviours regarding handleability. WSMs can have a significant impact in the materials handling stream due to the expensive downtime of processing equipment, which is attributed to the complex inter-particle and boundary adhesion mechanisms found within the bulk material. To better understand the characteristics of WSMs, new theoretical models are required and consequently developed within the scope of this research. For the identification of a WSM, a comprehensive study was undertaken where revised testing methods have been developed to attain quantifiable measurements for the problematic characteristics of bulk materials. The wall adhesion and inter-particle adhesion tests were developed and adapted for iron ore from existing methods that are typically used for fine powders. These tests have been performed in conjunction with a sweep of traditional flow property tests which were conducted on three iron ore samples. The three iron ore samples have been supplied from the Pilbara region of Western Australia and include; Upper Channel Iron Deposit (UCID), Lower Channel Iron Deposit (LCID) and the Denatured Zone (found between the UCID and LCID layers). The threshold moisture content for problematic behaviours were identified, where, Denatured was identified as the most problematic in relation to the adhesive strength it exhibits. To further understand the adhesive properties of the iron ore samples, a revised methodology for the estimation of bulk material adhesion determined from the extrapolation of the Instantaneous Yield Locus (IYL) produced from Jenike direct shear testing was undertaken. The predicted adhesion values from this methodology are compared to experimental measurements using an inter-particle adhesion tester where good correlation was found. Once the adhesive properties of each iron ore sample were identified, a theoretical model was developed and validated experimentally to define the dynamic adhesion of the bulk material samples. The developed model was able to predict the geometrical constraints where the identification of the effective angle at which the shear failure equates to a zero-bond depth was found for three typical wall liners used in industry. Following the identification of the dynamic adhesion geometrical constraints, it was observed by the author that the natural agglomeration of the iron ore samples assisted in the flow of the material through transfer systems. Additionally, it was also observed that the formed agglomerates reduced the amount of dust generated during transportation. An investigation was undertaken on the effects of agglomeration on the materials handling sector where the benefits of reduced build-up and a reduction of dust generation was shown. It was found that for an equivalent Run-of-Mine (ROM) iron ore moisture content, there was a significant reduction for the amount of build-up that commonly leads to potential blockages in industry. The final aspect of the presented research is the utilisation of numerical simulations for the prediction of problematic behaviours found in industrial systems. The characteristics of WSMs can be computationally expensive to model and with the development of the Discrete Element Method (DEM) in conjunction with the advancement in computational power over the past decade, it is now more feasible to model WSMs in DEM simulations. Three cohesion models capable of replicating WSMs are investigated where the potential to replicate problematic bulk material behaviours and computational solve times are analysed. The models used include; the Simplified Johnson-Kendall-Roberts (SJKR) model, Easo Liquid Bridging model and the Edinburgh Elasto-Plastic Adhesion (EEPA) model. In this study, the coupling of the SJKR and Easo Liquid Bridging models is proposed and used to predict problematic bulk material behaviour. Additionally, a calibration procedure is developed and undertaken where the parameters for each cohesion model are discussed in detail. A series of calibration simulations with systematic parameter variation was undertaken to define a set of calibration matrices. The developed calibration matrices resulted in the selection of a unique parameter setting, which can be used for the simulation of on-site applications to optimise plant geometry and other operational parameters. Finally, numerical modelling validation was undertaken using a lab scale vertical impact testing facility where good correlation between experimental and simulation results was found
Rewards, perils and pitfalls of untangling spinal pain circuits
No full textPain is a complex perception that is fundamental to our daily survival. Under normal circumstances, it serves an important protective function to guard against tissue damage or alert the body to dangerous environments. Under pathological states, however, the perception of pain can become chronic, maladaptive, resistant to treatment, and presents a serious clinical and societal problem. A wealth of literature suggests that disruption of sensory processing within the spinal cord contributes to chronic pain, but our limited understanding of spinal circuitry in health and disease remains a barrier to the development of new therapeutic strategies. The aim of this brief review is to outline current thinking about how individual components of functionally distinct spinal microcircuits can be identified and manipulated to determine their role in influencing our perception of pain in acute and chronic states
An important, but neglected aspect of learning assistance in higher education: exploring the digital learning capacity of academic language and learning practitioners
No full textDigital literacy has become increasingly significant in tertiary environments, as institutions move towards preparing students for 21st century workplaces and careers that emphasise digital literacy. As such, Academic Language and Learning (ALL) practitioners within these institutions are under pressure to possess familiarity and skills in the digital education space. Despite this need, there is a shortage of evidence that identifies the competencies or gaps in the current knowledge that ALL advisors have in Australian tertiary institutions; there is also a lack of awareness about how to address the gaps in knowledge for technology-enhanced learning and academic support. In light of this lacuna, in late 2018, the Association for Academic Learning and Language (AALL), the professional body for Academic Language and Learning practitioners, established a working group to investigate the knowledge and gaps in digital literacy in the ALL profession. The authors of this paper are all members of this working group and aim to explore the state of digital learning in their field. The long-term aim of the working party is to develop research-led resources and strategies to assist in the professionalisation and upskilling of ALL staff in technology-enhanced academic language development and support. This paper reports on the preliminary findings of a mixed-method participatory action research study of ALL practitioners' preferences, competencies and confidence in the digital learning space. It is hoped that this study will provide members within the AALL professional body, as well as tertiary educators generally, with strategies required to identify, develop and maintain effective digital literacies across the higher education sector
An integrative review of acupressure interventions for older people: a focus on sleep quality, depression, anxiety, and agitation
No full textObjectives: This integrative review aimed to synthesize studies that investigated the effects of acupressure on sleep quality, depression, anxiety, and agitation in older people, and to describe the acupressure procedures and techniques applied in the included studies. Methods: A literature search was conducted using electronic databases including CINAHL, Cochrane Library, EMBASE, and MEDLINE. The inclusion criteria for the review were studies examining the effect of acupressure in older people aged 60 years and above, measured the outcomes for sleep quality, depression, anxiety or agitation, applied body acupressure, and published in English language. The exclusion criteria were studies using auricular acupoints only, and articles published in any language other than English. Methodological quality of studies was assessed using the critical appraised tools developed by the Joanna Briggs Institute. The information about study design, findings, and description of acupressure intervention were extracted, summarized, and synthesized. Results: A total of 255 articles were identified from the search and as well one article from cross-references. From there, a total of 19 studies were included in this review. Nine studies consistently showed positive effects of acupressure on sleep quality, and four studies consistently showed that acupressure reduced depression. The outcomes of acupressure on anxiety and agitation showed inconsistent findings, in which three studies measured anxiety and five studies measured agitation. There was also variation of acupressure techniques applied in the reviewed studies. Conclusion: This review found some emerging evidences that acupressure can be beneficial for older people who suffer from sleep problems and depression. Use of specific acupressure points, with standardized acupressure treatment protocols, may improve sleep quality and possibly psychological wellbeing of older people. Future research with well-designed mixed method studies are required to produce stronger evidence, as well as in-depth understanding of acupressure intervention in aged care context
Dynamic music: the implications of interactive technologies on popular music making
No full textThe thesis investigates the role of interactive technologies on popular music making. Popular music has always adapted to new technologies, however interactive technologies challenge the accepted forms of popular music making. The thesis introduces two interconnected problems for musicians wanting to embrace changes in technology and communication: the relationship between static (fixed) song forms in popular music and dynamic (fluid and adaptable) forms; and, the need for a set of criteria that can encompass the relationship between static and dynamic song forms. The research asks how can interactive technologies be used to develop new forms of popular music? A review of important musical works utilising interactive technologies and relevant literature is examined. With a foundation in game audio, computer music and interactive art approaches, the review identifies the emergence of a new field, Dynamic Music. Dynamic Music is music that can change and adapt to data. In order to create an experience beyond a static form, the music needs to provide many different playback options. Composing and producing Dynamic Music forms uses very different approaches compared to static music making. It consists of four components; a control system, music and sound content, musical architecture, and experience. Informed by practice-based research and research-led practice, the methodology develops a grounded theory approach in which an aesthetic of Dynamic Music is introduced. The methodology is underpinned by criteria based on the concepts of 'variability' and 'transmutability'. These criteria are directly related to the compositional model presented for Dynamic Music and provide a foundation for evaluating approaches in Dynamic Music making. The criteria provide a clear distinction between Dynamic Music and static music forms. A portfolio of creative works is provided as evidence of the methodological framework for Dynamic Music composition. The thesis concludes with an argument for the 'Dynamic Music Producer'. This is a new emerging role able to produce new disruptive music forms; develop systems for their playback and performance; and realise immersive music products and performances into the future
Analysis of time-variable gravity signal from GRACE data
No full textThe Gravity Recovery and Climate Experiment (GRACE) satellite mission revolutionized our understanding of mass redistribution in the Earth system from 2002 to 2017 by measuring time-variable gravity field with unprecedented accuracy. The conventional data products of GRACE are global monthly-mean snapshots of Level-2 (L2) time-variable gravity, and Level-3 or mascon surface mass change. The global monthly fields are obtained from the fundamental measurements of inter-satellite ranging acquired by the K-band ranging (KBR) system. Relying exclusively on the monthly data confines the application of GRACE to geophysical processes that are mainly characterized by seasonal and inter-annual variations such as terrestrial water, ice and ocean mass change. The primary aim of this thesis is to show that direct analysis of inter-satellite ranging data opens the way for detecting new geophysical mass changes at time-scales of significantly less than one month, such as tsunamis. By pushing the limit of GRACE, this thesis brings new opportunities to study new areas of the Earth system mass change. To study the gravitational effect of regional mass changes using GRACE, we first develop a transfer function based on correlation-admittance spectral analysis for accurate estimation of line-of-sight gravity difference (LGD) from inter-satellite range-acceleration. The correlation spectrum between LGD and range-acceleration shows near-unity correlation for frequencies above 1 mHz or 5 cycles-per-revolution (CPR), and the admittance spectrum quantifies the LGD response to range-acceleration at the correlated frequency band. As the first application, we employ the GRACE LGD observations to quantify surface water storage change and calibrate the stream flow velocity of runoff routing models in large river basins. Our results show that the optimal stream flow velocity for the Amazon and Siberian basins is ~0.3 m/s, while surface water in the Congo and Parana basins is better simulated with a velocity larger than 2.0 m/s. Consequently, surface water change explains as much as half of total water storage anomaly in the Amazon, while its contribution in Congo and Parana basins is almost negligible at the monthly temporal resolution [Ghobadi-Far et al., 2018, JGR Solid Earth]. Secondly, we examine the gravitational effect of tsunami-induced transient ocean mass change at 500 km altitude and its observation using GRACE. By upward continuing the gravitational effect of tsunami wave field to satellite altitude and comparison with GRACE LGD, we show that GRACE satellites have detected the tsunamis triggered by the great 2004 Sumatra, 2010 Maule, and 2011 Tohoku earthquakes. GRACE provides an independent source of information useful to discriminate among various seismic source models. This study in particular points to the potential of GRACE Follow-On to deliver low-latency gravimetric data for monitoring transient mass change due to extreme events such as tsunamis and hurricanes [Ghobadi-Far et al., 2019, under review, J. Geodesy]. Regional-scale co- and post-seismic gravity changes caused by great earthquakes are now routinely observed by GRACE L2 time-variable gravity data. Earthquakes also excite global-scale transient gravity changes at certain frequencies associated with Earth’s free oscillations which could last up to several days. In this study, we examine the global transient gravity changes excited by Earth’s free oscillations using the GRACE inter-satellite ranging data. By extending the Kaula orbit perturbation theory, we show that excited frequencies in GRACE KBR data are described by a linear combination of eigenfrequencies of the normal modes, Earth’s rotation rate, and satellite angular velocity. Wavelet analysis of the actual KBR residuals in December 2004 reveals the existence of a significant transient signal after the 2004 Sumatra earthquake with a frequency of ~0.022 mHz, which could be potentially related to the largest excitation due to the “football” mode. However, GRACE accelerometer noise seems to affect the reliability of the obtained results [Ghobadi-Far et al., 2019, JGR Solid Earth]. As the final contribution in this thesis, we put forward a rigorous theory for determining improved surface mass change from GRACE L2 data. The L2 time-variable gravity data are conventionally converted into surface mass change on the spherical Earth. Considering the accuracy of the current L2 data, we show that such simplistic spherical geometry is no longer tenable. We derive a unique one-to-one spectral relationship between the ellipsoidal harmonic coefficients of geopotential and surface mass. In conjunction with our ellipsoidal formulation, the linear transformation between spherical and ellipsoidal geopotential coefficients enables us to determine mass change on the ellipsoid from GRACE L2 data. Using the L2 data to degree 60, we show that the ellipsoidal approach determines mass change rate better than the spherical method by 3 – 4 cm/yr, equivalent to 10 – 15 % increase of total signal, in Greenland and West Antarctica. Our study emphasizes the importance of the ellipsoidal approach for quantifying mass change at polar regions from GRACE and GRACE Follow-On L2 data [Ghobadi-Far et al., 2019, Geophy. J. Int.]
A systematic review of Ayres Sensory Integration intervention for children with autism
No full textSensory integration is one of the most highly utilized interventions in autism, however, a lack of consensus exists regarding its evidence base. An increasing number of studies are investigating the effectiveness of this approach. This study used the Council for Exceptional Children (CEC) Standards for Evidence-based Practices in Special Education to evaluate the effectiveness research from 2006 to 2017 on Ayres Sensory Integration (ASI) intervention for children with autism. A systematic review was conducted in three stages. Stage 1 involved an extensive database search for relevant studies using search terms related to sensory integration and autism, interventions suggesting a sensory integration approach, and high-quality study designs. Searches yielded 19 studies that were evaluated in Stage 2. Six of these met inclusion criteria of being peer-reviewed, written in English, description of intervention this is consistent with ASI intervention, and comparison group design or single subject method employed. Prior to analysis using CEC standards, three articles were excluded because intervention details were not consistent with the core principles of ASI, or because of major methodological flaws. In Stage 3, the remaining three studies were rated using the CEC quality indicators and standards for an evidence-based practice. Two randomized controlled trials respectively met 100% and 85% of the CEC criteria items. One additional study met more than 50% of the criteria. Based on CEC criteria, ASI can be considered an evidence-based practice for children with autism ages 4-12 years old
Usual antenatal asthma management and the clinical translational potential of a fractional exhaled nitric oxide (FeNO)-based management strategy
No full textBackground: Asthma remains the most common chronic health condition to complicate pregnancy in Australia, with approximately 12.7% of pregnant women affected. If asthma is poorly controlled during pregnancy the risk of pre-eclampsia, preterm birth and low birth weight babies are increased. Guidelines including recommendations for the management of asthma during pregnancy are available, but the use of these guidelines and management recommendations in antenatal care is unknown. A new strategy aimed at reducing asthma exacerbations and improving maternal and neonatal outcomes of pregnancies affected by asthma is Fractional exhaled Nitric Oxide (FeNO)-based management. The efficacy of this strategy to reduce asthma exacerbations in pregnancy has been established, but the translational potential of it into antenatal care has not been examined. Aim: The studies contained in this thesis examine the usual antenatal asthma care currently occurring in Australia and the acceptability and feasibility of introducing a new management strategy involving the use of FeNO measurement to guide treatment. Methods: The AGREE II tool was used to appraise current asthma in pregnancy guidelines. Cross-sectional surveys were developed and distributed to healthcare professionals currently providing antenatal care and to pregnant women with asthma in order to determine ‘usual’ antenatal asthma care. Qualitative face-to-face interviews with video elicitation, involving healthcare professionals and pregnant women, were used to determine the acceptability and feasibility of implementing a FeNO-based asthma management strategy into antenatal care. Results: Recommendations for asthma management in pregnancy were found to be consistent, despite a level of ambiguity in specific elements. ‘Usual’ care described by survey respondents did not reflect guideline recommendations. The implementation of FeNObased asthma management into antenatal care was considered to be acceptable and feasible. Conclusion: An implementation strategy for FeNO-based management should be developed to provide a sustainable solution to the current inconsistent and ineffective management of asthma during pregnancy
Catalytic partial oxidation of methane to value added products by N₂0 over Fe-Based catalysts at moderate temperatures
No full textA laboratory scale process for catalytic partial methane oxidation to methanol and derivatives by N₂O over Fe-based catalysts in a continuous operation mode at moderate temperatures was constructed.
Examination of the partial methane oxidation to methanol over Fe-ZSM-5 catalysts at moderate temperatures showed that methanol and formaldehyde were produced at a temperature range from 275 °C to 400 °C with selectivity decreasing with increasing temperature. Incorporation of 0.1 wt% iron to H-ZSM-5 promoted methane and N₂O conversion, as well as the selectivity to C1-oxygenates. Further loading of iron enhanced methane conversion via complete oxidation. With an increase in the CH₄/N₂O ratio, selectivity of both carbon oxides and C1-oxygenates decreased, while the selectivity of ethylene showed an opposite trend. In addition, a relatively high GHSV elevated selectivity to desired products. In order to explore the correlation of structure properties of zeolites to active sites for methanol formation, activity and selectivity over Fe-ZSM-5, Fe-Beta and Fe-FER catalysts were studied at 350 °C for the catalytic partial oxidation of methane. Ammonia adsorption data suggested that among the studied zeolites, H-FER zeolite contained the highest concentration of framework Al atoms which are essential for the formation of active extra-framework Fe species. Fe-FER catalyst contained more active sites for N₂O conversion in comparison to Fe-Beta and Fe-ZSM-5 catalysts, as demonstrated by H₂-TPR profiles and IR spectra of NO adsorbed on the Fe zeolites. The catalytic activity studies showed that Fe-FER was the most active catalyst based on methane and N₂O conversion, and displayed the highest selectivity to C₁-oxygenates and dimethyl ether (DME), while Fe-ZSM-5 obtained the highest selectivity to ethylene among the three catalysts. Fe-ZSM-5 was found to deactivate significantly due to coke formation. Fe-FER catalysts prepared by incipient wetness impregnation (IMP), liquid ion exchange (IE) and solid state ion exchange (SSIE) methods were studied at 350 °C. UV-vis spectra indicated that the main component present in Fe-FER-IMP, Fe-FER-IE and Fe-FER-SSIE was isolated Fe species, dimeric Fe species and oligomeric iron oxides clusters, respectively. The active oxygen sites for the selective conversion of methane were identified by a TPR feature at 220 °C. This sites were also characterised by an infrared band observed at 1872 cm⁻¹ and 1892 cm⁻¹ upon adsorption of NO. The correlation of the area of the unique reduction peak in the H-TPR profiles and the area of a band at 1892 cm⁻¹ in the IR spectra of NO adsorption on the catalysts suggested that the active sites for N₂O decomposition were binuclear Fe species, and Fe-FER-SSIE contained the largest number of active Fe species among the three catalysts. The activity test showed that Fe-FER-SSIE obtained the highest N₂O decomposition at 250 °C but Fe-FER-IE achieved the highest N₂O conversion at elevated temperatures due to the greater likelihood of transformation from active oxygen species to oxygen molecules over Fe-FER-IE. Selectivity to desired products (methanol, formaldehyde, DME and ethylene) over Fe-FER-IMP, Fe-FER-IE and Fe-FER-SSIE was 12.5%, 16.5% and 19.8% (coke took into account), respectively. Formation of active oxygen species from N2O over Fe-FER catalyst prepared by SSIE method at moderate temperatures was studied using spectroscopic and solid characterisation techniques including H₂-TPR, N₂O-TPD and in situ FTIR. These bands observed at 1872 cm⁻¹ and 1892 cm⁻¹ in IR spectra of NO adsorption on catalyst were NO stretching vibrations of NO adsorbed on iron oxygen clusters, present in the zeolite cages and responsible for selective oxidation. It was shown that these oxidised clusters reacted with methane to form oxygenates but at higher temperatures formed molecular oxygen. IR Bands of surface methoxy groups were observed in significant concentration in the FTIR spectra and were suggested to be intermediate species of the selective oxidation of methane. Studies using continuous reactor demonstrated that co-feeding of methane and N₂O promoted generation of desired products from methane conversion by N₂O over Fe-FER catalyst can be enhanced by optimizing the feed ratio of CH₄/N₂O