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Robust adaptive learning control of space robot for target capturing using neural network
No full textThis article investigates the robust adaptive learning control for space robots with target capturing. Based on the momentum conservation theory, the impact dynamics is constructed to derive the relationship of generalized velocity in the pre-impact and post-impact phase. Considering the nonlinear dynamics with contact impact, the robust control using nonsingular terminal sliding mode (NTSM) and fast NTSM is designed to achieve the fast realization of the desired states. Furthermore, for the unknown dynamics of the combination system after capturing a target, the adaptive learning control is developed based on neural network and disturbance observer. Through the serial-parallel estimation model, the prediction error is constructed for the update of adaptive law. The system signals involved in the Lyapunov function are proved to be bounded and the sliding mode surface converges in finite time. Simulation studies present the desired tracking and learning performance
Appraising widespread resprouting but variable levels of postfire seeding in Australian ecosystems: The effect of phylogeny, fire regime and productivity
No full textPostfire resprouting (R+) and recruitment from seed (S+) are common resilience traits in Australian ecosystems. We classified 2696 woody Australian taxa as R+ or not (R−) and as S+ or not (S−). The proportions of these traits in Australian ecosystems were examined in relation to fire regimes and other ecological correlates, and by trait mapping on a phylogeny scaled to time. Resprouting mapped as an ancestral trait. Postfire reseeding recruitment, while ancient, is more taxonomically restricted and has evolved independently several times. Nevertheless, both R+ and S+ are common in most clades, but negatively correlated at the ecosystem level indicating an evolutionary trade-off related to differences in the severity of fire regimes, determined in part by ecosystem productivity. Thus, R+ was associated with persistence in ecosystems characterised by higher productivity and relatively frequent surface fires of moderate to low severity (fire-productivity hypothesis). S+, the fire-stimulated recruitment by seed, occurred in ecosystems characterised by infrequent but intense crown-fire and topkill, reducing competition between postfire survivors and recruits (fire-resource-competition hypothesis). Consistently large proportions of R+ or S+ imply fire has been a pervasive evolutionary selection pressure resulting in highly fire-adapted and fire-resilient flora in most Australian ecosystems
Dolphin distribution and habitat suitability in North Western Australia: Applications and implications of a Broad-Scale, Non-targeted Dataset
Get PDFUnderstanding species’ distribution patterns and the environmental and ecological interactions that drive them is fundamental for biodiversity conservation. Data deficiency exists in areas that are difficult to access, or where resources are limited. We use a broad-scale, non-targeted dataset to describe dolphin distribution and habitat suitability in remote north Western Australia, where there is a paucity of data to adequately inform species management. From 1,169 opportunistic dolphin sightings obtained from 10 dugong aerial surveys conducted over a four-year period, there were 661 Indo-Pacific bottlenose dolphin (Tursiops aduncus), 191 Australian humpback dolphin (Sousa sahulensis), nine Australian snubfin dolphin (Orcaella heinsohni), 16 Stenella sp., one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), and 290 unidentified dolphin species sightings. Maximum Entropy (MaxEnt) habitat suitability models identified shallow intertidal areas around mainland coast, islands and shoals as important areas for humpback dolphins. In contrast, bottlenose dolphins are more likely to occur further offshore and at greater depths, suggesting niche partitioning between these two sympatric species. Bottlenose dolphin response to sea surface temperature is markedly different between seasons (positive in May; negative in October) and probably influenced by the Leeuwin Current, a prominent oceanographic feature. Our findings support broad marine spatial planning, impact assessment and the design of future surveys, which would benefit from the collection of high-resolution digital images for species identification verification. A substantial proportion of data were removed due to uncertainties resulting from non-targeted observations and this is likely to have reduced model performance. We highlight the importance of considering climatic and seasonal fluctuations in interpreting distribution patterns and species interactions in assuming habitat suitability
Does an educative approach work? A reflective case study of how two Australian higher education Enabling programs support students and staff uphold a responsible culture of academic integrity
Get PDFIntroduction
Enabling education programs, otherwise known as Foundation Studies or Preparatory programs, provide pathways for students typically under-represented in higher education. Students in Enabling programs often face distinct challenges in their induction to academic culture which can implicate them in cases of misconduct. This case study addresses a gap in the enabling literature reporting on how a culture of academic integrity can be developed for students and staff in these programs through an educative approach.
Case description
This paper outlines how an educative approach to academic integrity is implemented within the Enabling programs of two Australian universities.
Discussion and reflection
This case study reflects upon an approach which makes specific reference to the key elements of ‘support’, ‘approach’ and ‘responsibility’ as highlighted in Bretag and Mahmud’s seminal paper. The paper reports a reduction in misconduct cases at the two institutions suggesting a positive correlation between the interventions and students’ understanding of ethical academic practice. This study reflects upon practitioner experiences with academic integrity investigations to evaluate the effectiveness of this approach.
Conclusions
The authors show that it is possible to ensure academic integrity practices and values are upheld within a supportive learning environment appropriate to a students’ level of study
Shallow surface and subsurface drains alleviate waterlogging and salinity in a clay-textured soil and improve the yield of sunflower in the Ganges Delta
No full textWaterlogging and salinity can occur together in salinised landscapes and restrict crop production. Drainage can alleviate waterlogging and salinity, but previous research suggested the need for deep drains, which may not be acceptable to smallholder farmers. Consequently, for the first time to our knowledge, we tested the usefulness of shallow drains in sunflower cultivation for smallholder farmers in a salt-affected, waterlogged coastal clay soil in the Ganges Delta. Experimental treatments were as follows: undrained, open surface drains (SD; 0.1 m deep, 1.8 m apart), slotted-pipe subsoil drains (SSD; 0.5 m deep, 4.5 m apart) and SSD+SD. All plots were inundated (2–3 cm above the soil surface) for 24 h before opening drains, at vegetative emergence and then at the V8 stage of plants. Relative to the most-drained (SSD+SD) treatment, the SD and SSD treatments gave 15–29% less yield, while the undrained treatment depressed yield by 48%. Soil water content (SWC) at 0–60 cm depth early in the season was 6–21, 4–10 and 3–5% less in SSD+SD treatment than in the undrained, SD and SSD treatments, respectively, while from flowering to harvest, SWC in SSD+SD was 2–4, 4–8 and 4–10% higher than in the undrained, SD and SSD treatments, respectively. In addition, soil electrical conductivity EC1:5 at 0–60 cm depth in SSD+SD treatment was 31–52, 16–38 and 11–32% lower than in the undrained, SD and SSD treatments, respectively. Across all treatments, the increases in yield due to drainage were associated with decreases in waterlogging (in the 0–30 cm layer) early in the growing season, increases in SWC late in the growing season and decreases in EC1:5 throughout the cropping season. While the shallow surface drains alone increased the yield, additional shallow subsoil drains further increased crop yield on coastal saline soils
Phenotypic variation in Vietnamese osteogenesis imperfecta patients sharing a recessive P3H1 pathogenic variant
Get PDFOsteogenesis imperfecta (OI) is a syndromic disorder of bone fragility with high variation in its clinical presentation. Equally variable is molecular aetiology; recessive forms are caused by approximately 20 different genes, many of which are directly implicated in collagen type I biosynthesis. Biallelic variants in prolyl 3-hydroxylase 1 (P3H1) are known to cause severe OI by affecting the competence of the prolyl 3-hydroxylation—cartilage associated protein—peptidyl-prolyl cis-trans isomerase B (P3H1-CRTAP-CyPB) complex, which acts on the Pro986 residue of collagen type I α 1 (COL1A1) and Pro707 collagen type I α 2 (COL1A2) chains. The investigation of an OI cohort of 146 patients in Vietnam identified 14 families with P3H1 variants. The c.1170+5G>C variant was found to be very prevalent (12/14) and accounted for 10.3% of the Vietnamese OI cohort. New P3H1 variants were also identified in this population. Interestingly, the c.1170+5G>C variants were found in families with the severe clinical Sillence types 2 and 3 but also the milder types 1 and 4. This is the first time that OI type 1 is reported in patients with P3H1 variants expanding the clinical spectrum. Patients with a homozygous c.1170+5G>C variant shared severe progressively deforming OI type 3: bowed long bones, deformities of ribcage, long phalanges and hands, bluish sclera, brachycephaly, and early intrauterine fractures. Although it remains unclear if the c.1170+5G>C variant constitutes a founder mutation in the Vietnamese population, its prevalence makes it valuable for the molecular diagnosis of OI in patients of the Kinh ethnicity. Our study provides insight into the clinical and genetic variation of P3H1-related OI in the Vietnamese population
Heuristics‐enhanced geospatial machine learning (SaaS) of an ancient Mediterranean environment
Get PDFRaw soil core physical data used in machine learning algorithms with corresponding spatial remotely sensed data is an emerging science. Using data derived from soil core samples previously collected in Universal Transverse Mercator zone 50 (Western Australia) and remotely sensed data, a model that predicted ground movement (GM) was developed specific to Australian Standards manual AS 1726–2017. This is the first approach for Australian soils and first in the world for soils older than 200 million yr. The model developed reliably predicted GM with 91.1% accuracy. The error obtained from the prediction is within acceptable limits currently used by engineers in calculations concerning soil classification for engineering purposes. Concerning the remotely sensed data analyzed, accuracy of the Atterberg limits method might be improved if additional information about soil structure (layering and horizon) or other variables (seasonal data) are built into this model. This model can be used to save on construction material costs, reduce the potential for human error associated with data collection and sample manipulation, but also fast-track (by up to 6 wk based on current wait times) building approvals while ensuring compliance to the relevant legislation. This platform also reduces the environmental effects of invasive drilling techniques. A requirement within principles of sustainable building practices, and associated with current standards commonly used by structural engineers who may seek better understanding of soil properties in Australia as a software service (with application potential in North America)
Longitudinal intronic RNA-Seq analysis of Parkinson’s disease patients reveals disease-specific nascent transcription
No full textTranscriptomic studies usually focus on either gene or exon-based annotations, and only limited experiments have reported changes in reads mapping to introns. The analysis of intronic reads allows the detection of nascent transcription that is not influenced by steady-state RNA levels and provides information on actively transcribed genes. Here, we describe substantial intronic transcriptional changes in Parkinson’s disease (PD) patients compared to healthy controls (CO) at two different timepoints; at the time of diagnosis (BL) and three years later (V08). We used blood RNA-Seq data from the Parkinson’s Progression Markers Initiative (PPMI) cohort and identified significantly changed transcription of intronic reads only in PD patients during this follow-up period. In CO subjects, only nine transcripts demonstrated differentially expressed introns between visits. However, in PD patients, 4873 transcripts had differentially expressed introns at visit V08 compared to BL, many of them in genes previously associated with neurodegenerative diseases, such as LRRK2, C9orf72, LGALS3, KANSL1AS1, and ALS2. In addition, at the time of diagnosis (BL visit), we identified 836 transcripts (e.g. SNCA, DNAJC19, PRRG4) and at visit V08, 2184 transcripts (e.g. PINK1, GBA, ALS2, PLEKHM1) with differential intronic expression specific to PD patients. In contrast, reads mapping to exonic regions demonstrated little variation indicating highly specific changes only in intronic transcription. Our study demonstrated that PD is characterized by substantial changes in the nascent transcription, and description of these changes could help to understand the molecular pathology underpinning this disease
Pigment coloration research published in the Science Citation Index Expanded from 1990 to 2020: A systematic review and bibliometric analysis
Get PDFA systematic review and bibliometric study were undertaken utilizing the Science Citation Index Expanded database from 1990 to 2020 to obtain insights into the trajectory of pigment coloration research. The study focused on the publication performance in terms of the yearly production and citations, as well as mainstream journals, categories of the Web of Sciences, leading nations, well-known institutions, and research trends. The survey found that the yearly output of scholarly publications on pigment coloration research climbed gradually throughout the first quarter of the study period and then increased substantially in the latter five years. The present research emphasis and future trends were examined after summarizing the paper title and abstract analyses, author keyword analysis, and the most regularly used keywords derived from words in KeyWords Plus. To expand its reach in numerous application areas, pigment coloration research will continue to focus on improving pigment qualities