'Through the looking glass' : diversity and its functional significance in marine benthic microbial eukaryotes

University of Technology Sydney. Faculty of Science.Marine microbial eukaryotes are of immense ecological and evolutionary significance in marine ecosystems. Understanding their biodiversity and functional evolutionary traits are key to improving our understanding of marine ecosystem functioning. The East Australian Current (EAC) is a global climate change hotspot, and yet we lack in our understanding of its impact on phytoplankton distribution and dynamics. Ostreopsis species have been reported to cause severe blooms and produce palytoxin (PLTX) – like compounds all around the globe but we do not have basic information on the distribution and dynamics of Ostreopsis species in Australia. In this dissertation, I established the first comprehensive report of Ostreopsis species from Australian waters and explored cryptic diversity and functional traits in this genus. Extensive sampling along a north-south gradient of 1800 km from sub-tropical to temperate waters yielded the identification of three species, including a novel pseudo-cryptic Ostreopsis rhodesae from the Great Barrier Reef, along with Ostreopsis cf. ovata. Ostreopsis cf. siamensis was identified at all locations and its eco-physiological traits and genetic population structure were investigated. The genetic diversity in the northern subtropical locations was greater compared to the more southern locations, reflecting a longstanding divergence and local radiations originating from the ancestral population and a potential southward range expansion, which may be related to the intensification of the EAC over the past century. Intra- and inter-population variations in physiological traits were investigated to understand its range expansion and functional trade-offs. This is the first study to our knowledge to report growth rates, cell size, cellular toxic concentrations and photobiological parameters on fifty-three clones of a marine protist, in order to investigate intra-specific diversity in key functional traits. The toxin biosynthesis pathway in the three species was investigated using de novo transcriptomics and compared to Coolia malayensis. All essential domains needed to synthesize a PLTX-like carbon backbone were identified in the three Ostreopsis species and were also found in the non-PLTX producing C. malayensis. Putative molecules with potential polyketide-like backbone structures were reported in this investigation using non-targeted metabolomics, suggesting a greater diversity of polyketide compounds amongst these species than previously anticipated. Results from this dissertation add to the knowledge of species biodiversity, population structures, eco-physiological traits and toxin biosynthesis mechanisms in marine microbial eukaryotes, and Ostreopsis species in particular

RecXplainer: Post-Hoc Attribute-Based Explanations for Recommender Systems

Recommender systems are ubiquitous in most of our interactions in the current digital world. Whether shopping for clothes, scrolling YouTube for exciting videos, or searching for restaurants in a new city, the recommender systems at the back-end power these services. Most large-scale recommender systems are huge models trained on extensive datasets and are black-boxes to both their developers and end-users. Prior research has shown that providing recommendations along with their reason enhances trust, scrutability, and persuasiveness of the recommender systems. Recent literature in explainability has been inundated with works proposing several algorithms to this end. Most of these works provide item-style explanations, i.e., `We recommend item A because you bought item B.' We propose a novel approach, RecXplainer, to generate more fine-grained explanations based on the user's preference over the attributes of the recommended items. We perform experiments using real-world datasets and demonstrate the efficacy of RecXplainer in capturing users' preferences and using them to explain recommendations. We also propose ten new evaluation metrics and compare RecXplainer to six baseline methods.Comment: Awarded the Best Student Paper at TEA Workshop at NeurIPS 2022. 13 page

Factors determining failure of intertrochanteric fracture fixation with a dynamic hip screw: a retrospective analysis

Background: The intertrochanteric fractures are extra capsular fractures of proximal femur in the trochanteric region. Different fixation techniques were tried for intertrochanteric fractures, with variety of implants but the dynamic hip screw fixation is most widely accepted treatment. However, several authors have concluded that sliding compression screws may be associated with several complications such as perforation of the femoral head, loss of reduction caused by excessive sliding of the lag screw, non-union, shortening of the affected limb and pain. This study was carried out to ascertain the factors that contributed to mechanical failure at our institute.Methods: We retrospectively reviewed 92 patients with unilateral intertrochanteric fracture treated with a sliding hip screw between July 2015 and April 2017. Postoperative radiographs were studied for any loss of reduction, which was defined as a varus deformity greater than 10°, perforation of the femoral head, extrusion of the lag screw of more than 20 mm, or metal failure. The Pearson chi-square test was used to assess the relationship between failure and osteoporosis. A p value of less than 0.05 was considered to be significant.Results: Results revealed a significant relationship between failure and osteoporosis. A possible relationship between the stability of the fracture on Evans’ classification and osteoporosis on Singh’s index was investigated which revealed a high positive correlation between the failure rates of unstable fractures with osteoporosis.Conclusions: An unstable fracture combined with osteoporosis, has higher percentage of fixation failure leading to other methods of treatment like hemiarthroplasty.

TRADITIONAL HEALING WITH ANIMALS (ZOOTHERAPY) BY THE MAJOR ETHNIC GROUP OF KARBI ANGLONG DISTRICT OF ASSAM, INDIA

Objective: To survey and document the traditional knowledge related to medicinal uses of animals among the ethnic groups in Karbi Anglong district of Assam. Methods: A long term field survey was conducted from July 2008 to October 2009 by performing personal interviews through structured questionnaire with more than 500 respondents, who provided information regarding the use of different animals and their products in their traditional medicine. Most of the information on the use of various animals in traditional medicine by them was provided by elderly people in the age groups of more than 50 years. Results: A total of 48 different animals were recorded to be used for different ethno-medical purposes against various diseases, including tuberculosis, asthma, cancer, paralysis, jaundice, leprosy, toothache, rabies, dysentery, baldness, rheumatism, arthritis, weakness, piles etc. The highest percentage of animals used for traditional treatment is mammals (about 40%) followed by insects (about 21%) and birds (about 19%). Conclusion: The findings reveal a rich traditional knowledge of indigenous people of Karbi Anglong about the use of animals and their product in traditional medicine. It is suggested that this kind of traditional knowledge should be included into the scientific literature for the conservation and management of medicinal faunistic resources

Bio-efficacy of tank mixed herbicides for control of complex weed flora in soybean (Glycine max L. Merril)

A field experiment was conducted at ZARS, Jhabua (M.P.) during kharif 2014 to find out most suitable and efficient method of weed control in soybean. The experiment consisted of nine treatments laid out in randomized block design with three replications. All the weed management practices led to significant reduction in density and dry matter of weeds as compared to weedy check. Two hand weeding (20 & 40 DAS) recorded lowest weed density (4.9/ m2), weed dry matter (22.35 g/m2) with highest weed control efficiency of 59.67% and found at par with the application of Chlorimuron Ethyl @ 9gm /ha + Quizalofop-p-ethyl @ 50 g /ha (density 5.48/ m2, dry matter 26.62 g/m2 and WCE of 51.97%) and Imazethapyr @ 35 g /ha + Imazamox @ 35 g/ha (density 6.13/ m2, dry matter 26.00 g/m2 and WCE of 53.08%). Maximum yield of 1782 kg/ha was recorded in two hand weeding (20 & 40 DAS) closely followed by Chlorimuron Ethyl @ 9gm /ha + Quizalofop-p-ethyl @ 50 g /ha (1723 kg/ha) and Imazethapyr @ 35 g / ha + Imazamox @ 35 g/ha (1697 kg/ha). Reduction in soybean yield in weedy check to be recorded is 38.78 per cent when compared to weed free and 36.68 per cent in comparison to Chlorimuron Ethyl @ 9gm /ha + Quizalofopp-ethyl @ 50 g /ha. However, highest Benefit to Cost ratio is recorded in Chlorimuron Ethyl +Quizalofop-p-ethyl (3.26) closely followed by Imazethapyr + Imazamox (3.22) and Weed free (3.21)

Modelling prejudice and its effect on societal prosperity

Existing studies of the multi-group dynamics of prejudiced societies focus on the social- psychological knowledge behind the relevant processes. We instead create a multi-agent framework that simulates the propagation of prejudice and measures its tangible impact on prosperity. Levels of prosperity are tracked for individuals as well as larger social structures including groups and factions. We model social interactions using the Continuous Prisoner's Dilemma (CPD) and a new agent type called a prejudiced agent. Our simulations show that even modeling prejudice as an exclusively out-group phenomenon nonetheless generates implicit in-group promotion, leading to higher relative prosperity of a prejudiced population. This skew in prosperity is seen to be correlated to factors such as size difference between groups, and the fraction of prejudiced agents in a group. Our model is a step towards a deeper understanding of the origins, propagation, and ramifications of prejudice through simulative studies grounded in apt theoretical backgrounds