An Evaluation of Sinhala Language NLP Tools and Neural Network Based POS Taggers

PoS sildistamine on fundamentaalne probleem, NLP domeenis ja PoS sildistajaid (ühestajaid) kasutatakse selle väljakutse lahendamiseks. Kuigi reeglipõhist, tõenäosuslikku või süvaõppe lähenemisviisi saab kasutada, PoS sildistaja (ühestaja) väljatöötamiseks, aga süvaõppel põhinevad PoS sildistajad (ühestajad) on paremaid tulemusi näidanud. Kõik senimaani läbi viidud singala keele PoS sildistamise uuringud, on läbi viidud kasutades reeglipõhist ja tõenäosuslikku meetodit. See uurimistöö keskendub süvaõppel põhinevate PoS sildistamise (ühendamise) arendamisele ja hindamisele, kasutades singala keele jaoks LSTM võrku. Selle uurimistöö käigus koolitasime viite (5) süvaõppele tuginevat PoS sildistamise (ühendamise) mudelit, kahel erineval andmekogumil ja hindasime nende mudelite tulemusi. Hindamistulemused on näidanud, et süvaõppel põhinevaid PoS sildistajaid (ühestajaid), saab singala keele jaoks kasutada ja nende jõudlus on parem, kui olemasolevad reeglipõhised või tõenäosuslikud PoS sildistajad (ühestajad).Part Of Speech tagging is a fundamental problem in the NLP domain and Part Of Speech taggers are used to address this challenge. Though Rule based, probabilistic or deep learning approaches can be used to develop a Part Of Speech tagger, deep learning based Part Of Speech taggers have shown better results. All the Part Of Speech tagging researches that have been carried out so far for the Sinhala language have been done using rule based and probabilistic approaches. This research focuses on developing and evaluating deep learning based Part Of Speech taggers using LSTM network for the Sinhala language.In this research we trained 5 deep learning based Part Of Speech tagging models on two different data sets and evaluated the results of those models. The evaluation results have shown that deep learning based Part Of Speech taggers can be used for Sinhala language and their performance is better than the existing rule based or probabilistic Part Of Speech taggers

Genomic insights into rapid speciation within the world’s largest tree genus Syzygium

Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification

Genomic insights into rapid speciation within the world's largest tree genus Syzygium

Acknowledgements Y.W.L. was supported by a postgraduate scholarship research grant from the Ministry of National Development, Singapore awarded through the National Parks Board, Singapore (NParks; NParks’ Garden City Fund). Principal research funding from NParks and the School of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore, is acknowledged. We thank Peter Preiser, Associate Vice President for Biomedical and Life Sciences, for facilitating NTU support, and Kenneth Er, CEO of NParks, for facilitating research funding through that organisation. V.A.A. and C.L. were funded by SBS, NTU for a one-year research leave. V.A.A. and C.L. also acknowledge support from the United States National Science Foundation (grants 2030871 and 1854550, respectively). S.R. was supported by a postdoctoral research fellowship under the NTU Strategic Plant Programme. S.R. and N.R.W.C. acknowledge funding from NTU start-up and the Academy of Finland (decisions 318288, 319947) grants to J.S. Fieldwork conducted by Y.W.L. was supported by an Indonesian Government RISTEK research permit (Application ID: 1517217008) and an Access License from the Sabah State government [JKM/MBS.1000-2/2JLD.7(84)]. T.N.C.V. is grateful to the Assemblée de la Province Nord and Assemblée de la Province Sud (New Caledonia) for facilitating relevant collection permits. A.N. was partly supported by the Research Project Promotion Grant (Strategic Research Grant No. 17SP01302) from the University of the Ryukyus, and partly by the Environment Research and Technology Development Fund (JPMEERF20204003) from the Environmental Restoration and Conservation Agency of Japan. Fieldwork in Fiji conducted by R.B. was hosted and facilitated by Elina Nabubuniyaka-Young (The Pacific Community’s Centre for Pacific Crops and Trees, Fiji). We thank the NTU-Smithsonian Partnership for tree data obtained for the Bukit Timah Nature Reserve (BTNR) long-term forest dynamics plots. Administrative support provided by Mui Hwang Khoo-Woon and Peter Ang at the molecular laboratory of the Singapore Botanic Gardens (SBG) is acknowledged. Rosie Woods and Imalka Kahandawala (DNA and Tissue Bank, Royal Botanic Gardens, Kew) facilitated additional DNA samples. Daniel Thomas (SBG) and Yan Yu (Sichuan University) commented on biogeographical analyses. NovogeneAIT in Singapore is acknowledged for personalised sequencing service.Peer reviewedPublisher PD

Genomic insights into rapid speciation within the world's largest tree genus Syzygium

The relative importance of the mechanisms underlying species radiation remains unclear. Here, the authors combine reference genome assembly and population genetics analyses to show that neutral forces have contributed to the radiation of the most species-rich tree genus Syzygium. Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification.Peer reviewe

Range extension of Heliogomphus lyratus Fraser, 1933 (Anisoptera: Gomphidae) with notes on its identification, habits and habitat

Heliogomphus lyratus is a Sri Lankan endemic dragonfly.  It is one of the rarest Sri Lankan dragonflies with only three hitherto known localities.  Apart from the faunistic records of the species, nothing much is known of its biology or ecology.  We report five new distribution localities for Heliogomphus lyratus with seven different observations.  All these new localities extend the previously known range of the species.  We also provide some notes on its field identification, habits and habitat based on our field observations. </div

Variation of floristic diversity, community composition, endemism, and conservation status of tree species in tropical rainforests of Sri Lanka across a wide altitudinal gradient

Abstract Tropical rainforests in Sri Lanka are biodiversity hotspots, which are sensitive to anthropogenic disturbance and long-term climate change. We assessed the diversity, endemism and conservation status of these rainforests across a wide altitudinal range (100–2200 m above sea level) via a complete census of all trees having ≥ 10 cm diameter at breast height in ten one-hectare permanent sampling plots. The numbers of tree families, genera and species and community-scale tree diversity decreased with increasing altitude. Tree diversity, species richness and total basal area per ha across the altitudinal range were positively associated with long-term means of maximum temperature, annual rainfall and solar irradiance. Percentage of endangered species increased with increasing altitude and was positively associated with cumulative maximum soil water deficit, day-night temperature difference and high anthropogenic disturbance. Percentage of endemic species was greater in the lowland rainforests than in high-altitude montane forests. Nearly 85% of the species were recorded in three or less plots, which indicated substantial altitudinal differentiation in their distributions. Less than 10 individuals were recorded in 41% of the endemic species and 45% of the native species, which underlined the need for urgent conservation efforts across the whole altitudinal range

Genomic insights into rapid speciation within the world’s largest tree genus [PREPRINT].

Species radiations have long fascinated biologists, but the contribution of adaptation to observed diversity and speciation is still an open question. Here, we explore this question using the clove genus, Syzygium, the world’s largest genus of tree species comprising approximately 1200 species. We dissect Syzygium diversity through shotgun sequencing of 182 distinct species and 58 additional as-yet unidentified taxa, and assess their genetic diversity against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that Syzygium grande shares a whole genome duplication (WGD) event with other Myrtales. Genomic analyses confirm that Syzygium originated in Sahul (Australia-New Guinea), and later diversified eastward to the Hawaiian Islands and westward in multiple independent migration events. The migrations were associated with bursts of speciation events, visible by poorly resolved branches on phylogenies and networks, some of which were likely confounded by incomplete lineage sorting. Clinal genomic variation in some sublineages follows phylogenetic progression, which coupled with sympatric occurrences of distantly related species suggests that both geographic and ecological speciation have been important in the diversification of Syzygium. Together, these results point to a mixture of both neutral and adaptive drivers having contributed to the radiation of the genus