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  • Breum Honore posted an update 6 days, 22 hours ago

    We explore the origins of the extraordinary plant diversity in the Qinghai-Tibetan Plateau (QTP) using Orchidinae (Orchidaceae) as a model. Our results indicate that six major clades in Orchidinae exhibited substantial variation in the temporal and spatial sequence of diversification. Our time-calibrated phylogenetic model suggests that the species-richness of Orchidinae arose through a combination of in situ diversification, colonisation, and local recruitment. There are multiple origins of species-richness of Orchidinae in the QTP, and pre-adaptations in clades from North Temperate and alpine regions were crucial for in situ diversification. The geographic analysis identified 29 dispersals from Asia, Africa and Europe into the QTP and 15 dispersals out. Most endemic species of Orchidinae evolved within the past six million years.The Drosophila montium species group is a clade of 94 named species, closely related to the model species D. melanogaster. The montium species group is distributed over a broad geographic range throughout Asia, Africa, and Australasia. Species of this group possess a wide range of morphologies, mating behaviors, and endosymbiont associations, making this clade useful for comparative analyses. We use genomic data from 42 available species to estimate the phylogeny and relative divergence times within the montium species group, and its relative divergence time from D. melanogaster. To assess the robustness of our phylogenetic inferences, we use 3 non-overlapping sets of 20 single-copy coding sequences and analyze all 60 genes with both Bayesian and maximum likelihood methods. Our analyses support monophyly of the group. Apart from the uncertain placement of a single species, D. baimaii, our analyses also support the monophyly of all seven subgroups proposed within the montium group. Our phylograms and relative chronograms provide a highly resolved species tree, with discordance restricted to estimates of relatively short branches deep in the tree. In contrast, age estimates for the montium crown group, relative to its divergence from D. melanogaster, depend critically on prior assumptions concerning variation in rates of molecular evolution across branches, and hence have not been reliably determined. We discuss methodological issues that limit phylogenetic resolution – even when complete genome sequences are available – as well as the utility of the current phylogeny for understanding the evolutionary and biogeographic history of this clade.The Indian subcontinent’s unique geological history is reflected in the diverse assemblage of its biota. The blindsnake superfamily Typhlopoidea, with its unique mix of ancient as well as younger lineages in Asia, provides an opportunity to understand the various biotic exchange scenarios proposed for the Indian landmass. In this study, we aim to understand the biogeographic origins of the four genera of typhlopoids found in India and to decipher their times and modes of arrival in the subcontinent. Five nuclear markers were sequenced for 12 samples collected from across India, encompassing all four genera under study. Published sequences of typhlopoid genera were compiled and combined with Indian sequences to generate a global dataset. Phylogenetic relationships were reconstructed using maximum likelihood and Bayesian inference methods. click here Divergence times were estimated using BEAST 1.8.2. Ancestral geographical ranges were estimated using DEC + J, implemented in BioGeoBEARS. Divergence time estimates suggest that Gerrhopilus is an ancient lineage, and the lineage leading to it was present on the Indian landmass since the last 100 million years. The other three genera are more recent dispersals into India, possibly trans-oceanic. Biogeographic reconstructions suggest an East Gondwanan origin for Typhlopoidea, an African origin for Grypotyphlops and an Asian origin for Indotyphlops and Argyrophis. It appears that India harbours a combination of ancient and more recently dispersed lineages of typhlopoids. The genus Gerrhopilus is of Gondwanan origin that likely dispersed out of India into Southeast Asia. The other genera are intrusive elements that dispersed into India from Africa (Grypotyphlops) and Asia (Indotyphlops and possibly Argyrophis) post break-up of Gondwana. Thus, our study provides further evidence on the ability of blindsnakes to undergo long distance trans-oceanic dispersal. Results also suggest an Asian origin for typhlopoids from Australasia, Philippines and Wallacea.There has been a surge in the use of transdermal drug delivery systems (TDDS) for the past few years. The market of TDDS is expected to reach USD 7.1 billion by 2023, from USD 5.7 billion in 2018, at a CAGR of 4.5%. Microneedles (MNs) are a novel class of TDDS with advantages of reduced pain, low infection risk, ease of application, controlled release of therapeutic agents, and enhanced bioavailability. Biodegradable MNs fabricated from natural polymers have become the center of attention among formulation scientists because of their recognized biodegradability, biocompatibility, ease of fabrication, and sustainable character. In this review, we summarize the various polysaccharides and polypeptide based biomaterials that are used to fabricate biodegradable MNs. Particular emphasis is given to cellulose and its derivatives, starch, and complex carbohydrate polymers such as alginates, chitosan, chondroitin sulfate, xanthan gum, pullulan, and hyaluronic acid. Additionally, novel protein-based polymers such as zein, collagen, gelatin, fish scale and silk fibroin (polyamino acid) biopolymers application in transdermal drug delivery have also been discussed. The current review will provide a unique perspective to the readers on the developments of biodegradable MNs composed of carbohydrates and protein polymers with their clinical applications and patent status.Paper industry uses cationic polymers for imparting strong bonds with pulp furnish to enhance strength properties. Due to environmental reasons, emphasis is on utilization of biobased polymers in place of synthetic. Sugarcane bagasse, an agro-industrial waste, was processed for extraction of alpha cellulose and preparation of cationic derivative. Reaction conditions were optimized to achieve highly substituted cationic derivative with insertion of 2-hydroxy-3-(trimethylammonium) propyl group. Artificial neural network (ANN) was applied to analyze the experimental data for cationization modeling. Maximum degree of substitution 0.66, was achieved at 5.0 M NaOH/anhydro glucose unit (AGU), 20 °C alkalization temperature, 8 min alkalization time, 3.5 M/AGU etherification agent concentration, 45 min time and 60 °C etherification reaction temperature. The experimental results showed that mean square error values for input parameters were significantly low. The ANN based regression values of the output, and computed values of target were close to unity.

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