Ecological genomics and adaptation of rosewoods Dalbergia cochinchinensis and D. oliveri for conservation and restoration

Global biodiversity, in particular tropical forests, is decreasing under both environmental change and anthropogenic disturbance. Environmental change alters species’ adaptability to their current habitat, leading to loss of fitness and range shift, while anthropogenic disturbance reduces their adaptive capacity. Conserving and restoring threatened species and ecosystems thus become a grand challenge for the 21st century. This thesis studies two threatened rosewood species, Dalbergia cochinchinensis and D. oliveri, which are illegally exploited for their valuable timber in the Greater Mekong Subregion. They became the world’s most trafficked wild product between 2005 and 2014, amounting to ~40% of the total global trade. Conservation efforts grew in the last decade to tackle the range-wide challenge, aiming to improve the species’ survival, amplify the production of genetic materials, and designate more conservation units. However, a sustainable supply of genetic materials can meet several challenges that compromise the effectiveness of a restoration programme, namely the genetic bottlenecks, maladaptation, and climate change. While knowledge of adaptation can predict and mitigate these risks, standard study approaches such as common garden experiments have become impractical due to the acute threats of illegal logging in these two species, which are lacking in a priori knowledge. This thesis aims to increase the knowledge of genetic and physiological underpinning of adaptation in the two Dalbergia species with relevance to application in conservation and restoration strategies. This thesis presents a rich body of genomic resources such as chromosome-scale genomes and reference transcriptomes, which advance the progress in less-represented angiosperm tree genomes and woody legume genomes and enable studies in genetic diversity. Comparative genomic studies revealed insight into the evolution and potential adaptive role of of certain gene families in tropical Dalbergia species. The landscape genomic study provides a comprehensive scan of adaptive signals and reports significant differences of the adaptive variation between the two species, where D. cochinchinensis is driven by temperature variability and D. oliveri by precipitation variability. The controlled stress experiment provides a physiological understanding of how the two species regulate their water relations and photosynthetic apparatus to respond to drought differently, where D. cochinchinensis has a more anisohydric behaviour than D. oliveri. These contrasting patterns of adaptation indicate how the two species may differentiate their niches, while co-occurring in some habitats. The knowledge of adaptive variation identifies hotspots of local adaptation and vulnerability towards climate change, and thus are expected to help conservation practitioners delineate conservation units, compare provenances for assisted germplasm transfer, and prioritise conservation actions. It also opens new avenues for future research, including combining common garden experiments and genomic approaches to more fully unravel genotype-phenotype-environment relationships

Improper Ferroelectric Polarisation in a Perovskite driven by Inter-site Charge Transfer and Ordering

It is of great interest to design and make materials in which ferroelectric polarisation is coupled to other order parameters such as lattice, magnetic and electronic instabilities. Such materials will be invaluable in next-generation data storage devices. Recently, remarkable progress has been made in understanding improper ferroelectric coupling mechanisms that arise from lattice and magnetic instabilities. However, although theoretically predicted, a compact lattice coupling between electronic and ferroelectric (polar) instabilities has yet to be realised. Here we report detailed crystallographic studies of a novel perovskite Hg$^{\textbf{A}}$Mn$^{\textbf{A'}}_{3}$Mn$^{\textbf{B}}_{4}$O$_{12}$ that is found to exhibit a polar ground state on account of such couplings that arise from charge and orbital ordering on both the A' and B-sites, which are themselves driven by a highly unusual Mn$^{A'}$-Mn$^B$ inter-site charge transfer. The inherent coupling of polar, charge, orbital and hence magnetic degrees of freedom, make this a system of great fundamental interest, and demonstrating ferroelectric switching in this and a host of recently reported hybrid improper ferroelectrics remains a substantial challenge.Comment: 9 pages, 7 figure

Outage probability analysis in DF power-splitting full-duplex relaying network with impact of Co-channel interference at the destination

Nowadays, improving the WPCN efficiency problem is the leading research direction in the communication network. In this research, the outage probability (OP) analysis in DF power-splitting (PS) full-duplex (FD) relaying network with impact of co-channel interference at the destination is proposed and investigated. In the system model section, we present the DF PS FD Relaying Network with Impact of Co-channel interference at the destination. Then in the system performance section, we analyze and derive the closed-form expression of the OP and investigate the effect of the main system parameters on the system network performance. Then, we perform the Monte Carlo simulation to verify the analytical section. This research can provide a new recommendation for the communication network

A Deep Learning Approach to Denoise Optical Coherence Tomography Images of the Optic Nerve Head

Purpose: To develop a deep learning approach to de-noise optical coherence tomography (OCT) B-scans of the optic nerve head (ONH). Methods: Volume scans consisting of 97 horizontal B-scans were acquired through the center of the ONH using a commercial OCT device (Spectralis) for both eyes of 20 subjects. For each eye, single-frame (without signal averaging), and multi-frame (75x signal averaging) volume scans were obtained. A custom deep learning network was then designed and trained with 2,328 "clean B-scans" (multi-frame B-scans), and their corresponding "noisy B-scans" (clean B-scans + gaussian noise) to de-noise the single-frame B-scans. The performance of the de-noising algorithm was assessed qualitatively, and quantitatively on 1,552 B-scans using the signal to noise ratio (SNR), contrast to noise ratio (CNR), and mean structural similarity index metrics (MSSIM). Results: The proposed algorithm successfully denoised unseen single-frame OCT B-scans. The denoised B-scans were qualitatively similar to their corresponding multi-frame B-scans, with enhanced visibility of the ONH tissues. The mean SNR increased from $4.02 \pm 0.68$ dB (single-frame) to $8.14 \pm 1.03$ dB (denoised). For all the ONH tissues, the mean CNR increased from $3.50 \pm 0.56$ (single-frame) to $7.63 \pm 1.81$ (denoised). The MSSIM increased from $0.13 \pm 0.02$ (single frame) to $0.65 \pm 0.03$ (denoised) when compared with the corresponding multi-frame B-scans. Conclusions: Our deep learning algorithm can denoise a single-frame OCT B-scan of the ONH in under 20 ms, thus offering a framework to obtain superior quality OCT B-scans with reduced scanning times and minimal patient discomfort

Sr[Mg3SiN4]Eu2+ phosphor: solution for enhancing the optical properties of the 5600K remote-packaging WLEDs

In the last decade, light-emitting diodes (LEDs), which based on spontaneous light emission in semiconductors can be considered as the main light sources for civil and industrial purposes. In this paper, we presented and investigated the effect of the Sr[Mg3SiN4]Eu2+ concentration on the optical properties of the 5600K remote-packaging WLEDs (RP-WLEDs). We use the Mat Lab and the LightTool software to investigate the effect of the Sr[Mg3SiN4]Eu2+ concentration on the CRI, CQS, D-CCT and LO of the 5600K RP-WLEDs. From the result, we can state that the concentration of the Sr[Mg3SiN4]Eu2+ influenced on the CRI, CQS, D-CCT and LO of the RP-WLEDs. The red Sr[Mg3SiN4]Eu2+ phosphor can be considered as the novel recommendation for LEDs industry

Creative Arts-Based Therapies for Stroke Survivors: A Qualitative Systematic Review

Background: Stroke is a life-threating cerebrovascular disease. Without proper and immediate treatment, it can cause long-term disabilities and even death. While current rehabilitation focuses on functional needs, it does not fully address the psychosocial issues. Creative arts-based therapies, however, may have the potential to be of assistance.Methods: A systematic review was conducted to synthesize the qualitative findings of the stroke survivors' positive and negative experiences in participating in creative arts-based therapies. A systematic literature search was conducted across diverse databases. A thematic synthesis was adopted to analyze the results from different qualitative studies and mix-method studies.Results: Among the 367 studies extracted from various databases, 11 studies met the inclusion criteria and were of acceptable quality. The following five analytical themes were identified: functional restoration, psychological support, social engagement, spiritual experience, and short-comings and barriers.Conclusion: Creative arts-based therapies have demonstrated their strengths in addressing psychosocial needs for stroke survivors. Different art modalities are perceived to be useful in achieving different therapeutic goals. Therapies based on a single art modality or combined modalities have different specialties and characteristics. Further research is needed to demonstrate the differential benefits or special advantages of using single or multiple art modalities as well as having qualified therapists in creative arts-based therapies

Hybrid TSR-PSR in nonlinear EH half duplex network: system performance analysis

Nowadays, harvesting energy (EH) from green environmental sources and converting this energy into the electrical energy used in purpose to supply the communication network devices is considered the main research direction. In this research, we investigate the hybrid TSR-PSR Nonlinear Energy Harvesting (EH) Half-duplex (HD) Relaying network in terms of the Success Probability (SP). For this purpose, we derive the integral-form of the system SP. In addition, we use the Monte Carlo simulation for verifying the correctness of the analytical expression. We can see in the research results that all the simulation and analytical values are the same in connection with all primary system parameters

Assessment of Chitosan-Affected Metabolic Response by Peroxisome Proliferator-Activated Receptor Bioluminescent Imaging-Guided Transcriptomic Analysis

Chitosan has been widely used in food industry as a weight-loss aid and a cholesterol-lowering agent. Previous studies have shown that chitosan affects metabolic responses and contributes to anti-diabetic, hypocholesteremic, and blood glucose-lowering effects; however, the in vivo targeting sites and mechanisms of chitosan remain to be clarified. In this study, we constructed transgenic mice, which carried the luciferase genes driven by peroxisome proliferator-activated receptor (PPAR), a key regulator of fatty acid and glucose metabolism. Bioluminescent imaging of PPAR transgenic mice was applied to report the organs that chitosan acted on, and gene expression profiles of chitosan-targeted organs were further analyzed to elucidate the mechanisms of chitosan. Bioluminescent imaging showed that constitutive PPAR activities were detected in brain and gastrointestinal tract. Administration of chitosan significantly activated the PPAR activities in brain and stomach. Microarray analysis of brain and stomach showed that several pathways involved in lipid and glucose metabolism were regulated by chitosan. Moreover, the expression levels of metabolism-associated genes like apolipoprotein B (apoB) and ghrelin genes were down-regulated by chitosan. In conclusion, these findings suggested the feasibility of PPAR bioluminescent imaging-guided transcriptomic analysis on the evaluation of chitosan-affected metabolic responses in vivo. Moreover, we newly identified that downregulated expression of apoB and ghrelin genes were novel mechanisms for chitosan-affected metabolic responses in vivo