Score Following with Hidden Tempo Using a Switching State-Space Model

What is Score Following? The score-following problem involves building a computer program that can trace musical events in a given musical score during a live performance

PIANO SCORE FOLLOWING WITH HIDDEN TIMBRE OR TEMPO USING SWITCHING KALMAN FILTERS

Thesis (Ph.D.) - Indiana University, University Graduate School/Luddy School of Informatics, Computing, and Engineering, 2020Score following is an AI technique that enables computer programs to “listen to” music: to track a live musical performance in relation to its written score, even through variations in tempo and amplitude. This ability can be transformative for musical practice, performance, education, and composition. Although score following has been successful on monophonic music (one note at a time), it has difficulty with polyphonic music. One of the greatest challenges is piano music, which is highly polyphonic. This dissertation investigates ways to overcome the challenges of polyphonic music, and casts light on the nature of the problem through empirical experiments. I propose two new approaches inspired by two important aspects of music that humans perceive during a performance: the pitch profile of the sound, and the timing. In the first approach, I account for changing timbre within a chord by tracking harmonic amplitudes to improve matching between the score and the sound. In the second approach, I model tempo in music, allowing it to deviate from the default tempo value within reasonable statistical constraints. For both methods, I develop switching Kalman filter models that are interesting in their own right. I have conducted experiments on 50 excerpts of real piano performances, and analyzed the results both case-by-case and statistically. The results indicate that modeling tempo is essential for piano score following, and the second method significantly outperformed the state-of-the-art baseline. The first method, although it did not show improvement over the baseline, still represents a promising new direction for future research. Taken together, the results contribute to a more nuanced and multifaceted understanding of the score-following problem

Cytotoxicity of hydroxydihydrobovolide and its pharmacokinetic studies in Portulaca oleracea L. extract

Hydroxydihydrobovolide (HDB) was for the first time isolated from Portulaca oleracea L. and then its cytotoxicity against SH-SYTY cells was studied. Moreover, a rapid and sensitive ultra-high performance liquid chromatographic (UHPLC) method with bergapten as internal standard (IS) was developed and validated to investigate the pharmacokinetics of HDB in rats after intravenous and oral administrations of extract (POE). The UHPLC analysis was performed on a Diamonsil C18 analytical column, using acetonitrile-water (35:65, v/v) as the mobile phase with UV detection at 220 nm. The calibration curve was linear over the range of 0.2-25 µg/mL in rat plasma. The average extraction recovery was from 90.1 to 98.9%, and the relative standard deviations (RSDs) of the intra- and inter-day precisions were less than 4.7 and 4.1%, respectively. The results showed that 50 µM HDB had significant cytotoxicity on the SH-SY5Y cells, which was rapidly distributed with a Tmax of 11 min after oral administration and presented a low absolute bioavailability, 4.12%

Simulation and Prediction of the Impact of Climate Change Scenarios on Runoff of Typical Watersheds in Changbai Mountains, China

Simulating the hydrological process of a river basin helps to understand the evolution of water resources in the region and provides scientific guidance for water resources allocation policies between different river basins and water resources management within the river basin. This paper provides a scientific basis for the sustainable development of regional water resources and an accurate grasp of the future change trend of runoff by analyzing the hydrological process response of runoff in typical watersheds in Changbai Mountains, China, to climate change. The applicability of the HEC-HMS (The Hydrologic Engineering Center’s-Hydrologic Modeling System) hydrological model in the watershed is verified by calibrating and verifying the daily rainfall-runoff process in the watershed during the wet season from 2006 to 2017. The daily rainfall data of the two scenarios SSP2-4.5 and SSP5-8.5 under the BCC-CSM2-MR model in the 2021–2050 CMIP6 plan were downscaled and interpolated to in-basin stations to generate future daily precipitation series to predict runoff response to future climate change. The daily rainfall data of the two scenarios were downscaled and interpolated to the stations in the basin to generate future daily rainfall series to predict the runoff response under future climate changes. The average certainty coefficient of the HEC-HMS model for daily runoff simulation reached 0.705; the rainfall in the basin under the two climate scenarios of SSP2-4.5 and SSP5-8.5 in the next 30 years (2021–2050) will generally increase, and rainfall will be more evenly distributed in the future; the outlet flow of the basin will increase during the wet season (June–September) in the next 30 years, but it is lower than the historically measured value; the peak flow of the future will appear at most in August and September. The peak flow current time mostly appears in July and August. The time of peak occurrence has been delayed

Mitochondrial dysfunction induced by bedaquiline as an anti-Toxoplasma alternative

Abstract Toxoplasma gondii is a zoonotic parasite that infects one-third of the world’s population and nearly all warm-blooded animals. Due to the complexity of T. gondii’s life cycle, available treatment options have limited efficacy. Thus, there is an urgent need to develop new compounds or repurpose existing drugs with potent anti-Toxoplasma activity. This study demonstrates that bedaquiline (BDQ), an FDA-approved diarylquinoline antimycobacterial drug for the treatment of tuberculosis, potently inhibits the tachyzoites of T. gondii. At a safe concentration, BDQ displayed a dose-dependent inhibition on T. gondii growth with a half-maximal effective concentration (EC50) of 4.95 μM. Treatment with BDQ significantly suppressed the proliferation of T. gondii tachyzoites in the host cell, while the invasion ability of the parasite was not affected. BDQ incubation shrunk the mitochondrial structure and decreased the mitochondrial membrane potential and ATP level of T. gondii parasites. In addition, BDQ induced elevated ROS and led to autophagy in the parasite. By transcriptomic analysis, we found that oxidative phosphorylation pathway genes were significantly disturbed by BDQ-treated parasites. More importantly, BDQ significantly reduces brain cysts for the chronically infected mice. These results suggest that BDQ has potent anti-T. gondii activity and may impair its mitochondrial function by affecting proton transport. This study provides bedaquiline as a potential alternative drug for the treatment of toxoplasmosis, and our findings may facilitate the development of new effective drugs for the treatment of toxoplasmosis

Overexpression of OsABCG48 Lowers Cadmium in Rice (Oryza sativa L.)

Cadmium pollution threatens food safety and security by causing health issues and reducing farmland availability. Engineering genetic changes in crop plants to lower Cd accumulation can be a cost-effective approach to address this problem. Previously, we reported that a rice line, 2B, which expresses a truncated version of OsO3L2 had reduced Cd accumulation throughout the plant, including in seed. However, downstream events caused by expression of this gene were not known. In this study, RNA-seq was used to identify differentially expressed genes between the wild type and 2B rice with or without Cd treatment, leading to the study of an ABC transporter gene, OsABCG48 (ATP-Binding Cassette transporter G family member 48). Heterologous expression of OsABCG48 conferred tolerance to Cd in Schizosaccharomyces pombe, Arabidopsis and rice. Moreover, overexpressing OsABCG48 in rice lowered root Cd accumulation that was associated with more extensive lateral root development. These data suggest that OsABCG48 might have applications for engineering low-Cd rice

Elaboration of Ionic Liquids on the Anti-Wear Performance of the Reinforced Steel-Steel Contact Surface

This study conducted a tribological investigation of base oil (PAO6 and 5W 40) and ionic liquids (IL)-modified lubricants through a four-ball tribometer for 30 min. The lubricants were fabricated via a two-step method using stirring magnetic and ultrasonic dispersion. IL, base oil, and lubricants were, respectively, characterized by XRD and FTIR analysis. In addition, multiple characterizations such as EDS, 3D morphology, and SEM were carried out to evaluate the wear and friction performance of steel balls. Ultimately, the results showed that the coefficient of friction (COF) and wear scar diameter (WSD) of wear scar lubricated by IL-modified lubricants were greatly decreased than that by base oil. IL can well improve the tribological properties of PAO 6 oil and 5W-40 oil due to the tribo-film appearance on the friction surface of wear scar by the effective role of IL. Fascinatingly, this investigation comprehensively and elaborately put a new sight into the lubrication mechanism of how IL reacted with a base oil and enhanced the tribological characteristics

Effects of Salinity Stress on Histological Changes, Glucose Metabolism Index and Transcriptomic Profile in Freshwater Shrimp, <i>Macrobrachium nipponense</i>

Salinity is an important factor in the aquatic environment and affects the ion homeostasis and physiological activities of crustaceans. Macrobrachium nipponense is a shrimp that mainly lives in fresh and low-salt waters and plays a huge economic role in China’s shrimp market. Currently, there are only a few studies on the effects of salinity on M. nipponense. Therefore, it is of particular importance to study the molecular responses of M. nipponense to salinity fluctuations. In this study, M. nipponense was set at salinities of 0, 8, 14 and 22‰ for 6 weeks. The gills from the control (0‰) and isotonic groups (14‰) were used for RNA extraction and transcriptome analysis. In total, 593 differentially expressed genes (DEGs) were identified, of which 282 were up-regulated and 311 were down-regulated. The most abundant gill transcripts responding to different salinity levels based on GO classification were organelle membrane (cellular component), creatine transmembrane transporter activity (molecular function) and creatine transmembrane transport (biological function). KEGG analysis showed that the most enriched and significantly affected pathways included AMPK signaling, lysosome and cytochrome P450. In addition, 15 DEGs were selected for qRT-PCR verification, which were mainly related to ion homeostasis, glucose metabolism and lipid metabolism. The results showed that the expression patterns of these genes were similar to the high-throughput data. Compared with the control group, high salinity caused obvious injury to gill tissue, mainly manifested as contraction and relaxation of gill filament, cavity vacuolation and severe epithelial disintegration. Glucose-metabolism-related enzyme activities (e.g., pyruvate kinase, hexokinase, 6-phosphate fructose kinase) and related-gene expression (e.g., hexokinase, pyruvate kinase, 6-phosphate fructose kinase) in the gills were significantly higher at a salinity of 14‰. This study showed that salinity stress activated ion transport channels and promoted an up-regulated level of glucose metabolism. High salinity levels caused damage to the gill tissue of M. nipponense. Overall, these results improved our understanding of the salt tolerance mechanism of M. nipponense

Functional polythioamides derived from thiocarbonyl fluoride

Polythioamide is a unique type of sulfur-containing polymers with advanced functionalities. However, current synthetic approaches based on elemental sulfur, which could easily react with unsaturated functional groups, restrict the choice of substrates. Inspired by the highly efficient sulfur-fluoride exchange (SuFEx) polymerization through discrete hubs, we here report a novel and general method for the synthesis of polythioamides from diboronic acids, secondary diamines, and thiocarbonyl fluoride as the connective hub. Well-defined structures, including previously inaccessible unsaturated substrates, were realized. The polythioamides can efficiently and selectively bind to metal ions and were applied in precious metal recovery. Further development results in PdII-crosslinked single-chain nanoparticles acting as a recyclable homogeneous catalyst, demonstrating promising applications of these unprecedented polythioamides. We anticipate that thiocarbonyl fluoride could be a powerful hub for the challenging synthesis of sulfur-containing polymers

Synchronously Strengthen and Toughen Polypropylene Using Tartaric Acid-Modified Nano-CaCO3

In order to overcome the challenge of synchronously strengthening and toughening polypropylene (PP) with a low-cost and environmental technology, CaCO3 (CC) nanoparticles are modified by tartaric acid (TA), a kind of food-grade complexing agent, and used as nanofillers for the first time. The evaluation of mechanical performance showed that, with 20 wt.% TA-modified CC (TAMCC), the impact toughness and tensile strength of TAMCC/PP were 120% and 14% more than those of neat PP, respectively. Even with 50 wt.% TAMCC, the impact toughness and tensile strength of TAMCC/PP were still superior to those of neat PP, which is attributable to the improved compatibility and dispersion of TAMCC in a PP matrix, and the better fluidity of TAMCC/PP nanocomposite. The strengthening and toughening mechanism of TAMCC for PP involves interfacial debonding between nanofillers and PP, and the decreased crystallinity of PP, but without the formation of β-PP. This article presents a new applicable method to modify CC inorganic fillers with a green modifier and promote their dispersion in PP. The obtained PP nanocomposite simultaneously achieved enhanced mechanical strength and impact toughness even with high content of nanofillers, highlighting bright perspective in high-performance, economical, and eco-friendly polymer-inorganic nanocomposites