Ulam stability and data dependence for fractional differential equations with Caputo derivative

In this paper, Ulam stability and data dependence for fractional differential equations with Caputo fractional derivative of order $\alpha$ are studied. We present four types of Ulam stability results for the fractional differential equation in the case of $0<\alpha<1$ and $b=+\infty$ by virtue of the Henry-Gronwall inequality. Meanwhile, we give an interesting data dependence results for the fractional differential equation in the case of $1<\alpha<2$ and $b<+\infty$ by virtue of a generalized Henry-Gronwall inequality with mixed integral term. Finally, examples are given to illustrate our theory results

Distributed Random Reshuffling Methods with Improved Convergence

This paper proposes two distributed random reshuffling methods, namely Gradient Tracking with Random Reshuffling (GT-RR) and Exact Diffusion with Random Reshuffling (ED-RR), to solve the distributed optimization problem over a connected network, where a set of agents aim to minimize the average of their local cost functions. Both algorithms invoke random reshuffling (RR) update for each agent, inherit favorable characteristics of RR for minimizing smooth nonconvex objective functions, and improve the performance of previous distributed random reshuffling methods both theoretically and empirically. Specifically, both GT-RR and ED-RR achieve the convergence rate of $O(1/[(1-\lambda)^{1/3}m^{1/3}T^{2/3}])$ in driving the (minimum) expected squared norm of the gradient to zero, where $T$ denotes the number of epochs, $m$ is the sample size for each agent, and $1-\lambda$ represents the spectral gap of the mixing matrix. When the objective functions further satisfy the Polyak-{\L}ojasiewicz (PL) condition, we show GT-RR and ED-RR both achieve $O(1/[(1-\lambda)mT^2])$ convergence rate in terms of the averaged expected differences between the agents' function values and the global minimum value. Notably, both results are comparable to the convergence rates of centralized RR methods (up to constant factors depending on the network topology) and outperform those of previous distributed random reshuffling algorithms. Moreover, we support the theoretical findings with a set of numerical experiments.Comment: 16 pages, 8 figure

Retention in STEM: Factors Influencing Student Persistence and Employment

This study utilizes data from the Baccalaureate and Beyond Longitudinal Study to explore factors associated with the likelihood of students' employment in STEM fields one year after graduation. We examined various factors related to students' individual characteristics (e.g., gender, race, and financial situation), institutional experiences (e.g., major, academic standing, research involvement, internships, extracurricular activities, and undergraduate practicum), and institutional and national trends. The results indicate lower STEM employment likelihood for minority groups and students with academic probation. The findings also highlight the positive impact of undergraduate practicum and job relevance to major on STEM employment likelihood. On the contrary, career services were negatively associated with the likelihood of students' STEM occupation choice, suggesting potential shortcomings in STEM job preparation within these services. The study provides valuable insights and actionable recommendations for policymakers and educators seeking to increase diversity and inclusion in STEM fields, suggesting the need for more efficient and tailored educational interventions and curriculum development

DiffS2UT: A Semantic Preserving Diffusion Model for Textless Direct Speech-to-Speech Translation

While Diffusion Generative Models have achieved great success on image generation tasks, how to efficiently and effectively incorporate them into speech generation especially translation tasks remains a non-trivial problem. Specifically, due to the low information density of speech data, the transformed discrete speech unit sequence is much longer than the corresponding text transcription, posing significant challenges to existing auto-regressive models. Furthermore, it is not optimal to brutally apply discrete diffusion on the speech unit sequence while disregarding the continuous space structure, which will degrade the generation performance significantly. In this paper, we propose a novel diffusion model by applying the diffusion forward process in the \textit{continuous} speech representation space, while employing the diffusion backward process in the \textit{discrete} speech unit space. In this way, we preserve the semantic structure of the continuous speech representation space in the diffusion process and integrate the continuous and discrete diffusion models. We conduct extensive experiments on the textless direct speech-to-speech translation task, where the proposed method achieves comparable results to the computationally intensive auto-regressive baselines (500 steps on average) with significantly fewer decoding steps (50 steps).Comment: Accepted in EMNLP2023 main conferenc

Resistance practice on Chinese social media:Shifting to the “second half” of COVID-19 era

Previous studies on examining resistance practice online in China focus on the netizens’ response to breaking incidents and its potentials of challenging political power negotiation within social media sphere. This study explores the shifting effect on the strategic resistance practice in anaphase of COVID-19 pandemic, in which Chinese netizens shaped a unique combination of strategy-making and purposes under the persistent anti-pandemic policy, the ever-evolving censorship and the distraction released by government. Based on a qualitative discourse analysis of 2456 Weibo comments under three trending and distractive topics in April 2022, this study adopts the discursive pragmatic approach to reveal the major strategies utilised by netizens and their purposes of resistance in context. Within the current discourse, parody, teasing, and constructed utterances were identified as the major strategies, while a comparison with general Chinese online discourse shows that neology (novel words/expressions or existing words/expressions with new meanings) was dynamically and imaginatively applied by netizens for resistance. Further content analysis demonstrates that these strategies were served for combining personal experience, eye witnessing, sentiments and adaptations of latest memes with resistance as well as evasion of censorship, during which netizens with pragmatic competence of others’ outputs and the shared social-cultural background knowledge regarding pandemic events can achieve interactive and communicative exchange. Compared to existing Chinese social media discourse research literature during pandemic, this study exemplifies Chinese netizens shifted themselves from the cyber nationalism campaign during the “first half” to the “second half” of pandemic by rejecting deliberate distraction, focusing on their “mundane desires,” and showing little interests in leading collective political events online in everyday life with long-term anti-pandemic measures and up-to-date Internet surveillance. This shifting effect also enriches the description of liminal space in which the delay between netizen’s response, government supervision and censorship update under pandemic settings is different from the one shown in public incidents

Experimental study on influence of fault dip angle on acoustic emission sinal propagation

Natural rock mass is not a uniform continuum due to discontinuous interfaces such as faults and bedding planes between rock layers, and the propagation law of acoustic emission signals will inevitably change when they pass through faults and bedding planes. Therefore, studying the propagation law of acoustic emission signals in faults has become one of the key topics in rock mechanics. Based on the Huygens principle, the wave front equation under the condition of heterogeneous media containing faults was derived, and 45°, 60°, 75° and other types of fault specimens were made through laboratory similar simulation model tests. The acoustic emission signals across faults were monitored and recorded by combining ultrasonic tachymeter and DS5-16B full-information acoustic emission signal analyzer. Nonlinear fitting and numerical calculation of Matlab software are used to study the influence of faults and the number of bedding planes of different inclination angles on the propagation speed and signal characteristics of acoustic emission signals. The results show that the propagation speed of acoustic emission signals increases gradually with the increase of fault dip angle, and the propagation speed is positively correlated with fault dip angle. The larger the fault dip angle is, the faster the signal propagation speed will be, and the propagation speed will attenuate after the signal passes through the fault, and the larger the fault dip angle is, the smaller the proportion of velocity attenuation will be. The propagation velocity is attenuated by the bedding plane, and the single bedding plane has little influence on the velocity, while the two bedding planes have great influence on the velocity. The fault will make the maximum value of the signal decrease, the main frequency decrease, and the frequency interval move to the low frequency direction. The larger the fault inclination, the larger the maximum value, the main frequency and the frequency interval. One layer has little influence on the signal, which is basically the same as the time-frequency characteristics of the signal without stratification, while the two layers have a greater influence on the signal, which will greatly reduce the maximum value, main frequency and frequency interval of the signal. The existence of fault will cause the instantaneous energy of acoustic emission signal to decrease greatly, and the smaller the inclination angle, the more serious the attenuation is. The research results can provide theoretical basis for the establishment of wave velocity model under the ray theory

Cancer-Associated Fibroblasts Build and Secure the Tumor Microenvironment

Tumor cells reside in a highly complex and heterogeneous tumor microenvironment (TME), which is composed of a myriad of genetically stable non-cancer cells, including fibroblasts, immune cells, endothelial cells, and epithelial cells, and a tumor-specific extracellular matrix (ECM). Cancer-associated fibroblasts (CAFs), as an abundant and active stromal cell population in the TME, function as the signaling center and remodeling machine to aid the creation of a desmoplastic tumor niche. Although there is no denial that the TME and CAFs may have anti-tumor effects as well, a great deal of findings reported in recent years have convincingly revealed the tumor-promoting effects of CAFs and CAF-derived ECM proteins, enzymes, chemical factors and other downstream effectors. While there is growing enthusiasm for the development of CAF-targeting therapies, a better understanding of the complexities of CAF-ECM and CAF-cancer cell interactions is necessary before novel therapeutic strategies targeting the malignant tumor “soil” can be successfully implemented in the clinic

Linkage Mapping of Stem Saccharification Digestibility in Rice

Rice is the staple food of almost half of the world population, and in excess 90% of it is grown and consumed in Asia, but the disposal of rice straw poses a problem for farmers, who often burn it in the fields, causing health and environmental problems. However, with increased focus on the development of sustainable biofuel production, rice straw has been recognized as a potential feedstock for non-food derived biofuel production. Currently, the commercial realization of rice as a biofuel feedstock is constrained by the high cost of industrial saccharification processes needed to release sugar for fermentation. This study is focused on the alteration of lignin content, and cell wall chemotypes and structures, and their effects on the saccharification potential of rice lignocellulosic biomass. A recombinant inbred lines (RILs) population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 271 molecular markers for quantitative trait SNP (QTS) analyses was used. After association analysis of 271 markers for saccharification potential, 1 locus and 4 pairs of epistatic loci were found to contribute to the enzymatic digestibility phenotype, and an inverse relationship between reducing sugar and lignin content in these recombinant inbred lines was identified. As a result of QTS analyses, several cell-wall associated candidate genes are proposed that may be useful for marker-assisted breeding and may aid breeders to produce potential high saccharification rice varieties

Real-world TRAE association between niraparib and platinum-based chemotherapy

BackgroundPre-clinical studies showed the anti-tumor mechanisms of PARP inhibitors (PARPi) and platinum have some crossover and overlap in the DNA damage repair pathway, patients who respond to platinum-based chemotherapy are also more likely to be sensitive to PARPi. This real-world study mainly aimed to evaluate whether TRAE (treatment-related adverse event) between platinum based chemotherapy (PBC) and niraparib are also associated.MethodsPatients received niraparib as maintenance treatment or salvage therapy for advanced ovarian cancer at the First Affiliated Hospital of Gannan Medical University from January 2020 to August 2023 were included. Survival data of niraparib treatment and adverse events occurred during the last platinum-based chemotherapy cycle before starting niraparib treatment and during niraparib treatment are documented. Fisher’s exact test were used for correlation analysis.Results1. 40 patients treated with niraparib were included in the analysis, including 31 patients treated with niraparib for 1st-line maintenance therapy, 6 patients for PSR (platinum-sensitive recurrence) maintenance therapy, and 3 patients for salvage therapy. The overall median follow-up time was 15.0 months (ranged from 2.2 months to 32.1 months). 2. Overall grade≥3 TRAE (40% vs 70%, p=0.012) including anemia (20% vs 45%, p=0.041) and neutrophil count decreased (17.5% vs 57.5%, p&lt;0.001) was significantly lower during niraparib treatment compared to during chemotherapy. 3. Any grade TRAE (75% vs 100%, p=0.002) including white blood cell count decreased (47.5% vs 87.5%, p&lt;0.001), red blood cell count decreased (57.5% vs 92.5%, p&lt;0.001), anemia (55% vs 87.5%, p&lt;0.001) and neutrophil count decreased (35% vs 85%, p&lt;0.001) were also significantly lower in niraparib treatment group compared with chemotherapy group. No new safety signals were identified.Conclusion1. In this real-world practice, we observed that patients with advanced ovarian cancer who experienced any grade and grade ≥3 TRAE during chemotherapy were well tolerated when treated with niraparib, particularly the incidence of any grade and grade ≥3 anemia, and neutrophil count decreased during niraparib treatment were significantly lower compared with that during chemotherapy. 2. For patients with ovarian cancer who have experienced grade ≥3 hematological adverse reactions during prior platinum-based chemotherapy, greater attention should be paid to the monitoring and management of hematological adverse reactions during subsequent treatment with niraparib