Dynamics of a Stage-Structured Leslie-Gower Predator-Prey Model

A generalized version of the Leslie-Gower predator-prey model that incorporates the prey population structure is introduced. Our results show that the inclusion of (age) structure in the prey population does not alter the qualitative dynamics of the model; that is, we identify sufficient conditions for the ‘‘trapping’’ of the dynamics in a biological compact set—albeit the analysis is a bit more challenging. The focus is on the study of the boundedness of solutions and identification of sufficient conditions for permanence. Sufficient conditions for the local stability of the nonnegative equilibria of the model are also derived, and sufficient conditions for the global attractivity of positive equilibrium are obtained. Numerical simulations are used to illustrate our results

Promoting public skin health through a national continuing medical education project on cosmetic and dermatologic sciences: a 15-year experience

BackgroundThe developments in cosmetic sciences and technologies have generated a gap between the cosmetics and their users. Users including regular customers, clinicians, industry personnel, researchers, testing agencies, beauty salon workers, and mass media hardly possess the ability to distinguish truth from falsehood. The gap remained as one major reason for inappropriate cosmetics usage, insufficient efficacy, and even cosmetics adverse reactions (CARs).MethodsAiming at enhancing the relevant practitioners’ cosmetic and dermatologic sciences, we launched a cosmetic and dermatologic sciences continuing medical education (CME) since 2008. The objective of the current study was to evaluate the effectiveness of the CME. We summarized and analyzed the project for the last 15 years. Meanwhile, an online survey consisted of three parts was performed to evaluate the CME and to collect the trainees’ comments.ResultsA total of 3,923 trainees have participated in the CME project from 2008 to 2022. The trainees included clinicians, industry staffs, biomedical researchers, third-party cosmetics testing staffs, beauty salon staffs, students, and media staffs. The trainees had theory courses on cosmetic and dermatologic sciences, cosmetics DIY practice & video watching, and an optional guided tour during the 4.5-day CME. Eight hundred and twenty-three trainees and 586 control subjects responded to the online survey. The comprehensive test in the second part of the survey demonstrated that compared with the control group, the CME project significantly enhanced the trainees’ perception and knowledge regarding the cosmetics formula sciences, basic dermatologic sciences, cosmetics usage, noninvasive measurements, new advances, CARs, and laws (p = 0.000). Trainees of all occupations ranked “basic dermatologic sciences and skin diseases” as the most significant sections. Trainees of all occupations believed the CME has contributed most in “understand the function & efficacy of cosmetics.” We noticed the occupational variances. Over 97% of trainees were willing to recommend the CME to the others.ConclusionThe CME project significantly enhanced the trainees’ cosmetic and dermatologic sciences, which bridged the gap between cosmetics and public skin health. This multidisciplinary CME also contributed to establishing an interdisciplinary interaction and cooperation platform for the multiple occupations involved in the public skin health maintenance and promotion

Early-stage effect of HIBD on neuro-motor function and organic composition of neurovascular units in neonatal rats

ObjectiveThis study aimed to investigate the effects of neonatal hypoxic–ischemic brain damage (HIBD) on early-stage neuro-motor function, cerebral blood flow, and the neurovascular unit.MethodsTwenty-four Sprague–Dawley newborn rats aged 7 days were obtained and randomly assigned to either the sham or the model group using a random number table. The HIBD model was established using the Rice-Vannucci method. After the induction of HIBD, the body weight of the rats was measured and their neuro-motor function was assessed. Further, cerebral blood flow perfusion was evaluated using laser speckle flow imaging, and immunofluorescent staining techniques were employed for examining the activation of specific markers and their morphological changes in different cell populations, which included vascular endothelial cells, neurons, astrocytes, and microglia within the motor cortex.ResultsAfter HIBD, the model group exhibited impaired neuro-motor function and growth. Cerebral blood flow perfusion decreased in both the hemispheres on day 1 and in the ipsilateral brain on day 4. However, no significant difference was observed between the two groups on day 7. Moreover, the CD31 and NeuN showed a sharp decline on day 1, which was followed by a gradual increase in the expression levels. The activated microglia and astrocytes formed clusters in the injured cortex. Notably, the regions with positive staining for Arg-1, Iba-1, CD68, and GFAP consistently displayed higher values in the model group as compared to that in the sham group. The total number of branch endpoints and microglia branches was higher in the model group than in the sham group. Immunofluorescent co-localization analysis revealed no co-staining between Iba-1 and Arg-1; however, the Pearson’s R-value for the co-localization of Iba-1 and CD68 was higher in the model group, which indicated an increasing trend of co-staining in the model group.ConclusionEarly-stage neuro-motor function, cerebral blood flow, microvasculature, and neurons in neonatal rats exhibited a trend of gradual recovery over time. The activation and upregulation of neuroglial cells continued persistently after HIBD. Furthermore, the impact of HIBD on early-stage neuro-motor function in newborn rats did not synchronize with the activation of neuroglial cells. The recovery of neuro-motor function, microvasculature, and neurons occurred earlier than that of neuroglial cells

平成18年度学位論文要旨・論文審査要旨

日本におけるストック・オプション制度 : その経済的効果を中心として[霍]環境事故と賠償責任ルールの経済分析[後藤]不完備契約理論と法の経済学[佐藤]遺伝的プログラミングによるエージェント行動分析と動的システム解析の研究[呂]1920-1945年中国東北部の綿業 : 奉天市の綿織物業を中心として[張]Economic Analyses of Energy Efficiency, CO2 Emissions and Income in the Context of Climate Change Mitigation（気候変動対策に関連したエネルギー効率、CO2排出、所得の経済分析）[Generosa]ネットワーク効果の経済分析 : 航空市場を中心として[川崎

Aggregation tests identify new gene associations with breast cancer in populations with diverse ancestry

Low-frequency variants play an important role in breast cancer (BC) susceptibility. Gene-based methods can increase power by combining multiple variants in the same gene and help identify target genes. We evaluated the potential of gene-based aggregation in the Breast Cancer Association Consortium cohorts including 83,471 cases and 59,199 controls. Low-frequency variants were aggregated for individual genes' coding and regulatory regions. Association results in European ancestry samples were compared to single-marker association results in the same cohort. Gene-based associations were also combined in meta-analysis across individuals with European, Asian, African, and Latin American and Hispanic ancestry. In European ancestry samples, 14 genes were significantly associated (q < 0.05) with BC. Of those, two genes, FMNL3 (P = 6.11 × 10 ) and AC058822.1 (P = 1.47 × 10 ), represent new associations. High FMNL3 expression has previously been linked to poor prognosis in several other cancers. Meta-analysis of samples with diverse ancestry discovered further associations including established candidate genes ESR1 and CBLB. Furthermore, literature review and database query found further support for a biologically plausible link with cancer for genes CBLB, FMNL3, FGFR2, LSP1, MAP3K1, and SRGAP2C. Using extended gene-based aggregation tests including coding and regulatory variation, we report identification of plausible target genes for previously identified single-marker associations with BC as well as the discovery of novel genes implicated in BC development. Including multi ancestral cohorts in this study enabled the identification of otherwise missed disease associations as ESR1 (P = 1.31 × 10 ), demonstrating the importance of diversifying study cohorts. [Abstract copyright: © 2023. The Author(s).

Prediction of chemical reaction yields with large-scale multi-view pre-training

Abstract Developing machine learning models with high generalization capability for predicting chemical reaction yields is of significant interest and importance. The efficacy of such models depends heavily on the representation of chemical reactions, which has commonly been learned from SMILES or graphs of molecules using deep neural networks. However, the progression of chemical reactions is inherently determined by the molecular 3D geometric properties, which have been recently highlighted as crucial features in accurately predicting molecular properties and chemical reactions. Additionally, large-scale pre-training has been shown to be essential in enhancing the generalization capability of complex deep learning models. Based on these considerations, we propose the Reaction Multi-View Pre-training (ReaMVP) framework, which leverages self-supervised learning techniques and a two-stage pre-training strategy to predict chemical reaction yields. By incorporating multi-view learning with 3D geometric information, ReaMVP achieves state-of-the-art performance on two benchmark datasets. Notably, the experimental results indicate that ReaMVP has a significant advantage in predicting out-of-sample data, suggesting an enhanced generalization ability to predict new reactions. Scientific Contribution: This study presents the ReaMVP framework, which improves the generalization capability of machine learning models for predicting chemical reaction yields. By integrating sequential and geometric views and leveraging self-supervised learning techniques with a two-stage pre-training strategy, ReaMVP achieves state-of-the-art performance on benchmark datasets. The framework demonstrates superior predictive ability for out-of-sample data and enhances the prediction of new reactions

Application of the Generalized Bessel Function to Two-Color Phase-of-the-Phase Spectroscopy

In two-color strong field ionization of atoms, dynamical characteristics such as ionization rate and electron trajectory depend heavily on the relative phase of the strong fundamental field and its second harmonic. The phase-of-the-phase spectroscopy method reveals the oscillation of the photoelectron momentum distribution with the relative phase of the two-color field, and the relative phase contrast and its phase are usually obtained by the fitting process. Instead, we apply the generalized Bessel function to the strong field approximation and derive analytical expressions for the first- and second-order relative phase contrast and phase-of-the-phase spectra. Our analytical results are in good agreement with fitting-based ones, but calculating them is much less computationally intensive. We illustrate the advantage of using generalized Bessel functions in two-color phase-of-the-phase spectroscopy of argon

Growth and feeding habits of invasive Pseudorasbora parva in the Chabalang Wetland (Lhasa, China) and its trophic impacts on native fish

In recent years, fish invasion has become one of the main reasons for the decline of native fish stocks. Pseudorasbora parva is considered one of the major invasive species worldwide. The present study investigated the fish resources of the Chabalang Wetland (Lhasa, Tibet) during different seasons in 2009 and 2013. Four hundred and twelve individuals were subsampled to estimate age, growth, and feeding habit of P. parva. Furthermore, food relationships between P. parva and the native Schizothoracinae fish were also examined. The results revealed a significant shift in species composition and community structure characterized by the disappearance of native fish and outbreak of non-native fish. The percentage of nonnative P. parva in the fish collections significantly increased from 33.64% in 2009 to 64.08% in 2013. The standard length (SL) ranged from 22.00 to 78.71 mm, and their age was 1-5 yr. The von Bertalanffy function was used to model the observed length-at-age data as L-t =112.19(1-e(-0.1495 ( t +0.8012)) ) for females and as L-t =123.12 (1-e(-0.1500 ( t +0.7132))) for males. The results indicated that P. parva in Tibet has lower growth and mortality rates compared with that from the native ranges. Ninety-seven prey taxa belonging to 9 prey categories were identified in the gut of 38 P. parva. P. parva can be considered a generalized and opportunistic predator, competing with the native fish, especially Schizothorax o'connori, Schizopygopsis younghusbandi younghusbandi, and Ptychobarbus dipogon, for Bacillariophyta and Chironomid larvae. This is an important reason for the decline in native fish population

Nanocrystallization of Anthocyanin Extract from Red-Fleshed Apple ′QN-5′ Improved Its Antioxidant Effect through Enhanced Stability and Activity under Stressful Conditions

Red-flesh apples are known as functional fruits because of their rich anthocyanin. The anthocyanin content of the red flesh apple cultivar &#8242;QN-5&#8242; we bred can reach 361 mg&#183;kg&#8722;1 (FW), and showed higher scavenging capacity to DPPH radicals, hydroxyl radicals, and superoxide anion radicals, with scavenging rates of 80.0%, 54.0%, and 43.3%, respectively. We used this particular anthocyanin-rich &#8242;QN-5&#8242; apple as material to examine how nanocrystallization affects the antixodiant effect of anthocyanin. The anthocyanin extract was encapsulated with biocompatible zein to form zein-anthocyanin nanoparticles (ZANPs). Transmission electron microscopy (TEM) scanning showed that ZANPs had a regular spherical shape with an average diameter size of 50&#8211;60nm. When the ratio of the zein and the anthocyanin was 1:0.5, the results suggested that the encapsulation efficiency (EE) of the ZANPs could reach as high as 92.8%, and that scavenging rate for DPPH radicals was increased from 87.1% to 97.2% compared to the non-nanocrystallized anthocyanin extract. Interestingly, treatment under alkaline conditions (pH 9.0), high temperature (90 &#176;C), and a storage time of 7 days could decrease the scavenging capacity of the ZANPs for DPPH radicals, but this scavenging capacity loss for ZANPs was significantly lower than that observed in the non-nanocrystallized anthocyanin, suggesting the higher stability of ZANPs is caused by encapsulation. These results would provide a theoretical basis for the application of the anthocyanin in scavenging free radicals under stress conditions