Search

Abstract Eels migrate along largely unknown routes to their spawning ground. By coupling Zermelo’s navigation solution and data from the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2M), we simulated a range of seasonal scenarios, swimming speeds, and swimming depths to predict paths that minimize migration duration and energy cost. Our simulations predict a trade-off between migration duration and energy cost. Given that eels do not refuel during their migration, our simulations suggest eels should travel at speeds of 0.4–0.6 body-length per second to retain enough energy reserves for reproduction. For real eels without full information of the ocean currents, they cannot optimize their migration in strong surface currents, thus when swimming at slow swimming speeds, they should swim at depths of 200 m or greater. Eels swimming near the surface are also influenced by seasonal factors, however, migrating at greater depths mitigates these effects. While greater depths present more favorable flow conditions, water temperature may become increasingly unfavorable, dropping near or below 5 °C. Our results serve as a benchmark, demonstrating the complex interplay between swimming speed, depth, seasonal factors, migration time, and energy consumption, to comprehend the migratory behaviors of Japanese eels and other migratory fish.

Co-creativity focuses on how individuals produce innovative ideas together. As few studies have explored co-creativity using standardized tests, it is difficult to effectively assess the individual’s creativity performance within a group. Therefore, this study aims to develop a platform that allows two individuals to answer creativity tests simultaneously. This platform includes two divergent thinking tasks, the Straw Alternative Uses Test and Bottle Alternative Uses Test, and Chinese Radical Remote Associates Test A and B, which were used to evaluate their open-and closed-ended creative problem-solving performance. This platform has two modes: single-player mode and paired-player mode. Responses from 497 adults were collected, based on which the fluency, flexibility, and originality of divergent thinking were measured. This study also developed a computer scoring technique that can automatically calculate the scores on these creativity tests. The results showed that divergent thinking scores from computer-based calculation and manual scoring were highly positively correlated, suggesting that the scores on a divergent thinking task can be calculated through a system that avoids time-consuming, uneconomical manual scoring. Overall, the two types of tests on this platform showed considerable internal consistency reliability and criterion-related validity. This advanced application facilitates the collection of empirical evidence about co-creativity.

Creativity has been one of the focuses of educational research. The Remote Associates Test (RAT) is a valid measurement to evaluate the effect of creativity training. Because of its objective scoring, short completion time required, and relatively simple question preparation, RAT has been adopted in Chinese creativity research for almost 20 years. This study integrates the literature and is divided into four parts: development and comparison of different versions, the exploration of the problem-solving process, factors related to remote association, and effectiveness of different interventions. The results show that the Chinese version of RAT was developed in three levels: radical, character, and word. Behavioral and neuroscience research indicates that the problem-solving process must be dynamic and flexible, and that manipulating internal or external influences can improve associative ability. Suggestions for teaching practices include assessing students’ creativity with the RAT, creating a safe environment, training divergent and convergent thinking, and thinking outside the box. The present study provides a comprehensive framework for the development and application of the Chinese versions of the RAT, methods to evaluate students’ creativity, and proposes a scope for future research to examine creativity theory.

The reduction in government support and the rapid growth in the number of nonprofit organizations have made them face fierce competition for charitable donations. Identifying valuable donors and developing effective marketing strategies can contribute to online donation platforms. This study explored online donors’ characteristics in Taiwan through the identification of different donor segments using a refined clustering algorithm. Furthermore, the marketing strategies based on the salient features of each segment are offered to retain donors and maximize their monetary donations. A real dataset derived from 14,029 donation records contributed by 7,432 donors during the years of 2016–2018 on an online donation platform were collected. A refined cluster analysis based on an improved particle swarm optimization algorithm was applied according to RFM (Recency, Frequency, and Monetary) values and donors’ socio-demographic variables (e.g., Sex, Age, and Education). The results offered four segments of online donors in Taiwan. “Passive donors” were found to be the largest segment (38%), followed by “female active donors” (24%), “potential donors” (21%), and “male loyal donors” (17%). Most donors on the platform were female, highly educated, and aged between 30 and 40. The men’s single donation amount was higher than women’s; however, the women’s total donations were higher than men’s. We contributed the donor segmentation process with a refined clustering technique, which combines RFM and socio-demographic variables as criteria to compensate for the shortcomings of previous studies that only focused on RFM. Longitudinal online donation data instead of the questionnaire survey was used to analyze the profiles of online charitable donors in Taiwan.

The goal of this paper is to investigate the curves intersected by a vertical plane with the surfaces based on certain NCP functions. The convexity and differentiability of these curves are studied as well. In most cases, the inflection points of the curves cannot be expressed exactly. Therefore, we instead estimate the interval where the curves are convex under this situation. Then, with the help of differentiability and convexity, we obtain the local minimum or maximum of the curves accordingly. The study of these curves is very useful to binary quadratic programming.

This case is a 78-year-old woman with hypertension, diabetes mellitus, cardiovascular disease, valvular heart failure and hepatitis C. She presented to outpatient department for her right breast lump. The pathology of the core biopsy under breast sonography showed carcinoma with neuroendocrine features. Its immunohistochemical study showed negative for estrogen receptor (ER), progesterone Receptor (PR), HER2/neu and GATA-3, and positive for chromogranin A, synaptophysin, and TTF-1. A staging workup was then performed. The computed tomography (CT) of chest and abdomen revealed another mass in the left lung. CT-guided biopsy was done for the lung mass. According to the results of immunostains, a primary lung large cell neuroendocrine carcinoma (LCNEC) with breast metastasis was diagnosed. The patient received chemotherapy with etoposide and carboplatin for 6 cycles. The CT performed 3 and 5 months later showed that the response of the tumors was stable.

In this study, n-type gallium nitride (GaN) films were fabricated by a silicon–titanium (Si-Ti) codoping sputtering technique with a zinc oxide (ZnO) buffer layer on amorphous glass substrates with different post-growth annealing temperatures for optimizing the GaN crystal quality. Si-Ti-codoped n-type GaN films that were thermally annealed at 400 °C had a low thin-film resistivity of 2.6 × 10−1 Ω-cm and a high electron concentration of 6.65 × 1019 cm−3, as determined through Hall measurement. X-ray diffraction (XRD) results revealed a high (002) XRD intensity with a narrow spectral line and a full width at half maximum (FWHM) value that indicated the superior crystal growth of a hexagonal structure of the GaN thin films. In addition, photoluminescence measurement results demonstrated a near-band-edge emission at 365 nm, indicating the crystal growth of GaN thin films on glass substrates. The Burstein–Moss effect was observed in the Tauc plot results, indicating that the Fermi level inside the conduction band moves upward and thus improves the n-type properties of the GaN thin film. X-ray photoelectron spectroscopy measurement results revealed that all atoms doped into the GaN film are present and that both Si and Ti atoms bond with N atoms.

In this study, we explore the dynamical role of mesoscale eddies on fish larvae migration using the example of Subtropical Counter Current eddies and the migration of Japanese eel larvae in the western North Pacific Ocean. An idealized experiment is conducted to isolate the effects of eddies, and use a three-dimensional particle-tracking method to simulate virtual eel larvae (v-larvae) migration, including both horizontal and vertical swimming behaviors. The impact of eddies strongly depends on the swimming speed of v-larvae relative to the eddy speed. Eddies accelerate the movement of v-larvae that swim slower than the propagation speed of the eddy, whereas faster-swimming v-larvae are dragged by eddies. A modified stream function that incorporates biological swimming ability explains the non-uniform trapping of v-larvae in mesoscale eddies. A high swimming speed and/or a small eddy rotation speed results in a weak trapping capacity. Simulations of v-larvae migration in realistic cases of eddy fields indicate that the abundance of eddies significantly affects the duration of larval migration, with the effects being largely dependent on the larvae swimming speed. We noted a negative relationship between the observed annual eel recruitment index in Taiwan and the eddy index subtropical countercurrent (STCC) region, which suggests a potentially important role of mesoscale eddies in eel larvae migration.

Synchronized bursts (SBs) with complex structures are common in neuronal cultures. Although the phenomenon of SBs has been discovered for a long time, its origin is still unclear. Here, we investigate the properties of these SBs in cultures grown on a multi-electrode array. We find that structures of these SBs are related to the different developmental stages of the cultures and these structures can be modified by changing the magnesium concentration in the culture medium; indicating that synaptic mechanism is involved in the generation of SBs. A model based on short term synaptic plasticity (STSP), recurrent connections and astrocytic recycling of neurotransmitters has been developed successfully to understand the observed structures of SBs in experiments. A phase diagram obtained from this model shows that networks exhibiting SBs are in a complex oscillatory state due to large enough positive feedback provided by synaptic facilitation and recurrent connections. In this model, while STSP controls the fast oscillations (∼ 100 ms) within a SB, the astrocytic recycling determines the slow time scale (∼10 s) of inter-burst intervals. Our study suggests that glia-neuron interactions can be important in the understanding of the complex dynamics of neuronal networks.

The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels) were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2). Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading), orientation toward the spawning area (fixed heading), and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season). The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC), the Kuroshio, and the Subtropical Countercurrent (STCC) region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO). This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D) particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2). Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels") can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

A data-assimilated Taiwan Ocean Prediction (ATOP) system is being developed at the National Central University, Taiwan. The model simulates sea-surface height, three-dimensional currents, temperature and salinity and turbulent mixing. The model has options for tracer and particle-tracking algorithms, as well as for wave-induced Stokes drift and wave-enhanced mixing and bottom drag. Two different forecast domains have been tested: a large-grid domain that encompasses the entire North Pacific Ocean at 0.1° × 0.1° horizontal resolution and 41 vertical sigma levels, and a smaller western North Pacific domain which at present also has the same horizontal resolution. In both domains, 25-year spin-up runs from 1988 - 2011 were first conducted, forced by six-hourly Cross-Calibrated Multi-Platform (CCMP) and NCEP reanalysis Global Forecast System (GSF) winds. The results are then used as initial conditions to conduct ocean analyses from January 2012 through February 2012, when updated hindcasts and real-time forecasts begin using the GFS winds. This paper describes the ATOP system and compares the forecast results against satellite altimetry data for assessing model skills. The model results are also shown to compare well with observations of (i) the Kuroshio intrusion in the northern South China Sea, and (ii) subtropical counter current. Review and comparison with other models in the literature of ¡§(i)¡¨ are also given.