Understanding the in vivo Uptake Kinetics of a Phosphatidylethanolamine-binding Agent \u3csup\u3e99m\u3c/sup\u3eTc-Duramycin

Introduction 99mTc-Duramycin is a peptide-based molecular probe that binds specifically to phosphatidylethanolamine (PE). The goal was to characterize the kinetics of molecular interactions between 99mTc-Duramycin and the target tissue. Methods High level of accessible PE is induced in cardiac tissues by myocardial ischemia (30 min) and reperfusion (120 min) in Sprague–Dawley rats. Target binding and biodistribution of 99mTc-duramycin were captured using SPECT/CT. To quantify the binding kinetics, the presence of radioactivity in ischemic versus normal cardiac tissues was measured by gamma counting at 3, 10, 20, 60 and 180 min after injection. A partially inactivated form of 99mTc-Duramycin was analyzed in the same fashion. A compartment model was developed to quantify the uptake kinetics of 99mTc-Duramycin in normal and ischemic myocardial tissue. Results 99mTc-duramycin binds avidly to the damaged tissue with a high target-to-background radio. Compartment modeling shows that accessibility of binding sites in myocardial tissue to 99mTc-Duramycin is not a limiting factor and the rate constant of target binding in the target tissue is at 2.2 ml/nmol/min/g. The number of available binding sites for 99mTc-Duramycin in ischemic myocardium was estimated at 0.14 nmol/g. Covalent modification of D15 resulted in a 9-fold reduction in binding affinity. Conclusion 99mTc-Duramycin accumulates avidly in target tissues in a PE-dependent fashion. Model results reflect an efficient uptake mechanism, consistent with the low molecular weight of the radiopharmaceutical and the relatively high density of available binding sites. These data help better define the imaging utilities of 99mTc-Duramycin as a novel PE-binding agent

IC 225: a dwarf elliptical galaxy with a peculiar blue core

We present the discovery of a peculiar blue core in the elliptical galaxy IC 225 by using images and spectrum from the Sloan Digital Sky Survey (SDSS). The outer parts of the surface brightness profiles of u-, g-, r-, i- and z-band SDSS images for IC 225 are well fitted with an exponential function. The fitting results show that IC 225 follows the same relations between the magnitude, scale length and central surface brightness for dwarf elliptical galaxies. Its absolute blue magnitude (M_B) is -17.14 mag, all of which suggest that IC 225 is a typical dwarf elliptical galaxy. The g-r color profile indicates a very blue core with a radius of 2 arcseconds, which is also clearly seen in the RGB image made of g-, r- and i-band SDSS images. The SDSS optical spectrum exhibits strong and very narrow nebular emission lines. The metal abundances derived by the standard methods, which are 12+log(O/H) = 8.98, log(N/O) = -0.77 and 12+log(S+/H+) = 6.76, turn out to be significantly higher than that predicted by the well-known luminosity-metallicity relation. After carefully inspecting the central region of IC 225, we find that there are two distinct nuclei, separated by 1.4 arcseconds, the off-nucleated one is even bluer than the nucleus of IC 225. The asymmetric line profiles of higher-order Balmer lines indicate that the emission lines are bluer shifted relative to the absorption lines, suggesting that the line emission arises from the off-center core, whose nature is a metal-rich Hii region. To the best of our knowledge, it is the first high-metallicity Hii region detected in a dwarf elliptical galaxy.Comment: 7 figures, accepted for publication in A

Evaluating the Perceived Safety of Urban City via Maximum Entropy Deep Inverse Reinforcement Learning

Inspired by expert evaluation policy for urban perception, we proposed a novel inverse reinforcement learning (IRL) based framework for predicting urban safety and recovering the corresponding reward function. We also presented a scalable state representation method to model the prediction problem as a Markov decision process (MDP) and use reinforcement learning (RL) to solve the problem. Additionally, we built a dataset called SmallCity based on the crowdsourcing method to conduct the research. As far as we know, this is the first time the IRL approach has been introduced to the urban safety perception and planning field to help experts quantitatively analyze perceptual features. Our results showed that IRL has promising prospects in this field. We will later open-source the crowdsourcing data collection site and the model proposed in this paper.Comment: ACML2022 Camera-ready Versio

Exploring How Tourism Majors’ Perceived Professional Competence Influences Their Choice of Tourism Careers in China

With the rapid development of tourism in China, various economic sectors such as agriculture, sports, food and beverages, cultural heritage, and outdoor adventure have become integrated into the tourism industry. China\u27s tourism industry has changed and these changes now require tourism practitioners to adapt. Chinese universities must also adapt their tourism curriculum and educational practices to reflect changes in the tourism sector. Research suggests that university training programs should increase their emphasis on developing students’ professional competency and expand the range of competencies they address in their curriculum. At the same time, tourism enterprises in China are unable to recruit enough competent employees, resulting in a shortage of qualified workers. To improve the professional competence of tourism students in China, tourism education departments must respond to the needs of, and changes in, the tourism industry. The purpose of this two-phase, mixed-method exploratory design study is to identify the professional competencies that tourism experts in China believe tourism students must acquire, and examine the relationship between these competencies, tourism students’ perceptions of professional competence, and their intent to pursue a career in the tourism sector. The present study began with basic qualitative research in the form of interviews with Chinese tourism experts in China to identify the professional competencies that Chinese tourism students need. During the second stage of research, these results were incorporated into a written questionnaire that was distributed to approximately 800 tourism majors in China. Through the analysis of survey data, we examined the relationship between student demographics, their perceived professional competence, and their intent to pursue a career in the tourism sector. The study results indicate that the causal relationship between students\u27 perceived professional competence and students\u27 intention for a career in tourism is valid. These findings provide theoretical support for improving tourism students\u27 perceived professional competency. The results also suggest strategies to increase the percentage of tourism students who will choose to work in the tourism sector upon graduation

Project Evaluation and Selection with Task Failures

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154433/1/poms13107_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154433/2/poms13107.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154433/3/poms13107-sup-0001-Appendix.pd

The K-band properties of Seyfert 2 galaxies

It is well known that the [O {\sc iii}]$\lambda$5007 emission line and hard X-ray(2-10keV) luminosities are good indicators of AGN activities and that the near and mid-infrared emission of AGN originates from re-radiation of dusty clouds heated by the UV/optical radiation from the accretion disk. In this paper we present a study of the near-infrared K-band (2.2$\mu$m) properties for a sample of 65 Seyfert 2 galaxies. By using the AGN/Bulge/Disk decomposition technique, we analyzed the 2MASS K$_{\rm S}$-band images for Seyfert 2 galaxies in order to derive the K$_{\rm S}$- band magnitudes for the central engine, bulge, and disk components. We find that the K$_{\rm S}$-band magnitudes of the central AGN component in Seyfert 2 galaxies are tightly correlated with the [O {\sc iii}]$\lambda$5007 and the hard X-ray luminosities, which suggests that the AGN K-band emission is also an excellent indicator of the nuclear activities at least for Seyfert 2 galaxies. We also confirm the good relation between the central black hole masses and bulge's K-band magnitudes for Seyfert 2s.Comment: 7 pages, 4 figures, accepted for publication in A&

The New Agronomists: Language Models are Experts in Crop Management

Crop management plays a crucial role in determining crop yield, economic profitability, and environmental sustainability. Despite the availability of management guidelines, optimizing these practices remains a complex and multifaceted challenge. In response, previous studies have explored using reinforcement learning with crop simulators, typically employing simple neural-network-based reinforcement learning (RL) agents. Building on this foundation, this paper introduces a more advanced intelligent crop management system. This system uniquely combines RL, a language model (LM), and crop simulations facilitated by the Decision Support System for Agrotechnology Transfer (DSSAT). We utilize deep RL, specifically a deep Q-network, to train management policies that process numerous state variables from the simulator as observations. A novel aspect of our approach is the conversion of these state variables into more informative language, facilitating the language model's capacity to understand states and explore optimal management practices. The empirical results reveal that the LM exhibits superior learning capabilities. Through simulation experiments with maize crops in Florida (US) and Zaragoza (Spain), the LM not only achieves state-of-the-art performance under various evaluation metrics but also demonstrates a remarkable improvement of over 49\% in economic profit, coupled with reduced environmental impact when compared to baseline methods. Our code is available at \url{https://github.com/jingwu6/LM_AG}