Bursting activity spreading through asymmetric interactions

People communicate with those who have the same background or share a common interest by using a social networking service (SNS). News or messages propagate through inhomogeneous connections in an SNS by sharing or facilitating additional comments. Such human activity is known to lead to endogenous bursting in the rate of message occurrences. We analyze a multi-dimensional self-exciting process to reveal dependence of the bursting activity on the topology of connections and the distribution of interaction strength on the connections. We determine the critical conditions for the cases where interaction strength is regulated at either the point of input or output for each person. In the input regulation condition, the network may exhibit bursting with infinitesimal interaction strength, if the dispersion of the degrees diverges as in the scale-free networks. In contrast, in the output regulation condition, the critical value of interaction strength, represented by the average number of events added by a single event, is a constant $1-1/\sqrt{2} \approx 0.3$, independent of the degree dispersion. Thus, the stability in human activity crucially depends on not only the topology of connections but also the manner in which interactions are distributed among the connections.Comment: 8 pages, 8 figure

Emergence of event cascades in inhomogeneous networks

There is a commonality among contagious diseases, tweets, urban crimes, nuclear reactions, and neuronal firings that past events facilitate the future occurrence of events. The spread of events has been extensively studied such that the systems exhibit catastrophic chain reactions if the interaction represented by the ratio of reproduction exceeds unity; however, their subthreshold states for the case of the weaker interaction are not fully understood. Here, we report that these systems are possessed by nonstationary cascades of event-occurrences already in the subthreshold regime. Event cascades can be harmful in some contexts, when the peak-demand causes vaccine shortages, heavy traffic on communication lines, frequent crimes, or large fluctuations in nuclear reactions, but may be beneficial in other contexts, such that spontaneous activity in neural networks may be used to generate motion or store memory. Thus it is important to comprehend the mechanism by which such cascades appear, and consider controlling a system to tame or facilitate fluctuations in the event-occurrences. The critical interaction for the emergence of cascades depends greatly on the network structure in which individuals are connected. We demonstrate that we can predict whether cascades may emerge in a network, given information about the interactions between individuals. Furthermore, we develop a method of reallocating connections among individuals so that event cascades may be either impeded or impelled in a network.Comment: 16 pages, 5 figure

Medical Procedure: Bone Marrow Aspiration and Biopsy

No Abstrac

24 hour incubation of ovary tissue in 17α20β-Dihyroxy-4-pregnon-3-one causes Bcl-2 and Pi3K-III expression to vary in Danio rerio

The present study investigated the effects of increasing concentrations of progesterone on cell death by monitoring the expression of mRNAs specific for genes in the apoptosis and autophagy cell death pathway in Danio rerio ovary tissue using quantitative (q)PCR. Progesterone is used to regulate oocyte maturation in vivo; however, synthetic progesterone in oral contraceptives is found in the environment. Primers for Bcl-2 and Pi3K-III were used to investigate gene activity via mRNA produced. The results of the present study revealed that gene activity was variable as revealed by qPCR analysis. After 24 hour exposure to progesterone Bcl-2 and Pi3K-III were expression was inconsistent. The inconsistency in results could have been to poor primer design in the Bcl-2 gene. For future directions new primers would be ordered specifically for apoptosis (p53 and Caspase-3), and a new reference gene. The independent study I am currently conducting in the Fall will utilize the same techniques and ideas of my summer research except I will be investigating the effects of progesterone on Pi3K-III, Caspase-3, and p53. My results will be presented in the Spring, 2015 at the Phi Sigma research symposium

Advances in Plant Tolerance to Biotic Stresses

Plants being sessile in nature encounter numerous biotic agents, including bacteria, fungi, viruses, insects, nematodes and protists. A great number of publications indicate that biotic agents significantly reduce crop productivity, although there are some biotic agents that symbiotically or synergistically co-exist with plants. Nonetheless, scientists have made significant advances in understanding the plant defence mechanisms expressed against biotic stresses. These mechanisms range from anatomy, physiology, biochemistry, genetics, development and evolution to their associated molecular dynamics. Using model plants, e.g., Arabidopsis and rice, efforts to understand these mechanisms have led to the identification of representative candidate genes, quantitative trait loci (QTLs), proteins and metabolites associated with plant defences against biotic stresses. However, there are drawbacks and insufficiencies in precisely deciphering and deploying these mechanisms, including only modest adaptability of some identified genes or QTLs to changing stress factors. Thus, more systematic efforts are needed to explore and expand the development of biotic stress resistant germplasm. In this chapter, we provided a comprehensive overview and discussed plant defence mechanisms involving molecular and cellular adaptation to biotic stresses. The latest achievements and perspective on plant molecular responses to biotic stresses, including gene expression, and targeted functional analyses of the genes expressed against biotic stresses have been presented and discussed

Advances in Plant Tolerance to Abiotic Stresses

During the last 50 years, it has been shown that abiotic stresses influence plant growth and crop production greatly, and crop yields have evidently stagnated or decreased in economically important crops, where only high inputs assure high yields. The recent manifesting effects of climate change are considered to have aggravated the negative effects of abiotic stresses on plant productivity. On the other hand, the complexity of plant mechanisms controlling important traits and the limited availability of germplasm for tolerance to certain stresses have restricted genetic advances in major crops for increased yields or for improved other traits. However, some level of success has been achieved in understanding crop tolerance to abiotic stresses; for instance, identification of abscisic acid (ABA) receptors (e.g., ABA-responsive element (ABRE) binding protein/ABRE binding factor (AREB/ABF) transcription factors), and other regulons (e.g., WRKYs, MYB/MYCs, NACs, HSFs, bZIPs and nuclear factor-Y (NF-Y)), has shown potential promise to improve plant tolerance to abiotic stresses. Apart from these major regulons, studies on the post-transcriptional regulation of stress-responsive genes have provided additional opportunities for addressing the molecular basis of cellular stress responses in plants. This chapter focuses on the progress in the study of plant tolerance to abiotic stresses, and describes the major tolerance pathways and implicated signaling factors that have been identified, so far. To link basic and applied research, genes and proteins that play functional roles in mitigating abiotic stress damage are summarized and discussed

Financial fire sales as continuous-state complex contagion

Trading activities in financial systems create various channels through which systemic risk can propagate. An important contagion channel is financial fire sales, where a bank failure causes asset prices to fall due to asset liquidation, which in turn drives further bank defaults, triggering the next rounds of liquidation. This process can be considered as a complex contagion, yet it cannot be modeled using the conventional binary-state contagion models because there is a continuum of states representing asset prices. Here, we develop a threshold model of continuous-state cascades in which the states of each node are represented by real values. We show that the solution of a multistate contagion model, for which the continuous states are discretized, accurately replicates the simulated continuous state distribution as long as the number of states is moderately large. This discretization approach allows us to exploit the power of approximate master equations to trace the trajectory of the fraction of defaulted banks and obtain the distribution of asset prices that characterize the dynamics of fire sales through overlapping portfolios. We examine the accuracy of the proposed method using real data on asset-holding relationships in exchange-traded funds. Our methodology could contribute to evaluating and controlling systemic risk that would emerge in various real-world networked systems in the form of continuous-state complex contagion

Conflict Resolution Training for Student Employees in an Academic Library

A Master's project paper under the department of Learning Design and Technology (LTEC). This paper was submitted in Spring 2022. This paper is about creation of an online module training for students employees working at the University of Hawaiʻi - West Oʻahu library.Many college students who are hired to work at the University of Hawaiʻi - West Oʻahu (UHWO) library often have little to no prior working experience. These student employees are often tasked with basic library duties such as shelving items or helping patrons locate information. Too frequently, student employees end up trying to help particularly difficult patrons or co-workers who are unaccepting of their help—situations that may result in unwanted interpersonal conflicts. Unfortunately, there is currently no formal training aimed at teaching them how to handle conflict using communication skills. To address this need, this project aimed to design and evaluate an online instructional module about conflict resolution. To design the instruction, research regarding library student employees, job motivation, and conflict resolution in the workplace were referenced. Keller’s (2016) ARCS-V model and Mayer’s (2005) Cognitive Theory of Multimedia Learning guided the project in terms of understanding how multimedia can be used to motivate and stimulate learners both cognitively and affectively. The project was evaluated through a usability study with three adults (n = 3), and a learning assessment with 17 adults (n = 17). The results indicated the module was organized into appropriate sections and most participants found the scenario-based videos engaging and relevant. Recommendations for future research include adding additional resources for future learning and expanding on the content for certain sections of the online module