Miracle-dz/UniFAR-FTUs huggingface dataset:
The Cytotoxic and Antimicrobial Properties of Pine Essential Oils: A Characterization and Comparison

In the forestry industry, the pine tree species are important because of their durable timber and fast growth. In Arkansas, trees such as the loblolly pine compose almost a third of the timberland, seven million acres. In addition to the lignocellulosic biomass, pine bark and needles potentially have industrial importance as a waste stream from which high value (e.g., pharmaceutical, cosmetics) chemicals could be extracted, which could potentially increase the profit margin of forestry operations. In this research, the possibility that pine needles harvested from industry processed pine tree residues could be used as an antibacterial or cytotoxic chemical agent in order to provide an added value co-product for the lumber industry was investigated. Pinus taeda (loblolly pine tree) forestry residue and Pinus echinata (shortleaf pine tree) leaf essential oils were both effective cytotoxic agents against the Caco-2 cell line (heterogeneous human epithelial colorectal adenocarcinoma). The P. taeda caused complete cell culture death in 24 hours at the lowest concentration used, 0.15%, while the P. echinata essential oil was effective at 0.33%, reaching complete cell death at 1.25%. Both essential oils were tested against and showed some effectiveness against cocktails of the four bacterial species: Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Salmonella enterica. Both these properties indicate that essential oils of both the P. taeda (loblolly pine tree) needle residue and P. echinata (shortleaf pine tree) needles have the potential to provide added value to the forestry industry, provided that their cytotoxic properties are further examined. ACKNOWLEDGMENTS I am very grateful to: The National Science Foundation, the Arkansas Asset Initiative, Arkansas Center for Plant Powered Production, the Arkansas Biosciences Institute, and the Department of Biological and Agricultural Engineering at the University of Arkansas for financially supporting this project. The University of Arkansas Libraries for financially supporting my education. Dr. Elizabeth Martin, for providing guidance concerning the experimental work and procedures. Patricia Kirkwood, for your support and help during my stay. Dr. Sun-Ok Lee, for allowing me usage of your resources. My committee members, Dr. Clausen and Dr. Costello, for their constructive inputs in making this thesis better. My advisor and thesis director, Dr. Danielle Julie Carrier, for guiding me through this entire endeavor. You have helped me grow as a scientist, engineer, student, and as a person. DEDICATION To Jay Sakul, Carissa Sakul, and Kevin Sakul, for their support and love. TABLE OF CONTENTS
Physical properties of interstellar filaments

We analyze the physical parameters of interstellar filaments that we describe by an idealized model of isothermal self-gravitating infinite cylinder in pressure equilibrium with the ambient medium. Their gravitational state is characterized by the ratio f_cyl of their mass line density to the maximum possible value for a cylinder in a vacuum. Equilibrium solutions exist only for f_cyl < 1. This ratio is used in providing analytical expressions for the central density, the radius, the profile of the column density, the column density through the cloud centre, and the fwhm. The dependence of the physical properties on external pressure and temperature is discussed and directly compared to the case of pressure-confined isothermal self-gravitating spheres. Comparison with recent observations of the fwhm and the central column density N_H(0) show good agreement and suggest a filament temperature of ~10 K and an external pressure p_ext/k in the range 1.5x10^4 K/cm^3 to 5x10^4 K/cm^3. Stability considerations indicate that interstellar filaments become increasingly gravitationally unstable with mass line ratio f_cyl approaching unity. For intermediate f_cyl>0.5 the instabilities should promote core formation through compression, with a separation of about five times the fwhm. We discuss the nature of filaments with high mass line densities and their relevance to gravitational fragmentation and star formation.
Social influence model and electronic word of mouth

Compared with laptop or desktop computers, mobile devices offer greater flexibility in time and space, thus enabling consumers to be connected online more continually. In addition, their small size, portability and ease of use with location-based capabilities facilitate sending and receiving timely information in the right place. Drawing upon a social influence model proposed by Dholakia et al. (2004), this paper proposes a causal model for consumer participation in electronic word of mouth (eWOM), and compares the effects of PC-based and mobile-based eWOM (hereafter pcWOM and mWOM, respectively). The paper posits social identity, motivations (purposive value, social enhancement and intrinsic enjoyment), inherent novelty seeking and opinion leadership as antecedents affecting desire (individual-level driver) and social intention (grouplevel driver) to engage in eWOM. A total of 271 survey responses were collected from consumers in Japan. The proposed model fits the data reasonably well; all hypotheses are supported. The results reveal that desire only partially mediates the effects on social intention of social identity. Compared with pcWOM participants, mWOM participants exhibit significantly higher perceptions on social intention, intrinsic enjoyment and cognitive social identity. After recognising important limitations, theoretical implications are discussed and future research directions suggested.
If larvae were smart: a simple model for optimal settlement behavior of competent larvae

Much research has been done on larval settlement cues. Rather than having simple fixed responses to constant environmental stimuli, it seems likely that settlement decisions made by individual larvae should vary depending on the individual and the conditions under which it encoun- ters that cue. Here, we present a simple stochastic dynamic programming model that explores the conditions under which larvae may maximize their lifetime fitness by accepting lower quality habitat rather than continuing to search for superior habitat. Our model predicts that there is a relatively nar- row range of parameter values over which larval selectivity among habitat types changes dramati- cally from 1 (larvae accept only optimal substrata) to 0 (indiscriminant settlement). This narrow range coincides with our best estimate of parameter values gleaned from empirical studies, and the model output matches data for the polychaete worm Hydroides dianthus remarkably well. The relative availability of habitats and the total time available to search for high quality habitat (i.e. the ability to delay metamorphosis) had the greatest effects on larval selectivity. In contrast, intuitive factors, including larval energetics and mortality, showed little effect on larval habitat preference, but could still alter the proportion of larvae settling in different habitats by reducing search time. Our model predicts that a given larva may behave differently depending on where it falls in the optimality deci- sion matrix at the instant in which it locates substrata. This model provides a conceptual framework in which to conduct future studies involving variability in settlement decisions among individual lar- vae, and in which to consider the selective forces driving the evolution of specific larval settlement cues. Our results suggest that a combination of the maximum search period and the relative fre- quency and quality of optimal habitat likely exert the greatest influence on the evolution of larval selectivity in the field.
COLOR–MAGNITUDE RELATIONS OF ACTIVE AND NON-ACTIVE GALAXIES IN THE CHANDRA DEEP FIELDS: HIGH-REDSHIFT CONSTRAINTS AND STELLAR-MASS SELECTION EFFECTS

We extend color–magnitude relations for moderate-luminosity X-ray active galactic nucleus (AGN) hosts and non-AGN galaxies through the galaxy formation epoch (z ≈ 1–4) in the Chandra Deep Field-North and Chandra Deep Field-South (CDF-N and CDF-S, respectively; jointly CDFs) surveys. This study was enabled by the deepest available X-ray data from the 2 Ms CDF surveys as well as complementary ultradeep multiwavelength data in these regions. We utilized analyses of color–magnitude diagrams (CMDs) to assess the role of moderate-luminosity AGNs in galaxy evolution. First, we confirm some previous results and extend them to higher redshifts, finding, for example, that (1) there is no apparent color bimodality (i.e., the lack of an obvious red sequence and blue cloud) for AGN hosts from z ≈ 0to2, but non-AGN galaxy color bimodality exists up to z ≈ 3 and the relative fraction of red-sequence galaxies generally increases as the redshift decreases (consistent with a blue-to-red migration of galaxies), (2) most AGNs reside in massive hosts and the AGN fraction rises strongly toward higher stellar mass, up to z ≈ 2–3, and (3) the colors of both AGN hosts and non-AGN galaxies become redder as the stellar mass increases, up to z ≈ 2–3. Second, we point out that, in order to obtain a complete and reliable picture, it is critical to use mass-matched samples to examine color–magnitude relations of AGN hosts and non-AGN galaxies. We show that for mass-matched samples up to z ≈ 2–3, AGN hosts lie in the same region of the CMD as non-AGN galaxies; i.e., there is no specific clustering of AGN hosts in the CMD around the red sequence, the top of the blue cloud, or the green valley in between. The AGN fraction (≈ 10%) is mostly independent of host-galaxy color, providing an indication of the duty cycle of supermassive black hole growth in typical massive galaxies. These results are in contrast to those obtained with non-mass-matched samples where there is apparent AGN clustering in the CMD and the AGN fraction generally increases as the color becomes redder. We also find, for mass-matched samples, that the star formation rates of AGN hosts are typically a factor of ≈ 2–3 larger than those of non-AGN galaxies at z ≈ 0–1, whereas this difference diminishes at z ≈ 1–3. With mass-selection effects taken into account, we find that almost all of the results obtained in this work can reasonably be explained by two main ingredients, color–mass correlation (i.e., X-ray AGNs preferentially reside in massive galaxies that generally tend to be redder than less-massive galaxies) and passive or secular evolution of galaxies. Our results show that the presence of moderate-luminosity AGN activity does not have a significant effect on the colors of galaxies and thus tightly constrain any effects from moderate-luminosity AGN feedback upon color–magnitude properties over the ≈ 80% of cosmic time during which most of galaxy formation occurred.
In-service Teachers' Implementation and Understanding of STEM Project Based Learning

In this study, we discussed the participating teachers‟ implementation and understanding of science, technology, engineering and mathematics (STEM) project based learning (PBL). A research team at a STEM center systematically offered professional development activities to 92 teachers in an urban school district in the southern U.S. To investigate the teachers‟ implementation and understanding of the STEM PBL pedagogy, we conducted a collective case study with five teachers. Study data included interviews, in-class observations, and lesson plans designed and implemented by the teachers. The results of this study indicated that the PD sessions were effective in communicating several important concepts about STEM PBL. Nevertheless, our observations revealed that five teachers‟ classroom enactments did not necessarily convey their understanding of STEM PBL.
Effect of moisture content on some physical properties of sheanut (Butyrospernum Paradoxum)

A b s t r a c t. The effect of moisture content on the physical properties of sheanut (Butyrospernum paradoxum) was determined to explore the possibility of developing its bulk handling and processing equipment. In the moisture range of 6 to 27.9% (d.b.), the major, intermediate and minor axes of the nut increased from 37 to 39.4, 26.8-28.3 and 25.9-26.8 mm, respectively. The arithmetic mean, geometric mean and equivalent sphere effective diameters determined at the same moisture level were significantly different from each other, with the arithmetic mean diameter being of the highest value and the equivalent sphere effective diameter yielding the volume that is closest to the experimentally determined value. In the above moisture range, one thousand nut weight and volume increased linearly with moisture content from 7.8 to 10.6 kg and 12 360 to 14 030 mm 3 , respectively. Particle density, bulk density and angle of repose increased logarithmically with moisture content from 643 to 782 g cm -3 , 291.3-356.2 g cm -3 , and 24.7-25.1°, respectively, while porosity increased with increase in moisture content to a maxi- mum value of 56.5% at the moisture content of 22.7% (d.b.), and thereafter decreased to a value of 54.5% at the moisture content of 27.9% (d.e.). Static coefficient of friction increased linearly with moisture content from 0.300 to 0.394 in the above moisture range, and varied with structural surface. The maximum static coefficient of friction was on plywood with wood grains perpendicular to the direction of movement, while the minimum value was on formica (papreg). Regression equations that could be used to express the relationships existing between the physical properties and nut moisture content were established.
The Patterns of Acquisition of Syntactic Regularities in Pre-Secondary School Second Language Learners of English

The learning of complex syntactic structures of English by L2 learners have not been systematically dealt with in the available literature. This study investigated this problem, with the aim of replicating some works done in the L1, in order to determine their feasibility in the L2 perspective. Limited to a small sample, the study examined the developmental stages in the acquisition of English syntactic structures in 7 to 10-year-old children learning English as a second language. Six test constructs were used to examine linguistic competence over a wide range of surface structures, and statistical analysis provided the basis for interpretation of the general pattern of acquisition. The findings of the study show that the process of acquisition of syntactic structures continues actively during and after the primary school years among L2 learners, and they have implication not only for syntactic acquisition, but for language theory in general and L2 theory in particular.
The biology of biofilm bacteria from urinary tract catheters

Blasenkatheter bewachsen gewohnlich innerhalb kurzester Zeit nach der Applikation mit mikrobiellen Biofilmen. Die meisten Patienten zeigen keine Symptome. Es wurde untersucht, ob dieser Biofilme das Potenzial besitzen gefahrliche Infektionen auszulosen. Dazu wurden die mikrobiellen Gemeinschaften von 92 Blasenkatheter mittels der „single- strand- confirmation- polymorphism“- Methode analysiert. Funf reprasentative Biofilme wurden genauer untersucht. Drei Katheter wurden jeweils durch eine Art dominiert, zwei wurden in fast gleichen Anteilen von Proteus sp. / Enterococcus sp. und Pseudomonas sp. / Enterococcus sp. co-dominiert. Die Ergebnisse wurden durch Metaproteomanalysen bestatigt. Zusatzlich wurden neun verschiedene Stamme in Hinblick auf ihre Biofilmbildung und extrazellularen Enzymproduktion untersucht. Alle Isolate bildeten Biofilme, wobei Stenotrophomonas maltophilia und Enterococcus faecalis die starkste Biofilmbildung zeigten. Extrazellulare Enzyme wurden fur fast alle Arten nachgewiesen. Fur acht Antibiotika wurden die minimalen Hemmkonzentrationen ermittelt. Nur Gentamicin inhibierte das Wachstum bei acht von neun Isolaten, andere Antibiotika zeigten fast keine Wirkung. Schlieslich wurde der isolierte Myroides Stamm weiterer charakterisiert, da uber die Virulenz oder Anpassungen an den Wirtsorganismus von Myroides spp. wenig bekannt ist. Dieses Bakterium ist in der Lage an menschliche Zellen zu adharieren und zu invadieren. Elektonenmikroskopische Aufnahmen zeigten eine ungewohnliche Zellmorphologie mit Verzweigung und kappenartigen Strukturen an den Polen der Zellen. Einzelne Zellen wachsen bis zu 60 µm lang in Vollmedium. Durch Methoden der polyphasischen Taxonomie konnte keine eindeutige Artzugehorigkeit bewiesen werden. Die Sequenzierung des Genoms wurde nahezu abgeschlossen. Zusammenfassend konnte durch molekular- und mikrobiologische Methoden gezeigt werden, dass Bakterien aus Katheterbiofilmen das Potential haben schwere Infektionen auszulosen.
Predicting Taxi-Out Time at Congested Airports with Optimization-Based Support Vector Regression Methods

Accurate prediction of taxi-out time is significant precondition for improving the operationality of the departure process at an airport, as well as reducing the long taxi-out time, congestion, and excessive emission of greenhouse gases. Unfortunately, several of the traditional methods of predicting taxi-out time perform unsatisfactorily at congested airports. This paper describes and tests three of those conventional methods which include Generalized Linear Model, Softmax Regression Model, and Artificial Neural Network method and two improved Support Vector Regression (SVR) approaches based on swarm intelligence algorithm optimization, which include Particle Swarm Optimization (PSO) and Firefly Algorithm. In order to improve the global searching ability of Firefly Algorithm, adaptive step factor and Levy flight are implemented simultaneously when updating the location function. Six factors are analysed, of which delay is identified as one significant factor in congested airports. Through a series of specific dynamic analyses, a case study of Beijing International Airport (PEK) is tested with historical data. The performance measures show that the proposed two SVR approaches, especially the Improved Firefly Algorithm (IFA) optimization-based SVR method, not only perform as the best modelling measures and accuracy rate compared with the representative forecast models, but also can achieve a better predictive performance when dealing with abnormal taxi-out time states.
The importance of resolved microphysics to reintensification during the extratropical transition of tropical cyclones

The extratropical transition of tropical cyclones (hereafter TCs) can be a particularly complex process (e.g. DiMego and Bosart 1982; Harr and Elsberry 2000; Klein et al. 2000; Jones et al. 2003). As a general outline, however, as they progress northward they undergo what Klein et al. (2002) refer to as the transformation stage, which involves the loss of axisymmetry, an upper-level warm core, and other characteristics. However, if the TC remnant is able to interact with an upper-level system, a reintensification stage may then occur, and the system may become a potent extratropical cyclone. In order to learn more about the reintensification stage, an idealized study was performed using the An idealized modeling study (Ritchie and Elsberry 2003) was performed using the COAMPS R © regional model. A series of simulations was performed, each containing a lowlevel TC-like vortex and an upper-level trough of various strengths. It was found that, whereas the trough-induced minimum sea level pressure (SLP) was dependent on the strength of the trough, the minimum SLP of the reintensified TC remnant was almost insensitive to trough strength (and in all cases lower than that achieved in the troughonly simulations). Recently other idealized simulations have been performed to investigate the role of the trough/TC spatial configuration. In this case it was found that reintensification was highly sensitive to the details of the initial configuration (Ritchie 2005). All of the preceding simulations were performed using 27 km grid spacing on the finest, or only, grid. In this study increased resolution will be introduced into the simulations to allow a closer examination of the reintensification process, and in particular the role of resolved microphysical processes.
Exploring Greek Teachers’ Beliefs Using Metaphors

When teachers describe their roles through metaphors, they also construct specific personal meanings about teaching. Despite the frequency with which teachers and teaching are treated metaphorically there has been no previous systematic attempt to explore them in Greece. Our paper seeks to fill this void by examining the various metaphors used by teachers to describe the experience of teaching and suggests how and to what extent the understanding of the metaphors can be useful in exploring teachers' beliefs and how they may contribute to teacher education programs. A questionnaire was devised to a sample of 156 in-service teachers which focused on teachers' metaphors and their beliefs about teaching, teacher-student roles, classroom climate and their beliefs about knowledge. The findings of our research illustrate the various metaphors that Greek teachers hold, indicating that they have probably not elicited and elaborated them.
Miscibility and Nanoparticle Diffusion in Ionic Nanocomposites

We investigate the effect of various spherical nanoparticles in a polymer matrix on dispersion, chain dimensions and entanglements for ionic nanocomposites at dilute and high nanoparticle loading by means of molecular dynamics simulations. The nanoparticle dispersion can be achieved in oligomer matrices due to the presence of electrostatic interactions. We show that the overall configuration of ionic oligomer chains, as characterized by their radii of gyration, can be perturbed at dilute nanoparticle loading by the presence of charged nanoparticles. In addition, the nanoparticle’s diffusivity is reduced due to the electrostatic interactions, in comparison to conventional nanocomposites where the electrostatic interaction is absent. The charged nanoparticles are found to move by a hopping mechanism.
How can power discourses be changed

Social policy impact is partly determined by how policy is articulated and advocated, including which values are highlighted and how. We examine the influence of policy framing and reframing on outcomes, with particular reference to policies of the Delhi state government in India that target the practices of female feticide, infanticide and neglect that underlie the ‘daughter deficit’. Using Snow and Benford’s categories for understanding reframing processes, the paper outlines and applies a ‘model’ of reframing disputed issues, derived from looking at two famous campaigns – Gandhi’s 1930 Salt March in the struggle for Indian freedom from British rule and the African- American civil rights struggle of the 1950s and 60s. It argues that ‘carrot and stick’ policy measures, such as financial incentives and legal prohibitions, to counteract the ‘daughter deficit’ must be complemented by well crafted discursive interventions.