Synthesis of Electrically Conductive Polylactic Acid Composites for 3D Printing

3D printing technology is a process of synthesizing an object by slicing a three-dimensional object into two-dimensional layers. It is making its mark as it reshapes product development and manufacturing industry in which everyone can participate in the process of 3D printing.The demand for various types of materials is increasing as customers become more innovative with designs. The overarching goal of this project was to create innovative 3D printing materials for a conventional 3D printer. Conductive filaments allow us to 3D print electrically conductive components using almost any commercially available desktop 3D printer. The electrically conductive filament for this research was made with carbon black and clear polylactic acid (PLA) pellets. Two different experimental methods were carried out to produce electrically conductive filaments. The first method involved a heating treatment of PLA pellets whereas the second method included a plasticizer to ease the process. Resistance measurements were taken for samples produced with both methods. The resistance increased as the length of the sample increased while the width was held constant. The resistance measurements were inconsistent which may be due to the non-uniform surface. The surface and cross sections of a 3D sample were studied under scanning electron microscope (SEM) machine. Certain features of the composite as well as the thermoplastic were observed with the SEM images

A Comparison of Alternative Forecast Models of REIT Volatility

This study compares the relative performance of several well-known models in the forecasting of REIT volatility. Overall our results suggest that long-memory models (ARFIMA & FIGARCH) provide the best forecasts. Using either a large sample or some statistically justified small subsamples, we find that long memory models consistently outperform their short-memory counterparts (GARCH & Stochastic Volatility models) over a variety of forecast horizons. We also find that asymmetric models (EGARCH & FIEGARCH) are the worst performers among all models. Our study complements and extends a recent study of Cotter and Stevenson (2008) which demonstrates the usefulness of long-memory models in modeling REIT volatility. We conclude that in addition to modeling REIT volatility, long-memory models should also be adopted to forecast REIT volatility

Long Term Dependence of Popular and Neglected Stocks

In this study, we establish a connection between the levels of market attentions of a stock with its long memory features. We construct two portfolios of US equities based on Doyle et al’s (2006) criteria for neglected and popular stocks and measure the degrees of persistence for their daily returns from January 1, 2003 to December 31, 2007. We find that all stocks except for one display anti-persistence in the neglect portfolio; while the popular portfolio stocks uniformly display random walk returns. This suggests that there is a connection between the persistence features of stock return series and the levels of “neglect” of stocks. We use book to market ratio, analyst coverage, and transaction frictions to classify the levels of market neglect of stocks. Based on our study, while these criteria combined appear to contribute to the long memory features of daily returns of stocks, we also suspect the presence of other factors driving the persistence of stock returns

Application of Biostatistics and Bioinformatics Tools to Identify Putative Transcription Factor- Gene Regulatory Network of Ankylosing Spondylitis and Sarcoidosis

Transcription factors and corresponding cis-regulatory elements are considered key components in gene regulation. We combined biostatistics and bioinformatics tools to streamline identification of putative transcription factor-gene regulatory networks unique for two immune-mediated diseases, ankylosing spondylitis and sarcoidosis. After identifying differentially expressed genes from microarrays, we employed tightCluster to find tight clusters of potentially co-regulated genes. By subsequently applying bioinformatics tools to search for common cis-regulatory elements, putative transcription factor-gene regulatory networks were found. Recognition of these networks by applying this methodology could pave the way for new insights into disease pathogenesis

Retention and Student Success: A Study of First Time, Full Time First-Generation Students at UNC Pembroke

First generation students face unique challenges in retention and graduation in colleges and universities. Recently, EAB released a study indicating that 90% of low-income, first generation students did not graduate on time within six years, particularly underrepresented minority students. UNCP is the top diverse institution in the South and had low retention rates and graduation rates compared with other UNC institutions in the past. For instance, 59% of our students were underrepresented minority students; and more than 33% of Freshmen were identified as first generation in Fall 2015. In addition, among students who graduated in May 2015, 39% were identified as first generation.The purpose of this study is to find how well our first generation students have done compared to other racial groups at UNCP, particularly Fall-to-Fall retention and six-year graduation. The results may help us to improve our services and add/adjust some programs to better serve the student body in the future.The study will focus on first-time, full-time (FTFT) Freshmen who were identified as first-generation in FAFSA application at UNCP. The cohorts included the FTFT Freshmen from Fall 2008 to Fall 2010

A Multi-Country Study Exploring Relationship of Lifestyles to Ethnocentrism

In this paper, we study consumer market segments in four Latin American countries and one U.S. territory by using lifestyle patterns and ethnocentrism. We partition consumer ethnocentrism into low, medium, and high levels, and then investigate the relationship between each level of consumer ethnocentrism and lifestyles. Furthermore, the impacts of gender, age, and marital status on the relationship between ethnocentrism and life style are explored. Data for the study was collected through self-survey in major cities in these countries. The results reveal distinct ethnocentrism- lifestyle relationship patterns at different levels of consumer ethnocentrism among the five Latin American regions. Especially, at the high ethnocentrism level, consumer lifestyles have significant influence on the consumers‘ ethnocentric tendencies. In addition, we found that the older consumers at the high ethnocentrism level exhibit significant relationship to their lifestyle. These findings have considerable implications for marketers in that, it opens up more opportunities for them in comparison to what others have been exposed to through extant research. Secondly, for marketers who are already operating in a global environment, our analysis offers them ideas in market segmentation, environmental scanning and opportunity analysis

Effects of air supply operation on the distribution and spatial differences of airflow field in conditioned room: A CFD Study

In air-blast freezer, there are differences in food freezing process at different locations due to the non-uniform airflow distribution in freezing chamber. In this paper, a decoupling method was used to simulate freezing process of food products at different locations. Firstly, the internal airflow distribution model of the freezing chamber was established to simulate the airflow field in freezing chamber under different velocities of air supply. The mainstream air flow rate around each food product was then calculated as the ambient air velocity at which the food freezes. Then, a validated lumped parameter model was used to simulate the freezing process of individual food product, and the effects of freezing conditions on freezing process at different locations were studied. The results showed that there were large differences in the freezing conditions of foods at different locations in freezing chamber, which were mainly reflected by the difference in ambient air velocity. Compared to air velocity, air temperature was distributed rather uniformly in freezing chamber. With the increase of supply air velocity of air coolers, the ambient air velocity around food products in freezing chamber increased almost linearly

Characterization of OAZ1 and its potential functions in goose follicular development

Background: Ornithine decarboxylase antizyme 1 (OAZ1) is an important regulator of polyamine synthesis and uptake. Our previous studies indicated that high OAZ1 expression in the ovaries of laying geese is responsible for poor egg production. In the present study, the molecular characterization of goose OAZ1 gene was analyzed, as well as the expression profile in various follicular tissues. Results: An 873-bp cDNA sequence of the OAZ1 gene (Accession No. KC845302) with a +1 frameshift site (+175T) was obtained. The sequence consisted of a 652-bp two overlapping open reading frames (a putative protein with 216 amino acids). The OAZ domain, OAZ signature and OAZ super family domain were prominent conserved regions among species. As the follicle size increased, OAZ1 abundance showed an increasing trend during follicular development, while it decreased during follicular regression. The level of OAZ1 mRNA expression was the lowest in the fifth largest preovulatory follicle, and was 0.65-fold compared to the small white follicle (P < 0.05). OAZ1 mRNA expression in the largest preovulatory and postovulatory follicle was 2.11- and 2.49-fold compared to the small white follicle, respectively (P < 0.05). Conclusions: The goose OAZ1 structure confirms that OAZ1 plays an important role in ornithine decarboxylase-mediated regulation of polyamine homeostasis. Our findings provide an evidence for a potential function of OAZ1 in follicular development, ovulation and regression

Inhibitory Effect and Mechanism of Lactiplantibacillus plantarum HB13-2 on Candida albicans

This study explored the inhibitory effect and mechanism of the culture supernatant of Lactiplantibacillus plantarum HB13-2 on Candida albicans. The minimum inhibitory concentration was determined by the double dilution method. Then, the fluorescent dye calcofluor white (CFW) was used to stain the cell wall and observe it. The results showed that the supernatant enhanced the fluorescence intensity and damaged the cell wall. Flow cytometry and fluorescence microscopy showed that the supernatant changed the membrane permeability of C. albicans. The transmembrane potential was detected using the fluorescent probe DiSC3(5), and it was found that the fluorescence intensity was enhanced, indicating that the supernatant caused dissipation of the transmembrane potential. Through microstructural observation by scanning electron microscopy (SEM), it was found that the supernatant of Lactobacillus plantarum HB13-2 caused cellular deformation and leakage of intracellular contents. As detected by fluorescence staining with 2’,7’-dichlorodihydrofluorescin diacetate (DCFH-DA) and Rhodamine-123, the supernatant resulted in accumulation of a large amount of intracellular reactive oxygen species (ROS) and increased mitochondrial membrane potential. In conclusion, the supernatant of L. plantarum HB13-2 can deform cells by destroying the cell wall and membrane and lead to mitochondrial damage, thereby inhibiting C. albicans. This study will provide a scientific basis for the development of L. plantarum HB13-2 as an oral probiotic