Goal Attainment on Long Tail Websites: An Information Foraging Approach

Information foraging theory (IFT) has emerged within the previous decade as a way of explaining the behavior of individuals as they hunt for information (Pirolli, 2007). In IFT, users forage for information using their metaphorical sense of smell which helps guides them through patchy areas of their environment. This preliminary research leverages IFT to build two versions of a clickstream model of information foraging that uses clickstream data to explain goal achievement. The goal being examined is the purchase of a product or submission of a contact form at long tail websites (i.e., sites with limited traffic). The first version of the model uses session-level panel data to examine across-website goal-seeking browsing patterns. Page-level data is used in the second version of the model to reason about browsing patterns within a website. The hypotheses and their related measures are presented for each version of the model

Characterisation and Germline Transmission of Cultured Avian Primordial Germ Cells

Background: Avian primordial germ cells (PGCs) have significant potential to be used as a cell-based system for the study and preservation of avian germplasm, and the genetic modification of the avian genome. It was previously reported that PGCs from chicken embryos can be propagated in culture and contribute to the germ cell lineage of host birds. Principal Findings: We confirm these results by demonstrating that PGCs from a different layer breed of chickens can be propagated for extended periods in vitro. We demonstrate that intracellular signalling through PI3K and MEK is necessary for PGC growth. We carried out an initial characterisation of these cells. We find that cultured PGCs contain large lipid vacuoles, are glycogen rich, and express the stem cell marker, SSEA-1. These cells also express the germ cell-specific proteins CVH and CDH. Unexpectedly, using RT-PCR we show that cultured PGCs express the pluripotency genes c-Myc, cKlf4, cPouV, cSox2, and cNanog. Finally, we demonstrate that the cultured PGCs will migrate to and colonise the forming gonad of host embryos. Male PGCs will colonise the female gonad and enter meiosis, but are lost from the gonad during sexual development. In male hosts, cultured PGCs form functional gametes as demonstrated by the generation of viable offspring. Conclusions: The establishment of in vitro cultures of germline competent avian PGCs offers a unique system for the study of early germ cell differentiation and also a comparative system for mammalian germ cell development. Primary PGC lines will form the basis of an alternative technique for the preservation of avian germplasm and will be a valuable tool fo

One Library’s Successful Venture in Providing Comprehensive Streaming Media Services

Thoroughly understanding what professors and instructors needed to accomplish their teaching goals with streaming video was the first step enabling one academic library to successfully manage a rapid increase in demand for streaming media. The second element was incorporating an expert understanding of copyright law and the nature of the video marketplace. This paper will strive to educate librarians and other professional library staff on how they can best integrate media streaming into mainstream library services for their campus faculty, as well as how to provide a full range of streaming services. The paper also will address workflow, communication with faculty, budget and license negotiations, copyright principles, fair use, and content delivery

Analyzing the effects of lactose on calcium absorption in premature infants using HR-ICP-Mass Spectrometry

Abstract only availableWith advances in neonatal care, premature infants are surviving at increasing rates. During the third trimester of pregnancy, the bone mineral content of infants rapidly increases. It is therefore becoming essential to accurately mimic the womb environment to maintain growth and sustain the health of premature infants as if they were in utero. Regulating calcium absorption in premature infants is crucial primarily for bone formation, as 99% of the calcium in the human body is found in the bones and the teeth. The effect of lactose containing formulas on calcium absorption in premature infants has not been well established. Concerns have been noted in the scientific community regarding lactose intolerance especially in premature infants, as lactase, the enzyme responsible for lactose digestion, is most readily detectible during the third trimester of pregnancy. In this study, in conjunction with Dr. Laura Hillman of the University of Missouri Hospital, each infant was fed lactose and maltose formulas during different weeks using a dual tracer method in which two calcium isotopes were administered, 44Ca orally and 46Ca intravenously. Urine samples were collected after 24 hours. Analysis related natural abundances of calcium isotopes to the measured values in the urine. Polyatomic ion interferences were differentiated from the calcium peaks by analyzing the samples at a resolution of 4000. Mathematical corrections for interferences caused by titanium and doubly charged strontium were determined by measuring the specific isotopes 47Ti and 87Sr++ and using known natural abundances of the interfering isotopes to correct each calcium count rate. Mathematical calculations relate the enriched isotope ratio measurements of 44Ca and 46Ca to calcium absorption. Analysis regarding the effect of lactose on calcium absorption is ongoing. Our data precision on the ICP-MS was acceptable with percent relative standard deviations (%RSD) for external precision over the course of a week at 1.4, 2.2, 0.71, and 1.4 for isotope ratios 42Ca: 43Ca, 42Ca: 44Ca, 42Ca: 46Ca, and 42Ca: 48Ca respectively. Daily internal precision (%RSD) values were .37, 1.3, .69, and 1.5. The precision shows the viability of utilizing HR-ICP-MS analysis for calcium isotope ratios.NSF-REU/NIH Program in Radiochemistr

Distributional reinforcement learning in prefrontal cortex

The prefrontal cortex is crucial for learning and decision-making. Classic reinforcement learning (RL) theories center on learning the expectation of potential rewarding outcomes and explain a wealth of neural data in the prefrontal cortex. Distributional RL, on the other hand, learns the full distribution of rewarding outcomes and better explains dopamine responses. In the present study, we show that distributional RL also better explains macaque anterior cingulate cortex neuronal responses, suggesting that it is a common mechanism for reward-guided learning

encephalitis in Florida

Background: Eastern Equine Encephalitis virus (EEEV) is an alphavirus with high pathogenicity in both humans and horses. Florida continues to have the highest occurrence of human cases in the USA, with four fatalities recorded in 2010. Unlike other states, Florida supports year-round EEEV transmission. This research uses GIS to examine spatial patterns of documented horse cases during 2005–2010 in order to understand the relationships between habitat and transmission intensity of EEEV in Florida. Methods: Cumulative incidence rates of EEE in horses were calculated for each county. Two cluster analyses were performed using density-based spatial clustering of applications with noise (DBSCAN). The first analysis was based on regional clustering while the second focused on local clustering. Ecological associations of EEEV were examined using compositional analysis and Euclidean distance analysis to determine if the proportion or proximity of certain habitats played a role in transmission. Results: The DBSCAN algorithm identified five distinct regional spatial clusters that contained 360 of the 438 horse cases. The local clustering resulted in 18 separate clusters containing 105 of the 438 cases. Both the compositional analysis and Euclidean distance analysis indicated that the top five habitats positively associated with horse cases were rural residential areas, crop and pastureland, upland hardwood forests, vegetated non-forested wetlands, an

Interaction of periodontitis and orthodontic tooth movement-an in vitro and in vivo study.

OBJECTIVES The aim of this in vitro and in vivo study was to investigate the interaction of periodontitis and orthodontic tooth movement on interleukin (IL)-6 and C-X-C motif chemokine 2 (CXCL2). MATERIALS AND METHODS The effect of periodontitis and/or orthodontic tooth movement (OTM) on alveolar bone and gingival IL-6 and CXCL2 expressions was studied in rats by histology and RT-PCR, respectively. The animals were assigned to four groups (control, periodontitis, OTM, and combination of periodontitis and OTM). The IL-6 and CXCL2 levels were also studied in human gingival biopsies from periodontally healthy and periodontitis subjects by RT-PCR and immunohistochemistry. Additionally, the synthesis of IL-6 and CXCL2 in response to the periodontopathogen Fusobacterium nucleatum and/or mechanical strain was studied in periodontal fibroblasts by RT-PCR and ELISA. RESULTS Periodontitis caused an increase in gingival levels of IL-6 and CXCL2 in the animal model. Moreover, orthodontic tooth movement further enhanced the bacteria-induced periodontal destruction and gingival IL-6 gene expression. Elevated IL-6 and CXCL2 gingival levels were also found in human periodontitis. Furthermore, mechanical strain increased the stimulatory effect of F. nucleatum on IL-6 protein in vitro. CONCLUSIONS Our study suggests that orthodontic tooth movement can enhance bacteria-induced periodontal inflammation and thus destruction and that IL-6 may play a pivotal role in this process. CLINICAL RELEVANCE Orthodontic tooth movement should only be performed after periodontal therapy. In case of periodontitis relapse, orthodontic therapy should be suspended until the periodontal inflammation has been successfully treated and thus the periodontal disease is controlled again

Humanities for the environment—A manifesto for research and action

Human preferences, practices and actions are the main drivers of global environmental change in the 21st century. It is crucial, therefore, to promote pro-environmental behavior. In order to accomplish this, we need to move beyond rational choice and behavioral decision theories, which do not capture the full range of commitments, assumptions, imaginaries, and belief systems that drive those preferences and actions. Humanities disciplines, such as philosophy, history, religious studies, gender studies, language and literary studies, psychology, and pedagogics do offer deep insights into human motivations, values, and choices. We believe that the expertise of such fields for transforming human preferences, practices and actions is ignored at society’s peril. We propose an agenda that focuses global humanities research on stepping up to the challenges of planetary environmental change. We have established Environmental Humanities Observatories through which to observe, explore and enact the crucial ways humanistic disciplines may help us understand and engage with global ecological problems by providing insight into human action, perceptions, and motivation. We present this Manifesto as an invitation for others to join the “Humanities for the Environment” open global consortium of humanities observatories as we continue to develop a shared research agenda