Problem-solving:Individual factors predictive of resistance to functional fixedness and effects of einstellung.

The purpose of this research was to replicate and expand two experimental procedures that have been fundamental to the understanding of problem solving and rigidity: functional fixedness and effects of Einstellung. Functional fixedness can be described as an instance in which negative transfer occurs and there is perceptual “blindness” to the versatility of an object. Einstellung is the tendency to utilize a more complicated and habitually primed procedure at the expense of simpler methods. Results were analyzed to identify individuals resistant to these natural effects and to determine the non-clinical personality factors as assessed by the Myers-Briggs Type Indicator (MBTI, Myers, McCaulley, Quenk, & Hammer, 1998) that contribute to rigidity and fixation. A majority of participants (60%) responded in the same manner to the cognitive fixation problems (either susceptible or resistant to both functional fixedness and effects of Einstellung), indicating a salient connection between the cognitive mechanisms activated by these two phenomena. A significant relationship was discovered between susceptibility to cognitive fixation and the Thinking/Feeling dimension on the MBTI.James W. EriksonKrug, DamonDraper, MatthewPolizzi, DavidDoctor of PhilosophyDepartment of Communication Disorders, Counseling, School, and Educational PsychologyCunningham Memorial library, Terre Haute,Indiana State UniversityILL-ETD-078DoctoralTitle from document title page. Document formatted into pages: contains 80 p.: ill. Includes abstract and appendi

All Who Wander: On the Prevalence and Characteristics of Multi-community Engagement

Although analyzing user behavior within individual communities is an active and rich research domain, people usually interact with multiple communities both on- and off-line. How do users act in such multi-community environments? Although there are a host of intriguing aspects to this question, it has received much less attention in the research community in comparison to the intra-community case. In this paper, we examine three aspects of multi-community engagement: the sequence of communities that users post to, the language that users employ in those communities, and the feedback that users receive, using longitudinal posting behavior on Reddit as our main data source, and DBLP for auxiliary experiments. We also demonstrate the effectiveness of features drawn from these aspects in predicting users' future level of activity. One might expect that a user's trajectory mimics the "settling-down" process in real life: an initial exploration of sub-communities before settling down into a few niches. However, we find that the users in our data continually post in new communities; moreover, as time goes on, they post increasingly evenly among a more diverse set of smaller communities. Interestingly, it seems that users that eventually leave the community are "destined" to do so from the very beginning, in the sense of showing significantly different "wandering" patterns very early on in their trajectories; this finding has potentially important design implications for community maintainers. Our multi-community perspective also allows us to investigate the "situation vs. personality" debate from language usage across different communities.Comment: 11 pages, data available at https://chenhaot.com/pages/multi-community.html, Proceedings of WWW 2015 (updated references

Semi-Automated Library Preparation for High-Throughput DNA Sequencing Platforms

Next-generation sequencing platforms are powerful technologies, providing gigabases of genetic information in a single run. An important prerequisite for high-throughput DNA sequencing is the development of robust and cost-effective preprocessing protocols for DNA sample library construction. Here we report the development of a semi-automated sample preparation protocol to produce adaptor-ligated fragment libraries. Using a liquid-handling robot in conjunction with Carboxy Terminated Magnetic Beads, we labeled each library sample using a unique 6 bp DNA barcode, which allowed multiplex sample processing and sequencing of 32 libraries in a single run using Applied Biosystems' SOLiD sequencer. We applied our semi-automated pipeline to targeted medical resequencing of nuclear candidate genes in individuals affected by mitochondrial disorders. This novel method is capable of preparing as much as 32 DNA libraries in 2.01 days (8-hour workday) for emulsion PCR/high throughput DNA sequencing, increasing sample preparation production by 8-fold

Long-term stability of earthen materials in contact with acidic tailings solutions

The objectives of the studies documented in this report were to use experimental and geochemical computer modeling tools to assess the long-term environmental impact of leachate movement from acidic uranium mill tailings. Liner failure (i.e., an increase in the permeability of the liner material) was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 years. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The high clay materials tested appear suitable for lining tailings impoundment ponds. The decreases in permeability are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. In conclusion the same mineralogical changes and contaminant reactions predicted by geochemical modeling and observed in laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 4 year history of acid attack

Depleted uranium is not toxic to rat brain endothelial (RBE4) cells

Abstract: Studies on Gulf War veterans with depleted uranium (DU) fragments embedded in their soft tissues have led to suggestions of possible DU-induced neurotoxicity. We investigated DU uptake into cultured rat brain endothelial cells (RBE4). Following the determination that DU readily enters RBE4 cells, cytotoxic effects were analyzed using assays for cell volume increase, heat shock protein 90 (Hsp90) expression, 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) reduction, and lactate dehydrogenase (LDH) activity. The results of these studies show that uptake of the U 3 O 8 uranyl chloride form of DU into RBE4 cells is efficient, but there are little or no resulting cytotoxic effects on these cells as detected by common biomarkers. Thus, the present experimental paradigm is rather reassuring and provides no indication for overt cytotoxicity in endothelial cells exposed to DU. Index Entries: Depleted uranium (DU); heavey metal toxicity; blood-brain barrier; endothelium. Article: INTRODUCTION Depleted uranium (DU) is a component of military munitions and is therefore the subject of important toxicity studies. Specifically, the possibility of DU neurotoxicity is under investigation. DU is a dense heavy metal used without reserve in many military applications. Chemically similar to natural uranium, but depleted of much of the radioactivity of the 235 U and 234 U isotopes, DU is a low-specific-activity metal that has several advantages for use as weapons material. Neurotoxicity could potentially arise from the chemical or radioactive properties of DU, and the level of neurotoxicity is as yet undetermined (1-3). Gulf War veterans with DU fragments embedded in their soft tissues were studied and the results suggested that there might be DU-associated effects on behavior and cognition (1-4). Rats embedded with DU fragments accumulated uranium in a range of tissues, with early levels highest in the kidney and a gradual increase in bone accumulation. Brain tissues were found to have far lower levels, with the hippocampus showing high levels among the brain regions following physiologically relevant exposures and cerebellum accumulating the highest levels upon extremely high exposure levels For a blood-borne contaminant to cause neurotoxicity, it must first cross the blood-brain barrier (BBB). This barrier protects the central nervous system (CNS) from toxicants in the blood, and its ability to protect against metal neurotoxicity was reviewed by Zheng et al. (7). The capillaries of the brain are lined with endothelial cells acting as the first line of defense in the BBB. The high degree of tightness of the junctions that link the endothelial cells virtually prevents any paracellular passage from occurring in physiological conditions. In addition, several transport proteins can increase the brain-to-blood efflux of various compounds (e.g., Pglycoproteins or multidrug resistance proteins [MDR] of the ATP-binding cassette [ABC]) (7). The molecula

The Resolved Asteroid Program - Size, shape, and pole of (52) Europa

With the adaptive optics (AO) system on the 10 m Keck-II telescope, we acquired a high quality set of 84 images at 14 epochs of asteroid (52) Europa on 2005 January 20. The epochs covered its rotation period and, by following its changing shape and orientation on the plane of sky, we obtained its triaxial ellipsoid dimensions and spin pole location. An independent determination from images at three epochs obtained in 2007 is in good agreement with these results. By combining these two data sets, along with a single epoch data set obtained in 2003, we have derived a global fit for (52) Europa of diameters (379x330x249) +/- (16x8x10) km, yielding a volume-equivalent spherical-diameter of 315 +/- 7 km, and a rotational pole within 7 deg of [RA; Dec] = [257,+12] in an Equatorial J2000 reference frame (ECJ2000: 255,+35). Using the average of all mass determinations available forEuropa, we derive a density of 1.5 +/- 0.4, typical of C-type asteroids. Comparing our images with the shape model of Michalowski et al. (A&A 416, 2004), derived from optical lightcurves, illustrates excellent agreement, although several edge features visible in the images are not rendered by the model. We therefore derived a complete 3-D description of Europa's shape using the KOALA algorithm by combining our imaging epochs with 4 stellar occultations and 49 lightcurves. We use this 3-D shape model to assess these departures from ellipsoidal shape. Flat facets (possible giant craters) appear to be less distinct on (52) Europa than on other C-types that have been imaged in detail. We show that fewer giant craters, or smaller craters, is consistent with its expected impact history. Overall, asteroid (52) Europa is still well modeled as a smooth triaxial ellipsoid with dimensions constrained by observations obtained over several apparitions.Comment: Accepted for publication in Icaru