687 research outputs found

    Man vs. machine: Investigating the effects of adversarial system use on end-user behavior in automated deception detection interviews

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    Deception is an inevitable component of human interaction. Researchers and practitioners are developing information systems to aid in the detection of deceptive communication. Information systems are typically adopted by end users to aid in completing a goal or objective (e.g., increasing the efficiency of a business process). However, end-user interactions with deception detection systems (adversarial systems) are unique because the goals of the system and the user are orthogonal. Prior work investigating systems-based deception detection has focused on the identification of reliable deception indicators. This research extends extant work by looking at how users of deception detection systems alter their behavior in response to the presence of guilty knowledge, relevant stimuli, and system knowledge. An analysis of data collected during two laboratory experiments reveals that guilty knowledge, relevant stimuli, and system knowledge all lead to increased use of countermeasures. The implications and limitations of this research are discussed and avenues for future research are outline

    A Three-Year Longitudinal Study of Change in Student Learning Styles

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    Kolb\u27s (1985) Learning Style Inventory and theories of learning preferences have become increasingly popular as a method for measuring preferred approaches for acquiring information and learning in classroom settings. Using Kolob\u27s (1985) theory; a number of researchers have argued that as students move through their college experience, their learning styles are likely to undergo significant changes. This paper reports on the results of a three-year longitudinal study that investigated the actual degree of learning style changes for a sample of college students in business, offering mixed support for the contention that learning styles are likely to change over a student\u27s college career

    The Effect of Voice Interactions on Drivers’ Guidance of Attention

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    The objective of the current study was to assess the effect of voice interactions with an in-vehicle system on drivers’ guidance of attention. Our approach was to examine the effect of voice interactions on endogenous control of attention using a modified Posner cue-target paradigm. Consistent with the bottleneck hypothesis, dual-task slowing was observed when drivers responded to an auditory task and to a pedestrian detection task concurrently. This interference contributed to disrupted attention allocation, especially when drivers could not rely on their endogenous control of attention

    Successful Treatment of an MTBE-impacted Aquifer Using a Bioreactor Self-colonized by Native Aquifer Bacteria

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    A field-scale fixed bed bioreactor was used to successfully treat an MTBE-contaminated aquifer in North Hollywood, CA without requiring inoculation with introduced bacteria. Native bacteria from the MTBE-impacted aquifer rapidly colonized the bioreactor, entering the bioreactor in the contaminated groundwater pumped from the site, and biodegraded MTBE with greater than 99 % removal efficiency. DNA sequencing of the 16S rRNA gene identified MTBE-degrading bacteria Methylibium petroleiphilum in the bioreactor. Quantitative PCR showed M. petroleiphilum enriched by three orders of magnitude in the bioreactor above densities pre-existing in the groundwater. Because treatment was carried out by indigenous rather than introduced organisms, regulatory approval was obtained for implementation of a full-scale bioreactor to continue treatment of the aquifer. In addition, after confirmation of MTBE removal in the bioreactor to below maximum contaminant limit levels (MCL; MTBE = 5 ÎŒg L−1), treated water was approved for reinjection back into the aquifer rather than requiring discharge to a water treatment system. This is the first treatment system in California to be approved for reinjection of biologically treated effluent into a drinking water aquifer. This study demonstrated the potential for using native microbial communities already present in the aquifer as an inoculum for ex-situ bioreactors, circumventing the need to establish non-native, non-acclimated and potentially costly inoculants. Understanding and harnessing the metabolic potential of native organisms circumvents some of the issues associated with introducing non-native organisms into drinking water aquifers, and can provide a low-cost and efficient remediation technology that can streamline future bioremediation approval processes

    Monomorphic Ventricular Arrhythmias in Athletes.

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    Ventricular arrhythmias are challenging to manage in athletes with concern for an elevated risk of sudden cardiac death (SCD) during sports competition. Monomorphic ventricular arrhythmias (MMVA), while often benign in athletes with a structurally normal heart, are also associated with a unique subset of idiopathic and malignant substrates that must be clearly defined. A comprehensive evaluation for structural and/or electrical heart disease is required in order to exclude cardiac conditions that increase risk of SCD with exercise, such as hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Unique issues for physicians who manage this population include navigating athletes through the decision of whether they can safely continue their chosen sport. In the absence of structural heart disease, therapies such as radiofrequency catheter ablation are very effective for certain arrhythmias and may allow for return to competitive sports participation. In this comprehensive review, we summarise the recommendations for evaluating and managing athletes with MMVA

    Testing the Cavefish Model: An Organism-focused Theory of Biological Design

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    Poster Abstract The Institute for Creation Research (ICR) is experimentally testing an engineering-based model of rapid biological adaptation: Continuous Environmental Tracking (CET). This model infers that organisms actively track conditions within specific environments to self-adjust through internal mechanisms and initiate adaptive functionality. The animal under investigation is Astyanax mexicanus (Mexican tetra), a freshwater fish with well-differentiated, interfertile morphotypes: eyed surface-dwelling fish (surface fish) with distinct pigmentation patterns, and eyeless cave-dwelling fish (cavefish) with minimal pigmentation. Aquaria within our newly established laboratory contain breeding pairs of cavefish exposed to either (A) cyclical light/dark patterns of full-spectrum high-intensity light, (B) minimal light combined with high CO2(low pH) levels or (C) deionized water. Preliminary results show that (1) cavefish rapidly increase pigmentation when exposed to high-intensity light, and (2) do not exhibit injurious behavior or physiology in low pH water; (3) surface fish lose pigmentation across their body in low pH or deionized water conditions; (4) adult cavefish and surface fish respond rapidly within weeks-to-months of experimental treatments. Thus far, preliminary results imply that high-intensity light may stimulate the induction of latent melanin synthesis pathways in adult cavefish. Second, pre-acclimation of cavefish to acidic water chemistry likely reflects conditions within their native cave environments. Third, comparative loss of pigmentation in adult surface fish exposed to darkness and low pH or deionized water suggests they actively self-adjust, and that adaptive traits are reversable. Fourth, in contrast to cavefish, surface fish indicate non-acclimation to a simulated cave environment. Lastly, all responses by A. mexicanus to experimental treatments occur without undergoing multigenerational cycles of death and survival. These implications do not support the conventional view that beneficial adaptations arise through random mutation, unregulated genomic recombination, or accumulation of unguided genetic variation – regardless of time scales. Therefore, organisms are the agents in control of adaptations and diversification. If correct, hypotheses attributing the exquisite fit of organisms to environments through the agency of nature are mistaken. We present a new direction in experimental science for the ICR, and Creation Science, that sees every organism as a divinely engineered creation with adaptive capacity across multiple environmental conditions

    Intracellular trafficking and secretion of adiponectin is dependent on GGA coated vesicles

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    Adiponectin (Acrp30) is an insulin-sensitizing hormone produced and secreted exclusively by adipose tissue. Confocal fluorescent microscopy demonstrated the colocalization of adiponectin with the Golgi membrane markers p115, ÎČ-COP, and the trans-Golgi network marker, syntaxin 6. Treatment of cells with brefeldin A redistributed adiponectin to the endoplasmic reticulum where it colocalized with the chaperone protein BIP and inhibited secretion of adiponectin demonstrating a requirement for a functional Golgi apparatus for adiponectin release. Confocal fluorescent microscopy also demonstrated a colocalization of endogenous adiponectin with that of expressed GGA1myc (Golgi-localizing Îł-adaptin ear homology ARF-binding protein) but with no significant overlap between adiponectin and the GGA2myc or GGA3myc isoforms. Consistent with confocal fluorescent microscopy, transmission electron microscopy demonstrated the colocalization of GGA1 with adiponectin. Although GGA1 did not directly interact with the adiponectin protein, the adiponectin enriched membrane compartments of adipocyte were precipitated by a GST-GGA1 cargo binding domain (VHS) fusion protein but not with a GST-GGA2 VHS or GST-GGA3 VHS fusion proteins. Moreover, co-expression of adiponectin with a GGA1 dominant-interfering mutant (GGA1-VHS GAT domain) resulted in a marked inhibition of adiponectin secretion in both 3T3L1 adipocytes and HEK293 cells, whereas no inhibition was detected with the truncated mutants GGA2-VHSGAT or GGA3-VHSGAT. Moreover, co-expression of wild type GGA1 with adiponectin enhanced secretion of adiponectin. Interestingly, leptin secretion was unaffected by neither the wild type form or GGA1 mutant. Taken together these data demonstrate that the trafficking of adiponectin through its secretory pathway is dependent on GGA-coated vesicles

    Low-energy Bluetooth for Detecting Real-world Penetrance of Bystander Naloxone Kits: A Pilot Study

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    Opioid overdose is a growing public health emergency in the United States. The antidote naloxone must be administered rapidly after opioid overdose to prevent death. Bystander or take-home naloxone programs distribute naloxone to opioid users and other community members to increase naloxone availability at the time of overdose. However, data describing the natural history of take- home naloxone in the hands of at-risk individuals is lacking. To understand patterns of naloxone uptake in at-risk users, we developed a smart naloxone kit that uses low-energy Bluetooth (BLE) to unobtrusively detect the transit of naloxone through a hospital campus. In this paper, we describe development of the smart naloxone kit and results from the first 10 participants in our pilot study

    Insulation of a synthetic hydrogen metabolism circuit in bacteria

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    <p>Abstract</p> <p>Background</p> <p>The engineering of metabolism holds tremendous promise for the production of desirable metabolites, particularly alternative fuels and other highly reduced molecules. Engineering approaches must redirect the transfer of chemical reducing equivalents, preventing these electrons from being lost to general cellular metabolism. This is especially the case for high energy electrons stored in iron-sulfur clusters within proteins, which are readily transferred when two such clusters are brought in close proximity. Iron sulfur proteins therefore require mechanisms to ensure interaction between proper partners, analogous to many signal transduction proteins. While there has been progress in the isolation of engineered metabolic pathways in recent years, the design of insulated electron metabolism circuits <it>in vivo </it>has not been pursued.</p> <p>Results</p> <p>Here we show that a synthetic hydrogen-producing electron transfer circuit in <it>Escherichia coli </it>can be insulated from existing cellular metabolism via multiple approaches, in many cases improving the function of the pathway. Our circuit is composed of heterologously expressed [Fe-Fe]-hydrogenase, ferredoxin, and pyruvate-ferredoxin oxidoreductase (PFOR), allowing the production of hydrogen gas to be coupled to the breakdown of glucose. We show that this synthetic pathway can be insulated through the deletion of competing reactions, rational engineering of protein interaction surfaces, direct protein fusion of interacting partners, and co-localization of pathway components on heterologous protein scaffolds.</p> <p>Conclusions</p> <p>Through the construction and characterization of a synthetic metabolic circuit <it>in vivo</it>, we demonstrate a novel system that allows for predictable engineering of an insulated electron transfer pathway. The development of this system demonstrates working principles for the optimization of engineered pathways for alternative energy production, as well as for understanding how electron transfer between proteins is controlled.</p

    Membrane-associated heparan sulfate is not required for rAAV-2 infection of human respiratory epithelia

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    BACKGROUND: Adeno-associated virus type 2 (AAV-2) attachment and internalization is thought to be mediated by host cell membrane-associated heparan sulfate proteoglycans (HSPG). Lack of HSPG on the apical membrane of respiratory epithelial cells has been identified as a reason for inefficient rAAV-2 infection in pulmonary applications in-vivo. The aim of this investigation was to determine the necessity of cell membrane HSPG for efficient infection by rAAV-2. RESULTS: Rates of transduction with rAAV2-CMV-EGFP3 in several different immortalized airway epithelial cell lines were determined at different multiplicities of infection (MOI) before and after removal of membrane HSPG by heparinase III. Removal of HSPG decreased the efficacy of infection with rAAV2 by only 30–35% at MOI ≀ 100 for all of respiratory cell lines tested, and had even less effect at an MOI of 1000. Studies in mutant Chinese Hamster Ovary cell lines known to be completely deficient in surface HSPG also demonstrated only moderate effect of absence of HSPG on rAAV-2 infection efficacy. However, mutant CHO cells lacking all membrane proteoglycans demonstrated dramatic reduction in susceptibility to rAAV-2 infection, suggesting a role of membrane glycosaminoglycans other than HSPG in mediating rAAV-2 infection. CONCLUSION: Lack of cell membrane HSPG in pulmonary epithelia and other cell lines results in only moderate decrease in susceptibility to rAAV-2 infection, and this decrease may be less important at high MOIs. Other cell membrane glycosaminoglycans can play a role in permitting attachment and subsequent rAAV-2 internalization. Targeting alternative membrane glycosaminoglycans may aid in improving the efficacy of rAAV-2 for pulmonary applications
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