• Conceptual profile of chemistry: a framework for enriching thinking and action in chemistry education

      Freire, Melquesedeque; Talanquer, Vicente; Amaral, Edenia; Univ Arizona, Dept Chem & Biochem (ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD, 2019-03-24)
      Understanding the nature of chemical thinking and action, as well as their application and impact on our world should be central goals of chemistry education at all educational levels. However, traditional school chemistry is still mostly focused on having students learn the body of declarative knowledge built over the years in the discipline. Achieving changes in curriculum and teaching practices in this context remains a challenging task. Studies in the history and philosophy of the discipline suggest that chemistry has unique characteristics that need to be recognised and considered in chemistry education. Many of these studies point to a pluralism in the discipline, and in the understanding of and about chemistry, that should be characterised and incorporated into our educational models. In this essay, we have attempted to build such a characterisation using conceptual profiles theory to propose a framework that can be used to enrich and support the thinking and action of chemistry teachers at all educational levels.
    • Quantal Risk Assessment Database: A Database for Exploring Patterns in Quantal Dose-Response Data in Risk Assessment and its Application to Develop Priors for Bayesian Dose-Response Analysis.

      Wheeler, Matthew W; Piegorsch, Walter W; Bailer, Albert John; Univ Arizona, Interdisciplinary Program Stat (WILEY, 2019-03-01)
      Quantitative risk assessments for physical, chemical, biological, occupational, or environmental agents rely on scientific studies to support their conclusions. These studies often include relatively few observations, and, as a result, models used to characterize the risk may include large amounts of uncertainty. The motivation, development, and assessment of new methods for risk assessment is facilitated by the availability of a set of experimental studies that span a range of dose-response patterns that are observed in practice. We describe construction of such a historical database focusing on quantal data in chemical risk assessment, and we employ this database to develop priors in Bayesian analyses. The database is assembled from a variety of existing toxicological data sources and contains 733 separate quantal dose-response data sets. As an illustration of the database's use, prior distributions for individual model parameters in Bayesian dose-response analysis are constructed. Results indicate that including prior information based on curated historical data in quantitative risk assessments may help stabilize eventual point estimates, producing dose-response functions that are more stable and precisely estimated. These in turn produce potency estimates that share the same benefit. We are confident that quantitative risk analysts will find many other applications and issues to explore using this database.
    • Computer Aided System for Users with Visual Impairments

      Kirboyun, Sevgi; Univ Arizona, Coll Educ, Dept Disabil & Psychoeduc Studies (IEEE, 2018)
      Screen readers enable people with visual impairment (VI) to have equal access to written information both on computers and smartphones. This paper presents an overview of screen readers that allow users with VI read the text materials and describe images on the computer screen by using a special software program to synthesize as speech. We study three aspects of the screen readers in terms of their accessibility. First, we invest on developing websites, apps, and software programs by following web content accessibility guidelines to ensure accessibility. We than conduct research on compatibility of the websites, apps, and software programs with screen readers. Last, we inform about descriptions of the images by creating alternative texts.
    • TRIMMED SERENDIPITY FINITE ELEMENT DIFFERENTIAL FORMS

      Gillette, Andrew; Kloefkorn, Tyler; Univ Arizona, Dept Math (AMER MATHEMATICAL SOC, 2019-03)
      We introduce the family of trimmed serendipity finite element differential form spaces, defined on cubical meshes in any number of dimensions, for any polynomial degree, and for any form order. The relation between the trimmed serendipity family and the (non-trimmed) serendipity family developed by Arnold and Awanou [Math. Comp. 83 (2014), pp. 1551-1570] is analogous to the relation between the trimmed and (non-trimmed) polynomial finite element differential form families on simplicial meshes from finite element exterior calculus. We provide degrees of freedom in the general setting and prove that they are unisolvent for the trimmed serendipity spaces. The sequence of trimmed serendipity spaces with a fixed polynomial order r provides an explicit example of a system described by Christiansen and Gillette [ESAIM: M2AN 50 (2016), pp. 883-850], namely, a minimal compatible finite element system on squares or cubes containing order r - 1 polynomial differential forms.
    • Cardiac autonomic activity during simulated shift work

      SKORNYAKOV, Elena; GADDAMEEDHI, Shobhan; PAECH, Gemma M.; SPARROW, Amy R.; SATTERFIELD, Brieann C.; SHATTUCK, Nita L.; LAYTON, Matthew E.; KARATSOREOS, Ilia; VAN DONGEN, Hans P. A.; Univ Arizona, Social Cognit & Affect Neurosci Lab, Dept Psychiat, Coll Med (ELSEVIER GMBH, 2019-02)
      Shift work leads to adverse health outcomes including increased risk of cardiovascular disease. Heart rate (HR) and heart rate variability (HRV) arc measures of cardiac autonomic activity and markers of cardiovascular disease and mortality. To investigate the effects of shift work on cardiac autonomic activity, we assessed the influence of simulated night work on HR and HRV, and dissociated the direct effects of circadian misalignment from those of sleep displacement and altered physical activity patterns. A total of 29 subjects each participated in one of two in-laboratory, simulated shift work studies. In both studies, EKG was continuously monitored via Holter monitors to measure HR and the high frequency (HF) component of HRV (HF-HRV). We found endogenous circadian rhythmicity in HR and HF-HRV. Sleep and waking physical activity, both displaced during simulated night work, had more substantial, and opposite, effects on HR and HF-HRV. Our findings show systematic but complex, interacting effects of time of day, sleep/wake state, and physical activity on cardiac autonomic activity. These effects need to be taken into account when evaluating HR and HRV in shift work settings and when interpreting these measures of cardiac autonomic activity as markers of cardiovascular disease.
    • Soil exchange rates of COS and COO differ with the diversity of microbial communities and their carbonic anhydrase enzymes.

      Meredith, Laura K; Ogée, Jérôme; Boye, Kristin; Singer, Esther; Wingate, Lisa; von Sperber, Christian; Sengupta, Aditi; Whelan, Mary; Pang, Erin; Keiluweit, Marco; Brüggemann, Nicolas; Berry, Joe A; Welander, Paula V; Univ Arizona, Sch Nat Resources & Environm; Univ Arizona, Biosphere 2 (NATURE PUBLISHING GROUP, 2019-02-01)
      Differentiating the contributions of photosynthesis and respiration to the global carbon cycle is critical for improving predictive climate models. Carbonic anhydrase (CA) activity in leaves is responsible for the largest biosphere-atmosphere trace gas fluxes of carbonyl sulfide (COS) and the oxygen-18 isotopologue of carbon dioxide (CO
    • Lymphangiogenesis, lymphatic systemomics, and cancer: context, advances and unanswered questions.

      Dellinger, Michael T; Witte, Marlys H; Univ Arizona, Dept Surg, Coll Med (SPRINGER, 2018-08-01)
      Ever since it was discovered that endothelial cells line lymphatic vessels, investigators have been working on unraveling the mechanisms that control the growth of this distinctive endothelium and its role in normal physiology and human disease. Recent technological advances have ushered in a new era of "omics" research on the lymphatic system. Research on the genome, transcriptome, proteome, and metabolome of lymphatics has increased our understanding of the biology of the lymphatic vasculature. Here, we introduce the context-lymphatic "systemomics," then briefly review some of the latest advances in research on tumor-associated lymphatic vessels highlighting several "omic" studies that have shed light on mechanisms controlling the growth and function of tumor-associated lymphatic vessels. We conclude by returning, with unanswered questions, to the larger context of cancer and the lymphatic system as a vasculature, circulation, route of entry and transport, and control center of the immune network.
    • Singularity Analysis for Heavy-Tailed Random Variables

      Ercolani, Nicholas M.; Jansen, Sabine; Ueltschi, Daniel; Univ Arizona, Dept Math (SPRINGER/PLENUM PUBLISHERS, 2019-03)
      We propose a novel complex-analytic method for sums of i.i.d. random variables that are heavy-tailed and integer-valued. The method combines singularity analysis, Lindelof integrals, and bivariate saddle points. As an application, we prove three theorems on precise large and moderate deviations which provide a local variant of a result by Nagaev (Transactions of the sixth Prague conference on information theory, statistical decision functions, random processes, Academia, Prague, 1973). The theorems generalize five theorems by Nagaev (Litov Mat Sb 8:553-579, 1968) on stretched exponential laws p(k)=cexp(-k) and apply to logarithmic hazard functions cexp(-(logk)), >2; they cover the big-jump domain as well as the small steps domain. The analytic proof is complemented by clear probabilistic heuristics. Critical sequences are determined with a non-convex variational problem.
    • Driving behaviors associated with emergency service vehicle crashes in the U.S. fire service.

      Bui, D P; Hu, C; Jung, A M; Pollack Porter, K M; Griffin, S C; French, D D; Crothers, S; Burgess, J L; Univ Arizona, Dept Epidemiol & Biostat; Univ Arizona, Dept Community Environm & Policy (TAYLOR & FRANCIS INC, 2018-11-17)
      Emergency service vehicle incidents are a leading cause of firefighter fatalities and are also hazardous to civilian road users. Modifiable driving behaviors may be associated with emergency service vehicle incidents. The goal of this study was to use telematics to identify driving behaviors associated with crashes in the fire service. Forty-three emergency service vehicles in 2 fire departments were equipped with telematics devices (12 in Department A and 31 in Department B). The devices collected vehicle coordinates, speed, and g forces, which were monitored for exceptions to driving rules established by the fire departments regarding speeding, harsh braking, and hard cornering. Fire department administrative reports were used to identify vehicles involved in crashes and merged with daily telematics data. Penalized logistic regression was used to identify driving rules associated with crashes. Least absolute shrinkage and selection operator (LASSO) regression was used to generate a telematics-based risk index for emergency service vehicle incidents. Nearly 1.1 million km of driving data and 44 crashes were recorded among the 2 departments during the study. Harsh braking was associated with increased odds of crash in Department A (odds ratio [OR] = 2.22; 95% confidence interval [CI], 1.09-4.51) and Department B (OR = 1.55; 95% CI, 1.12-2.15). For every kilometer of nonemergency speeding, the odds of crash increased by 35% in Department A (OR = 1.35; 95% CI, 1.03-1.77) and by over 2-fold in Department B (OR = 2.09; 95% CI, 1.19-3.66). In Department B, hard cornering (OR = 1.14; 95% CI, 1.03-1.26) and emergency speeding (OR = 1.65; 95% CI, 1.06-2.57) were also associated with increased odds of crash. The final LASSO risk index model had a sensitivity of 73% and specificity of 57%. Harsh braking and excessive speeding were driving behaviors most associated with crash in the fire service. Telematics may be a useful tool for monitoring driver safety in the fire service.
    • Hardware-Based Probabilistic Threat Detection and Estimation for Embedded Systems

      Carreon, Nadir Amin; Lu, Sixing; Lysecky, Roman; Univ Arizona, Dept Elect & Comp Engn (IEEE, 2018)
      With billions of networked connected embedded systems, the security historically provided by the isolation of embedded systems is no longer sufficient. Both proactive security measures that prevent intrusions and reactive measures that detect intrusions are essential. Anomaly-based detection is a common reactive approach employed to detect malware that has evaded proactive defenses by observing anomalous deviations in the system execution. Timing-based anomaly detection detects malware by monitoring the system's internal timing, which offers unique protection against mimicry malware compared to sequence-based anomaly detection. However, previous timing-based anomaly detection methods focus on each operation independently at the granularity of tasks, function calls, system calls, or basic blocks. These approaches neither consider the entire software execution path nor provide a quantitative estimate of the presence of malware. This paper presents a novel model for specifying the normal timing for execution paths in software applications using cumulative distribution functions of timing data in sliding execution windows. We present a probabilistic formulation for estimating the presence of malware for individual operations and sequences of operations within the paths, and we define thresholds to minimize false positives based on training data. Experimental results with a smart connected pacemaker and three sophisticated mimicry malware demonstrate improved performance and accuracy compared to state-of-the-art timing-based malware detection.
    • Decentralized Control of Distributed Actuation in a Segmented Soft Robot Arm

      Doroudchi, Azadeh; Shivakumar, Sachin; Fisher, Rebecca E.; Marvi, Hamid; Aukes, Daniel; He, Ximin; Berman, Spring; Peet, Matthew M.; Univ Arizona, Coll Med Phoenix, Dept Basic Med Sci (IEEE, 2018)
      Continuum robot manipulators present challenges for controller design due to the complexity of their infinite-dimensional dynamics. This paper develops a practical dynamics-based approach to synthesizing state feedback controllers for a soft continuum robot arm composed of segments with local sensing, actuation, and control capabilities. Each segment communicates its states to its two adjacent neighboring segments, requiring a tridiagonal feedback matrix for decentralized controller implementation. A semi-discrete numerical approximation of the Euler-Bernoulli beam equation is used to represent the robot arm dynamics. Formulated in state space representation, this numerical approximation is used to define an H-infinity optimal control problem in terms of a Bilinear Matrix Inequality. We develop three iterative algorithms that solve this problem by computing the tridiagonal feedback matrix which minimizes the H-infinity norm of the map from disturbances to regulated outputs. We confirm through simulations that all three controllers successfully dampen the free vibrations of a cantilever beam that are induced by an initial sinusoidal displacement, and we compare the controllers' performance.
    • Unity and diversity of executive functions in creativity.

      Zabelina, Darya L; Friedman, Naomi P; Andrews-Hanna, Jessica; Univ Arizona (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2019-02-01)
      Increasing evidence suggests that executive functions (EFs) - a set of general-purpose control processes that regulate thoughts and behaviors - are relevant for creativity. However, EF is not a unitary process, and it remains unclear which specific EFs are involved. The present study examined the association between the three EFs, both uniquely (EF-Specific) and together (Common EF), and three measures of creativity. Participants (N = 47) completed a divergent thinking test, and self-reported their real-life creative accomplishments. A subset of participants indicated their involvement in the artistic or information technology (IT) professions. Results indicated that fluency (but not originality) of divergent thinking was uniquely predicted by working memory Updating. Better response Inhibition predicted higher number of real-world artistic creative achievements. Involvement in the artistic (versus IT) professions was associated with better Common EF, and with enhanced mental set Shifting abilities. Results demonstrate that different EFs predict creativity depending on its operational definition.
    • Genetic diversity and metapopulation structure of the brown swimming crab (Callinectes bellicosus) along the coast of Sonora, Mexico: Implications for fisheries management

      Cisneros-Mata, Miguel Ángel; Munguía-Vega, Adrián; Rodríguez-Félix, Demetrio; Aragón-Noriega, Eugenio Alberto; Grijalva-Chon, José Manuel; Arreola-Lizárraga, José Alfredo; Hurtado, Luis A.; Univ Arizona, Sch Nat Resources & Environm (ELSEVIER SCIENCE BV, 2019-04)
      Management of commercial fisheries resources is commonly done assuming that populations are spatially homogeneous throughout their geographic range. However, uneven gene flow can result in gradients of genetic diversity that can affect population dynamics and management reference points and may contribute to over-fishing. We examined whether the brown swimming crab, Callinectes bellicosus, fished along 1200 km on the coast of Sonora (Mexico) is a homogeneous population. Based on previous empirical evidence of differences in phenology, we hypothesized that C. bellicosus has a metapopulation structure which needs to be included in management tools. We conducted a genetic study of C. bellicosus taken at seven sites along the coast of Sonora and obtained their microsatellite genotypes. Recent gene flow, as well as the role of each site as source or sink, were investigated. We found a latitudinal gradient in genetic diversity and identified sites along the coast acting as sources or sinks of migrants. Central sites act as sources, while northern sites are sinks; the main source of migrants was the southern-most site. A predominantly asymmetric metapopulation structure composed of local populations with moderate connectivity may be explained by larval dispersal in the northward oceanic current during the spawning period. Including migration rates between sites in a metapopulation dynamics model of C. bellicosus and considering that fishing and management decisions in source populations will impact neighboring populations located downstream can improve current management of this important commercial fishery.
    • The reality of "food porn": Larger brain responses to food-related cues than to erotic images predict cue-induced eating

      Versace, Francesco; Frank, David W; Stevens, Elise M; Deweese, Menton M; Guindani, Michele; Schembre, Susan M; Univ Arizona, Dept Family & Community Med, Coll Med Tucson (WILEY, 2019-04-01)
      While some individuals can defy the lure of temptation, many others find appetizing food irresistible. The goal of this study was to investigate the neuropsychological mechanisms that increase individuals' vulnerability to cue-induced eating. Using ERPs, a direct measure of brain activity, we showed that individuals with larger late positive potentials in response to food-related cues than to erotic images are more susceptible to cue-induced eating and, in the presence of a palatable food option, eat more than twice as much as individuals with the opposite brain reactivity profile. By highlighting the presence of individual brain reactivity profiles associated with susceptibility to cue-induced eating, these findings contribute to the understanding of the neurobiological basis of vulnerability to obesity.
    • On Direct vs. Indirect Peer Influence in Large Social Networks

      Zhang, Bin; Pavlou, Paul; Ramayya, Krishnan; University of Arizona; Temple University; Carnegie Mellon University (Institute for Operations Research and the Management Sciences (INFORMS), 2018-06)
      With the availability of large-scale network data, peer influence in social networks can be more rigorously examined and understood than before. Peer influence can arise from immediate neighbors in the network (formally defined as cohesion or direct ties with one-hop neighbors) and from indirect peers who share common neighbors (formally defined as structural equivalence or indirect ties with two-hop neighbors). While the literature examined the role of each peer influence (direct or indirect) separately, the study of both peer network effects acting simultaneously was ignored, largely due to methodological constraints. This paper attempts to fill this gap by evaluating the simultaneous effect of both direct and indirect peer influences in technology adoption in the context of Caller Ring Back Tone (CRBT) in a cellular telephone network, using data from 200 million calls by 1.4 million users. Given that such a large-scale network makes traditional social network analysis intractable, we extract many densely-connected and self-contained subpopulations from the network. We find a regularity in these subpopulations in that they consist either of about 200 nodes or about 500 nodes. Using these sub-populations and panel data, we analyze direct and indirect peer influences using a novel auto-probit model with multiple network terms (direct and indirect peer influence, with homophily as a control variable). Our identification strategy relies on Bramoullé et al.’s (2009) spatial autoregressive model, allowing us to identify the direct and indirect peer influences on each of the extracted subpopulations. We use meta-analysis to summarize the estimated parameters from all subpopulations. The results show CRBT adoption to be simultaneously determined by both direct and indirect peer influence (while controlling for homophily and centrality). Robustness checks show model fit to improve when both peer influences are included. The size and direction of the two peer influences, however, differ by group size. Interestingly, indirect peer influence (structural equivalence) plays a negative role in diffusion when group size is about 200, but a positive role when group size is about 500. The role of direct peer influence (cohesion), on the other hand, is always positive, irrespective of group size. Our findings imply that businesses must design different target strategies for large versus small groups: for large groups, businesses should focus on consumers with both multiple one-hop and two-hop neighbors; for small groups, businesses should only focus on consumers with multiple one-hop neighbors.
    • Genetic determinants of risk in pulmonary arterial hypertension: international genome-wide association studies and meta-analysis

      Rhodes, Christopher J; Batai, Ken; Bleda, Marta; Haimel, Matthias; Southgate, Laura; Germain, Marine; Pauciulo, Michael W; Hadinnapola, Charaka; Aman, Jurjan; Girerd, Barbara; Arora, Amit; Knight, Jo; Hanscombe, Ken B; Karnes, Jason H; Kaakinen, Marika; Gall, Henning; Ulrich, Anna; Harbaum, Lars; Cebola, Inês; Ferrer, Jorge; Lutz, Katie; Swietlik, Emilia M; Ahmad, Ferhaan; Amouyel, Philippe; Archer, Stephen L; Argula, Rahul; Austin, Eric D; Badesch, David; Bakshi, Sahil; Barnett, Christopher; Benza, Raymond; Bhatt, Nitin; Bogaard, Harm J; Burger, Charles D; Chakinala, Murali; Church, Colin; Coghlan, John G; Condliffe, Robin; Corris, Paul A; Danesino, Cesare; Debette, Stéphanie; Elliott, C Gregory; Elwing, Jean; Eyries, Melanie; Fortin, Terry; Franke, Andre; Frantz, Robert P; Frost, Adaani; Garcia, Joe G N; Ghio, Stefano; Ghofrani, Hossein-Ardeschir; Gibbs, J Simon R; Harley, John; He, Hua; Hill, Nicholas S; Hirsch, Russel; Houweling, Arjan C; Howard, Luke S; Ivy, Dunbar; Kiely, David G; Klinger, James; Kovacs, Gabor; Lahm, Tim; Laudes, Matthias; Machado, Rajiv D; MacKenzie Ross, Robert V; Marsolo, Keith; Martin, Lisa J; Moledina, Shahin; Montani, David; Nathan, Steven D; Newnham, Michael; Olschewski, Andrea; Olschewski, Horst; Oudiz, Ronald J; Ouwehand, Willem H; Peacock, Andrew J; Pepke-Zaba, Joanna; Rehman, Zia; Robbins, Ivan; Roden, Dan M; Rosenzweig, Erika B; Saydain, Ghulam; Scelsi, Laura; Schilz, Robert; Seeger, Werner; Shaffer, Christian M; Simms, Robert W; Simon, Marc; Sitbon, Olivier; Suntharalingam, Jay; Tang, Haiyang; Tchourbanov, Alexander Y; Thenappan, Thenappan; Torres, Fernando; Toshner, Mark R; Treacy, Carmen M; Vonk Noordegraaf, Anton; Waisfisz, Quinten; Walsworth, Anna K; Walter, Robert E; Wharton, John; White, R James; Wilt, Jeffrey; Wort, Stephen J; Yung, Delphine; Lawrie, Allan; Humbert, Marc; Soubrier, Florent; Trégouët, David-Alexandre; Prokopenko, Inga; Kittles, Richard; Gräf, Stefan; Nichols, William C; Trembath, Richard C; Desai, Ankit A; Morrell, Nicholas W; Wilkins, Martin R; Univ Arizona, Dept Surg, Div Urol, Coll Med; Univ Arizona, Coll Med, Sarver Heart Ctr, Dept Pharm Practice & Sci, Coll Pharm; Univ Arizona, Ctr Appl Genet & Genom Med TCAG2M, Coll Med; Univ Arizona, Dept Med; Univ Arizona, Arizona Hlth Sci Ctr (ELSEVIER SCI LTD, 2019-03-01)
      Rare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes. We did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses. A locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55-2·08], p=5·13 × 10 This is the first study to report that common genetic variation at loci in an enhancer near SOX17 and in HLA-DPA1/DPB1 is associated with pulmonary arterial hypertension. Impairment of SOX17 function might be more common in pulmonary arterial hypertension than suggested by rare mutations in SOX17. Further studies are needed to confirm the association between HLA typing or rs2856830 genotyping and survival, and to determine whether HLA typing or rs2856830 genotyping improves risk stratification in clinical practice or trials.
    • Recent Advances in Non-invasive Processing Schemes on Electrocardiogram (ECG): a Review

      Gao, Xin; Univ Arizona, Dept Elect & Comp Engn (Internal Medicine Review, 2018-06)
      Non-invasive processing schemes on electrocardiogram (ECG) especially fetal ECG, represent technical advantages such as cohesive monitoring, explicit signaling and imaging, free of uterus infection comparing to traditional invasive methods. We concisely summarize the recent progress of methods in non-invasive detection and compression on ECG, then categorize the crucial sample datasets and major types of experimental design in the review sections. Algorithms and implementation of test platform on compression of ECG data and fetal health monitoring in practical systems design are simultaneously studied therein. Our study specifies that recent advances in this area lie in sparse representation, variable filtering techniques, multi-resolution feature extraction and a few other joint schemes. We also sketch a framework of portable system design on fetal ECG monitoring with specific choice on the elements of hardware configuration in the discussion section.
    • Estimating Contextual Motivating Factors in Virtual Interorganizational Communities of Practice: Peer Effects and Organizational Influences

      Zhao, Kexin; Zhang, Bin; Bai, Xue; Univ Arizona, Eller Coll Management, Dept Management Informat Syst (Institute for Operations Research and the Management Sciences (INFORMS), 2018-12)
      Virtual inter-organizational communities of practice (IOCoPs) enable professionals belonging to different organizations to exchange and share knowledge via computer-mediated interactions. Since knowledge sharing is socially embedded, contextual factors likely play an important role in encouraging individuals’ community participation. Specifically, professionals in IOCoPs are embedded in two different social environments: the virtual community where they interact with online peers and organizations where they utilize their knowledge. Therefore it is important to simultaneously study motivating factors generated from these two different contexts, including peer effects within and organizational influences outside the virtual community. In this research, we apply a novel econometric identification method to analyze a unique dataset collected from a virtual IOCoP in the financial trading sector. We find that, after controlling for individual level characteristics, contextual motivating factors from peers and organizations are influential both quantitatively and qualitatively in determining community participation. Differentiating multiple-level motivating factors across different contexts enables us to shed light on various mechanisms that IOCoPs can apply to engage collective learning and knowledge management across organizations.
    • Broadband extended source imaging Mueller-matrix polarimeter

      López-Téllez, Juan Manuel; Chipman, Russell A.; Li, Lisa W.; McEldowney, Scott C.; Smith, Matthew H.; Univ Arizona, Coll Opt Sci (OPTICAL SOC AMER, 2019-04-01)
      An imaging Mueller matrix polarimeter, named the red–green–blue (RGB)950, takes images of medium-sized (tens of centimeters) objects by using a very bright source, large polarization state generator, and high-quality camera. Its broadband extended light source switches between red, green, blue, and near-infrared light to allow taking polarimetric images for comparison with RGB camera images. The large diffuse source makes shadow transitions gradual and spreads out the specular reflected spot into a larger less conspicuous area.
    • Data Science Support at the Academic Library

      Oliver, Jeffrey C.; Kollen, Christine; Hickson, Benjamin; Rios, Fernando; Office of Digital Innovation and Stewardship, University Libraries, University of Arizona (Taylor & Francis Group, 2019-03-20)
      Data science is a rapidly growing field with applications across all scientific domains. The demand for support in data science literacy is outpacing available resources at college campuses. The academic library is uniquely positioned to provide training and guidance in a number of areas relevant to data science. The University of Arizona Libraries has built a successful data science support program, focusing on computational literacy, geographic information systems, and reproducible science. Success of the program has largely been due to the strength of library personnel and strategic partnerships with units outside of the library. Academic libraries can support campus data science needs through professional development of current staff and recruitment of new personnel with expertise in data-intensive domains.