Now showing items 2493-2512 of 13150

    • Crossing minimization in perturbed drawings

      Fulek, Radoslav; Tóth, Csaba D.; Univ Arizona (SPRINGER, 2020-06-12)
      Due to data compression or low resolution, nearby vertices and edges of a graph drawn in the plane may be bundled to a common node or arc. We model such a "compromised" drawing by a piecewise linear map phi:G -> R-2. We wish to perturb phi by an arbitrarily small epsilon>0 into a proper drawing (in which the vertices are distinct points, any two edges intersect in finitely many points, and no three edges have a common interior point) that minimizes the number of crossings. An epsilon-perturbation, for every epsilon>0, is given by a piecewise linear map psi epsilon:G -> R-2 with ||phi-psi epsilon||<epsilon is the uniform norm (i.e.,supnorm). We present a polynomial-time solution for this optimization problem whenGis a cycle and the map phi has nospurs(i.e., no two adjacent edges are mapped to overlapping arcs). We also show that the problem becomes NP-complete (i) whenGis an arbitrary graph and phi has no spurs, and (ii) when phi may have spurs andGis a cycle or a union of disjoint paths.
    • Crosslinguistic evidence for a strong statistical universal: Phonological neutralization targets word-ends over beginnings

      Wedel, Andrew B; Ussishkin, Adam; King, Adam; Univ Arizona (LINGUISTIC SOC AMER, 2019-12-04)
      We report a statistical test of a long-standing hypothesis in the literature: that phonological neutralization rules are more common at the ends of lexical domains than the beginnings (Houlihan 1975 et seq.). We collected descriptive grammars for an areally and genetically diverse set of fifty languages, identified all active phonological rules that target the edge of a lexical domain (root, stem, word, phrase or utterance), and further coded each rule for whether it was phonemically neutralizing, that is, able to create surface homophony. We find that such neutralizing rules are strongly, significantly less common at the beginning of lexical domains relative to ends, and that this pattern is strikingly consistent across all languages within the dataset. We show that this pattern is not an artifact of a tendency for syllable codas to be a target for phonological neutralization, nor is associated with a suffixing or prefixing preference. Consistent with previous accounts, we argue that this pattern may be ultimately based in the greater average information content of phonological categories early in the word, which itself is a consequence of incremental processing in lexical access.
    • Crucial Genes in Aortic Dissection Identified by Weighted Gene Coexpression Network Analysis

      Zhang, H.; Chen, T.; Zhang, Y.; Lin, J.; Zhao, W.; Shi, Y.; Lau, H.; Zhang, Y.; Yang, M.; Xu, C.; et al. (Hindawi Limited, 2022)
      Background. Aortic dissection (AD) is a lethal vascular disease with high mortality and morbidity. Though AD clinical pathology is well understood, its molecular mechanisms remain unclear. Specifically, gene expression profiling helps illustrate the potential mechanism of aortic dissection in terms of gene regulation and its modification by risk factors. This study was aimed at identifying the genes and molecular mechanisms in aortic dissection through bioinformatics analysis. Method. Nine patients with AD and 10 healthy controls were enrolled. The gene expression in peripheral mononuclear cells was profiled through next-generation RNA sequencing. Analyses including differential expressed gene (DEG) via DEGseq, weighted gene coexpression network (WGCNA), and VisANT were performed to identify crucial genes associated with AD. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was also utilized to analyze Gene Ontology (GO). Results. DEG analysis revealed that 1,113 genes were associated with AD. Of these, 812 genes were markedly reduced, whereas 301 genes were highly expressed, in AD patients. DEGs were rich in certain categories such as MHC class II receptor activity, MHC class II protein complex, and immune response genes. Gene coexpression networks via WGCNA identified 3 gene hub modules, with one positively and 2 negatively correlated with AD, respectively. Specifically, module 37 was the most strongly positively correlated with AD with a correlation coefficient of 0.72. Within module 37, five hub genes (AGFG1, MCEMP1, IRAK3, KCNE1, and CLEC4D) displayed high connectivity and may have clinical significance in the pathogenesis of AD. Conclusion. Our analysis provides the possible association of specific genes and gene modules for the involvement of the immune system in aortic dissection. AGFG1, MCEMP1, IRAK3, KCNE1, and CLEC4D in module M37 were highly connected and strongly linked with AD, suggesting that these genes may help understand the pathogenesis of aortic dissection. © 2022 Hongliang Zhang et al.
    • Crustal Groundwater Volumes Greater Than Previously Thought

      Ferguson, G.; McIntosh, J.C.; Warr, O.; Sherwood Lollar, B.; Ballentine, C.J.; Famiglietti, J.S.; Kim, J.-H.; Michalski, J.R.; Mustard, J.F.; Tarnas, J.; et al. (John Wiley and Sons Inc, 2021)
      Global groundwater volumes in the upper 2 km of the Earth's continental crust—critical for water security—are well estimated. Beyond these depths, a vast body of largely saline and non-potable groundwater exists down to at least 10 km—a volume that has not yet been quantified reliably at the global scale. Here, we estimate the amount of groundwater present in the upper 10 km of the Earth's continental crust by examining the distribution of sedimentary and crystalline rocks with depth and applying porosity-depth relationships. We demonstrate that groundwater in the 2–10 km zone (what we call “deep groundwater”) has a volume comparable to that of groundwater in the upper 2 km of the Earth's crust. These new estimates make groundwater the largest continental reservoir of water, ahead of ice sheets, provide a basis to quantify geochemical cycles, and constrain the potential for large-scale isolation of waste fluids. © 2021. American Geophysical Union. All Rights Reserved.
    • Crustal structure across the eastern North American margin from ambient noise tomography

      Lynner, Colton; Porritt, Robert W.; Univ Arizona, Dept Geosci; Department of Geosciences; University of Arizona; Tucson Arizona USA; Department of Geosciences; University of Arizona; Tucson Arizona USA (AMER GEOPHYSICAL UNION, 2017-07-16)
      Passive tectonic margins, like the eastern North American margin (ENAM), represent the meeting of oceanic and continental material where no active deformation is occurring. The recent ENAM Community Seismic Experiment provides an opportunity to examine the crustal structure across the ENAM owing to the simultaneous deployment of offshore and onshore seismic instrumentation. Using Rayleigh wave phase and group velocities derived from ambient noise data, we invert for shear velocity across the ENAM. We observe a region of transitional crustal thicknesses that connects the oceanic and continental crusts. Associated with the transitional crust is a localized positive gravitational anomaly. Farther east, the East Coast magnetic anomaly (ECMA) is located at the intersection of the transitional and oceanic crusts. We propose that underplating of dense magmatic material along the bottom of the transitional crust is responsible for the gravitational anomaly and that the ECMA demarks the location of initial oceanic crustal formation.
    • Crustal structure of north Peru from analysis of teleseismic receiver functions

      Condori, Cristobal; França, George S.; Tavera, Hernando J.; Albuquerque, Diogo F.; Bishop, Brandon T.; Beck, Susan L.; University of Arizona UA, Department of Geosciences (PERGAMON-ELSEVIER SCIENCE LTD, 2017-07)
      In this study, we present results from teleseismic receiver functions, in order to investigate the crustal thickness and Vp/Vs ratio beneath northern Peru. A total number of 981 receiver functions were analyzed, from data recorded by 28 broadband seismic stations from the Peruvian permanent seismic network, the regional temporary SisNort network and one CTBTO station. The Moho depth and average crustal Vp/Vs ratio were determined at each station using the H-k stacking technique to identify the arrival times of primary P to S conversion and crustal reverberations (PpPms, PpSs + PsPms). The results show that the Moho depth correlates well with the surface topography and varies significantly from west to east, showing a shallow depth of around 25 km near the coast, a maximum depth of 55-60 km beneath the Andean Cordillera, and a depth of 35-40 km further to the east in the Amazonian Basin. The bulk crustal Vp/Vs ratio ranges between 1.60 and 1.88 with the mean of 1.75. Higher values between 1.75 and 1.88 are found beneath the Eastern and Western Cordilleras, consistent with a mafic composition in the lower crust. In contrast values vary from 1.60 to 1.75 in the extreme flanks of the Eastern and Western Cordillera indicating a felsic composition. We find a positive relationship between crustal thickness, Vp/ Vs ratio, the Bouguer anomaly, and topography. These results are consistent with previous studies in other parts of Peru (central and southern regions) and provide the first crustal thickness estimates for the high cordillera in northern Peru.
    • Cryo-EM structure of arabinosyltransferase EmbB from Mycobacterium smegmatis

      Tan, Yong Zi; Rodrigues, José; Keener, James E; Zheng, Ruixiang Blake; Brunton, Richard; Kloss, Brian; Giacometti, Sabrina I; Rosário, Ana L; zhang, Lei; Niederweis, Michael; et al. (NATURE PUBLISHING GROUP, 2020-07-07)
      Arabinosyltransferase B (EmbB) belongs to a family of membrane-bound glycosyl-transferases that build the lipidated polysaccharides of the mycobacterial cell envelope, and are targets of anti-tuberculosis drug ethambutol. We present the 3.3 angstrom resolution single-particle cryo-electron microscopy structure of Mycobacterium smegmatis EmbB, providing insights on substrate binding and reaction mechanism. Mutations that confer ethambutol resistance map mostly around the putative active site, suggesting this to be the location of drug binding.
    • Cryogenic C-band wavelength division multiplexing system using an AIM Photonics Foundry process design kit

      Fard, E.M.; Long, C.M.; Lentine, A.L.; Norwood, R.A.; College of Optical Sciences, University of Arizona (OSA - The Optical Society, 2020)
      Cryogenic environments make superconducting computing possible by reducing thermal noise, electrical resistance and heat dissipation. Heat generated by the electronics and thermal conductivity of electrical transmission lines to the outside world constitute two main sources of thermal load in such systems. As a result, higher data rates require additional transmission lines which come at an increasingly higher cooling power cost. Hybrid or monolithic integration of silicon photonics with the electronics can be the key to higher data rates and lower power costs in these systems. We present a 4-channel wavelength division multiplexing photonic integrated circuit (PIC) built from modulators in the AIM Photonics process development kit (PDK) that operate at 25 Gbps at room temperature and 10 Gbps at 40 K. We further demonstrate 2-channel operation for 20 Gbps aggregate data rate at 40 K using two different modulators/wavelengths, with the potential for higher aggregate bit rates by utilizing additional channels. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
    • Crystal alignment of a LiNi0.5Mn0.3Co0.2O2 electrode material for lithium ion batteries using its magnetic properties

      Kim, Cham; Yang, Yeokyung; Lopez, David Humberto; Ha, Dongwoo; Univ Arizona, Dept Chem & Environm Engn (AMER INST PHYSICS, 2020-09-22)
      We studied technology that enables the crystal alignment of LiNi0.5Mn0.3Co0.2O2 using its magnetic properties. LiNi0.5Mn0.3Co0.2O2 exhibited either antiferromagnetic or paramagnetic behavior depending on temperature as well as magnetic anisotropy originated from its crystallographic anisotropy. Based on these magnetic characteristics, we adjusted the vector quantity of an external magnetic field and applied it to LiNi0.5Mn0.3Co0.2O2 crystals, thus producing crystal-aligned LiNi0.5Mn0.3Co0.2O2 electrodes. In these electrodes, the (001) plane was oriented comparatively perpendicular to the surface of a current collector. Due to the intrinsic lithium ion transport kinetics in LiNi0.5Mn0.3Co0.2O2 along the (001) plane, aligned LiNi0.5Mn0.3Co0.2O2 may contribute to enhancing lithium ion conduction during the charge/discharge process in a lithium ion battery, resulting in improved electrochemical performance. Published under license by AIP Publishing.
    • Crystalline aspects of geography of low dimensional varieties I: numerology

      Joshi, Kirti; Univ Arizona, Dept Math (SPRINGER INTERNATIONAL PUBLISHING AG, 2020-08-06)
      This is a modest attempt to study, in a systematic manner, the structure of low dimensional varieties in positive characteristics using p-adic invariants. The main objects of interest in this paper are surfaces and threefolds. There are many results we prove in this paper and not all can be listed in this abstract. Here are some of the results. We prove inequalities related to the Bogomolov-Miyaoka-Yau inequality: in Corollary 4.7 that c(1)(2) <= max(5c(2) + 6b(1), 6c(2)) holds for a large class of surfaces of general type. In Theorem 4.17 we prove that for a smooth, projective, Hodge-Witt, minimal surface of general type (with additional assumptions such as slopes of Frobenius on H-cris(2) (X) are >= 1/2) that c(1)(2) <= 5c(2). We do not assume any lifting, and novelty of our method lies in our use of slopes of Frobenius and the slope spectral sequence. We also construct new birational invariants of surfaces. Applying our methods to threefolds, we characterize Calabi-Yau threefolds with b(3) = 0. We show that for any CalabiYau threefold b(2) >= c(3)/2 - 1 and that threefolds which lie on the line b(2) = c(3)/2 - 1 are precisely those with b(3) = 0 and threefolds with b(2) = c(3)/2 are characterized as Hodge-Witt rigid (included are rigid Calabi-Yau threefolds which have torsion-free crystalline cohomology and whose Hodge-de Rham spectral sequence degenerates).
    • CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion

      Haffert, S. Y.; van Holstein, R. G.; Ginski, C.; Brinchmann, J.; Snellen, I. A. G.; Milli, J.; Stolker, T.; Keller, C. U.; Girard, J.; Univ Arizona, Steward Observ (EDP SCIENCES S A, 2020-08)
      Context. Direct imaging provides a steady flow of newly discovered giant planets and brown dwarf companions. These multi-object systems can provide information about the formation of low-mass companions in wide orbits and/or help us to speculate about possible migration scenarios. Accurate classification of companions is crucial for testing formation pathways.Aims. In this work we further characterise the recently discovered candidate for a planetary-mass companion CS Cha b and determine if it is still accreting.Methods. MUSE is a four-laser-adaptive-optics-assisted medium-resolution integral-field spectrograph in the optical part of the spectrum. We observed the CS Cha system to obtain the first spectrum of CS Cha b. The companion is characterised by modelling both the spectrum from 6300 angstrom to 9300 angstrom and the photometry using archival data from the visible to the near-infrared (NIR).Results. We find evidence of accretion and outflow signatures in H alpha and OI emission. The atmospheric models with the highest likelihood indicate an effective temperature of 345050 K with a log g of 3.6 +/- 0.5 dex. Based on evolutionary models, we find that the majority of the object is obscured. We determine the mass of the faint companion with several methods to be between 0.07 M-circle dot and 0.71 M-circle dot with an accretion rate of M = 4 x 10(-11 +/- 0.4)M(circle dot) yr(-1).Conclusions. Our results show that CS Cha B is most likely a mid-M-type star that is obscured by a highly inclined disc, which has led to its previous classification using broadband NIR photometry as a planetary-mass companion. This shows that it is important and necessary to observe over a broad spectral range to constrain the nature of faint companions.
    • CUDA-OpenGL GPU-based real time beam tracking by MEMS phase SLM

      Tang, C.-I.; Deng, X.; Takashima, Y.; James C. Wyant College of Optical Sciences, University of Arizona (SPIE, 2022)
      CUDA-OpenGL interoperability enables to drastically reduce the computational time for CGH calculation and display on Spatial Light Modulators via HDMI display channel. The fast calculation method enables on-the-fly diffractive beam steering by Micro Electro Mechanical System based phase light modulator with YOLOv4-tiny model based object recognition to do AI-based dynamic beam tracking in order to trace the object of interest. © 2022 SPIE
    • CUILESS2016: a clinical corpus applying compositional normalization of text mentions

      Osborne, John D.; Neu, Matthew B.; Danila, Maria I.; Solorio, Thamar; Bethard, Steven J.; Univ Arizona, Sch Informat (BIOMED CENTRAL LTD, 2018-01-10)
      Background: Traditionally text mention normalization corpora have normalized concepts to single ontology identifiers ("pre-coordinated concepts"). Less frequently, normalization corpora have used concepts with multiple identifiers ("post-coordinated concepts") but the additional identifiers have been restricted to a defined set of relationships to the core concept. This approach limits the ability of the normalization process to express semantic meaning. We generated a freely available corpus using post-coordinated concepts without a defined set of relationships that we term "compositional concepts" to evaluate their use in clinical text. Methods: We annotated 5397 disorder mentions from the ShARe corpus to SNOMED CT that were previously normalized as "CUI-less" in the "SemEval-2015 Task 14" shared task because they lacked a pre-coordinated mapping. Unlike the previous normalization method, we do not restrict concept mappings to a particular set of the Unified Medical Language System (UMLS) semantic types and allow normalization to occur to multiple UMLS Concept Unique Identifiers (CUIs). We computed annotator agreement and assessed semantic coverage with this method. Results: We generated the largest clinical text normalization corpus to date with mappings to multiple identifiers and made it freely available. All but 8 of the 5397 disorder mentions were normalized using this methodology. Annotator agreement ranged from 52.4% using the strictest metric (exact matching) to 78.2% using a hierarchical agreement that measures the overlap of shared ancestral nodes. Conclusion: Our results provide evidence that compositional concepts can increase semantic coverage in clinical text. To our knowledge we provide the first freely available corpus of compositional concept annotation in clinical text.
    • Cul4 ubiquitin ligase cofactor DCAF12 promotes neurotransmitter release and homeostatic plasticity

      Patrón, Lilian A; Nagatomo, Kei; Eves, David Tyler; Imad, Mays; Young, Kimberly; Torvund, Meaghan; Guo, Xiufang; Rogers, Gregory C; Zinsmaier, Konrad E; Univ Arizona, Dept Neurosci; et al. (ROCKEFELLER UNIV PRESS, 2019-03-04)
      We genetically characterized the synaptic role of the Drosophila homologue of human DCAF12, a putative cofactor of Cullin4 (Cul4) ubiquitin ligase complexes. Deletion of Drosophila DCAF12 impairs larval locomotion and arrests development. At larval neuromuscular junctions (NMJs), DCAF12 is expressed presynaptically in synaptic boutons, axons, and nuclei of motor neurons. Postsynaptically, DCAF12 is expressed in muscle nuclei and facilitates Cul4-dependent ubiquitination. Genetic experiments identified several mechanistically independent functions of DCAF12 at larval NMJs. First, presynaptic DCAF12 promotes evoked neurotransmitter release. Second, postsynaptic DCAF12 negatively controls the synaptic levels of the glutamate receptor subunits GluRIIA, GluRIIC, and GluRIID. The down-regulation of synaptic GluRIIA subunits by nuclear DCAF12 requires Cul4. Third, presynaptic DCAF12 is required for the expression of synaptic homeostatic potentiation. We suggest that DCAF12 and Cul4 are critical for normal synaptic function and plasticity at larval NMJs.
    • Cultivating circular economies in the gaps of governance: lessons from Lebanon’s ecosystem of CE micro projects

      Rosenbaum, Rachel Ann; Kehdy, Joslin Faith; School of Anthropology, The University of Arizona (Informa UK Limited, 2022-02-25)
      This article explores micro circular economies (CEs) in Lebanon. The researchers asked, “What do CEs that center human health, equity, and well-being into their design look like in practice? What lessons can macro-CE projects and policy learn from such approaches?” Employing a political ecology framework, the authors assess the socio-political conditions through which these CEs emerged to understand the possibilities for mobilising CEs as solutions for conditions of systemic violence and inequality. Analysing common discourses and practices across disparate CE micro projects, this article theorises the main differences between such projects and institutionalised or corporate CEs. This study traces CEs which emerged during the garbage crisis of 2015 and coalesced during the thawra (the 2019–2020 uprisings in Lebanon). The authors analyse the challenges, opportunities, and lessons learned in navigating multifaceted CE projects within these challenging conditions. Through examining circular economy solutions “from below”, we argue that CE projects that are designed to respond to histories of power and inequality have greater potential to advance socio-ecological equality by creating innovative models for resource (re)use and distribution.
    • Cultivating Crisis: Coffee, Smallholder Vulnerability, and the Uneven Sociomaterial Consequences of the Leaf Rust Epidemic in Jamaica

      Rhiney, Kevon; Knudson, Chris; Guido, Zack; Univ Arizona, Arizona Inst Resilience; Univ Arizona, Sch Nat Resources & Environm (Informa UK Limited, 2020-08-14)
      Since September 2012, the Jamaican coffee industry has been grappling with the coffee leaf rust (CLR) epidemic caused by the fungal pathogen Hemileia vastatrix. The first widespread outbreak affected more than one third of coffee plants across the island, resulting in millions of dollars in lost revenues for the sector. The emergence and spread of the disease have been linked to a confluence of factors ranging from changing climatic conditions to impacts from extreme weather events, improper farm management practices, and institutional and market constraints that restrict control measures. In this article, we use the case of the CLR epidemic to illustrate how its emergence and continued presence in the Jamaican Blue Mountains is inextricably tied to the wider political-economic and ecological conditions under which coffee production takes place and how H. vastatrix's complex pathogenesis makes the disease difficult to control. Drawing on an empirical study comprising household surveys, focus groups, archival research, and interviews, we demonstrate how smallholder farmers' ability to manage rust impacts was severely compromised by ecological pressures, resource constraints, bounded knowledge systems, and market and regulatory limitations.
    • Cultural considerations for the adaptation of a diabetes self-management education program in Cotonou, Benin: Lessons learned from a qualitative study

      Alaofè, H.; Yeo, S.; Okechukwu, A.; Magrath, P.; Hounkpatin, W.A.; Ehiri, J.; Rosales, C.; Department of Health Promotion Sciences, Mel and Enid Zuckerman College of Public Health, University of Arizona; Division of Public Health Practice & Translational Research, University of Arizona (MDPI AG, 2021)
      Background: Type 2 diabetes (T2D) poses a disproportionate burden on Benin, West Africa. However, no diabetes intervention has yet been developed for Benin’s contexts. This study aimed to explore specific cultural beliefs, attitudes, behaviors, and environmental factors to help adapt a diabetes self-management program to patients with T2D from Cotonou, in southern Benin. Methods: Qualitative data were collected through focus group discussions (FDGs) involving 32 patients with T2D, 16 academic partners, and 12 community partners. The FDGs were audio-recorded, transcribed verbatim from French to English, and then analyzed thematically with MAXQDA 2020. Results: Healthy food was challenging to obtain due to costs, seasonality, and distance from markets. Other issues discussed were fruits and vegetables as commodities for the poor, perceptions and stigmas surrounding the disease, and the financial burden of medical equipment and treatment. Information about local food selections and recipes as well as social support, particularly for physical activity, were identified, among other needs. When adapting the curriculum, gender dynamics and spirituality were suggested. Conclusions: The study demonstrates the need for culturally sensitive interventions and a motivation-based approach to health (spiritual and emotional support). It also lays the groundwork for addressing T2D contextually in Benin and similar sub-Saharan African countries. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
    • Culturally Grounded Scapegoating in Response to Illness and the COVID-19 Pandemic

      Yang, Q.; Young, I.F.; Wan, J.; Sullivan, D.; University of Arizona (Frontiers Media S.A., 2021)
      For years, violence against doctors and healthcare workers has been a growing social issue in China. In a recent series of studies, we provided evidence for a motivated scapegoating account of this violence. Specifically, individuals who feel that the course of their (or their family member's) illness is a threat to their sense of control are more likely to express motivation to aggress against healthcare providers. Drawing on existential theory, we propose that blaming and aggressing against a single individual represents a culturally afforded scapegoating mechanism in China. However, in an era of healthcare crisis (i.e., the global COVID-19 pandemic), it is essential to understand cultural variation in scapegoating in the context of healthcare. We therefore undertook two cross-cultural studies examining how people in the United States and China use different scapegoating responses to re-assert a sense of control during medical uncertainty. One study was conducted prior to the pandemic and allowed us to make an initial validating and exploratory investigation of the constructs of interest. The second study, conducted during the pandemic, was confirmatory and investigated mediation path models. Across the two studies, consistent evidence emerged that, both in response to COVID-related and non-COVID-related illness scenarios, Chinese (relative to U.S.) individuals are more likely to respond by aggressing against an individual doctor, while U.S. (relative to Chinese) individuals are more likely to respond by scapegoating the medical industry/system. Further, Study 2 suggests these culture effects are mediated by differential patterns of primary and secondary control-seeking. © Copyright © 2021 Yang, Young, Wan and Sullivan.
    • Culturally Responsive Assessment of Life Science Skills and Abilities: Development, Field Testing, Implementation, and Results

      Zimmerman, Robert H.; Maker, C. June; Alfaiz, Fahad; Univ Arizona, Dept Disabil & Psychoeducat Studies; Univ Arizona (SAGE Publications, 2020-06-03)
      A research team consisting of educators of gifted students, a scientist, and experts in measurement developed a performance-based assessment of life science skills and abilities. Four high schools in the Southwestern United States were the settings for field testing and implementation. Five levels of ratings were given: unknown, maybe, probably, definitely, and wow. The majority of student scores were in the maybe and probably categories. Using six new measures (concept maps in life and physical science, math problem solving, spatial analytical performance assessment, life science performance assessment and physical science performance assessment), 23 students (M2) were selected for participation in science laboratories at an R1 university along with 20 students (M1) selected by conventional means. When the nine attribute scores of the performance-based assessment were compared, no significant difference was found t(41), p > .38, between M1 and M2 students. Performance-based assessments in science, technology, engineering, and mathematics (STEM) will provide an alternative and a complement to standard achievement tests. They have the potential to identify and nurture exceptionally talented high school students across all demographic groups.
    • Culturally Responsive Assessment of Physical Science Skills and Abilities: Development, Field Testing, Implementation, and Results

      Alfaiz, Fahad S.; Pease, Randy; Maker, C. June; Univ Arizona, Dept Disabil & Psychoeduc Studies (SAGE Publications, 2020-06-02)
      During the Cultivating Diverse Talent in STEM (CDTIS) Project, a team of scientists, teachers, and a researcher developed a performance-based assessment of high school students' creative problem-solving skills and ability to apply physical science principles in practical ways. It was one of six measures to identify exceptionally talented students. Students identified using conventional methods (M1), with an average grade point average (GPA) of 3.93, had an average rating of 2.95 on a 5-point scale on the mechanical-technical assessment. The M2 students, who were from schools with high percentages of Hispanic, American Indian, and low socioeconomic status (SES) students, had an average GPA of 3.07 and an average rating of 3.27, demonstrating that this assessment can be an important way to change the cultural and economic balance of students identified as exceptionally talented in Science, Technology, Engineering, and Mathematics (STEM). Other researchers are encouraged to examine the validity of the mechanical-technical assessment to identify exceptionally talented students in different groups.