University of Alabama
  • Tuscaloosa, Alabama, United States
Recent publications
Background This implementation feasibility study was conducted to determine whether an evidence-based parent-implemented distance-learning intervention model for young children at high likelihood of having ASD could be implemented at fidelity by Part C community providers and by parents in low-resource communities. Methods The study used a community-academic partnership model to adapt an evidence-based intervention tested in the current pilot trial involving randomization by agency in four states and enrollment of 35 coaches and 34 parent-family dyads. After baseline data were gathered, providers in the experimental group received 12–15 h of training while control providers received six webinars on early development. Providers delivered 6 months of intervention with children-families, concluding with data collection. Regression analyses were used to model outcomes of the coach behaviors, the parent fidelity ratings, and child outcomes. Results A block design model-building approach was used to test the null model followed by the inclusion of group as a predictor, and finally the inclusion of the planned covariates. Model fit was examined using changes in R ² and F -statistic. As hypothesized, results demonstrated significant gains in (1) experimental provider fidelity of coaching implementation compared to the control group; and (2) experimental parent fidelity of implementation compared to the control group. There were no significant differences between groups on child developmental scores. Conclusions Even though the experimental parent group averaged less than 30 min of intervention weekly with providers in the 6 months, both providers and parents demonstrated statistically significant gains on the fidelity of implementation scores with moderate effect sizes compared to control groups. Since child changes in parent-mediated models are dependent upon the parents’ ability to deliver the intervention, and since parent delivery is dependent upon providers who are coaching the parents, these results demonstrated that two of these three links of the chain were positively affected by the experimental implementation model. However, a lack of significant differences in child group gains suggests that further work is needed on this model. Factors to consider include the amount of contact with the provider, the amount of practice children experience, the amount of contact both providers and parents spend on training materials, and motivational strategies for parents, among others. Trial registration Registry of Efficacy and Effectiveness Studies: #4360, registered 1xx, October, 2020 – Retrospectively registered,
This special edition is based on the revelation that “the lessons learned and unlearned during COVID-19 grant us an unparalleled opportunity to reflect.” Here, we reflect on lessons learned related to teacher adaptiveness. We examined how the COVID-19 pandemic demonstrated the adaptiveness necessary for teachers to knowledge generation approaches aligned with the Next Generation Science Standards. First, we outline a three-year professional development program focused on knowledge generation approaches. We present findings from teachers’ experiences teaching science from 2019 to 2021, collected through consecutive form explanatory mixed-methods analysis involving written responses to vignettes ( n = 474) and classroom observations ( n = 58). Then, using an individual teacher case study, we explore how the shift to virtual teaching was supported by adaptiveness. Results suggest a significant relationship between teacher adaptiveness and the use of knowledge generation approaches. We conclude with implications for elementary science teacher professional development and present questions for further research on adaptiveness.
This study contributes to efforts towards creating livable communities, by identifying and proposing countermeasures for factors that are associated with residential area crashes. Three risky driving pre-crash actions: driving under the influence of alcohol or drug, aggressive driving, and speeding were considered. The study used residential area crash data from Alabama, USA and developed a latent class multinomial logit model to identify factors associated with the pre-crash actions. The results showed that male drivers had 0.44% and 2.09% higher chances to be at fault in driving under the influence of alcohol or drug and aggressive driving crashes, respectively, while female drivers were found to have a 1.82% higher likelihood to be at fault in speeding-related crashes but less likely to be at fault in aggressive driving or driving under the influence of alcohol or drug-related crashes in residential areas. Speeding and driving under the influence of were found to be the leading contributing factors in rural area residential crashes whereas aggressive driving was more pronounced in urban areas. These findings provide a basis for the implementation of appropriate crash countermeasures to reduce residential area crashes, as part of efforts geared towards promoting community safety and livability across the state.
Biofouling is a pivotal problem for polymeric membranes used in water treatment and reuse. Surface functionalization is a promising practice to improve the resistance of membranes to biofouling. Diverse materials, synthesis methods, and functionalization techniques will be needed to address different applications. Herein, we employed a novel ultrasonic-assisted technique to functionalize polyvinylidene fluoride microfiltration membranes by silver-based metal-organic frameworks (AgMOFs). Polydopamine (PDA) coating was also used to carry out this surface modification. In this study, AgMOFs were synthesized and in-situ grafted on the membrane surface simultaneously using ultrasonication for the first time. Unlike the conventional methods in which AgMOFs are prone to be washed away, the AgMOFs synthesized by ultrasonic-assisted method strongly bonded with the PDA-coated membrane. In addition, the MOF-PDA membrane fabricated by this method showed more uniform and size-controlled AgMOFs on the membrane surface than other conventional methods with large MOF clusters. The AgMOF-functionalized membrane displayed enhanced static antibacterial activity and dynamic biofouling resistance compared to those of the PDA-coated and pristine membranes while in contact with the model bacteria, Escherichia coli and Staphylococcus aureus. These results were evidenced by a larger inhibition zone area, a decline in viable cells observed in static antibacterial experiments, and more retained water flux in dynamic biofouling experiments. Altogether, our findings indicate that the in-situ synthesis of AgMOFs on membrane surfaces was successful by this facile and environmentally friendly method which can be considered in future studies with the purpose of surface modification for diverse applications.
Firms operating internationally need to ascertain effective relationship marketing (RM) strategies for their foreign operations. One set of RM strategies is based on understanding and using switching costs perceptions. Based on data from 1,630 customers across 16 countries, we examine the interplay between culture and switching costs perceptions using Triandis and Gelfand's four cultural personal value dimensions (CPVs), horizontal and vertical individualism and collectivism. These CPVs are assessed on external switching costs (ESC) and internal switching costs (ISC) perceptions along with additional important outcomes, including commitment and share of wallet. We find vertical individualism (VI), horizontal collectivism (HC), and vertical collectivism (VC) positively relate to ESC, and VI and VC positively relate to ISC. VI produced the strongest relationship with both switching costs. Our findings indicate the importance of including the horizontal/vertical dimension in studying cultural values. Implications for RM strategies internationally are offered.
Background Research software plays an important role in solving real-life problems, empowering scientific innovations, and handling emergency situations. Therefore, the correctness and trustworthiness of research software are of absolute importance. Software testing is an important activity for identifying problematic code and helping to produce high-quality software. However, testing of research software is difficult due to the complexity of the underlying science, relatively unknown results from scientific algorithms, and the culture of the research software community. Aims The goal of this paper is to better understand current testing practices, identify challenges, and provide recommendations on how to improve the testing process for research software development. Method We surveyed members of the research software developer community to collect information regarding their knowledge about and use of software testing in their projects. Results We analysed 120 responses and identified that even though research software developers report they have an average level of knowledge about software testing, they still find it difficult due to the numerous challenges involved. However, there are a number of ways, such as proper training, that can improve the testing process for research software. Conclusions Testing can be challenging for any type of software. This difficulty is especially present in the development of research software, where software engineering activities are typically given less attention. To produce trustworthy results from research software, there is a need for a culture change so that testing is valued and teams devote appropriate effort to writing and executing tests.
Seismic coherence is one of the seismic fault attributes that can be used to aid in seismic fault and stratigraphic interpretation. Traditionally seismic coherence is computed by measuring the similarity between waveforms of 2D or 3D seismic volumes. Recently computing seismic fault attribute is treated as an image segmentation problem and computed using different deep learning (DL) architectures. Currently, Researchers mainly concentrate on applying cutting-edge DL architectures in computing seismic fault attribute. There are few publications on exploring factors, which can be classified into data and method categories, that affect the performance of seismic image segmentation by using DL methods. To explore the factors in computing fault attribute, we compare the computed fault probability using DL architectures under different scenarios. The designed scenarios aim to dig the leading factor that affects the accuracy and resolution of seismic image segmentation. The proposed comparisons are applied to one marine seismic survey and one land seismic survey, respectively. The results demonstrate that properly preparing training data is far more important than choosing a cutting-edge DL architecture in computing seismic fault attribute. We also propose a practical workflow that can include real seismic data and corresponding labels in training data for a specific seismic survey.
Although there is cultural variability in how individuals make attributions for their own and others’ behaviors, cultural variation in youth’s attributions about peer victimization and their relation with internalizing problems has gone unexamined. To address this issue, adolescents from the U.S. (n = 292, 60% female, 79.5% White, Mage = 13.6, SD = 0.65) and Korea (n = 462, 50.2% female, Mage = 13.7, SD = 0.58) reported on their peer victimization, depressive symptoms, social anxiety, self-worth, and rated their attributions to vignettes about peer victimization. Multigroup confirmatory analyses found that Korean and American youth conceptualized characterological self-blame, behavioral self-blame, and externalization of blame similarly. However, Korean youth differentially endorsed each of the three types of attributions, while U.S. adolescents endorsed characterological self-blame and behavioral self-blame at similar levels. Attributions had unique relations with internalizing problems (depression, social anxiety, global self-worth) in each culture. In multigroup SEM analyses, characterological self-blame predicted all internalizing problems for U.S. adolescents, while behavioral self-blame was not uniquely related to internalizing problems. For Korean adolescents, behavioral self-blame significantly predicted all internalizing problems, whereas characterological self-blame predicted global self-worth only. The results suggest that attributions about victimization have different adjustment implications in Korea than in the U.S.
Research that illuminates causes of urban forest storm damage is valuable for planning and management. However, logistical and safety concerns often delay post-storm surveys in urban areas; thus, surveys may include observations with unverified sources of damage. While this uncertainty is often ignored, it can make up a high proportion of the number of damaged trees. The goal of this research was to improve understanding of techniques for modeling storm damage in urban forests. Using urban forest storm damage inventories collected in Florida, post-Hurricane Irma (2017), we tested how different imputation methods, modeling procedures, and damage frequency levels could impact overall model results. We utilized machine learning algorithms Random Forest (RF) and k-Nearest Neighbors (KNN), and generalized linear models (GLM). We found that GLM and RF models gave overall unbiased predictions of damage across all methods and rarity levels, while KNN consistently under-predicted damage. Damage frequency influenced some measures of performance but did not impact variable significance. Imputation methods all identified consistent variables of most significance within each model procedure; however, there was variation among variables ranked moderately important. While both GLM and RF models identified plot tree basal area as highly significant damage predictors, they otherwise disagreed on individual variable importance. These findings suggest that while explanatory models for urban forest storm damage can be achieved by examining linear relationships, more complex relationships such as the ones identified by RF models can have equal explanatory power with different subsets of predictor variables.
Firms often use new product preannouncements (NPPAs) to attract investors and inform them about innovative offerings in the pipeline. We observe that the appeal of an NPPA differs for retail and institutional investors. Utilizing prospect theory, we argue that the two types of investors face unequal levels of uncertainty and are dissimilarly loss averse due to varying levels of knowledge and access to resources. This results in varying attitudes towards investment horizon, risk-taking, and preference for information sources. We find investor proclivity toward an NPPA depends on several factors, including the short-term abnormal return, the valence of coverage in media and analyst reports, the firm's risk profile, and the exploration emphasis of the firm. Moreover, we show that higher levels of institutional ownership ultimately contribute to new product success. The results hold implications for strategies that managers can employ to increase investor ownership within the firm to fund innovation.
This paper reports on a qualitative case study of an often-overlooked language teacher: The graduate teaching assistant (GTA). The study relies on the theoretical premise that teachers’ professional learning is a process of identity construction. During this process, teachers experience tensions as they are introduced to professional authoritative discourses (ADs) and negotiate internally persuasive discourses (IPDs). In the qualitative case study of Karina, a GTA at a US University (State University, henceforth), we address the research question: How did Karina navigate her identity tensions as a GTA in the German program at State University? Our findings detail the effect of authoritative discourses in the program, and a GTA's agency in developing her own IPD.
The plate and shell heat exchanger (PSHE) was developed to overcome the traditional gasketed plate heat exchangers (PHE) operation limits. Its constructive characteristics allow higher-pressure and thermal applications, suitable for processes found in power plants and the oil and gas industry. However, studies on the PSHE thermo-hydraulic performance are still scarce. This study presents an experimental and theoretical analysis of the flow and heat transfer characteristics of a PSHE. A test rig operates with water and viscous oil to produce turbulent and laminar flow regimes, typical of the oil and gas industry. The heat transfer rate, pressure drop, and flow distribution are measured. The m²-model, developed to predict flow maldistribution on the PHE, is suitable for the plate side of the PSHE. An analytical model is used to correct the effects of maldistribution on the overall heat transfer coefficient and provide Nusselt number correlations. Experiments show that the flow maldistribution increases the heat exchanger pressure drop and deteriorates the heat transfer performance. The maximum and average channel flow rate ratio reaches 2.30 on the shell side and 1.75 on the plate side. Friction factor correlations are created based on the channel pressure drop data. The shell side has an inferior overall performance than the plate side, with a higher maldistribution and a lower Nusselt number. The PSHE effectiveness deterioration due to the maldistribution is 4% in the worst scenario within the experimental range. Results indicate that the PHE thermo-hydraulic performance is superior to the PSHE. Nevertheless, the structural advantages of the PSHE make it appropriate for applications involving high pressures and elevated temperatures.
To make the jump from laboratories to commercial production for perovskite solar cells, it is necessary to develop devices in an ambient environment using materials and methods that can be scalable. Here, blade coating followed by vacuum quenching is used to manufacture the FACs-based perovskite solar cells with the additive of MACl under an ambient environment (30%–57% RH), where FA is formamidinium and MA is methylammonium. The vacuum allows quick removal of solvent to initiate the nucleation process and create the intermediate phase. To control the nucleation and crystallization, the additive MACl is utilized to manipulate the intermediate phase. Besides perovskites, another key component is the hole transport material. Although nickel oxide exhibits good photostability and can be scalable for the inverted device architecture, the main drawback is low cell efficiency. This work solves it by tuning the cation ratio of Pb²⁺ to A⁺ and light soaking, achieving a champion efficiency of 19.5%. The encapsulated solar cells exhibit long-term photostability, maintaining 96% of their original efficiency and 91.5% of their maximum efficiency over 648 h under one sun at 45°C and 50%–60% relative humidity. This work demonstrates an economical and highly scalable process, promising for commercial-scale manufacturing.
For centuries, glass money beads (udoud) have played a critical role in cultural and economic exchanges in the Palauan archipelago (western Micronesia) since their first appearance ca. AD 600-950 from East Java and mainland Southeast Asia. Later, as part of their stone money (rai) quarrying activities, visiting Yapese islanders negotiated access to quarry sites and purchased provisions using glass beads, corvée labor, and other exchange valuables. Here, we present morphological and chemical composition analysis of 38 glass beads recovered from Chelechol ra Orrak, the only quarry site where udoud have been recovered. Analysis reveals that most of the beads were manufactured in Europe, with many originating in Bohemia (present-day Czech Republic) ca. AD 1830-1850. Many of these beads would have been regarded as cheldoech, a category of udoud that largely went out of circulation in the 1920s due to the ease of counterfeiting. Although this category of udoud could be easily counterfeited and beads from Yap lacked the requisite life histories associated with traditional udoud, Palauans accepted them as authentic. However, our research suggests that cheldoech may have depreciated in value well before the 1920s, with Palauans valuing and exchanging this category of udoud in new ways, including interment with burials.
Transportation agencies are responsible for balancing public safety and environmental impacts in their winter roadway maintenance operations. In managing the environmental impact of deicing procedures, a minimum effective dose should be used and less harmful deicing substances should be considered based on rigorous standardized tests. The subject research presents a modified laboratory test procedure and test apparatus for implementation in the evaluation and selection of deicing agents and definition of an appropriate and efficient application rate. The proposed test procedure is less cumbersome, produces more readily controlled experimental conditions, and is expected to provide improved reproducibility compared to current test methods. This modified approach is then used to evaluate the efficacy of several liquid deicing agents which could be used as an alternative to conventional NaCl brine. The comparative testing found that alternative deicing agents performed as well or better than NaCl brine, sometimes even at lower application rates. In particular, the addition of biocomponents or glycerol byproducts was shown to improve performance of chloride deicing agents.
Despite research linking teachers’ occupational health to student outcomes, the processes through which these associations exist are unknown. In a sample of 516 teachers, four latent profiles of occupational health were identified, indicated by job stress, occupational burnout, and teaching self-efficacy: lowest occupational health (17%), low-to-mid occupational health/mid self-efficacy (38%), mid-to-high occupational health/mid-self-efficacy (30%), and highest (15%) occupational health. Proactive behavior management practices were observed less frequently for teachers in the lowest (vs. highest) occupational health profile. White female teachers were associated with profiles of low occupational health more than White male teachers, and male and female teachers of color.
The detection of an astrophysical flux of neutrinos in the TeV–PeV energy range by the IceCube Neutrino Observatory has opened new possibilities for the study of extreme cosmic accelerators. The apparent isotropy of the neutrino arrival directions favors an extragalactic origin for this flux, potentially created by a large population of distant sources. Recent evidence for the detection of neutrino emission from extragalactic sources includes the active galaxies TXS 0506+056 and NGC 1068. We here review the current status of the search for the sources of the high-energy neutrino flux, concentrating on its extragalactic contribution. We discuss the implications of these observations for multimessenger studies of cosmic sources and present an outlook for how additional observations by current and future instruments will help address fundamental questions in the emerging field of high-energy neutrino astronomy. Expected final online publication date for the Annual Review of Nuclear and Particle Science, Volume 72 is September 2022. Please see for revised estimates.
Recycling reclaimed asphalt pavement (RAP) has attracted extensive attention for its environmental sustainability. As a typical industrial solid waste, steel slag with magnetic phase can facilitate the induction healing efficiency of asphalt mixtures. However, few researches focused on the healing characteristics of recycled asphalt mixtures with steel slag. Hence, this issue deserves systematic investigation. In this study, the chemical composition and static magnetic properties of steel slag with different particle size were estimated. And the induction heating performance, healing efficiency, multiple healing characteristic and healing rate after aging of their recycled asphalt mixtures were determined. The results indicate that magnetic hysteresis loops of steel slags reveal the typical narrow S-type curves, representing their magnetically soft characteristic with low coercivity. The highest Fe content and superior static magnetic properties are discovered in ASSF with particle sizes of 9.5–16 mm, and its saturation magnetization and coercivity gain up to 2.13 emu/g and 148.09 Oe. The ascending particle size of steel slag incorporated in recycled asphalt mixtures accelerates its induced temperature increment, effective heating depth and healing efficiency in contrast to the RAP addition. R7 with all component steel slag possesses the highest fracture energy of 685 J/m2 and HRE of 51.6% after healing. Healing rate of recycled asphalt mixtures grows in the previous four cycles and then start to reduce during the fifth cycle. R40 demonstrates the maximum HRS of 57.9% after the fourth cycle with a 10.7% diminution than R0, which maintains a desirable level. Long term aging boosts the attenuation degree of the self-healing performance for RAM with the increase of RAP dosage. HRAS of R40 undergone aging declines by 21.3% and merely reaches 29.1% due to the faster aging rate and inferior diffusion velocity into the cracks of recycled asphalt in recycled asphalt mixtures.
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7,646 members
Yonghyun Kim
  • Department of Chemical and Biological Engineering
Peter Letcher
  • Department of Biological Sciences
Michael Mckain
  • Department of Biological Sciences
John Shacka
  • Department of Pathology
Hyeonjin Lee
  • College of Engineering
35487, Tuscaloosa, Alabama, United States
Head of institution
Stuart R. Bell
(205) 348-6010