University of Oklahoma
  • Norman, OK, United States
Recent publications
Introduction Triathlon can be considered one of the most successful endurance sports worldwide due to the wide dissemination of information, expansion of the offer of competitions, and greater popularity. Objective To analyze Brazilian triathletes’ sociodemographic, socioeconomic, and motivational profiles. Methods 411 triathletes participated in the study, 127 women [37.87 ± 9.34 years] and 284 men [36.02 ± 9.23 years]. Three questionnaires were sent electronically to assess sociodemographic, socioeconomic, and motivational data. In addition, descriptive analyses and statistical tests were performed to compare motivation between age, sex, and technical level groups. Results It was found that there is a prevalence of male triathletes, amateurs, aged between 30-40 years, employed and economically favored. Amateur athletes have running as a base sport for Triathlon, and professionals start their sports career through swimming. Among the most practiced distances are the sprint Triathlon and half Ironman. Regarding motivation, women differ in the dimensions of group activity (p=0.020), emotion (p=0.002), and technical competence (p=0.007). Professional triathletes had higher scores in the dimensions of social recognition (p=0.001) and competition (p=0.001) and lower scores in the physical fitness dimension (p=0.005). Triathletes aged between 35 and 49 years had lower averages in the social recognition dimension (p=0.007), (p=0.012) and (p=0.004) and competition (p=0.028), (p=0.008) and (p=0.044) when compared to athletes aged 20 to 29 years. Conclusion the profile of Brazilian triathletes is diverse, and differences in sex, age, and technical level impacted the motivation of the evaluated triathletes. Level of Evidence III; Diagnostic studies - Investigation of a diagnosis test; Study of non-consecutive patients, with no uniformly applied “gold standard”. Keywords: Sports; Athletes; Motivation; Psychology, Sports
Wetlands are rich in biodiversity, provide habitats for many wildlife species, and play a vital role in the transmission of bird-borne infectious diseases (e.g., highly pathogenic avian influenza). However, wetlands worldwide have been degraded or even disappeared due to natural and anthropogenic activities over the past two centuries. At present, major data products of wetlands have large uncertainties, low to moderate accuracies, and lack regular updates. Therefore, accurate and updated wetlands maps are needed for the sustainable management and conservation of wetlands. Here, we consider the remote sensing capability and define wetland types in terms of plant growth form (tree, shrub, grass), life cycle (perennial, annual), leaf seasonality (evergreen, deciduous), and canopy type (open, closed). We identify unique and stable features of individual wetland types and develop knowledge-based algorithms to map them in Northeast China at 10 m spatial resolution by using microwave (PALSAR-2, Sentinel-1), optical (Landsat (ETM+/OLI), Sentinel-2), and thermal (MODIS land surface temperature, LST) imagery in 2020. The resultant wetland map has a high overall accuracy of >95%. There were a total 154,254 km 2 of wetlands in Northeast China in 2020, which included 27,219 km 2 of seasonal open-canopy marsh, 69,158 km 2 of yearlong closed-canopy marsh, and 57,878 km 2 of deciduous forest swamp. Our results demonstrate the potential of knowledge-based algorithms and integrated multi-source image data for wetlands mapping and monitoring, which could provide improved data for the planning of wetland conservation and restoration.
  • Kristen M. Rayfield
    Kristen M. Rayfield
  • Alexis M. Mychajliw
    Alexis M. Mychajliw
  • Robin R. Singleton
    Robin R. Singleton
  • [...]
  • Courtney A. Hofman
    Courtney A. Hofman
The accelerating pace of emerging zoonotic diseases in the twenty-first century has motivated cross-disciplinary collaboration on One Health approaches, combining microbiology, veterinary and environmental sciences, and epidemiology for outbreak prevention and mitigation. Such outbreaks are often caused by spillovers attributed to human activities that encroach on wildlife habitats and ecosystems, such as land use change, industrialized food production, urbanization and animal trade. While the origin of anthropogenic effects on animal ecology and biogeography can be traced to the Late Pleistocene, the archaeological record—a long-term archive of human–animal–environmental interactions—has largely been untapped in these One Health approaches, thus limiting our understanding of these dynamics over time. In this review, we examine how humans, as niche constructors, have facilitated new host species and ‘disease-scapes’ from the Late Pleistocene to the Anthropocene, by viewing zooarchaeological, bioarchaeological and palaeoecological data with a One Health perspective. We also highlight how new biomolecular tools and advances in the ‘-omics’ can be holistically coupled with archaeological and palaeoecological reconstructions in the service of studying zoonotic disease emergence and re-emergence.
Urban vegetation experiences multiple natural and human impacts during urbanization, including land conversion, local environmental factors, and human management, which may bring positive or negative impacts on vegetation gross primary productivity (GPP) at multi scales. In this study, we analyzed the spatial-temporal changes of GPP and three urbanization factors: land urbanization (Impervious surface coverage, ISC), population urbanization (Population), and economic urbanization (GDP) at city-district-grid scales in Beijing during 2000-2018. Overall, both GPP and three urbanization factors showed an increased trend. The relationships between GPP and urbanization factors exhibit diverse characteristics at multiple scales: unlike the linear relationship observed at city scale, the relationships at district and grid scales all demonstrated nonlinear relationship, even U shape between GPP and population / GDP. Furthermore, the positive impact of urbanization on GPP increased and offset the negative impact of land conversion from 9.9% in 2000 to 35% in 2018, indicating that urban management and climate during urbanization effectively promote vegetation photosynthesis and neutralize the negative impact of urban area expansion. Our findings highlight the increased growth offset by urbanization on vegetation and the importance of analysis at a finer scale. Understanding these urbanization types' impact on vegetation is pivotal in formulating comprehensive strategies that foster sustainable urban development and preserve ecological balance.
This study reports the results of an experiment ( N = 502) investigating how speakers are socially categorized based on accent (Standard American English [SAE] or Nigerian) and race (White or Black) separately and concurrently, as well as the intergroup outcomes of such categorizations as mediated by language attitudes (status, solidary, and dynamism). Findings revealed that SAE-accented speakers were evaluated more favorably than Nigerian-accented speakers on status. Status also mediated the relationship between accent and (a) symbolic threat and (b) social distance. Additionally, Black males were rated higher on solidarity and dynamism than White males. Finally, status mediated the combined effect of the speaker’s race and accent on symbolic threat, intergroup anxiety, and social distance. Theoretical and practical implications are discussed.
The design and performance of an apparatus for heating and cooling samples during variable temperature infrared spectroscopy studies are described. The apparatus incorporates two thermoelectric device modules in a stacked configuration. The cascaded devices are powered in parallel and contained within a metal enclosure that maintains their alignment and applies clamping pressure between them to maximize thermal conductivity. By using this apparatus, sample temperatures can be increased or decreased at 2 °C s-1 rates and isothermal temperatures can be maintained precisely (±0.1 °C). The rapid heating and cooling capabilities of the apparatus facilitate programmed temperature step heating/cooling profiles with isothermal infrared spectrum measurements at pre-selected temperatures. Using linear heating and cooling temperature ramps, subtle temperature-dependent poly(styrene) infrared spectrum changes are elucidated and correlated with sample temperature. Results obtained by using a temperature step sample heating profile are compared with those obtained by using linear temperature ramp heating and cooling to characterize silica gel dehydration and re-hydration processes. By comparing infrared spectra acquired at different temperatures while heating and cooling the sample, silica gel spectrum changes associated with water desorption/adsorption and the thermal expansion/contraction of the Si-O-Si network are differentiated.
Optical three-dimensional (3D) molecular imaging is highly desirable for providing precise distribution of the target-of-interest in disease models. However, such 3D imaging is still far from wide applications in biomedical research; 3D brain optical molecular imaging, in particular, has rarely been reported. In this report, we designed chemiluminescence probes with high quantum yields, relatively long emission wavelengths, and high signal-to-noise ratios to fulfill the requirements for 3D brain imaging in vivo. With assistance from density-function theory (DFT) computation, we designed ADLumin-Xs by locking up the rotation of the double bond via fusing the furan ring to the phenyl ring. Our results showed that ADLumin-5 had a high quantum yield of chemiluminescence and could bind to amyloid beta (Aβ). Remarkably, ADLumin-5’s radiance intensity in brain areas could reach 4 × 10 ⁷ photon/s/cm ² /sr, which is probably 100-fold higher than most chemiluminescence probes for in vivo imaging. Because of its strong emission, we demonstrated that ADLumin-5 could be used for in vivo 3D brain imaging in transgenic mouse models of Alzheimer’s disease.
During 6–7 May 2017, a record‐breaking nocturnal rainfall event occurred in Guangzhou, China, and it was a typical warm‐sector heavy rainfall event under weak synoptic forcing. A prior observational study by the authors revealed that warm‐rain microphysical processes were dominant and responsible for the record‐breaking precipitation. In this study, the double‐moment Morrison, Thompson and NSSL microphysics schemes in WRF are evaluated against polarimetric radar observations in their ability of reproducing observed microphysical characteristics. The Thompson scheme shows the greatest fidelity to the observed raindrop size distribution (RSD) median value, corresponding to the most amount of precipitation forecast. While the Morrison and NSSL simulations overestimate (underestimate) the raindrop size (number concentration), exhibiting continental‐type convective precipitation. The three experiments slightly overestimate differential reflectivity ( Z DR ), but significantly underestimate specific differential phase ( K DP ) and liquid water content by about 30%–50%, implying the undervaluation of number of medium‐sized raindrops. Examinations of the occurrence frequencies of Z DR , K DP , mass‐weighted diameter, and logarithmic normalized intercept parameter for rain suggest that all three schemes fail to reproduce the full variability of observed RSD for the extreme rainfall. The vertical variations of RSD parameters and the Kumjian‐Ryzhkov parameter space suggest that the collision–coalescence is the dominant warm‐rain microphysical process but the simulated process is too weak. This may be attributed to the misrepresented RSD near the melting layer, where the raindrops with lower number concentration and larger sizes cannot grow through the collision–coalescence process as actively.
High-precision U-Pb zircon ages on SE Newfoundland tuffs now bracket the Avalonian Lower–Middle Cambrian boundary. Upper Lower Cambrian Brigus Formation tuffs yield depositional ages of 507.91 ± 0.07 Ma ( Callavia broeggeri Zone) and 507.67 ± 0.08 Ma and 507.21 ± 0.13 Ma ( Morocconus-Condylopyge eli Assemblage interval). Lower Middle Cambrian Chamberlain’s Brook Formation tuffs have depositional ages of 506.34 ± 0.21 Ma ( Kiskinella cristata Zone) and 506.25 ± 0.07 Ma ( Eccaparadoxides bennetti Zone). The composite unconformity separating the Brigus and Chamberlain’s Brook formations is constrained between these ages. An Avalonian Lower–Middle Cambrian boundary between 507.2 ± 0.1 and 506.3 ± 0.2 Ma is consistent with maximum depositional age constraints from southwest Laurentia, which indicate an age for the base of the Miaolingian Series, as locally interpreted, of ≤ 506.6 ± 0.3 Ma. The Miaolingian Series’ base is interpreted as correlative within ≤ 0.3 ± 0.3 Ma between Cambrian palaeocontinents, although its exact synchrony is questionable due to taxonomic problems with a possible Oryctocephalus indicus -plexus, invariable dysoxic lithofacies control of O. indicus and diachronous occurrence of O. indicus in temporally distinct δ ¹³ C chemozones in South China and SW Laurentia. The lowest occurrence of O. indicus assemblages is linked to onlap (epeirogenic or eustatic) of dysoxic facies. A united Avalonia is shown by late Early Cambrian volcanics in SW New Brunswick; Cape Breton Island; SE Newfoundland; and the Wrekin area, England. The new U-Pb ages revise Avalonian geological evolution as they show rapid epeirogenic changes through depositional sequences 4a–6.
This study reviews the potential applications of the metaverse to various areas of human resource development (HRD) and reflects on the applications’ significance for employee and organizational development. Adopting a narrative review approach to this study, we selected and reviewed 34 cases. From our review, we found several findings that contributes to the HRD field in several ways. First, it draws the attention of HRD researchers and practitioners to a critical emerging trend that has been overlooked in the field. Second, it offers an analytical view of the metaverse in comparison to other training or learning technologies, assessing its effectiveness in employee development. Third, this study enhances the perspectives of HRD researchers and practitioners regarding this new technology by providing practical and theoretical insights into how metaverse-based interventions can reshape organizational culture and improve employee performance in the workplace. Lastly, it addresses compelling theoretical and practical questions related to HRD issues arising from the metaverse.
Reliability and resiliency assessment of an electrical distribution network (DN) for extreme disasters are essential for system optimization and future planning. Conventional reliability indices may not be effective in characterizing dynamic disturbance events in DNs. A unique opportunity to empirically explore these issues arose when a week of unseasonably cold weather moved through the State of Oklahoma. On October 26, 2020, a rare ice storm resulted in one of the most widespread power disruptions ever experienced in the state's history. This article documents the outcomes of an investigation conducted in collaboration with a utility provider who operates and maintains one of the affected DNs. Based on supplied network data, this article explores the quantification of operational resilience for a more insightful characterization of outage events. The results demonstrate important failure mechanisms and potential opportunities to improve resiliency.
In this article, a generalized theory of bandpass filtering attenuators (filtenuators) is proposed. A filtenuator is a device that combines the frequency-selective characteristics of a filter and the loss-programmable characteristics of an attenuator into a single component. The loss-programmable aspect of the filtenuator is based on the tuning of a $\pi$ -network of resistances, which are implemented using p-i-n diodes to control the individual resistance values electronically. A loss-programmable, third-order Chebyshev bandpass filtenuator is designed, fabricated, and measured to verify the generalized theory. The filtenuator is designed to operate at 1 GHz and has a tunable attenuation range of 2–10 dB. This proposed filtenuator demonstrates the feasibility of a tunable, low-cost, size, weight, and power (C-SWaP) solution to increase radio frequency (RF) system dynamic range and a design process that allows for future development of filtenuators.
In the United States, congressional redistricting follows a decennial Census. Gerrymandering can result from selection of district lines regardless of political parties. Understanding the relationships between the multiple dimensions in electoral data is a core goal of gerrymandering analysis. In this paper, we analyze patterns of gerrymandering in election data using a hybrid tree visualization technique that supports both overview and drill-down into a hierarchy of multidimensional relationships in that data. Visualization of hierarchical data is of major interest in information visualization. The technique utilizes a left-to-right node-link diagram to show overall hierarchical structure. Nodes in the diagram depict the levels in the dimensional hierarchy. Each node is rendered as an embedded view that shows its particular dimensional combination. Edges directly connect the contents of the embedded views to provide visual bridges that aid navigation and understanding of dimensional relationships. We demonstrate the utility of this hybrid technique is demonstrated through two use cases. This work aims to both ground and inspire the design of future visualizations for exploring gerrymandering.
Background In the United States there are roughly three million births a year, ranging from cesarean to natural births. A major aspect of the birthing process is related to the healing environment, and how that helps or harms healing for the mother and child. Using the theoretical framework, Theory of Supportive Care Settings (TSCS) this study aimed to explore what is necessary to have a safe and sacred healing environment for mothers. Method This study utilized an updated Qualitative Interpretive Meta-synthesis (QIMS) design called QIMS-DTT (deductive theory testing) to answer the research question, What are mother’s experiences of environmental factors contributing to a supportive birthing environment within healthcare settings? Results . Key terms were run through multiple databases, which resulted in 5,688 articles. After title and abstract screening, 43 were left for full-text, 17 were excluded leaving 26 to be included in the final QIMS. Four main themes emerged from analysis 1. Having control and agency within the birthing space, 2. Creating connections with support systems, 3. Being vulnerable, being flexible, and 4. Feeling safe within the birthing space. Conclusions Providing a warm and welcoming birth space is crucial for people who give birth to have positive experiences. Providing spaces where the person can feel safe and supported allows them to find empowerment in the situation where they have limited control.
Targeted amplicon sequencing is widely used in microbial ecology studies. However, sequencing artifacts and amplification biases are of great concern. To identify sources of these artifacts, a systematic analysis was performed using mock communities comprised of 16S rRNA genes from 33 bacterial strains. Our results indicated that while sequencing errors were generally isolated to low-abundance operational taxonomic units, chimeric sequences were a major source of artifacts. Singleton and doubleton sequences were primarily chimeras. Formation of chimeric sequences was significantly correlated with the GC content of the targeted sequences. Low-GC-content mock community members exhibited lower rates of chimeric sequence formation. GC content also had a large impact on sequence recovery. The quantitative capacity was notably limited, with substantial recovery variations and weak correlation between anticipated and observed strain abundances. The mock community strains with higher GC content had higher recovery rates than strains with lower GC content. Amplification bias was also observed due to the differences in primer affinity. A two-step PCR strategy reduced the number of chimeric sequences by half. In addition, comparative analyses based on the mock communities showed that several widely used sequence processing pipelines/methods, including DADA2, Deblur, UCLUST, UNOISE, and UPARSE, had different advantages and disadvantages in artifact removal and rare species detection. These results are important for improving sequencing quality and reliability and developing new algorithms to process targeted amplicon sequences. IMPORTANCE Amplicon sequencing of targeted genes is the predominant approach to estimate the membership and structure of microbial communities. However, accurate reconstruction of community composition is difficult due to sequencing errors, and other methodological biases and effective approaches to overcome these challenges are essential. Using a mock community of 33 phylogenetically diverse strains, this study evaluated the effect of GC content on sequencing results and tested different approaches to improve overall sequencing accuracy while characterizing the pros and cons of popular amplicon sequence data processing approaches. The sequencing results from this study can serve as a benchmarking data set for future algorithmic improvements. Furthermore, the new insights on sequencing error, chimera formation, and GC bias from this study will help enhance the quality of amplicon sequencing studies and support the development of new data analysis approaches.
Shale is known to exhibit significant creep across spatiotemporal scales. In this work, we performed indentation and triaxial creep tests on organic-rich Woodford shale and showed that the measured creep responses at the nanometer and millimeter scales are statistically correlated in the sense that the indentation creep tests can be used to predict the triaxial creep response. The link between the two extreme scales is facilitated by an elasto-viscoplastic constitutive model based on critical state theory. Even though this constitutive model contains several material parameters, only the elastic modulus and viscosity played a major role in statistically correlating the creep responses at the two scales. Given that shale is commonly represented as a transversely isotropic material, we conducted indentation and triaxial creep tests in both bed-normal (BN) and bed-parallel (BP) directions on the rock samples. For the shale that was tested, the creep responses at the nanometer and millimeter scales were statistically correlated in the BN direction where the rock is weaker. However, the creep deformations at the two scales in the BP direction, where the rock is stronger, were significantly smaller than in the BN direction, and so, they were not as strongly correlated. Nevertheless, the results of this study suggest that shale exhibits strongly anisotropic creep properties.
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Samuel Cheng
  • School of Electrical and Computer Engineering
Caryn C. Vaughn
  • Oklahoma Biological Survey
Shailendra Dwivedi
  • Department of Obstetrics and Gynecology
Norman, OK, United States