Utah State University
  • Logan, Utah, United States
Recent publications
Mapping the spatial distribution of soil organic carbon (SOC) in lands covered by tropical forests is important to understand the relationship and dynamics of SOC in this type of ecosystem. In this study, the Random Forest (RF) algorithm was used to map SOC stocks of topsoil (0–15 cm) in forest lands of the Dominican Republic. The methodology was developed using geospatial datasets available in the Google Earth Engine (GEE) platform combined with a set of 268 soil samples. Twenty environmental covariates were analyzed, including climate, topography, and vegetation. The results indicate that Model A (combining all 20 covariates) was only marginally better than Model B (combining topographic and climatic covariates), and Model C (only combining multispectral remote sensing data derived from Landsat 8 OLI images). Model A and Model B yielded SOC mean values of 110.35 and 110.87 Mg C ha−1, respectively. Model A reported the lowest prediction error and uncertainty with an R2 of 0.83, an RMSE of 35.02 Mg C ha−1. There was a strong dependence of SOC stocks on multispectral remote sensing data. Therefore, multispectral remote sensing proved accurate to map SOC stocks in forest ecosystems in the region
Background Relative to temperate regions, little is known about bobcats ( Lynx rufus ) in the Sonoran Desert portion of their range, in part due to the difficulty of sampling an elusive carnivore in harsh desert environments. Here, we quantify habitat selection and evaluate diet of bobcats at Kofa National Wildlife Refuge, Arizona, USA, using multiple sampling techniques including GPS telemetry, camera traps, and DNA metabarcoding. Results Home ranges during the hot season were smaller than during the cool season. Camera trapping failed to yield a high enough detection rate to identify habitat occupancy trends but third-order resource selection from GPS-collar data showed a preference for higher elevations and rugged terrain at lower elevations. Diet composition consisted of a diverse range of available small prey items, including a higher frequency of avian prey than previously observed in bobcats. Conclusions Desert bobcats in our study maintained smaller home ranges and primarily consumed smaller prey than their more northern relatives. This study illustrates the benefit of employing multiple, complementary sampling methods to understand the ecology of elusive species.
Prior studies have shown contrasting findings that tourism positively and/or negatively affects community resilience. This study explores the spatially heterogeneous mixed effects of tourism industry specialization on community resilience and identifies a key moderator that affects their positive/negative associations in 3108 counties in the United States and 67 counties in Florida. Geographically weighted regression combined with a spatial moderation analysis was applied to consider spatial interactions between communities. The findings show that tourism industry specialization has spatially heterogeneous mixed effects on community resilience, and these effects are significantly affected by environmental pollution. Specifically, the results demonstrate differences in the relationships between tourism industry specialization, community resilience, and environmental pollution in tourism-dependent communities and communities in general. Environmental pollution negatively affects the associations between community resilience and (a) arts/entertainment/recreation sectors in the United States and (b) accommodation/food service sectors in Florida. Theoretical and practical implications of the findings are also discussed.
This study investigates the effects of annotation on abstract and concrete visual representations in science education. Two studies were conducted: Study 1 investigated the interaction between annotation and visual representations. The results of this study demonstrated that in science learning, annotation with abstract visual representations was superior to annotation with concrete visual representations. Study 2 tested the expertise reversal effect in a three-factor design where the interaction among annotation, visual representation, and prior knowledge was measured. The findings showed that high-prior-knowledge learners performed better in the annotation-abstract visual condition than in the annotation-concrete visual condition where low-prior-knowledge learners showed the opposite outcome—confirming that the expertise reversal effect is at play in how science learners utilize visual information. The study has clarified the roles of prior knowledge, visual representation, and instructional strategy on learner cognitive processing in science education. This knowledge should prove useful for educators as they engage in the design and development of computer-based science learning.
Pollinators play pivotal roles in maintaining agricultural and natural plant communities, yet some bee populations are declining. Loss of pollinator habitats as a result of agricultural intensification and urbanization have reduced bee abundance and diversity. Additionally, climate change has affected bee distributions and led to disruption of plant-pollinator synchrony, impacting ecosystem processes. However, how these factors concurrently influence bee assemblages is poorly understood. Therefore, we evaluated bumble bee (Bombus) assemblages in relation to the proportion of agricultural, semi-natural, and urban land cover and interannual variation in temperature, precipitation, and relative humidity in Utah agroecosystems using Bombus captured as bycatch in pest monitoring traps from 2014 to 2018. Bombus assemblage composition was highest in agricultural sites with increased agricultural land cover in the surrounding area, low temperatures, and high relative humidity during the growing season; and lowest in sites with increased urban land cover, high temperatures, and low relative humidity. Functional dispersion did not differ among these groups indicating a range of tongue lengths, body sizes, hair lengths, and hair types were present within all agricultural sites. Further, high beta-diversity, as indicated by unique Bombus assemblages among sites, suggests that all agricultural sites in this study have potential conservation value for maintaining Bombus communities. Therefore, it is important that diverse habitats for pollinators are maintained through targeted management techniques. Additionally, our collection of Bombus from mid-May to mid-September identified phenological overlap within Bombus assemblages, which helps ensure pollination services are provided even if a particular species is lost due to environmental disturbances. However, while there is overlap in functional traits and phenology, considerations should be given due to widespread pollinator declines. Overall, evaluating landscape and climate variables together may yield more realistic results and better inform effective management and land-use planning strategies to prevent ecological homogenization and to foster future resiliency of Bombus populations.
Communities of Populus tremuloides are widespread in the north and central-west part of North America. A well-known aspen site is the Pando aspen clone, which is situated adjacent to Fish Lake, Utah. This stand of genetically identical trees is putatively the most massive organism on earth. Our pedoanthracological study is focused on the reconstruction of forest history in the Pando aspen stand. Results document presence and abundance of charcoal species during a period of nearly 9,000 years. While we make no attempt to explicitly identify the Pando genotype throughout this period, we can determine trends in dominant tree species which allows for the possibility of a single long-lived aspen specimen. The dominance of Populus charcoals was recorded in all soil profiles within the current Pando stand area. The radiocarbon data documented an increase of fire events over the last 2,000 years, which were probably related to human activities. Results of our study document the first multi-millennial pattern of aspen cover at a single locale. We relate this long-term pattern to restoration practices in contemporary stable aspen communities, since these practices are compatible with endemic disturbance processes. We believe that patterns and processes gleaned from this work will be instructive for forest management broadly, as well as preservation of aspen communities across in North American and globally.
Water planners must provide end-users with reliable and high-quality access to fresh water while complying with financial, institutional, and water availability constraints. In the pursuit of these goals, an over-investment in design can result in stranded assets of significant value and often unwanted environmental implications. Under-investment can lead to supply restrictions affecting human health, the economy, and the environment. The present study uses the Dominance-based Rough Set Approach (DRSA) to develop a balancing strategy concerning complexities encountered in water resource planning for irrigation systems. The methodology relies on the Dominance-based Learning from Examples Module (DOMLEM) algorithm, which extracts minimal set of rules regarding relevant combinations between flexibility allocation and design-cost criteria. The algorithm delineates outcomes in the form of “if., then.” rules that translate decision possibilities facing water planners into: “if (the design is more flexible by this amount), then (we expect this range of cost increment”). Then, a confusion matrix is computed for each irrigation system in order to exclude the rules generating incorrect and ambiguous classification results. The outcome reveals that cost is more subject to elasticity at the hydrant (eh) increment than the network’s coefficient (r). Furthermore, the analysis reveals that the parameter P(q) has only a minor impact on the cost and, as a result, the final decision. Any elasticity (eh) less than 3 assigned to any given coefficient (r) becomes a low-cost increment. For any given value of (eh), the cost increases as the coefficient (r) decrease. Elasticity from 4 to 5 with a network's coefficient (r) equal to or greater than 18/24 becomes a medium-cost increment. Elasticity (eh) from 5 to 6 associated with an (r) equal or less than 16/24 becomes a very high-cost increment. Finally, rather than identifying one solution that seems better than others, this approach provides an interactive schematic that helps identify the appropriate range of flexibility justified by the expense criterion, which allows for debate and supports decision-making.
Substance use disorders (SUDs) are a chronic disease that impacts the individual with a SUD as well as an entire family system. While family members of those with SUDs are one of the most important support networks in the recovery process, impacted family members have been found to experience more adverse health outcomes and altered functioning of the prefrontal cortex (PFC). These impacts negatively influence not only family members’ personal health but also the health of the family unit, which limits the family’s capability of providing its most effective support. Bowen’s conceptualization of differentiation of self can help explain the perspective of SUDs as a “family disease” and associated impacts on family members. Using functional near-infrared spectroscopy with a sample of 26 SUD-impacted family members, the present study examined associations between PFC activation in response to images of a loved-one seeking abstinence from a SUD and various components of differentiation of self (i.e., emotional cutoff, emotional reactivity, fusion with others, and I-position). Activation of the left dorsomedial PFC in response to SUD loved-one images associated negatively with emotional reactivity and positively with fusion with others. These findings did not replicate in a control group and have important implications for research and clinical practice.
Sustainable management of protected areas requires attention to the structures, processes, institutions, and funding mechanisms that support them. When protected areas transcend multiple jurisdictions and landownerships, effective governance requires engagement of multiple institutions. In the United States, 11 National Scenic Trails (NSTs) extend across multiple states, landownerships, and jurisdictions, with regional and national partnerships enhancing management capacity. Trail governance requires a systems approach – coordinating among governmental and nongovernmental partners at multiple scales. We conducted 17 interviews with NST administrators and partners and gathered secondary data about trail characteristics and governance to explore existing trail capacities. Here, we explore NSTs along four dimensions of governance that shape trail management: structural and foundational elements, landownership regimes, trail funding, and partnerships. Understanding these dimensions can inform managers of NSTs and other protected areas crossing multiple jurisdictions, helping them recognize strengths and gaps in institutional form and capacity, and strategies for effective governance.
Using a sample of 3678 firm-year observations with discontinued operations from 1992 to 2019, and a matched sample of 3678 observations without discontinued operations, we find a significant positive relationship between CEO power and discontinued operations, measured as the likelihood and magnitude of discontinued operations. Our results suggest that more powerful CEOs are more likely to discontinue business operations and report a larger magnitude of discontinued operations than less powerful CEOs.
Probabilistic seismic demand analysis (PSDA) is the most time-and effort-intensive step in risk-based assessment of the built environment. A typical PSDA requires subjecting the structure to a large number of ground motions and performing nonlinear dynamic analysis, where the analysis dimension and effort substantially increase at large-scale assessments such as community-level evaluations. This study presents a deep learning framework to estimate seismic demand models from nonlinear static (i.e., pushover) analysis, which is computationally inexpensive. The proposed architecture leverages an encoder-decoder model with customized training schedules and a loss function capable of determining demand model parameters and error. Furthermore, the framework facilitates the seamless incorporation of structural modeling uncertainties in PSDA. The proposed framework is then applied to a building inventory consisting of 720 concrete frames to examine its generalizability and accuracy. The results show that the deep learning architecture can estimate demand models by an R 2 of 84% using a test-to-train ratio of unity. In addition, the average prediction error is less than 3% and 6% for demand model slope and intercept parameters , respectively, translating into an accurate estimation of fragility functions with a median error of 5.7%, 6.9%, and 6.8% for immediate occupancy, life safety, and collapse prevention damage states. Lastly, the framework can efficiently propagate structural uncertainties into seismic demand models, capturing the implicit relationship of the frames' nonlinear characteristics and resultant fragility functions.
Understanding carbon dioxide (CO2) reservoir to surface migration is crucial to successful carbon capture and sequestration approaches; especially fault/reservoir interactions under injection pressure. Through seismic imaging, we explore regolith and shallow stratigraphy across the Little Grand Wash fault. The presence of natural CO2 seeps, travertine and tufa deposits confirm modern and ancient fault-controlled CO2 leakage. We consider this an analogue for a long-failed sequestration site. We estimate bulk porosity and fracture density for host rock, regolith, and fault zone from petrophysical relationships. When combined with existing geochemical and geological data, we characterize a 60 m wide damage zone that represents the primary surface delivery channel for CO2 originating from reservoir depths. Within this damage zone, low seismic velocities suggest sediments have formed through host rock chemical dissolution or mechanical weathering. In contrast, velocities within the adjacent host rock are consistent with low fracture density clastic rocks. We measure anomalously high seismic velocities within the fault zone along one profile that best represents a sealed (cemented/plugged) low permeability, relic flow channel. This suggests that shallow fault zone permeability varies along strike. While regional stress changes may account for decadal- to millennial-scale changes in CO2 pathways, we speculate that the total fluid pressure has locally reduced the fault's minimum horizontal effective stress; thereby producing both low- and high-permeability fault segments that either block or promote fluid migration. Studying CO2 migration in this system can inform potential risks to future sequestration projects and guide monitoring efforts.
Oxytocin is an endogenous neuropeptide hormone that influences social behaviour and bonding in mammals. Variations in oxytocin receptor (OXTR) expression may play a role in the social deficits seen in autism spectrum disorder. Previous studies from our laboratory found a dense population of OXTR in the human substantia nigra (SN), a basal ganglia structure in the midbrain that is important in both movement and reward pathways. Here, we explore whether differences in OXTR can be identified in the dopaminergic SN pars compacta of individuals with autism. Postmortem human brain tissue specimens were processed for OXTR autoradiography from four groups: males with autism, females with autism, typically developing (TD) males and TD females. We found that females with autism had significantly lower levels of OXTR than the other groups. To examine potential gene expression differences, we performed in situ hybridization in adjacent slides to visualize and quantify OXTR mRNA as well as mRNA for tyrosine hydroxylase. We found no differences in mRNA levels for either gene across the four groups. These results suggest that a dysregulation in local OXTR protein translation or increased OXTR internalization/recycling may contribute to the differences in social symptoms seen in females with autism. This article is part of the theme issue ‘Interplays between oxytocin and other neuromodulators in shaping complex social behaviours’.
The purpose of this cross-sectional study was to determine the differences in narrative macrostructure abilities of children in different age groups using a progress monitoring tool based in discourse theory. A majority of existing research regarding narrative developmental patterns has been based in schema theory. The Monitoring Indicators of Scholarly Language (MISL) rubric is based in discourse theory and was designed to characterize aspects of narrative proficiency in school-age children. The data for this project consisted of 687 narratives elicited using the Aliens subtest from The Test of Narrative Language—Second Edition (TNL-2). There were 1,597 participants who ranged in age from 4; 0 to 15; 0 (year; month). An ordinary least squares regression where age predicted total macrostructure score, followed by a series of post hoc ordinal logistic regressions (OLR) where age predicted each individual MISL rubric element was used. Results of both the simple regression on total macrostructure score and the series of ordinal regression analyses for each macrostructure element indicated that age was a significant predictor of the scores children received. Collectively, these results suggest that the MISL is a developmentally valid measure of narrative production abilities. Developmental milestones based on discourse theory are reported to be substantially later than has been reported for schema theory. The differences are highlighted and the implications for progress monitoring for narrative development are discussed.
Infections by maternally inherited bacterial endosymbionts, especially Wolbachia , are common in insects and other invertebrates but infection dynamics across species ranges are largely under studied. Specifically, we lack a broad understanding of the origin of Wolbachia infections in novel hosts and the factors governing their spread. We used Genotype-by-Sequencing (GBS) data from previous population genomics studies for range-wide surveys of Wolbachia presence and genetic diversity in over 2,700 North American butterflies of the genus Lycaeides . As few as one sequence read identified by assembly to a Wolbachia pan-reference genome provided high accuracy in detecting infections as determined by confirmatory PCR tests. Using a conservative threshold of five reads, we detected Wolbachia in all but two of the 107 sampling localities spanning the continent, and with most localities having high infection frequencies (mean = 91\% infection rate). Three major lineages of Wolbachia were identified as separate strains that appear to represent three separate invasions of Lycaeides butterflies. Overall, we found extensive evidence for acquisition of Wolbachia through interspecific transfer between host lineages. Strain wLyc C was confined to a single butterfly taxon, hybrid lineages derived from it, and closely adjacent populations in other taxa. While the other two strains were detected throughout the rest of the continent, strain wLyc B almost always co-occurred with wLyc A. Our demographic modeling suggests wLyc B is a recent invasion. These results demonstrate the utility of using resequencing data from hosts to quantify Wolbachia genetic variation and provide evidence of multiple colonizations of novel hosts through hybridization between butterfly lineages and complex dynamics between Wolbachia strains.
Relationships and interactions among predators are multifaceted and intricate, and they affect the fitness and survival of individuals. We followed and watched nine habituated honey badgers, Mellivora capensis, during >5,800 h over a 42-month period to investigate their direct interactions with sympatric carnivorous mammals and birds in the southern Kalahari, South Africa. We recorded foraging associations between honey badgers and seven other species (two mammals, five birds), most commonly facultative commensalist or “producer–scrounger” interactions between honey badgers and pale chanting-goshawks, Melierax canorus, and black-backed jackals, Canis (Lupullela) mesomelas. The goshawks and jackals benefited from increased hunting opportunities and intake rate. In addition, goshawks showed increased strike success and an expanded prey base when hunting with honey badgers compared to hunting alone in a similar habitat in the Little Karoo. Overall honey badgers did not show any significant differences in digging success, intake rate or predator vigilance when foraging in association compared to foraging alone. The only exception relates to the jackal–badger association that resulted in a significant decrease in the amount of prey caught above ground by honey badgers – 5% of their prey overall. This form of kleptoparasitism by jackals may have costs for honey badgers in the cold-dry season, when prey availability is low and the foraging association is most common. Based on our field observations and previously published dietary analyses, we recorded or inferred antagonistic interactions between honey badgers and 12 other carnivore species. The outcomes of interspecific aggression (i.e. interference competition) could be predicted from relative body size, and were largely asymmetrical. Intraguild predation was common and honey badgers preyed or attempted to prey on all mammalian carnivores smaller than themselves, as well as the young of medium-sized carnivores. Lions, Panthera leo, leopards, Panthera pardus, and probably spotted hyenas, Crocuta crocuta, preyed on honey badger adults and cubs, and cubs were killed by black-backed jackals. The web of interactions observed to date in the taxocenosis of Kalahari carnivores is complex, and we encourage further investigations to help better understand how interactions between carnivores shape the whole community structure, both in pristine and altered ecosystems.
Objectives The study aimed to describe daily sleep characteristics for dementia care dyads in the context of adult day services (ADS) use and examine the associations with sleep quality and daytime functioning (fatigue, affect, and behavior problems). Methods Caregivers (CG; N = 173) reported daily bedtime, wake time, and sleep quality for themselves and the persons living with dementia (PLWD) across 8 consecutive days (N = 1359), where PLWD attended ADS at least 2 days of the week. On each day, caregivers also reported their own fatigue and affect and PLWD’s daytime behavior problems and nighttime sleep problems. Considering the context of ADS use, we compared mean differences in bedtime, wake time, and total time in bed on nights before versus after ADS use. We estimated multilevel models to examine daily sleep-well-being associations. Results On nights before an upcoming ADS day, care dyads went to bed and woke up earlier, and spent less time in bed. Further, PLWD had better sleep quality the night before an upcoming ADS day. Using ADS during the day buffered the negative impact of PLWD’s sleep problems in the previous night, reducing daytime negative affect for caregivers. For caregivers, using ADS yesterday attenuated the association between shorter than typical time in bed and daytime fatigue; it also attenuated the association between PLWD’s nighttime sleep problems and lowered daytime positive affect. Conclusions Regular ADS use may promote earlier sleep timing and protect against the adverse impact of sleep disturbances on daytime functioning for dementia care dyads.
Purpose The purpose of this project was to examine the effect of the COVID-19 pandemic on speech-language pathologist (SLP) service provision for emergent bilinguals who use augmentative and alternative communication (AAC). One prominent issue in AAC service delivery is the efficacy and feasibility of providing AAC services via telepractice. The COVID-19 pandemic intensified this issue as most providers, clients, and families adjusted to remote service delivery models. While emerging evidence supports telepractice in AAC, little is known about the potential benefits and challenges of telepractice for emergent bilinguals who use AAC and their families. Method Data were collected via a nationwide survey. Licensed SLPs ( N = 160) completed an online questionnaire with Likert-type, multiple-choice, and open-ended questions, analyzed using mixed methods. Results Findings illustrated a shift in service delivery from in-person to telepractice and hybrid (both telepractice and in-person) models. Overall, child intervention outcomes declined for emergent bilinguals who used AAC during the COVID-19 pandemic, regardless of service delivery format. However, collaboration increased for many providers and families. Qualitative analyses highlighted barriers to AAC service provision for emergent bilinguals who use AAC that were exacerbated by the COVID-19 pandemic, as well as factors that facilitated collaboration and family engagement. Conclusion These findings suggest that, despite challenges, telepractice or hybrid services may be a promising approach to provide more culturally responsive, family-centered care for emergent bilinguals who use AAC. Supplemental Material https://doi.org/10.23641/asha.20405673
We review ethnographic methods that allow researchers to assess distress in a culturally sensitive manner. We begin with an overview of standardized biomedical and psychological approaches to assessing distress cross-culturally. We then focus on literature describing the development of reliable and valid culturally sensitive assessment tools that can serve as complements or alternatives to biomedical categories and diagnostic frameworks. The methods we describe are useful in identifying forms of suffering—expressed in culturally salient idioms of distress—that might be misidentified by biomedical classifications. We highlight the utility of a cognitive anthropological theoretical approach for developing measures that attend to local cultural categories of knowledge and experience. Attending to cultural insider perspectives is necessary because expressions of distress, thresholds of tolerance for distress, expectations about stress inherent in life, conceptions of the good life, symptom expression, and modes of help-seeking vary across cultures.
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5,015 members
Catalin V Buhusi
  • PhD Program in Neuroscience and PhD Program in Psychology (“Brain and Cognition” specialization)
Claudia Radel
  • Department of Environment and Society
David Stevens
  • Utah Water Research Laboratory
Charles P Hawkins
  • Department of Watershed Sciences
Rong Li
  • Dept. Animal Science
84322, Logan, Utah, United States