University of North Dakota
  • Grand Forks, North Dakota, United States
Recent publications
This study was conducted to evaluate the association between psychological impacts of delay on commuters and three indictors of the rail transport real-time information. The case study experienced sporadic long delay and simultaneously imprecise real-time information. Three dependent variables related to the passenger information system (PIS) were modeled simultaneously, including perceived waiting time, satisfaction, and the quality of rail transport. Given the likely correlation between the considered models error terms, the relationship between dependent and the independent variables was modeled with the three-stage least square (3SLS) model. We found, for instance, that there are significant association between the impacts of the real-time information and commuters’ gender, purpose of travel, frequency of travel, and various psychological feelings that commuters experienced. However, interaction results highlighted that the associations between experienced negative emotions and dependent variables are not stable but vary based on other predictors. For instance, the association between purpose of travel and increased satisfaction due to accurate real-time information varies based on the frequency of using the transport by commuters. Also, the association between feeling frustrated and increased perceived time due to imprecise real-time information differs based on the amount of anger the commuters experience due to delay. In summary, we found that commuters who experience a higher level of negative feelings are expected to assign a higher importance to the accuracy of real-time information, but those effect are varied based on their purpose of travels or other demographic characteristics.
Although social exclusion violates the basic needs of sense of control, self-esteem, meaningful existence, and belongingness, it is unknown if fear of missing out (FoMO) or attachment anxiety contributes to one’s sense of ostracism and each of these basic needs. We aimed to identify if baseline scores in attachment anxiety and/or FoMO predict how excluded an individual feels after playing an online ball-tossing game designed to include or exclude them and if these constructs tap into basic needs that ostracism has shown to threaten. A sample of 193 young adults participated in this online study. After completing measures of demographics, FoMO, and attachment anxiety, each participant played Cyberball, a virtual ball-tossing game. Under the guise of playing with two other human participants, this paradigm consists of pre-programmed conditions of either inclusion, which entails receiving 10 of the total 30 ball tosses, or exclusion, which consists of receiving the ball only twice at the beginning of the game. Participants then completed post-measures of state ostracism, basic needs, and attention checks and were debriefed regarding the nature of the Cyberball game. We found that FoMO, but not attachment anxiety, predicted how ostracized one felt. Likewise, FoMO was inversely related to control, belongingness, and meaningful existence. Attachment anxiety did not predict any of the basic needs examined in the study. We conclude FoMO may be less about the experience one misses out on and more about the fear of being excluded. Future research is needed to evaluate if people experience increases in state FoMO while excluded and if baseline mood influences our findings.
Saline formations are attractive geologic reservoirs for permanent carbon dioxide (CO2) storage. The U.S. Department of Energy's National Energy Technology Laboratory (DOE-NETL) has worked to develop and refine methods and tools for the calculation of CO2 storage potential in subsurface reservoirs. DOE-NETL's CO2-SCREEN provides an online tool for executing these storage methods. CO2 storage efficiency terms are input parameters in DOE-NETL's methods and equations embedded in the CO2-SCREEN, which assesses pore space available for CO2 storage. In this work, a modeling workflow was initiated to refine two CO2 storage efficiency terms - volumetric displacement (EV) and microscopic displacement (Ed). The models are based on new experimental relative permeability data that are specific to homogenous lithology and depositional environments of key subsurface saline formations targeted for CO2 storage. In future work, heterogenous features will be added to this initial modeling effort to update efficiency factors as described in DOE-NETL's methods and CO2-SCREEN tool. EVaccounts for the volume utilized in the reservoir under the areal plume, while Ed accounts for saturation values in the plume to assess efficiency of CO2 storage at the pore scale. The results of this work are significant in that prior values were based on a limited geologically non-specific relative permeability data set that were collected prior to 2009. Specifically, we applied numerical simulations using TOUGH3 models to update CO2 storage efficiency values for supercritical CO2 injection into brine-saturated reservoirs for three lithologies (clastics, limestone, dolomite) and six depositional environments (Marginal Marine, Strand Plain, Deltaic Complex Fluvial, Aeolian, Shallow Marine, and Reef) that have a high potential for geologic CO2 storage. Experimental relative permeability data in cores from these environments were utilized in the models with corresponding rock type/sedimentary environment. Results of this study showed that dolomite followed by limestone generated higher ranges of storage efficiency compared to clastics. The updated values provided a tighter efficiency range for clastics, lower P10 but higher P90 range for limestone, and higher P10 and P90 for dolomite. In general, tighter reservoirs with relatively low permeability and porosity were associated with higher EV and Ed, showing efficient reservoir and pore utilization in these scenarios. High reservoir pressure and temperature associated with increasing depth increased the EV, and high CO2 injection rates resulted in increases in EV and Ed, while the impact of permeability anisotropy was minimal after the 30-year injection period.
Post-translational modification of nuclear proteins through the addition of poly(ADP-ribose) (pADPr) moieties is upregulated in many metastatic cancers, where the high levels of pADPr have often been associated with poor cancer prognosis. Although the inhibitors of poly(ADP-ribose) polymerases (PARPs) have been utilized as potent anti-cancer agents, their efficacy in clinical trials varied among patient groups and has often been unpredictable. Such outcome cannot be interpreted solely by the inability to keep PARP-driven DNA repair in check. The focus of studies on PARP-driven tumorigenesis have recently been shifted toward PARP-dependent regulation of transcription. Here we utilized the controlled overexpression of poly(ADP-ribose) glycohydrolase (PARG), a sole pADPr-degrading enzyme, to investigate pADPr-dependent gene regulation in prostate cancer PC-3 cells. We demonstrated that PARG upregulation reduces pADPr levels and inhibits the expression of genes in key tumor-promoted pathways, including TNFα/NF-kB, IL6/STAT3, MYC, and KRAS signaling, the genes involved in inflammation response, especially chemokines, and endothelial-mesenchymal transition. The observed effect of PARG on transcription was consistent across all tested prostate cancer cell lines and correlates with PARG-induced reduction of clonogenic potential of PC-3 cells in vitro and a significant growth inhibition of PC-3-derived tumors in nude mice in vivo.
The present study aimed to explore whether caregivers' parental frustration mediates the relationship between parental health and children's externalizing behaviors and whether family cohesion potentially moderates this association. Data were derived from the 2016 National Survey of Children's Health (NSCH), and the total sample for the study included 50,212 adults. We tested the association between caregivers' parental health and children's externalizing behavior and whether parental frustration mediated the association between caregivers' parental health and children's externalizing behaviors. We performed a Sobel test to determine if the mediation was significant. To test the moderator, we conducted hierarchical multiple regression analyses to explore the interaction effect between caregivers' parental health and family cohesiveness on children's externalizing problems. We found a positive association between poor health conditions of caregivers and children's externalizing behavior. Our findings also showed that parental frustration mediated the association between caregivers' health conditions and children's externalizing behavior. And finally, family cohesion was found to moderate the association between caregivers' health conditions and children's externalizing behavior. Our findings suggest that to prevent or address children's externalizing behaviors, it is necessary to improve parental health, increase family cohesion, and reduce parental frustration.
The purpose of this mixed-methods study was to explore factors affecting faculty members’ motivation to use learning analytics (LA) to improve their teaching. In the quantitative phase, 107 faculty members completed an online survey about their motivation to use LA. The results showed that cost, utility, attainment value, and competence all predicted intrinsic motivation to use LA; then, in turn, positive introjected motivation and amotivation predicted faculty LA usage. In the qualitative phase, ten faculty participated in three focus groups, and seven themes emerged as key factors that affected their motivation to use LA. The themes involving motivating factors included tracking and monitoring learning activities, early alert, improve teaching effectiveness, institutional training, and support. Alternatively, demotivating factors included the cost in terms of time, lack of data competence, and the ‘un-structuredness’ of the dataset. The paper also discussed the mechanisms for increasing LA usage among faculty members to improve their teaching.
Fusion-based additive manufacturing (AM) techniques that use high energy beams, such as laser and electron beam, to layer-wise fuse and form materials, are quickly becoming mainstream in the fabrication of performance-critical metal parts. However, the vast majority of alloys currently used in industry are not compatible with fusion-based AM. One major reason is the occurrence of high thermal stress and solidification cracking resulting from the far-from-equilibrium thermal history. In this research, a novel hybrid AM process that combines directed energy deposition (DED) and layer-wise ultrasonic impact peening (UIP) is used to mitigate residual stress formation and to suppress the occurrence of solidification cracking in a hard-to-weld Inconel 100 superalloy. A series of materials characterization techniques, including 3D topography, optical microscopy, electron backscattered diffraction, and X-ray residual stress analysis, is carried out to investigate the effect of layer-wise UIP on the additively manufactured products. Three levels of UIP force, i.e., 25 N, 50 N, and 75 N, are investigated. The results indicate that there is an inverse relationship between the crack density and applied UIP force. At the highest level of UIP force, the crack density reduces to near-zero with significantly improved surface quality. To successfully suppress detrimental residual stress, the depth of the peening-affected-zone (PAZ) must be larger than the heat-affect-zone (HAZ) of laser melting.
In a large multisite cohort of Veterans who underwent Roux-en-Y gastric bypass (RYGB) or laparoscopic sleeve gastrectomy (LSG), initiation of (ie, incident) and persistence of (ie, continuation of preoperative) depression treatment are compared with matched nonsurgical controls. Bariatric surgery has been associated with short-term improvements in depression but less is known about longer term outcomes. In a retrospective cohort study, we matched 1713 Veterans with depression treatment who underwent bariatric surgery in Veterans Administration bariatric centers from fiscal year 2001 to 2016 to 15,056 nonsurgical controls using sequential stratification and examined the persistence of depression treatment via generalized estimating equations. Incidence of depression treatment was compared using Cox regression models between 2227 surgical patients and 20,939 matched nonsurgical controls without depression treatment at baseline. In surgical patients with depression treatment at baseline, the use of postsurgical depression treatment declined over time for both surgical procedures, but postsurgical patients had greater use of depression treatment at 5 years [RYGB: odds ratio=1.24, 95% confidence interval (CI): 1.04–1.49; LSG: odds ratio=1.27, 95% CI: 1.04–1.56] compared with controls. Among those without depression treatment at baseline, bariatric surgery was associated with a higher incidence of depression treatment compared with matched controls (RYGB: hazard ratio=1.34, 95% CI: 1.17–1.53; LSG: hazard ratio at 1–5 years=1.27, 95% CI: 1.10–1.47). Bariatric surgery was associated with a greater risk of postoperative incident depression treatment and greater persistence of postoperative depression treatment. Depression may worsen for some patients after bariatric surgery, so clinicians should carefully monitor their patients for depression postoperatively.
The ε4 allele of the apolipoprotein E (APOE) gene, a genetic risk factor for Alzheimer’s disease, is abundantly expressed in both the brain and periphery. Here, we present evidence that peripheral apoE isoforms, separated from those in the brain by the blood–brain barrier, differentially impact Alzheimer’s disease pathogenesis and cognition. To evaluate the function of peripheral apoE, we developed conditional mouse models expressing human APOE3 or APOE4 in the liver with no detectable apoE in the brain. Liver-expressed apoE4 compromised synaptic plasticity and cognition by impairing cerebrovascular functions. Plasma proteome profiling revealed apoE isoform-dependent functional pathways highlighting cell adhesion, lipoprotein metabolism and complement activation. ApoE3 plasma from young mice improved cognition and reduced vessel-associated gliosis when transfused into aged mice, whereas apoE4 compromised the beneficial effects of young plasma. A human induced pluripotent stem cell-derived endothelial cell model recapitulated the plasma apoE isoform-specific effect on endothelial integrity, further supporting a vascular-related mechanism. Upon breeding with amyloid model mice, liver-expressed apoE4 exacerbated brain amyloid pathology, whereas apoE3 reduced it. Our findings demonstrate pathogenic effects of peripheral apoE4, providing a strong rationale for targeting peripheral apoE to treat Alzheimer’s disease.
Second generation oxy-combustion and load following operations are accompanied by a significant (60 – 70%) reduction in combustor flue gas flow rates when compared to baseload operation. Understanding the aerodynamic influences on the fly-ash particle deposition characteristics during these novel operational scenarios are critical towards anticipating operational challenges. To fill this void, a novel Computational Fluid Dynamic (CFD) methodology in conjunction with an ash deposition module was used to model the outer ash deposition process coal during combustion of coal in AIR and O2/CO2 (70/30 vol %, OXY70) oxidizer compositions and the predictions were compared with measurements. The measured fly-ash particle size distributions (PSD) were employed as inputs to represent the particle Stokes numbers near the deposition surface accurately and the capture criterion was based on a recently proposed particle viscosity and kinetic energy (PKE) based formulation. Prediction sensitivities to the particle viscosity model and fly-ash PSD were also assessed. Deposition rate predictions in AIR were in excellent agreement with the measurements. The deposition rate enhancement (OXY70/AIR) across all scenarios were in the range 2.8 – 3.3 which was in reasonable agreement with the measured values of 2.1 – 2.4. Predicted capture efficiencies were nearly 100% across all scenarios. The calculations were repeated by employing the corresponding fly-ash composition information rather than the bulk-ash compositions and did not alter the predictions significantly. The study therefore supports the hypothesis that ash deposition rates in these novel operational scenarios are likely to be dominated by PKE.
Economic assessments are rarely applied to inland recreational fisheries for management purposes, especially when compared to fish, habitat, and creel assessments, yet economic assessments can provide critical information for management decisions. We provide a brief overview of economic value, key terminology, and existing economic techniques to address these issues. Benefit transfer, a technique used to measure economic value when an original analysis is not practicable, is conducted by drawing on existing estimates of economic value in similar contexts. We describe an application of benefit transfer to measure the economic value of several recreational fisheries in Nebraska, USA. We examine two approaches to benefit transfer—value transfer and function transfer—which we demonstrate estimate similar economic values for fishing site access but substantially different economic values for catch rate improvements at some reservoirs. We encourage agencies that are responsible for inland recreational fisheries management to consider economic assessment, especially benefit transfer, as a critical tool in the management toolbox.
The ratio of aromatic to aliphatic (AR/AL) hydrocarbons was used to investigate migration pathways in tight unconventional reservoirs. Analytical methods, including organic petrology and geochemistry, programmed pyrolysis, solid bitumen reflectance, and liptinite autofluorescence, were employed to generate regional thermal maturity maps. While AR/AL ratios are known to increase with thermal maturity, a comparison of AR/AL ratios with thermal maturity indices as well as regional thermal maturity maps shows no significant correlation to other known thermal maturity proxies (i.e., Tmax or VRo-Eq) for the Bakken Shale samples. Taking into account the concept of “size and shape” filtration from a previous study, the observed inconsistency between AR/AL ratios and thermal maturity indicators could be explained reasonably, where, based on this concept, the aliphatics are able to migrate more easily through the shale's tight media compared to the aromatics, which would remain in situ or migrate only very short distances because of their size and shape. This indicates that the inconsistency between AR/AL ratios and thermal maturity indicators is related to the disproportionate rate of migration of aliphatic and aromatic hydrocarbons in the Bakken shale. To evaluate the potential application of using AR/AL ratio chemical analyses to reveal the possible migration pathways, initial values for total organic carbon (TOC) (TOCo) and S1 (S1expelled) were calculated for the thermally immature Bakken source rock. Comparing the regional distribution maps of S1expelled and the present values of S1 could reveal the geospatial displacements of generated hydrocarbons and, therefore, the possible pathways of hydrocarbon primary migration. Comparing the AR/AL ratio regional maps with the attained migration pathway based on S1 and S1expelled regional maps reveals an acceptable correlation in terms of the general trend. In this regard, AR/AL ratios exhibit higher values in the locations of the higher concentrations of calculated S1expelled distribution maps and lower values in the location of the higher concentrations of programmed pyrolysis-derived S1 distribution maps. These outcomes confirm that AR/AL ratios could be used as a potential proxy in revealing the possible migration pathways in unconventional reservoirs.
Previous research has demonstrated the dramatic effect trauma can have on religiosity. This study sought to extend this understanding by examining how a specific trauma, rape, influences religious beliefs and behaviors as well as how religiosity influences acknowledgment of rape. Rape acknowledgment is the personal use of the label rape to describe such an experience. The process of acknowledgment and general recovery from rape can include dramatic questioning of one’s religious beliefs and marks an important potential point of intervention, especially given the majority of the US identifies as religious. A sample of 310 mostly Christian, college-aged women completed questionnaires about their personal religiosity, attitudes and beliefs, and trauma history. Results indicated those who experienced rape experienced significantly greater change in their religious beliefs compared to those who had experienced other types of traumas ( p = .015). The relationship between rape acknowledgment and extrinsic religiosity was significantly mediated by ambivalent sexism (95% CI [0.0016, 0.0694]) and the endorsement of rape myths about women lying about rape (95% CI [0.0021, 0.0691]), such that high religiosity was associated with greater acceptance of these beliefs, which was associated with a lower likelihood of acknowledgment. In all, rape was shown to significantly alter one’s participation in their religion and their understanding of their own religiosity, and religious beliefs reflective of certain beliefs fueled a mislabeling of personal experiences of rape. These findings suggest religious guidance should be offered within rape recovery programing, and support for those who experience rape should be provided specifically within religious settings.
How does language change reveal the psychological trajectories of people coping with a COVID-19 infection? This study examined writings on social media over 12 weeks from people who self-reported having tested positive for COVID-19. People used fewer words reflecting anxiety and distancing but more words indicating reinterpretation over time. The language patterns for describing the experience of COVID-19 infections differed from those for describing other unrelated topics. The findings reveal the temporal dynamics of psychological adjustment to an unfolding crisis.
Objective: To validate a customized V˙O2max Graded Exercise Test (GXT) protocol specifically to accommodate firefighters with different cardiovascular fitness levels. Methods: Career male firefighters (n = 15) completed three customized GXTs on a treadmill: one in athletic clothes and two in their bunker gear to determine maximal oxygen uptake (V˙O2max). Results: The on-duty task protocol was reliable, V˙O2max values of 40.2 ± 4.6 ml·kg·min-1 and 40.3 ± 5.3 ml·kg·min-1 between trials yielded an interclass correlation (ICC α) of 0.911 with a typical error of 1.48 ml·kg·min-1 and a coefficient of variation (CV) of 4.0%. The validity analysis indicated consistent maximal V˙O2 values for the GXTs yielding mean ICC α of 0.94 with typical error of 1.16 ml·kg·min-1 and a CV of 2.9 %. Conclusion: The customized GXT for structural firefighters has shown to be a reliable, valid, and applicable method of testing cardiovascular fitness in firefighters.
A multitude of evidence has suggested the differential incidence, prevalence and severity of asthma between males and females. A compilation of recent literature recognized sex differences as a significant non-modifiable risk factor in asthma pathogenesis. Understanding the cellular and mechanistic basis of sex differences remains complex and the pivotal point of this ever elusive quest, which remains to be clarified in the current scenario. Sex steroids are an integral part of human development and evolution while also playing a critical role in the conditioning of the immune system and thereby influencing the function of peripheral organs. Classical perspectives suggest a pre-defined effect of sex steroids, generalizing estrogens popularly under the “estrogen paradox” due to conflicting reports associating estrogen with a pro- and anti-inflammatory role. On the other hand, androgens are classified as “anti-inflammatory,” serving a protective role in mitigating inflammation. Although considered mainstream and simplistic, this observation remains valid for numerous reasons, as elaborated in the current review. Women appear immune-favored with stronger and more responsive immune elements than men. However, the remarkable female predominance of diverse autoimmune and allergic diseases contradicts this observation suggesting that hormonal differences between the sexes might modulate the normal and dysfunctional regulation of the immune system. This review illustrates the potential relationship between key elements of the immune cell system and their interplay with sex steroids, relevant to structural cells in the pathophysiology of asthma and many other lung diseases. Here, we discuss established and emerging paradigms in the clarification of observed sex differences in asthma in the context of the immune system, which will deepen our understanding of asthma etiopathology.
Perovskite solar cells (PSCs) have captured the attention of the global energy research community in recent years by showing an exponential augmentation in their performance and stability. The supremacy of the light-harvesting efficiency and wider band gap of perovskite sensitizers have led to these devices being compared with the most outstanding rival silicon-based solar cells. Nevertheless, there are some issues such as their poor lifetime stability, considerable J–V hysteresis, and the toxicity of the conventional constituent materials which restrict their prevalence in the marketplace. The poor stability of PSCs with regard to humidity, UV radiation, oxygen and heat especially limits their industrial application. This review focuses on the in-depth studies of different direct and indirect parameters of PSC device instability. The mechanism for device degradation for several parameters and the complementary materials showing promising results are systematically analyzed. The main objective of this work is to review the effectual strategies of enhancing the stability of PSCs. Several important factors such as material engineering, novel device structure design, hole-transporting materials (HTMs), electron-transporting materials (ETMs), electrode materials preparation, and encapsulation methods that need to be taken care of in order to improve the stability of PSCs are discussed extensively. Conclusively, this review discusses some opportunities for the commercialization of PSCs with high efficiency and stability.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
4,110 members
Junguk Hur
  • School of Medicine and Health Sciences
Pablo De León
  • Department of Space Studies
Vadim Rygalov
  • Department of Space Studies
Taufique H Mahmood
  • Department of Geology and Geological Engineering
Information
Address
1301 N Columbia Rd., 58202, Grand Forks, North Dakota, United States
Head of institution
Mark Kennedy, President
Website
http://www.und.edu
Phone
701-777-4970