Showing papers by "University of Nebraska Omaha published in 2018"

Maximizing Specific Loss Power for Magnetic Hyperthermia by Hard-Soft Mixed Ferrites.

Abstract: Maximized specific loss power and intrinsic loss power approaching theoretical limits for alternating-current (AC) magnetic-field heating of nanoparticles are reported. This is achieved by engineering the effective magnetic anisotropy barrier of nanoparticles via alloying of hard and soft ferrites. 22 nm Co0.03 Mn0.28 Fe2.7 O4 /SiO2 nanoparticles reach a specific loss power value of 3417 W g-1metal at a field of 33 kA m-1 and 380 kHz. Biocompatible Zn0.3 Fe2.7 O4 /SiO2 nanoparticles achieve specific loss power of 500 W g-1metal and intrinsic loss power of 26.8 nHm2 kg-1 at field parameters of 7 kA m-1 and 380 kHz, below the clinical safety limit. Magnetic bone cement achieves heating adequate for bone tumor hyperthermia, incorporating an ultralow dosage of just 1 wt% of nanoparticles. In cellular hyperthermia experiments, these nanoparticles demonstrate high cell death rate at low field parameters. Zn0.3 Fe2.7 O4 /SiO2 nanoparticles show cell viabilities above 97% at concentrations up to 500 µg mL-1 within 48 h, suggesting toxicity lower than that of magnetite.

Debriefs: Teams learning from doing in context.

Abstract: Debriefs are a type of work meeting in which teams discuss, interpret, and learn from recent events during which they collaborated. In a variety of forms, debriefs are found across a wide range of organizational types and settings. Well-conducted debriefs can improve team effectiveness by 25% across a variety of organizations and settings. For example, the U.S. military adopted debriefs decades ago to promote learning and performance across the various services. Subsequently, debriefs have been introduced in the medical field, the fire service, aviation, education, and in a variety of organizational training and simulation environments. After a discussion of various purposes for which debriefs have been used, we proceed with a historical review of development of the concepts and use in industries and contexts. We then review the psychological factors relevant to debrief effectiveness and the outcomes for individuals, teams, and organizations that deploy debriefs. Future directions of particular interest to team researchers across a variety of psychological disciplines are presented along with a review of how best to implement debriefs from a practical perspective. (PsycINFO Database Record

Multicenter Phase II Study of Sequential Brentuximab Vedotin and Doxorubicin, Vinblastine, and Dacarbazine Chemotherapy for Older Patients With Untreated Classical Hodgkin Lymphoma.

Abstract: PurposeTo improve the curability of older patients with newly diagnosed Hodgkin lymphoma.Patients and MethodsWe conducted a multicenter phase II study that administered brentuximab vedotin (Bv) sequentially before and after standard doxorubicin, vinblastine, and dacarbazine (AVD) for untreated patients with Hodgkin lymphoma age 60 years or older. After two lead-in doses of single-agent Bv (1.8 mg/kg once every 3 weeks), patients received six cycles of AVD chemotherapy followed by four consolidative doses of Bv in responding patients.ResultsPatient characteristics included median age of 69 years (range, 60 to 88 years), 63% male, median Eastern Cooperative Oncology Group performance status 1, 81% stage III to IV disease, 60% International Prognostic Score 3 to 7, median Cumulative Illness Rating Scale-Geriatric comorbidity score of 7 (52% grade 3 to 4); and 12% had loss of instrumental activities of daily living at diagnosis. Thirty-seven (77%) of 48 patients completed six cycles of AVD, and 35 patients (7...

3D Bioprinting of Breast Cancer Models for Drug Resistance Study

Abstract: Adipose-derived mesenchymal stem/stromal cells (ADMSC) are one of the major stromal cells in the breast cancer microenvironment that promote cancer progression. Previous studies on the effects of ADMSC on breast cancer metastasis and drug resistance, using two-dimensional (2D) cultures, remained inconclusive. In the present study, we compared cocultured ADMSC and human epidermal receptor 2 positive breast primary breast cancer cells (21PT) in 2D and three-dimensional (3D) cultures and then examined their response to doxorubicin (DOX). We examined 3D bioprinted constructs with breast cancer cells in the middle and ADMSC in the edge region, which were made by using dual hydrogel-based bioinks. We found that the percentage of cleaved Caspase-3 positive cells was significantly lower in the bioprinted constructs with ADMSC and 21PT than that in the cancer cell alone constructs, in response to low DOX dose. We further increased the thickness of the ADMSC layers to mimic the status of obesity and then examined the effect of ADMSC thickness on DOX resistance and lysyl oxidase (LOX) secretion. In the moderate and thick-layered ADMSC constructs, significantly more cells were stained negative for cleaved Caspase-3, indicating less apoptosis. Both ADMSC and 21PT intrinsically expressed LOX, regardless of changes in thickness or DOX administration. Notably, treatment with a LOX inhibitor significantly decreased the stiffness in the ADMSC region but did not affect the stiffness in the 21PT region. In addition, LOX inhibitor treatment enhanced DOX sensitivity of 21PT in the bioprinted constructs, as seen by a decrease in LOX secretion and downregulation of adenosine triphosphate-binding cassette transporter gene expression. Taken together, we demonstrate that 3D bioprinted these breast cancer models faithfully reproduce in vivo conditions and should provide better models for examining breast cancer biology and for screening for drug discoveries.

Comparison of Wearable Trackers' Ability to Estimate Sleep.

Abstract: Tracking physical activity and sleep patterns using wearable trackers has become a current trend. However, little information exists about the comparability of wearable trackers measuring sleep. This study examined the comparability of wearable trackers for estimating sleep measurement with a sleep diary (SD) for three full nights. A convenience sample of 78 adults were recruited in this research with a mean age of 27.6 ± 11.0 years. Comparisons between wearable trackers and sleep outcomes were analyzed using the mean absolute percentage errors, Pearson correlations, Bland–Altman Plots, and equivalent testing. Trackers that showed the greatest equivalence with the SD for total sleep time were the Jawbone UP3 and Fitbit Charge Heart Rate (effect size = 0.09 and 0.23, respectively). The greatest equivalence with the SD for time in bed was seen with the SenseWear Armband, Garmin Vivosmart, and Jawbone UP3 (effect size = 0.09, 0.16, and 0.07, respectively). Some of the wearable trackers resulted in closer approximations to self-reported sleep outcomes than a previously sleep research-grade device, these trackers offer a lower-cost alternative to tracking sleep in healthy populations.

The development and application of bioinformatics core competencies to improve bioinformatics training and education.

Abstract: Bioinformatics is recognized as part of the essential knowledge base of numerous career paths in biomedical research and healthcare. However, there is little agreement in the field over what that knowledge entails or how best to provide it. These disagreements are compounded by the wide range of populations in need of bioinformatics training, with divergent prior backgrounds and intended application areas. The Curriculum Task Force of the International Society of Computational Biology (ISCB) Education Committee has sought to provide a framework for training needs and curricula in terms of a set of bioinformatics core competencies that cut across many user personas and training programs. The initial competencies developed based on surveys of employers and training programs have since been refined through a multiyear process of community engagement. This report describes the current status of the competencies and presents a series of use cases illustrating how they are being applied in diverse training contexts. These use cases are intended to demonstrate how others can make use of the competencies and engage in the process of their continuing refinement and application. The report concludes with a consideration of remaining challenges and future plans.

Bioinformatics core competencies for undergraduate life sciences education.

Abstract: Although bioinformatics is becoming increasingly central to research in the life sciences, bioinformatics skills and knowledge are not well integrated into undergraduate biology education. This curricular gap prevents biology students from harnessing the full potential of their education, limiting their career opportunities and slowing research innovation. To advance the integration of bioinformatics into life sciences education, a framework of core bioinformatics competencies is needed. To that end, we here report the results of a survey of biology faculty in the United States about teaching bioinformatics to undergraduate life scientists. Responses were received from 1,260 faculty representing institutions in all fifty states with a combined capacity to educate hundreds of thousands of students every year. Results indicate strong, widespread agreement that bioinformatics knowledge and skills are critical for undergraduate life scientists as well as considerable agreement about which skills are necessary. Perceptions of the importance of some skills varied with the respondent's degree of training, time since degree earned, and/or the Carnegie Classification of the respondent's institution. To assess which skills are currently being taught, we analyzed syllabi of courses with bioinformatics content submitted by survey respondents. Finally, we used the survey results, the analysis of the syllabi, and our collective research and teaching expertise to develop a set of bioinformatics core competencies for undergraduate biology students. These core competencies are intended to serve as a guide for institutions as they work to integrate bioinformatics into their life sciences curricula.

Modeling Temporal Interaction Dynamics in Organizational Settings

Abstract: Most workplace phenomena take place in dynamic social settings and emerge over time, and scholars have repeatedly called for more research into the temporal dynamics of organizational behavior. One reason for this persistent research gap could be that organizational scholars are not aware of the methodological advances that are available today for modeling temporal interactions and detecting behavioral patterns that emerge over time. To facilitate such awareness, this Methods Corner contribution provides a hands-on tutorial for capturing and quantifying temporal behavioral patterns and for leveraging rich interaction data in organizational settings. We provide an overview of different approaches and methodologies for examining temporal interaction patterns, along with detailed information about the type of data that needs to be gathered in order to apply each method as well as the analytical steps (and available software options) involved in each method. Specifically, we discuss and illustrate lag sequential analysis, pattern analysis, statistical discourse analysis, and visualization methods for identifying temporal patterns in interaction data. We also provide key takeaways for integrating these methods more firmly in the field of organizational research and for moving interaction analytical research forward.

Repeatability and reliability of exploratory behavior in proactive and reactive zebrafish, Danio rerio.

Abstract: Behavioral responses to novel situations often vary and can belong to a suite of correlated behaviors. Characteristic behaviors of different personality types (e.g. stress coping styles) are generally consistent across contexts and time. Here, we compare the repeatability and reliability of exploratory behaviors between zebrafish strains selectively bred to display contrasting behavioral responses to stressors that represent the proactive-reactive axis. Specifically, we measure exploratory behavior of individual fish in an open field test over five weeks. We quantified the stationary time, average swimming speed and time spent by a fish in the center area. We found a number of strain differences for each behavioral measure. Stationary time was the most repeatable and reliable measure for assessing proactive-reactive behavioral differences. Reactive zebrafish generally showed the highest reliability and repeatability of exploratory behavior compared to proactive zebrafish and a separate wild caught strain. Given the increased interest in the evolutionary consequences and proximate mechanisms of consistent individual differences, it will be important to continue to investigate how different selective pressures may influence expression of stress coping styles and their effects on the consistency of an animal’s behavior.

Characterization of stem cell and cancer stem cell populations in ovary and ovarian tumors

Abstract: Ovarian cancer is a complicated malady associated with cancer stem cells (CSCs) contributing to 238,700 estimated new cases and 151,900 deaths per year, worldwide. CSCs comprise a tiny fraction of tumor-bulk responsible for cancer recurrence and eventual mortality. CSCs or tumor initiating cells are responsible for self-renewal, differentiation and proliferative potential, tumor initiation capability, its progression, drug resistance and metastatic spread. Although several biomarkers are implicated in these processes, their distribution within the ovary and association with single cell type has neither been established nor demonstrated across ovarian tumor developmental stages. Therefore, precise identification, thorough characterization and effective targeted destruction of dormant and highly proliferating potent CSC populations is an immediate need. In view of this, distribution of various CSC (ALDH1/2, C-KIT, CD133, CD24 and CD44) and cell proliferation (KI67) specific markers in the ovarian surface epithelium (OSE) and cortex regions in normal ovary, and benign, borderline and high grade metastatic ovarian tumors by immuno-histochemistry and confocal microscopy was studied. We further confirmed their expression by RT-PCR analysis. Co-expression analysis of stem cell (OCT4, SSEA4) and CSC (ALDH1/2, CD44 and LGR5) markers with proliferation marker (KI67) in HG tumors revealed dual positive proliferating stem and CSCs, few non-proliferating stem/CSC (SSEA4+/KI67− and ALDH1/2+/KI67−) and only KI67+ cells in cortex, signifying dynamic populations and interesting cellular hierarchy in cortex region. Smaller spherical (≤ 5 μm) and larger spindle/elliptical shaped (~ 10 μm) cell populations with high nucleo-cytoplasmic ratio were detected across all samples (including normal ovaries) but with variable distribution and characteristic stage-wise marker expression across different tumor stages. Diverse stem and CSC populations expressing characteristic markers revealing distinct phenotypes (spherical ≤5 μm and spindle/elliptical ~ 10 μm) were distributed within different tumor stages studied signifying dynamic and probable functional hierarchy within these cell types. Involvement of extra-ovarian sites of origin of stem and CSCs requires rigorous evaluation. Quantitative analysis of potent CSC populations, their mechanisms and pathways for self-renewal, chemo-resistance, metastatic spread etc. with respect to various markers studied, will provide better insights and targets for developing effective therapeutics to prevent metastasis and eventually help improve patient mortality.

An Assessment of the Exporting Literature: Using Theory and Data to Identify Future Research Directions

Abstract: Exporting research is an established facet of the field of international marketing. That stated, the radical increase in recent export activity necessitates a sustained research effort devoted to the topic. In this article, the authors provide a qualitative review of the core theoretical exporting areas and evaluate the exporting domain quantitatively over six decades (1958–2016). For the quantitative analysis, they use multidimensional scaling and apply established bibliometric principles to offer an understanding of the field and to provide suggestions for future exporting research. For the evaluations, the authors used data from 830 articles with 52,191 citations from 35 journals. Using cocitation analysis as the basis to evaluate the data, they propose a series of intellectual structure implications on exporting that relate to internationalization process stages, dynamic capabilities, knowledge scarcity, social networks, export marketing strategy, absorptive capacity and learning, and nonlinea...

Age‐related endothelial dysfunction in human skeletal muscle feed arteries: the role of free radicals derived from mitochondria in the vasculature

Abstract: This work was supported by NIH Heart, Lung, Blood Institute grants (HL‐091830) and Veterans Affairs Rehabilitation Research and Development Merit (E6910‐R).

Administrative racism: Public administration education and race

Abstract: Public administration has an ethical problem with race and racism. Researchers find that race is a nervous area of government public administrators avoid confronting, resulting in their eschewing d...

Is the Number of Citizens Fatally Shot by Police Increasing in the Post-Ferguson Era?

Abstract: This study examines whether the number of citizens fatally shot by police in the United States has changed significantly since the shooting of Michael Brown in Ferguson, Missouri. Using longitudinal data compiled by killedbypolice.net, we use an interrupted time-series design to test the effect of events in Ferguson on fatal shootings by police. Our analyses reveal that the number of citizens killed by police is temporally unstable, exhibiting random short-term fluctuations that are often misinterpreted as evidence of substantively meaningful trends. However, after testing a variety of model specifications, we find no evidence that the number of fatal police shootings either increased or decreased post-Ferguson. Claims to the contrary are based on weak analyses of short-term trends.

The influence of conversational agent embodiment and conversational relevance on socially desirable responding

Abstract: Conversational agents (CAs) are becoming an increasingly common component in a wide range of information systems A great deal of research to date has focused on enhancing traits that make CAs more humanlike However, few studies have examined the influence such traits have on information disclosure This research builds on self-disclosure, social desirability, and social presence theories to explain how CA anthropomorphism affects disclosure of personally sensitive information Taken together, these theories suggest that as CAs become more humanlike, the social desirability of user responses will increase In this study, we use a laboratory experiment to examine the influence of two elements of CA design—conversational relevance and embodiment—on the answers people give in response to sensitive and non-sensitive questions We compare the responses given to various CAs to those given in a face-to-face interview and an online survey The results show that for sensitive questions, CAs with better conversational abilities elicit more socially desirable responses from participants, with a less significant effect found for embodiment These results suggest that for applications where eliciting honest answers to sensitive questions is important, CAs that are “better” in terms of humanlike realism may not be better for eliciting truthful responses to sensitive questions

Testing a Social Schematic Model of Police Procedural Justice

Abstract: Procedural justice theory increasingly guides policing reforms in the United States and abroad. Yet the primary sources of perceived police procedural justice are still unclear. Building on social ...

Bi-articular Knee-Ankle-Foot Exoskeleton Produces Higher Metabolic Cost Reduction than Weight-Matched Mono-articular Exoskeleton.

Abstract: The bi-articular m. gastrocnemius and the mono-articular m. soleus have different and complementary functions during walking. Several groups are starting to use these biological functions as inspiration to design prostheses with bi-articular actuation components to replace the function of the m. gastrocnemius. Simulation studies indicate that a bi-articular configuration and spring that mimic the m. gastrocnemius could be beneficial for orthoses or exoskeletons. Our aim was to test the effect of a bi-articular and spring configuration that mimics the m. gastrocnemius and compare this to a no-spring and mono-articular configuration. We tested nine participants during walking with knee-ankle-foot exoskeletons with dorsally mounted pneumatic muscle actuators. In the bi-articular plus spring condition the pneumatic muscles were attached to the thigh segment with an elastic cord. In the bi-articular no-spring condition the pneumatic muscles were also attached to the thigh segment but with a non-elastic cord. In the mono-articular condition the pneumatic muscles were attached to the shank segment. We found the highest reduction in metabolic cost of 13% compared to walking with the exoskeleton powered-off in the bi-articular plus spring condition. Possible explanations for this could be that the exoskeleton delivered the highest total positive work in this condition at the ankle and the knee and provided more assistance during the isometric phase of the biological plantarflexors. As expected we found that the bi-articular conditions reduced m. gastrocnemius EMG more than the mono-articular condition but this difference was not significant. We did not find that the mono-articular condition reduces the m. soleus EMG more than the bi-articular conditions. Knowledge of specific effects of different exoskeleton configurations on metabolic cost and muscle activation could be useful for providing customized assistance for specific gait impairments.

Same Spiral, Different Day? Testing the Spiral of Silence Across Issue Types

Abstract: Although research has tested the spiral of silence theory using a variety of issues, little attention is paid to how the nature of the issues affects the spiral of silence processes. This study adopts issue typologies provided by Yeric and Todd and recommended by Salmon and Glynn to test the theory using three issues: immigration (transitory), gay marriage (emerging), and abortion (enduring). Using a nationwide survey of Facebook users (N = 1,046), this study investigates how the nature of issues influences the dynamics of the spiral of silence processes. Results identify issue-specific differences, especially regarding the opinion congruency. Theoretical implications for future tests of the spiral of silence theory and public opinion research are discussed.

The Ethnographic Method in CSR Research: The Role and Importance of Methodological Fit:

Abstract: Corporate social responsibility (CSR) research has burgeoned in the past several decades. Despite significant advances, our review of the literature reveals a problematic gap: We know little about ...

Do We Really Need Another Meeting? The Science of Workplace Meetings:

Abstract: Meetings are routine in organizations, but their value is often questioned by the employees who must sit through them daily. The science of meetings that has emerged as of late provides necessary d...

Inter-vendor reproducibility of left and right ventricular cardiovascular magnetic resonance myocardial feature-tracking.

Abstract: Aim Since cardiovascular magnetic resonance feature-tracking (CMR-FT) has been demonstrated to be of incremental clinical merit we investigated the interchangeability of global left and right ventricular strain parameters between different CMR-FT software solutions. Material and methods CMR-cine images of 10 patients without significant reduction in LVEF and RVEF and 10 patients with a significantly impaired systolic function were analyzed using two different types of FT-software (TomTec, Germany; QStrain, Netherlands). Global longitudinal strains (LV GLS, RV GLS), global left ventricular circumferential (GCS) and radial strains (GRS) were assessed. Differences in intra- and inter-observer variability within and between software types based on single and up to three repeated and subsequently averaged measurements were evaluated. Results Inter-vendor agreement was highest for GCS followed by LV GLS. GRS and RV GLS showed lower inter-vendor agreement. Variability was consistently higher in healthy volunteers as compared to the patient group. Intra-vendor reproducibility was excellent for GCS, LV GLS and RV GLS, but lower for GRS. The impact of repeated measurements was most pronounced for GRS and RV GLS on an intra-vendor level. Conclusion Cardiac pathology has no influence on CMR-FT reproducibility. LV GLS and GCS qualify as the most robust parameters within and between individual software types. Since both parameters can be interchangeably assessed with different software solutions they may enter the clinical arena for optimized diagnostic and prognostic evaluation of cardiovascular morbidity and mortality in various pathologies.