Showing papers by "University of Nebraska Omaha published in 2015"

Non-Hodgkin lymphoma: diagnosis and treatment.

Abstract: Non-Hodgkin lymphomas are lymphoid malignant neoplasms with diverse biological and clinical behavior. Patients typically present with persistent painless lymphadenopathy, but some patients may present with constitutional symptoms or with involvement of organs other than the lymphoid and hematopoietic system. An accurate diagnosis, careful staging of the disease, and identification of adverse prognostic factors form the basis of treatment selection. Patients commonly receive chemoimmunotherapy as initial treatment, and radiation therapy may be added if patients have early-stage disease. Most patients respond well to treatment, but relapses are frequent and additional therapies including stem cell transplant are often needed. Because many subtypes of lymphoma remain incurable with current management strategies, clinical trials are in progress to identify novel therapies with promising activity in this disease.

Does Economic Policy Uncertainty Predict Exchange Rate Returns and Volatility? Evidence from a Nonparametric Causality-in-Quantiles Test

Abstract: Recent studies have analysed the ability of measures of uncertainty to predict movements in macroeconomic and financial variables. The objective of this paper is to employ the recently proposed nonparametric causality-in-quantiles test to analyse the predictability of returns and volatility of sixteen U.S. dollar-based exchange rates (for both developed and developing countries) over the monthly period of 1999:01-2012:03, based on information provided by a news-based measure of relative uncertainty, i.e., the differential between domestic and U.S. uncertainties. The causality-in-quantile approach allows us to test for not only causality-in-mean (1st moment), but also causality that may exist in the tails of the joint distribution of the variables. In addition, we are also able to investigate causality-in-variance (volatility spillovers) when causality in the conditional-mean may not exist, yet higher order interdependencies might emerge. We motivate our analysis by employing tests for nonlinearity. These tests detect nonlinearity, as well as the existence of structural breaks in the exchange rate returns, and in its relationship with the EPU differential, implying that the Granger causality tests based on a linear framework is likely to suffer from misspecification. The results of our nonparametric causality-in-quantiles test indicate that for seven exchange rates EPU differentials have a causal impact on the variance of exchange rate returns but not on the returns themselves at all parts of the conditional distribution. We also find that EPU differentials have predictive ability for both exchange rate returns as well as the return variance over the entire conditional distribution for four exchange rates.

Landscape heterogeneity drives contrasting concentration–discharge relationships in shale headwater catchments

Abstract: Solute concentrations in stream water vary with discharge in patterns that record complex feedbacks between hydrologic and biogeochemical processes. In a comparison of three shale-underlain headwater catchments located in Pennsylvania, USA (the forested Shale Hills Critical Zone Observatory), and Wales, UK (the peatland-dominated Up- per Hafren and forest-dominated Upper Hore catchments in the Plynlimon forest), dissimilar concentration-discharge (C-Q) behaviors are best explained by contrasting landscape distributions of soil solution chemistry - especially dissolved organic carbon (DOC) - that have been established by pat- terns of vegetation and soil organic matter (SOM). Specif- ically, elements that are concentrated in organic-rich soils due to biotic cycling (Mn, Ca, K) or that form strong com- plexes with DOC (Fe, Al) are spatially heterogeneous in pore waters because organic matter is heterogeneously dis- tributed across the catchments. These solutes exhibit non- chemostatic behavior in the streams, and solute concentra- tions either decrease (Shale Hills) or increase (Plynlimon) with increasing discharge. In contrast, solutes that are con- centrated in soil minerals and form only weak complexes with DOC (Na, Mg, Si) are spatially homogeneous in pore waters across each catchment. These solutes are chemo- static in that their stream concentrations vary little with stream discharge, likely because these solutes are released quickly from exchange sites in the soils during rainfall events. Furthermore, concentration-discharge relationships of non-chemostatic solutes changed following tree harvest in the Upper Hore catchment in Plynlimon, while no changes were observed for chemostatic solutes, underscoring the role of vegetation in regulating the concentrations of certain ele- ments in the stream. These results indicate that differences in the hydrologic connectivity of organic-rich soils to the stream drive differences in concentration behavior between catchments. As such, in catchments where SOM is dom- inantly in lowlands (e.g., Shale Hills), we infer that non- chemostatic elements associated with organic matter are re- leased to the stream early during rainfall events, whereas in catchments where SOM is dominantly in uplands (e.g., Plyn- limon), these non-chemostatic elements are released later during rainfall events. The distribution of SOM across the landscape is thus a key component for predictive models of solute transport in headwater catchments.

"was it something i said?" "no, it was something you posted!" A study of the spiral of silence theory in social media contexts

Abstract: New media technologies make it necessary for scholars to reassess mass communication theories developed among legacy media. One such theory is the spiral of silence theory originally proposed by Noelle-Neumann in the 1970s. Increasing diversity of media content, selectivity, social networking site (SNS) interactivity, and the potential for anonymity have posed various challenges to its theoretical assumptions. While application of the spiral of silence in SNS contexts has been theorized, its empirical testing is scarce. To fill this void, the Pew 2012 Search, Social Networks, and Politics survey is used to test the theory. Results reveal that encountering agreeable political content predicts speaking out, while encountering disagreeable postings stifles opinion expression, supporting the spiral of silence theory in the SNS environment. However, certain uses of SNSs and psychological factors demonstrate a liberating effect on opinion expression.

Neuropsychological changes following deep brain stimulation surgery for Parkinson's disease: comparisons of treatment at pallidal and subthalamic targets versus best medical therapy

Abstract: Background Deep brain stimulation (DBS) improves motor symptoms in Parkinson9s disease (PD), but questions remain regarding neuropsychological decrements sometimes associated with this treatment, including rates of statistically and clinically meaningful change, and whether there are differences in outcome related to surgical target. Methods Neuropsychological functioning was assessed in patients with Parkinson9s disease (PD) at baseline and after 6 months in a prospective, randomised, controlled study comparing best medical therapy (BMT, n=116) and bilateral deep brain stimulation (DBS, n=164) at either the subthalamic nucleus (STN, n=84) or globus pallidus interna (GPi, n=80), using standardised neuropsychological tests. Measures of functional outcomes were also administered. Results Comparison of the two DBS targets revealed few significant group differences. STN DBS was associated with greater mean reductions on some measures of processing speed, only one of which was statistically significant in comparison with stimulation of GPi. GPi DBS was associated with lower mean performance on one measure of learning and memory that requires mental control and cognitive flexibility. Compared to the group receiving BMT, the combined DBS group had significantly greater mean reductions at 6-month follow-up in performance on multiple measures of processing speed and working memory. After calculating thresholds for statistically reliable change from data obtained from the BMT group, the combined DBS group also displayed higher rates of decline in neuropsychological test performance. Among study completers, 18 (11%) study participants receiving DBS displayed reliable decline by multiple indicators in two or more cognitive domains, a significantly higher rate than in the BMT group (3%). This multi-domain cognitive decline was associated with less beneficial change in subjective ratings of everyday functioning and quality of life (QOL). The multi-domain cognitive decline group continued to function at a lower level at 24-month follow-up. Conclusions In those with PD, the likelihood of significant decline in neuropsychological functioning increases with DBS, affecting a small minority of patients who also appear to respond less optimally to DBS by other indicators of QOL. Trial registration number NCT00056563 and NCT01076452.

Transcriptomic variation of hepatopancreas reveals the energy metabolism and biological processes associated with molting in Chinese mitten crab, Eriocheir sinensis

Abstract: Molting is a critical developmental process for crustaceans, yet the underlying molecular mechanism is unknown. In this study, we used RNA-Seq to investigate transcriptomic profiles of the hepatopancreas and identified differentially expressed genes at four molting stages of Chinese mitten crab (Eriocheir sinensis). A total of 97,398 transcripts were assembled, with 31,900 transcripts annotated. Transcriptomic comparison revealed 1,189 genes differentially expressed amongst different molting stages. We observed a pattern associated with energy metabolism and physiological responses during a molting cycle. In specific, differentially expressed genes enriched in postmolt were linked to energy consumption whereas genes enriched in intermolt were related to carbohydrates, lipids metabolic and biosynthetic processes. In premolt, a preparation stage for upcoming molting and energy consumption, highly expressed genes were enriched in response to steroid hormone stimulus and immune system development. The expression profiles of twelve functional genes detected via RNA-Seq were corroborated through real-time RT-PCR assay. Together, our results, including assembled transcriptomes, annotated functional elements and enriched differentially expressed genes amongst different molting stages, provide novel insights into the functions of the hepatopancreas in energy metabolism and biological processes pertaining to molting in crustaceans.

Clinically Available Medicines Demonstrating Anti-Toxoplasma Activity

Abstract: Toxoplasma gondii is an apicomplexan parasite of humans and other mammals, including livestock and companion animals. While chemotherapeutic regimens, including pyrimethamine and sulfadiazine regimens, ameliorate acute or recrudescent disease such as toxoplasmic encephalitis or ocular toxoplasmosis, these drugs are often toxic to the host. Moreover, no approved options are available to treat infected women who are pregnant. Lastly, no drug regimen has shown the ability to eradicate the chronic stage of infection, which is characterized by chemoresistant intracellular cysts that persist for the life of the host. In an effort to promote additional chemotherapeutic options, we now evaluate clinically available drugs that have shown efficacy in disease models but which lack clinical case reports. Ideally, less-toxic treatments for the acute disease can be identified and developed, with an additional goal of cyst clearance from human and animal hosts.

Graphdiyne-metal contacts and graphdiyne transistors

Abstract: Graphdiyne was prepared on a metal surface, and the preparation of devices using it inevitably involves its contact with metals. Using density functional theory with dispersion correction, we systematically studied, for the first time, the interfacial properties of graphdiyne that is in contact with a series of metals (Al, Ag, Cu, Au, Ir, Pt, Ni, and Pd). Graphdiyne forms an n-type Ohmic or quasi-Ohmic contact with Al, Ag, and Cu, while it forms a Schottky contact with Pd, Au, Pt, Ni, and Ir (at the source/drain-channel interface), with high Schottky barrier heights of 0.21, 0.46 (n-type), 0.30, 0.41, and 0.46 (p-type) eV, respectively. A graphdiyne field effect transistor (FET) with Al electrodes was simulated using quantum transport calculations. This device exhibits an on–off ratio up to 104 and a very large on-state current of 1.3 × 104 mA mm−1 in a 10 nm channel length. Thus, a new prospect has opened up for graphdiyne in high performance nanoscale devices.

The influence of auditory-motor coupling on fractal dynamics in human gait

Abstract: Humans exhibit an innate ability to synchronize their movements to music. The field of gait rehabilitation has sought to capitalize on this phenomenon by invoking patients to walk in time to rhythmic auditory cues with a view to improving pathological gait. However, the temporal structure of the auditory cue, and hence the temporal structure of the target behavior has not been sufficiently explored. This study reveals the plasticity of auditory-motor coupling in human walking in relation to ‘complex’ auditory cues. The authors demonstrate that auditory-motor coupling can be driven by different coloured auditory noise signals (e.g. white, brown), shifting the fractal temporal structure of gait dynamics towards the statistical properties of the signals used. This adaptive capability observed in whole-body movement, could potentially be harnessed for targeted neuromuscular rehabilitation in patient groups, depending on the specific treatment goal.

Individual and Environmental Sources of Work Stress Among Prison Officers

Abstract: Work stress has been linked to a number of negative outcomes for employees and organizations. Drawing from the Job Demand–Control (–Support) model, we examined the influences of work stress among more than 1,800 prison officers working in 45 prisons across Ohio and Kentucky. Multilevel analyses revealed that individual factors such as experiencing victimization and greater job demands were related to more stress among prison officers, whereas perceived control over inmates and support from coworkers and supervisors were associated with less stress. Facility violence was also linked to higher levels of officer stress across prisons.

Empirical Validation and Application of the Computing Attitudes Survey.

Abstract: Student attitudes play an important role in shaping learning experiences. However, few validated instruments exist for measuring student attitude development in a discipline-specific way. In this paper, we present the design, development, and validation of the computing attitudes survey (CAS). The CAS is an extension of the Colorado Learning Attitudes about Science Survey and measures novice to expert attitude shifts about the nature of knowledge and problem solving in computer science. Factor analysis with a large, multi-institutional data-set identified and confirmed five subscales on the CAS related to different facets of attitudes measured on the survey. We then used the CAS in a pre–post format to demonstrate its usefulness in studying attitude shifts during CS1 courses and its responsiveness to varying instructional conditions. The most recent version of the CAS is provided in its entirety along with a discussion of the conditions under which its validity has been demonstrated.

Gamma-tocotrienol attenuates high-fat diet-induced obesity and insulin resistance by inhibiting adipose inflammation and M1 macrophage recruitment

Abstract: Gamma-tocotrienol attenuates high-fat diet-induced obesity and insulin resistance by inhibiting adipose inflammation and M1 macrophage recruitment

Inquiry-Based Learning and the Flipped Classroom Model.

Abstract: The flipped classroom model of teaching can be an ideal venue for turning a traditional classroom into an engaging, inquiry-based learning (IBL) environment. In this paper, we discuss how two instr...

The impact of the 2008–2009 crisis on the automotive industry: global trends and firm-level effects in Central Europe

Abstract: This article examines the impact of the 2008–2009 economic crisis on the automotive industry. The uneven nature of the crisis contributed to the gradual shift in production from traditional core areas of the global automobile industry to selected less developed economies. In this context, the paper analyses the firm-level effects of the economic crisis in the Czech and Slovak automotive industries as two examples of automotive industry peripheries that were integrated in the European automobile production system and experienced rapid production increases after 1990. The analysis draws on unique data collected during a survey of 274 Czech-based and 133 Slovak-based automotive firms conducted in autumn 2009 and spring 2010, 98 company interviews conducted with automotive firms in Czechia in 2010 and 2011, and 30 interviews conducted in Slovakia in 2011. Changes in revenues, production and employment during the economic crisis are compared between Czechia and Slovakia, and are analysed according to ownership...

Abnormal accumulation of desmin in gastrocnemius myofibers of patients with peripheral artery disease: associations with altered myofiber morphology and density, mitochondrial dysfunction and impaired limb function.

Abstract: Patients with peripheral artery disease (PAD) develop a myopathy in their ischemic lower extremities, which is characterized by myofiber degeneration, mitochondrial dysfunction and impaired limb function. Desmin, a protein of the cytoskeleton, is central to maintenance of the structure, shape and function of the myofiber and its organelles, especially the mitochondria, and to translation of sarcomere contraction into muscle contraction. In this study, we investigated the hypothesis that disruption of the desmin network occurs in gastrocnemius myofibers of PAD patients and correlates with altered myofiber morphology, mitochondrial dysfunction, and impaired limb function. Using fluorescence microscopy, we evaluated desmin organization and quantified myofiber content in the gastrocnemius of PAD and control patients. Desmin was highly disorganized in PAD but not control muscles and myofiber content was increased significantly in PAD compared to control muscles. By qPCR, we found that desmin gene transcripts were increased in the gastrocnemius of PAD patients as compared with control patients. Increased desmin and desmin gene transcripts in PAD muscles correlated with altered myofiber morphology, decreased mitochondrial respiration, reduced calf muscle strength and decreased walking performance. In conclusion, our studies identified disruption of the desmin system in gastrocnemius myofibers as an index of the myopathy and limitation of muscle function in patients with PAD.

Participate or else!: The effect of participation in decision-making in meetings on employee engagement.

Abstract: In the scope of organizational life, few events are as universal or as influential as workplace meetings. In this study, we focused our attention on better understanding the relationship between meetings processes and postmeeting outcomes. More specifically, we investigated the relationship between participation in decision making (PDM) in meetings and employee engagement, after controlling for the impact of meeting size and other demographic variables. We examined this from a theoretical perspective, providing particular consideration to the underlying basis of social exchange theory and norms of reciprocity at work in this relationship. Using a sample of working adults in the United States who were employees of organizations and attend meetings regularly, we found that PDM in meetings is related to employee engagement, even after controlling for job level, meeting size, tenure, and age. In addition, perceived supervisor support moderates the relationship between PDM in meetings and employee engagement, such that the positive relationship is stronger when perceived supervisor support is high. Further, meeting load also moderates the relationship between PDM in meetings and employee engagement, such that the positive relationship is stronger when meeting load is high. This study is unique in its examination of how characteristics of the meeting setting may influence postmeeting outcomes such as employee engagement. Taken together, the findings suggest that PDM in meetings is associated with employee engagement, under certain conditions that are discussed.

Multimodal neuroimaging evidence of alterations in cortical structure and function in HIV‐infected older adults

Abstract: Combination antiretroviral therapy transformed human immunodeficiency virus (HIV)-infection from a terminal illness to a manageable condition, but these patients remain at a significantly elevated risk of developing cognitive impairments and the mechanisms are not understood. Some previous neuroimaging studies have found hyperactivation in frontoparietal networks of HIV-infected patients, whereas others reported aberrations restricted to sensory cortices. In this study, we utilize high-resolution structural and neurophysiological imaging to determine whether alterations in brain structure, function, or both contribute to HIV-related cognitive impairments. HIV-infected adults and individually matched controls completed 3-Tesla structural magnetic resonance imaging (sMRI) and a mechanoreception task during magnetoencephalography (MEG). MEG data were examined using advanced beamforming methods, and sMRI data were analyzed using the latest voxel-based morphometry methods with DARTEL. We found significantly reduced theta responses in the postcentral gyrus and increased alpha activity in the prefrontal cortices of HIV-infected patients compared with controls. Patients also had reduced gray matter volume in the postcentral gyrus, parahippocampal gyrus, and other regions. Importantly, reduced gray matter volume in the left postcentral gyrus was spatially coincident with abnormal MEG responses in HIV-infected patients. Finally, left prefrontal and postcentral gyrus activity was correlated with neuropsychological performance and, when used in conjunction, these two MEG findings had a sensitivity and specificity of over 87.5% for HIV-associated cognitive impairment. This study is the first to demonstrate abnormally increased activity in association cortices with simultaneously decreased activity in sensory areas. These MEG findings had excellent sensitivity and specificity for HIV-associated cognitive impairment, and may hold promise as a potential disease marker.

The Winograd Schema Challenge and Reasoning about Correlation

Abstract: The Winograd Schema Challenge is an alternative to the Turing Test that may provide a more meaningful measure of machine intelligence. It poses a set of coreference resolution problems that cannot be solved without human-like reasoning. In this paper, we take the view that the solution to such problems lies in establishing discourse coherence. Specifically, we examine two types of rhetorical relations that can be used to establish discourse coherence: positive and negative correlation. We introduce a framework for reasoning about correlation between sentences, and show how this framework can be used to justify solutions to some Winograd Schema problems.

Effect of paricalcitol on endothelial function and inflammation in type 2 diabetes and chronic kidney disease.

Abstract: Aims Patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD) have impaired endothelial function. Vitamin D and its analogs may play a role in regulation of endothelial function and inflammation. We studied effects of paricalcitol compared to placebo on endothelial function and markers of inflammation and oxidative stress in patients with T2DM and CKD.

Capital Inflows and Economic Growth: Does the Role of Institutions Matter?

Abstract: Recent evidence shows that institutions figure prominently in explaining the ‘Lucas paradox’. Using a threshold regression model, we extend this evidence to a situation where institutions index the relationship between foreign capital inflows and economic growth. We find strong and robust evidence that portfolio equity (including foreign direct investment) and debt inflows have positive effects on growth only in countries with high-quality institutions. Countries that fall below the threshold level of institutional quality record either insignificant or negative effects. This paper provides a possible explanation on the so-called Lucas paradox. Copyright © 2015 John Wiley & Sons, Ltd.

Coercion and social support behind bars testing an integrated theory of misconduct and resistance in U.S. prisons

Abstract: In this article, we examine key propositions from Colvin, Cullen, and Vander Ven's Differential Coercion/Social Support Theory (DCSST) to explain inmate violence, misconduct, and resistance within prison. RESULTS from logistic regression models applied to data from a sample of 481 prisoners incarcerated in state correctional facilities across the United States provide mixed support for the theory. Coercive experiences within prison are associated with engagement in violent misconduct as well as defiant and institutionalized forms of inmate resistance. However, social support is not consistently related to either misconduct or resistance. Furthermore, results suggest that prison staff can inhibit these reactive behaviors by effectively reducing violence and promoting safety within prisons. These findings have important implications for the status of DCSST and for advancing popular explanations of inmate misconduct. Language: en

Smoking accelerates pancreatic cancer progression by promoting differentiation of MDSCs and inducing HB-EGF expression in macrophages

Abstract: Smoking is an established risk factor for pancreatic cancer (PC), but late diagnosis limits the evaluation of its mechanistic role in the progression of PC. We used a well-established genetically engineered mouse model (LSL-K-ras(G12D)) of PC to elucidate the role of smoking during initiation and development of pancreatic intraepithelial neoplasia (PanIN). The 10-week-old floxed mice (K-ras(G12D); Pdx-1cre) and their control unfloxed (LSL-K-ras(G12D)) littermates were exposed to cigarette smoke (total suspended particles: 150 mg/m(3)) for 20 weeks. Smoke exposure significantly accelerated the development of PanIN lesions in the floxed mice, which correlated with tenfold increase in the expression of cytokeratin19. The systemic accumulation of myeloid-derived suppressor cells (MDSCs) decreased significantly in floxed mice compared with unfloxed controls (P<0.01) after the smoke exposure with the concurrent increase in the macrophage (P<0.05) and dendritic cell (DCs) (P<0.01) population. Further, smoking-induced inflammation (IFN-γ, CXCL2; P<0.05) was accompanied by enhanced activation of pancreatic stellate cells and elevated levels of serum retinoic acid-binding protein 4, indicating increased bioavailability of retinoic acid which contributes to differentiation of MDSCs to tumor-associated macrophages (TAMs) and DCs. TAMs predominantly contribute to the increased expression of heparin-binding epidermal growth factor-like growth factor (EGFR ligand) in pre-neoplastic lesions in smoke-exposed floxed mice that facilitate acinar-to-ductal metaplasia (ADM). Further, smoke exposure also resulted in partial suppression of the immune system early during PC progression. Overall, the present study provides a novel mechanism of smoking-induced increase in ADM in the presence of constitutively active K-ras mutation.

Intercultural Sensitivity through Short-Term Study Abroad.

Abstract: One of the foremost-cited rationales for study abroad during college is the development of a global perspective and intercultural sensitivity. Although this argument is mentioned frequently in promotional materials for study abroad, it has not yet been backed by research based on the outcomes of students’ study abroad experiences. As more students’ study abroad and study abroad programing becomes shorter, it is more important than ever to test the claims made by program organizers. The present mixed-methods study examined 12 students’ development in intercultural sensitivity over the period of a four-week study abroad program in Salamanca, Spain. Findings demonstrate that students made little changes in intercultural sensitivity as measured by the Intercultural Sensitivity Index and as reported in the qualitative data; however, these methods produced conflicting findings on students’ stages of intercultural sensitivity development.

Perceived stigma in persons with early-stage dementia: Longitudinal findings: Part 1.

Abstract: This longitudinal study examined perceived stigma in persons with dementia, with 50 persons with dementia, and 47 corresponding family caregivers. Data were collected at baseline and at 6, 12, and 18 months. Study results are reported in two parts, with findings regarding the stability of perceived stigma, measured using the modified Stigma Impact Scale, and relationship of stigma to person-centered variables being reported here. Findings included stability in perceived stigma, which did not show a downward trend until 18 months. Significant differences at baseline were found only for geographic location (rural vs. urban) with persons living in urban areas having higher levels of Stigma Impact Scale internalized shame compared to rural counterparts. Cognitive functioning was significantly, positively related to the Stigma Impact Scale social rejection and social isolation subscales. Findings support the enduring nature of perceived stigma over the early disease stages and the relationship of perceived stigma to some person-centered characteristics.