University of Nebraska Omaha

About: University of Nebraska Omaha is a education organization based out in Omaha, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 4526 authors who have published 8905 publications receiving 213914 citations. The organization is also known as: UNO & University of Omaha.

A Novel Approach to Measure Variability in the Anterior Cruciate Ligament Deficient Knee During Walking: The Use of the Approximate Entropy in Orthopaedics

Abstract: Objective. The evaluation of variability of biological rhythmic activities through measures such as Approximate Entropy (ApEn) has provided important information regarding pathology in disciplines such as cardiology and neurology. This research lead to the “loss of complexity hypothesis” where decreased variability is associated with loss of healthy flexibility rendering the system more rigid and unable to adapt to stresses. ApEn as a measure of variability and complexity, correlates well with pathology while, in some cases, it is predictive of subsequent clinical changes. The study of human gait could benefit from the application of ApEn since it is also a rhythmical oscillation. Our aim was to assess the variability of the ACL deficient knee, since ACL rupture is a common musculoskeletal injury and is accompanied by altered gait patterns and future pathology in the joint. We hypothesized that the ACL deficient knee will exhibit more regular and less variable walking patterns than the contralateral intact knee. Methods. Ten subjects with unilateral deficiency walked on a treadmill at their self-selected speed, 20% faster, and 20% slower, while kinematics were collected (50 Hz) from 80 consecutive strides for each condition. The ApEn of the resulted knee joint flexion-extension time series was calculated. Results. Significantly smaller ApEn values were found in the ACL deficient knee when compared with the contralateral intact (F = 5.57, p = 0.022), for all speeds. ApEn values significantly increased (F = 5.79, p = 0.005) with increases in walking speed. Conclusions. The altered properties of the ACL deficient knee, which exhibits more regular and less variable patterns than the contralateral intact knee, may decrease the adaptability of the system rendering it less able to adjust to perturbations. This could explain the increased future pathology found in the deficient knee. ApEn can be an important tool in assessing pathology and therapeutic interventions in orthopaedics.

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.

Shotgun proteomic analysis of human-induced sputum.

Abstract: Induced sputum is a readily accessible biological fluid whose composition may alter as a consequence of disease. To date, however, the proteins that routinely populate this biofluid are largely unknown, in part due to the technical difficulties in processing such mucin-rich samples. To provide a catalogue of sputum proteins, we have surveyed the proteome of human-induced sputum (sputome). A combination of 2-D gel analysis and GeLC-MS/MS allowed a total of 191 human proteins to be confidently assigned. In addition to the expected components, several hitherto unreported proteins were found to be present, including three members of the annexin family, kallikreins 1 and 11, and peroxiredoxins 1, 2 and 5. Other sets of proteins identified included four proteins previously annotated as hypothetical or conserved hypothetical. Taken together, these data represent the first extensive survey of the proteome of induced sputum and provide a platform for future identification of biomarkers of lung disease.