Quantifying Performance of Bipedal Standing with Multi-channel EMG

Spinal cord stimulation has enabled humans with motor complete spinal cord injury (SCI) to independently stand and recover some lost autonomic function. Quantifying the quality of bipedal standing under spinal stimulation is important for spinal rehabilitation therapies and for new strategies that seek to combine spinal stimulation and rehabilitative robots (such as exoskeletons) in real time feedback. To study the potential for automated electromyography (EMG) analysis in SCI, we evaluated the standing quality of paralyzed patients undergoing electrical spinal cord stimulation using both video and multi-channel surface EMG recordings during spinal stimulation therapy sessions. The quality of standing under different stimulation settings was quantified manually by experienced clinicians. By correlating features of the recorded EMG activity with the expert evaluations, we show that multi-channel EMG recording can provide accurate, fast, and robust estimation for the quality of bipedal standing in spinally stimulated SCI patients. Moreover, our analysis shows that the total number of EMG channels needed to effectively predict standing quality can be reduced while maintaining high estimation accuracy, which provides more flexibility for rehabilitation robotic systems to incorporate EMG recordings

Algebraic analysis of Trivium-like ciphers

Trivium is a bit-based stream cipher in the final portfolio of the eSTREAM project. In this paper, we apply the approach of Berbain et al. to Trivium-like ciphers and perform new algebraic analyses on them, namely Trivium and its reduced versions: Trivium-N, Bivium-A and Bivium-B. In doing so, we answer an open question in the literature. We demonstrate a new algebraic attack on Bivium-A. This attack requires less time and memory than previous techniques which use the F4 algorithm to recover Bivium-A's initial state. Though our attacks on Bivium-B, Trivium and Trivium-N are worse than exhaustive keysearch, the systems of equations which are constructed are smaller and less complex compared to previous algebraic analysis. Factors which can affect the complexity of our attack on Trivium-like ciphers are discussed in detail

Social Psychological Analysis of the Women's Movement

Sociolog

Visualization of the small RNA transcriptome using seqclusterViz

The study of small RNAs provides us with a deeper understanding of the complexity of gene regulation within cells. Of the different types of small RNAs, the most important in mammals are miRNA, tRNA fragments and piRNAs. Using small RNA-seq analysis, we can study all small RNA types simultaneously, with the potential to detect novel small RNA types. We describe SeqclusterViz, an interactive HTML-javascript webpage for visualizing small noncoding RNAs (small RNAs) detected by Seqcluster. The SeqclusterViz tool allows users to visualize known and novel small RNA types in model or non-model organisms, and to select small RNA candidates for further validation. SeqclusterViz is divided into three panels: i) query-ready tables showing detected small RNA clusters and their genomic locations, ii) the expression profile over the precursor for all the samples together with RNA secondary structures, and iii) the mostly highly expressed sequences. Here, we show the capabilities of the visualization tool and its validation using human brain samples from patients with Parkinson's disease

Essays in International Economics and Macroeconomics

The first chapter presents a study on the employment effects of periodic policy lapses and renewals. Economic theory postulates that uncertainty and temporary disruptions in policies could lead to more permanent effects on the real economy by reducing growth and investment. The sources of policy uncertainty are manifold (Baker et al., 2014), in which political polarization is a potential explanation in the rise in policy-related economic uncertainty in the U.S.. One way in which political polarization could translate to greater policy uncertainty is the challenges involved in passing policies that are subjected to periodic lapses and retroactive renewal. This paper seeks to examine the cost of this type of policy shock on firm employment outcomes. I utilized the periodic lapses and renewals of the Generalized Systems of Preferences (GSP) in the 1990s to estimate the effects on firm employment. Depending on the amount of imports, firms with higher dependency on the GSP regime experienced slower employment growth. The difference in the employment growth rates between the GSP firms and controls persists for about four years. The second chapter discusses a key empirical challenge in measuring misallocation and proposes a method to resolve the identification problem. The challenge in the misallocation literature made popular by Hsieh and Klenow (2009) is the identification of model parameters: a standard implementation cannot separately identify the production function parameters from the measures of distortion. In this paper, my co-author and I formally characterize two biases related to this lack of identification: mismeasuring the labor output elasticity in a constant returns-to-scale world, and assuming constant returns to scale when returns to scale in production are not constant. In both cases, the econometrician’s error induces spurious correlations between productivity and distortions, leading the econometrician to mismeasure misallocation. We first show how misallocation measures in this class of models can be identified even when we cannot identify all the model parameters. We then use U.S. Census Bureau microdata and document the magnitude of the two biases. The third chapter measures the aggregate employment growth and reallocation effects of multinational firms in the U.S. over the past decade and across the manufacturing, retail, wholesale, and service sectors. At a fundamental level, understanding the contribution of multinational firms to U.S. employment growth in contrast to non-multinational firms is the first-order issue. Are MNCs a major component of U.S. manufacturing employment decline? Did they grow faster relative to their domestic counterparts? Did they create and destroy more jobs at new and existing establishments relative to controls? And, given that MNCs are often vertically integrated and operate multiple lines of business, in what sectors did they create and destroy jobs? My co-authors and I exploit a novel combination of two micro datasets: the restricted-use U.S. Census Bureau establishment-level microdata and the Bureau van Dyke Orbis firm database. The combined dataset links firm and establishment-level activity to the scope and extent of a firm’s global operations. We find that MNCs recorded higher total employment growth rates relative to the comparison group of non-MNCs. Furthermore, MNCs create more and destroy fewer jobs than non-MNCs. Moreover, MNCs are found to have created relatively more jobs across all sectors; notably in the services sector. This result suggests that within-firm reallocation across sectors may be increasingly important in the study of business dynamism.PHDEconomicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/138448/1/sjadeho_1.pd

The diurnal cycle of precipitation over the maritime continent in a high-resolution atmospheric model

Climate models can exhibit systematic errors in their mean precipitation over the Maritime Continent of the Indonesian archipelago at the heart of the tropical warm pool. These can often be traced back to an erroneous simulation of the diurnal cycle, and can lead to errors in global climate, through planetary wave propagation. Here, we examine the simulation of the diurnal cycle over the Maritime Continent in a series of high-resolution integrations of the UK Met Office atmospheric model, with horizontal resolutions of 40 and 12 km (where the convection is parametrised) and 4 km (where the convection is explicitly resolved), as part of the Cascade project. In these models, the vertical heating profile over the islands changes from a convective profile with a mid-tropospheric maximum in the early afternoon to a more stratiform profile with upper-tropospheric heating and mid-tropospheric cooling later. The convective heating profile forces a first internal mode gravity wave that propagates rapidly offshore; the deep warm anomalies behind its downwelling wavefront suppress convection offshore during early afternoon. The stratiform heating profile forces a gravity wave with a higher-order vertical mode that propagates slowly offshore later in the afternoon. This mode has a negative, destabilising temperature anomaly in the mid-troposphere. Together with the convergence zone between the wave fronts of the two modes, favourable conditions are created for offshore convection. In the 4 km explicit convection model, the offshore convection responds strongly to this gravity wave forcing, in agreement with observations, supporting a gravity wave–convection paradigm for the diurnal cycle over the Maritime Continent. However, the convective response in the lower-resolution models is much less coherent, leading to errors in the diurnal cycle and mean precipitation. Hence, to improve climate model simulations, sensitivity to gravity wave forcing should be a factor in future convective parametrisation schemes

Parametric modeling of cellular state transitions as measured with flow cytometry

<p>Abstract</p> <p>Background</p> <p>Gradual or sudden transitions among different states as exhibited by cell populations in a biological sample under particular conditions or stimuli can be detected and profiled by flow cytometric time course data. Often such temporal profiles contain features due to transient states that present unique modeling challenges. These could range from asymmetric non-Gaussian distributions to outliers and tail subpopulations, which need to be modeled with precision and rigor.</p> <p>Results</p> <p>To ensure precision and rigor, we propose a parametric modeling framework StateProfiler based on finite mixtures of skew <it>t</it>-Normal distributions that are robust against non-Gaussian features caused by asymmetry and outliers in data. Further, we present in StateProfiler a new greedy EM algorithm for fast and optimal model selection. The parsimonious approach of our greedy algorithm allows us to detect the genuine dynamic variation in the key features as and when they appear in time course data. We also present a procedure to construct a well-fitted profile by merging any redundant model components in a way that minimizes change in entropy of the resulting model. This allows precise profiling of unusually shaped distributions and less well-separated features that may appear due to cellular heterogeneity even within clonal populations.</p> <p>Conclusions</p> <p>By modeling flow cytometric data measured over time course and marker space with StateProfiler, specific parametric characteristics of cellular states can be identified. The parameters are then tested statistically for learning global and local patterns of spatio-temporal change. We applied StateProfiler to identify the temporal features of yeast cell cycle progression based on knockout of S-phase triggering cyclins Clb5 and Clb6, and then compared the S-phase delay phenotypes due to differential regulation of the two cyclins. We also used StateProfiler to construct the temporal profile of clonal divergence underlying lineage selection in mammalian hematopoietic progenitor cells.</p

Education inequality: become better or worse?

Inequality measured by using Theil index, can be decomposed into between and within–groups. Normally, studies only focus on the inequality within-group due to high percentage of inequality within-group as compared to the between-group. Therefore, the conclusions that have been made in the past have neglected the between-group inequality. In this study, education achievement is used as indicator, and between-group inequality is observed for the case study in Sabah, Malaysia. It is noted that while the education inequality in urban and rural areas as well as its overall level has decreased, the gap between two areas has become more distinct