Physical Sciences and Mathematics Commons^™

Statistical Handling Of Medical Data - An Ethical Perspective, Ajay Kumar Bansal Dr

COBRA Preprint Series

Medical Science is a delicate subject and the clinical data generated from the medical trials must be reliable and of good quality. Not only the quality of generated data is important, but the management is also crucial and is to be handled very carefully. In this paper, the ethical aspect of statistical handling of such data is discussed.

Every profession has some set of norms to follow to achieve its objectives. These norms are called professional ethics which shows the essence of human behaviour. Same way, the field of medical research is expected to follow ethical norms, to obtain reliable …

Mapping Gravitational-Wave Backgrounds Of Arbitrary Polarisation Using Pulsar Timing Arrays, Jonathan Gair, Joseph D. Romano, Stephen R. Taylor

Physics and Astronomy Faculty Publications and Presentations

We extend our previous work on mapping gravitational-wave backgrounds using techniques borrowed from the analysis of cosmic microwave background data to backgrounds which have non-general-relativity (non-GR) polarisations. Our analysis and results are presented in the context of pulsar timing array observations, but the overarching methods are general, and can be easily applied to LIGO or eLISA observations using appropriately modified response functions. Analytic expressions for the pulsar timing response to gravitational waves with non-GR polarisation are given for each mode of a spin-weighted spherical-harmonic decomposition of the background, which permit the signal to be mapped across the sky to any …

Consequences Of Shifts In Abundance And Distribution Of American Chestnut For Restoration Of A Foundation Forest Tree, Harmony J. Dalgleish, Charles Dana Nelson, John A. Scrivani, Douglass F. Jacobs

Forestry and Natural Resources Faculty Publications

Restoration of foundation species, such as the American chestnut (Castanea dentata) that was devastated by an introduced fungus, can restore ecosystem function. Understanding both the current distribution as well as biogeographic patterns is important for restoration planning. We used United States Department of Agriculture Forest Service Forest Inventory and Analysis data to quantify the current density and distribution of C. dentata. We then review the literature concerning biogeographic patterns in C. dentata. Currently, 431 ± 30.2 million stems remain. The vast majority (360 ± 22 million) are sprouts < 2.5 cm dbh. Although this number is approximately 10% of the estimated pre-blight population, blight has caused a major shift in the size structure. The current-day population has a larger range, particularly west and north, likely due to human translocation. While climate change could facilitate northward expansion, limited seed reproduction makes this unlikely without assisted migration. Previous research demonstrates that the current, smaller population contains slightly higher genetic diversity than expected, although little information exists on biogeographic patterns in the genetics of adaptive traits. Our research provides a baseline characterization of the contemporary population of C. dentata, to enable monitoring stem densities …

Semi-Parametric Estimation And Inference For The Mean Outcome Of The Single Time-Point Intervention In A Causally Connected Population, Oleg Sofrygin, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

We study the framework for semi-parametric estimation and statistical inference for the sample average treatment-specific mean effects in observational settings where data are collected on a single network of connected units (e.g., in the presence of interference or spillover). Despite recent advances, many of the current statistical methods rely on estimation techniques that assume a particular parametric model for the outcome, even though some of the most important statistical assumptions required by these models are most likely violated in the observational network settings, often resulting in invalid and anti-conservative statistical inference. In this manuscript, we rely on the recent methodological …

Pre-Mission Input Requirements To Enable Successful Sample Collection By A Remote Field/Eva Team, Barbara A. Cohen, Darlene S. S. Lim, Kelsey E. Young, Anna Brunner, Richard C. Elphic, Audrey Horne, Mary C. Kerrigan, Gordon O. Osinski, John R. Skok, Steven W. Squyres, David Saint-Jacques, Jennifer L. Heldmann

Journal of Human Performance in Extreme Environments

We used a field excursion to the West Clearwater Lake Impact structure as an opportunity to test factors that contribute to the decisions a remote field team (for example, astronauts conducting extravehicular activities (EVA) on planetary surfaces) makes while collecting samples for return to Earth. We found that detailed background on the analytical purpose of the samples, provided to the field team, enables them to identify and collect samples that meet specific analytical objectives. However, such samples are not always identifiable during field reconnaissance activities, and may only be recognized after outcrop characterization and interpretation by crew and/or science team …

Long-Term Landscape Changes In A Subalpine Spruce-Fir Forest In Central Utah, Usa, Jesse L. Morris, R. Justin Derose, Andrea R. Brunelle

Wildland Resources Faculty Publications

Background: In Western North America, increasing wildfire and outbreaks of native bark beetles have been mediated by warming climate conditions. Bioclimatic models forecast the loss of key high elevation species throughout the region. This study uses retrospective vegetation and fire history data to reconstruct the drivers of past disturbance and environmental change. Understanding the relationship among climate, antecedent disturbances, and the legacy effects of settlement-era logging can help identify the patterns and processes that create landscapes susceptible to bark beetle epidemics. Methods: Our analysis uses data from lake sediment cores, stand inventories, and historical records. Sediment cores were dated with …

Operational Exploitation Of Satellite-Based Sounding Data And Numerical Weather Prediction Models For Directed Energy Applications, David C. Meier

Theses and Dissertations

The wealth of available scientific data collected by the modern constellation of meteorological satellites can be exploited in new and innovative ways, with direct benefit to directed energy applications. The Atmospheric Infrared Sounder (AIRS) provides accurate, geolocated temperature data, which are used as the starting point for the derivation of atmospheric parameters critical to prediction of sensor or directed energy system performance. Twenty-four hour data coverage is achieved by extending the atmospheric characterization between satellite observations using Numerical Weather Prediction (NWP) models. A technique is developed to derive wind profiles using AIRS temperature data and the accuracy of these winds …

Geometric Auxetics, Ciprian Borcea, Ileana Streinu

Computer Science: Faculty Publications

We formulate a mathematical theory of auxetic behavior based on one-parameter deformations of periodic frameworks. Our approach is purely geometric, relies on the evolution of the periodicity lattice and works in any dimension. We demonstrate its usefulness by predicting or recognizing, without experiment, computer simulations or numerical approximations, the auxetic capabilities of several well-known structures available in the literature. We propose new principles of auxetic design and rely on the stronger notion of expansive behavior to provide an infinite supply of planar auxetic mechanisms and several new three-dimensional structures.

Photonic Topological Chern Insulators Based On Tellegen Metacrystals, Daniel A. Jacobs, Andrey E. Miroshnichenko, Yuri S. Kivshar, Alexander B. Khanikaev

Publications and Research

We demonstrate that topologically nontrivial states of light can be engineered in periodic photonic structures containing media with a Tellegen-type bianisotropic response. Whilst in such bianisotropic materials the time-reversal symmetry is broken, they are characterized by an intrinsic magnetic order which does not require macroscopic magnetization. Our design can therefore be considered as a direct analog of the solid state Chern insulator which exhibits a topological order in the absence of an external bias. Numerical simulations of such Tellegen photonic crystals reveal the existence of one way edge transport at domain walls and perfectly conducting boundaries not sensitive to structural …

Statistical Estimation Of White Matter Microstructure From Conventional Mri, Leah Suttner, Amanda Mejia, Blake Dewey, Pascal Sati, Daniel S. Reich, Russell T. Shinohara

UPenn Biostatistics Working Papers

Diffusion tensor imaging (DTI) has become the predominant modality for studying white matter integrity in multiple sclerosis (MS) and other neurological disorders. Unfortunately, the use of DTI-based biomarkers in large multi-center studies is hindered by systematic biases that confound the study of disease-related changes. Furthermore, the site-to-site variability in multi-center studies is significantly higher for DTI than that for conventional MRI-based markers. In our study, we apply the Quantitative MR Estimation Employing Normalization (QuEEN) model to estimate the four DTI measures: MD, FA, RD, and AD. QuEEN uses a voxel-wise generalized additive regression model to relate the normalized intensities of …

Unique Pseudo-Expectations For C∗-Inclusions, David R. Pitts, Vrej Zarikian

Department of Mathematics: Faculty Publications

Given an inclusion D⊆C of unital C ∗ -algebras (with common unit), a unital completely positive linear map Φ of C into the injective envelope I(D) of D which extends the inclusion of D into I(D) is a pseudo-expectation. Pseudo-expectations are generalizations of conditional expectations, but with the advantage that they always exist. The set PsExp(C,D) of all pseudo-expectations is a convex set, and when D is Abelian, we prove a Krein–Milman type theorem showing that PsExp(C,D) can be recovered from its set of extreme points. In general, PsExp(C,D) is not a singleton. However, there are large and natural classes …

Fast And Accurate Evaluation Of Lifepo4 Cathode Materials By Single Particle Microelectrode, Fu-Qing Wang, Yi-Min Wei, Yu-Zhuan Su, Bing-Wei Mao, Kai Wu, Feng-Gang Zhao, Chun-Lei Chen, Xing-Lu Li, Jin Chong

Journal of Electrochemistry

Single particle microelectrode enables to evaluate the electrochemical responses for single particle of active material without binder and conductive agent. Thus, the influences of additive and electrode structure on the electrochemical performance of active materials can be ignored. Furthermore, this technology can be used to evaluate active materials fast. Therefore, single particle microelectrode allows fast and accurate determination of the intrinsic performance of active material. Cyclic voltammogram (CV), cycle performance, and kinetic behavior of LiFePO4 cathode materials were evaluated by the single particle microelectrode. CV curve of LiFePO4 particle with a pair of oxidation and reduction peaks was obtained with …

Electrodeposition Of Lanthanum In Deep Eutectic Solvents, Li Wang, You-Jun Fan, Lu Wei, Hai-Xia Liu, Shi-Gang Sun

Journal of Electrochemistry

With the choline chloride/urea deep eutectic solvents (DESs) as the medium, the olive-like lanthanum particles with uniform shape and size were successfully prepared through a potentiostatic deposition method. The prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). At the same time, the effect of deposition potential, temperature and time on the size and morphology of samples was investigated. The results demonstrated that the optimum conditions for the preparation of olive-like lanthanum particles were as follows: deposition potential of -1.7 V, temperature of 80 ^oC …

Effect Of Mno2 Content On Electrochemical Capacitance Behavior Of Active Carbon Electrode, Kun Shen, Xian-Liang Zhou, Qi-Shun Duan

Journal of Electrochemistry

In this work, the manganese dioxide (MnO₂) materials were prepared by solution approach at low temperature, thermal decomposition and electrochemical deposition. The actived carbon (AC) and MnO₂ composite electrodes were used for aqueous supercapacitors. The morphologies and structures of the prepared materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the electrochemical behaviors were tested by cyclic voltammetry (CV) and galanostatic charge-discharge tests. Electrochemical test data show that the maximum specific capacitances of 151, 172 and 141 F•g^-1 were obtained with the contents of MnO₂ being 70, 60 and 70% in …

The Varieties Of Indispensability Arguments, Marco Panza, Andrea Sereni

MPP Published Research

The indispensability argument (IA) comes in many different versions that all reduce to a general valid schema. Providing a sound IA amounts to providing a full interpretation of the schema according to which all its premises are true. Hence, arguing whether IA is sound results in wondering whether the schema admits such an interpretation. We discuss in full details all the parameters on which the specification of the general schema may depend. In doing this, we consider how different versions of IA can be obtained, also through different specifications of the notion of indispensability. We then distinguish between schematic and …

Special Issue: Electrochemistry Of Carbon Materials, Chen Wei

Journal of Electrochemistry

Carbon materials are traditional electrode materials due to their excellent electrical conductivities, high electrochemical stabilities and wide potential windows. Glassy carbon, graphite, various activated charcoals, carbon fibers etc. have been widely used in electrochemistry serving as electrode substrates or supports. In addition to their applications in basic electrochemistry, carbon materials have also played important roles in electrochemical energy storage and conversion. In recent years, various types of carbon structures, from zero-dimensional carbon nanodots, one-dimensional nanotubes, two-dimensional graphene to three-dimensional porous carbons, have attracted increasing attention in electrochemical field. It has been found that carbon materials have outstanding properties as advanced …

Colloidal Ionic Supercapacitors, Kun-Feng Chen, Dong-Feng Xue

Journal of Electrochemistry

Supercapacitors have high power density and long cycle life compared with battery systems, but they still suffer from low energy density at the same time. In order to increase the energy density of supercapacitors, we have developed a new type of pseudocapacitor, called colloidal ion supercapacitor, which can directly use commercial metal salts as electrode materials and form electroactive matter by in-situ electrochemical reactions without the need of additional materials synthesis processes. Colloidal ion supercapacitor can fully utilize the redox reaction of metal cations with multiple oxidation states, which can completely release the stored electrical energy of multiple-valence cations, leading …

Electrochemical Properties Of Graphene/Porous Nano-Silicon Anode, Chun-Li Li, Guang Yang, Ping Zhang, Zhi-Yu Jiang

Journal of Electrochemistry

Porous nano-silicon (Si) was prepared by acid etching Al-Si alloy powder method, and used as an active material for fabricating a grapene/porous nano-Si electrode. The results of SEM and TEM measurements indicated that porous nano-Si powder was uniformly mixed with graphene by emulsification dispersion-ultrasonication method. As an anode for lithium ion battery, the graphene/porous nano-Si electrode presented relatively high performance in 1 mol•L^-1 LiPF6/EC:DMC = 1:1(by volume) + 1.5% (by mass) VC solution. At the charge and discharge current densities of 0.5A•g^-1, the first discharge capacity was 1768.6 mAh•g^-1 with coulombic efficiency of 68.3%. The discharge …

Applications Of Carbon Materials In Electrochemical Energy Storage, Ji Liang, Lei Wen, Hui-Ming Cheng, Feng Li

Journal of Electrochemistry

An electrode material for electrochemical energy storage is one of the key components for high performance devices. In a variety of electrochemical energy storage systems, carbon materials, especially the lately emerged carbon nanomaterials including the carbon nanotube and graphene, have been playing a very important role and brought new vitality to the development and demonstration of the broad application prospects. In this review, we summarize the applications of various carbon materials in the typical electrochemical energy storage devices, namely lithium/sodium ion batteries, supercapacitors, and lithium-sulfur batteries, as well as flexible electrochemical energy storage and electrochemical catalysis. A perspective of novel …

Progress Of Self-Supported Supercapacitor Electrode Materials Based On Carbon Substrates, Shui-Jian He, Wei Chen

Journal of Electrochemistry

Self-supported electrode materials have been widely used in supercapacitors. Carbon materials are promising substrates in building self-supported electrode materials attributed to their diverse structures, rich resource, relatively low cost and high stability. Combined with our own research in this field, we summarize here the recent progress on the synthesis of self-supported electrode materials and their supercapacitance properties. The overall synthetic strategy could be divided into two categories: “top-down” and “bottom-up”. We hope this review is helpful for the development and application of renewable sources in self-supported electrode materials.

Synthesis Of Porous Carbon Nanosheets And Its Application In Sodium-Ion Battery, Jing-Fei Zhang, Jing Lu, Xiao-Yu Yang, Yun-Di Huang, Lin Xu, Dong-Mei Sun, Ya-Wen Tang

Journal of Electrochemistry

Owning to sodium’s high abundance, relatively low cost, similar chemical properties to Li and very suitable redox potential of E0(Na+/Na) = -2.71 V versus SHE which is only 0.3 V above that of lithium, rechargeable sodium ion battery hold much promise as potential alternatives to current lithium ion batteries for energy storage applications. Carbon material is regarded as the most promising anode candidate for sodium ion battery. Particularly, carbon nanosheet with porous structure and high conductivity is expected to have improved sodium ion storage properties. In this paper, we present a two-step pyrolysis-based method for facile synthesis of porous carbon …

Carbon Aerogel/Nickel Foam As Electrode For High-Performance Supercapacitor, Zhong Wu, Xin-Bo Zhang

Journal of Electrochemistry

Herein, a facile synthesis has been explored to prepare carbon aerogel/Ni foam. Graphene oxide, resorcinol and formaldehyde serve as precursors and polymerize in-situ on the Ni foam after hydrothermal synthesis at 85 oC. After lyophilization treatment, the carbon aerogel/Ni foam with porous structure can be obtained. Electrochemical investigations reveal that the carbon aerogel/Ni foam exhibits superior performances in both aqueous and organic electrolytes involving high specific capacitance and long-term cycling stability. The excellent properties can be ascribed to the unique formation and porous structure, which allows more effective transportations of electron and electrolyte ion.

Intercalation Of Clo4- Into Hopg Investigated By Ec-Stm, Xiao-Yan Hu, Alice Aliwowe, Jia-Wei Yan, Bing-Wei Mao

Journal of Electrochemistry

The electrochemical intercalation and surface morphology of highly oriented pyrolytic graphite (HOPG) electrode in 2 mol•L^-1 HClO₄ were studied by in situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV). Based on the step-height changes observed before and after the intercalation, the effects of different step sites on intercalation are compared. The feasibility, reversibility and speed of intercalation are discussed. The intercalation of ClO₄^- into HOPG can be divided into three types depending on the number of graphite layers at the step site: When the layers of graphite are more than three, the intercalation becomes feasible; …

U.S. Drought Monitor, December 22, 2015, Richard R. Heim Jr.

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 22, 2015 (12/22/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Evolutionary Dynamics Of Speciation And Extinction, Dawn Michelle King

Dissertations

Presented here is an interdisciplinary study that draws connections between the fields of physics, mathematics, and evolutionary biology. Importantly, as we move through the Anthropocene Epoch, where human-driven climate change threatens biodiversity, understanding how an evolving population responds to extinction stress could be key to saving endangered ecosystems. With a neutral, agent-based model that incorporates the main principles of Darwinian evolution, such as heritability, variability, and competition, the dynamics of speciation and extinction is investigated. The simulated organisms evolve according to the reaction-diffusion rules of the 2D directed percolation universality class. Offspring are generated according to one of three reproduction …

Nonparametric Methods For Data In Infinite Dimensional Space., Anirvan Chakraborty Dr.

Doctoral Theses

For univariate as well as finite dimensional multivariate data, there is an extensive literature on nonparametric statistical methods. One of the reasons for the popularity of nonparametric methods is that it is often difficult to justify the assumptions (e.g., Gaussian distribution of the data) made in the models used in parametric methods. Nonparametric procedures use more flexible models, which involve less assumptions. So, they are more robust against possible departures from the model assumptions, and are applicable to a wide variety of data. Nonparametric methods outperform their parametric competitors in many situations, where the assumptions required for the parametric methods …

Reliability And Validity Of Neurobehavioral Function On The Psychology Experimental Building Language Test Battery In Young Adults, Brian J. Piper, Shane Mueller, Alexander R. Geerken, Kyle L. Dixon, Gregory Kroliczak, Reid H. Olsen, Jeremy K. Miller

Michigan Tech Publications

Background. The Psychology Experiment Building Language (PEBL) software consists of over one-hundred computerized tests based on classic and novel cognitive neuropsychology and behavioral neurology measures. Although the PEBL tests are becoming more widely utilized, there is currently very limited information about the psychometric properties of these measures.

Methods. Study I examined inter-relationships among nine PEBL tests including indices of motor-function (Pursuit Rotor and Dexterity), attention (Test of Attentional Vigilance and Time-Wall), working memory (Digit Span Forward), and executive-function (PEBL Trail Making Test, Berg/Wisconsin Card Sorting Test, Iowa Gambling Test, and Mental Rotation) in a normative sample (N = 189, …

Evaluating Different Distributed-Cyber-Infrastructure For Data And Compute Intensive Scientific Application, Arghya Kusum Das, Seung Jong Park, Jaeki Hong, Wooseok Chang

Computer Science Faculty Research & Creative Works

Scientists are increasingly using the current state of the art big data analytic software (e.g., Hadoop, Giraph, etc.) for their data-intensive applications over HPC environment. However, understanding and designing the hardware environment that these data- and compute-intensive applications require for good performance is challenging. With this motivation, we evaluated the performance of big data software over three different distributed-cyber-infrastructures, including a traditional HPC-cluster called SuperMikeII, a regular datacenter called SwatIII, and a novel MicroBrick-based hyperscale system called CeresII, using our own benchmark Parallel Genome Assembler (PGA). PGA is developed atop Hadoop and Giraph and serves as a good real-world example …

Vascular Tree Structure: Fast Curvature Regularization And Validation, Egor Chesakov

Electronic Thesis and Dissertation Repository

This work addresses the challenging problem of accurate vessel structure analysis in high resolution 3D biomedical images. Typical segmentation methods fail on recent micro-CT data sets resolving near-capillary vessels due to limitations of standard first-order regularization models. While regularization is needed to address noise and partial volume issues in the data, we argue that extraction of thin tubular structures requires higher-order curvature-based regularization. There are no standard segmentation methods regularizing surface curvature in 3D that could be applied to large 3D volumes. However, we observe that standard measures for vessels structure are more concerned with topology, bifurcation angles, and other …

Apparent Glacially Induced Structural Controls On Limestone Conduit Development In Ohio Caverns, United States, Adrienne M. Watts, Ira D. Sasowsky

International Journal of Speleology

Rock discontinuities such as bedding planes and joints are important controls on the form that caves take. We examined structural controls on the development of Ohio Caverns. The cave formed in Devonian limestone underlying a small bedrock knob (Mt. Tabor) within the Interior Lowland province, United States. The area has been overridden by continental glaciation multiple times. The bedrock is pervasively fractured, with many curved and wavy near-vertical fractures showing many different orientations. In the case of Ohio Caverns, it appears that the controlling fractures in map view may not be joints sensu stricto, but rather some combination of …