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Coupled Eulerian–Lagrangian Extended Finite Element Approach To Simulating The Mechanics And Growth Of Biofilm, Cells, And Tissues, Ravindra Duddu, Anup Aryal, Louis Foucard, Franck Vernerey

Society of Engineering Science 51st Annual Technical Meeting Archive

Simulating the mechanics and growth of soft biological and biomimetic materials (e.g., hydrogels, fibroblast-ECM system, biofilm evolution, cell protrusion, spreading of a cell nucleus) requires coupling large deformation solid mechanics with fluid mechanics, advective-diffusive transport, growth, and the evolution of embedded phase/material interfaces. The standard Lagrangian finite element approach suffers from numerical issues due to excessive mesh distortion and mesh-moving/remeshing algorithms can be cumbersome; therefore, there is a need for more robust and efficient numerical approaches. An Eulerian finite element approach that allows the material to move against the numerical mesh does not suffer from mesh distortion issues; so, it …

Compression Of Fibrin Networks Modeled As A Foam, Prashant Purohit

Society of Engineering Science 51st Annual Technical Meeting Archive

Fibrin networks are important components of extracellular proteinaceous gels that are widely used in biological experiments as well as medical applications. They are also the key components of blood clots. Although the tensile and shear behavior of these gels is relatively well-understood, the compression response is not. We show here that the compression behavior of fibrin networks is very similar to the compression response of cellular solids. There is an initial linear regime in which most fibers are straight. This is followed by a plateau regime in which more and more fibers buckle, whereas the stress remains nearly constant as …

Computational Modeling Of Biomechanics: Biological Growth And Morphogenesis, Jiaoyan Li, Lijie Zhang, James Lee

Society of Engineering Science 51st Annual Technical Meeting Archive

Unlike common engineering materials, living matter can autonomously respond to environmental changes to become stronger, weaker, larger, or smaller within months, weeks, days, or even seconds as a result of a continuous microstructural renewal and adaption. The importance of mechanics in developmental biology is well established, where biomechanical forces and constraints are the bridge that connects genetic and molecular-level events to tissue-level deformations that shape the developing embryo. Moreover, feedback from the mechanical environment affects gene expression and differentiation. Therefore, mechanical forces and constraints are not only a proximal cause of biological growth and morphogenesis, but also play a regulatory …

Numerical And Experimental Investigations On Biomimetic -Material: Stomatopod Dactyl Club, Nobphadon Suksangpanya

Society of Engineering Science 51st Annual Technical Meeting Archive

The smashing stomatopod, Odontodactylus scyllarus, has been known for its heavily smashing blow creating the velocity and acceleration equivalent to a 0.22 caliber bullet with the forces up to 1.5 kN and the load-bearing part of its raptorial appendages, so-called dactyl club, having a capability of withstanding such tremendous forces. The focus of this research is on this extraordinary damage tolerant dactyl club. The dactyl club is mainly characterized by mineralized fiber layers resembled as a helicoidal arrangement. In this study, the helicoidal composite is the design of biomimetic material and is fabricated by 3D-printing prototype and glass fiber–epoxy composites. …

Unveiling The Resistance To Penetration Of The Radular Teeth Of The Cryptochiton Stelleri, Enrique Escobar De Obaldia, Chanhue Jeong, Pablo Zavattieri, Lessa Kay Grunenfelder, Steven Herrera, David Kisailus

Society of Engineering Science 51st Annual Technical Meeting Archive

The tongue of the C. stelleri is provided with numerous rows of highly mineralized teeth composed of a soft organic chitin matrix and hard magnetite rods. The shell of the tooth is characterized with the highest modulus and hardness of any known biomineral. Similar to other biological materials (i.e., nacre and conch), the tooth is provided with mineral bridges, nanoscale asperities and roughness, and a microstructure composed of stiff piled rods wrapped in a matrix of soft organic material. Despite the advanced microscopic techniques used today, not much has been said about the influence of the geometrical aspects in the …

Toughening Mechanisms In Bioinspired Multilayered Materials, Sina Askarinejad, Nima Rahbar

Society of Engineering Science 51st Annual Technical Meeting Archive

Outstanding mechanical properties of biological multilayered materials are strongly influenced by nanoscale features in their structure. In this study, mechanical behavior and toughening mechanisms of abalone nacre-inspired multilayered materials are explored. In nacre’s structure, the organic matrix, pillars and the roughness of the -aragonite platelets play important roles in its overall mechanical performance. A micromechanics model for multilayered biological materials is proposed to simulate their mechanical deformation and toughening mechanisms. The fundamental hypothesis of the model is that nanoscale pillars and asperities have near theoretical strength. It has been shown earlier that organic matrix behaves stiffer in proximity of mineral …

Strain Rate Hardening In Biological And Biomimetic Composites: A Critical Ingredient To Mechanical Performance?, Francois Barthelat, Ravi Chintapalli, Ahmad Dastjerdi, Stephanie Breton

Society of Engineering Science 51st Annual Technical Meeting Archive

Natural materials such as nacre, bone, collagen, or spider silk boast unusual combinations of stiffness, strength, and toughness. Behind this performance is the staggered microstructure, which consists of stiff and elongated inclusions embedded in a softer and more deformable matrix. The micromechanics of deformation and failure associated with this microstructure are now well understood at the “unit cell” level, the smallest representative volume for this type of material. However, these mechanisms only translate to high performance if they propagate throughout large volumes, an important condition which is often overlooked. Here we present, for the first time, a model which captures …

Computational Modeling Of Cell–Cell Interaction And Multicell Migration, Xiaowei Zeng

Society of Engineering Science 51st Annual Technical Meeting Archive

Cell migration plays an essential role in many physiological processes including morphogenesis, wound healing, and tumor metastases. To accomplish certain physiological tasks, cell motion must occur in a defined direction. The failure of cells to migrate or migration to inappropriate locations can result in abnormities and diseases, such as tumor formation and metastasis. To explain such biological and biophysical phenomenon has been the focus of cell research as well as cell mechanics research. In this presentation, we shall present our latest results on modeling and simulation of cell-cell interaction and cell migration. The macroscale cell is modeled as soft materials …

Nanomechanics Based Investigation Into Interface -Thermomechanics Of Collagen And Chitin Based Biomaterials, Tao Qu, Vikas Tomar

Society of Engineering Science 51st Annual Technical Meeting Archive

From the biological/chemical perspective, interface concepts related to cell surface/synthetic biomaterial interface and extracellular matrix/biomolecule interface have wide applications in medical and biological technology. Some findings regarding interfaces controlling biological reactions are like surfaces provide high accessibility for reaction, high surface area geometries that can be created to enhance reaction turnover rates, unique organic microenvironments that can enhance specific affinities and reactions, self-assembly in the plane of the interface that can be used to orient and space molecules with precision, and surface energy minimization can orient specific structures to interfaces. The focus of the presented work is on investigating thermal …

In-Situ Stress Measurement During Aluminum Corrosion In Alkaline Solutions, Ömer Özgür Çapraz, Shinsuke Ide, Kurt R. Hebert, Pranav Shrotriya

Society of Engineering Science 51st Annual Technical Meeting Archive

Stress Corrosion Cracking is the mechanical degradation of metal in corrosive environment and it is characterized by crack growth during corrosion of metals in the presence of external stress. The synergism of corrosion and mechanical degradation in stress corrosion cracking is not yet well understood at the fundamental level. Improved mechanistic knowledge of SCC is needed to identify the important microstructural and material property changes accompanying the initiation stage of cracking that are precursory to failure [1–3]. Using high resolution in situ stress measurement, we report the corrosion-induced tensile stress generation, leading to plasticity during the Al corrosion in alkaline …

Impact Of Advection Process In Simulating The Dynamics Of Diffusion-Controlled Irreversible Fast/Moderate/Slow Bimolecular-Reactive Systems, Maruti Mudunuru, Kalyana Nakshatrala

Society of Engineering Science 51st Annual Technical Meeting Archive

Diffusion-controlled bimolecular reactions arise in various branches of natural sciences [1], chemically reacting systems [2], and contaminant transport [3]. Based on the kinetics of the chemical reaction, they are broadly classified in to three categories: fast, moderate, and slow [4]. Herein, we are interested in the dynamics of a (fast/moderate/slow) bimolecular reaction given by the following stoichiometric relationship [5]: nA A + nB B −→ nC C In this discussion, we shall present a computational framework to simulate the dynamics of an irreversible bimolecular advection–diffusion–reaction (ADR) system within the context of low-order mixed finite element method. Most importantly, we shall …

Historical Vegetation Of Three Salmon-Bearing Watersheds In The Interior Columbia River Basin, Tyanna Smith

PSU McNair Scholars Online Journal

Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that past practices, such as logging and grazing, can have on the current landscape. This paper describes research and the synthesis of material on the environmental history and watershed characteristics for three watersheds located within spawning and rearing areas for Chinook salmon in the Grande Ronde River Basin in Northeast Oregon: upper Grande Ronde River, Catherine Creek, and Minam River. The Grande Ronde Basin is critical spawning …

Front Matter Volume 8, 2014, Mcnair Scholars Program

PSU McNair Scholars Online Journal

Front matter includes program background, Table of Contents, and a complete listing of 2014 Portland State McNair Scholars.

Blood-Suckers! The Concepts Revisionist And Anti-Revisionist Mythology Introduced By The Vampire- And Werewolf-Tetralogy Underworld (2003-2012), Stefan L. Arvidsson

Journal of Religion & Film

By undertaking a structuralist influenced analysis of the vampire- and werewolf-tetralogy Underworld the author argues for the usefulness of the concept “revisionist mythology” and “anti-revisionist mythology” in the study of the history of religion in general and in the study of popular mythology in specific. These concepts point to dramaturgical, but also ethical and ideological, changes within the world of commercial pop-mythological artefacts. The article focuses on certain aesthetic aspects of the tetralogy that unveil counter-cultural traits that might be labelled socialist. The article ends with speculations about the causes for the strong revisionistic and anti-revisionistic trends that are taking …

The Failure Of A Pseudo-Christian Community In A Nation-State In Crisis: 28 Days Later, Karl E. Martin

Journal of Religion & Film

This essay argues that the central group of survivors of the Rage plague in Danny Boyle’s 28 Days Later (2002) constitutes a nascent Christian community. This community is formed when the four survivors band together around a common commitment to protect the most vulnerable among them. However, this community fails to provide an alternative to the nation-state because, in its search for protection, it flees into the arms of the nation-state and chooses to answer the violence of the nation-state with violence of its own in order to survive. Christian faith and practice exist in the film only under the …

The Minimum Electrical Field That Can Be Detected By A Biological Membrane—Thermal Noise Limit, Fatemeh Ahmadpoor, Pradeep Sharma, Liping Liu

Society of Engineering Science 51st Annual Technical Meeting Archive

Thermal electrical noise in living cells is considered as the minimum threshold for several biological response mechanisms that pertain to electric fields. Existing models that purport to explain and interpret this phenomena yield perplexing results. In the simplest model, the biomembrane is considered as a linear dielectric which yields an equilibrium noise level that is several orders of magnitude larger than that is observed experimentally. An alternative approach of estimating the thermal noise as the Nyquist noise of a resistor within a finite frequency bandwidth yields little physical insight. In this study, we argue that the nonlinear dielectric behavior must …

Theoretical Study Of Biological Membrane Response To Temperature Gradients At The Single Cell Level, Lior Atia, Sefi Givli

Society of Engineering Science 51st Annual Technical Meeting Archive

Recent experimental studies provide evidence for the existence of a spatially nonuniform temperature field in living cells and in particular in their plasma membrane. These findings have led to the development of a new and exciting field: thermal biology at the single-cell level. This study examines theoretically a specific aspect of this field, i.e. how temperature gradients at the single cell level affect the phase behavior and geometry of heterogeneous membranes. We address this issue by utilizing the Onsager reciprocal relations combined with a simple model for a binary lipid mixture. We demonstrate that even small temperature variations along the …

Biological Cells Adhesion Mediated By Receptors–Ligands Binding, Ben Nadler

Society of Engineering Science 51st Annual Technical Meeting Archive

Cell adhesion plays a vital role in many cell activities. The motivation to model cell adhesion is to study important biological processes, such as cell spreading, cell aggregation, tissue formation, and cell adhesion to biomaterials. This study provides important insight into cell adhesion, which can lead to improve regenerative medicine and tissue formation techniques. In this study, we focus on modeling the adhesion of biological cells mediated by receptors–ligands binding and the diffusivity of the receptor on the cell membrane surface. The ability of receptors to diffuse on the cell membrane surface yields a very unique and complicated adhesion mechanism, …

The Significance Of Somatosensory Stimulation To The Hand: Implications For Occupational Therapy Practice, Guy L. Mccormack

The Open Journal of Occupational Therapy

The hands contain numerous nerve endings that are intimately connected to the brain. Mounting evidence supports the concept that willful manipulation of objects contributes to expansion or reorganization of the somatosensory cortex and can produce therapeutic outcomes. In the past decade, research has demonstrated that cortical plasticity can continue throughout adulthood. Brain plasticity is a core principle that demonstrates the ability of the central nervous system to respond to stimuli and modify its structural organization and function as an adaptive response. Occupation-based interventions, which engage the use of the hands, are conceived in this article as a “mindbody” experience because …

An Eriophyid Mite-Transmitted Plant Virus Contains Eight Genomic Rna Segments With Unusual Heterogeneity In The Nucleocapsid Protein, Satyanarayana Tatineni, Anthony J. Mcmechan, Everlyne N. Wosula, Stephen N. Wegulo, Robert A. Graybosch, Roy French, Gary L. Hein

Department of Plant Pathology: Faculty Publications

Eriophyid mite-transmitted, multipartite, negative-sense RNA plant viruses with membrane-bound spherical virions are classified in the genus Emaravirus. We report here that the eriophyid mite-transmitted Wheat mosaic virus (WMoV), an Emaravirus, contains eight genomic RNA segments, the most in a known negative-sense RNA plant virus. Remarkably, two RNA 3 consensus sequences, encoding the nucleocapsid protein, were found with 12.5% sequence divergence, while no heterogeneity was observed in the consensus sequences of additional genomic RNA segments. The RNA-dependent RNA polymerase, glycoprotein precursor, nucleocapsid, and P4 proteins of WMoV exhibited limited sequence homology with the orthologous proteins of other emaraviruses, while …

Fractal Growth On The Surface Of A Planet And In Orbit Around It, Ioannis Haranas, Ioannis Gkigkitzis, Athanasios Alexiou

Physics and Computer Science Faculty Publications

Fractals are defined as geometric shapes that exhibit symmetry of scale. This simply implies that fractal is a shape that it would still look the same even if somebody could zoom in on one of its parts an infinite number of times. This property is also called self-similarity with several applications including nano-pharmacology and drug nanocarriers. We are interested in the study of the properties of fractal aggregates in a microgravity environment above an orbiting spacecraft. To model the effect we use a complete expression for the gravitational acceleration. In particular on the surface of the Earth the acceleration is …

Ovcs Literary Magazine Viii 2014, Tracee Reiser, David Cruz, Jennifer Cunningham, Megan Hulsart, Melanie Argueta, Colin Forsyth, Maura Hallisey, Michelle Behr, Katherine Ericson

Community Partnerships Literary Magazines

No abstract provided.

Analysis Of Differential Mrna And Mirna Expression In An Alzheimer’S Disease Mouse Model, Amanda Hazy, Matthew Dalton

Other Undergraduate Scholarship

Research has shown that changes in gene expression play a critical role in the development of Alzheimer’s Disease (AD). Our project will evaluate genome-wide RNA expression patterns from brain and blood in an AD mouse model. This analysis will provide insight regarding the mechanisms of AD pathology as well as determine a possible diagnostic tool utilizing RNA expression patterns found in the blood as biomarkers for AD.

Ciis Today, Fall 2014 Issue, California Institiute Of Integral Studies

CIIS Today

This volume is the Fall 2014 issue of CIIS Today, the Magazine of the California Institute of Integral Studies.

College Of Science And Mathematics Newsletter, Fall 2014, College Of Science And Mathematics, Wright State University

College of Science and Mathematics Newsletters

This 8 page newsletter discusses various happenings within the College of Science and Mathematics. It begins with a letter from the dean, and continues on with news, events, alumni news, and other community news.

Lower-Extremity Joint Kinematics And Muscle Activations During Semi-Reclined Cycling At Different Workloads In Healthy Individuals, Kamyar Momeni, Pouran D. Faghri, Martinus Evans

Open Access Author Fund Awardees' Articles

Background

A better understanding of lower-extremity muscles’ activation patterns and joint kinematics during different workloads could help rehabilitation professionals with prescribing more effective exercise regimen for elderly and those with compromised muscles. We examined the relative contribution, as well as activation and co-activation patterns, of lower-extremity muscles during semi-reclined cycling at different workloads during a constant cadence.

Methods

Fifteen healthy novice cyclists participated at three 90-second cycling trials with randomly assigned workloads of 0, 50, and 100 W, at a constant cadence of 60 rpm. During all trials, electromyograms were recorded from four lower-extremity muscles: rectus femoris (RF), biceps femoris …

It’S In The Mix. An Exploratory Study Into The Experiences Of Children, Parents And Staff In The Provision Of A Mixed Age Group Model In A West Dublin Early Years’ Setting., Helena Goodwin

Dissertations

The main aim of this study is to explore the perceptions and experiences of children, parents and staff participating in a mixed-age model of early year’s provision using a qualitative approach. The researcher will take an approach which will aim to interpret and clarify the participant’s experiences.

Using semi-structured interviews, a focus group and an observation of practice the study will address questions such as what were the perceptions of the children, staff and parents experiencing a mixed age group model. Has the mixed-age model proved to be advantageous and/or challenging to the community of the service? How could the …

Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Global climate change is altering the breeding phenology of many organisms, and one reported consequence of warmer average temperatures is earlier breeding times in migratory songbirds of north temperate latitudes. Less studied are the potential interactions between earlier breeding and social behavior in colonial species. We investigated how breeding time, as measured by colony initiation dates across the entire summer, in Cliff Swallows (Petrochelidon pyrrhonota) of southwestern Nebraska, USA, changed over a 30-year period and could be predicted by climatic variables, year, and colony size. Mean colony initiation date became earlier over the study, with variation best predicted …

Stonehill Alumni Magazine Summer/Fall 2014, Stonehill College Office Of Communications And Media Relations

Stonehill Alumni Magazine

This issue of the magazine includes the following features:

• One Common Cause: At the forefront of the fight against breast cancer, four Stonehill women are making scientific discoveries, funding research and community screenings and helping those coping with the disease. By Maura King Scully
• Courses with a Twist: Stonehill professors are making old topics new and interesting with dynamic teaching methods that bring subjects to life. By Tracey Palmer
• Going to the Chapel: In collaboration with Rev. Robert Kruse, C.S. C. '5 5 In the College's early days, the main chapel was in a cramped converted basement. Today, Stonehill is …

October 2014 Quicknotes, Southern Adventist University

QuickNotes – Advancement e-Newsletter

QuickNotes is an e-newsletter that comes from Advancement at Southern Adventist University. October 2014 editions features the article "Pointing You to the Living Water".