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The Hope College Department Of Biology: The First 50+ Years, Christopher C. Barney

Faculty Publications

The Hope College Department of Biology was founded in 1899 with the appointment of the first Professor of Biology at Hope, Samuel Mast. During the first 50+ years of the Biology Department, there were eight total faculty members in the department, including Frances Koeman, the first female faculty member in the natural sciences. Four faculty members, Mast, Frank Patterson, Oscar Thompson, and Teunis Vergeer were primarily responsible for developing the department’s curriculum and programs, with Mast and Vergeer also carrying out published research. The department was housed primarily in Van Raalte Hall and the Science Building (now Lubbers Hall) for …

Employing A Hysteresis Approach To Analyze Shifts In Tree Physiological Thresholds In Response To Drought, Mauro Brum, Annie Deslauriers, Matthew A. Vadeboncoeur, Tanner Frost, David Moore, Caroline Rodrigues Da Silva, Daniel B. Metcalfe, Heidi Asbjornsen

Faculty Publications

Drought‐induced tree mortality underscores the need for improved physiological models to predict tree responses to water stress. We employed a hysteresis modelling approach analyzing diel water absorption and desorption cycles to understand drought‐induced shifts in physiological thresholds. We applied this approach to sap flow (Js), stem diameter fluctuation (SDF), stem volumetric water content fluctuation (SVWCF), and vapour pressure deficit (VPD), datasets from two throughfall reduction experiments in contrasting ecosystems: a cloud forest (Peru) and a temperate forest (USA). Using a generalised transcendental equation, we quantified five diurnal hysteresis loops (Js:VPD, Js:SDF, Js:SVWCF, SDF:VPD, SVWCF:VPD) and derived hysteresis parameters (centroids, area, …

International Society Of Sports Nutrition Position Stand: Nutritional Concerns Of The Female Athlete, Ralf Jäger, Jeffery L. Heileson, Sidney Abou Sawan, Broderick L. Dickerson, Megan Leonard, Richard B. Kreider, Chad M. Kerksick, Stephen M. Cornish, Darren G. Candow, Dean M. Cordingley, Scott C. Forbes, Grant M. Tinsley, Tindaro Bongiovanni, Roberto Cannataro, Bill I. Campbell, Shawn M. Arent Ph.D., Cscs*D, Fissn, Facsm, Fnak, Jeffrey R. Stout, Douglas S. Kalman, Jose Antonio

Faculty Publications

Position Statement: The International Society of Sports Nutrition (ISSN) presents this position based on a critical examination of the literature surrounding the effects of long-chain omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation on exercise performance, recovery, and brain health. This position stand is intended to provide a scientific foundation for athletes, dietitians, trainers, and other practitioners regarding the effects of supplemental ω-3 PUFA in healthy and athletic populations. The following conclusions represent the official position of the ISSN: Athletes may be at a higher risk for ω-3 PUFA insufficiency. Diets rich in ω-3 PUFA, including supplements, are effective strategies for …

The Role Of Biological Plasticity In Model-Based Translational Research, Jessica A. Bolker

Faculty Publications

Reports of low replicability and translatability of biomedical research have called the value of animal models into question. The problems are real, but abandoning animal research is not the solution. Rather, improving the translatability of model-based research requires attention to relevant differences between humans and models, and to attributes of the models themselves that are essential to both robust science and effective translation. One is biological plasticity, the responsiveness of individual organisms to complex and variable environments. Though under-represented in model systems (for both historical and practical reasons), plasticity is central to human biology. While there are good reasons to …

Sound Marks, Deborah R. Gerhardt, Jon J. Lee

Faculty Publications

A lion roars just before a film rolls. A doughboy giggles. A giant green man laughs a hearty, "Ho, Ho, Ho." These iconic sounds are all federally registered as trademarks. They identify specific brands and distinguish their products and services from the competition. Human brains treat sounds like these as categorization tools and cognitive shortcuts—ideal trademark symbols. But what about the sounds your favorite toys or electronic devices make? Or those made by a fictional character in the latest blockbuster?

This Article tackles these issues and others. We push back against the widely-held belief that all unconventional trademarks—product designs, colors, …

Toward A Simulation Model Complexity Measure, J. Scott Thompson, Douglas D. Hodson, Michael R. Grimaila, Nicholas Hanlon, Richard Dill

Faculty Publications

Is it possible to develop a meaningful measure for the complexity of a simulation model? Algorithmic information theory provides concepts that have been applied in other areas of research for the practical measurement of object complexity. This article offers an overview of the complexity from a variety of perspectives and provides a body of knowledge with respect to the complexity of simulation models. The key terms model detail, resolution, and scope are defined. An important concept from algorithmic information theory, Kolmogorov complexity, and an application of this concept, normalized compression distance, are used to indicate the possibility of measuring changes …

Ice-Crystal-Templated “Accordion-Like” Cellulose Nanofiber/Mxene Composite Aerogels For Sensitive Wearable Pressure Sensors, Wangwang Xu, Qinglin Wu, Jaegyoung Gwon, Jin Woo Choi

Faculty Publications

Exfoliated MXene nanosheets are integrated with cellulose nanofibers (CNFs) to form composite aerogels with high electric conductivity. The combination of CNFs and MXene nanosheets forms a unique “accordion-like” hierarchical architecture with MXene-CNF pillared layers through ice-crystal templating. Benefiting from the special “layer-strut” structure, the MXene/CNF composite aerogels have low density (50 mg/cm3), excellent compressibility and recoverability, as well as superior fatigue resistance (up to 1000 cycles). When being used as a piezoresistive sensor, the composite aerogel exhibits high sensitivity upon different strains, stable sensing performance with various compressive frequencies, broad detection range, and quick responsiveness (0.48 s). Moreover, the piezoresistive …

Topical Application Of An Irreversible Small Molecule Inhibitor Of Lysyl Oxidases Ameliorates Skin Scarring And Fibrosis, Nutan Chaudhari, Alison D. Findlay, Andrew W. Stevenson, Tristan D. Clemons, Yimin Yao, Amar Joshi, Sepidar Sayar, Gordon Wallace, Suzanne Rea, Priyanka Toshniwal, Zhenjun Deng, Philip E. Melton, Nicole Hortin, K. Swaminathan Iyer, Wolfgang Jarolimek, Fiona M. Wood, Mark W. Fear

Faculty Publications

Scarring is a lifelong consequence of skin injury, with scar stiffness and poor appearance presenting physical and psychological barriers to a return to normal life. Lysyl oxidases are a family of enzymes that play a critical role in scar formation and maintenance. Lysyl oxidases stabilize the main component of scar tissue, collagen, and drive scar stiffness and appearance. Here we describe the development and characterisation of an irreversible lysyl oxidase inhibitor, PXS-6302. PXS-6302 is ideally suited for skin treatment, readily penetrating the skin when applied as a cream and abolishing lysyl oxidase activity. In murine models of injury and fibrosis, …

Influence Of Guideline Operationalization On Youth Activity Prevalence In The International Children’S Accelerometry Database, Catherine Gammon, Andrew J. Atkin, Kirsten Corder, Ulf Ekelund, Bjorge Herman Hansen, Lauren B. Sherar, Lars Bo Anderson, Sigmund Anderssen, Rachel Davey, Pedro C. Hallal, Russell Jago, Susi Kriemler, Peter Lund Kristensen, Soyang Kwon, Kate Nothstone, Russell R. Pate Ph.D., J. O. Salmon, Luis B. Sardinha, Esther M.F. Sluijs

Faculty Publications

Introduction

The United Kingdom and World Health Organization recently changed their youth physical activity (PA) guidelines from 60 min of moderate- to vigorous-intensity PA (MVPA) every day, to an average of 60 min of MVPA per day, over a week. The changes are based on expert opinion due to insufficient evidence comparing health outcomes associated with different guideline definitions. This study used the International Children’s Accelerometry Database to compare approaches to calculating youth PA compliance and associations with health indicators.

Methods

Cross-sectional accelerometer data (n = 21,612, 5–18 yr) were used to examine compliance with four guideline definitions: daily …

Bibliometric Analysis Of Coronavirus Disease 2019 Medical Research Production From Saudi Arabia, Amr A. Jamal, Samar Binkheder, Raniah N. Aldekhyyel, Jwaher Almulhem, Shabana Tharkar, Afaf Ali Batis, Layal Hneiny

Faculty Publications

In response to the coronavirus disease 2019 (COVID-19) pandemic and as an attempt to fill the knowledge gap related to this topic, extensive research in this area has been published. The Kingdom of Saudi Arabia, as one of the countries affected by the pandemic, has contributed to the growing body of scientific literature related to COVID-19. To measure research contribution produced by Saudi Arabian affiliated researchers, we conducted a bibliometric analysis of COVID-19 research across two databases: the Web of Science and Scopus. Analysis was conducted on February 2, 2021 and included all relevant COVID-19-related publications (n = 1510). …

Exploring Thermal State In Mixed Immersive Virtual Environments, Sanaz Saeidi, Girish Rentala, Tracey Rizzuto, Tianzhen Hong, Neil Johannsen, Yimin Zhu

Faculty Publications

Combining immersive virtual environment (IVE) with a controlled environment is a potential solution for analyzing human thermal experience during building design. Existing studies in this field have not adequately analyzed scenarios involving stabilized comfortable and uncomfortable temperature conditions using both thermal state votes and physiological responses, or the influence of the seasons. By combining IVE with a climate chamber, called mixed IVE (MIVE) in this study, experiments were conducted to test the hypothesis that participants' virtual experience did not significantly alter their thermal experience compared to their in-situ experience. Response variables were the control temperature distribution, the thermal state vote …

Virtual Traffic Signals: Safe, Rapid, Efficient And Autonomous Driving Without Traffic Control, Zhao Zhang, Feng Liu, Brian Wolshon, Yu Sheng

Faculty Publications

Connected and autonomous vehicles (CAV) will open the future to vast possibilities in transportation, most of which have yet to be imagined. As these new technologies emerge, they also have the potential to render many of today's most common transportation control methods irrelevant. In this paper, concepts of connected and autonomous are applied to coordinate and synchronize the arrival and departure of vehicles at intersections; effectively ending the need for traffic signals. Under a set of 'autonomous rules of operation', vehicles can be kept in near-continuous motion while also maintaining safe separation, creating a system of 'virtual traffic signal' (VTS). …

Reinvigorating A Technical Countering Weapons Of Mass Destruction Distance Learning Graduate Certificate Program, James C. Petrosky, Gaiven Varshney, Jeremy Slagley, Sara Shaghaghi

Faculty Publications

Current Countering Weapons of Mass Destruction (CWMD) demands can be divided broadly into policy and science. The science of chemical, biological, and radiological/nuclear weapons informs the limits of development, production, employment, operation, detection, risk characterization, human and material protection, and medical intervention. In short, the science of weapons of mass destruction (WMD) should precede and inform the development of policy. It is to this end that the Air Force Institute of Technology (AFIT) CWMD program was re-established, providing a technical educational option for practitioners to understand the science behind a very technically challenging subject.

Ramipril Blunts Glycerol-Induced Acute Renal Failure In Rats Through Its Antiapoptosis, Anti-Inflammatory, Antioxidant, And Renin-Inhibiting Properties, Adeolu Alex Adedapo, Ehizogie Ruth Osaretin, Olufunke Olubunmi Falayi, Ademola Adetokunbo Oyagbemi, Blessing Seun Ogunpolu, Temidayo Olutayo Omobowale, Oluwafemi Omoniyi Oguntibeju, Momoh Audu Yakubu

Faculty Publications

Acute kidney injury (AKI) is a malady with a sudden onset resulting in buildup of waste matters in the body, but a specific cure hasn't been found as a lasting solution to AKI. In this study, ramipril was evaluated for its potential therapy in glycerol-induced AKI in rats. Twenty animals were divided into four groups of five animals each. Group I was the control while group II was given glycerol on day 8 only, groups III and IV were administered with pioglitazone (reference drug) and ramipril for seven days respectively and on day 8 received glycerol. On the ninth day, …

Applying Spatial Video Geonarratives And Physiological Measurements To Explore Perceived Safety In Baton Rouge, Louisiana, Alina Ristea, Michael Leitner, Bernd Resch, Judith Stratmann

Faculty Publications

Spatial crime analysis, together with perceived (crime) safety analysis have tremendously benefitted from Geographic Information Science (GISc) and the application of geospatial technology. This research study discusses a novel methodological approach to document the use of emerg-ing geospatial technologies to explore perceived urban safety from the lenses of fear of crime or crime perception in the city of Baton Rouge, USA. The mixed techniques include a survey, spatial video geonarrative (SVG) in the field with study participants, and the extraction of moments of stress (MOS) from biosensing wristbands. This study enrolled 46 participants who completed geonarratives and MOS detection. A …

Migrating Genes: Using Adna And Archaeological Data To Explain Migration In The Casas Grandes Region Of Northern Mexico, Meradeth Snow, Michael T. Searcy

Faculty Publications

Migration as an archaeological topic has addressed huge distances, such as the colonization of the Americas, as well as smaller regions, such as the peopling of specific sites. The use of genetics as a medium to enhance our understanding of population movement can be an asset. There are potential pitfalls, however, such as the misrepresentation of DNA ranging across the landscape without human vectors or motivations. Genetic data must be interpreted through the lens of all available data from the site and surrounding region in order to understand how it its into the potential for human migration. These ideas will …

Meeting Report Of The Third Annual Tri-Service Microbiome Consortium Symposium, J Philip Karl, Robyn A. Barbato, Laurel A. Doherty, Aarti Gautam, Sarah M. Glaven, Robert J. Kokoska, Dagmar Leary, Rebecca Mickol, Matthew A. Perisin, Andrew J. Hoisington, Edward J. Van Opstal, Vanessa Varaljay, Nancy Kelley-Loughnane, Camilla A. Mauzy, Michael S. Goodson, Jason W. Soares

Faculty Publications

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among U.S. Department of Defense (DoD) organizations and to facilitate resource, material and information sharing among consortium members. The 2019 annual symposium was held 22–24 October 2019 at Wright-Patterson Air Force Base in Dayton, OH. Presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) human microbiomes; 2) transitioning products into Warfighter solutions; 3) environmental microbiomes; 4) engineering microbiomes; and 5) microbiome simulation and characterization. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted …

American Heart Association Epi|Lifestyle Scientific Sessions: 2020 Meeting Highlights, Alexander C. Razavi, Véronique Gingras, Erin D. Michos, Ann Marie Navar, Sherry Ann Brown, Erin Delker, Kathryn Foti, Stéphanie Harrison, Yifei Lu, Jovia L. Nierenberg, Jewel Scott Phd, Rn, Fnp-C, Olive Tang, Alvin G. Thomas, Ruth Alma Turkson-Ocran, Amelia Wallace, Mingyu Zhang, Kristie J. Lancaster, Pamela L. Lutsey, Elizabeth Selvin

Faculty Publications

No abstract provided.

American Heart Association Epi|Lifestyle Scientific Sessions: 2020 Meeting Highlights, Alexander C. Razavi, Véronique Gingras, Erin D. Michos, Ann Marie Navar, Sherry Ann Brown, Erin Delker, Kathryn Foti, Stéphanie Harrison, Yifei Lu, Jovia L. Nierenberg, Jewel Scott Phd, Rn, Fnp-C, Olive Tang, Alvin G. Thomas, Ruth Alma Turkson-Ocran, Amelia Wallace, Mingyu Zhang, Kristie J. Lancaster, Pamela L. Lutsey, Elizabeth Selvin

Faculty Publications

No abstract provided.

The Athletic Gut Microbiota, Alex E. Mohr, Ralf Jäger, Katie C. Carpenter, Chad M. Kerksick, Martin Purpura, Jeremy R. Townsend, Nicholas P. West, Katherine Black, Michael Gleeson, David B. Pyne, Shawn D. Wells, Shawn M. Arent Ph.D., Cscs*D, Fissn, Facsm, Fnak, Richard B. Kreider, Bill I. Campbell, Laurent Bannock, Jonathan Scheiman, Craig J. Wissent, Marco Pane, Douglas S. Kalman, Jamie N. Pugh, Carmen P. Ortega-Santos, Jessica A. Ter Haar, Paul J. Arciero, Jose Antonio

Faculty Publications

The microorganisms in the gastrointestinal tract play a significant role in nutrient uptake, vitamin synthesis, energy harvest, inflammatory modulation, and host immune response, collectively contributing to human health. Important factors such as age, birth method, antibiotic use, and diet have been established as formative factors that shape the gut microbiota. Yet, less described is the role that exercise plays, particularly how associated factors and stressors, such as sport/exercise-specific diet, environment, and their interactions, may influence the gut microbiota. In particular, high-level athletes offer remarkable physiology and metabolism (including muscular strength/power, aerobic capacity, energy expenditure, and heat production) compared to sedentary …

Improving Natural Product Research Translation: From Source To Clinical Trial, Barbara C. Sorkin, Adam J. Kuszak, Gregory Bloss, Naomi K. Fukagawa, Freddie Ann Hoffman, Mahtab Jafari, Bruce Barrett, Paula N. Brown, Frederic D. Bushman, Steven J. Casper, Floyd H. Chilton, Christopher S. Coffey, Mario G. Ferruzzi, D. Craig Hopp, Mairead Kiely, Daniel Lakens, John B. Macmillan, David O. Meltzer, Marco Pahor, Jeffrey Paul, Kathleen Pritchett-Corning, Sara K. Quinney, Barbara Rehermann, Kenneth D.R. Setchell, Nisha S. Sipes, Jacqueline M. Stephens, D. Lansing Taylor, Hervé Tiriac, Michael A. Walters, Dan Xi, Giovanna Zappalá, Guido F. Pauli

Faculty Publications

© 2019 Federation of American Societies for Experimental Biology While great interest in health effects of natural product (NP) including dietary supplements and foods persists, promising preclinical NP research is not consistently translating into actionable clinical trial (CT) outcomes. Generally considered the gold standard for assessing safety and efficacy, CTs, especially phase III CTs, are costly and require rigorous planning to optimize the value of the information obtained. More effective bridging from NP research to CT was the goal of a September, 2018 transdisciplinary workshop. Participants emphasized that replicability and likelihood of successful translation depend on rigor in experimental design, …

Response Of Liver Metabolic Pathways To Ketogenic Diet And Exercise Are Not Additive, Tai Yu Huang, Felicia R. Goldsmith, Scott E. Fuller, Jacob Simon, Heidi M. Batdorf, Matthew C. Scott, Nabil M. Essajee, John M. Brown, David H. Burk, Christopher D. Morrison, Susan J. Burke, J. Jason Collier, Robert C. Noland

Faculty Publications

© Lippincott Williams & Wilkins. Purpose Studies suggest ketogenic diets (KD) produce favorable outcomes (health and exercise performance); however, most rodent studies have used a low-protein KD, which does not reflect the normal- to high-protein KD used by humans. Liver has an important role in ketoadaptation due to its involvement in gluconeogenesis and ketogenesis. This study was designed to test the hypothesis that exercise training (ExTr) while consuming a normal-protein KD (NPKD) would induce additive/synergistic responses in liver metabolic pathways. Methods Lean, healthy male C57BL/6J mice were fed a low-fat control diet (15.9% kcal protein, 11.9% kcal fat, 72.2% kcal …

International Comparison Of The Levels And Potential Correlates Of Objectively Measured Sedentary Time And Physical Activity Among Three-To-Four-Year-Old Children, Kaiseree I. Dias, James White, Russell Jago, Greet Cardon, Rachel Davey, Kathleen F. Janz, Russell R. Pate, Jardena J. Puder, John J. Reilly, Ruth Kipping

Faculty Publications

Physical activity (PA) patterns track from childhood through to adulthood. The study aimed to determine the levels and correlates of sedentary time (ST), total PA (TPA), and moderate-to-vigorous PA (MVPA) in preschool-aged children. We conducted cross-sectional analyses of 1052 children aged three-to-four-years-old from six studies included in the International Children’s Accelerometry Database. Multilevel linear regression models adjusting for age, gender, season, minutes of wear time, and study clustering effects were used to estimate associations between age, gender, country, season, ethnicity, parental education, day of the week, time of sunrise, time of sunset, and hours of daylight and the daily minutes …

Naringenin Promotes Thermogenic Gene Expression In Human White Adipose Tissue, Candida J. Rebello, Frank L. Greenway, Frank H. Lau, Yuan Lin, Jacqueline M. Stephens, William D. Johnson, Ann A. Coulter

Faculty Publications

© 2018 The Obesity Society Objective: Naringenin, a citrus flavonoid, prevents diet-induced weight gain and improves glucose and lipid metabolism in rodents. There is evidence that naringenin activates brown fat and increases energy expenditure in mice, but little is known about its effects in humans. The goal of this study was to examine the effects of naringenin on energy expenditure in adipose tissue. Methods: Human white adipocyte cultures (hADSC) and abdominal subcutaneous adipose tissue (pWAT) were treated with naringenin for 7 to 14 days. Expression (quantitative real-time polymerase chain reaction, immunoblotting) of candidate genes involved in thermogenesis and glucose metabolism …

Paper Promises For Drug Innovation, Erika Lietzan

Faculty Publications

Innovation does not stop when a new medicine is launched. Development of new uses for already approved drugs, in particular, can make profound contributions to the public health. Whether a new use is suspected during the initial premarket trials, identified through focused research after approval, or discovered serendipitously by physicians treating patients, however, it requires extensive clinical testing before it can be approved by FDA. This testing takes time and money — three to five years on average, and as much as $300 million. This Article considers the incentives that federal law offers to companies to make this investment: patent …

Comparison Of Thermally Actuated Retro-Diels-Alder Release Groups For Nanoparticle Based Nucleic Acid Delivery, Mohammad Abu-Laban, Raju R. Kumal, Jonathan Casey, Jeff Becca, Daniel Lamaster, Carlos N. Pacheco, Dan G. Sykes, Lasse Jensen, Louis H. Haber, Daniel J. Hayes

Faculty Publications

© 2018 Elsevier Inc. The present study explores alternate pericyclic chemistries for tethering amine-terminal biomolecules onto silver nanoparticles. Employing the versatile tool of the retro-Diels-Alder (rDA) reaction, three thermally-labile cycloadducts are constructed that cleave at variable temperature ranges. While the reaction between furan and maleimide has widely been reported, the current study also evaluates the reverse reaction kinetics between thiophene-maleimide, and pyrrole-maleimide cycloadducts. Density Functional Theorem (DFT) calculations used to model and plan the experiments, predict energy barriers for the thiophene-maleimide reverse reaction to be greatest, and the pyrrole-maleimide barriers the lowest. Based on the computational analyses, it is projected …

Weather And Children’S Physical Activity; How And Why Do Relationships Vary Between Countries?, Flo Harrison, Anna Goodman, Ester M.F. Van Sluijs, Lars Bo Carson, Greet Cardon, Rachel Davey, Kathleen F. Janz, Susi Kriemler, Lynn Molly, Angie S. Page, Russell R. Pate, Jardena J. Puder, Luis B. Sardinha, Anna Timperio, Niels Wedderkopp, Andy P. Jones

Faculty Publications

Background

Globally most children do not engage in enough physical activity. Day length and weather conditions have been identified as determinants of physical activity, although how they may be overcome as barriers is not clear. We aim to examine if and how relationships between children’s physical activity and weather and day length vary between countries and identify settings in which children were better able to maintain activity levels given the weather conditions they experienced.

Methods

In this repeated measures study, we used data from 23,451 participants in the International Children’s Accelerometry Database (ICAD). Daily accelerometer-measured physical activity (counts per minute; …

The Molecular Basis For The Lack Of Inflammatory Responses In Mouse Embryonic Stem Cells And Their Differentiated Cells, William D'Angelo, Chandan Gurung, Dhiraj Acharya, Natalya Ortolano, Fengwei Bai, Yan-Lin Guo

Faculty Publications

We reported previously that mouse embryonic stem cells do not have a functional IFN-based antiviral mechanism. The current study extends our investigation to the inflammatory response in mouse embryonic stem cells and mouse embryonic stem cell–differentiated cells. We demonstrate that LPS, TNF-α, and viral infection, all of which induce robust inflammatory responses in naturally differentiated cells, failed to activate NF-κB, the key transcription factor that mediates inflammatory responses, and were unable to induce the expression of inflammatory genes in mouse embryonic stem cells. Similar results were obtained in human embryonic stem cells. In addition to the inactive state of NF-κB, …

Fundamental Principles Of Tremor Propagation In The Upper Limb, Andrew D. Davidson, Steven Knight Charles

Faculty Publications

Although tremor is the most common movement disorder, there exist few effective tremor-suppressing devices, in part because the characteristics of tremor throughout the upper limb are unknown. To clarify, optimally suppressing tremor requires a knowledge of the mechanical origin, propagation, and distribution of tremor throughout the upper limb. Here we present the first systematic investigation of how tremor propagates between the shoulder, elbow, forearm, and wrist. We simulated tremor propagation using a linear, time-invariant, lumped-parameter model relating joint torques and the resulting joint displacements. The model focused on the seven main degrees of freedom from the shoulder to the wrist …

Thermoreversible And Injectable Abc Polypeptoid Hydrogels: Controlling The Hydrogel Properties Through Molecular Design, Sunting Xuan, Chang Uk Lee, Cong Chen, Andrew B. Doyle, Yueheng Zhang, Li Guo, Vijay T. John, Daniel Hayes, Donghui Zhang

Faculty Publications

© 2015 American Chemical Society. A series of ABC triblock copolypeptoids [i.e., poly(N-allyl glycine)-b-poly(N-methyl glycine)-b-poly(N-decyl glycine) (AMD)] with well-defined structure and varying composition have been synthesized by sequential primary amine-initiated ring-opening polymerization of the corresponding N-substituted N-carboxyanhydride monomers (Al-NCA, Me-NCA, and De-NCA). The ABC block copolypeptoids undergo sol-to-gel transitions with increasing temperature in water and biological media at low concentrations (2.5-10 wt %). The sol-gel transition is rapid and fully reversible with a narrow transition window, evidenced by the rheological measurements. The gelation temperature (Tgel) and mechanical stiffness of the hydrogels are highly tunable: Tgel in the 26.2-60.0 °C range, …