Digital Commons Network^™

Discovery Of Alpha-Gal-Containing Antigens In North American Tick Species Believed To Induce Red Meat Allergy, Gary Crispell, Scott P. Commins, Stephanie A. Archer-Hartman, Shailesh Choudhary, Guha Dharmarajan, Parastoo Azadi, Shahid Karim

Faculty Publications

Development of specific IgE antibodies to the oligosaccharide galactose-α-1, 3-galactose (α-gal) following tick bites has been shown to be the source of red meat allergy. In this study, we investigated the presence of α-gal in four tick species: the lone-star tick (Amblyomma americanum), the Gulf-Coast tick (Amblyomma maculatum), the American dog tick (Dermacentor variabilis), and the black-legged tick (Ixodes scapularis) by using a combination of immunoproteomic approach and, carbohydrate analysis. Anti-α-gal antibodies identified α-gal in the salivary glands of both Am. americanum and Ix. scapularis, while Am. maculatum and De. variabilis …

Machine Learning For Prediction Of Sudden Cardiac Death In Heart Failure Patients With Low Left Ventricular Ejection Fraction: Study Protocol For A Retrospective Multicentre Registry In China, Fanqi Meng, Zhihua Zhang, Xiaofeng Hou, Zhiyong Qian, Yao Wang, Yanhong Chen, Yilian Wang, Ye Zhou, Zhen Chen, Xiwen Zhang, Jing Yang, Jinlong Zhang, Jianghong Guo, Kebei Li, Lu Chen, Ruijuan Zhuang, Hai Jiang, Weihua Zhou, Shaowen Tang, Yongyue Wei, Jiangang Zou

Faculty Publications

Introduction: Left ventricular ejection fraction (LVEF) ≤35%, as current significant implantable cardioverter-defibrillator (ICD) indication for primary prevention of sudden cardiac death (SCD) in heart failure (HF) patients, has been widely recognised to be inefficient. Improvement of patient selection for low LVEF (≤35%) is needed to optimise deployment of ICD. Most of the existing prediction models are not appropriate to identify ICD candidates at high risk of SCD in HF patients with low LVEF. Compared with traditional statistical analysis, machine learning (ML) can employ computer algorithms to identify patterns in large datasets, analyse rules automatically and build both linear and …

Floodwater Impact On Galveston Bay Phytoplankton Taxonomy, Pigment Composition And Photo-Physiological State Following Hurricane Harvey From Field And Ocean Color (Sentinel-3a Olci) Observations, Eurico D'Sa

Faculty Publications

Phytoplankton taxonomy, pigment composition and photo-physiological state were studied in Galveston Bay (GB), Texas (USA), following the extreme flooding associated with Hurricane Harvey (25-29 August 2017) using field and satellite ocean color observations. The percentage of chlorophyll a (Chl a) in different phytoplankton groups was determined from a semi-analytical IOP (inherent optical property) inversion algorithm. The IOP inversion algorithm revealed the dominance of freshwater species (diatom, cyanobacteria and green algae) in the bay following the hurricane passage (29 September 2017) under low salinity conditions associated with the discharge of floodwaters into GB. Two months after the hurricane (29-30 October 2017), …

Morphological And Physiological Characteristics Of Endornavirus-Infected And Endornavirus-Free Near-Isogenic Lines Of Bell Pepper (Capsicum Annuum), C. Escalante, R. A. Valverde

Faculty Publications

Plant endornaviruses are persistent viruses that infect plants without causing symptoms. Although endornaviruses have been reported in many economically important plant species, little is known about the effect they have on their hosts. Bell pepper endornavirus (BPEV) has been reported in cultivated peppers (Capsicum spp.). In commercial cultivars of bell pepper (C. annuum) grown in the United States, this virus is found at prevalence rates of 100%. Two bell pepper near-isogenic lines (NILs), one BPEV-infected and the other BPEV-free, were generated and used to investigate the type of symbiotic relationship between BPEV and bell pepper. Selected morphological and physiological characteristics …

Temporal Trends In Cardiovascular Hospital Discharges Following A Mass Chlorine Exposure Event In Graniteville, South Carolina, Ashley V. Howell, John E. Vena, Bo Cai, Daniel T. Lackland, Lucy Ingram, Andrew B. Lawson, Erik R. Svendsen

Faculty Publications

Background: On January 6, 2005, a train derailed in Graniteville, South Carolina, releasing nearly 60,000 kg of toxic chlorine gas. The disaster left nine people dead and was responsible for hundreds of hospitalizations and outpatient visits in the subsequent weeks. While chlorine gas primarily affects the respiratory tract, a growing body of evidence suggests that acute exposure may also cause vascular injury and cardiac toxicity. Here, we describe the incidence of cardiovascular hospitalizations among residents of the zip codes most affected by the chlorine gas plume, and compare the incidence of cardiovascular discharges in the years leading up to the …

Cardiorespiratory Fitness And The Risk Of First Acute Myocardial Infarction: The Hunt Study, Rajesh Shigdel, Håvard Dalen, Xuemei Sui, Carl J. Lavie, Ulrik Wisløff, Linda Ernstsen

Faculty Publications

Background

The majority of studies evaluating cardiorespiratory fitness (CRF) as a cardiovascular risk factor use cardiovascular mortality and not cardiovascular disease events as the primary end point, and generally do not include women. The aim of this study was to investigate the association of estimated CRF (eCRF) with the risk of first acute myocardial infarction (AMI).

Methods and Results

We included 26 163 participants (51.5% women) from the HUNT study (Nord‐Trøndelag Health Study), with a mean age of 55.7 years, without cardiovascular disease at baseline. Baseline eCRF was grouped into tertiles. AMI was derived from hospital records and deaths from …

Infant Social Avoidance Predicts Autism But Not Anxiety In Fragile X Syndrome, Jane E. Roberts, Hayley Crawford, Elizabeth A. Will, Abigail L. Hogan, Samuel Dale Mcquillin, Bridgette L. Tonnsen, Shannon O'Connor, Douglas A. Roberts, Alexis M. Brewe

Faculty Publications

Objective: Autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and anxiety are three of the most common childhood psychiatric disorders. Early trajectories of social avoidance have been linked with these psychiatric disorders in previous studies, but it remains unclear how social avoidance differentially predicts comorbid disorders in a high-risk genetic subgroup. Here, we delineate the association between trajectories of social avoidance from infancy and subsequent ASD, ADHD, and anxiety outcomes at preschool in children with fragile X syndrome (FXS), a well-characterized single-gene disorder highly associated with social avoidance as well as elevated rates of ASD, ADHD, and anxiety.

Method: Males with …

Comparison Of Methods Used To Estimate The Global Burden Of Disease Related To Undernutrition And Suboptimal Breastfeeding, Alexander C. Mclain, Edward A. Frongillo Jr., Sonja Y. Hess, Ellen G. Piwoz

Faculty Publications

The Global Burden of Disease study (GBD) is an ambitious effort to estimate the disease burden attributable to various risk factors. The results from the GBD are used around the world to monitor the UN established Sustainable Development Goals, set health policies and research strategies, among others. The GBD along with other studies, such as those from the Maternal Child Epidemiology Estimation Group and the Lancet Breastfeeding Series Group, produce estimates of the nutrition-related global burden of disease that exhibit considerable differences. These differences are difficult to reconcile due to the estimation methods, which in recent years have substantially increased …

Experimental Evidence Supportive Of The Quantum Dna Model, F. Matthew Mihelic

Faculty Publications

The DNA molecule can be modeled as a quantum logic processor in which electron spin qubits are held coherently in each nucleotide in a logically and thermodynamically reversible enantiomeric symmetry, and can be coherently conducted along the pi-stacking interactions of aromatic nucleotide bases, while simultaneously being spin-filtered via the helicity of the DNA molecule. Entangled electron pairs can be separated by that spin-filtering, held coherently at biological temperatures in the topologically insulated nucleotide quantum gates, and incorporated into separate DNA strands during DNA replication. Two separate DNA strands that share quantum entangled electrons can be mitotically divided into individual cells, …

Prevalence And Risk Factors Of Postpartum Depression Within One Year After Birth In Urban Slums Of Dhaka, Bangladesh, Rashidul Azad, Rukhshan Fahmi, Sadichhya Shrestha, Hemraj Joshi, Mehedi Hasan, Abdullah Nurus Salam Khan, Mohiuddin Ahsanul Kabir Chowdhury, Shams El Arifeen, Sk Masum Billah

Faculty Publications

Postpartum depression (PPD) is a serious pubic health concern and known to have the adverse effects on mother’s perinatal wellbeing; and child’s physical and cognitive development. There were limited literatures on PPD in Bangladesh, especially in urban slum context. The aim of this study was to assess the burden and risk factors of PPD among the urban slum women. A cross-sectional study was conducted between November-December 2017 in three urban slums on 376 women within first 12 months of postpartum. A validated Bangla version of Edinburgh Postnatal Depression Scale was used to measure the depression status. Respondent’s socio-economic characteristics and …

Perspective: Challenges In Use Of Adolescent Anthropometry For Understanding The Burden Of Malnutrition, Alison Tumilowicz, Ty Beal, Lynnette M. Neufeld, Edward A. Frongillo Jr.

Faculty Publications

Improving nutritional status during adolescence is an opportunity to improve the lives of this generation and the next. Estimating the burden of malnutrition at a population level is fundamental to targeting interventions and measuring progress over time, and for adolescents, we usually depend on survey data and the 2007 WHO Growth Reference to do so. There is substantial risk of misguided conclusions regarding adolescent prevalence estimates, however, when underlying methodological limitations of the indicators and reference are not adequately considered. We use national prevalence estimates among girls and young women 10-22 y of age from the 2014 State of Food …

Assessing Natural And Mechanical Dune Performance In A Post-Hurricane Environment, Jean T. Ellis, Mayra Alejandra Roman-Rivera

Faculty Publications

The purpose of this study is to document the geomorphic evolution of a mechanical dune over approximately one year following its installation and compare it to the recovery of a natural dune following the impact of Hurricane Matthew (2016). During the study period, the dunes’ integrity was tested by wave and wind events, including king tides, and a second hurricane (Irma, 2017), at the end of the study period. Prior to the impact of the second hurricane, the volumetric increase of the mechanical and natural dune was 32% and 75%, respectively, suggesting that scraping alone is not the optimal protection …

Longitudinal Homogenization Of The Microbiome Between Both Occupants And The Built Environment In A Cohort Of United States Air Force Cadets, Anukriti Sharma, Miles Richardson, Lauren Cralle, Christopher E. Stamper, Juan P. Maestre, Kelly A. Stearns-Yoder, Teodor T. Postolache, Katherine L. Bates, Kerry A. Kinney, Lisa A. Brenner, Christopher A. Lowry, Jack A. Gilbert, Andrew J. Hoisington

Faculty Publications

The microbiome of the built environment has important implications for human health and wellbeing; however, bidirectional exchange of microbes between occupants and surfaces can be confounded by lifestyle, architecture, and external environmental exposures. Here, we present a longitudinal study of United States Air Force Academy cadets (n = 34), which have substantial homogeneity in lifestyle, diet, and age, all factors that influence the human microbiome. We characterized bacterial communities associated with (1) skin and gut samples from roommate pairs, (2) four built environment sample locations inside the pairs’ dormitory rooms, (3) four built environment sample locations within shared spaces …

Tetrahydrocannabinol Reduces Hapten-Driven Mast Cell Accumulation And Persistent Tactile Sensitivity In Mouse Model Of Allergen-Provoked Localized Vulvodynia, Beebie Boo, Rohit Kamath, Erica Arriaga-Gomez, Jasmine Landry, Elizabeth Emanuel, Sookyong Joo, Marietta Sald Montivero, Tijana Martinov, Brian T. Fife, Devavani Chatterjea

Faculty Publications

Vulvodynia is a remarkably prevalent chronic pain condition of unknown etiology. An increase in numbers of vulvar mast cells often accompanies a clinical diagnosis of vulvodynia and a history of allergies amplifies the risk of developing this condition. We previously showed that repeated exposures to oxazolone dissolved in ethanol on the labiar skin of mice led to persistent genital sensitivity to pressure and a sustained increase in labiar mast cells. Here we sensitized female mice to the hapten dinitrofluorobenzene (DNFB) dissolved in saline on their flanks, and subsequently challenged them with the same hapten or saline vehicle alone for ten …

Do Aquatic Macrophytes Limit The Invasion Potential Of Exotic Species In Pantanal Grasslands?, Francielli Bao, Tracy Elsey-Quirk, Marco Antonio De Assis, Evaldo Benedito De Souza, Arnildo Pott

Faculty Publications

No abstract provided.

An Ensemble Of Lipoxygenase Structures Reveals Novel Conformations Of The Fe Coordination Sphere, Svetlana Pakhomova, William E. Boeglin, David B. Neau, Sue G. Bartlett, Alan R. Brash, Marcia E. Newcomer

Faculty Publications

© 2019 The Protein Society The regio- and stereo-specific oxygenation of polyunsaturated fatty acids is catalyzed by lipoxygenases (LOX); both Fe and Mn forms of the enzyme have been described. Structural elements of the Fe and Mn coordination spheres and the helical catalytic domain in which the metal center resides are highly conserved. However, animal, plant, and microbial LOX each have distinct features. We report five crystal structures of a LOX from the fungal plant pathogen Fusarium graminearum. This LOX displays a novel amino terminal extension that provides a wrapping domain for dimerization. Moreover, this extension appears to interfere with …

Patchy Fires Promote Regeneration Of Longleaf Pine (Pinus Palustris Mill.) In Pine Savannas, Kevin M. Robertson, William J. Platt, Charles E. Faires

Faculty Publications

© 2019 by the authors. Research Highlights: Spatial patterns of fire spread and severity influence survival of juvenile pines in longleaf pine savannas. Small areas that do not burn during frequent fires facilitate formation of patches of even-aged longleaf pine juveniles. These regeneration patches are especially associated with inner portions of openings (gaps) and where canopy trees have died in recent decades. Patterns of prescribed fire can thus have an important influence on stand dynamics of the dominant tree in pine savannas. Background and Objectives: Savannas are characterized by bottlenecks to tree regeneration. In pine savannas, longleaf pine is noted …

Access Before Evidence And The Price Of The Fda's New Drug Authorities, Erika Lietzan

Faculty Publications

Sometimes drug innovation seems to happen in reverse. Patients enjoy a treatment for years even though the treatment has not been approved by the FDA or proven safe and effective to the FDA's standards. (Sometimes this happens because the FDA has declined to take enforcement action.) The agency encourages companies to perform the work necessary to satisfy the United States "gold standard" for new drug approval, however, by promising exclusivity in the marketplace. When a company does this work, at considerable expense, the results are predictable. The new drug is expensive, and patients and payers (and sometimes policymakers) are outraged. …

Frozen Pre-Embryo Practice In Missouri, Mary M. Beck, L. "Joanna" Beck Wilkinson

Faculty Publications

McQueen v. Gadberry was an Eastern District dissolution dispute over frozen pre-implantation embryos formed from McQueen’s eggs and Gadberry’s sperm. The St. Louis County trial court found the pre-embryos to be marital property of a special character and awarded them jointly to each of the former spouses. The appellate court affirmed. McQueen is an important decision because the finding that embryos are marital property was an issue of first impression that affects many Missouri families. Infertility is a common problem, couples frequently utilize assisted reproductive technologies (ART) to form families, and the extra frozen pre-implantation embryos (hereinafter pre-embryos) have fueled …

Arabinosyl Deacetylase Modulates The Arabinoxylan Acetylation Profile And Secondary Wall Formation, Lanjun Zhang, Chengxu Gao, Frederic Mentink-Vigier, Lu Tang, Dongmei Zhang, Shaogan Wang, Shaoxue Cao, Zuopeng Xu, Xiangling Liu, Tuo Wang, Yihua Zhou, Baocai Zhang

Faculty Publications

© 2019 ASPB. Acetylation, a prevalent modification of cell-wall polymers, is a tightly controlled regulatory process that orchestrates plant growth and environmental adaptation. However, due to limited characterization of the enzymes involved, it is unclear how plants establish and dynamically regulate the acetylation pattern in response to growth requirements. In this study, we identified a rice (Oryza sativa) GDSL esterase that deacetylates the side chain of the major rice hemicellulose, arabinoxylan. Acetyl esterases involved in arabinoxylan modification were screened using enzymatic assays combined with mass spectrometry analysis. One candidate, DEACETYLASE ON ARABINOSYL SIDECHAIN OF XYLAN1 (DARX1), is specific for arabinosyl …

A Gradient Of Pollination Specialization In Three Species Of Bolivian Centropogon, Laura P. Lagomarsino, Nathan Muchhala

Faculty Publications

© 2019 Botanical Society of America Premise: Closely related plant species with overlapping ranges often experience competition for pollination services. Such competition can select for divergence in floral traits that attract pollinators or determine pollen placement. While most species in Centropogon (Campanulaceae: Lobelioideae) have flowers that suggest adaptation to bat or hummingbird pollination, actual pollinators are rarely documented, and a few species have a mix of traits from both pollination syndromes. We studied the pollination biology of a “mixed-syndrome” species and its co-occurring congeners to examine the relationship between floral traits and visitation patterns for Centropogon. Methods: Fieldwork at two …

Longleaf Pine Patch Dynamics Influence Ground-Layer Vegetation In Old-Growth Pine Savanna, Maria Paula Mugnani, Kevin M. Robertson, Deborah L. Miller, William J. Platt

Faculty Publications

© 2019 by the authors. Old-growth longleaf pine savannas are characterized by diverse ground-layer plant communities comprised of graminoids, forbs, and woody plants. These communities co-exist with variable-aged patches containing similar-aged trees of longleaf pine (Pinus palustris Mill.). We tested the conceptual model that physical conditions related to the cycle of longleaf pine regeneration (stand structure, soil attributes, fire effects, and light) influence plant species' composition and spatial heterogeneity of ground-layer vegetation. We used a chrono-sequence approach in which local patches represented six stages of the regeneration cycle, from open areas without trees (gaps) to trees several centuries old, based …

Genetics Of Variable Disease Expression Conferred By Inverse Gene-For-Gene Interactions In The Wheat-Parastagonospora Nodorum Pathosystem, Amanda R. Peters Haugrud, Zengcui Zhang, Jonathan K. Richards, Timothy L. Friesen, Justin D. Faris

Faculty Publications

The wheat-Parastagonospora nodorum pathosystem involves the recognition of pathogen-secreted necrotrophic effectors (NEs) by corresponding wheat NE sensitivity genes. This inverse gene-for-gene recognition leads to necrotrophic effector-triggered susceptibility and ultimately septoria nodorum blotch disease. Here, we used multiple pathogen isolates to individually evaluate the effects of the host gene-NE interactions Tan spot necrosis1-Stagonospora nodorum ToxinA (Tsn1-SnToxA), Stagonospora nodorum necrosis1-Stagonospora nodorum Toxin1 (Snn1-SnTox1), and Stagonospora nodorum necrosis3-B genome homeolog1-Stagonospora nodorum Toxin3 (Snn3-B1-SnTox3), alone and in various combinations, to determine the relative importance of these interactions in causing disease. Genetic analysis of a recombinant inbred wheat population inoculated separately with three P. nodorum …

Effect Of Alkali-Enhanced Biochar On Silicon Uptake And Suppression Of Gray Leaf Spot Development In Perennial Ryegrass, Meng Wang, Jim J. Wang, Negar D. Tafti, Clayton A. Hollier, Gerald Myers, Xudong Wang

Faculty Publications

Silicon (Si) is known to alleviate biotic and abiotic stress, and to reduce the development of fungal diseases in a number of different pathosystems. Biochar-based Si fertilizers, especially highly efficient alkali-enhanced biochar for recycling phytolith, has been recently proposed as a stress-alleviating amendment but its evaluation on plant disease development has not been investigated. In this study, several biochar–based Si fertilizers including raw biochar without alkaline enhancement (0 KB), alkali-enhanced biochars with KOH (10 KB), CaO (10CB), and K 2 CO 3 (10K2B) along with commonly-used mineral Si fertilizer wollastonite (WO) and calcium silicate slag (SL) were evaluated in a …

Zinc Toxicity And Iron-Sulfur Cluster Biogenesis In Escherichia Coli, Huangen Ding

Faculty Publications

While zinc is an essential trace metal in biology, excess zinc is toxic to organisms. Previous studies have shown that zinc toxicity is associated with disruption of the (4Fe-4S] clusters in various dehydratases in Escherichia coli. Here, we report that the intracellular zinc overload in E. coli cells inhibits iron-sulfur cluster biogenesis without affecting the preassembled iron-sulfur clusters in proteins. Among the housekeeping iron-sulfur cluster assembly proteins encoded by the gene cluster iscSUA-hscBA-fdx-iscX in E. coli cells, the scaffold IscU, the iron chaperone IscA, and ferredoxin have strong zinc binding activity in cells, suggesting that intracellular zinc overload inhibits iron-sulfur …

Homoeostatic Maintenance Of Nonstructural Carbohydrates During The 2015–2016 El Niño Drought Across A Tropical Forest Precipitation Gradient, Lee Turin Dickman, Nate G. Mcdowell, Charlotte Grossiord, Adam D. Collins, Brett T. Wolfe, Matteo Detto, S. Joseph Wright, José A. Medina-Vega, Devin Goodsman, Alistair Rogers, Shawn P. Serbin, Jin Wu, Kim S. Ely, Sean T. Michaletz, Chonggang Xu, Lara Kueppers, Jeffrey Q. Chambers

Faculty Publications

Nonstructural carbohydrates (NSCs) are essential for maintenance of plant metabolism and may be sensitive to short- and long-term climatic variation. NSC variation in moist tropical forests has rarely been studied, so regulation of NSCs in these systems is poorly understood. We measured foliar and branch NSC content in 23 tree species at three sites located across a large precipitation gradient in Panama during the 2015–2016 El Niño to examine how short- and long-term climatic variation impact carbohydrate dynamics. There was no significant difference in total NSCs as the drought progressed (leaf P = 0.32, branch P = 0.30) nor across …

Functional Screening Of Genes From A Halophyte Wild Rice Relative Porteresia Coarctata In Arabidopsis Model Identifies Candidate Genes Involved In Salt Tolerance, Venkata R. Mangu, Disna Ratnasekera, Jonalyn C. Yabes, Rod A. Wing, Niranjan Baisakh

Faculty Publications

High soil salinity is one of the most important environmental stressors, and is an increasing concern under the alarmingly global climate uncertainties. Salinity affects the growth and productivity of food crops, including rice, and ultimately threatens global food security and sustainability. Conventional breeding efforts to develop salt tolerant rice varieties utilizing its primary gene pool have resulted in limited success due to the mutligenic inheritance of salt tolerance traits. On the other hand, Porteresia coarctata, the only halophyte wild rice, offers tremendous opportunities to improve salt tolerance in rice. However, reports on the characterization of its rich genetic resources are …

Comparison Of Anthracnose Resistance With The Presence Of Two Scar Markers Associated With The Rca2 Gene In Strawberry, Melinda A. Miller-Butler, Barbara J. Smith, Brian R. Kreiser, Eugene K. Blythe

Faculty Publications

Strawberry anthracnose diseases are caused primarily by three Colletotrichum species: C. acutatum J.H. Simmonds, C. fragariae A.N. Brooks, and C. gloeosporioides (Penz.) Penz. & Sacc. Molecular markers are being used in breeding programs to identify alleles linked to disease resistance and other positive agronomic traits. In our study, strawberry cultivars and breeding germplasm with known anthracnose susceptibility or resistance to the three anthracnose-causing Colletotrichum species were screened for two sequence characterized amplified region (SCAR) markers linked to the Rca2 gene. The Rca2 resistant allele SCAR markers were associated with varying degrees of significance for a strawberry plant’s anthracnose resistance to …

Balanced Parallel Exploration Of Orthogonal Regions, Wyatt Clements, Costas Busch, Limeng Pu, Daniel Smith, Hsiao Chun Wu

Faculty Publications

We consider the use of multiple mobile agents to explore an unknown area. The area is orthogonal, such that all perimeter lines run both vertically and horizontally. The area may consist of unknown rectangular holes which are non-traversable internally. For the sake of analysis, we assume that the area is discretized into N points allowing the agents to move from one point to an adjacent one. Mobile agents communicate through face-to-face communication when in adjacent points. The objective of exploration is to develop an online algorithm that will explore the entire area while reducing the total work of all k …

The Effects Of Ambient Temperature And Lighting Intensity On Wheel-Running Behavior In A Diurnal Rodent, The Nile Grass Rat (Arvicanthis Niloticus), Garrett M. Fogo, Alyssa M. Goodwin, Ohanes S. Khacherian, Brandi J. Ledbetter, Andrew J. Gall

Faculty Publications

Environmental conditions, such as the light-dark cycle and temperature, affect the display of circadian rhythmicity and locomotor activity patterns in mammals. Here, we tested the hypothesis that manipulating these environmental conditions would affect wheel-running activity patterns in a diurnal rodent, the Nile grass rat (Arvicanthis niloticus). Grass rats are diurnal in the field, however, a subset switch from a day-active pattern to a night-active pattern of activity after the introduction of a running wheel. The mechanism of this chronotype switch remains largely unknown. In the present study, grass rats were presented with running wheels in 12:12 light-dark conditions. First, subjects …