Microbiology Commons^™

Distinct Distribution Of Archaea From Soil To Freshwater To Estuary: Implications Of Archaeal Composition And Function In Different Environments, Hualong Wang, Raven Bier, Laura Zgleszewski, Marc Peipoch, Emmanuel Omondi, Atanu Mukherjee, Feng Chen, Chuanlun Zhang, Jinjun Kan

Agricultural and Environmental Sciences Faculty Research

In addition to inhabiting extreme territories, Archaea are widely distributed in common environments spanning from terrestrial to aquatic environments. This study investigated and compared archaeal community structures from three different habitats (representing distinct environments): agriculture soils (from farming system trials FST, PA, United States), freshwater biofilms (from White Clay Creek, PA, United States), and estuary water (Chesapeake Bay, United States). High-throughput sequencing of 16S rRNA genes indicated that Thaumarchaeota, Euryarchaeota, Nanoarchaeota, Crenarchaeota, and Diapherotrites were the commonly found dominant phyla across these three environments. Similar to Bacteria, distinct community structure and distribution patterns for Archaea were observed in soils vs. …

Graphene-Based Electrochemical Aptasensor For The Detection Of Salmonella Typhimurium, Shalini Muniandy

Student Works (2020-2029)

Recent foodborne outbreaks in multiple locations necessitate the continuous development of highly sensitive and specific biosensors that offer rapid and sensitive detection of foodborne pathogens. The emergence of electrochemical aptasensor which is a compact analytical device with a combination of an aptamer as the biorecognition element integrated on the transducer surface created a breakthrough in the detection of foodborne bacterial pathogens. Graphene has emerged as a promising nanomaterial for reliable detection of pathogenic bacteria due to its exceptional properties such as high electrical conductivity, large surface to volume ratio, high mechanical strength and its unique interactions with DNA bases of …

Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Temperate forests of eastern North America are subject to multiple invasions from non-native species that have the potential to drive long-term dynamics in biodiversity. Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) is an invasive plant in many deciduous forests, and management efforts often focus on removing this species to initiate native species restoration. Agrilus planipennis Fairmaire (emerald ash borer; Coleoptera: Buprestidae) is a non-native insect pest that has caused substantial loss of ash trees (Fraxinus spp. L.) in North America. Our goal was to understand how the herbaceous layer in an old-growth forest responded to the removal of …

Overview Of Plaster Creek Stewards Transpiration Rate Across Different Species Over 3 Years, Ana Singh, David P. Warners

Faculty and Professional Research

No abstract provided.

Diverse Community Of Arsenic Resistant Bacteria Display Arsenate Reducing Capabilities, Stephanie Maeda

Undergraduate Honors Theses

Naturally found in soil and water environments arsenic is toxic to many organisms, carcinogenic to humans, and poses a significant public health risk. Yet communities of bacteria found thriving in arsenic ridden environments have evolved mechanisms to tolerate and exploit both oxidation states of this heavy metal (arsenite and arsenate). As the site of an old arsenic mine, Black Mountain Open Space Park in San Diego, California has yielded concentrations of arsenic in the soil between 111-14,800 ppm. Exceeding average arsenic soil concentrations and levels considered safe in the environment by the World Health Organization, we sought to characterize the …

Endothelial Cell Contributions To Covid-19, Alexandra E. Oxford, Fabio Halla, Evan B. Robertson, Brad E. Morrison

Biology Faculty Publications and Presentations

Understanding of the clinical, histological and molecular features of the novel coronavirus 2019 (Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)) has remained elusive. Coronavirus disease 2019 (COVID-19) caused by this virus has unusual clinical presentation with regard to other related coronaviruses. Recent reports suggest that SARS-CoV-2, unlike other related viruses, infects and replicates within endothelial cells, which may explain a significant portion of the observed clinical pathology. Likewise, mounting evidence associates vascular and endothelial cell dysfunction with increased mortality. This review focuses on understanding how endothelial cell pathology is caused by SARS-CoV-2 at the molecular and cellular levels and how …

Cryo‑Electron Microscopy Structure Of The 70s Ribosome From Enterococcus Faecalis, Eileen L. Murphy, Kavindra V. Singh, Bryant Avila, Torsten Kleffmann, Steven T. Gregory, Barbara E. Murray, Kurt L. Krause, Reza Khayat, Gerwald Jogl

Publications and Research

Enterococcus faecalis is a gram-positive organism responsible for serious infections in humans, but as with many bacterial pathogens, resistance has rendered a number of commonly used antibiotics ineffective. Here, we report the cryo-EM structure of the E. faecalis 70S ribosome to a global resolution of 2.8 Å. Structural differences are clustered in peripheral and solvent exposed regions when compared with Escherichia coli, whereas functional centres, including antibiotic binding sites, are similar to other bacterial ribosomes. Comparison of intersubunit conformations among five classes obtained after three-dimensional classification identifies several rotated states. Large ribosomal subunit protein bL31, which forms intersubunit bridges to …

Microbial Diversity In The Sawmill Environment: Implications On The Health Of Sawmill Workers And Merchants, Nigeria, Ebere J. Okafor-Elenwo Ej, Odaro S. Imade Os, Osazee E. Izevbuwa Eo

Journal of Bioresource Management

There is an increasingly high suspicion of occupational health diseases amongst workers in sawmill factories. Hence this study aimed to determine the microbial diversity in some sawmill factories in Okada, Edo State, Nigeria to evaluate potential implications of the factory’s processing area on the health of the workers and wood merchants. Bacteria and fungi count in the bioaerosols within the processing area of each factory was performed with the passive air sampling technique. While in the sawdust samples, microbial counts were carried out with the pour plate technique. Identification of the microbes was performed with macroscopic and microscopic examinations as …

A Functional K+ Channel From Tetraselmis Virus 1, A Member Of The Mimiviridae, Kerri Kukovetz, Brigitte Hertel, Christopher R. Schvarcz, Andrea Saponaro, Mirja Manthey, Ulrike Burk, Timo Greiner, Grieg F. Steward, James L. Van Etten, Anna Moroni, Gerhard Thiel, Oliver Rauh

Nebraska Center for Virology: Faculty Publications

Potassium ion (K+) channels have been observed in diverse viruses that infect eukaryotic marine and freshwater algae. However, experimental evidence for functional K+ channels among these alga-infecting viruses has thus far been restricted to members of the family Phycodnaviridae, which are large, double-stranded DNA viruses within the phylum Nucleocytoviricota. Recent sequencing projects revealed that alga-infecting members of Mimiviridae, another family within this phylum, may also contain genes encoding K+ channels. Here we examine the structural features and the functional properties of putative K+ channels from four cultivated members of Mimiviridae. While all four proteins contain variations …

Sensitivity Of Planktonic Cells Of Staphylococcus Aureus To Elevated Hydrostatic Pressure As Affected By Mild Heat, Carvacrol, Nisin, And Caprylic Acid, Jyothi George, Sadiye Aras, Md Niamul Kabir, Sabrina Wadood, Shahid Chowdhury, Aliyar Cyrus Fouladkhah

Agricultural and Environmental Sciences Faculty Research

Current study investigated effects of elevated hydrostatic pressure exposure in the presence of mild heat and natural antimicrobials against Staphylococcus aureus. Hydrostatic pressure of 350 to 550 MPa with nisin (5000 IU/mL), carvacrol, or caprylic acid (0.5% v/v) were applied for the reduction in four-strain mixture of S. aureus in HEPES buffer at 4 and 40 °C for up to 7 min. Results were statistically analyzed by ANOVA and D-values were additionally calculated using best-fitted linear model. Prior to exposure to treatments at 4 °C, counts of the pathogen were 7.95 ± 0.4 log CFU/mL and were reduced (p < 0.05) to 6.44 ± 0.3 log CFU/mL after 7 min of treatment at 450 MPa. D-value associated with this treatment was 5.34 min (R^{2 …}

Biofilm Forming Ability Of Bacteria Isolated From Dental Caries: With Reference To Streptococcus Species, Sonali Kaustubh Ambulkar, Vidya Tale, Abhijit Jadhav, Komal Kulkarni

Future Dental Journal

Dental caries is formed by the group of microorganisms attached to a tooth surface embedded in a matrix of polymers. Biofilm plays an important role in the development of dental caries, plaque and other periodontal diseases. The present study is aimed to isolate, identify and characterize bacteria from dental caries. The ability of biofilm formation of these isolates was confirmed by Congo red agar method, Tube method and Microtitre plate method. High biofilm-forming bacteria were identified by 16S rRNA sequencing. Streptococcus mutans, Streptococcus anginosus, Enterococcus faecalis and Rothia dentocariosa are the predominant biofilm forming bacteria associated with dental caries.

Human Parainfluenza Virus Fusion Complex Glycoproteins Imaged In Action On Authentic Viral Surfaces, Tara Marcink, Tong Wang, Amédée Des Georges, Matteo Porotto, Anne Moscona

Advanced Science Research Center

Infection by human parainfluenza viruses (HPIVs) causes widespread lower respiratory diseases, including croup, bronchiolitis, and pneumonia, and there are no vaccines or effective treatments for these viruses. HPIV3 is a member of the Respirovirus species of the Paramyxoviridae family. These viruses are pleomorphic, enveloped viruses with genomes composed of single-stranded negative-sense RNA. During viral entry, the first step of infection, the viral fusion complex, comprised of the receptor-binding glycoprotein hemagglutininneuraminidase (HN) and the fusion glycoprotein (F), mediates fusion upon receptor binding. The HPIV3 transmembrane protein HN, like the receptor-binding proteins of other related viruses that enter host cells using …

Did You Wash Your Caving Suit? Cavers’ Role In The Potential Spread Of Pseudogymnoascus Destructans, The Causative Agent Of White-Nose Disease, Violeta Zhelyazkova, Antonia Hubancheva, Georgi Radoslavov, Nia Toshkova, Sebastien J. Puechmaille

International Journal of Speleology

White-Nose Disease (WND) has killed millions of hibernating bats in the US and Canada. Its causative agent, the fungus Pseudogymnoascus destructans was introduced to North America, but is native to Europe and Asia, where it is not associated with mass mortality. Although it is nearly impossible to eradicate an emerging wildlife disease, research on P. destructans spread mechanisms can aid in prevention of new introductions and development of better environmental management strategies. It is of particular importance to quantify the potential role of people visiting caves (cavers, tourists, bat researchers, etc.) whom inadvertently move P. destructans spores between sites, and …

Mechanism Of Translation Inhibition By Type Ii Gnat Toxin Atat2, Stepan V Ovchinnikov, Dmitry Bikmetov, Alexei Livenskyi, Marina Serebryakova, Brendan Wilcox, Kyle Mangano, Dmitrii I Shiriaev, Ilya A Osterman, Petr V Sergiev, Sergei Borukhov, Nora Vazquez-Laslop, Alexander S Mankin, Konstantin Severinov, Svetlana Dubiley

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Type II toxin-antitoxins systems are widespread in prokaryotic genomes. Typically, they comprise two proteins, a toxin, and an antitoxin, encoded by adjacent genes and forming a complex in which the enzymatic activity of the toxin is inhibited. Under stress conditions, the antitoxin is degraded liberating the active toxin. Though thousands of various toxin-antitoxins pairs have been predicted bioinformatically, only a handful has been thoroughly characterized. Here, we describe the AtaT2 toxin from a toxin-antitoxin system from Escherichia coli O157:H7. We show that AtaT2 is the first GNAT (Gcn5-related N-acetyltransferase) toxin that specifically targets charged glycyl tRNA. In vivo, the AtaT2 …

Does The Presence Of Multiple Β-Lactamases In Gram-Negative Bacilli Impact The Results Of Antimicrobial Susceptibility Tests And Extended-Spectrum Β-Lactamase And Carbapenemase Confirmation Methods?, Fred C. Tenover, Caitlin M. Dela Cruz, Scott Dewell, Victoria M. Le, Isabella A. Tickler

Biology Faculty Publications

Objectives: Many multidrug-resistant Gram-negative bacilli (MDR-GNB) harbour multiple β-lactamases. The aim of this study was to assess the impact of multiple β-lactamase carriage on the accuracy of susceptibility tests and extended-spectrum β-lactamase (ESBL) and carbapenemase confirmation methods.

Methods: A total of 50 MDR-GNB, of which 29 carried multiple β-lactamases, underwent broth microdilution (BMD) and disk diffusion (DD) testing as well as confirmation tests for ESBLs and carbapenemases. Whole-genome sequencing (WGS) was used for β-lactamase gene identification.

Results: Categorical agreement of BMD and DD testing results ranged from 86.5 to 97.7% for 10 β-lactam agents. BMD and DD algorithms for ESBL …

Defining The Proteolytic Landscape During Enterovirus Infection., Mohsan Saeed, Sebastian Kapell, Nicholas T Hertz, Xianfang Wu, Kierstin Bell, Alison W Ashbrook, Milica Tesic Mark, Henry A Zebroski, Maxwell L Neal, Malin Flodström-Tullberg, Margaret R Macdonald, John D Aitchison, Henrik Molina, Charles M Rice

Articles, Abstracts, and Reports

Viruses cleave cellular proteins to remodel the host proteome. The study of these cleavages has revealed mechanisms of immune evasion, resource exploitation, and pathogenesis. However, the full extent of virus-induced proteolysis in infected cells is unknown, mainly because until recently the technology for a global view of proteolysis within cells was lacking. Here, we report the first comprehensive catalog of proteins cleaved upon enterovirus infection and identify the sites within proteins where the cleavages occur. We employed multiple strategies to confirm protein cleavages and assigned them to one of the two enteroviral proteases. Detailed characterization of one substrate, LSM14A, a …

The Influence Of Riparian Invasion By The Terrestrial Shrub Lonicera Maackii On Aquatic Macroinvertebrates In Temperate Forest Headwater Streams, Michelle N. Little, Kevin W. Custer, Eric B. Borth, Julia I. Chapman, Mitchell J. Kukla, Corey Kuminecz, Margaret E. Maloney, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

The ecology of headwater streams is tightly linked to the riparian zone through organic matter subsidies which are highly susceptible to alteration due to biological invasion. Lonicera maackii is a non-native shrub that is a highly successful invader of headwater stream riparian zones in the American Midwest. We assessed effects on benthic macroinvertebrates across a gradient of invasion intensity from references sites with minimal invasion to a site that had a very heavy invasion. Benthic macroinvertebrates were sampled throughout the year and compositional differences were assessed using Non-metric Multidimensional Scaling ordination, and by comparing the prevalence of sensitive (Ephemeroptera, Plectoptera, …

Tick-Borne Pathogens Shape The Native Microbiome Within Tick Vectors, Abdulsalam Adegoke, Deepak Kumar, Cailyn Bobo, Muhammad Imran Rashid, Aneela Zameer Durrani, Muhammad Sohail Sajid, Shahid Karim

Faculty Publications

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Ticks are blood-feeding arthropods and transmit a variety of medically important viral, bacterial, protozoan pathogens to animals and humans. Ticks also harbor a diverse community of microbes linked to their biological processes, such as hematophagy, and hence affect vector competence. The interactions between bacterial and/or protozoan pathogens and the tick microbiome is a black-box, and therefore we tested the hypothesis that the presence of a protozoan or bacterial pathogen will alter the microbial composition within a tick. Hence, this study was designed to define the microbial composition of two tick species, …

Small Molecule Synthetic Carbohydrate Receptors, Marcelo F. Bravo Carranco

Dissertations, Theses, and Capstone Projects

Carbohydrate – receptor interactions are often involved in the attachment of viruses to host cells, and this docking is a necessary step in the virus life cycle that precedes infection and, ultimately, replication. Despite the conserved structures of the glycans involved in docking, they are still considered “undruggable”, meaning these glycans are beyond the scope of conventional pharmacological strategies. Recent advances in the development of synthetic carbohydrate receptors (SCRs) – small molecules that bind carbohydrates – could bring carbohydrate-receptor interactions within the purview of druggable targets. Here we discuss the role of carbohydrate-receptor interactions in viral infection, the evolution of …

1,4-Dioxane Biodegradation In Propanotrophs: Molecular Foundations And Implications For Environmental Remediation, Li Fei

Dissertations

1,4-Dioxane (dioxane) has emerged with an escalating concern given its human carcinogenicity and widespread occurrence in groundwater. Bioremediation is promising as an effective and cost-efficient treatment alternative for in situ or ex situ cleanup of dioxane and co-existing pollutants in the field. Soluble di-iron monooxygenases (SDIMOs) are reputed for their essential roles in initiating the cleavage of dioxane and other pollutants. In this doctoral dissertation, molecular foundations for SDIMOs-mediated dioxane biodegradation are untangled to promote the development and implication of site-specific bioremediation and natural attenuation strategies. This dissertation focused on propanotrophic bacteria given their pivotal roles in dioxane metabolism and …

Study Of A Putative Niche Adapting Operon In Microbes Inhabiting The Gut Of Blood Digesting Animals, Marlene Abouaassi

University Scholar Projects

The sialic acid utilization (SAU) operon is a horizontally acquired gene set that allows bacteria to utilize sialic acid as an alternate source of carbon and nitrogen in the guts of blood eating animals. Sialic acid often occurs as a terminal sugar in complex glycoproteins. It functions in cell signaling and adhesion. Sialic acid is an important component of the cellular envelope of animals. Some microorganisms have evolved to decorate their own surface with sialic acid to evade the host’s immune response (molecular mimicry). The SAU operon encodes enzymes that hydrolyze sialic acid from glycoproteins, transport sialic acid into the …

Study Of A Putative Niche Adapting Operon In Microbes Inhabiting The Gut Of Blood Digesting Animals, Marlene Abouaassi

Honors Scholar Theses

The sialic acid utilization (SAU) operon is a horizontally acquired gene set that allows bacteria to utilize sialic acid as an alternate source of carbon and nitrogen in the guts of blood eating animals. Sialic acid often occurs as a terminal sugar in complex glycoproteins. It functions in cell signaling and adhesion. Sialic acid is an important component of the cellular envelope of animals. Some microorganisms have evolved to decorate their own surface with sialic acid to evade the host’s immune response (molecular mimicry). The SAU operon encodes enzymes that hydrolyze sialic acid from glycoproteins, transport sialic acid into the …

The Effects Of Radical Containing Combustion Derived Particulate Matter In Adult Mouse Respiratory System, Jeffrey Harding

LSU Doctoral Dissertations

Epidemiological data associates high levels of combustion-derived particulate matter (PM) with deleterious respiratory outcomes, but the mechanism underlying those outcomes remains elusive. It has been acknowledged by the World Health Organization that PM exposure contributes to more than 4.2 million all-cause mortalities worldwide each year. Current literature demonstrates that PM exacerbates respiratory diseases, impairs lung function, results in chronic respiratory illnesses, and is associated with increased mortality. The proposed mechanisms revolve around oxidative stress and inflammation promoting pulmonary physiological remodeling. Our data demonstrate that environmentally persistent free radicals (EPFRs) stabilized on the surface of PM are capable of inducing oxidative …

Draft Genome Sequences Of Six Strains Isolated From The Rhizosphere Of Wheat Grown In Cadmium-Contaminated Soil, Vira Hovorukha, Ankita Bhattacharyya, Olga Iungin, Hanna Tashyreva, Victoria Romanovska, Olesia Havyrliuk, Olena Bielikova, Claire Blackwell, Brian Burks, Cara Cothern, Jakia Elliott, Jonathan Hoover, Alexis Jones, Christian Leise, Linda Lowmiller, Ahmed Mohamed, Tiffany Mullen, Ethan Nettleton, Karshanda Polk, Benny Tran, Teresa Tran, Manuel Vega, Landon Ware, Emily Welch, Leandra Williams, Madison Woodward, Kaylin Young, Olga Mavrodi, Oleksandr Tashyrev, Dmitri Mavrodi

Faculty Publications

This study presents high-quality draft genome assemblies of six bacterial strains isolated from the roots of wheat grown in soil contaminated with cadmium. The results of this study will help to elucidate at the molecular level how heavy metals affect interactions between beneficial rhizobacteria and crop plants.

Complete Genome Sequences Of Cluster P1 And Cluster C1 Mycobacterium Smegmatis Phages Jung And Ronan, Richard Van, William Nie, Feruz Abdela, Bardia Eivazi, Dolores Kickbusch, Michael Finkle, Cody Cris, Matthew Rubinstein, Baylor Akavan, Mahdeed Raja, Jessica Vergara, Wilson Andrade, Abimael Barajas, Jocelyn Sanchez, Maria Duenas, Kurt Regner, Christy Strong, Philippos K. Tsourkas, Jay Barilla

Life Sciences Faculty Research

We present the complete genome sequences of Mycobacterium smegmatis phages Jung and Ronan, isolated from soil in Las Vegas, Nevada. The phages were isolated and annotated by students enrolled in a course for undergraduate research experience (CURE). Jung is a cluster P1 mycobacteriophage, while Ronan is in cluster C1.

Glycan-Dependent Adherence And Skin Colonization Of Staphylococcus Epidermidis Mediated By The Surface Protein Aap., Paroma Roy

Theses & Dissertations

Skin-dwelling coagulase-negative staphylococci (CoNS), a group of bacteria that includes Staphylococcus epidermidis, has been implicated to promote skin immunity and antimicrobial defense and prohibit colonization of skin by pathogens like S. aureus. As a skin inhabitant, S. epidermidis lives in tight association with corneocytes, the cells that constitute the uppermost layer of the skin epidermis. Yet the molecular mechanism responsible for adhesion of S. epidermidis to corneocytes remains poorly understood. Our study indicated that Accumulation-associated protein (Aap), a cell-wall anchored, fibrillar adhesin mediates bacterial-host interaction, demonstrated by significantly higher corneocyte binding by Aap-positive 1457 mutants as compared to …

Isolation And Characterization Of Bacteria In A Toluene-Producing Enrichment Culture Derived From Contaminated Groundwater At A Louisiana Superfund Site, Madison Mikes

LSU Master's Theses

In an effort to better understand the role that various microbes may play in toluene production, bacteria from a toluene-producing enrichment culture derived from contaminated groundwater at a Superfund site were cultivated and isolated on low nutrient solid media. A total of 14 solid medium formulations containing varying pH ranges, carbon sources, solidifying agents, and incubation gas headspaces were used to obtain 278 isolates in pure culture. Isolated bacteria, identified using partial 16S rRNA gene sequences, were most closely related with the genera Anoxybacillus, Azospira, Bacillus, Bradyrhizobium, Cellulosimicrobium, Micrococcus, and Propionicimonas.

Further attempts …

Preliminary Evidence Of The Role Of Medial Prefrontal Cortex In Self-Enhancement: A Transcranial Magnetic Stimulation Study, Birgitta Taylor-Lillquist, Vivek Kanpa, Maya Crawford, Mehdi El Filali, Julia Oakes, Alex Jonasz, Amanda Disney, Julian Keenan

Department of Biology Faculty Scholarship and Creative Works

Humans employ a number of strategies to improve their position in their given social hierarchy. Overclaiming involves presenting oneself as having more knowledge than one actually possesses, and it is typically invoked to increase one’s social standing. If increased expectations to possess knowledge is a perceived social pressure, such expectations should increase bouts of overclaiming. As the medial prefrontal cortex (MPFC) is sensitive to social pressure and disruption of the MPFC leads to decreases in overclaiming, we predicted that transcranial magnetic stimulation (TMS) applied to the MPFC would reduce overclaiming and the effects would be enhanced in the presence of …

How Does Molecular Biology Help To Identify Plant Disease?, Madina Akramova

International Programs

This study examines a process of plant disease diagnostics in light of a particular method of molecular biology - polymerase chain reaction.

Isolation, Enumeration And Antibiotic Profiling Of Vibrio Vulnificus And V. Parahaemolyticus From Coastal Virginia, Stanley E. Peyton Jr.

Masters Theses, 2020-current

Vibrio vulnificus and V. parahaemolyticus are gram-negative, halophilic bacteria that reside in estuarine waters and are associated with infections in humans. These bacteria can cause gastroenteritis through their presence in raw fish and shellfish consumed by humans. V. vulnificus can also produce wound infections leading to severe septicemia, and in some cases, death if not treated promptly. With increasing incidence of infections due to these two organisms, research efforts have focused on potential reservoirs and environmental conditions that can increase human exposure to, and infection, with these species of bacteria. This study was conducted in order to examine the role …