Digital Commons Network^™

Origin Of Complexity In Hemoglobin Evolution, Arvind S. Pillai, Shane A. Chandler, Yang Liu, Anthony V. Signore, Carlos R. Cortez-Romero, Justin L. P. Benesch, Arthur Laganowsky, Jay F. Storz, Georg K. A. Hochberg, Joseph W. Thornton

School of Biological Sciences: Faculty Publications

Most proteins associate into multimeric complexes with specific architectures, which often have functional properties such as cooperative ligand binding or allosteric regulation. No detailed knowledge is available about how any multimer and its functions arose during evolution. Here we use ancestral protein reconstruction and biophysical assays to elucidate the origins of vertebrate hemoglobin, a heterotetramer of paralogous α- and β-subunits that mediates respiratory oxygen transport and exchange by cooperatively binding oxygen with moderate affinity. We show that modern hemoglobin evolved from an ancient monomer and characterize the historical “missing link” through which the modern tetramer evolved—a noncooperative homodimer with high …

Genome Wide Association Study Reveals Plant Loci Controlling Heritability Of The Rhizosphere Microbiome, Siwen Deng, Daniel F. Caddell, Gen Xu, Lindsay Dahlen, Lorenzo Washington, Jinliang Yang, Devin Coleman-Derr

Department of Agronomy and Horticulture: Faculty Publications

Host genetics has recently been shown to be a driver of plant microbiome composition. However, identifying the underlying genetic loci controlling microbial selection remains challenging. Genome-wide association studies (GWAS) represent a potentially powerful, unbiased method to identify microbes sensitive to the host genotype and to connect them with the genetic loci that influence their colonization. Here, we conducted a population-level microbiome analysis of the rhizospheres of 200 sorghum genotypes. Using 16S rRNA amplicon sequencing, we identify rhizosphere-associated bacteria exhibiting heritable associations with plant genotype, and identify significant overlap between these lineages and heritable taxa recently identified in maize. Furthermore, we …

The Trait Repertoire Enabling Cyanobacteria To Bloom Assessed Through Comparative Genomic Complexity And Metatranscriptomics, Huansheng Cao, Yohei Shimura, Morgan M. Steffen, Zhou Yang, Jingrang Lu, Allen Joel, Landon Jenkins, Masanobu Kawachi, Yanbin Yin, Ferran Garcia-Pichel

Food for Health: Publications

Water bloom development due to eutrophication constitutes a case of niche specialization among planktonic cyanobacteria, but the genomic repertoire allowing bloom formation in only some species has not been fully characterized. We posited that the habitat relevance of a trait begets its underlying genomic complexity, so that traits within the repertoire would be differentially more complex in species successfully thriving in that habitat than in close species that cannot. To test this for the case of bloom-forming cyanobacteria, we curated 17 potentially relevant query metabolic pathways and five core pathways selected according to existing ecophysiological literature. The available 113 genomes …

Additional Observations On The Nesting Behavior Of Miscophus (Nitelopterus) Californicus (Ashmead) (Hymenoptera: Crabronidae), Frank E. Kurczewski, Alice J. Abela, Darrell Ubick

Insecta Mundi

Close-up photographs of nest entry, nest closure and prey transport taken on sandy coastal back dunes in Santa Barbara County, CA by Alice J. Abela substantiate and enhance written descriptions of these nesting be­havior components in Miscophus californicus (Ashmead) [=M. laticeps (Ashmead)] (Hymenoptera: Crabronidae). Dictynidae (Dictyna Sundevall or Emblyna Chamberlin) is introduced as a new host family and host spider leg amputation is revealed for the first time for this small miscophine wasp.

Miscophus (Nitelopterus) californicus (Ashmead) (Hymenoptera: Crabronidae) is a small (4.5–7.0 mm) Nearctic miscophine wasp that ranges from California and Arizona north to southern …

Genetic Biocontrol For Invasive Species, John L. Teem, Luke Alphey, Sarah Descamps, Matt P. Edgington, Owain Edwards, Neil Gemmell, Tim Harvey-Samuel, Rachel L. Melnick, Kevin P. Oh, Antoinette J. Piaggio, J. Royden Saah, Dan Schill, Paul Thomas, Trevor Smith, Andrew Roberts

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species are increasingly affecting agriculture, food, fisheries, and forestry resources throughout the world. As a result of global trade, invasive species are often introduced into new environments where they become established and cause harm to human health, agriculture, and the environment. Prevention of new introductions is a high priority for addressing the harm caused by invasive species, but unfortunately efforts to prevent new introductions do not address the economic harm that is presently manifested where invasive species have already become established. Genetic biocontrol can be defined as the release of organisms with genetic methods designed to disrupt the reproduction …

Air Temperature, Carbon Dioxide, And Ammonia Assessment Inside A Commercial Cage Layer Barn With Manure-Drying Tunnels, W Zheng, Y Xiong, R S. Gates, K W. Koelkebeck

Department of Animal Science: Faculty Publications

Understanding the air temperature distribution, ammonia (NH₃) and carbon dioxide (CO₂) levels in poultry housing systems are crucial to poultry health, welfare, and productivity. In this study, 4 Intelligent Portable Monitoring Units and 7 temperature sensors were installed inside and between the cages and above 2 minimum ventilation fans of a commercial stacked-deck cage laying hen house in the Midwest United States (425,000 laying hens) to continuously monitor the interior environment over a 6-month period. During cold conditions (March 12th–May 22nd), there was a variation noted, with barn center temperatures consistently being highest in the longitudinal …

Devil In The Detail Of Scotus Ruling On Workplace Bias Puts Lgbtq Rights And Religious Freedom On Collision Course, Kelsy Burke, Emily Kazyak

Department of Sociology: Faculty Publications

orientation and gender identity was cheered by LGBTQ people and allies. Indeed, the June 15 decision represents a big win in the fight for LGBTQ equality. But buried towards the end of a 33-page majority opinion written by conservative stalwart Justice Neil Gorsuch is a sober warning that those celebrating the decision might have initially missed. In his reading, the religious beliefs of an employer may “supersede” the Title VII protections now being extended to the LGBTQ community in its resolution of Bostock v. Clayton County. It is an issue that courts will likely have to decide on a case-by-case …

Horizontal Gene Transfer Of Fhb7 From Fungus Underlies Fusarium Head Blight Resistance In Wheat, Hongwei Wang, Silong Sun, Wenyang Ge, Lanfei Zhao, Bingqian Hou, Kai Wang, Zhongfan Lyu, Liyang Chen, Shoushen Xu, Jun Guo, Min Li, Peisen Su, Xuefeng Li, Guiping Wang, Cunyao Bo, Xiaojian Fang, Wenwen Zhuang, Xinxin Cheng, Jianwen Wu, Luhao Dong, Wuying Chen, Wen Li, Guilian Xiao, Jinxiao Zhao, Yongchao Hao, Ying Xu, Yu Gao, Wenjing Liu, Yanhe Liu, Huayan Yin, Jiazhu Li, Xiang Li, Yan Zhao, Xiaoqian Wang, Fei Ni, Xin Ma, Anfei Li, Steven S. Xu, Guihua Bai, Eviatar Nevo, Caixia Gao, Herbert Ohm, Lingrang Kong

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Fusarium head blight (FHB), a fungal disease caused by Fusarium species that produce food toxins, currently devastates wheat production worldwide, yet few resistance resources have been discovered in wheat germplasm. Here, we cloned the FHB resistance gene Fhb7 by assembling the genome of Thinopyrum elongatum, a species used in wheat distant hybridization breeding. Fhb7 encodes a glutathione S-transferase (GST) and confers broad resistance to Fusarium species by detoxifying trichothecenes through de-epoxidation. Fhb7 GST homologs are absent in plants, and our evidence supports that Th. elongatum has gained Fhb7 through horizontal gene transfer (HGT) from an endophytic Epichloë species. Fhb7 introgressions …

Dynamic Transcriptomic And Phosphoproteomic Analysis During Cell Wall Stress In Aspergillus Nidulans, Cynthia Chelius, Walker Huso, Samantha Reese, Alexander Doan, Stephen Lincoln, Kelsi Lawson, Boa Tran, Raj Purohit, Trevor Glaros, Ranjan Srivastava, Steven D. Harris, Mark R. Marten

Center for Plant Science Innovation: Faculty Publications

The fungal cell-wall integrity signaling (CWIS) pathway regulates cellular response to environmental stress to enable wall repair and resumption of normal growth. This complex, interconnected, pathway has been only partially characterized in filamentous fungi. To better understand the dynamic cellular response to wall perturbation, a-glucan synthase inhibitor (micafungin) was added to a growing A. nidulans shake-flask culture. From this flask, transcriptomic and phosphoproteomic data were acquired over 10 and 120 min, respectively. To differentiate statistically-significant dynamic behavior from noise, a multivariate adaptive regression splines (MARS) model was applied to both data sets. Over 1800 genes were dynamically expressed and over …

Erratum To Armitage And Harris (2020): The Trichoptera Of Panama Xiv. New Species Of Microcaddisflies (Trichoptera: Hydroptilidae) From Omar Torrijos Herrera National Park, Brian J. Armitage, Steven C. Harris

Insecta Mundi

After publication of Armitage and Harris (2020), it was noticed that the wrong illustrations were used for the species Neotrichia espinosa Armitage and Harris (Fig. 9) and Neotrichia michaeli Armitage and Harris (Fig. 10), resulting in images that did not correspond to the captions. The authors and the Insecta Mundi editorial staff apologize for this error. The intended versions of Figures 9 and 10 are reproduced here. Insecta Mundi has also released a revised version of the Armitage and Harris (2020) manuscript, with this error corrected. However, the revised version is not an official peer-reviewed article, and anyone wishing to …

Gutiérrez Of Gutierrezia (Asteraceae: Astereae), Kathleen H. Keeler

Kathleen H. Keeler Publications

Mariano La Gasca y Segura, known as Lagasca, named a southwestern North American plant Gutierrezia without recording who he was honoring. The association of Lagasca with Pedro Gutiérrez Bueno, a leading chemist and pharmacist in Madrid at the same time that LaGasca was director of the Royal Botanical Garden there, makes it likely that Gutiérrez Bueno was the intended honoree.

Assessing Approaches For Stratifying Producer Fields Based On Biophysical Attributes For Regional Yield-Gap Analysis, Spyridon Mourtzinis, Patricio Grassini, Juan I. Rattalino Edreira, José F. Andrade, Peter M. Kyveryga, Shawn P. Conley

Department of Agronomy and Horticulture: Faculty Publications

Large databases containing producer field-level yield and management records can be used to identify causes of yield gaps. A relevant question is how to account for the diverse biophysical background (i.e., climate and soil) across fields and years, which can confound the effect of a given management practice on yield. Here we evaluated two approaches to group producer fields based on biophysical attributes: (i) a technology extrapolation domain spatial framework (‘TEDs’) that delineates regions with similar (long-term average) annual weather and soil water storage capacity and (ii) clusters based on field-specific soil properties and weather during each crop …

Photographic Validation Of Target Versus Nontarget Take Of Brown Treesnake Baits, Shane R. Siers, Aaron B. Shiels, Cynthia G. Payne, Francinem M. Chlarson, Craig S. Clark, Stephen M. Mosher

United States Department of Agriculture Wildlife Services: Staff Publications

Use of toxic baits or other tools for managing nuisance species must ensure that the species of interest is adequately targeted while exposure to nontarget species is minimized. Nontarget takes of acetaminophen‐laced baits for control of invasive brown treesnakes (Boiga irregularis) on Guam may put those animals at risk of lethal intoxication and render the bait unavailable to the intended target species. We used wildlife cameras to identify species removing toxic and nontoxic baits from brown treesnake bait stations designed to exclude nontarget taxa in 2015 and 2016. Throughout various sites and habitat types, and balanced by season (wet vs. …

Time Allocation To Resources By Three Species Of Rats (Rattus Spp.) In A Radial Arm Maze, Gary Witmer, Nathan P. Snow, Rachael S. Moulton

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Introduced rats (Rattus spp.) can pose a serious threat to native flora and fauna, especially on islands where most species have evolved in the absence of terrestrial predators. Effective detection and eradication methods for introduced rats are essential to the maintenance of insular ecosystem integrity. Thus, it is important to better understand the behaviour of rats when they first arrive in a new setting.

Aims. To determine whether rats would find some novel stimuli to be significantly more attractive than other novel stimuli.

Methods. An eight-arm radial maze was used to study the behaviour of three species of Rattus …

Interactions With Humans Shape Coyote Responses To Hazing, Julie K. Young, Edd Hammill, Stewart W. Breck

United States Department of Agriculture Wildlife Services: Staff Publications

Medium and large carnivores coexist with people in urban areas globally, occasionally resulting in

negative interactions that prompt questions about how to reduce human-wildlife conflict. Hazing,

i.e., scaring wildlife, is frequently promoted as an important non-lethal means for urbanites to reduce

conflict but there is limited scientific evidence for its efficacy. We used a population of captive coyotes (Canis latrans) to simulate urban human-coyote interactions and subsequent effects of hazing on coyote behavior. Past experiences with humans significantly affected the number of times a coyoteapproached a human to necessitate hazing. coyotes that had been hand fed by adults had to …

Hawaii As A Microcosm: Advancing The Science And Practice Of Managing Introduced And Invasive Species, Liba Pejchar, Christopher A. Lepczyk, Jean E. Fantle-Lepczyk, Steven C. Hess, M. Tracy Johnson, Christina R. Leopold, Michael Marchetti, Katherine M. Mcclure, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species are a leading driver of global change, with consequences for biodiversity and society. Because of extraordinary rates of endemism, introduction, and extinction, Hawaii offers a rich platform for exploring the cross-disciplinary challenges of managing invasive species in a dynamic world. We highlight key successes and shortcomings to share lessons learned and inspire innovation and action in and beyond the archipelago. We then discuss thematic challenges and opportunities of broad relevance to invaded ecosystems and human communities. Important research needs and possible actions include eradicating mammals from mainland island sanctuaries, assessing hidden threats from poorly known introduced species, harnessing …

Deciphering Interactions Between White-Tailed Deer And Approaching Vehicle, Morgan Pfeiffer, Raymond B. Iglay, Thomas W. Seamans, Bradley F. Blackwell, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Deer-vehicle collisions are a major transportation hazard, but factors affecting deer escape decision-making in response to vehicle approach remain poorly characterized. We made opportunistic observations of deer response to vehicle approach during daylight hours on a restricted- access facility in Ohio, USA (vehicle speeds were ≤64 km/h). We hypothesized that animal proximity to the road, group size, vehicle approach, and ambient conditions would affect perceived risk by white-tailed deer (Odocoileus virginianus) to vehicle approach, as measured by flight-initiation distance (FID). We constructed a priori models for FID, as well as road-crossing behavior. Deer responses were variable and did not demonstrate …

Integrated Unicellular/Filamentous Algal Production, Harvesting And Remediation System, Paul N. Black, James Allen, Timothy J Nicodemus

Department of Biochemistry: Faculty Publications

A method of removing nitrogen-bound nitrate from at least one of groundwater, surface water, or waste water is disclosed. The method includes providing contaminant-containing water from groundwater, surface water, and/or waste water sources. The method further includes adding the contaminant-containing water to an algal photobioreactor system. The method further includes adding an alga culture to the alga photobioreactor system. The method further includes adjusting temperature, CO2 concentration, pH, light wavelength, and/or light intensity in the algal photobioreactor system to optimize the growth of the algea. The method further includes separating the aglae from the water and harvesting algal biomass.

Evaluating Moose Alces Alces Population Response To Infestation Level Of Winter Ticks Dermacentor Albipictus, Daniel D. Ellingwood, Peter J. Pekins, Henry Jones, Anthony R. Musante

United States Department of Agriculture Wildlife Services: Staff Publications

Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) …

Spillover Of Sars-Cov-2 Into Novel Wild Hosts In North America: A Conceptual Model For Perpetuation Of The Pathogen, Alan B. Franklin, Sarah N. Bevins

United States Department of Agriculture Wildlife Services: Staff Publications

There is evidence that the current outbreak of the novel coronavirus SARS-CoV-2, which causes COVID-19, is of animal origin. As with a number of zoonotic pathogens, there is a risk of spillover into novel hosts. Here, we propose a hypothesized conceptual model that illustrates the mechanism whereby the SARS-CoV-2 could spillover from infected humans to naive wildlife hosts in North America. This proposed model is premised on transmission of SARS-CoV-2 from human feces through municipal wastewater treatment plants into the natural aquatic environment where potential wildlife hosts become infected. We use the existing literature on human coronaviruses, including SARS CoV, …

What Is The Limiting Nutrient In Winter In Urban Reservoirs? A Case Study, Precious Nyabami

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The importance of reservoirs in widely acknowledged by urban population, yet little is understood scientifically about their ability to process nutrients deposited into them in winter. Nutrients in waste water, lawns and construction runoff are deposited into reservoirs and several ecosystem services are lost which leads to what several researchers call “the urban syndrome”. Some studies have been done on the winter limnology of lakes, yet little is understood about the same process in reservoirs. To fill this missing knowledge gap, a study on one of Nebraska’s lakes (Holmes’ lake) was done. In this study, we simulated how phosphorus, nitrogen …

Stochastic Simulation Of Cellular Metabolism, Emalie J. Clement, Thomas T. Schulze, Ghada A. Soliman, Beata Joanna Wysocki, Paul H. Davis, Tadeusz A. Wysocki

Department of Electrical and Computer Engineering: Faculty Publications

Increased technological methods have enabled the investigation of biology at nanoscale levels. Such systems require the use of computational methods to comprehend the complex interactions that occur. The dynamics of metabolic systems have been traditionally described utilizing differential equations without fully capturing the heterogeneity of biological systems. Stochastic modeling approaches have recently emerged with the capacity to incorporate the statistical properties of such systems. However, the processing of stochastic algorithms is a computationally intensive task with intrinsic limitations. Alternatively, the queueing theory approach, historically used in the evaluation of telecommunication networks, can significantly reduce the computational power required to generate …

Comparative Analysis Of Viruses In Four Bee Species Collected From Agricultural, Urban, And Natural Landscapes, Tugce Olgun, Sydney Everhart, Troy D. Anderson, Judy Wu-Smart

Department of Entomology: Faculty Publications

Managed honey bees (Apis mellifera L.) and wild bees provide critical ecological services that shape and sustain natural, agricultural, and urban landscapes. In recent years, declines in bee populations have highlighted the importance of the pollination services they provide and the need for more research into the reasons for global bee losses. Several stressors cause declining populations of managed and wild bee species such as habitat degradation, pesticide exposure, and pathogens. Viruses, which have been implicated as a key stressor, are able to infect a wide range of species and can be transmitted both intra- and inter-specifically from infected …

Development Of A Modified Floristic Quality Index As A Rapid Habitat Assessment Method In The Northern Everglades, Rebakah E. Gibble, Donatto D. Surratt

United States National Park Service: Publications

Floristic quality assessments (FQA) using floristic quality indices (FQIs) are useful tools for assessing and comparing vegetation communities and related habitat condition. However, intensive vegetation surveys requiring significant time and technical expertise are necessary, which limits the use of FQIs in environmental monitoring programs. This study modified standard FQI methods to develop a rapid assessment method for characterizing and modeling change in wetland habitat condition in the northern Everglades. Method modifications include limiting vegetation surveys to a subset of taxa selected as indicators of impact and eliminating richness and/or abundance factors from the equation. These modifications reduce the amount of …

First Records Of Alcathoe Carolinensis Engelhardt And Synanthedon Alleri (Engelhardt) In South Carolina, U.S.A., Juang Horng Chong, James D. Young

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Clearwing moths (Lepidoptera: Sesiidae) are day-flying hornet and wasp mimics that can be found visiting flowers for nectar. Larvae bore in the roots, branches and trunks of woody and some herbaceous plants. Some of these larvae are pests in orchards, nurseries and commercial forestry operations. For example, Synanthedon exitiosa (Say) and Synanthedon pictipes (Grote & Robinson) are major pests of peach [Prunus persica (L.) Batsch; Rosaceae] (Johnson et al. 2005), and Synanthedon scitula (Harris) is a major pest of apple (Malus domestica Borkh.; Rosaceae) (Bergh & Leskey 2003). These species, and Podosesia syringae (Harris), Podosesia aureocincta Purrington & …

Medically Defined Infertility Versus Self-Perceived Fertility Problem: Implications Of Survey Wording For Assessing Associations With Depressive Symptoms, Michele H. Lowry, A L. Greil, J Mcquillan, A Burch, K M. Shreffler

Department of Sociology: Faculty Publications

Objective: To examine how measures of infertility based on medical criteria and based on self-perception relate to depressive symptoms among women with infertility. Background: Survey-based studies of depressive symptoms have used either measures of self-reported infertility based on meeting medical criteria or measures of self-perceived fertility problems, but seldom both. It is, therefore, not known which type of measure is more closely associated with depressive symptoms. Materials and Methods: Using ordinary least-squares multiple regression, this study compares associations between a measure of meeting medical criteria for infertility and a measure of self-perceived fertility problems with a common measure of depressive …

Public Perspectives And Media Reporting Of Wolf Reintroduction In Colorado, Rebecca Niemiec, Richard E.W. Berl, Mireille Gonzalez, Tara Teel, Cassiopeia Camara, Matthew Collins, Jonathan Salerno, Kevin Crooks, Courtney Schultz, Stewart Breck, Dana Hoag

United States Department of Agriculture Wildlife Services: Staff Publications

In the state of Colorado, a citizen ballot initiative to reintroduce gray wolves (Canis lupus) is eliciting polarization and conflict among multiple stakeholder and interest groups. Given this complex social landscape, we examined the social context surrounding wolf reintroduction in Colorado as of 2019. We used an online survey of 734 Coloradans representative in terms of age and gender, and we sampled from different regions across the state, to examine public beliefs and attitudes related to wolf reintroduction and various wolf management options. We also conducted a content analysis of media coverage on potential wolf reintroduction in 10 major daily …

Response To White House Office Of Scientific And Technical Policy Request For Information: Public Access To Peer-Reviewed Scholarly Publications, Data And Code Resulting From Federally Funded Research, Paul Royster, Sue Ann Gardner

Copyright, Fair Use, Scholarly Communication, etc.

The current 12-month embargo period is widely disregarded. It is observed by PubMed Central (PMC), but the existence of preprint servers and academic social network sites (ResearchGate or Academia.edu) makes it possible for most authors to distribute peer-reviewed manuscripts at will. While enforcement of the embargo is lax or non-existent, its elimination would have a negative impact on publishers’ cooperation—pushing them to replace so-called “green” open access with author-pays models. The 12-month embargo allows PubMed Central time to prepare accurate and standardized versions of accepted author manuscripts. Requiring immediate access would not eliminate the PMC production time; there would still …

Investigation Of Rapid Diagnostic Tests For Characterization Of Mycobacterium Avium Complex (Mac) From Various Isolates And Identification Of Virulence Factors Of Porcine Reproductive And Respiratory Syndrome Virus (Prrsv) In Vitro, Claudia Antonika

UCARE: Research Products

Chapter 1

Mycobacterium avium complex (MAC) has become one of the major problems in public health and livestock. Members of MAC, such as M. avium subsp paratuberculosis (MAP) and M. avium subsp hominissuis (MAH), are responsible for many opportunistic infections and the loss of livestock. MAP is economically significant to the beef and dairy industries because it is the etiologic agent of Johnes’s disease, a chronic and fatal enteritis in ruminants. Tracing the infection sources of MAC could be difficult since it infects many types of hosts in the natural environment. Furthermore, there is less information known about MAP pathogenicity …

Small Mode Volume Plasmonic Film-Coupled Nanostar Resonators, Negar Charchi, Ying Li, Margaret Huber, Elyahb Allie Kwizera, Xiaohua Huang, Christos Argyropoulos, Thang Hoang

Department of Electrical and Computer Engineering: Faculty Publications

Confining and controlling light in extreme subwavelength scales are tantalizing tasks. In this work, we report a study of individual plasmonic film-coupled nanostar resonators where polarized plasmonic optical modes are trapped in ultrasmall volumes. Individual gold nanostars, separated from a flat gold film by a thin dielectric spacer layer, exhibit a strong light confinement between the sub-10 nm volume of the nanostar's tips and the film. Through dark field scattering measurements of many individual nanostars, a statistical observation of the scattered spectra is obtained and compared with extensive simulation data to reveal the origins of the resonant peaks. We observe …