70 results on '"Yee DA"'
Search Results
2. An integrated surface EMG data acquisition system for sports medicine applications
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A. P. Vinod and Chai Yee Da
- Subjects
Engineering ,Signal processing ,medicine.diagnostic_test ,business.industry ,Analog-to-digital converter ,Electromyography ,Signal ,law.invention ,Data acquisition ,law ,Electronic engineering ,medicine ,Waveform ,business ,Signal conditioning ,Energy (signal processing) - Abstract
This paper presents the design and implementation of a PC-based integrated surface electromyogram (SEMG) data acquisition system for the measurement of electrical activity of muscles, efficiency of electrical activity, explosion power (response velocity), and fatigue degree. These parameters are most imperative to physical assessment in sports medicine. The system's hardware consists of four basic units which are detection units, signal conditioning unit, signal processing unit and multi-channel analog to digital converter unit. The graphical user interface displays the EMG signal waveform and extracted parameters. The experiments validated the linear relationship between muscle electrical activity and tension level. Our results show that male subjects are more efficient than female subjects in using lesser energy for a given tension level. However, female subjects exhibited lower explosion power (faster response) than male subjects.
- Published
- 2013
3. The Wnt inhibitory factor 1 restoration in prostate cancer cells was associated with reduced tumor growth, decreased capacity of cell migration and invasion and a reversal of epithelial to mesenchymal transition
- Author
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Xie Jun, Atreya Dash, McQueen Peter, Ghaffar Samia, Guo Yi, Liu Zhongbo, Li Xuesen, Tang Yaxiong, Yee David S, Simoneau Anne R, Hoang Bang H, and Zi Xiaolin
- Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Aberrations in the Wnt pathway have been reported to be involved in the metastasis of prostate cancer (PCa) to bone. We investigated the effect and underlying mechanism of a naturally-occurring Wnt inhibitor, WIF1, on the growth and cellular invasiveness of a bone metastatic PCa cell line, PC3. Results The WIF1 gene promoter was hypermethylated and its expression down-regulated in the majority (7 of 8) of PCa cell lines. Restoration of WIF1 expression in PC-3 cells resulted in a decreased cell motility and invasiveness via up-regulation of epithelial markers (E-cadherin, Keratin-8 and-18), down-regulation of mesenchymal markers (N-cadherin, Fibronectin and Vimentin) and decreased activity of MMP-2 and -9. PC3 cells transfected with WIF1 consistently demonstrated reduced expression of Epithelial-to-Mesenchymal Transition (EMT) transcription factors, Slug and Twist, and a change in morphology from mesenchymal to epithelial. Moreover, WIF1 expression significantly reduced tumor growth by approximately 63% in a xenograft mouse model. This was accompanied by an increased expression of E-cadherin and Keratin-18 and a decreased expression of vimentin in tumor tissues. Conclusion These data suggest that WIF1 regulates tumor invasion through EMT process and thus, may play an important role in controlling metastatic disease in PCa patients. Blocking Wnt signaling in PCa by WIF1 may represent a novel strategy in the future to reduce metastatic disease burden in PCa patients.
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- 2010
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4. Examining treatment strategies for xanthelasma palpebrarum: a comprehensive literature review of contemporary modalities.
- Author
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Yee DA, Zhou AE, and Khachemoune A
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- Humans, Female, Eyelids pathology, Male, Adult, Xanthomatosis therapy, Xanthomatosis diagnosis, Eyelid Diseases therapy, Eyelid Diseases diagnosis, Eyelid Diseases metabolism
- Abstract
Xanthelasma palpebrarum (XP) is the predominant form of cutaneous xanthoma, as it accounts for greater than 95% of cases. It is characterized by the presence of foam cell clusters containing a large amount of low-density lipoprotein (LDL), which are located in the connective tissue of skin, tendons, and fascia. XP lesions commonly present as distinctive yellow-orange macules, papules, or nodules, and are primarily on the upper eyelids as well as the inner canthus. Women are affected twice as often as men, with lesions typically emerging between the ages of 35 and 55. The pathophysiology of XP involves abnormal lipid metabolism and is often associated with hyperlipidemic states like Type II and IV hyperlipidemia, hypothyroidism, weight gain, and fatty diet. Despite the availability of various treatment methods, current XP management lacks standardization, particularly due to limited comparative research. To address this gap, we conducted an extensive literature review of 45 studies published between 2012 to 2023, which provides an updated overview of current XP treatment modalities. This comprehensive analysis will inform researchers and clinicians on the evolving landscape of XP management., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2024
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5. Engineered biosynthesis of plant heteroyohimbine and corynantheine alkaloids in Saccharomyces cerevisiae.
- Author
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Dror MJ, Misa J, Yee DA, Chu AM, Yu RK, Chan BB, Aoyama LS, Chaparala AP, O'Connor SE, and Tang Y
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- Humans, Monoterpenes metabolism, Plants metabolism, Metabolic Engineering, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Secologanin Tryptamine Alkaloids metabolism
- Abstract
Monoterpene indole alkaloids (MIAs) are a class of natural products comprised of thousands of structurally unique bioactive compounds with significant therapeutic values. Due to difficulties associated with isolation from native plant species and organic synthesis of these structurally complex molecules, microbial production of MIAs using engineered hosts are highly desired. In this work, we report the engineering of fully integrated Saccharomyces cerevisiae strains that allow de novo access to strictosidine, the universal precursor to thousands of MIAs at 30-40 mg/L. The optimization efforts were based on a previously reported yeast strain that is engineered to produce high titers of the monoterpene precursor geraniol through compartmentalization of mevalonate pathway in the mitochondria. Our approaches here included the use of CRISPR-dCas9 interference to identify mitochondria diphosphate transporters that negatively impact the titer of the monoterpene, followed by genetic inactivation; the overexpression of transcriptional regulators that increase cellular respiration and mitochondria biogenesis. Strain construction included the strategic integration of genes encoding both MIA biosynthetic and accessory enzymes into the genome under a variety of constitutive and inducible promoters. Following successful de novo production of strictosidine, complex alkaloids belonging to heteroyohimbine and corynantheine families were reconstituted in the host with introduction of additional downstream enzymes. We demonstrate that the serpentine/alstonine pair can be produced at ∼5 mg/L titer, while corynantheidine, the precursor to mitragynine can be produced at ∼1 mg/L titer. Feeding of halogenated tryptamine led to the biosynthesis of analogs of alkaloids in both families. Collectively, our yeast strain represents an excellent starting point to further engineer biosynthetic bottlenecks in this pathway and to access additional MIAs and analogs through microbial fermentation., One Sentence Summary: An Saccharomyces cerevisiae-based microbial platform was developed for the biosynthesis of monoterpene indole alkaloids, including the universal precursor strictosidine and further modified heteroyohimbine and corynantheidine alkaloids., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society of Industrial Microbiology and Biotechnology.)
- Published
- 2024
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6. Competitive interactions with Aedes albopictus alter the nutrient content of Aedes aegypti.
- Author
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Deerman H and Yee DA
- Subjects
- Animals, Ecosystem, Food Chain, Larva, Aedes
- Abstract
Competition is often cited as a central force that affects the distribution and performance of organisms. Ecological stoichiometry is the balance of elements within animal bodies that can be affected by resource acquisition and processing, as well as by intra- or interspecific interactions. Though relatively underexplored for mosquitoes, stoichiometry may provide a wealth of information linking ecological interactions to body nutrient content, and potentially on to pathogen transmission. Detritus, which often varies in nutrient content, forms the base of the food web within the small aquatic habitats occupied by larval mosquitoes, and detrital nutrient content can alter mosquito growth, survival, and population growth. The invasive mosquitoes Aedes albopictus (Diptera: Culicidae) and Aedes aegypti (Diptera: Culicidae) interact as larvae in aquatic systems, often altering their adult populations. Herein, we investigated how different detritus combinations as well as how intra- and interspecific densities of Ae. albopictus and Ae. aegypti would affect coexistence; we also measured how nutrient composition (carbon and nitrogen) and stoichiometry (C:N) of adults would vary with those interactions. Ae. albopictus survival, population growth, and stoichiometry were not affected by intra- or interspecific competition; nutrient values did vary with detritus ratios. However, Ae. aegypti nutrient content and stoichiometry and survival were negatively affected within the lowest nutrient environments in the presence of Ae. albopictus, but in the highest nutrient environments, both species showed high survival rates and population growth. This is the first study to show that adult mosquito body nutrients can be altered by interspecific interactions, and as nutrient content in adults has been linked to pathogen transmission, it provides a novel role of competition in affecting disease dynamics., (© 2023 Royal Entomological Society.)
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- 2023
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7. Non-target effects of methoprene and larvicidal surface films on invertebrate predators of mosquito larvae.
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Nelsen J and Yee DA
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- Animals, Larva physiology, Methoprene pharmacology, Mosquito Control, Insecta, Predatory Behavior, Culicidae physiology
- Abstract
Mosquito larvicides are used across a variety of aquatic habitats, although when applied they likely affect other aquatic organisms. The removal or impairment of top insect predators via larvicides could be beneficial to mosquitoes by allowing their populations to rebound once pesticide levels dissipate. Our goal was to determine if two larvicide types, growth regulators (IGRs) and surface films (SFs), harm non-target aquatic insect communities, and if these chemicals influence the ability of predatory aquatic insects to regulate mosquitoes. We surveyed aquatic sites before and after IGR and SF-application, then compared changes in insect community structure. Evenness was lower in SF treated habitats, and when analyzing prey/controphic taxa only, evenness and diversity changed in untreated reference areas, suggesting that differences measured were due to other environmental factors, not larvicide presence. A field experiment was then conducted by exposing specific predatory aquatic insects to varying doses of IGRs and SFs and then placing them in mesocosms containing mosquito larvae. Surface films were directly lethal to adult dytiscids at recommended and high concentrations. Although we found no significant differences in mosquito emergence among all treatment levels, there was a trend of negative controls (no predator mesocosms) and SF-treated predators allowing the most mosquitoes to emerge compared to positive controls (predators not exposed to larvicides) and IGR-treated predators. Thus, these larvicides may have minimal effects on mosquito larvae predators, but the direct effects of surface films on insects that interact with the water's surface require further investigation.
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- 2023
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8. Plant pollen as a resource affecting the development and survival of the mosquitoes Anopheles quadrimaculatus and Culex quinquefasciatus (Diptera: Culicidae).
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Taka NJ and Yee DA
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- Male, Female, Animals, Larva, Pollen, Culex, Anopheles
- Abstract
Mosquito larvae often subsist on inputs of terrestrial-derived resources, including leaves and dead insects. However, seasonal inputs of plant pollen is an underexplored resource for many species. We compared the effects of three levels (low, medium, high) of two pollen types (corn, pine) on development, mass, and survival in Anopheles quadrimaculatus (Say) and Culex quinquefasciatus (Say) (Diptera: Culcidae). We also examined the nutrient content of adults (%nitrogen, %carbon, C:N) and stable isotopes (δ15N, δ13C). Culex quinquefasciatus had the highest survival rates when grown on high and medium pine pollen compared with low pine. Survival of Culex quinquefasciatus was generally higher compared to that of An. quadrimaculatus on any level of pine, with the latter species having higher survival in high corn. Nutrient content for An. quadrimaculatus did not vary significantly in either pollen type or amount but were more enriched in δ15N in corn pollen relative to pine pollen. For Cx. quinquefasciatus, %N decreased and C:N ratio increased across low to high amounts of corn. Adults raised in corn had generally more δ13C compared to pine pollen. No developmental differences across diets were observed for either species, however both sexes of Cx. quinquefasciatus were generally larger when grown in high pine and medium and high corn pollen compared with other treatments. The poor performance of An. quadrimaculatus on corn pollen was unexpected, however, we show a benefit of corn pollen to Cx. quinquefasciatus with implications for West Nile virus transmission in the United States, especially around agricultural areas where corn is grown., (© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
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9. Genome mining for unknown-unknown natural products.
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Yee DA, Niwa K, Perlatti B, Chen M, Li Y, and Tang Y
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- Dipeptides genetics, Bacteria genetics, Multigene Family, Biosynthetic Pathways genetics, Genome, Bacterial, Biological Products
- Abstract
Genome mining of biosynthetic pathways with no identifiable core enzymes can lead to discovery of the so-called unknown (biosynthetic route)-unknown (molecular structure) natural products. Here we focused on a conserved fungal biosynthetic pathway that lacks a canonical core enzyme and used heterologous expression to identify the associated natural product, a highly modified cyclo-arginine-tyrosine dipeptide. Biochemical characterization of the pathway led to identification of a new arginine-containing cyclodipeptide synthase (RCDPS), which was previously annotated as a hypothetical protein and has no sequence homology to non-ribosomal peptide synthetase or bacterial cyclodipeptide synthase. RCDPS homologs are widely encoded in fungal genomes; other members of this family can synthesize diverse cyclo-arginine-Xaa dipeptides, and characterization of a cyclo-arginine-tryptophan RCDPS showed that the enzyme is aminoacyl-tRNA dependent. Further characterization of the biosynthetic pathway led to discovery of new compounds whose structures would not have been predicted without knowledge of RCDPS function., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)
- Published
- 2023
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10. Ontogenetic Changes in Nutrients and Stoichiometry in the Invasive Mosquito, Aedes albopictus (Diptera: Culicidae).
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Valentine JC and Yee DA
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- Humans, Animals, Larva, Ecology, Diet, Nutrients, Aedes physiology, Culicidae
- Abstract
A variety of physiological, morphological, and behavioral changes occur throughout the life cycle of mosquitoes, which can be correlated with a shift from the aquatic to terrestrial environment. Aedes albopictus Skuse is an abundant invasive species from Asia that was introduced into the Americas in the 1980's and is responsible for transmitting several important human disease-causing pathogens. How physiological and anatomical changes within each instar and throughout the developmental stages are related to changes in carbon (C) and nitrogen (N) levels are an unexplored area of mosquito ecology. We hypothesized that these changes as well as stoichiometry (C:N) would vary with instar stage and larval diet. Cohorts of larvae were grown in three different diets: animal only (crickets), plant only (red maple leaves), and a mixture containing both types. Larval instars (1st-4th), pupae, and adults were raised in each diet and were separately analyzed for nutrient content (%C, %N) and stoichiometry (C:N). Significant changes in nutrient values occurred across the life cycle, with C:N values being lower in early instars versus adults or pupae, especially in animal only or mixed diets; few differences were detected in %C or %N across ontogeny. This knowledge may lead to a better understanding of mosquito ecology and pathogen transmission., (© The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
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11. Mosquito Surveillance for West Nile Virus.
- Author
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Yee DA, Faraji A, and Rochlin I
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- Animals, Female, Humans, Ecosystem, Disease Outbreaks, West Nile virus, Aedes, Culex
- Abstract
Identifying the mosquitoes responsible for transmitting human disease-causing pathogens is of critical importance for effective control of mosquito-borne outbreaks. West Nile virus is often transferred by adult female mosquitoes in the genus Culex, which deposit eggs in a variety of aquatic habitats throughout the world. Herein we describe several methodological approaches to monitor these species in nature, as well as offering details for data collection and analysis., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2023
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12. Structure of the Repurposed Fungal Terpene Cyclase FlvF Implicated in the C-N Bond-Forming Reaction of Flavunoidine Biosynthesis.
- Author
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Tararina MA, Yee DA, Tang Y, and Christianson DW
- Subjects
- Cadaverine, Phylogeny, Terpenes, Type C Phospholipases, Alkyl and Aryl Transferases genetics, Sesquiterpenes metabolism
- Abstract
The fungal species Aspergillus flavus produces an alkaloid terpenoid, flavunoidine, through a hybrid biosynthetic pathway combining both terpene cyclase and nonribosomal peptide synthetase enzymes. Flavunoidine consists of a tetracyclic, oxygenated sesquiterpene core decorated with dimethyl cadaverine and 5,5-dimethyl-l-pipecolate moieties. Unique to the flavunoidine biosynthetic pathway is FlvF, a putative enzyme implicated in stereospecific C-N bond formation as dimethyl cadaverine is linked to the sesquiterpene core to generate pre-flavunoidine. Here, we report the 2.6 Å resolution crystal structure of FlvF, which adopts the α-helical fold of a class I terpene synthase. However, FlvF is not a terpene synthase, as indicated by its lack of enzymatic activity with farnesyl diphosphate and its lack of signature metal ion binding motifs that would coordinate to catalytic Mg
2+ ions. Thus, FlvF is the first example of a protein that adopts a terpene synthase fold but is not a terpene synthase. Two Bis-Tris molecules bind in the active site of FlvF, and the binding of these ligands guided the docking of pre-flavunoidine to generate a model of the enzyme-product complex. Phylogenetic analysis of FlvF and related fungal homologues reveals conservation of residues that interact with the tetracyclic sesquiterpene in this model, but less conservation of residues interacting with the pendant amino moiety. This may hint toward the possibility that alternative amino substrates can be linked to a common sesquiterpene core by FlvF homologues to generate flavunoidine congeners, such as the phospholipase C inhibitor hispidospermidin.- Published
- 2022
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13. Robust network stability of mosquitoes and human pathogens of medical importance.
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Yee DA, Dean Bermond C, Reyes-Torres LJ, Fijman NS, Scavo NA, Nelsen J, and Yee SH
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- Animals, Disease Vectors, Humans, Mosquito Vectors, Culicidae
- Abstract
Background: The exact number of mosquito species relevant to human health is unknown, posing challenges in understanding the scope and breadth of vector-pathogen relationships, and how resilient mosquito vector-pathogen networks are to targeted eradication of vectors., Methods: We performed an extensive literature survey to determine the associations between mosquito species and their associated pathogens of human medical importance. For each vector-pathogen association, we then determined the strength of the associations (i.e., natural infection, lab infection, lab dissemination, lab transmission, known vector). A network analysis was used to identify relationships among all pathogens and vectors. Finally, we examined how elimination of either random or targeted species affected the extinction of pathogens., Results: We found that 88 of 3578 mosquito species (2.5%) are known vectors for 78 human disease-causing pathogens; however, an additional 243 species (6.8%) were identified as potential or likely vectors, bringing the total of all mosquitos implicated in human disease to 331 (9.3%). Network analysis revealed that known vectors and pathogens were compartmentalized, with the removal of six vectors being enough to break the network (i.e., cause a pathogen to have no vector). However, the presence of potential or likely vectors greatly increased redundancies in the network, requiring more than 41 vectors to be eliminated before breaking the network., Conclusion: Although < 10% of mosquitoes are involved in transmitting pathogens that cause human disease, our findings point to inherent robustness in global mosquito vector-pathogen networks., (© 2022. The Author(s).)
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- 2022
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14. Mapping Yellow fever epidemics as a potential indicator of the historical range of Aedes aegypti in the United States.
- Author
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Fijman NS and Yee DA
- Subjects
- Animals, Humans, Mosquito Vectors, United States epidemiology, Aedes, Dengue epidemiology, Epidemics, Yellow Fever epidemiology
- Abstract
Background: Yellow fever (YF) plagued the United States from the 1690s until 1905, resulting in thousands of deaths. Within the US, Aedes aegypti is the only YF vector and almost no data exists for the location of this species prior to the early 1900s., Objectives: To determine the historical range of Ae. aegypti we examined the occurrence of YF epidemics across time and space. We hypothesized that historically Ae. aegypti was driven by human population density, like its contemporary range suggests., Methods: To test this hypothesis, we compiled a list of YF cases in the US, human population density, location, and the number of people infected. This data was mapped using ArcGIS and was analyzed using linear regression models to determine the relationship among variables., Findings: The historic range was generally south of 40º latitude, from Texas in the west to Florida in the east, with concentrations along major waterways like the Mississippi River. Infected individuals and human population density were strongly correlated across the whole dataset as well as by decade., Main Conclusions: Although other factors likely affected the range of Ae. aegypti, we found that human population density was related to the number of people infected with historic YF infections.
- Published
- 2022
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15. Investigating Fungal Biosynthetic Pathways Using Heterologous Gene Expression: Aspergillus nidulans as a Heterologous Host.
- Author
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Yee DA and Tang Y
- Subjects
- Biosynthetic Pathways genetics, Gene Expression, Genes, Fungal, Multigene Family, Aspergillus nidulans genetics, Aspergillus nidulans metabolism, Biological Products metabolism
- Abstract
Fungal natural products encompass an important source of pharmaceutically relevant molecules. Heterologous expression of biosynthetic pathways in chassis strains enables the discovery of new secondary metabolites and characterization of pathway enzymes. In our laboratory, biosynthetic genes in a clustered pathway have been refactored in engineered heterologous hosts such as Aspergillus nidulans. Here we describe the assembly of heterologous expression vectors, transformation into A. nidulans, and detection of new compounds in the transformant strains., (© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2022
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16. Mosquitoes (Diptera: Culicidae) on the islands of Puerto Rico and Vieques, U.S.A.
- Author
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Yee DA, Reyes-Torres LJ, Dean C, Scavo NA, and Zavortink TJ
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- Animals, Arboviruses physiology, Culicidae virology, Larva virology, Puerto Rico, Culicidae classification
- Abstract
We conducted an island-wide survey of the Caribbean islands Puerto Rico and Vieques, U.S.A. during late 2018 and early 2019 to document the current richness of mosquitoes (Diptera: Culicidae). We used a combination of larval surveys and adult trapping using baited CDC light traps and BG-Sentinel traps across 41 of the 78 municipalities. We collected 9 genera, 12 subgenera, and 31 species, which when combined with past studies yields 44 species on the islands. We also note species occurrences across habitat types and elevations from around the islands. One new record, Aedes (Ochlerotatus) obturbator Dyar and Knab, is noted. However we found no evidence of the presence of Aedes albopictus (Skuse), an invasive found throughout the Caribbean, or Aedes (Fredwardsius) vittatus (Bigot), an exotic species recently reported in the Dominican Republic and Cuba. Habitat associations and information regarding the medical importance of species are also included. Given that the islands often experience outbreaks of several arboviruses, obtaining a complete picture of the species present is of high importance., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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17. Tranexamic acid: current use in obstetrics, major orthopedic, and trauma surgery.
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Wong J, George RB, Hanley CM, Saliba C, Yee DA, and Jerath A
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- Blood Loss, Surgical prevention & control, Blood Transfusion, Hemorrhage, Humans, Antifibrinolytic Agents therapeutic use, Obstetrics, Tranexamic Acid therapeutic use
- Abstract
Purpose: In this Continuing Professional Development module, we review the practical pharmacology of tranexamic acid and its clinical use in trauma, obstetrics, and major orthopedic surgery., Principal Findings: Tranexamic acid is a synthetic drug that inhibits fibrinolysis. Multiple clinical trials in various clinical settings have shown that it can reduce blood loss, transfusion rates, and bleeding-associated mortality. In trauma and obstetrical bleeding, early tranexamic acid administration (< three hours) may have greater clinical benefits. Overall, tranexamic acid use appears safe with no significant increase of thromboembolic or seizure events. Nevertheless, current evidence has limitations related to wide heterogeneity in dose, route, and timing of drug administration, as well as generalizability of the large-scale trial findings to higher income nations., Conclusions: Tranexamic acid is an efficacious and safe pharmacological-based blood conservation technique in the management of clinically significant hemorrhage. All anesthesiologists should have a good understanding of the pharmacotherapeutic properties and perioperative role of tranexamic acid therapy both inside and outside of the operating room. The use of tranexamic acid is likely to continue to rise with endorsement by various clinical guidelines and healthcare organizations. Further quantitative research is needed to evaluate optimal dosing and drug efficacy in these clinical scenarios.
- Published
- 2021
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18. Transmission Potential of Zika Virus by Aedes aegypti (Diptera: Culicidae) and Ae. mediovittatus (Diptera: Culicidae) Populations From Puerto Rico.
- Author
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Zimler RA, Yee DA, and Alto BW
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- Animals, Humans, Puerto Rico, Species Specificity, Aedes virology, Mosquito Vectors virology, Zika Virus physiology, Zika Virus Infection transmission
- Abstract
Recurrence of local transmission of Zika virus in Puerto Rico is a major public health risk to the United States, where mosquitoes Aedes aegypti (Linnaeus) and Aedes mediovittatus (Coquillett) are abundant. To determine the extent to which Ae. mediovittatus are capable of transmitting Zika virus and the influence of viremia, we evaluated infection and transmission in Ae. mediovittatus and Ae. aegypti from Puerto Rico using serial dilutions of infectious blood. Higher doses of infectious blood resulted in greater infection rates in both mosquitoes. Aedes aegypti females were up to twice as susceptible to infection than Ae. mediovittatus, indicating a more effective midgut infection barrier in the latter mosquito species. Aedes aegypti exhibited higher disseminated infection (40-95%) than Ae. mediovittatus (<5%), suggesting a substantial midgut escape barrier in Ae. mediovittatus. For Ae. aegypti, transmission rates were low over a range of doses of Zika virus ingested, suggesting substantial salivary gland barriers., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2021
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19. Correction: Quantifying species traits related to oviposition behavior and offspring survival in two important disease vectors.
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Yee DA, Glasgow WC, and Ezeakacha NF
- Abstract
[This corrects the article DOI: 10.1371/journal.pone.0239636.].
- Published
- 2021
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20. No Evidence That Salt Water Ingestion Kills Adult Mosquitoes (Diptera: Culicidae).
- Author
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Yee DA, Dean C, Webb C, Henke JA, Perezchica-Harvey G, White GS, Faraji A, Macaluso JD, and Christofferson R
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- Aedes drug effects, Aedes physiology, Animals, Anopheles drug effects, Anopheles physiology, Culex drug effects, Culex physiology, Diet, Feeding Behavior, Mosquito Control, Water, Culicidae drug effects, Culicidae physiology, Sodium Chloride pharmacology
- Abstract
Various products and insecticides are available that purport to reduce wild populations of adult mosquitoes. Recently, several manufacturers and general public comments on the internet have promoted devices that claim that ingestion of salt will significantly reduce populations of wild mosquitoes to near zero; there are no known scientific efficacy data that support these claims. We tested the survival of nine mosquito species of pest and public health importance across four adult diets: Water Only, Sugar Water Only (8.00%), Salt Water Only (1.03%), and Sugar + Salt Water. Species included the following: Aedes aegypti (L.), Aedes albopictus (Skuse), Aedes dorsalis (Meigen), Aedes notoscriptus (Skuse), Aedes vigilax (Skuse), Anopheles quadrimaculatus (Say), Culex pipiens (L.), Culex quinquefasciatus (Say), and Culex tarsalis (Coquillett). Male and female mosquitoes were placed in cages and allowed to feed on liquid diets under controlled environmental conditions for 1 wk. For seven of the nine species, adult survival was significantly higher in the presence (Sugar Water, Sugar + Salt Water) versus the absence (Water Only, Salt Only) of sugar, with no indication that salt had any effect on survival. Anopheles quadrimaculatus showed intermediate survival in Sugar + Salt to either Sugar Only or no sugar diets, whereas Aedes dorsalis showed low survival in Salt Only versus other diets. Based on our data and coupled with the fact that mosquitoes have physiological and behavioral adaptations that allow them to avoid or process excess salt (as found in blood meals), we conclude that there is no scientific foundation for salt-based control methods of mosquitoes., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America.)
- Published
- 2021
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21. Temporal and Spatial Blood Feeding Patterns of Urban Mosquitoes in the San Juan Metropolitan Area, Puerto Rico.
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Hopken MW, Reyes-Torres LJ, Scavo N, Piaggio AJ, Abdo Z, Taylor D, Pierce J, and Yee DA
- Abstract
Urban ecosystems are a patchwork of habitats that host a broad diversity of animal species. Insects comprise a large portion of urban biodiversity which includes many pest species, including those that transmit pathogens. Mosquitoes (Diptera: Culicidae) inhabit urban environments and rely on sympatric vertebrate species to complete their life cycles, and in this process transmit pathogens to animals and humans. Given that mosquitoes feed upon vertebrates, they can also act as efficient samplers that facilitate detection of vertebrate species that utilize urban ecosystems. In this study, we analyzed DNA extracted from mosquito blood meals collected temporally in multiple neighborhoods of the San Juan Metropolitan Area, Puerto Rico to evaluate the presence of vertebrate fauna. DNA was collected from 604 individual mosquitoes that represented two common urban species, Culex quinquefasciatus ( n = 586) and Aedes aegypti ( n = 18). Culex quinquefasciatus fed on 17 avian taxa (81.2% of blood meals), seven mammalian taxa (17.9%), and one reptilian taxon (0.85%). Domestic chickens dominated these blood meals both temporally and spatially, and no statistically significant shift from birds to mammals was detected. Aedes aegypti blood meals were from a less diverse group, with two avian taxa (11.1%) and three mammalian taxa (88.9%) identified. The blood meals we identified provided a snapshot of the vertebrate community in the San Juan Metropolitan Area and have potential implications for vector-borne pathogen transmission.
- Published
- 2021
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22. Do socioeconomic factors drive Aedes mosquito vectors and their arboviral diseases? A systematic review of dengue, chikungunya, yellow fever, and Zika Virus.
- Author
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Whiteman A, Loaiza JR, Yee DA, Poh KC, Watkins AS, Lucas KJ, Rapp TJ, Kline L, Ahmed A, Chen S, Delmelle E, and Oguzie JU
- Abstract
As the threat of arboviral diseases continues to escalate worldwide, the question of, "What types of human communities are at the greatest risk of infection?" persists as a key gap in the existing knowledge of arboviral diseases transmission dynamics. Here, we comprehensively review the existing literature on the socioeconomic drivers of the most common Aedes mosquito-borne diseases and Aedes mosquito presence/abundance. We reviewed a total of 182 studies on dengue viruses (DENV), chikungunya virus (CHIKV), yellow fever virus (YFVV), Zika virus (ZIKV), and presence of Aedes mosquito vectors. In general, associations between socioeconomic conditions and both Aedes -borne diseases and Aedes mosquitoes are highly variable and often location-specific. Although 50% to 60% of studies found greater presence or prevalence of disease or vectors in areas with lower socioeconomic status, approximately half of the remaining studies found either positive or null associations. We discuss the possible causes of this lack of conclusiveness as well as the implications it holds for future research and prevention efforts., Competing Interests: None. All authors contributed equally to this study., (© 2020 The Authors.)
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- 2020
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23. Quantifying species traits related to oviposition behavior and offspring survival in two important disease vectors.
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Yee DA, Glasgow WC, and Ezeakacha NF
- Subjects
- Aedes physiology, Animals, Culex physiology, Ecosystem, Female, Larva physiology, Species Specificity, Adaptation, Physiological, Behavior, Animal, Mosquito Vectors physiology, Oviposition
- Abstract
Animals with complex life cycles have traits related to oviposition and juvenile survival that can respond to environmental factors in similar or dissimilar ways. We examined the preference-performance hypothesis (PPH), which states that females lacking parental care select juvenile habitats that maximize fitness, for two ubiquitous mosquito species, Aedes albopictus and Culex quinquefasciatus. Specifically, we examined if environmental factors known to affect larval abundance patterns in the field played a role in the PPH for these species. We first identified important environmental factors from a field survey that predicted larvae across different spatial scales. We then performed two experiments, the first testing the independent responses of oviposition and larval survival to these environmental factors, followed by a combined experiment where initial oviposition decisions were allowed to affect larval life history measures. We used path analysis for this last experiment to determine important links among factors in explaining egg numbers, larval mass, development time, and survival. For separate trials, Aedes albopictus displayed congruence between oviposition and larval survival, however C. quinquefasciatus did not. For the combined experiment path analysis suggested neither species completely fit predictions of the PPH, with density dependent effects of initial egg number on juvenile performance in A. albopictus. For these species the consequences of female oviposition choices on larval performance do not appear to fit expectations of the PPH., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
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24. Genome Mining of Alkaloidal Terpenoids from a Hybrid Terpene and Nonribosomal Peptide Biosynthetic Pathway.
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Yee DA, Kakule TB, Cheng W, Chen M, Chong CTY, Hai Y, Hang LF, Hung YS, Liu N, Ohashi M, Okorafor IC, Song Y, Tang M, Zhang Z, and Tang Y
- Subjects
- Ribosomes chemistry, Alkaloids chemistry, Genome, Peptides chemistry, Terpenes chemistry
- Abstract
Biosynthetic pathways containing multiple core enzymes have potential to produce structurally complex natural products. Here we mined a fungal gene cluster that contains two predicted terpene cyclases (TCs) and a nonribosomal peptide synthetase (NRPS). We showed the flv pathway produces flavunoidine 1 , an alkaloidal terpenoid. The core of 1 is a tetracyclic, cage-like, and oxygenated sesquiterpene that is connected to dimethylcadaverine via a C-N bond and is acylated with 5,5-dimethyl-l-pipecolate. The roles of all flv enzymes are established on the basis of metabolite analysis from heterologous expression.
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- 2020
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25. Oviposition Responses and Potential Larval Control Methods of Aedes albopictus (Diptera: Culicidae) in Downspout Extensions.
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Yee DA, Nelsen JA, Deerman JH, Dean CL, Price TL, Rogers RE, and Varnado WC
- Subjects
- Aedes growth & development, Animals, Bacillus thuringiensis chemistry, Female, Insecticides therapeutic use, Larva growth & development, Larva physiology, Mississippi, Aedes physiology, Mosquito Control methods, Oviposition
- Abstract
Aedes albopictus (Skuse) is an important invasive species and vector of several important arboviruses across the globe. This species uses small water-holding cryptic containers as egg laying sites, which pose serious challenges to effective control of adult mosquito populations. Herein, we examined the response of gravid female Ae. albopictus to various features of common downspout extension tubes associated with human dwellings and the effectiveness of control efforts to eliminate larvae. Controlled field trials quantified oviposition in 1) extensions versus rubber bowls meant to mimic other container types, 2) among different shapes and materials of extensions, and 3) among different colors of extensions. We also investigated how flushing and use of Bti larvicides could control larvae. Females were more likely to lay eggs in flat plastic or metal extensions compared to rubber bowls. Eggs were also more plentiful in flat plastic extensions versus either corrugated or metal, and dark brown corrugated extensions had more eggs compared to tan or white. Flushing reduced nearly all larvae when the extensions were properly angled, and applications of Bti pellets or dunks were effective at killing most larvae. We show that dark extensions were preferred over other colors, and that larvae can be effectively removed with minimal effort. However, effective control will likely only come from better education of the public about proper installation of extensions., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2020
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26. Engineered mitochondrial production of monoterpenes in Saccharomyces cerevisiae.
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Yee DA, DeNicola AB, Billingsley JM, Creso JG, Subrahmanyam V, and Tang Y
- Subjects
- Catharanthus enzymology, Catharanthus genetics, Mitochondrial Proteins genetics, Mitochondrial Proteins metabolism, Plant Proteins genetics, Plant Proteins metabolism, Metabolic Engineering, Microorganisms, Genetically-Modified genetics, Microorganisms, Genetically-Modified metabolism, Mitochondria genetics, Mitochondria metabolism, Monoterpenes metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Vinca Alkaloids biosynthesis
- Abstract
Monoterpene indole alkaloids (MIAs) from plants encompass a broad class of structurally complex and medicinally valuable natural products. MIAs are biologically derived from the universal precursor strictosidine. Although the strictosidine biosynthetic pathway has been identified and reconstituted, extensive work is required to optimize production of strictosidine and its precursors in yeast. In this study, we engineered a fully integrated and plasmid-free yeast strain with enhanced production of the monoterpene precursor geraniol. The geraniol biosynthetic pathway was targeted to the mitochondria to protect the GPP pool from consumption by the cytosolic ergosterol pathway. The mitochondrial geraniol producer showed a 6-fold increase in geraniol production compared to cytosolic producing strains. We further engineered the monoterpene-producing strain to synthesize the next intermediates in the strictosidine pathway: 8-hydroxygeraniol and nepetalactol. Integration of geraniol hydroxylase (G8H) from Catharanthus roseus led to essentially quantitative conversion of geraniol to 8-hydroxygeraniol at a titer of 227 mg/L in a fed-batch fermentation. Further introduction of geraniol oxidoreductase (GOR) and iridoid synthase (ISY) from C. roseus and tuning of the relative expression levels resulted in the first de novo nepetalactol production. The strategies developed in this work can facilitate future strain engineering for yeast production of later intermediates in the strictosidine biosynthetic pathway., (Copyright © 2019 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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27. Linking nutrient stoichiometry to Zika virus transmission in a mosquito.
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Paige AS, Bellamy SK, Alto BW, Dean CL, and Yee DA
- Subjects
- Animals, Host-Pathogen Interactions, Humans, Nutrients, Aedes, Zika Virus, Zika Virus Infection
- Abstract
Food quality and quantity serve as the basis for cycling of key chemical elements in trophic interactions; yet the role of nutrient stoichiometry in shaping host-pathogen interactions is under appreciated. Most of the emergent mosquito-borne viruses affecting human health are transmitted by mosquitoes that inhabit container systems during their immature stages, where allochthonous input of detritus serves as the basal nutrients. Quantity and type of detritus (animal and plant) were manipulated in microcosms containing newly hatched Aedes aegypti mosquito larvae. Adult mosquitoes derived from these microcosms were allowed to ingest Zika virus-infected blood and then tested for disseminated infection, transmission, and total nutrients (percent carbon, percent nitrogen, ratio of carbon to nitrogen). Treatments lacking high-quality animal (insect) detritus significantly delayed development. Survivorship to adulthood was closely associated with the amount of insect detritus present. Insect detritus was positively correlated with percent nitrogen, which affected Zika virus infection. Disseminated infection and transmission decreased with increasing insect detritus and percent nitrogen. We provide the first definitive evidence linking nutrient stoichiometry to arbovirus infection and transmission in a mosquito using a model system of invasive Ae. aegypti and emergent Zika virus.
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- 2019
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28. Linking Water Quality to Aedes aegypti and Zika in Flood-Prone Neighborhoods.
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Yee SH, Yee DA, de Jesus Crespo R, Oczkowski A, Bai F, and Friedman S
- Subjects
- Animals, Female, Humans, Male, Mosquito Vectors virology, Population Dynamics, Puerto Rico epidemiology, Residence Characteristics statistics & numerical data, Zika Virus Infection transmission, Aedes virology, Floods, Water Quality, Zika Virus, Zika Virus Infection epidemiology
- Abstract
The ability of ecosystems to regulate water quality and flood events has been linked to health outcomes, including mosquito-borne illnesses. In the San Juan Bay Estuary watershed of Puerto Rico, habitat alterations and land-use development have disrupted watershed hydrology, exacerbating wastewater discharges and subjecting some neighborhoods to frequent flooding events. In 2016, the mosquito-borne illness Zika became a new cause for concern. We hypothesized that nutrient-enriched flood water could provide pulses of supplemental nutrients to local mosquito populations. We conducted a field study in six neighborhoods adjacent to the estuary to assess whether environmental variability of nutrient inputs could be linked to breeding habitat containers, Aedes aegypti larvae and adults, and the acquisition of Zika virus by adult mosquitoes. The most frequently flooded neighborhood had consistently higher levels of nitrogen in estuary water, leaf detritus, containers, and adult mosquitoes compared to other neighborhoods. Adult body nitrogen was significantly related to both nitrogen content of containers and leaf detritus from the local trapping area. Disseminated Zika concentration in adult Ae. aegypti tended to decrease as body carbon and nitrogen increased. Our study provides preliminary evidence that environmental variability in nutrient inputs can influence viral acquisition by mosquito vectors. This suggests that management actions to reduce flooding and improve water quality should go hand-in-hand with more traditional vector control methods, such as aerial spraying, to help control spread of vector-borne diseases.
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- 2019
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29. The role of temperature in affecting carry-over effects and larval competition in the globally invasive mosquito Aedes albopictus.
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Ezeakacha NF and Yee DA
- Subjects
- Animals, Competitive Behavior, Female, Fertility, Larva growth & development, Male, Aedes growth & development, Temperature
- Abstract
Background: Ectotherms, like mosquitoes, have evolved specific responses to variation in environmental conditions like temperature, and these responses could confer a fitness benefit or cost when carried-over to different life stages. However, effects of temperature on animals with complex life-cycles often only focus on part of their life-cycle, or only consider how single aspects of life-history may carry over to new stages. Herein we investigated how temperature affects intraspecific larval competition and carry-over effects from larval to adult stages in the widespread invasive Asian tiger mosquito Aedes albopictus., Methods: For larval competition, larvae were reared at three densities (10, 20, and 40 individuals) across three source temperatures (21 °C, 27 °C and 34 °C). To test carry-over effects, adult survival was measured for individuals crossed with adult temperatures of 21 °C, 27 °C and 34 °C from the larval density of 20 individuals at each source temperature. Fecundity data also were obtained from mated females., Results: For competition, there was a significant interaction between larval density and temperature, with the smallest females, who took the longest to develop, produced in the highest temperatures; density generally accentuated this effect. Regarding carry-over effects, adults exposed to higher temperatures lead to greater differences in fecundity and survival of adult populations., Conclusions: Temperature appears to affect life-history of developing larvae under competitive interactions and can also alter adult fitness as the disparity between larval rearing and adult habitat temperatures increases. This has importance for our understanding for how different life-history stages of Ae. albopictus and other vectors of disease may respond to changing climates.
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- 2019
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30. Response of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Survival, Life History, and Population Growth to Oak Leaf and Acorn Detritus.
- Author
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Rogers RE and Yee DA
- Subjects
- Animals, Female, Population Growth, Tannins analysis, Aedes growth & development, Life History Traits, Quercus chemistry
- Abstract
Aedes albopictus (Skuse) (Diptera: Culicidae) and Aedes aegypti (L.) (Diptera: Culicidae) are invasive container mosquitoes that are of potential medical importance in the southern United States. Seeds (acorns) and leaves from oak trees can contribute seasonally to the detritus of larval container habitats. Herein, we examined the effect of acorns and leaves from the southern live oak (Quercus virginiana Mill.), which has a concomitant range with these mosquitoes, on the population performance of Ae. aegypti and Ae. albopictus. Three levels of acorns and oak leaves were used (0.99, 1.98, and 7.94 g), along with two mixtures (leaf + acorn: 0.50 + 1.48 and 1.48 + 0.50 g). Tannins, secondary plant metabolites that effect herbivory, were measured across all treatment levels; nitrogen and carbon was also measured for detritus and representative females. Survival, female mass, development time, and λ' (per capita rate of population increase) were used to evaluate population performance of both species. Detritus amount but not type led to differences in tannins; however, these differences did not correspond to differences in performance. Acorns had higher carbon and C:N than leaves. Survival for both species was lower in medium amounts of acorns. Female mass varied with leaf amount, whereas development time differed between amounts of pure leaf and acorn. λ' was lowest in medium and high acorns compared with leaves or mixtures. Thus, acorns do appear to limit mosquito survival and affect population growth, suggesting that inputs of this common detritus type may negatively affect container Aedes production., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2019
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31. Papers From a Workshop on Mosquito Ecology and Evolution Inspired by the Career of L. Philip Lounibos.
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Juliano SA, Yee DA, Alto BW, and Reiskind MH
- Subjects
- Animals, History, 20th Century, History, 21st Century, Biological Evolution, Culicidae, Ecology history
- Published
- 2019
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32. Assessing natural infection with Zika virus in the southern house mosquito, Culex quinquefasciatus, during 2016 in Puerto Rico.
- Author
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Yee DA, Dejesus-Crespo R, Hunter FF, and Bai F
- Subjects
- Animals, Puerto Rico, Aedes virology, Culex virology, Mosquito Vectors virology, Zika Virus isolation & purification
- Abstract
The epidemic of Zika in the Western hemisphere has led to intense investigations of all species important in the transmission of Zika virus (ZikV), including putative mosquito vectors. Although evidence points to Stegomyia (= Aedes) (Diptera: Culicidae) mosquitoes as the primary vectors in nature among humans, there remains the possibility that other common mosquito species may be implicated in the rapid spread of the virus. Herein, field-caught Culex quinquefasciatus (Diptera: Culicidae) collected during June 2016 in different neighbourhoods in San Juan, Puerto Rico were examined for the presence of natural infection with ZikV. Stegomyia aegypti (= Aedes aegypti) from the same locations were also analysed. None of the Cx. quinquefasciatus tested showed natural infection for ZikV, whereas S. aegypti tested positive at seven sites. The present results suggest that Cx. quinquefasciatus was not involved in the transmission of ZikV in San Juan, Puerto Rico in 2016., (© 2017 The Royal Entomological Society.)
- Published
- 2018
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33. A Statewide Survey for Container-Breeding Mosquitoes in Mississippi.
- Author
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Goddard J, Moraru GM, Mcinnis SJ, Portugal JS, Yee DA, Deerman JH, and Varnado WC
- Subjects
- Aedes physiology, Animals, Culicidae growth & development, Introduced Species, Larva growth & development, Larva physiology, Mississippi, Animal Distribution, Culicidae physiology
- Abstract
Container-breeding mosquitoes are important in public health due to outbreaks of Zika, chikungunya, and dengue viruses. This paper documents the distribution of container-breeding mosquito species in Mississippi, with special emphasis on the genus Aedes. Five sites in each of the 82 Mississippi counties were sampled monthly between May 1 and August 31, 2016, and 50,109 mosquitoes in 14 species were collected. The most prevalent and widely distributed species found was Ae. albopictus, being found in all 82 counties, especially during July. A recent invasive, Ae. japonicus, seems to be spreading rapidly in Mississippi since first being discovered in the state in 2011. The most abundant Culex species collected were Cx. quinquefasciatus (found statewide), Cx. salinarius (almost exclusively in the southern portion of the state), and Cx. restuans (mostly central and southern Mississippi). Another relatively recent invasive species, Cx. coronator, was found in 20 counties, predominantly in the southern one-third of the state during late summer. Co-occurrence data of mosquito species found in the artificial containers were also documented and analyzed. Lastly, even though we sampled extensively in 410 sites across Mississippi, no larval Ae. aegypti were found. These data represent the first modern statewide survey of container species in Mississippi, and as such, allows for better public health readiness for emerging diseases and design of more effective vector control programs.
- Published
- 2017
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34. Oviposition preference and offspring performance in container breeding mosquitoes: evaluating the effects of organic compounds and laboratory colonisation.
- Author
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Allgood DW and Yee DA
- Abstract
The preference-performance hypothesis predicts that organisms lacking parental care should oviposit in habitats that optimize offspring performance. We investigated preference-performance relationships for the Asian tiger mosquito ( Aedes albopictus Skuse) and the southern house mosquito ( Culex quinquefasciatus Say) (Diptera:Culicidae), two medically important container-breeding species, in response to an organic chemical blend mimicking decaying plant matter. Additionally, we evaluated the effects of long-term laboratory colonization of Cx. quinquefasciatus by using wild and laboratory strains.Oviposition bioassays were conducted by releasing gravid mosquitoes into field enclosures with automobile tires containing low and high concentrations of the chemical blend, and water controls. The offspring were then reared in water collected from the tires in which they were deposited. Aedes albopictus and wild Cx. quinquefasciatus laid more eggs in the chemical blend than water controls but did not differentiate between the low and high concentrations. Conversely, laboratory Cx. quinquefasciatus only preferred the high concentration to the low concentration. No statistical associations between oviposition preference and larval survival were found, as the chemical blend did not affect survivorship of either species.The oviposition preference for the chemical blend over water controls suggests that both species oviposit in the best available resource environment, but further studies are needed before conclusions regarding preference-performance relationships can be drawn.We found that long-term laboratory colonization affects oviposition behavior in Cx. quinquefasciatus , suggesting that behavioral studies on laboratory strains are not always applicable to wild populations., Competing Interests: Conflict of Interest The authors of this manuscript have no conflict of interest to declare. There are no disputes over the ownership of the data presented in this manuscript. All who contributed to this work are credited in the ‘Acknowledgments’ and ‘Contribution of Authors’ sections.
- Published
- 2017
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35. What Can Larval Ecology Tell Us About the Success of Aedes albopictus (Diptera: Culicidae) Within the United States?
- Author
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Yee DA
- Subjects
- Aedes growth & development, Animals, Introduced Species, Larva growth & development, Larva physiology, Population Dynamics, United States, Aedes physiology, Environment
- Abstract
Aedes albopictus (Skuse) was introduced in the United States approximately 30 years ago, and since has become an important pest and vector of disease. This species uses small water-holding containers as sites for oviposition and larval development. Larvae can consume a wide range of detritus-based energy sources, including microorganisms, and as such the type and quantity of detritus that enters these systems have been studied for the effects on adult populations. This review examines the documented responses of Ae. albopictus to different larval environments within the United States, and some of its unique ecology that may lead to a better understanding of its spread and success. Field surveys generally find larvae in shaded containers with high amounts of organic detritus. Larvae have higher survival and population growth under high amounts of detritus and microorganisms, but they also can outcompete other species when nutrients are limiting. Allocation of time to feeding by larvae is greater and more focused compared with resident species. These latter two points also may explain differences in carbon and nitrogen composition (nutrient stoichiometry), which point to a lower need for nitrogen. Combined, these facts suggest that the Ae. albopictus is a species with a relatively wide niche that had been able to exploit container habitats in the United States better than resident species. After 30 yr of research, only a narrow range of detritus types and environmental conditions have been examined. Data on factors affecting the production of adults and its spread and apparent success are still needed., (© The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2016
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36. Thirty Years of Aedes albopictus (Diptera: Culicidae) in America: An Introduction to Current Perspectives and Future Challenges.
- Author
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Yee DA
- Subjects
- Americas, Animals, Aedes, Mosquito Vectors
- Published
- 2016
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37. Correction: How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus.
- Author
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Yee DA, Kaufman MG, and Ezeakacha NF
- Published
- 2016
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38. Interspecific Interactions Between Adult Aedes albopictus and Culex quinquefasciatus (Diptera: Culicidae).
- Author
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Daniels S, Ezeakacha NF, and Yee DA
- Subjects
- Animals, Ecosystem, Longevity, Aedes, Competitive Behavior, Culex, Oviposition
- Abstract
Single and mixed species densities of adult Aedes albopictus and Culex quinquefasciatus were manipulated to determine if different combinations affected their egg laying preference or mortality rates. Oviposition was measured in environments that contained containers of different surface areas (small cups vs. larger bowls), and the number of eggs (Aedes) and egg rafts or larvae (Culex) deposited by each species was examined with respect to intra- and interspecific density treatment levels. Mixed species densities did not have an effect on survivorship, but single species densities did affect longevity, with higher densities leading to shorter life spans in Cx. quinquefasciatus: Cx. quinquefasciatus lived longer than Ae. albopictus overall. There was no significant effect of density combinations on oviposition patterns in either species, but Cx. quinquefasciatus laid more rafts in bowls compared with cups. There is little evidence of adult interactions between these species; however, future experimental work is necessary to more fully characterize the possible effects of adult interactions on these species.
- Published
- 2016
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39. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus.
- Author
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Yee DA, Kaufman MG, and Ezeakacha NF
- Subjects
- Aedes anatomy & histology, Aedes growth & development, Animal Nutritional Physiological Phenomena, Animals, Carbon analysis, Carbon metabolism, Culex anatomy & histology, Culex growth & development, Environment, Female, Food Chain, Male, Nitrogen analysis, Nitrogen metabolism, Sex Characteristics, Aedes physiology, Culex physiology
- Abstract
Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container species under similar detrital environments, and if supported may assist in explaining the production of vector populations in nature.
- Published
- 2015
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40. Mosquito Larvae in Tires from Mississippi, United States: The Efficacy of Abiotic and Biotic Parameters in Predicting Spatial and Temporal Patterns of Mosquito Populations and Communities.
- Author
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Yee DA, Abuzeineh AA, Ezeakacha NF, Schelble SS, Glasgow WC, Flanagan SD, Skiff JJ, Reeves A, and Kuehn K
- Subjects
- Animals, Culicidae growth & development, Geography, Larva growth & development, Larva physiology, Longevity, Mississippi, Population Dynamics, Species Specificity, Time Factors, Animal Distribution, Culicidae physiology, Environment
- Abstract
Container systems, including discarded vehicle tires, which support populations of mosquitoes, have been of interest for understanding the variables that produce biting adults that serve as both nuisances and as public health threats. We sampled tires in six sites at three times in 2012 across the state of Mississippi to understand the biotic and abiotic variables responsible for explaining patterns of larvae of common species, species richness, and total abundance of mosquitoes. From 498 tires sampled, we collected >58,000 immatures representing 16 species, with the most common species including Aedes albopictus (Skuse), Culex quinquefasciatus (L.), Orthopodomyia signifera (Coquillett), Aedes triseriatus (Say), Toxorhynchites rutilus septentrionalis (Coquillett), and Culex territans (Walker) accounting for ∼97% of all larvae. We also documented 32 new county records for resident species and recent arrivals in the state, including Aedes japonicus japonicus (Theobald) and Culex coronator (Dyar & Knab). Cluster analysis, which was used to associate sites and time periods based on similar mosquito composition, did reveal patterns across the state; however, there also were more general patterns between species and genera and environmental factors. Broadly, Aedes was often associated with factors related to detritus, whereas Culex was frequently associated with habitat variables (e.g., tire size and water volume) and microorganisms. Some Culex did lack factors connecting variation in early and late instars, suggesting differences between environmental determinants of oviposition and survival. General patterns between the tire environment and mosquito larvae do appear to exist, especially at the generic level, and point to inherent differences between genera that may aid in predicting vector locations and populations., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2015
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41. Influence of resource levels, organic compounds and laboratory colonization on interspecific competition between the Asian tiger mosquito Aedes albopictus (Stegomyia albopicta) and the southern house mosquito Culex quinquefasciatus.
- Author
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Allgood DW and Yee DA
- Subjects
- Aedes drug effects, Aedes growth & development, Animals, Animals, Laboratory growth & development, Animals, Laboratory physiology, Competitive Behavior drug effects, Culex drug effects, Culex growth & development, Female, Larva physiology, Longevity, Male, Organic Chemicals pharmacology, Population Growth, Aedes physiology, Culex physiology
- Abstract
The mosquitoes Aedes albopictus (Stegomyia albopicta) (Skuse) and Culex quinquefasciatus (Say) (Diptera: Culicidae) are common inhabitants of tyres and other artificial containers, which constitute important peridomestic mosquito breeding habitats. We tested the hypotheses that interspecific resource competition between the larvae of these species is asymmetrical, that the concentration of chemicals associated with decomposing detritus affects the competitive outcomes of these species, and that wild and colonized strains of Cx. quinquefasciatus are affected differently by competition with Ae. albopictus. We conducted two laboratory competition experiments wherein we measured survivorship and estimated population growth (λ') in both species under multiple mixed-species densities. Under varying resource levels, competition was asymmetrical: Ae. albopictus caused competitive reductions or exclusions of Cx. quinquefasciatus under conditions of limited resources. In a second experiment, which used both wild and colonized strains of Cx. quinquefasciatus, organic chemical compounds associated with decomposing detritus did not affect the competitive outcome. The colonized strain of Cx. quinquefasciatus had greater survivorship and adult mass, and faster development times than the wild strain, but both strains were similarly affected by competition with Ae. albopictus. Competition between these species may have important consequences for vector population dynamics, especially in areas in which tyres and artificial containers constitute the majority of mosquito breeding habitats., (© 2014 The Royal Entomological Society.)
- Published
- 2014
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42. Behavioral differences among four co-occurring species of container mosquito larvae: effects of depth and resource environments.
- Author
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Skiff JJ and Yee DA
- Subjects
- Animals, Environment, Larva, Species Specificity, Aedes, Culex, Feeding Behavior
- Abstract
Mosquito larvae often exhibit different behaviors depending on the aspects of the aquatic environment, including the presence of different physical factors and detrital food sources. Regardless of these physical differences, different genera also devote different amounts of time to different behaviors. To determine if differences existed among four focal mosquito species (Aedes albopictus (Singh), Aedes triseriatus (Say), Culex quinquefasciatus (Say), Culex coronator Dyar & Knab), we recorded behaviors under different food environments (animal detritus, leaf detritus, and inoculum + inert material) and depths (shallow and deep). Based on past work, we predicted that larval mosquitoes in the genus Culex would spend more time filtering or resting at the surface of containers, whereas Aedes mosquitoes would spend more time browsing on surfaces. Behaviors were recorded for 30 min and were used to generate instantaneous scan census of behavior (thrashing, browsing, and resting or filtering) and locations (top, middle, bottom, wall, and detritus) of each larva every minute. There were significant differences in behaviors among the three detritus types and the four species (Culex generally different than Aedes), as well as a significant interaction between depth and detritus type. Consistent with predictions, Culex species spent more time filtering or resting, whereas Aedes larvae spent more time browsing on detritus. However, all four species changed their behavior similarly among the different environments, and Cx. coronator exhibited some similar behaviors as the two Aedes species. These behavioral differences may aid in explaining performance differences between different species and outcomes of interspecific encounters, which in turn can affect adult emergence and patterns of disease.
- Published
- 2014
- Full Text
- View/download PDF
43. Observation of improved adherence with frequent urine drug testing in patients with pain.
- Author
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Yee DA, Hughes MM, Guo AY, Barakat NH, Tse SA, Ma JD, Best BM, and Atayee RS
- Subjects
- Analgesics, Opioid urine, Buprenorphine therapeutic use, Buprenorphine urine, Chronic Pain urine, Fentanyl therapeutic use, Fentanyl urine, Humans, Hydrocodone therapeutic use, Hydrocodone urine, Methadone therapeutic use, Methadone urine, Morphine therapeutic use, Morphine urine, Oxycodone therapeutic use, Oxycodone urine, Analgesics, Opioid therapeutic use, Chronic Pain drug therapy, Medication Adherence
- Abstract
Objective: To determine the relationship between urine drug testing (UDT) frequency and patient adherence for prescribed buprenorphine, carisoprodol, fentanyl, hydrocodone, methadone, morphine, and oxycodone., Setting: Patients with pain routinely seen by private practitioners., Design: A retrospective analysis was conducted on urinary excretion data analyzed by Millennium Laboratories between March 2008 and May 2011., Patient Participants: Patients in the United States with chronic pain who underwent routine UDT to confirm adherence for prescribed medications., Interventions: Adherence for the urine drug test was defined as the presence of parent drug and/or metabolite(s) greater than or equal to the lower limit of quantitation. The percent of adherence for prescribed medications was compared to the average percent of the same in subjects with five or more visits., Main Outcomes: Correlation analyses were used to determine the relationship between adherence for prescribed medications and number of visits., Results: There were 255,168 specimens submitted for testing from 166,755 individuals. When monitoring with more frequent visits (≥5 visits) adherence was higher by 1 percent for buprenorphine (89 percent vs 88 percent); 8 percent for carisoprodol (77 percent vs 69 percent); 5 percent for fentanyl (95 percent vs 90 percent); 7 percent for hydrocodone (83 percent vs 76 percent); 3 percent for methadone (96 percent vs 93 percent); 5 percent for morphine (92 percent vs 87 percent); and 8 percent for oxycodone (90 percent vs 82 percent)., Conclusions: Adherence for prescribed medications is higher with frequent urine monitoring. UDT can be used as tool that may help improve this in patients with chronic pain.
- Published
- 2014
- Full Text
- View/download PDF
44. Implications of saline concentrations for the performance and competitive interactions of the mosquitoes Aedes aegypti (Stegomyia aegypti) and Aedes albopictus (Stegomyia albopictus).
- Author
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Yee DA, Himel E, Reiskind MH, and Vamosi SM
- Subjects
- Aedes drug effects, Aedes growth & development, Animals, Competitive Behavior drug effects, Florida, Larva drug effects, Ovum drug effects, Population Growth, Pupa drug effects, Sodium Chloride pharmacology, Species Specificity, Aedes physiology, Salt Tolerance physiology
- Abstract
Aedes albopictus (Stegomyia albopictus) (Diptera: Culicidae) has probably supplanted Aedes aegypti (Stegomyia aegypti) throughout most of its historical range in the U.S.A., although Ae. aegypti still exists in large coastal cities in southern Florida. We measured salt concentrations in field containers along an axis perpendicular to the coast and examined intraspecific outcomes in these species under different salt concentrations in a factorial study using varying intra- and interspecific densities in different conditions of salinity to order to determine if salt could mitigate the documented competitive superiority of Ae. albopictus. Salt in field containers declined away from the coast, with maximal values similar to our lower salt concentrations. Egg hatching and short-term survival of pupae and late instars were not affected by salt concentrations; survival of early instars of both species decreased at higher concentrations. In high salt conditions, Ae. aegypti achieved higher survival. In the longterm experiment, both species displayed longer development times. Salt did not affect interactions for either species; Ae. aegypti survived in the highest salt conditions, regardless of density. The tolerance of Ae. aegypti to high salt concentrations may allow it to use coastal containers, although because salt did not mediate interspecific interactions between Ae. aegypti and Ae. albopictus, the ultimate effects of salt on the coexistence of these species or exclusion of either species remain unknown., (© 2013 The Royal Entomological Society.)
- Published
- 2014
- Full Text
- View/download PDF
45. Observations on the urine metabolic profile of codeine in pain patients.
- Author
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Yee DA, Atayee RS, Best BM, and Ma JD
- Subjects
- Analgesics, Opioid adverse effects, Analgesics, Opioid pharmacokinetics, Biotransformation, Codeine adverse effects, Codeine pharmacokinetics, Cytochrome P-450 CYP2D6 metabolism, Cytochrome P-450 CYP2D6 Inhibitors, Drug Interactions, Enzyme Inhibitors therapeutic use, Humans, Hydrocodone urine, Hydromorphone urine, Pain diagnosis, Pain urine, Retrospective Studies, Risk Assessment, Risk Factors, Urinalysis, Analgesics, Opioid therapeutic use, Analgesics, Opioid urine, Codeine therapeutic use, Codeine urine, Drug Monitoring methods, Pain drug therapy
- Abstract
This retrospective data analysis explored the relationship between codeine and its metabolites morphine, hydrocodone and hydromorphone. The objectives were: (i) to determine urine concentrations and mole fractions of codeine and metabolites and (ii) to examine the effect of cytochrome P450 (CYP) 2D6 inhibition on metabolite mole fractions. De-identified urine specimens were collected between September 2010 and July 2011 and analyzed using LC-MS-MS to determine codeine, morphine, hydrocodone and hydromorphone concentrations. Geometric mean urine concentrations were 0.833, 0.085 and 0.055 for morphine, hydrocodone and hydromorphone, respectively. Mole fractions were 0.23, 0.025 and 0.014 for morphine, hydrocodone and hydromorphone, respectively. The fraction of excreted codeine in the urine increased (slope = 0.06 ± .01, R² = 0.02) with total moles. As the total amount of codeine and metabolites increased, the fraction of codeine increased, while the fraction of active metabolites decreased. CYP2D6 inhibition with paroxetine, fluoxetine, bupropion and methadone significantly decreased the fraction of morphine excreted. The prevalence of codeine metabolism to morphine was considerably higher than codeine to hydrocodone. The urine concentration of codeine excreted was the greatest, followed by morphine and hydrocodone. Subjects should be monitored during concomitant use of codeine and CYP2D6 inhibitors as this affects the amount of morphine metabolite formation.
- Published
- 2014
- Full Text
- View/download PDF
46. Interspecific competition of a new invasive mosquito, Culex coronator, and two container mosquitoes, Aedes albopictus and Cx. quinquefasciatus (Diptera: Culicidae), across different detritus environments.
- Author
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Yee DA and Skiff JF
- Subjects
- Animals, Environment, Female, Male, Aedes growth & development, Competitive Behavior, Culex growth & development, Introduced Species
- Abstract
The mosquito Culex coronator (Dyar and Knab) (Diptera: Culicidae) has undergone rapid range expansion in the United States since 2003, with its historical distribution in the southwest expanding eastward to the Atlantic coast. Although Cx. coronator nominally use small natural aquatic habitats for development, the use of containers (e.g., tires) makes it potentially important as container invasive. To determine the potential ecological effects of Cx. coronator on resident container species, we conducted a laboratory experiment to assess its competitive ability with two common tire-inhabiting species, Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) (Diptera: Culicidae). Larvae were reared under a factorial design with each species alone and in combination (Cx. coronator + Ae. albopictus, Cx. coronator + Cx. quinquefasciatus) across three different resource environments (leaf detritus only, animal detritus only, animal + leaf). Mosquito performance (survival, adult male and female mass, and development time) was measured for each species across treatments. Female Cx. coronator developed slowest when grown with Ae. albopictus, or when grown with leaves only regardless of species combinations; similar patterns emerged for males although species effects were restricted to mass. Few differences were evident in performance for male and female Cx. coronator across detritus environments when grown with Cx. quinquefasciatus. Cx. quinquefasciatus did not vary in mass or development time in the presence of Cx. coronator compared with when grown alone. Ae. albopictus female mass was 15% lower in the presence of Cx. coronator. Survival of Cx. coronator was highest in animal and leaf detritus containers, although survival was generally lower when larvae were grown with Ae. albopictus. These findings suggest that the performance of Cx. coronator is similar to that of Cx. quinquefasciatus but it suffers in the presence of Ae. albopictus under some resource environments.
- Published
- 2014
- Full Text
- View/download PDF
47. Seasonal photoperiods alter developmental time and mass of an invasive mosquito, Aedes albopictus (Diptera: Culicidae), across its north-south range in the United States.
- Author
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Yee DA, Juliano SA, and Vamosi SM
- Subjects
- Animals, Female, Larva growth & development, Male, Seasons, United States, Adaptation, Biological, Aedes growth & development, Introduced Species, Photoperiod
- Abstract
The Asian tiger mosquito, Aedes albopictus (Skuse), is perhaps the most successful invasive mosquito species in contemporary history. In the United States, Ae. albopictus has spread from its introduction point in southern Texas to as far north as New Jersey (i.e., a span of approximately 14 degrees latitude). This species experiences seasonal constraints in activity because of cold temperatures in winter in the northern United States, but is active year-round in the south. We performed a laboratory experiment to examine how life-history traits of Ae. albopictus from four populations (New Jersey [39.4 degrees N], Virginia [38.6 degrees N], North Carolina [35.8 degrees N], Florida [27.6 degrees N]) responded to photoperiod conditions that mimic approaching winter in the north (short static daylength, short diminishing daylength) or relatively benign summer conditions in the south (long daylength), at low and high larval densities. Individuals from northern locations were predicted to exhibit reduced development times and to emerge smaller as adults under short daylength, but be larger and take longer to develop under long daylength. Life-history traits of southern populations were predicted to show less plasticity in response to daylength because of low probability of seasonal mortality in those areas. Males and females responded strongly to photoperiod regardless of geographic location, being generally larger but taking longer to develop under the long daylength compared with short day lengths; adults of both sexes were smaller when reared at low larval densities. Adults also differed in mass and development time among locations, although this effect was independent of density and photoperiod in females but interacted with density in males. Differences between male and female mass and development times was greater in the long photoperiod suggesting differences between the sexes in their reaction to different photoperiods. This work suggests that Ae. albopictus exhibits sex-specific phenotypic plasticity in life-history traits matching variation in important environmental variables.
- Published
- 2012
- Full Text
- View/download PDF
48. Concurrent effects of resource pulse amount, type, and frequency on community and population properties of consumers in detritus-based systems.
- Author
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Yee DA and Juliano SA
- Subjects
- Animal Nutritional Physiological Phenomena, Animals, Ecosystem, Food Chain, Plant Leaves, Population Density, Population Dynamics, Regression Analysis, Trees, Biota, Invertebrates physiology
- Abstract
Episodic resource inputs (i.e., pulses) can affect food web properties and community dynamics, but detailed mechanistic understanding of such effects remain elusive. Natural aquatic microsystems (e.g., tree holes, human-made containers) are colonized by invertebrates that form complex food webs dependent on episodic and sometimes sizeable inputs of allochthonous detritus from adjacent terrestrial environments. We investigated how variation in pulse frequency, amount, and resource type interacted to affect richness, abundance, composition, and population sizes of colonizing invertebrates in water-filled tires and tree hole analogs in a forest habitat. Different container types were used to assess the generality of effects across two environmental contexts. Containers received large infrequent or small frequent pulses of animal or leaf detritus of different cumulative amounts distributed over the same period. Invertebrates were sampled in June and September when cumulative detritus input was equal for the two pulse frequencies. Pulse frequency and detritus type interacted to affect the responses of richness and abundance in both months; pulse frequency alone in June affected the relationship between richness and abundance. Richness and abundance were also greater with more detritus regardless of detritus type. One group, the filter feeders, were most important in driving the response of abundance and richness to pulses, especially in June. This work highlights the potential complex nature of responses of communities and populations to resource pulses and implicates the ability of certain groups to exploit pulses of detrital resources as a key to understanding community-level responses to pulses.
- Published
- 2012
- Full Text
- View/download PDF
49. Observations on the urine metabolic ratio of oxymorphone to oxycodone in pain patients.
- Author
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Yee DA, Best BM, Atayee RS, and Pesce AJ
- Subjects
- Analgesics, Opioid pharmacokinetics, Analgesics, Opioid therapeutic use, Chromatography, High Pressure Liquid, Humans, Models, Biological, Oxycodone pharmacokinetics, Oxycodone therapeutic use, Pain drug therapy, Reference Values, Reproducibility of Results, Retrospective Studies, Tandem Mass Spectrometry, Time Factors, Analgesics, Opioid urine, Oxycodone urine, Oxymorphone urine, Pain urine
- Abstract
The object of this study was to evaluate the metabolism of oxycodone to oxymorphone in a pain patient population using a quantitative liquid chromatography-tandem mass spectrometry analysis of 32,656 urine specimens obtained from pain patients between March 2008 and Feb 2010. The observed excretion was modeled using logarithmic transformation and approximated a Gaussian distribution. Oxycodone excretion into urine had a geometric mean of 1.93 mg/g of creatinine and oxymorphone had a value of 0.41 mg/g of creatinine. Increasing concentrations of oxycodone correlated with a smaller proportion of oxymorphone excretion suggesting saturation of oxycodone metabolism. Urine samples containing oxycodone without oxymorphone allowed an estimation of the proportion of poor metabolizers (2.4 ± 2.1%) in the population. A similar analysis of samples containing oxymorphone without oxycodone gave an estimate of the proportion of ultra-rapid metabolizers (1.8 ± 1.1%) in the population. Samples with concentrations of oxycodone above 10 mg/g of creatinine showed a sub-population of subjects with metabolic ratios roughly 100-fold less than the linear predictive model in this study. This study describes typical ranges for oxycodone and oxymorphone in urine, and showed that it is possible to identify fast or slow metabolizers who may be at risk for adverse events.
- Published
- 2012
- Full Text
- View/download PDF
50. Constitutive differences between natural and artificial container mosquito habitats: vector communities, resources, microorganisms, and habitat parameters.
- Author
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Yee DA, Allgood D, Kneitel JM, and Kuehn KA
- Subjects
- Animals, Aedes, Culex, Ecosystem, Water Microbiology
- Abstract
Aquatic containers, including tree holes and vehicle tires, harbor a diverse assemblage of mosquitoes capable of vectoring important diseases. Many studies have examined containers as a mosquito breeding site, although no data exist that have simultaneously compared mosquito communities between tree holes and tires, and few have quantified differences in environmental factors or food resources that may be important for explaining population or community differences. At two times (early and late summer 2009) we sampled two tire and two tree hole sites in south-central Mississippi, and for each container we enumerated mosquito larvae and measured several environmental parameters (canopy cover, water volume, and detritus), and biomass and productivity of fungi and bacteria, and species richness and abundance of protozoans. Tree holes held less water but were more shaded compared with tires; however, after correcting for volume differences, tree holes contained more detritus and were higher in some microorganism measures (protozoan richness, bacterial productivity in the water column). Based on community dissimilarity analysis of mosquitoes, strong differences existed between container types and sampling period; Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) were dominant in tires, whereas Ae. triseriatus (Say) and Orthopodomyia signifera (Coquillett) were dominant in tree holes. This study also reports the use of tires by the invasive mosquito Cx. coronator (Dyar and Knab). Tree holes supported a higher density of larvae but fewer species than tires, though there was variation across time. Our work illustrates that detrital inputs and some microorganisms differ in fundamental ways between tires and tree holes, and because of compositional differences in mosquito communities, these small aquatic habitats cannot be considered to be homogeneous mosquito habitats.
- Published
- 2012
- Full Text
- View/download PDF
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