Method Development for Monitoring Bean Leaf Beetle, \u3ci\u3eCerotoma trifurcata\u3c/i\u3e (Forster) (Coleoptera: Chrysomelidae), Susceptibility to Thiamethoxam Seed Treatments on Soybeans

The increased use of thiamethoxam seed treatments for controlling pests such as the bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), suggests the need for methods to measure and monitor the development of resistance to thiamethoxam. The objectives of this study were to develop a bioassay method that can be used to monitor bean leaf beetle susceptibility to thiamethoxam, and to quantify the relative concentrations of thiamethoxam and clothianidin in early growth stage soybean tissue treated with thiamethoxam as a seed treatment. Overwintered and F1 bean leaf beetles were collected from alfalfa and soybean fields and used in excised soybean leaf laboratory bioassays to measure susceptibility to thiamethoxam. Petioles of excised leaves were immersed in 0, 10, 50, 100, 500 and 1000 ng a.i./ml thiamethoxam solutions, beetles were placed on the leaves, and beetle mortality and defoliation levels were recorded. The bioassaymethod proved adequate to calculate an LC50 and LC90, and an EC50 based on defoliation level. The quantification of insecticide residues in soybean leaves from different vegetative stages indicates that the thiamethoxam concentration declines rapidly as the plant grows, and concentrations are at lethal levels for bean leaf beetles through V2. These results provide a method for monitoring bean leaf beetle susceptibility to thiamethoxam that is more representative of the pathway of exposure encountered by beetles in the field, particularly with respect to seed treatments, and provides an estimate of baseline susceptibility for future thiamethoxam resistance monitoring efforts

Co-occurrence of the Cyanotoxins BMAA, DABA and Anatoxin-a in Nebraska Reservoirs, Fish, and Aquatic Plants

Several groups of microorganisms are capable of producing toxins in aquatic environments. Cyanobacteria are prevalent blue green algae in freshwater systems, and many species produce cyanotoxins which include a variety of chemical irritants, hepatotoxins and neurotoxins. Production and occurrence of potent neurotoxic cyanotoxins β-N-methylamino-L-alanine (BMAA), 2,4-diaminobutyric acid dihydrochloride (DABA), and anatoxin-a are especially critical with environmental implications to public and animal health. Biomagnification, though not well understood in aquatic systems, is potentially relevant to both human and animal health effects. Because little is known regarding their presence in fresh water, we investigated the occurrence and potential for bioaccumulation of cyanotoxins in several Nebraska reservoirs. Collection and analysis of 387 environmental and biological samples (water, fish, and aquatic plant) provided a snapshot of their occurrence. A sensitive detection method was developed using solid phase extraction (SPE) in combination with high pressure liquid chromatography-fluorescence detection (HPLC/FD) with confirmation by liquid chromatography-tandem mass spectrometry (LC/MS/MS). HPLC/FD detection limits ranged from 5 to 7 μg/L and LC/MS/MS detection limits were \u3c0.5 μg/L, while detection limits for biological samples were in the range of 0.8–3.2 ng/g depending on the matrix. Based on these methods, measurable levels of these neurotoxic compounds were detected in approximately 25% of the samples, with detections of BMAA in about 18.1%, DABA in 17.1%, and anatoxin-a in 11.9%

Population Health Metrics During the Early Stages of the COVID-19 Pandemic: Correlative Pilot Study

Background: COVID-19 has caused nearly 1 million deaths in the United States, not to mention job losses, business and school closures, stay-at-home orders, and mask mandates. Many people have suffered increased anxiety and depression since the pandemic began. Not only have mental health symptoms become more prevalent, but alcohol consumption has also increased during this time. Helplines offer important insight into both physical and mental wellness of a population by offering immediate, anonymous, cheap, and accessible resources for health and substance use disorders (SUD) that was unobstructed by many of the mandates of the pandemic. Further, the pandemic also launched the use of wastewater surveillance, which has the potential for tracking not only population infections but also consumption of substances such as alcohol. Objective: This study assessed the feasibility of using multiple public surveillance metrics, such as helpline calls, COVID-19 cases, and alcohol metabolites in wastewater, to better understand the need for interventions or public health programs in the time of a public health emergency. Methods: Ethanol metabolites were analyzed from wastewater collected twice weekly from September 29 to December 4, 2020, in a Midwestern state. Calls made to the helpline regarding housing, health care, and mental health/SUD were correlated with ethanol metabolites analyzed from wastewater samples, as well as the number of COVID-19 cases during the sampling period. Results: Correlations were observed between COVID-19 cases and helpline calls regarding housing and health care needs. No correlation was observed between the number of COVID-19 cases and mental health/SUD calls. COVID-19 cases on Tuesdays were correlated with the alcohol metabolite ethyl glucuronide (EtG). Finally, EtG levels were negatively associated with mental health/SUD helpline calls. Conclusions: Although helpline calls provided critical services for health care and housing-related concerns early in the pandemic, evidence suggests helpline calls for mental health/SUD-related concerns were unrelated to COVID-19 metrics. Instead, COVID metrics were associated with alcohol metabolites in wastewater. Although this research was formative, with continued and expanded monitoring of population metrics, such as helpline usage, COVID-19 metrics, and wastewater, strategies can be implemented to create precision programs to address the needs of the population

Herbicide Loading to Shallow Ground Water beneath Nebraska’s Management Systems Evaluation Area

Better management practices can counter deterioration of ground water quality. From 1991 through 1996 the influence of improved irrigation practices on ground water pesticide contamination was assessed at the Nebraska Management SystemsEvaluation Area. Three 13.4-ha corn (Zea mays L.) fields were studied: a conventional furrow-irrigated field, a surge-irrigated field and a center pivot–irrigated field, and a center pivot–irrigated alfalfa (Medicago sativa L.) field. The corn fields received one identical banded application of Bicep (atrazine [6-chloro-N-ethyl-N’-(1-methylethyl)-1,3,5-triazine-2,4,-diamine] _ metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide]) annually; the alfalfa field was untreated. Ground water samples were collected three times annually from 16 depths of 31 multi-level samplers. Six years of sample data indicated that a greater than 50% reduction in irrigation water on the corn management fields lowered average atrazine concentrations in the upper 1.5 m of the aquifer downgradient of the corn fields from approximately 5.5 to –1. Increases in deethylatrazine (DEA; 2-chloro-4-amino-6-isopropyl- amino-s-triazine) to atrazine molar ratios indicated that reducing water applications enhanced microbial degradation of atrazine in soil zones. The occurrence of peak herbicide loading in ground water was unpredictable but usually was associated with heavy precipitation within days of herbicide application. Focused recharge of storm runoff that ponded in the surge-irrigated field drainage ditch, in the upgradient road ditch, and at the downgradient end of the conventionally irrigated field was a major mechanism for vertical transport. Sprinkler irrigation technology limited areas for focused recharge and promoted significantly more soil microbial degradation of atrazine than furrow irrigation techniques and, thereby, improved ground water quality

Regulation of vascular smooth muscle cell expression and function of matrix metalloproteinases is mediated by estrogen and progesterone exposure

ObjectivePostmenopausal women receiving hormone replacement therapy (HRT) have been reported to have more adverse outcomes after vascular reconstructions, including increased intimal hyperplasia development and bypass graft failure. HRT may be affecting the pathway contributing to intimal hyperplasia. An important component of this pathway involves matrix metalloproteinases (MMPs), implicated in vascular remodeling due to their ability to degrade components of the extracellular matrix. We hypothesize that estrogen (Est) and progesterone (Prog) upregulate the MMP pathway in vascular smooth muscle cells (VSMCs) thereby increasing MMP activity and function.Methods and ResultsVSMCs were incubated with Est (5 ng/mL), Prog (50 ng/mL), Est + Prog combination (Est/Prog), and/or doxycycline (40 μg/mL; Doxy). Using reverse transcriptase polymerase chain reaction (RT-PCR) analysis we have previously shown membrane type 1-MMP (MT1-MMP) messenger ribonucleic acid (mRNA) levels are significantly increased by Est. Here, Western blot analyses indicated MT1-MMP and MMP-2 protein levels, not tissue inhibitor of MMP-2 (TIMP-2), were increased in response to Est and Est/Prog (P < .05 vs control). In-gel zymography revealed that Est and Est/Prog resulted in increased MMP-2 activity (hormone groups, P < .05 vs control) with no significant difference among the hormone groups. VSMC migration was increased by 45 ± 14% in response to Est (P < .05 vs control), as measured using a modified Boyden chamber assay. Doxycycline significantly inhibited basal and Est/Prog-stimulated increases in MMP-2 activity (P < .05 vs control; P < .05 vs hormone groups), and partially blocked basal and hormonally stimulated migration (P < .05 vs control and Est).ConclusionEstrogen and progesterone affects the MMP pathway by increasing MMP-2 enzymatic activity, possibly via the upregulation of MT1-MMP expression without a corresponding increase in TIMP expression. This increased collagenase activity increases VSMC motility and their ability to migrate through a collagen type IV lattice. Est/Prog upregulation of MT1-MMP may contribute to the adverse effect of HRT on vascular interventions.Clinical RelevancePostmenopausal women receiving HRT have more adverse outcomes after vascular reconstructions, including intimal hyperplasia, restenosis, and decreased graft patency. MMPs play a major role in vascular remodeling due to their degradation of components of the basement membrane separating vascular cell layers. Specifically, MMP-2 has a strong affinity for collagen type IV degradation, and MT1-MMP is a transmembrane protein known to activate MMP-2 by proteolytic cleavage. Here we provide strong evidence for MT1-MMP's role in increased MMP-2 activity and increased cellular migration in VSMCs exposed to estrogen and progesterone. Manipulations of the MMP pathway specifically targeting MT1-MMP expression at the time of vascular interventions may improve outcomes in females receiving HRT

Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments

A total of 43 papers published in 2014 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to measuring and predicting biological effects for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, natural and synthetics steroids, and antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Occurrence and Fate, Antibiotic Resistance Genes, and Risk Assessment

Microarray-Based Analysis of Differential Gene Expression between Infective and Noninfective Larvae of Strongyloides stercoralis

Strongyloides stercoralis is a soil-transmitted helminth that affects an estimated 30–100 million people worldwide. Chronically infected persons who are exposed to corticosteroids can develop disseminated disease, which carries a high mortality (87–100%) if untreated. Despite this, little is known about the fundamental biology of this parasite, including the features that enable infection. We developed the first DNA microarray for this parasite and used it to compare infective third-stage larvae (L3i) with non-infective first stage larvae (L1). Using this method, we identified 935 differentially expressed genes. Functional characterization of these genes revealed L3i biased expression of heat shock proteins and genes with products that have previously been shown to be immunoreactive in infected humans. Genes putatively involved in transcription were found to have L1 biased expression. Potential chemotherapeutic and vaccine targets such as far-1, ucr 2.1 and hsp-90 were identified for further study

The significance of genome-wide transcriptional regulation in the evolution of stress tolerance.

It is widely recognized that stress plays an important role in directing the adaptive adjustment of an organism to changing environments. However, very little is known about the evolution of mechanisms that promote stress-induced variation. Adaptive transcriptional responses have been implicated in the evolution of tolerance to natural and anthropogenic stressors in the environment. Recent technological advances in transcriptomics provide a mechanistic understanding of biological pathways or processes involved in stress-induced phenotypic change. Furthermore, these studies are (semi) quantitative and provide insight into the reaction norms of identified target genes in response to specific stressors. We argue that plasticity in gene expression reaction norms may be important in the evolution of stress tolerance and adaptation to environmental stress. This review highlights the consequences of transcriptional plasticity of stress responses within a single generation and concludes that gene promoters containing a TATA box are more capable of rapid and variable responses than TATA-less genes. In addition, the consequences of plastic transcriptional responses to stress over multiple generations are discussed. Based on examples from the literature, we show that constitutive over expression of specific stress response genes results in stress adapted phenotypes. However, organisms with an innate capacity to buffer stress display plastic transcriptional responses. Finally, we call for an improved integration of the concept of phenotypic plasticity with studies that focus on the regulation of transcription. © Springer Science+Business Media B.V. 2010