185 research outputs found

    Survey of Subterranean Termite (Isoptera: Rhinotermitidae) Utilization of Temperate Forests

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    Both native and invasive subterranean termites (Isoptera: Rhinotermitidae), including the Formosan subterranean termite, are well known pests of urban areas, but little is known about their distribution or impact in forest ecosystems of the southeastern United States. Recently harvested timber stumps were mechanically inspected for the presence of subterranean termites in multiple locations across southern Mississippi and eastern Louisiana. A systematic line plot cruise with 100 x 200m spacing and1/20thha plots was implemented, and all stumps with a diameter greater than 7.6cm were inspected. In total, 7,413 stumps were inspected for the presence of subterranean termites, and 406 of those contained native subterranean termite (Reticulitermes spp) infestations. Light traps were also placed at 8 sites to detect the presence of subterranean termite alates. While no invasive Formosan subterranean termites were found during mechanical inspection of tree stumps, alates were captured in light traps at three sites. The proportion of stumps infested with subterranean termites was negatively correlated with the number of stumps in each plot. Although 6.27% of pine stumps and 1.86% of hardwood stumps were infested, no correlation was found between subterranean termite presence and type of stump (pine or hardwood). Infestations of stumps by subterranean termites ranged from 0.94% to 14.97% depending on site

    Surface Free Energy of Blue-Stained Southern Pine Sapwood from Bark Beetle-Attacked Trees

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    Blue-stained wood cut from bark beetle-attacked southern pine has a lower economic value than unstained wood. Wood composite products containing blue-stained wood may offer an opportunity to recover some lost timber value. This study investigated the surface-free energy of blue-stained wood. Southern pine sapwood samples with and without blue stain from both green and kiln-dried sources were obtained. Dynamic contact angle analyses were performed using three probe liquids: ethylene glycol, formamide, and deionized water. Surface-free energy was determined by applying the geometric mean model using two-liquid pairs with deionized water. The polar forces were higher across all wood types and in water-ethylene glycol vs water-formamide. Surface-free energy of air-dried blue-stained sapwood was lower than all other wood types. However, kiln-dried blue-stained sapwood had a higher surface-free energy than all other wood types. These results were indicative of a tree's wound response to bark beetle attack, the volatilization of naturally occurring hydrocarbons in southern pine sapwood, and the resulting increase in wood permeability caused by blue-stained fungal colonization across the sapwood. However, improvements in wetting observed for kiln-dried blue-stained sapwood may lead to cost and quality issues in wood composite manufacturing associated with overdrying and overpenetration of an adhesive

    Technical Note: The Susceptibility of Chemically Treated Southern Hardwoods to Subterranean Termite Attack

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    Ongoing research into chemically treating southern hardwoods for producing structural composite lumber suggests that some improvements may be imparted by modifying the wood. How chemical treatment(s) affect modified wood durability, particularly resistance to Reticulitermes flavipes, was the objective of this study. Water-saturated samples of yellow-poplar, sweetgum, and red oak were heated at 150°C for 30 min in two solutions: water and 1.0% NaOH; controls were also included. Samples were subjected to the AWPA E1-09 no-choice termite test in which mass loss from R. flavipes was determined. The species and treatments independently and significantly affected the mass loss. Yellow-poplar, which had the lowest specific gravity, averaged significantly greater mass loss than sweetgum and red oak for all three exposures. All species treated in water or NaOH showed a higher degree of termite degradation as compared with the controls

    Technical Note: The Susceptibility of Chemically Treated Southern Hardwoods to Subterranean Termite Attack

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    Ongoing research into chemically treating southern hardwoods for producing structural composite lumber suggests that some improvements may be imparted by modifying the wood. How chemical treatment(s) affect modified wood durability, particularly resistance to Reticulitermes flavipes, was the objective of this study. Water-saturated samples of yellow-poplar, sweetgum, and red oak were heated at 150°C for 30 min in two solutions: water and 1.0% NaOH; controls were also included. Samples were subjected to the AWPA E1-09 no-choice termite test in which mass loss from R. flavipes was determined. The species and treatments independently and significantly affected the mass loss. Yellow-poplar, which had the lowest specific gravity, averaged significantly greater mass loss than sweetgum and red oak for all three exposures. All species treated in water or NaOH showed a higher degree of termite degradation as compared with the controls

    Use of a biochar-based formulation for coating corn seeds

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    The series of experiments summarized here were conducted with the objective to evaluate the benefits of using biochar for coating corn seeds. Seeds coated with a slurry containing bio-based ingredients and biochar were tested for germination and vigor, and for their potential to being infected by the fungus Aspergillus flavus, using a novel single seed incubator specifically designed for these purposes. Biochar-treated seeds were also planted for two years in experimental fields in the Mississippi Delta to evaluate their effect on corn yield and aflatoxin contamination of kernels. Experiments were conducted with two types of commercial biochar; one was obtained from hardwood residues and the other from coconut shells. Application of both types of biochar for coating the seeds did not affect seed germination and vigor. However, treated seeds showed increased wettability and a more rapid water uptake. This resulted in a 8.5% shortening of germination time. Microbiological analysis using plate culturing and qPCR methods showed that biochar was not conducive to the growth of A. flavus. This was also confirmed by analyzing soil samples that were collected from experimental fields located in the Mississippi Delta. Most importantly, although aflatoxin contamination was different in the two experimental years, aflatoxin contamination of corn kernels was not affected by biochar-based formulations

    Effect of Aging on A1C Levels in Individuals Without Diabetes: Evidence from the Framingham Offspring Study and the National Health and Nutrition Examination Survey 2001–2004

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    OBJECTIVE—Although glycemic levels are known to rise with normal aging, the nondiabetic A1C range is not age specific. We examined whether A1C was associated with age in nondiabetic subjects and in subjects with normal glucose tolerance (NGT) in two population-based cohorts

    Adaptation In the Sensory Cortex Drives Bistable Switching During Auditory Stream Segregation

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    Current theories of perception emphasize the role of neural adaptation, inhibitory competition, and noise as key components that lead to switches in perception. Supporting evidence comes from neurophysiological findings of specific neural signatures in modality-specific and supramodal brain areas that appear to be critical to switches in perception. We used functional magnetic resonance imaging to study brain activity around the time of switches in perception while participants listened to a bistable auditory stream segregation stimulus, which can be heard as one integrated stream of tones or two segregated streams of tones. The auditory thalamus showed more activity around the time of a switch from segregated to integrated compared to time periods of stable perception of integrated; in contrast, the rostral anterior cingulate cortex and the inferior parietal lobule showed more activity around the time of a switch from integrated to segregated compared to time periods of stable perception of segregated streams, consistent with prior findings of asymmetries in brain activity depending on the switch direction. In sound-responsive areas in the auditory cortex, neural activity increased in strength preceding switches in perception and declined in strength over time following switches in perception. Such dynamics in the auditory cortex are consistent with the role of adaptation proposed by computational models of visual and auditory bistable switching, whereby the strength of neural activity decreases following a switch in perception, which eventually destabilizes the current percept enough to lead to a switch to an alternative percept

    Resetting of Auditory and Visual Segregation Occurs After Transient Stimuli of the Same Modality

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    In the presence of a continually changing sensory environment, maintaining stable but flexible awareness is paramount, and requires continual organization of information. Determining which stimulus features belong together, and which are separate is therefore one of the primary tasks of the sensory systems. Unknown is whether there is a global or sensory-specific mechanism that regulates the final perceptual outcome of this streaming process. To test the extent of modality independence in perceptual control, an auditory streaming experiment, and a visual moving-plaid experiment were performed. Both were designed to evoke alternating perception of an integrated or segregated percept. In both experiments, transient auditory and visual distractor stimuli were presented in separate blocks, such that the distractors did not overlap in frequency or space with the streaming or plaid stimuli, respectively, thus preventing peripheral interference. When a distractor was presented in the opposite modality as the bistable stimulus (visual distractors during auditory streaming or auditory distractors during visual streaming), the probability of percept switching was not significantly different than when no distractor was presented. Conversely, significant differences in switch probability were observed following within-modality distractors, but only when the pre-distractor percept was segregated. Due to the modality-specificity of the distractor-induced resetting, the results suggest that conscious perception is at least partially controlled by modality-specific processing. The fact that the distractors did not have peripheral overlap with the bistable stimuli indicates that the perceptual reset is due to interference at a locus in which stimuli of different frequencies and spatial locations are integrated

    Quinoa phenotyping methodologies: An international consensus

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    Quinoa is a crop originating in the Andes but grown more widely and with the genetic potential for significant further expansion. Due to the phenotypic plasticity of quinoa, varieties need to be assessed across years and multiple locations. To improve comparability among field trials across the globe and to facilitate collaborations, components of the trials need to be kept consistent, including the type and methods of data collected. Here, an internationally open-access framework for phenotyping a wide range of quinoa features is proposed to facilitate the systematic agronomic, physiological and genetic characterization of quinoa for crop adaptation and improvement. Mature plant phenotyping is a central aspect of this paper, including detailed descriptions and the provision of phenotyping cards to facilitate consistency in data collection. High-throughput methods for multi-temporal phenotyping based on remote sensing technologies are described. Tools for higher-throughput post-harvest phenotyping of seeds are presented. A guideline for approaching quinoa field trials including the collection of environmental data and designing layouts with statistical robustness is suggested. To move towards developing resources for quinoa in line with major cereal crops, a database was created. The Quinoa Germinate Platform will serve as a central repository of data for quinoa researchers globally.Fil: Stanschewski, Clara S.. King Abdullah University of Science and Technology; Arabia SauditaFil: Rey, Elodie. King Abdullah University of Science and Technology; Arabia SauditaFil: Fiene, Gabriele. King Abdullah University of Science and Technology; Arabia SauditaFil: Craine, Evan B.. Washington State University; Estados UnidosFil: Wellman, Gordon. King Abdullah University of Science and Technology; Arabia SauditaFil: Melino, Vanessa J.. King Abdullah University of Science and Technology; Arabia SauditaFil: Patiranage, Dilan S. R.. King Abdullah University of Science and Technology; Arabia SauditaFil: Johansen, Kasper. King Abdullah University of Science and Technology; Arabia SauditaFil: Schmöckel, Sandra M.. King Abdullah University of Science and Technology; Arabia SauditaFil: Bertero, Hector Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Producción Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Oakey, Helena. University of Adelaide; AustraliaFil: Colque Little, Carla. Universidad de Copenhagen; DinamarcaFil: Afzal, Irfan. University of Agriculture; PakistánFil: Raubach, Sebastian. The James Hutton Institute; Reino UnidoFil: Miller, Nathan. University of Wisconsin; Estados UnidosFil: Streich, Jared. Oak Ridge National Laboratory; Estados UnidosFil: Amby, Daniel Buchvaldt. Universidad de Copenhagen; DinamarcaFil: Emrani, Nazgol. Christian-albrechts-universität Zu Kiel; AlemaniaFil: Warmington, Mark. Agriculture And Food; AustraliaFil: Mousa, Magdi A. A.. Assiut University; Arabia Saudita. King Abdullah University of Science and Technology; Arabia SauditaFil: Wu, David. Shanxi Jiaqi Agri-Tech Co.; ChinaFil: Jacobson, Daniel. Oak Ridge National Laboratory; Estados UnidosFil: Andreasen, Christian. Universidad de Copenhagen; DinamarcaFil: Jung, Christian. Christian-albrechts-universität Zu Kiel; AlemaniaFil: Murphy, Kevin. Washington State University; Estados UnidosFil: Bazile, Didier. Savoirs, Environnement, Sociétés; Francia. Universite Paul-valery Montpellier Iii; FranciaFil: Tester, Mark. King Abdullah University of Science and Technology; Arabia Saudit
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