Stressed out symbiotes:hypotheses for the influence of abiotic stress on arbuscular mycorrhizal fungi

Abiotic stress is a widespread threat to both plant and soil communities. Arbuscular mycorrhizal (AM) fungi can alleviate effects of abiotic stress by improving host plant stress tolerance, but the direct effects of abiotic stress on AM fungi are less well understood. We propose two hypotheses predicting how AM fungi will respond to abiotic stress. The stress exclusion hypothesis predicts that AM fungal abundance and diversity will decrease with persistent abiotic stress. The mycorrhizal stress adaptation hypothesis predicts that AM fungi will evolve in response to abiotic stress to maintain their fitness. We conclude that abiotic stress can have effects on AM fungi independent of the effects on the host plant. AM fungal communities will change in composition in response to abiotic stress, which may mean the loss of important individual species. This could alter feedbacks to the plant community and beyond. AM fungi will adapt to abiotic stress independent of their host plant. The adaptation of AM fungi to abiotic stress should allow the maintenance of the plant-AM fungal mutualism in the face of changing climates. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00442-016-3673-7) contains supplementary material, which is available to authorized users

Reaction of ozone and H2O2 in NH4OH solutions and their reaction with silicon wafers

The main purpose of this study was to evaluate ozone chemistry in NH4OH solutions in terms of oxidizing power compared with H2O2-based NH4OH solutions. The solubility of ozone in the solutions tested was almost nil at room temperature when the solution pH was higher than 9. However, the decrease in solution temperature to 10degreesC resulted in a dissolved ozone concentration at the ppm level in NH4OH solutions. The slow decrease in pH and the increase in redox potential were measured as functions of ozone injection time in NH4OH solutions at 10degreesC. The half-life times of peroxide were 40 min and 4h in 1 : 1 : 5 (volume ratio) NH4OH : H2O2 : H2O (SC1, standard clean 1) solution at 80 and 50degreesC, respectively. However, the half-life of ozone at room temperature was less than 2similar to5 min at the concentrations investigated. The contact angles of bare silicon changed from 72degrees to less than 5degrees within 10 s in SC1 at 80degreesC. In ozonated solutions, change of contact angle to hydrophilic took longer than 3 min depending on the concentration of ozone in NH40H solutions. The addition of peroxide and ozone significantly reduced the etch rate of silicon in NH40H solutions. When Al2O3 particles were deposited on silicon wafers, ozonated NH4OH combined use with megasonic power at room temperature could remove more than over 90% of particles from the wafer surface.X112sciescopu

Multiple detection of food-borne pathogenic bacteria using a novel 16S rDNA-based oligonucleotide signature chip

There have been many attempts to develop sensitive and accurate techniques for the detection and diagnosis of pathogenic bacteria using nucleic acid-based technology. To achieve efficient multiple detection of seven selected food-borne pathogens, we assessed the respective 16S rDNA pathogen specific sequences using an oligonucleotide-based signature array. Strategic optimal design of specific capture probes was achieved by using the characteristic first variable region. To assess the specificity of this pathogen detection system, we employed a two-step experimental strategy. Under conditions established through experiments with chemically synthesized model targets comprising both conserved and variable regions of 16S rDNA, we confirmed the validity of this system using real 16S rDNA targets. Detection with real targets was successfully performed using our system, and better specificity was obtained compared to experiments with model targets. Moreover, the subtypes of Vibrio pathogens were successfully classified. We developed a two-dimensional visualization plot tool for positive control and specific spots, which allowed facile and minute differentiation between spot intensities. Repeated array formats were employed to ensure experimental uniformity, and included the statistical p-value criterion for pathogen discrimination. The present results thus indicate that our novel oligonucleotide-based signature chip detection system can be employed for the effective detection of multiple pathogens. (c) 2006 Elsevier B.V. All rights reserved.X1143sciescopu

Factors influencing insulin sensitivity during hyperinsulinemic-euglycemic clamp in healthy Korean male subjects

Dongseong Shin,1,2 Young Sil Eom, 3,4 Suk Chon,5 Byung-Joon Kim, 3,4 Kyung-Sang Yu,6,* Dae Ho Lee 3,4,*1Department of Pharmacology, Gachon University College of Medicine, Incheon, Korea; 2Clinical Trials Center, Gachon University Gil Medical Center, Incheon, Korea; 3Department of Internal Medicine, Gachon University College of Medicine, Incheon, Korea; 4Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea; 5Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea; 6Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea*These authors contributed equally to this workBackground and objective: The effects of age and related factors on insulin sensitivity have not been definitively evaluated in East Asian populations. We proposed a reference range for the glucose disposal rate (M-value) on hyperinsulinemic-euglycemic study and its association with other parameters.Methods: Healthy, non-diabetic young (n=10) and elderly (n=13) male subjects with normal body mass index were eligible for this study. Subjects who passed the oral glucose tolerance test (OGTT) underwent hyperinsulinemic-euglycemic clamp with high-dose (80 mU/m2·min) insulin infusion.Results: M-values were normalized to body weight (MBW) and fat-free mass (MFFM). Neither M-value was significantly different between age groups (P=0.458 and P=0.900, respectively). An inverse correlation was observed between MFFM and baseline insulin (r=−0.418; P=0.047), baseline C-peptide (r=−0.426; P=0.043) and OGTT 2-hour glucose (r=−0.452; P=0.030). Regarding correlations with other insulin sensitivity indices, M-values were positively associated with the Matsuda index but not with homeostasis model assessment of insulin resistance.Conclusion: Our results suggest that age is not a critical determinant of insulin sensitivity, while fasting insulin and C-peptide levels, OGTT 2-hour glucose level, and Matsuda index are predictable markers of insulin sensitivity in healthy Koreans.Keywords: insulin sensitivity, hyperinsulinemic-euglycemic clamp, glucose disposal rate, age, Matsuda inde