3,624 research outputs found
Functional analysis of the acetic acid resistance (aar) gene cluster in Acetobacter aceti strain 1023
Vinegar production requires acetic acid bacteria that produce, tolerate, and conserve high levels of acetic acid. When ethanol is depleted, aerobic acetate overoxidation to carbon dioxide ensues. The resulting diauxic growth pattern has two logarithmic growth phases, the first associated with ethanol oxidation and the second associated with acetate overoxidation. The vinegar factory isolate Acetobacter aceti strain 1023 has a long intermediate stationary phase that persists at elevated acetic acid levels. Strain 1023 conserves acetic acid despite possessing a complete set of citric acid cycle (CAC) enzymes, including succinyl-CoA:acetate CoA-transferase (SCACT), the product of the acetic acid resistance (aar) gene aarC. In this study, cell growth and acid production were correlated with the functional expression of aargenes using reverse transcription-polymerase chain reaction, Western blotting, and enzyme activity assays. Citrate synthase (AarA) and SCACT (AarC) were abundant in A. aceti strain 1023 during both log phases, suggesting the transition to acetate overoxidation was not a simple consequence of CAC enzyme induction. A mutagenized derivative of strain 1023 lacking functional AarC readily oxidized ethanol but was unable to overoxidize acetate, indicating that the CAC is required for acetate overoxidation but not ethanol oxidation. The primary role of the aar genes in the metabolically streamlined industrial strain A. aceti 1023 appears to be to harvest energy via acetate overoxidation in otherwise depleted medium
Anomalous U(1), holomorphy, supersymmetry breaking and dilaton stabilization
We argue that in certain models with family symmetries the implementation of
the alignment mechanism for the supression of the flavor changing neutral
currents requires mass matrices with holomorphic zeros in the down quark
sector. Holomorphic zeros typically open flat directions that potentially spoil
the uniqueness of the supersymmetric vacuum. We then present an anomalous U(1)
model without holomorphic zeros in the quark sector that can reproduce the
fermion mass hierarchies, provided that is of order one. To avoid
undesired flavor changing neutral currents we propose a supersymmetry breaking
mechanism and a dilaton stabilization scenario that result in degenerate
squarks at and a calculable low energy spectrum. We present the
numerical predictions of this model for the Higgs mass for different values of
and .Comment: 14 pages, no figures; wording of the abstract is change
Metal stopping reagents facilitate discontinuous activity assays of the de novo purine biosynthesis enzyme PurE
The conversion of 5-aminoimidazole ribonucleotide (AIR) to 4-carboxy-AIR (CAIR) represents an unusual divergence in purine biosynthesis: microbes and nonmetazoan eukaryotes use class I PurEs while animals use class II PurEs. Class I PurEs are therefore a potential antimicrobial target; however, no enzyme activity assay is suitable for high throughput screening (HTS). Here we report a simple chemical quench that fixes the PurE substrate/product ratio for 24 h, as assessed by the Bratton-Marshall assay (BMA) for diazotizable amines. The ZnSO4 stopping reagent is proposed to chelate CAIR, enabling delayed analysis of this acid-labile product by BMA or other HTS method
Antioxidant responses and NRF2 in synergistic developmental toxicity of PAHs in zebrafish
Author Posting. © The Authors, 2009. This is the author's version of the work. It is posted here by permission of Oxford University Press for personal use, not for redistribution. The definitive version was published in Toxicological Sciences 109 (2009): 217-227, doi:10.1093/toxsci/kfp038.Early piscine life-stages are sensitive to polycyclic aromatic hydrocarbon (PAH) exposure,
which can cause pericardial effusion and craniofacial malformations. We previously reported that
certain combinations of PAHs cause synergistic developmental toxicity, as observed with co-exposure
to the aryl hydrocarbon receptor (AHR) agonist β-naphthoflavone (BNF) and cytochrome P4501A
inhibitor α-naphthoflavone (ANF). Herein, we hypothesized that oxidative stress is a component of
this toxicity. We examined induction of antioxidant genes in zebrafish embryos (Danio rerio)
exposed to BNF or ANF individually, a BNF+ANF combination, and a pro-oxidant positive control,
tert-butylhydroperoxide (tBOOH). We measured total glutathione, and attempted to modulate
deformities using the glutathione synthesis inhibitor buthionine sulfoxamine (BSO) and increase
glutathione pools with N-acetyl cysteine (NAC). In addition, we used a morpholino to knockdown
expression of the antioxidant response element transcription factor NRF2 to determine if this would
alter gene expression or increase deformity severity. BNF+ANF co-exposure significantly increased
expressions of superoxide dismutase1 and2, glutathione peroxidase 1, pi class glutathione-s-transferase,
and glutamate cysteine-ligase to a greater extent than tBOOH, BNF, or ANF alone. BSO
pretreatment decreased some glutathione levels, but did not worsen deformities, nor did NAC
diminish toxicity. Knockdown of NRF2 increased mortality following tBOOH challenge, prevented
significant upregulation of antioxidant genes following both tBOOH and BNF+ANF exposures, and
exacerbated BNF+ANF‐related deformities. Collectively, these findings demonstrate that antioxidant
responses are a component of PAH synergistic developmental toxicity, and that NRF2 is protective
against prooxidant and PAH challenges during development.This work was supported by the National Institute for Environmental Health Sciencessupported
Duke University Superfund Basic Research Program (P42 ES10356), National Institute for
Environmental Health Sciences‐supported Duke University Integrated Toxicology & Environmental
Health Program (TS ES07031), United States Environmental Protection Agency STAR fellowship (to
A.T.‐L.), Duke University RJR‐Leon Golberg Memorial Postdoctoral Training Program in Toxicology
(to A.T.‐L.), and the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution,
with funding provided by the J. Seward Johnson Fund and The Walter A. and Hope Noyes Smith
Chair (to A.T‐L)
Morphological and histological placental characteristics in relation to pregnancy outcome in an unselected population
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Stress detection using wearable physiological sensors
As the population increases in the world, the ratio of health carers is rapidly decreasing. Therefore, there is an urgent need to create new technologies to monitor the physical and mental health of people during their daily life. In particular, negative mental states like depression and anxiety are big problems in modern societies, usually due to stressful situations during everyday activities including work. This paper presents a machine learning approach for stress detection on people using wearable physiological sensors with the �final aim of improving their quality of life. The presented technique can monitor the state of the subject continuously and classify it into "stressful" or "non-stressful" situations. Our classification results show that this method is a good starting point towards real-time stress detection
Migratory bird hunting activity and harvest during the 2005 and 2006 hunting seasons: Preliminary Estimates
Table of Contents
Abstract ………………………………………………………………………… 1 Introduction ……………………………………………………………………. 1 Design and Methods ……………………………………………………………. 1 Results and Discussion …………………………………………………………. 3 Waterfowl harvest estimates Species, state, flyway …………………………………………………… 8 Special seasons …………………………………………………………. 29 Canada harvest ...………………………………………………………. 32 Long-term trends graphs …………………………………………….…. 34 Waterfowl age and sex ratios …….………………………………………… 36 Long-term trends graphs …………………………………………….…. 49 Dove and pigeon estimates …………………………………………………. 53 Woodcock estimates ………………………………………………………… 55 Snipe, coot, gallinule, and rail estimates ……………………………………. 56 Species-specific rail estimates ………………………………………………. 6
Migratory bird hunting activity and harvest during the 1999 and 2000 hunting seasons Final Report April 2006
National surveys of waterfowl, dove, band-tailed pigeon (Columba fasciata), American woodcock (Scolopax minor), common snipe (Gallinago gallinago), rail, gallinule, and American coot (Fulica americana) hunters were conducted during the 1999 and 2000 migratory bird hunting seasons. About 1.3 million waterfowl hunters harvested 16,188,300 (±3%) ducks and 3,455,700 (±5%) geese in 1999, and a similar number of waterfowl hunters harvested 15,966,200 (±4%) ducks and 3,716,000 (±7%) geese in 2000. Mallard (Anas platyrhynchos), gadwall (A. strepera), green-winged teal (A. crecca), wood duck (Aix sponsa), and blue-winged teal (A. discors) were the most-harvested duck species, and Canada goose (Branta canadensis) was the predominant goose species in the harvest. About 1.2 million dove hunters harvested 24,437,300 (±4%) mourning doves (Zenaida macroura) in 1999 and 26,295,300 (±4%) in 2000. Woodcock hunters numbered about 170,600 in 1999 and 154,500 in 2000, and they harvested 444,800 (±20%) birds in 1999 and 390,900 (±20%) in 2000. Among the lesser-hunted species, about 40,200 people hunted snipe in 1999 (29,200 in 2000), and they harvested 276,500 (±56%) and 86,400 (±52%) snipe in 1999 and 2000, respectively; rail hunters (11,900 in 1999 and 6,900 in 2000) harvested 31,600 (±41%) rails in 1999 and 15,300 (±56%) rails in 2000; about 4,000 hunters harvested 32,900 (±74%) gallinules in 1999 and 20,900 (±70%) in 2000; and about 40,000 coot hunters harvested 236,000 (±26%) coots in 1999 and 335,000 (±45%) in 2000
Migratory bird hunting activity and harvest during the 1999 and 2000 hunting seasons Final Report April 2006
National surveys of waterfowl, dove, band-tailed pigeon (Columba fasciata), American woodcock (Scolopax minor), common snipe (Gallinago gallinago), rail, gallinule, and American coot (Fulica americana) hunters were conducted during the 1999 and 2000 migratory bird hunting seasons. About 1.3 million waterfowl hunters harvested 16,188,300 (±3%) ducks and 3,455,700 (±5%) geese in 1999, and a similar number of waterfowl hunters harvested 15,966,200 (±4%) ducks and 3,716,000 (±7%) geese in 2000. Mallard (Anas platyrhynchos), gadwall (A. strepera), green-winged teal (A. crecca), wood duck (Aix sponsa), and blue-winged teal (A. discors) were the most-harvested duck species, and Canada goose (Branta canadensis) was the predominant goose species in the harvest. About 1.2 million dove hunters harvested 24,437,300 (±4%) mourning doves (Zenaida macroura) in 1999 and 26,295,300 (±4%) in 2000. Woodcock hunters numbered about 170,600 in 1999 and 154,500 in 2000, and they harvested 444,800 (±20%) birds in 1999 and 390,900 (±20%) in 2000. Among the lesser-hunted species, about 40,200 people hunted snipe in 1999 (29,200 in 2000), and they harvested 276,500 (±56%) and 86,400 (±52%) snipe in 1999 and 2000, respectively; rail hunters (11,900 in 1999 and 6,900 in 2000) harvested 31,600 (±41%) rails in 1999 and 15,300 (±56%) rails in 2000; about 4,000 hunters harvested 32,900 (±74%) gallinules in 1999 and 20,900 (±70%) in 2000; and about 40,000 coot hunters harvested 236,000 (±26%) coots in 1999 and 335,000 (±45%) in 2000
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